[Pkg-gnupg-commit] [gnupg2] 107/180: dirmngr: Add basic libdns support
Daniel Kahn Gillmor
dkg at fifthhorseman.net
Sat Dec 24 22:29:15 UTC 2016
This is an automated email from the git hooks/post-receive script.
dkg pushed a commit to branch master
in repository gnupg2.
commit f6acd0426453d3a18536ca69d63baa0d971082ef
Author: Justus Winter <justus at g10code.com>
Date: Mon Dec 5 17:31:37 2016 +0100
dirmngr: Add basic libdns support
* dirmngr/dns.c: New file.
* dirmngr/dns.h: New file.
* dirmngr/Makefile.am (dirmngr_SOURCES): Add new files.
* dirmngr/dns-stuff.c: Include dns.h.xxx use libdns
(libdns): New global var for the libdns state.
(libdns_error_to_gpg_error): New.
(libdns_init): New.
(resolve_name_libdns): New.
(get_dns_cert_libdns): New stub.
(getsrv_libdns): New stub.
(get_dns_cname_libdns): New stub.
Signed-off-by: Justus Winter <justus at g10code.com>
---
dirmngr/Makefile.am | 7 +-
dirmngr/dns-stuff.c | 230 +-
dirmngr/dns.c | 11152 ++++++++++++++++++++++++++++++++++++++++++++++++++
dirmngr/dns.h | 1361 ++++++
4 files changed, 12736 insertions(+), 14 deletions(-)
diff --git a/dirmngr/Makefile.am b/dirmngr/Makefile.am
index 2a18a50..5c29468 100644
--- a/dirmngr/Makefile.am
+++ b/dirmngr/Makefile.am
@@ -59,6 +59,7 @@ dirmngr_SOURCES = dirmngr.c dirmngr.h server.c crlcache.c crlfetch.c \
loadswdb.c \
cdb.h cdblib.c misc.c dirmngr-err.h \
ocsp.c ocsp.h validate.c validate.h \
+ dns.c dns.h \
dns-stuff.c dns-stuff.h \
http.c http.h \
ks-action.c ks-action.h ks-engine.h \
@@ -102,7 +103,7 @@ dirmngr_client_LDADD = $(libcommon) \
dirmngr_client_LDFLAGS = $(extra_bin_ldflags)
-t_common_src = t-support.h
+t_common_src = t-support.h dns.c dns.h
t_common_ldadd = $(libcommon) $(LIBASSUAN_LIBS) $(LIBGCRYPT_LIBS) \
$(GPG_ERROR_LIBS) $(NETLIBS) \
$(NTBTLS_LIBS) $(LIBGNUTLS_LIBS) \
@@ -130,7 +131,7 @@ endif
# http tests
-t_http_SOURCES = t-http.c http.c dns-stuff.c
+t_http_SOURCES = $(t_common_src) t-http.c http.c dns-stuff.c
t_http_CFLAGS = -DWITHOUT_NPTH=1 \
$(LIBGCRYPT_CFLAGS) $(NTBTLS_CFLAGS) $(LIBGNUTLS_CFLAGS) \
$(GPG_ERROR_CFLAGS)
@@ -147,7 +148,7 @@ t_ldap_parse_uri_LDADD = $(ldaplibs) $(t_common_ldadd) $(DNSLIBS)
t_dns_stuff_CFLAGS = -DWITHOUT_NPTH=1 \
$(LIBGCRYPT_CFLAGS) $(GPG_ERROR_CFLAGS)
-t_dns_stuff_SOURCES = t-dns-stuff.c dns-stuff.c
+t_dns_stuff_SOURCES = $(t_common_src) t-dns-stuff.c dns-stuff.c
t_dns_stuff_LDADD = $(t_common_ldadd) $(DNSLIBS)
$(PROGRAMS) : $(libcommon) $(libcommonpth)
diff --git a/dirmngr/dns-stuff.c b/dirmngr/dns-stuff.c
index 6ec440d..a795363 100644
--- a/dirmngr/dns-stuff.c
+++ b/dirmngr/dns-stuff.c
@@ -46,6 +46,9 @@
#include <string.h>
#include <unistd.h>
+/* William Ahern's DNS library, included as a source copy. */
+#include "dns.h"
+
#ifdef WITHOUT_NPTH /* Give the Makefile a chance to build without Pth. */
# undef USE_NPTH
#endif
@@ -125,6 +128,8 @@ standard_resolver_p (void)
gpg_error_t
enable_dns_tormode (int new_circuit)
{
+ /* XXX: dns.c doesn't support SOCKS credentials. */
+
if (!*tor_credentials || new_circuit)
{
static unsigned int counter;
@@ -193,6 +198,191 @@ map_eai_to_gpg_error (int ec)
return err;
}
+struct
+{
+ struct dns_resolv_conf *resolv_conf;
+ struct dns_hosts *hosts;
+ struct dns_hints *hints;
+
+ struct sockaddr_storage socks_host;
+} libdns;
+
+static gpg_error_t
+libdns_error_to_gpg_error (int error)
+{
+ gpg_err_code_t ec;
+
+ switch (error)
+ {
+ case 0:
+ return 0;
+
+ default:
+ /* XXX */
+ fprintf (stderr, "libdns: %s\n", dns_strerror (error));
+ ec = GPG_ERR_GENERAL;
+ break;
+ }
+ return gpg_error (ec);
+}
+
+static gpg_error_t
+libdns_init (void)
+{
+ int error;
+
+ libdns.resolv_conf = dns_resconf_open (&error);
+ if (! libdns.resolv_conf)
+ goto leave;
+
+#if 0
+ error = dns_resconf_pton (&libdns.resolv_conf->nameserver[0],
+ "[127.0.0.1]:53");
+ if (error)
+ goto leave;
+#else
+ error = dns_resconf_loadpath (libdns.resolv_conf, "/etc/resolv.conf");
+ if (error)
+ goto leave;
+
+ error = dns_nssconf_loadpath (libdns.resolv_conf, "/etc/nsswitch.conf");
+ if (error)
+ goto leave;
+#endif
+
+ libdns.hosts = dns_hosts_open (&error);
+ if (! libdns.hosts)
+ goto leave;
+
+ /* dns_hints_local for stub mode, dns_hints_root for recursive. */
+ libdns.hints = dns_hints_local (libdns.resolv_conf, &error);
+ if (! libdns.hints)
+ goto leave;
+
+ /* XXX */
+ leave:
+ return libdns_error_to_gpg_error (error);
+}
+
+
+static gpg_error_t
+resolve_name_libdns (const char *name, unsigned short port,
+ int want_family, int want_socktype,
+ dns_addrinfo_t *r_dai, char **r_canonname)
+{
+ gpg_error_t err = 0;
+ dns_addrinfo_t daihead = NULL;
+ dns_addrinfo_t dai;
+ struct dns_resolver *res;
+ struct dns_addrinfo *ai = NULL;
+ struct addrinfo hints;
+ struct addrinfo *ent;
+ char portstr_[21];
+ char *portstr = portstr_;
+ int ret;
+
+ err = libdns_init ();
+ if (err)
+ return err;
+
+ *r_dai = NULL;
+ if (r_canonname)
+ *r_canonname = NULL;
+
+ memset (&hints, 0, sizeof hints);
+ hints.ai_family = want_family;
+ hints.ai_socktype = want_socktype;
+ hints.ai_flags = AI_ADDRCONFIG;
+ if (r_canonname)
+ hints.ai_flags |= AI_CANONNAME;
+
+ if (port)
+ snprintf (portstr_, sizeof portstr_, "%hu", port);
+ else
+ portstr = NULL;
+
+ res = dns_res_open (libdns.resolv_conf, libdns.hosts, libdns.hints, NULL,
+ dns_opts (/*.socks_host=&libdns.socks_host*/), &ret);
+ if (! res)
+ return libdns_error_to_gpg_error (ret);
+
+ ai = dns_ai_open (name, portstr, 0, &hints, res, &ret);
+ if (! ai)
+ goto leave;
+
+ /* XXX this is blocking. */
+ do {
+ ret = dns_ai_nextent (&ent, ai);
+ switch (ret) {
+ case 0:
+ if (r_canonname && ! *r_canonname && ent && ent->ai_canonname)
+ {
+ *r_canonname = xtrystrdup (ent->ai_canonname);
+ if (!*r_canonname)
+ {
+ err = gpg_error_from_syserror ();
+ goto leave;
+ }
+ }
+
+ dai = xtrymalloc (sizeof *dai + ent->ai_addrlen - 1);
+ if (dai == NULL)
+ {
+ err = ENOMEM;
+ goto leave;
+ }
+
+ dai->family = ent->ai_family;
+ dai->socktype = ent->ai_socktype;
+ dai->protocol = ent->ai_protocol;
+ dai->addrlen = ent->ai_addrlen;
+ memcpy (dai->addr, ent->ai_addr, ent->ai_addrlen);
+ dai->next = daihead;
+ daihead = dai;
+
+ xfree (ent);
+ break;
+
+ case ENOENT:
+ break;
+
+ case EAGAIN:
+ if (dns_ai_elapsed (ai) > 30)
+ log_assert (! "XXX: query timed-out");
+
+ dns_ai_poll (ai, 1);
+ break;
+
+ default:
+ goto leave;
+ }
+ } while (ret != ENOENT);
+
+ if (ret == ENOENT && daihead != NULL)
+ ret = 0; /* We got some results, we're good. */
+
+ leave:
+ dns_ai_close (ai);
+ dns_res_close (res);
+
+ if (ret && ! err)
+ err = libdns_error_to_gpg_error (ret);
+
+ if (err)
+ {
+ if (r_canonname)
+ {
+ xfree (*r_canonname);
+ *r_canonname = NULL;
+ }
+ free_dns_addrinfo (daihead);
+ }
+ else
+ *r_dai = daihead;
+
+ return err;
+}
+
/* Resolve a name using the standard system function. */
static gpg_error_t
@@ -376,11 +566,10 @@ resolve_dns_name (const char *name, unsigned short port,
int want_family, int want_socktype,
dns_addrinfo_t *r_ai, char **r_canonname)
{
-#ifdef NOTYET
if (!standard_resolver)
return resolve_name_libdns (name, port, want_family, want_socktype,
r_ai, r_canonname);
-#endif
+
return resolve_name_standard (name, port, want_family, want_socktype,
r_ai, r_canonname);
}
@@ -475,6 +664,16 @@ is_onion_address (const char *name)
}
+/* libdns version of get_dns_cert. */
+static gpg_error_t
+get_dns_cert_libdns (const char *name, int want_certtype,
+ void **r_key, size_t *r_keylen,
+ unsigned char **r_fpr, size_t *r_fprlen, char **r_url)
+{
+ return gpg_error (ENOTSUP);
+}
+
+
/* Standard resolver version of get_dns_cert. */
static gpg_error_t
get_dns_cert_standard (const char *name, int want_certtype,
@@ -701,11 +900,10 @@ get_dns_cert (const char *name, int want_certtype,
*r_fprlen = 0;
*r_url = NULL;
-#ifdef NOTYET
if (!standard_resolver)
return get_dns_cert_libdns (name, want_certtype, r_key, r_keylen,
r_fpr, r_fprlen, r_url);
-#endif
+
return get_dns_cert_standard (name, want_certtype, r_key, r_keylen,
r_fpr, r_fprlen, r_url);
}
@@ -728,6 +926,14 @@ priosort(const void *a,const void *b)
static int
getsrv_standard (const char *name, struct srventry **list)
{
+ return gpg_error (ENOTSUP);
+}
+
+
+/* libdns based helper for getsrv. */
+static int
+getsrv_libdns (const char *name, struct srventry **list)
+{
#ifdef HAVE_SYSTEM_RESOLVER
union {
unsigned char ans[2048];
@@ -850,12 +1056,8 @@ getsrv (const char *name, struct srventry **list)
*list = NULL;
- if (0)
- ;
-#ifdef NOTYET
- else if (!standard_resolver)
+ if (!standard_resolver)
srvcount = getsrv_libdns (name, list);
-#endif
else
srvcount = getsrv_standard (name, list);
@@ -939,6 +1141,14 @@ getsrv (const char *name, struct srventry **list)
}
+/* libdns version of get_dns_cname. */
+gpg_error_t
+get_dns_cname_libdns (const char *name, char **r_cname)
+{
+ return gpg_error (ENOTSUP);
+}
+
+
/* Standard resolver version of get_dns_cname. */
gpg_error_t
get_dns_cname_standard (const char *name, char **r_cname)
@@ -1022,10 +1232,8 @@ get_dns_cname (const char *name, char **r_cname)
{
*r_cname = NULL;
-#ifdef NOTYET
if (!standard_resolver)
return get_dns_cname_libdns (name, r_cname);
-#endif
return get_dns_cname_standard (name, r_cname);
}
diff --git a/dirmngr/dns.c b/dirmngr/dns.c
new file mode 100644
index 0000000..f29158c
--- /dev/null
+++ b/dirmngr/dns.c
@@ -0,0 +1,11152 @@
+/* ==========================================================================
+ * dns.c - Recursive, Reentrant DNS Resolver.
+ * --------------------------------------------------------------------------
+ * Copyright (c) 2008, 2009, 2010, 2012-2016 William Ahern
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to permit
+ * persons to whom the Software is furnished to do so, subject to the
+ * following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+ * NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * ==========================================================================
+ */
+#if HAVE_CONFIG_H
+#include "config.h"
+#elif !defined _GNU_SOURCE
+#define _GNU_SOURCE 1
+#endif
+
+#include <limits.h> /* INT_MAX */
+#include <stdarg.h> /* va_list va_start va_end */
+#include <stddef.h> /* offsetof() */
+#ifdef _WIN32
+/* JW: This breaks our mingw build: #define uint32_t unsigned int */
+#else
+#include <stdint.h> /* uint32_t */
+#endif
+#include <stdlib.h> /* malloc(3) realloc(3) free(3) rand(3) random(3) arc4random(3) */
+#include <stdio.h> /* FILE fopen(3) fclose(3) getc(3) rewind(3) vsnprintf(3) */
+#include <string.h> /* memcpy(3) strlen(3) memmove(3) memchr(3) memcmp(3) strchr(3) strsep(3) strcspn(3) */
+#include <strings.h> /* strcasecmp(3) strncasecmp(3) */
+#include <ctype.h> /* isspace(3) isdigit(3) */
+#include <time.h> /* time_t time(2) difftime(3) */
+#include <signal.h> /* SIGPIPE sigemptyset(3) sigaddset(3) sigpending(2) sigprocmask(2) pthread_sigmask(3) sigtimedwait(2) */
+#include <errno.h> /* errno EINVAL ENOENT */
+#undef NDEBUG
+#include <assert.h> /* assert(3) */
+
+#if _WIN32
+#ifndef FD_SETSIZE
+#define FD_SETSIZE 256
+#endif
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#else
+#include <sys/time.h> /* gettimeofday(2) */
+#include <sys/types.h> /* FD_SETSIZE socklen_t */
+#include <sys/select.h> /* FD_ZERO FD_SET fd_set select(2) */
+#include <sys/socket.h> /* AF_INET AF_INET6 AF_UNIX struct sockaddr struct sockaddr_in struct sockaddr_in6 socket(2) */
+#if defined(AF_UNIX)
+#include <sys/un.h> /* struct sockaddr_un */
+#endif
+#include <fcntl.h> /* F_SETFD F_GETFL F_SETFL O_NONBLOCK fcntl(2) */
+#include <unistd.h> /* _POSIX_THREADS gethostname(3) close(2) */
+#include <poll.h> /* POLLIN POLLOUT */
+#include <netinet/in.h> /* struct sockaddr_in struct sockaddr_in6 */
+#include <arpa/inet.h> /* inet_pton(3) inet_ntop(3) htons(3) ntohs(3) */
+#include <netdb.h> /* struct addrinfo */
+#endif
+
+#include "dns.h"
+
+
+/*
+ * C O M P I L E R V E R S I O N & F E A T U R E D E T E C T I O N
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_GNUC_2VER(M, m, p) (((M) * 10000) + ((m) * 100) + (p))
+#define DNS_GNUC_PREREQ(M, m, p) (__GNUC__ > 0 && DNS_GNUC_2VER(__GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__) >= DNS_GNUC_2VER((M), (m), (p)))
+
+#define DNS_MSC_2VER(M, m, p) ((((M) + 6) * 10000000) + ((m) * 1000000) + (p))
+#define DNS_MSC_PREREQ(M, m, p) (_MSC_VER_FULL > 0 && _MSC_VER_FULL >= DNS_MSC_2VER((M), (m), (p)))
+
+#define DNS_SUNPRO_PREREQ(M, m, p) (__SUNPRO_C > 0 && __SUNPRO_C >= 0x ## M ## m ## p)
+
+#if defined __has_builtin
+#define dns_has_builtin(x) __has_builtin(x)
+#else
+#define dns_has_builtin(x) 0
+#endif
+
+#if defined __has_extension
+#define dns_has_extension(x) __has_extension(x)
+#else
+#define dns_has_extension(x) 0
+#endif
+
+#ifndef HAVE___ASSUME
+#define HAVE___ASSUME DNS_MSC_PREREQ(8,0,0)
+#endif
+
+#ifndef HAVE___BUILTIN_TYPES_COMPATIBLE_P
+#define HAVE___BUILTIN_TYPES_COMPATIBLE_P (DNS_GNUC_PREREQ(3,1,1) || __clang__)
+#endif
+
+#ifndef HAVE___BUILTIN_UNREACHABLE
+#define HAVE___BUILTIN_UNREACHABLE (DNS_GNUC_PREREQ(4,5,0) || dns_has_builtin(__builtin_unreachable))
+#endif
+
+#ifndef HAVE_PRAGMA_MESSAGE
+#define HAVE_PRAGMA_MESSAGE (DNS_GNUC_PREREQ(4,4,0) || __clang__ || _MSC_VER)
+#endif
+
+
+/*
+ * C O M P I L E R A N N O T A T I O N S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#if __GNUC__
+#define DNS_NOTUSED __attribute__((unused))
+#define DNS_NORETURN __attribute__((noreturn))
+#else
+#define DNS_NOTUSED
+#define DNS_NORETURN
+#endif
+
+#if __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-parameter"
+#pragma clang diagnostic ignored "-Wmissing-field-initializers"
+#elif DNS_GNUC_PREREQ(4,6,0)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+#pragma GCC diagnostic ignored "-Wmissing-field-initializers"
+#endif
+
+
+/*
+ * S T A N D A R D M A C R O S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#if HAVE___BUILTIN_TYPES_COMPATIBLE_P
+#define dns_same_type(a, b, def) __builtin_types_compatible_p(__typeof__ (a), __typeof__ (b))
+#else
+#define dns_same_type(a, b, def) (def)
+#endif
+#define dns_isarray(a) (!dns_same_type((a), (&(a)[0]), 0))
+/* NB: "_" field silences Sun Studio "zero-sized struct/union" error diagnostic */
+#define dns_inline_assert(cond) ((void)(sizeof (struct { int:-!(cond); int _; })))
+
+#if HAVE___ASSUME
+#define dns_assume(cond) __assume(cond)
+#elif HAVE___BUILTIN_UNREACHABLE
+#define dns_assume(cond) do { if (!(cond)) __builtin_unreachable(); } while (0)
+#else
+#define dns_assume(cond) do { (void)(cond); } while (0)
+#endif
+
+#ifndef lengthof
+#define lengthof(a) (dns_inline_assert(dns_isarray(a)), (sizeof (a) / sizeof (a)[0]))
+#endif
+
+#ifndef endof
+#define endof(a) (dns_inline_assert(dns_isarray(a)), &(a)[lengthof((a))])
+#endif
+
+
+/*
+ * M I S C E L L A N E O U S C O M P A T
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#if _WIN32 || _WIN64
+#define PRIuZ "Iu"
+#else
+#define PRIuZ "zu"
+#endif
+
+#ifndef DNS_THREAD_SAFE
+#if (defined _REENTRANT || defined _THREAD_SAFE) && _POSIX_THREADS > 0
+#define DNS_THREAD_SAFE 1
+#else
+#define DNS_THREAD_SAFE 0
+#endif
+#endif
+
+#ifndef HAVE__STATIC_ASSERT
+#define HAVE__STATIC_ASSERT \
+ (dns_has_extension(c_static_assert) || DNS_GNUC_PREREQ(4,6,0) || \
+ __C11FEATURES__ || __STDC_VERSION__ >= 201112L)
+#endif
+
+#ifndef HAVE_STATIC_ASSERT
+#if DNS_GNUC_PREREQ(0,0,0) && !DNS_GNUC_PREREQ(4,6,0)
+#define HAVE_STATIC_ASSERT 0 /* glibc doesn't check GCC version */
+#else
+#define HAVE_STATIC_ASSERT (defined static_assert)
+#endif
+#endif
+
+#if HAVE_STATIC_ASSERT
+#define dns_static_assert(cond, msg) static_assert(cond, msg)
+#elif HAVE__STATIC_ASSERT
+#define dns_static_assert(cond, msg) _Static_assert(cond, msg)
+#else
+#define dns_static_assert(cond, msg) extern char DNS_PP_XPASTE(dns_assert_, __LINE__)[sizeof (int[1 - 2*!(cond)])]
+#endif
+
+
+/*
+ * D E B U G M A C R O S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+int *dns_debug_p(void) {
+ static int debug;
+
+ return &debug;
+} /* dns_debug_p() */
+
+#if DNS_DEBUG
+
+#undef DNS_DEBUG
+#define DNS_DEBUG dns_debug
+
+#define DNS_SAY_(fmt, ...) \
+ do { if (DNS_DEBUG > 0) fprintf(stderr, fmt "%.1s", __func__, __LINE__, __VA_ARGS__); } while (0)
+#define DNS_SAY(...) DNS_SAY_("@@ (%s:%d) " __VA_ARGS__, "\n")
+#define DNS_HAI DNS_SAY("HAI")
+
+#define DNS_SHOW_(P, fmt, ...) do { \
+ if (DNS_DEBUG > 1) { \
+ fprintf(stderr, "@@ BEGIN * * * * * * * * * * * *\n"); \
+ fprintf(stderr, "@@ " fmt "%.0s\n", __VA_ARGS__); \
+ dns_p_dump((P), stderr); \
+ fprintf(stderr, "@@ END * * * * * * * * * * * * *\n\n"); \
+ } \
+} while (0)
+
+#define DNS_SHOW(...) DNS_SHOW_(__VA_ARGS__, "")
+
+#else /* !DNS_DEBUG */
+
+#undef DNS_DEBUG
+#define DNS_DEBUG 0
+
+#define DNS_SAY(...)
+#define DNS_HAI
+#define DNS_SHOW(...)
+
+#endif /* DNS_DEBUG */
+
+#define DNS_CARP(...) DNS_SAY(__VA_ARGS__)
+
+
+/*
+ * V E R S I O N R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+const char *dns_vendor(void) {
+ return DNS_VENDOR;
+} /* dns_vendor() */
+
+
+int dns_v_rel(void) {
+ return DNS_V_REL;
+} /* dns_v_rel() */
+
+
+int dns_v_abi(void) {
+ return DNS_V_ABI;
+} /* dns_v_abi() */
+
+
+int dns_v_api(void) {
+ return DNS_V_API;
+} /* dns_v_api() */
+
+
+/*
+ * E R R O R R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#if _WIN32
+
+#define DNS_EINTR WSAEINTR
+#define DNS_EINPROGRESS WSAEINPROGRESS
+#define DNS_EISCONN WSAEISCONN
+#define DNS_EWOULDBLOCK WSAEWOULDBLOCK
+#define DNS_EALREADY WSAEALREADY
+#define DNS_EAGAIN EAGAIN
+#define DNS_ETIMEDOUT WSAETIMEDOUT
+
+#define dns_syerr() ((int)GetLastError())
+#define dns_soerr() ((int)WSAGetLastError())
+
+#else
+
+#define DNS_EINTR EINTR
+#define DNS_EINPROGRESS EINPROGRESS
+#define DNS_EISCONN EISCONN
+#define DNS_EWOULDBLOCK EWOULDBLOCK
+#define DNS_EALREADY EALREADY
+#define DNS_EAGAIN EAGAIN
+#define DNS_ETIMEDOUT ETIMEDOUT
+
+#define dns_syerr() errno
+#define dns_soerr() errno
+
+#endif
+
+
+const char *dns_strerror(int error) {
+ switch (error) {
+ case DNS_ENOBUFS:
+ return "DNS packet buffer too small";
+ case DNS_EILLEGAL:
+ return "Illegal DNS RR name or data";
+ case DNS_EORDER:
+ return "Attempt to push RR out of section order";
+ case DNS_ESECTION:
+ return "Invalid section specified";
+ case DNS_EUNKNOWN:
+ return "Unknown DNS error";
+ case DNS_EADDRESS:
+ return "Invalid textual address form";
+ case DNS_ENOQUERY:
+ return "Bad execution state (missing query packet)";
+ case DNS_ENOANSWER:
+ return "Bad execution state (missing answer packet)";
+ case DNS_EFETCHED:
+ return "Answer already fetched";
+ case DNS_ESERVICE:
+ return "The service passed was not recognized for the specified socket type";
+ case DNS_ENONAME:
+ return "The name does not resolve for the supplied parameters";
+ case DNS_EFAIL:
+ return "A non-recoverable error occurred when attempting to resolve the name";
+ case DNS_ECONNFIN:
+ return "Connection closed";
+ case DNS_EVERIFY:
+ return "Reply failed verification";
+ default:
+ return strerror(error);
+ } /* switch() */
+} /* dns_strerror() */
+
+
+/*
+ * A T O M I C R O U T I N E S
+ *
+ * Use GCC's __atomic built-ins if possible. Unlike the __sync built-ins, we
+ * can use the preprocessor to detect API and, more importantly, ISA
+ * support. We want to avoid linking headaches where the API depends on an
+ * external library if the ISA (e.g. i386) doesn't support lockless
+ * operation.
+ *
+ * TODO: Support C11's atomic API. Although that may require some finesse
+ * with how we define some public types, such as dns_atomic_t and struct
+ * dns_resolv_conf.
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#ifndef HAVE___ATOMIC_FETCH_ADD
+#define HAVE___ATOMIC_FETCH_ADD (defined __ATOMIC_RELAXED)
+#endif
+
+#ifndef HAVE___ATOMIC_FETCH_SUB
+#define HAVE___ATOMIC_FETCH_SUB HAVE___ATOMIC_FETCH_ADD
+#endif
+
+#ifndef DNS_ATOMIC_FETCH_ADD
+#if HAVE___ATOMIC_FETCH_ADD && __GCC_ATOMIC_LONG_LOCK_FREE == 2
+#define DNS_ATOMIC_FETCH_ADD(i) __atomic_fetch_add((i), 1, __ATOMIC_RELAXED)
+#else
+#pragma message("no atomic_fetch_add available")
+#define DNS_ATOMIC_FETCH_ADD(i) ((*(i))++)
+#endif
+#endif
+
+#ifndef DNS_ATOMIC_FETCH_SUB
+#if HAVE___ATOMIC_FETCH_SUB && __GCC_ATOMIC_LONG_LOCK_FREE == 2
+#define DNS_ATOMIC_FETCH_SUB(i) __atomic_fetch_sub((i), 1, __ATOMIC_RELAXED)
+#else
+#pragma message("no atomic_fetch_sub available")
+#define DNS_ATOMIC_FETCH_SUB(i) ((*(i))--)
+#endif
+#endif
+
+static inline unsigned dns_atomic_fetch_add(dns_atomic_t *i) {
+ return DNS_ATOMIC_FETCH_ADD(i);
+} /* dns_atomic_fetch_add() */
+
+
+static inline unsigned dns_atomic_fetch_sub(dns_atomic_t *i) {
+ return DNS_ATOMIC_FETCH_SUB(i);
+} /* dns_atomic_fetch_sub() */
+
+
+/*
+ * C R Y P T O R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * P R N G
+ */
+
+#ifndef DNS_RANDOM
+#if defined(HAVE_ARC4RANDOM) \
+ || defined(__OpenBSD__) \
+ || defined(__FreeBSD__) \
+ || defined(__NetBSD__) \
+ || defined(__APPLE__)
+#define DNS_RANDOM arc4random
+#elif __linux
+#define DNS_RANDOM random
+#else
+#define DNS_RANDOM rand
+#endif
+#endif
+
+#define DNS_RANDOM_arc4random 1
+#define DNS_RANDOM_random 2
+#define DNS_RANDOM_rand 3
+#define DNS_RANDOM_RAND_bytes 4
+
+#define DNS_RANDOM_OPENSSL (DNS_RANDOM_RAND_bytes == DNS_PP_XPASTE(DNS_RANDOM_, DNS_RANDOM))
+
+#if DNS_RANDOM_OPENSSL
+#include <openssl/rand.h>
+#endif
+
+static unsigned dns_random_(void) {
+#if DNS_RANDOM_OPENSSL
+ unsigned r;
+ _Bool ok;
+
+ ok = (1 == RAND_bytes((unsigned char *)&r, sizeof r));
+ assert(ok && "1 == RAND_bytes()");
+
+ return r;
+#else
+ return DNS_RANDOM();
+#endif
+} /* dns_random_() */
+
+dns_random_f **dns_random_p(void) {
+ static dns_random_f *random_f = &dns_random_;
+
+ return &random_f;
+} /* dns_random_p() */
+
+
+/*
+ * P E R M U T A T I O N G E N E R A T O R
+ */
+
+#define DNS_K_TEA_KEY_SIZE 16
+#define DNS_K_TEA_BLOCK_SIZE 8
+#define DNS_K_TEA_CYCLES 32
+#define DNS_K_TEA_MAGIC 0x9E3779B9U
+
+struct dns_k_tea {
+ uint32_t key[DNS_K_TEA_KEY_SIZE / sizeof (uint32_t)];
+ unsigned cycles;
+}; /* struct dns_k_tea */
+
+
+static void dns_k_tea_init(struct dns_k_tea *tea, uint32_t key[], unsigned cycles) {
+ memcpy(tea->key, key, sizeof tea->key);
+
+ tea->cycles = (cycles)? cycles : DNS_K_TEA_CYCLES;
+} /* dns_k_tea_init() */
+
+
+static void dns_k_tea_encrypt(struct dns_k_tea *tea, uint32_t v[], uint32_t *w) {
+ uint32_t y, z, sum, n;
+
+ y = v[0];
+ z = v[1];
+ sum = 0;
+
+ for (n = 0; n < tea->cycles; n++) {
+ sum += DNS_K_TEA_MAGIC;
+ y += ((z << 4) + tea->key[0]) ^ (z + sum) ^ ((z >> 5) + tea->key[1]);
+ z += ((y << 4) + tea->key[2]) ^ (y + sum) ^ ((y >> 5) + tea->key[3]);
+ }
+
+ w[0] = y;
+ w[1] = z;
+
+ return /* void */;
+} /* dns_k_tea_encrypt() */
+
+
+/*
+ * Permutation generator, based on a Luby-Rackoff Feistel construction.
+ *
+ * Specifically, this is a generic balanced Feistel block cipher using TEA
+ * (another block cipher) as the pseudo-random function, F. At best it's as
+ * strong as F (TEA), notwithstanding the seeding. F could be AES, SHA-1, or
+ * perhaps Bernstein's Salsa20 core; I am naively trying to keep things
+ * simple.
+ *
+ * The generator can create a permutation of any set of numbers, as long as
+ * the size of the set is an even power of 2. This limitation arises either
+ * out of an inherent property of balanced Feistel constructions, or by my
+ * own ignorance. I'll tackle an unbalanced construction after I wrap my
+ * head around Schneier and Kelsey's paper.
+ *
+ * CAVEAT EMPTOR. IANAC.
+ */
+#define DNS_K_PERMUTOR_ROUNDS 8
+
+struct dns_k_permutor {
+ unsigned stepi, length, limit;
+ unsigned shift, mask, rounds;
+
+ struct dns_k_tea tea;
+}; /* struct dns_k_permutor */
+
+
+static inline unsigned dns_k_permutor_powof(unsigned n) {
+ unsigned m, i = 0;
+
+ for (m = 1; m < n; m <<= 1, i++)
+ ;;
+
+ return i;
+} /* dns_k_permutor_powof() */
+
+static void dns_k_permutor_init(struct dns_k_permutor *p, unsigned low, unsigned high) {
+ uint32_t key[DNS_K_TEA_KEY_SIZE / sizeof (uint32_t)];
+ unsigned width, i;
+
+ p->stepi = 0;
+
+ p->length = (high - low) + 1;
+ p->limit = high;
+
+ width = dns_k_permutor_powof(p->length);
+ width += width % 2;
+
+ p->shift = width / 2;
+ p->mask = (1U << p->shift) - 1;
+ p->rounds = DNS_K_PERMUTOR_ROUNDS;
+
+ for (i = 0; i < lengthof(key); i++)
+ key[i] = dns_random();
+
+ dns_k_tea_init(&p->tea, key, 0);
+
+ return /* void */;
+} /* dns_k_permutor_init() */
+
+
+static unsigned dns_k_permutor_F(struct dns_k_permutor *p, unsigned k, unsigned x) {
+ uint32_t in[DNS_K_TEA_BLOCK_SIZE / sizeof (uint32_t)], out[DNS_K_TEA_BLOCK_SIZE / sizeof (uint32_t)];
+
+ memset(in, '\0', sizeof in);
+
+ in[0] = k;
+ in[1] = x;
+
+ dns_k_tea_encrypt(&p->tea, in, out);
+
+ return p->mask & out[0];
+} /* dns_k_permutor_F() */
+
+
+static unsigned dns_k_permutor_E(struct dns_k_permutor *p, unsigned n) {
+ unsigned l[2], r[2];
+ unsigned i;
+
+ i = 0;
+ l[i] = p->mask & (n >> p->shift);
+ r[i] = p->mask & (n >> 0);
+
+ do {
+ l[(i + 1) % 2] = r[i % 2];
+ r[(i + 1) % 2] = l[i % 2] ^ dns_k_permutor_F(p, i, r[i % 2]);
+
+ i++;
+ } while (i < p->rounds - 1);
+
+ return ((l[i % 2] & p->mask) << p->shift) | ((r[i % 2] & p->mask) << 0);
+} /* dns_k_permutor_E() */
+
+
+DNS_NOTUSED static unsigned dns_k_permutor_D(struct dns_k_permutor *p, unsigned n) {
+ unsigned l[2], r[2];
+ unsigned i;
+
+ i = p->rounds - 1;
+ l[i % 2] = p->mask & (n >> p->shift);
+ r[i % 2] = p->mask & (n >> 0);
+
+ do {
+ i--;
+
+ r[i % 2] = l[(i + 1) % 2];
+ l[i % 2] = r[(i + 1) % 2] ^ dns_k_permutor_F(p, i, l[(i + 1) % 2]);
+ } while (i > 0);
+
+ return ((l[i % 2] & p->mask) << p->shift) | ((r[i % 2] & p->mask) << 0);
+} /* dns_k_permutor_D() */
+
+
+static unsigned dns_k_permutor_step(struct dns_k_permutor *p) {
+ unsigned n;
+
+ do {
+ n = dns_k_permutor_E(p, p->stepi++);
+ } while (n >= p->length);
+
+ return n + (p->limit + 1 - p->length);
+} /* dns_k_permutor_step() */
+
+
+/*
+ * Simple permutation box. Useful for shuffling rrsets from an iterator.
+ * Uses AES s-box to provide good diffusion.
+ *
+ * Seems to pass muster under runs test.
+ *
+ * $ for i in 0 1 2 3 4 5 6 7 8 9; do ./dns shuffle-16 > /tmp/out; done
+ * $ R -q -f /dev/stdin 2>/dev/null <<-EOF | awk '/p-value/{ print $8 }'
+ * library(lawstat)
+ * runs.test(scan(file="/tmp/out"))
+ * EOF
+ */
+static unsigned short dns_k_shuffle16(unsigned short n, unsigned s) {
+ static const unsigned char sbox[256] =
+ { 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5,
+ 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
+ 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0,
+ 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
+ 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc,
+ 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
+ 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a,
+ 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
+ 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0,
+ 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
+ 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b,
+ 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
+ 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85,
+ 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
+ 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5,
+ 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
+ 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17,
+ 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
+ 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88,
+ 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
+ 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c,
+ 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
+ 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9,
+ 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
+ 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6,
+ 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
+ 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e,
+ 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
+ 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94,
+ 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
+ 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68,
+ 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 };
+ unsigned char a, b;
+ unsigned i;
+
+ a = 0xff & (n >> 0);
+ b = 0xff & (n >> 8);
+
+ for (i = 0; i < 4; i++) {
+ a ^= 0xff & s;
+ a = sbox[a] ^ b;
+ b = sbox[b] ^ a;
+ s >>= 8;
+ }
+
+ return ((0xff00 & (a << 8)) | (0x00ff & (b << 0)));
+} /* dns_k_shuffle16() */
+
+/*
+ * S T A T E M A C H I N E R O U T I N E S
+ *
+ * Application code should define DNS_SM_RESTORE and DNS_SM_SAVE, and the
+ * local variable pc.
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_SM_ENTER \
+ do { \
+ static const int pc0 = __LINE__; \
+ DNS_SM_RESTORE; \
+ switch (pc0 + pc) { \
+ case __LINE__: (void)0
+
+#define DNS_SM_SAVE_AND_DO(do_statement) \
+ do { \
+ pc = __LINE__ - pc0; \
+ DNS_SM_SAVE; \
+ do_statement; \
+ case __LINE__: (void)0; \
+ } while (0)
+
+#define DNS_SM_YIELD(rv) \
+ DNS_SM_SAVE_AND_DO(return (rv))
+
+#define DNS_SM_EXIT \
+ do { goto leave; } while (0)
+
+#define DNS_SM_LEAVE \
+ leave: (void)0; \
+ DNS_SM_SAVE_AND_DO(break); \
+ } \
+ } while (0)
+
+/*
+ * U T I L I T Y R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_MAXINTERVAL 300
+
+struct dns_clock {
+ time_t sample, elapsed;
+}; /* struct dns_clock */
+
+static void dns_begin(struct dns_clock *clk) {
+ clk->sample = time(0);
+ clk->elapsed = 0;
+} /* dns_begin() */
+
+static time_t dns_elapsed(struct dns_clock *clk) {
+ time_t curtime;
+
+ if ((time_t)-1 == time(&curtime))
+ return clk->elapsed;
+
+ if (curtime > clk->sample)
+ clk->elapsed += (time_t)DNS_PP_MIN(difftime(curtime, clk->sample), DNS_MAXINTERVAL);
+
+ clk->sample = curtime;
+
+ return clk->elapsed;
+} /* dns_elapsed() */
+
+
+DNS_NOTUSED static size_t dns_strnlen(const char *src, size_t m) {
+ size_t n = 0;
+
+ while (*src++ && n < m)
+ ++n;
+
+ return n;
+} /* dns_strnlen() */
+
+
+DNS_NOTUSED static size_t dns_strnlcpy(char *dst, size_t lim, const char *src, size_t max) {
+ size_t len = dns_strnlen(src, max), n;
+
+ if (lim > 0) {
+ n = DNS_PP_MIN(lim - 1, len);
+ memcpy(dst, src, n);
+ dst[n] = '\0';
+ }
+
+ return len;
+} /* dns_strnlcpy() */
+
+
+#define DNS_HAVE_SOCKADDR_UN (defined AF_UNIX && !defined _WIN32)
+
+static size_t dns_af_len(int af) {
+ static const size_t table[AF_MAX] = {
+ [AF_INET6] = sizeof (struct sockaddr_in6),
+ [AF_INET] = sizeof (struct sockaddr_in),
+#if DNS_HAVE_SOCKADDR_UN
+ [AF_UNIX] = sizeof (struct sockaddr_un),
+#endif
+ };
+
+ return table[af];
+} /* dns_af_len() */
+
+#define dns_sa_family(sa) (((struct sockaddr *)(sa))->sa_family)
+
+#define dns_sa_len(sa) dns_af_len(dns_sa_family(sa))
+
+
+#define DNS_SA_NOPORT &dns_sa_noport
+static unsigned short dns_sa_noport;
+
+static unsigned short *dns_sa_port(int af, void *sa) {
+ switch (af) {
+ case AF_INET6:
+ return &((struct sockaddr_in6 *)sa)->sin6_port;
+ case AF_INET:
+ return &((struct sockaddr_in *)sa)->sin_port;
+ default:
+ return DNS_SA_NOPORT;
+ }
+} /* dns_sa_port() */
+
+
+static void *dns_sa_addr(int af, const void *sa, socklen_t *size) {
+ switch (af) {
+ case AF_INET6: {
+ struct in6_addr *in6 = &((struct sockaddr_in6 *)sa)->sin6_addr;
+
+ if (size)
+ *size = sizeof *in6;
+
+ return in6;
+ }
+ case AF_INET: {
+ struct in_addr *in = &((struct sockaddr_in *)sa)->sin_addr;
+
+ if (size)
+ *size = sizeof *in;
+
+ return in;
+ }
+ default:
+ if (size)
+ *size = 0;
+
+ return 0;
+ }
+} /* dns_sa_addr() */
+
+
+#if DNS_HAVE_SOCKADDR_UN
+#define DNS_SUNPATHMAX (sizeof ((struct sockaddr_un *)0)->sun_path)
+#endif
+
+DNS_NOTUSED static void *dns_sa_path(void *sa, socklen_t *size) {
+ switch (dns_sa_family(sa)) {
+#if DNS_HAVE_SOCKADDR_UN
+ case AF_UNIX: {
+ char *path = ((struct sockaddr_un *)sa)->sun_path;
+
+ if (size)
+ *size = dns_strnlen(path, DNS_SUNPATHMAX);
+
+ return path;
+ }
+#endif
+ default:
+ if (size)
+ *size = 0;
+
+ return NULL;
+ }
+} /* dns_sa_path() */
+
+
+static int dns_sa_cmp(void *a, void *b) {
+ int cmp, af;
+
+ if ((cmp = dns_sa_family(a) - dns_sa_family(b)))
+ return cmp;
+
+ switch ((af = dns_sa_family(a))) {
+ case AF_INET: {
+ struct in_addr *a4, *b4;
+
+ if ((cmp = htons(*dns_sa_port(af, a)) - htons(*dns_sa_port(af, b))))
+ return cmp;
+
+ a4 = dns_sa_addr(af, a, NULL);
+ b4 = dns_sa_addr(af, b, NULL);
+
+ if (ntohl(a4->s_addr) < ntohl(b4->s_addr))
+ return -1;
+ if (ntohl(a4->s_addr) > ntohl(b4->s_addr))
+ return 1;
+
+ return 0;
+ }
+ case AF_INET6: {
+ struct in6_addr *a6, *b6;
+ size_t i;
+
+ if ((cmp = htons(*dns_sa_port(af, a)) - htons(*dns_sa_port(af, b))))
+ return cmp;
+
+ a6 = dns_sa_addr(af, a, NULL);
+ b6 = dns_sa_addr(af, b, NULL);
+
+ /* XXX: do we need to use in6_clearscope()? */
+ for (i = 0; i < sizeof a6->s6_addr; i++) {
+ if ((cmp = a6->s6_addr[i] - b6->s6_addr[i]))
+ return cmp;
+ }
+
+ return 0;
+ }
+#if DNS_HAVE_SOCKADDR_UN
+ case AF_UNIX: {
+ char a_path[DNS_SUNPATHMAX + 1], b_path[sizeof a_path];
+
+ dns_strnlcpy(a_path, sizeof a_path, dns_sa_path(a, NULL), DNS_SUNPATHMAX);
+ dns_strnlcpy(b_path, sizeof b_path, dns_sa_path(b, NULL), DNS_SUNPATHMAX);
+
+ return strcmp(a_path, b_path);
+ }
+#endif
+ default:
+ return -1;
+ }
+} /* dns_sa_cmp() */
+
+
+#if _WIN32
+static int dns_inet_pton(int af, const void *src, void *dst) {
+ union { struct sockaddr_in sin; struct sockaddr_in6 sin6; } u;
+
+ u.sin.sin_family = af;
+
+ if (0 != WSAStringToAddressA((void *)src, af, (void *)0, (struct sockaddr *)&u, &(int){ sizeof u }))
+ return -1;
+
+ switch (af) {
+ case AF_INET6:
+ *(struct in6_addr *)dst = u.sin6.sin6_addr;
+
+ return 1;
+ case AF_INET:
+ *(struct in_addr *)dst = u.sin.sin_addr;
+
+ return 1;
+ default:
+ return 0;
+ }
+} /* dns_inet_pton() */
+
+static const char *dns_inet_ntop(int af, const void *src, void *dst, unsigned long lim) {
+ union { struct sockaddr_in sin; struct sockaddr_in6 sin6; } u;
+
+ /* NOTE: WSAAddressToString will print .sin_port unless zeroed. */
+ memset(&u, 0, sizeof u);
+
+ u.sin.sin_family = af;
+
+ switch (af) {
+ case AF_INET6:
+ u.sin6.sin6_addr = *(struct in6_addr *)src;
+ break;
+ case AF_INET:
+ u.sin.sin_addr = *(struct in_addr *)src;
+
+ break;
+ default:
+ return 0;
+ }
+
+ if (0 != WSAAddressToStringA((struct sockaddr *)&u, dns_sa_len(&u), (void *)0, dst, &lim))
+ return 0;
+
+ return dst;
+} /* dns_inet_ntop() */
+#else
+#define dns_inet_pton(...) inet_pton(__VA_ARGS__)
+#define dns_inet_ntop(...) inet_ntop(__VA_ARGS__)
+#endif
+
+
+static dns_error_t dns_pton(int af, const void *src, void *dst) {
+ switch (dns_inet_pton(af, src, dst)) {
+ case 1:
+ return 0;
+ case -1:
+ return dns_soerr();
+ default:
+ return DNS_EADDRESS;
+ }
+} /* dns_pton() */
+
+
+static dns_error_t dns_ntop(int af, const void *src, void *dst, unsigned long lim) {
+ return (dns_inet_ntop(af, src, dst, lim))? 0 : dns_soerr();
+} /* dns_ntop() */
+
+
+size_t dns_strlcpy(char *dst, const char *src, size_t lim) {
+ char *d = dst;
+ char *e = &dst[lim];
+ const char *s = src;
+
+ if (d < e) {
+ do {
+ if ('\0' == (*d++ = *s++))
+ return s - src - 1;
+ } while (d < e);
+
+ d[-1] = '\0';
+ }
+
+ while (*s++ != '\0')
+ ;;
+
+ return s - src - 1;
+} /* dns_strlcpy() */
+
+
+size_t dns_strlcat(char *dst, const char *src, size_t lim) {
+ char *d = memchr(dst, '\0', lim);
+ char *e = &dst[lim];
+ const char *s = src;
+ const char *p;
+
+ if (d && d < e) {
+ do {
+ if ('\0' == (*d++ = *s++))
+ return d - dst - 1;
+ } while (d < e);
+
+ d[-1] = '\0';
+ }
+
+ p = s;
+
+ while (*s++ != '\0')
+ ;;
+
+ return lim + (s - p - 1);
+} /* dns_strlcat() */
+
+
+static void *dns_reallocarray(void *p, size_t nmemb, size_t size, dns_error_t *error) {
+ void *rp;
+
+ if (nmemb > 0 && SIZE_MAX / nmemb < size) {
+ *error = EOVERFLOW;
+ return NULL;
+ }
+
+ if (!(rp = realloc(p, nmemb * size)))
+ *error = (errno)? errno : EINVAL;
+
+ return rp;
+} /* dns_reallocarray() */
+
+
+#if _WIN32
+
+static char *dns_strsep(char **sp, const char *delim) {
+ char *p;
+
+ if (!(p = *sp))
+ return 0;
+
+ *sp += strcspn(p, delim);
+
+ if (**sp != '\0') {
+ **sp = '\0';
+ ++*sp;
+ } else
+ *sp = NULL;
+
+ return p;
+} /* dns_strsep() */
+
+#else
+#define dns_strsep(...) strsep(__VA_ARGS__)
+#endif
+
+
+#if _WIN32
+#define strcasecmp(...) _stricmp(__VA_ARGS__)
+#define strncasecmp(...) _strnicmp(__VA_ARGS__)
+#endif
+
+
+static inline _Bool dns_isalpha(unsigned char c) {
+ return isalpha(c);
+} /* dns_isalpha() */
+
+static inline _Bool dns_isdigit(unsigned char c) {
+ return isdigit(c);
+} /* dns_isdigit() */
+
+static inline _Bool dns_isalnum(unsigned char c) {
+ return isalnum(c);
+} /* dns_isalnum() */
+
+static inline _Bool dns_isspace(unsigned char c) {
+ return isspace(c);
+} /* dns_isspace() */
+
+static inline _Bool dns_isgraph(unsigned char c) {
+ return isgraph(c);
+} /* dns_isgraph() */
+
+
+static int dns_poll(int fd, short events, int timeout) {
+ fd_set rset, wset;
+
+ if (!events)
+ return 0;
+
+ assert(fd >= 0 && (unsigned)fd < FD_SETSIZE);
+
+ FD_ZERO(&rset);
+ FD_ZERO(&wset);
+
+ if (events & DNS_POLLIN)
+ FD_SET(fd, &rset);
+
+ if (events & DNS_POLLOUT)
+ FD_SET(fd, &wset);
+
+ select(fd + 1, &rset, &wset, 0, (timeout >= 0)? &(struct timeval){ timeout, 0 } : NULL);
+
+ return 0;
+} /* dns_poll() */
+
+
+#if !_WIN32
+DNS_NOTUSED static int dns_sigmask(int how, const sigset_t *set, sigset_t *oset) {
+#if DNS_THREAD_SAFE
+ return pthread_sigmask(how, set, oset);
+#else
+ return (0 == sigprocmask(how, set, oset))? 0 : errno;
+#endif
+} /* dns_sigmask() */
+#endif
+
+
+static size_t dns_send(int fd, const void *src, size_t len, int flags, dns_error_t *error) {
+ long n = send(fd, src, len, flags);
+
+ if (n < 0) {
+ *error = dns_soerr();
+ return 0;
+ } else {
+ *error = 0;
+ return n;
+ }
+} /* dns_send() */
+
+static size_t dns_recv(int fd, void *dst, size_t lim, int flags, dns_error_t *error) {
+ long n = recv(fd, dst, lim, flags);
+
+ if (n < 0) {
+ *error = dns_soerr();
+ return 0;
+ } else if (n == 0) {
+ *error = (lim > 0)? DNS_ECONNFIN : EINVAL;
+ return 0;
+ } else {
+ *error = 0;
+ return n;
+ }
+} /* dns_recv() */
+
+static size_t dns_send_nopipe(int fd, const void *src, size_t len, int flags, dns_error_t *_error) {
+#if _WIN32 || !defined SIGPIPE || defined SO_NOSIGPIPE
+ return dns_send(fd, src, len, flags, _error);
+#elif defined MSG_NOSIGNAL
+ return dns_send(fd, src, len, (flags|MSG_NOSIGNAL), _error);
+#elif _POSIX_REALTIME_SIGNALS > 0 /* require sigtimedwait */
+ /*
+ * SIGPIPE handling similar to the approach described in
+ * http://krokisplace.blogspot.com/2010/02/suppressing-sigpipe-in-library.html
+ */
+ sigset_t pending, blocked, piped;
+ size_t count;
+ int error;
+
+ sigemptyset(&pending);
+ sigpending(&pending);
+
+ if (!sigismember(&pending, SIGPIPE)) {
+ sigemptyset(&piped);
+ sigaddset(&piped, SIGPIPE);
+ sigemptyset(&blocked);
+
+ if ((error = dns_sigmask(SIG_BLOCK, &piped, &blocked)))
+ goto error;
+ }
+
+ count = dns_send(fd, src, len, flags, &error);
+
+ if (!sigismember(&pending, SIGPIPE)) {
+ int saved = error;
+
+ if (!count && error == EPIPE) {
+ while (-1 == sigtimedwait(&piped, NULL, &(struct timespec){ 0, 0 }) && errno == EINTR)
+ ;;
+ }
+
+ if ((error = dns_sigmask(SIG_SETMASK, &blocked, NULL)))
+ goto error;
+
+ error = saved;
+ }
+
+ *_error = error;
+ return count;
+error:
+ *_error = error;
+ return 0;
+#else
+#error "unable to suppress SIGPIPE"
+ return dns_send(fd, src, len, flags, _error);
+#endif
+} /* dns_send_nopipe() */
+
+
+static dns_error_t dns_connect(int fd, const struct sockaddr *addr, socklen_t addrlen) {
+ if (0 != connect(fd, addr, addrlen))
+ return dns_soerr();
+ return 0;
+} /* dns_connect() */
+
+
+#define DNS_FOPEN_STDFLAGS "rwabt+"
+
+static dns_error_t dns_fopen_addflag(char *dst, const char *src, size_t lim, int fc) {
+ char *p = dst, *pe = dst + lim;
+
+ /* copy standard flags */
+ while (*src && strchr(DNS_FOPEN_STDFLAGS, *src)) {
+ if (!(p < pe))
+ return ENOMEM;
+ *p++ = *src++;
+ }
+
+ /* append flag to standard flags */
+ if (!(p < pe))
+ return ENOMEM;
+ *p++ = fc;
+
+ /* copy remaining mode string, including '\0' */
+ do {
+ if (!(p < pe))
+ return ENOMEM;
+ } while ((*p++ = *src++));
+
+ return 0;
+} /* dns_fopen_addflag() */
+
+static FILE *dns_fopen(const char *path, const char *mode, dns_error_t *_error) {
+ FILE *fp;
+ char mode_cloexec[32];
+ int error;
+
+ assert(path && mode && *mode);
+ if (!*path) {
+ error = EINVAL;
+ goto error;
+ }
+
+#if _WIN32 || _WIN64
+ if ((error = dns_fopen_addflag(mode_cloexec, mode, sizeof mode_cloexec, 'N')))
+ goto error;
+ if (!(fp = fopen(path, mode_cloexec)))
+ goto syerr;
+#else
+ if ((error = dns_fopen_addflag(mode_cloexec, mode, sizeof mode_cloexec, 'e')))
+ goto error;
+ if (!(fp = fopen(path, mode_cloexec))) {
+ if (errno != EINVAL)
+ goto syerr;
+ if (!(fp = fopen(path, mode)))
+ goto syerr;
+ }
+#endif
+
+ return fp;
+syerr:
+ error = dns_syerr();
+error:
+ *_error = error;
+
+ return NULL;
+} /* dns_fopen() */
+
+
+struct dns_hxd_lines_i {
+ int pc;
+ size_t p;
+};
+
+#define DNS_SM_RESTORE \
+ do { \
+ pc = state->pc; \
+ sp = src + state->p; \
+ se = src + len; \
+ } while (0)
+#define DNS_SM_SAVE \
+ do { \
+ state->p = sp - src; \
+ state->pc = pc; \
+ } while (0)
+
+static size_t dns_hxd_lines(void *dst, size_t lim, const unsigned char *src, size_t len, struct dns_hxd_lines_i *state) {
+ static const unsigned char hex[] = "0123456789abcdef";
+ static const unsigned char tmpl[] = " | |\n";
+ unsigned char ln[sizeof tmpl];
+ const unsigned char *sp, *se;
+ unsigned char *h, *g;
+ unsigned i, n;
+ int pc;
+
+ DNS_SM_ENTER;
+
+ while (sp < se) {
+ memcpy(ln, tmpl, sizeof ln);
+
+ h = &ln[2];
+ g = &ln[53];
+
+ for (n = 0; n < 2; n++) {
+ for (i = 0; i < 8 && se - sp > 0; i++, sp++) {
+ h[0] = hex[0x0f & (*sp >> 4)];
+ h[1] = hex[0x0f & (*sp >> 0)];
+ h += 3;
+
+ *g++ = (dns_isgraph(*sp))? *sp : '.';
+ }
+
+ h++;
+ }
+
+ n = dns_strlcpy(dst, (char *)ln, lim);
+ DNS_SM_YIELD(n);
+ }
+
+ DNS_SM_EXIT;
+ DNS_SM_LEAVE;
+
+ return 0;
+}
+
+#undef DNS_SM_SAVE
+#undef DNS_SM_RESTORE
+
+/*
+ * A R I T H M E T I C R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_CHECK_OVERFLOW(error, r, f, ...) \
+ do { \
+ uintmax_t _r; \
+ *(error) = f(&_r, __VA_ARGS__); \
+ *(r) = _r; \
+ } while (0)
+
+static dns_error_t dns_clamp_overflow(uintmax_t *r, uintmax_t n, uintmax_t clamp) {
+ if (n > clamp) {
+ *r = clamp;
+ return ERANGE;
+ } else {
+ *r = n;
+ return 0;
+ }
+} /* dns_clamp_overflow() */
+
+static dns_error_t dns_add_overflow(uintmax_t *r, uintmax_t a, uintmax_t b, uintmax_t clamp) {
+ if (~a < b) {
+ *r = DNS_PP_MIN(clamp, ~UINTMAX_C(0));
+ return ERANGE;
+ } else {
+ return dns_clamp_overflow(r, a + b, clamp);
+ }
+} /* dns_add_overflow() */
+
+static dns_error_t dns_mul_overflow(uintmax_t *r, uintmax_t a, uintmax_t b, uintmax_t clamp) {
+ if (a > 0 && UINTMAX_MAX / a < b) {
+ *r = DNS_PP_MIN(clamp, ~UINTMAX_C(0));
+ return ERANGE;
+ } else {
+ return dns_clamp_overflow(r, a * b, clamp);
+ }
+} /* dns_mul_overflow() */
+
+/*
+ * F I X E D - S I Z E D B U F F E R R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_B_INIT(src, n) { \
+ (unsigned char *)(src), \
+ (unsigned char *)(src), \
+ (unsigned char *)(src) + (n), \
+}
+
+#define DNS_B_FROM(src, n) DNS_B_INIT((src), (n))
+#define DNS_B_INTO(src, n) DNS_B_INIT((src), (n))
+
+struct dns_buf {
+ const unsigned char *base;
+ unsigned char *p;
+ const unsigned char *pe;
+ dns_error_t error;
+ size_t overflow;
+}; /* struct dns_buf */
+
+static inline size_t
+dns_b_tell(struct dns_buf *b)
+{
+ return b->p - b->base;
+}
+
+static inline dns_error_t
+dns_b_setoverflow(struct dns_buf *b, size_t n, dns_error_t error)
+{
+ b->overflow += n;
+ return b->error = error;
+}
+
+DNS_NOTUSED static struct dns_buf *
+dns_b_into(struct dns_buf *b, void *src, size_t n)
+{
+ *b = (struct dns_buf)DNS_B_INTO(src, n);
+
+ return b;
+}
+
+static dns_error_t
+dns_b_putc(struct dns_buf *b, unsigned char uc)
+{
+ if (!(b->p < b->pe))
+ return dns_b_setoverflow(b, 1, DNS_ENOBUFS);
+
+ *b->p++ = uc;
+
+ return 0;
+}
+
+static dns_error_t
+dns_b_pputc(struct dns_buf *b, unsigned char uc, size_t p)
+{
+ size_t pe = b->pe - b->base;
+ if (pe <= p)
+ return dns_b_setoverflow(b, p - pe + 1, DNS_ENOBUFS);
+
+ *((unsigned char *)b->base + p) = uc;
+
+ return 0;
+}
+
+static inline dns_error_t
+dns_b_put16(struct dns_buf *b, uint16_t u)
+{
+ return dns_b_putc(b, u >> 8), dns_b_putc(b, u >> 0);
+}
+
+static inline dns_error_t
+dns_b_pput16(struct dns_buf *b, uint16_t u, size_t p)
+{
+ if (dns_b_pputc(b, u >> 8, p) || dns_b_pputc(b, u >> 0, p + 1))
+ return b->error;
+
+ return 0;
+}
+
+DNS_NOTUSED static inline dns_error_t
+dns_b_put32(struct dns_buf *b, uint32_t u)
+{
+ return dns_b_putc(b, u >> 24), dns_b_putc(b, u >> 16),
+ dns_b_putc(b, u >> 8), dns_b_putc(b, u >> 0);
+}
+
+static dns_error_t
+dns_b_put(struct dns_buf *b, const void *src, size_t len)
+{
+ size_t n = DNS_PP_MIN((size_t)(b->pe - b->p), len);
+
+ memcpy(b->p, src, n);
+ b->p += n;
+
+ if (n < len)
+ return dns_b_setoverflow(b, len - n, DNS_ENOBUFS);
+
+ return 0;
+}
+
+static dns_error_t
+dns_b_puts(struct dns_buf *b, const void *src)
+{
+ return dns_b_put(b, src, strlen(src));
+}
+
+DNS_NOTUSED static inline dns_error_t
+dns_b_fmtju(struct dns_buf *b, const uintmax_t u, const unsigned width)
+{
+ size_t digits, padding, overflow;
+ uintmax_t r;
+ unsigned char *tp, *te, tc;
+
+ digits = 0;
+ r = u;
+ do {
+ digits++;
+ r /= 10;
+ } while (r);
+
+ padding = width - DNS_PP_MIN(digits, width);
+ overflow = (digits + padding) - DNS_PP_MIN((size_t)(b->pe - b->p), (digits + padding));
+
+ while (padding--) {
+ dns_b_putc(b, '0');
+ }
+
+ digits = 0;
+ tp = b->p;
+ r = u;
+ do {
+ if (overflow < ++digits)
+ dns_b_putc(b, '0' + (r % 10));
+ r /= 10;
+ } while (r);
+
+ te = b->p;
+ while (tp < te) {
+ tc = *--te;
+ *te = *tp;
+ *tp++ = tc;
+ }
+
+ return b->error;
+}
+
+static void
+dns_b_popc(struct dns_buf *b)
+{
+ if (b->overflow && !--b->overflow)
+ b->error = 0;
+ if (b->p > b->base)
+ b->p--;
+}
+
+static inline const char *
+dns_b_tolstring(struct dns_buf *b, size_t *n)
+{
+ if (b->p < b->pe) {
+ *b->p = '\0';
+ *n = b->p - b->base;
+
+ return (const char *)b->base;
+ } else if (b->p > b->base) {
+ if (b->p[-1] != '\0') {
+ dns_b_setoverflow(b, 1, DNS_ENOBUFS);
+ b->p[-1] = '\0';
+ }
+ *n = &b->p[-1] - b->base;
+
+ return (const char *)b->base;
+ } else {
+ *n = 0;
+
+ return "";
+ }
+}
+
+static inline const char *
+dns_b_tostring(struct dns_buf *b)
+{
+ size_t n;
+ return dns_b_tolstring(b, &n);
+}
+
+static inline size_t
+dns_b_strlen(struct dns_buf *b)
+{
+ size_t n;
+ dns_b_tolstring(b, &n);
+ return n;
+}
+
+static inline size_t
+dns_b_strllen(struct dns_buf *b)
+{
+ size_t n = dns_b_strlen(b);
+ return n + b->overflow;
+}
+
+DNS_NOTUSED static const struct dns_buf *
+dns_b_from(const struct dns_buf *b, const void *src, size_t n)
+{
+ *(struct dns_buf *)b = (struct dns_buf)DNS_B_FROM(src, n);
+
+ return b;
+}
+
+static inline int
+dns_b_getc(const struct dns_buf *_b, const int eof)
+{
+ struct dns_buf *b = (struct dns_buf *)_b;
+
+ if (!(b->p < b->pe))
+ return dns_b_setoverflow(b, 1, DNS_EILLEGAL), eof;
+
+ return *b->p++;
+}
+
+static inline intmax_t
+dns_b_get16(const struct dns_buf *b, const intmax_t eof)
+{
+ intmax_t n;
+
+ n = (dns_b_getc(b, 0) << 8);
+ n |= (dns_b_getc(b, 0) << 0);
+
+ return (!b->overflow)? n : eof;
+}
+
+DNS_NOTUSED static inline intmax_t
+dns_b_get32(const struct dns_buf *b, const intmax_t eof)
+{
+ intmax_t n;
+
+ n = (dns_b_get16(b, 0) << 16);
+ n |= (dns_b_get16(b, 0) << 0);
+
+ return (!b->overflow)? n : eof;
+}
+
+static inline dns_error_t
+dns_b_move(struct dns_buf *dst, const struct dns_buf *_src, size_t n)
+{
+ struct dns_buf *src = (struct dns_buf *)_src;
+ size_t src_n = DNS_PP_MIN((size_t)(src->pe - src->p), n);
+ size_t src_r = n - src_n;
+
+ dns_b_put(dst, src->p, src_n);
+ src->p += src_n;
+
+ if (src_r)
+ return dns_b_setoverflow(src, src_r, DNS_EILLEGAL);
+
+ return dst->error;
+}
+
+/*
+ * T I M E R O U T I N E S
+ *
+ * Most functions still rely on the older time routines defined in the
+ * utility routines section, above.
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_TIME_C(n) UINT64_C(n)
+#define DNS_TIME_INF (~DNS_TIME_C(0))
+
+typedef uint64_t dns_time_t;
+typedef dns_time_t dns_microseconds_t;
+
+static dns_error_t dns_time_add(dns_time_t *r, dns_time_t a, dns_time_t b) {
+ int error;
+ DNS_CHECK_OVERFLOW(&error, r, dns_add_overflow, a, b, DNS_TIME_INF);
+ return error;
+}
+
+static dns_error_t dns_time_mul(dns_time_t *r, dns_time_t a, dns_time_t b) {
+ int error;
+ DNS_CHECK_OVERFLOW(&error, r, dns_mul_overflow, a, b, DNS_TIME_INF);
+ return error;
+}
+
+static dns_error_t dns_time_diff(dns_time_t *r, dns_time_t a, dns_time_t b) {
+ if (a < b) {
+ *r = DNS_TIME_C(0);
+ return ERANGE;
+ } else {
+ *r = a - b;
+ return 0;
+ }
+}
+
+static dns_microseconds_t dns_ts2us(const struct timespec *ts, _Bool rup) {
+ if (ts) {
+ dns_time_t sec = DNS_PP_MAX(0, ts->tv_sec);
+ dns_time_t nsec = DNS_PP_MAX(0, ts->tv_nsec);
+ dns_time_t usec = nsec / 1000;
+ dns_microseconds_t r;
+
+ if (rup && nsec % 1000 > 0)
+ usec++;
+ dns_time_mul(&r, sec, DNS_TIME_C(1000000));
+ dns_time_add(&r, r, usec);
+
+ return r;
+ } else {
+ return DNS_TIME_INF;
+ }
+} /* dns_ts2us() */
+
+static struct timespec *dns_tv2ts(struct timespec *ts, const struct timeval *tv) {
+ if (tv) {
+ ts->tv_sec = tv->tv_sec;
+ ts->tv_nsec = tv->tv_usec * 1000;
+
+ return ts;
+ } else {
+ return NULL;
+ }
+} /* dns_tv2ts() */
+
+static size_t dns_utime_print(void *_dst, size_t lim, dns_microseconds_t us) {
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+
+ dns_b_fmtju(&dst, us / 1000000, 1);
+ dns_b_putc(&dst, '.');
+ dns_b_fmtju(&dst, us % 1000000, 6);
+
+ return dns_b_strllen(&dst);
+} /* dns_utime_print() */
+
+/*
+ * P A C K E T R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+unsigned dns_p_count(struct dns_packet *P, enum dns_section section) {
+ unsigned count;
+
+ switch (section) {
+ case DNS_S_QD:
+ return ntohs(dns_header(P)->qdcount);
+ case DNS_S_AN:
+ return ntohs(dns_header(P)->ancount);
+ case DNS_S_NS:
+ return ntohs(dns_header(P)->nscount);
+ case DNS_S_AR:
+ return ntohs(dns_header(P)->arcount);
+ default:
+ count = 0;
+
+ if (section & DNS_S_QD)
+ count += ntohs(dns_header(P)->qdcount);
+ if (section & DNS_S_AN)
+ count += ntohs(dns_header(P)->ancount);
+ if (section & DNS_S_NS)
+ count += ntohs(dns_header(P)->nscount);
+ if (section & DNS_S_AR)
+ count += ntohs(dns_header(P)->arcount);
+
+ return count;
+ }
+} /* dns_p_count() */
+
+
+struct dns_packet *dns_p_init(struct dns_packet *P, size_t size) {
+ if (!P)
+ return 0;
+
+ assert(size >= offsetof(struct dns_packet, data) + 12);
+
+ memset(P, 0, sizeof *P);
+ P->size = size - offsetof(struct dns_packet, data);
+ P->end = 12;
+
+ memset(P->data, '\0', 12);
+
+ return P;
+} /* dns_p_init() */
+
+
+static struct dns_packet *dns_p_reset(struct dns_packet *P) {
+ return dns_p_init(P, offsetof(struct dns_packet, data) + P->size);
+} /* dns_p_reset() */
+
+
+static unsigned short dns_p_qend(struct dns_packet *P) {
+ unsigned short qend = 12;
+ unsigned i, count = dns_p_count(P, DNS_S_QD);
+
+ for (i = 0; i < count && qend < P->end; i++) {
+ if (P->end == (qend = dns_d_skip(qend, P)))
+ goto invalid;
+
+ if (P->end - qend < 4)
+ goto invalid;
+
+ qend += 4;
+ }
+
+ return DNS_PP_MIN(qend, P->end);
+invalid:
+ return P->end;
+} /* dns_p_qend() */
+
+
+struct dns_packet *dns_p_make(size_t len, int *error) {
+ struct dns_packet *P;
+ size_t size = dns_p_calcsize(len);
+
+ if (!(P = dns_p_init(malloc(size), size)))
+ *error = dns_syerr();
+
+ return P;
+} /* dns_p_make() */
+
+
+static void dns_p_free(struct dns_packet *P) {
+ free(P);
+} /* dns_p_free() */
+
+
+/* convience routine to free any existing packet before storing new packet */
+static struct dns_packet *dns_p_setptr(struct dns_packet **dst, struct dns_packet *src) {
+ dns_p_free(*dst);
+
+ *dst = src;
+
+ return src;
+} /* dns_p_setptr() */
+
+
+static struct dns_packet *dns_p_movptr(struct dns_packet **dst, struct dns_packet **src) {
+ dns_p_setptr(dst, *src);
+
+ *src = NULL;
+
+ return *dst;
+} /* dns_p_movptr() */
+
+
+int dns_p_grow(struct dns_packet **P) {
+ struct dns_packet *tmp;
+ size_t size;
+ int error;
+
+ if (!*P) {
+ if (!(*P = dns_p_make(DNS_P_QBUFSIZ, &error)))
+ return error;
+
+ return 0;
+ }
+
+ size = dns_p_sizeof(*P);
+ size |= size >> 1;
+ size |= size >> 2;
+ size |= size >> 4;
+ size |= size >> 8;
+ size++;
+
+ if (size > 65536)
+ return DNS_ENOBUFS;
+
+ if (!(tmp = realloc(*P, dns_p_calcsize(size))))
+ return dns_syerr();
+
+ tmp->size = size;
+ *P = tmp;
+
+ return 0;
+} /* dns_p_grow() */
+
+
+struct dns_packet *dns_p_copy(struct dns_packet *P, const struct dns_packet *P0) {
+ if (!P)
+ return 0;
+
+ P->end = DNS_PP_MIN(P->size, P0->end);
+
+ memcpy(P->data, P0->data, P->end);
+
+ return P;
+} /* dns_p_copy() */
+
+
+struct dns_packet *dns_p_merge(struct dns_packet *A, enum dns_section Amask, struct dns_packet *B, enum dns_section Bmask, int *error_) {
+ size_t bufsiz = DNS_PP_MIN(65535, ((A)? A->end : 0) + ((B)? B->end : 0));
+ struct dns_packet *M;
+ enum dns_section section;
+ struct dns_rr rr, mr;
+ int error, copy;
+
+ if (!A && B) {
+ A = B;
+ Amask = Bmask;
+ B = 0;
+ }
+
+merge:
+ if (!(M = dns_p_make(bufsiz, &error)))
+ goto error;
+
+ for (section = DNS_S_QD; (DNS_S_ALL & section); section <<= 1) {
+ if (A && (section & Amask)) {
+ dns_rr_foreach(&rr, A, .section = section) {
+ if ((error = dns_rr_copy(M, &rr, A)))
+ goto error;
+ }
+ }
+
+ if (B && (section & Bmask)) {
+ dns_rr_foreach(&rr, B, .section = section) {
+ copy = 1;
+
+ dns_rr_foreach(&mr, M, .type = rr.type, .section = DNS_S_ALL) {
+ if (!(copy = dns_rr_cmp(&rr, B, &mr, M)))
+ break;
+ }
+
+ if (copy && (error = dns_rr_copy(M, &rr, B)))
+ goto error;
+ }
+ }
+ }
+
+ return M;
+error:
+ dns_p_setptr(&M, NULL);
+
+ if (error == DNS_ENOBUFS && bufsiz < 65535) {
+ bufsiz = DNS_PP_MIN(65535, bufsiz * 2);
+
+ goto merge;
+ }
+
+ *error_ = error;
+
+ return 0;
+} /* dns_p_merge() */
+
+
+static unsigned short dns_l_skip(unsigned short, const unsigned char *, size_t);
+
+void dns_p_dictadd(struct dns_packet *P, unsigned short dn) {
+ unsigned short lp, lptr, i;
+
+ lp = dn;
+
+ while (lp < P->end) {
+ if (0xc0 == (0xc0 & P->data[lp]) && P->end - lp >= 2 && lp != dn) {
+ lptr = ((0x3f & P->data[lp + 0]) << 8)
+ | ((0xff & P->data[lp + 1]) << 0);
+
+ for (i = 0; i < lengthof(P->dict) && P->dict[i]; i++) {
+ if (P->dict[i] == lptr) {
+ P->dict[i] = dn;
+
+ return;
+ }
+ }
+ }
+
+ lp = dns_l_skip(lp, P->data, P->end);
+ }
+
+ for (i = 0; i < lengthof(P->dict); i++) {
+ if (!P->dict[i]) {
+ P->dict[i] = dn;
+
+ break;
+ }
+ }
+} /* dns_p_dictadd() */
+
+
+int dns_p_push(struct dns_packet *P, enum dns_section section, const void *dn, size_t dnlen, enum dns_type type, enum dns_class class, unsigned ttl, const void *any) {
+ size_t end = P->end;
+ int error;
+
+ if ((error = dns_d_push(P, dn, dnlen)))
+ goto error;
+
+ if (P->size - P->end < 4)
+ goto nobufs;
+
+ P->data[P->end++] = 0xff & (type >> 8);
+ P->data[P->end++] = 0xff & (type >> 0);
+
+ P->data[P->end++] = 0xff & (class >> 8);
+ P->data[P->end++] = 0xff & (class >> 0);
+
+ if (section == DNS_S_QD)
+ goto update;
+
+ if (P->size - P->end < 6)
+ goto nobufs;
+
+ if (type != DNS_T_OPT)
+ ttl = DNS_PP_MIN(ttl, 0x7fffffffU);
+ P->data[P->end++] = ttl >> 24;
+ P->data[P->end++] = ttl >> 16;
+ P->data[P->end++] = ttl >> 8;
+ P->data[P->end++] = ttl >> 0;
+
+ if ((error = dns_any_push(P, (union dns_any *)any, type)))
+ goto error;
+
+update:
+ switch (section) {
+ case DNS_S_QD:
+ if (dns_p_count(P, DNS_S_AN|DNS_S_NS|DNS_S_AR))
+ goto order;
+
+ if (!P->memo.qd.base && (error = dns_p_study(P)))
+ goto error;
+
+ dns_header(P)->qdcount = htons(ntohs(dns_header(P)->qdcount) + 1);
+
+ P->memo.qd.end = P->end;
+ P->memo.an.base = P->end;
+ P->memo.an.end = P->end;
+ P->memo.ns.base = P->end;
+ P->memo.ns.end = P->end;
+ P->memo.ar.base = P->end;
+ P->memo.ar.end = P->end;
+
+ break;
+ case DNS_S_AN:
+ if (dns_p_count(P, DNS_S_NS|DNS_S_AR))
+ goto order;
+
+ if (!P->memo.an.base && (error = dns_p_study(P)))
+ goto error;
+
+ dns_header(P)->ancount = htons(ntohs(dns_header(P)->ancount) + 1);
+
+ P->memo.an.end = P->end;
+ P->memo.ns.base = P->end;
+ P->memo.ns.end = P->end;
+ P->memo.ar.base = P->end;
+ P->memo.ar.end = P->end;
+
+ break;
+ case DNS_S_NS:
+ if (dns_p_count(P, DNS_S_AR))
+ goto order;
+
+ if (!P->memo.ns.base && (error = dns_p_study(P)))
+ goto error;
+
+ dns_header(P)->nscount = htons(ntohs(dns_header(P)->nscount) + 1);
+
+ P->memo.ns.end = P->end;
+ P->memo.ar.base = P->end;
+ P->memo.ar.end = P->end;
+
+ break;
+ case DNS_S_AR:
+ if (!P->memo.ar.base && (error = dns_p_study(P)))
+ goto error;
+
+ dns_header(P)->arcount = htons(ntohs(dns_header(P)->arcount) + 1);
+
+ P->memo.ar.end = P->end;
+
+ if (type == DNS_T_OPT && !P->memo.opt.p) {
+ P->memo.opt.p = end;
+ P->memo.opt.maxudp = class;
+ P->memo.opt.ttl = ttl;
+ }
+
+ break;
+ default:
+ error = DNS_ESECTION;
+
+ goto error;
+ } /* switch() */
+
+ return 0;
+nobufs:
+ error = DNS_ENOBUFS;
+
+ goto error;
+order:
+ error = DNS_EORDER;
+
+ goto error;
+error:
+ P->end = end;
+
+ return error;
+} /* dns_p_push() */
+
+#define DNS_SM_RESTORE do { pc = state->pc; error = state->error; } while (0)
+#define DNS_SM_SAVE do { state->error = error; state->pc = pc; } while (0)
+
+struct dns_p_lines_i {
+ int pc;
+ enum dns_section section;
+ struct dns_rr rr;
+ int error;
+};
+
+static size_t dns_p_lines_fmt(void *dst, size_t lim, dns_error_t *_error, const char *fmt, ...) {
+ va_list ap;
+ int error = 0, n;
+
+ va_start(ap, fmt);
+ if ((n = vsnprintf(dst, lim, fmt, ap)) < 0)
+ error = errno;
+ va_end(ap);
+
+ *_error = error;
+ return DNS_PP_MAX(n, 0);
+} /* dns_p_lines_fmt() */
+
+#define DNS_P_LINE(...) \
+ do { \
+ len = dns_p_lines_fmt(dst, lim, &error, __VA_ARGS__); \
+ if (len == 0 && error) \
+ goto error; \
+ DNS_SM_YIELD(len); \
+ } while (0)
+
+static size_t dns_p_lines(void *dst, size_t lim, dns_error_t *_error, struct dns_packet *P, struct dns_rr_i *I, struct dns_p_lines_i *state) {
+ int error, pc;
+ size_t len;
+
+ *_error = 0;
+
+ DNS_SM_ENTER;
+
+ DNS_P_LINE(";; [HEADER]\n");
+ DNS_P_LINE(";; qid : %d\n", ntohs(dns_header(P)->qid));
+ DNS_P_LINE(";; qr : %s(%d)\n", (dns_header(P)->qr)? "RESPONSE" : "QUERY", dns_header(P)->qr);
+ DNS_P_LINE(";; opcode : %s(%d)\n", dns_stropcode(dns_header(P)->opcode), dns_header(P)->opcode);
+ DNS_P_LINE(";; aa : %s(%d)\n", (dns_header(P)->aa)? "AUTHORITATIVE" : "NON-AUTHORITATIVE", dns_header(P)->aa);
+ DNS_P_LINE(";; tc : %s(%d)\n", (dns_header(P)->tc)? "TRUNCATED" : "NOT-TRUNCATED", dns_header(P)->tc);
+ DNS_P_LINE(";; rd : %s(%d)\n", (dns_header(P)->rd)? "RECURSION-DESIRED" : "RECURSION-NOT-DESIRED", dns_header(P)->rd);
+ DNS_P_LINE(";; ra : %s(%d)\n", (dns_header(P)->ra)? "RECURSION-ALLOWED" : "RECURSION-NOT-ALLOWED", dns_header(P)->ra);
+ DNS_P_LINE(";; rcode : %s(%d)\n", dns_strrcode(dns_p_rcode(P)), dns_p_rcode(P));
+
+ while (dns_rr_grep(&state->rr, 1, I, P, &error)) {
+ if (state->section != state->rr.section) {
+ DNS_P_LINE("\n");
+ DNS_P_LINE(";; [%s:%d]\n", dns_strsection(state->rr.section), dns_p_count(P, state->rr.section));
+ }
+
+ if (!(len = dns_rr_print(dst, lim, &state->rr, P, &error)))
+ goto error;
+ dns_strlcat(dst, "\n", lim);
+ DNS_SM_YIELD(len + 1);
+
+ state->section = state->rr.section;
+ }
+
+ if (error)
+ goto error;
+
+ DNS_SM_EXIT;
+error:
+ for (;;) {
+ *_error = error;
+ DNS_SM_YIELD(0);
+ }
+
+ DNS_SM_LEAVE;
+
+ *_error = 0;
+ return 0;
+} /* dns_p_lines() */
+
+#undef DNS_P_LINE
+#undef DNS_SM_SAVE
+#undef DNS_SM_RESTORE
+
+static void dns_p_dump3(struct dns_packet *P, struct dns_rr_i *I, FILE *fp) {
+ struct dns_p_lines_i lines = { 0 };
+ char line[sizeof (union dns_any) * 2];
+ size_t len;
+ int error;
+
+ while ((len = dns_p_lines(line, sizeof line, &error, P, I, &lines))) {
+ if (len < sizeof line) {
+ fwrite(line, 1, len, fp);
+ } else {
+ fwrite(line, 1, sizeof line - 1, fp);
+ fputc('\n', fp);
+ }
+ }
+} /* dns_p_dump3() */
+
+
+void dns_p_dump(struct dns_packet *P, FILE *fp) {
+ dns_p_dump3(P, dns_rr_i_new(P, .section = 0), fp);
+} /* dns_p_dump() */
+
+
+static void dns_s_unstudy(struct dns_s_memo *m)
+ { m->base = 0; m->end = 0; }
+
+static void dns_m_unstudy(struct dns_p_memo *m) {
+ dns_s_unstudy(&m->qd);
+ dns_s_unstudy(&m->an);
+ dns_s_unstudy(&m->ns);
+ dns_s_unstudy(&m->ar);
+ m->opt.p = 0;
+ m->opt.maxudp = 0;
+ m->opt.ttl = 0;
+} /* dns_m_unstudy() */
+
+static int dns_s_study(struct dns_s_memo *m, enum dns_section section, unsigned short base, struct dns_packet *P) {
+ unsigned short count, rp;
+
+ count = dns_p_count(P, section);
+
+ for (rp = base; count && rp < P->end; count--)
+ rp = dns_rr_skip(rp, P);
+
+ m->base = base;
+ m->end = rp;
+
+ return 0;
+} /* dns_s_study() */
+
+static int dns_m_study(struct dns_p_memo *m, struct dns_packet *P) {
+ struct dns_rr rr;
+ int error;
+
+ if ((error = dns_s_study(&m->qd, DNS_S_QD, 12, P)))
+ goto error;
+ if ((error = dns_s_study(&m->an, DNS_S_AN, m->qd.end, P)))
+ goto error;
+ if ((error = dns_s_study(&m->ns, DNS_S_NS, m->an.end, P)))
+ goto error;
+ if ((error = dns_s_study(&m->ar, DNS_S_AR, m->ns.end, P)))
+ goto error;
+
+ m->opt.p = 0;
+ m->opt.maxudp = 0;
+ m->opt.ttl = 0;
+ dns_rr_foreach(&rr, P, .type = DNS_T_OPT, .section = DNS_S_AR) {
+ m->opt.p = rr.dn.p;
+ m->opt.maxudp = rr.class;
+ m->opt.ttl = rr.ttl;
+ break;
+ }
+
+ return 0;
+error:
+ dns_m_unstudy(m);
+
+ return error;
+} /* dns_m_study() */
+
+int dns_p_study(struct dns_packet *P) {
+ return dns_m_study(&P->memo, P);
+} /* dns_p_study() */
+
+
+enum dns_rcode dns_p_rcode(struct dns_packet *P) {
+ return 0xfff & ((P->memo.opt.ttl >> 20) | dns_header(P)->rcode);
+} /* dns_p_rcode() */
+
+
+/*
+ * Q U E R Y P A C K E T R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_Q_RD 0x1 /* recursion desired */
+#define DNS_Q_EDNS0 0x2 /* include OPT RR */
+
+static dns_error_t
+dns_q_make2(struct dns_packet **_Q, const char *qname, size_t qlen, enum dns_type qtype, enum dns_class qclass, int qflags)
+{
+ struct dns_packet *Q = NULL;
+ int error;
+
+ if (dns_p_movptr(&Q, _Q)) {
+ dns_p_reset(Q);
+ } else if (!(Q = dns_p_make(DNS_P_QBUFSIZ, &error))) {
+ goto error;
+ }
+
+ if ((error = dns_p_push(Q, DNS_S_QD, qname, qlen, qtype, qclass, 0, 0)))
+ goto error;
+
+ dns_header(Q)->rd = !!(qflags & DNS_Q_RD);
+
+ if (qflags & DNS_Q_EDNS0) {
+ struct dns_opt opt = DNS_OPT_INIT(&opt);
+
+ opt.version = 0; /* RFC 6891 version */
+ opt.maxudp = 4096;
+
+ if ((error = dns_p_push(Q, DNS_S_AR, ".", 1, DNS_T_OPT, dns_opt_class(&opt), dns_opt_ttl(&opt), &opt)))
+ goto error;
+ }
+
+ *_Q = Q;
+
+ return 0;
+error:
+ dns_p_free(Q);
+
+ return error;
+}
+
+static dns_error_t
+dns_q_make(struct dns_packet **Q, const char *qname, enum dns_type qtype, enum dns_class qclass, int qflags)
+{
+ return dns_q_make2(Q, qname, strlen(qname), qtype, qclass, qflags);
+}
+
+static dns_error_t
+dns_q_remake(struct dns_packet **Q, int qflags)
+{
+ char qname[DNS_D_MAXNAME + 1];
+ size_t qlen;
+ struct dns_rr rr;
+ int error;
+
+ assert(Q && *Q);
+ if ((error = dns_rr_parse(&rr, 12, *Q)))
+ return error;
+ if (!(qlen = dns_d_expand(qname, sizeof qname, rr.dn.p, *Q, &error)))
+ return error;
+ if (qlen >= sizeof qname)
+ return DNS_EILLEGAL;
+ return dns_q_make2(Q, qname, qlen, rr.type, rr.class, qflags);
+}
+
+/*
+ * D O M A I N N A M E R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#ifndef DNS_D_MAXPTRS
+#define DNS_D_MAXPTRS 127 /* Arbitrary; possible, valid depth is something like packet size / 2 + fudge. */
+#endif
+
+static size_t dns_l_expand(unsigned char *dst, size_t lim, unsigned short src, unsigned short *nxt, const unsigned char *data, size_t end) {
+ unsigned short len;
+ unsigned nptrs = 0;
+
+retry:
+ if (src >= end)
+ goto invalid;
+
+ switch (0x03 & (data[src] >> 6)) {
+ case 0x00:
+ len = (0x3f & (data[src++]));
+
+ if (end - src < len)
+ goto invalid;
+
+ if (lim > 0) {
+ memcpy(dst, &data[src], DNS_PP_MIN(lim, len));
+
+ dst[DNS_PP_MIN(lim - 1, len)] = '\0';
+ }
+
+ *nxt = src + len;
+
+ return len;
+ case 0x01:
+ goto invalid;
+ case 0x02:
+ goto invalid;
+ case 0x03:
+ if (++nptrs > DNS_D_MAXPTRS)
+ goto invalid;
+
+ if (end - src < 2)
+ goto invalid;
+
+ src = ((0x3f & data[src + 0]) << 8)
+ | ((0xff & data[src + 1]) << 0);
+
+ goto retry;
+ } /* switch() */
+
+ /* NOT REACHED */
+invalid:
+ *nxt = end;
+
+ return 0;
+} /* dns_l_expand() */
+
+
+static unsigned short dns_l_skip(unsigned short src, const unsigned char *data, size_t end) {
+ unsigned short len;
+
+ if (src >= end)
+ goto invalid;
+
+ switch (0x03 & (data[src] >> 6)) {
+ case 0x00:
+ len = (0x3f & (data[src++]));
+
+ if (end - src < len)
+ goto invalid;
+
+ return (len)? src + len : end;
+ case 0x01:
+ goto invalid;
+ case 0x02:
+ goto invalid;
+ case 0x03:
+ return end;
+ } /* switch() */
+
+ /* NOT REACHED */
+invalid:
+ return end;
+} /* dns_l_skip() */
+
+
+static _Bool dns_d_isanchored(const void *_src, size_t len) {
+ const unsigned char *src = _src;
+ return len > 0 && src[len - 1] == '.';
+} /* dns_d_isanchored() */
+
+
+static size_t dns_d_ndots(const void *_src, size_t len) {
+ const unsigned char *p = _src, *pe = p + len;
+ size_t ndots = 0;
+
+ while ((p = memchr(p, '.', pe - p))) {
+ ndots++;
+ p++;
+ }
+
+ return ndots;
+} /* dns_d_ndots() */
+
+
+static size_t dns_d_trim(void *dst_, size_t lim, const void *src_, size_t len, int flags) {
+ unsigned char *dst = dst_;
+ const unsigned char *src = src_;
+ size_t dp = 0, sp = 0;
+ int lc;
+
+ /* trim any leading dot(s) */
+ while (sp < len && src[sp] == '.')
+ sp++;
+
+ for (lc = 0; sp < len; lc = src[sp++]) {
+ /* trim extra dot(s) */
+ if (src[sp] == '.' && lc == '.')
+ continue;
+
+ if (dp < lim)
+ dst[dp] = src[sp];
+
+ dp++;
+ }
+
+ if ((flags & DNS_D_ANCHOR) && lc != '.') {
+ if (dp < lim)
+ dst[dp] = '.';
+
+ dp++;
+ }
+
+ if (lim > 0)
+ dst[DNS_PP_MIN(dp, lim - 1)] = '\0';
+
+ return dp;
+} /* dns_d_trim() */
+
+
+char *dns_d_init(void *dst, size_t lim, const void *src, size_t len, int flags) {
+ if (flags & DNS_D_TRIM) {
+ dns_d_trim(dst, lim, src, len, flags);
+ } if (flags & DNS_D_ANCHOR) {
+ dns_d_anchor(dst, lim, src, len);
+ } else {
+ memmove(dst, src, DNS_PP_MIN(lim, len));
+
+ if (lim > 0)
+ ((char *)dst)[DNS_PP_MIN(len, lim - 1)] = '\0';
+ }
+
+ return dst;
+} /* dns_d_init() */
+
+
+size_t dns_d_anchor(void *dst, size_t lim, const void *src, size_t len) {
+ if (len == 0)
+ return 0;
+
+ memmove(dst, src, DNS_PP_MIN(lim, len));
+
+ if (((const char *)src)[len - 1] != '.') {
+ if (len < lim)
+ ((char *)dst)[len] = '.';
+ len++;
+ }
+
+ if (lim > 0)
+ ((char *)dst)[DNS_PP_MIN(lim - 1, len)] = '\0';
+
+ return len;
+} /* dns_d_anchor() */
+
+
+size_t dns_d_cleave(void *dst, size_t lim, const void *src, size_t len) {
+ const char *dot;
+
+ /* XXX: Skip any leading dot. Handles cleaving root ".". */
+ if (len == 0 || !(dot = memchr((const char *)src + 1, '.', len - 1)))
+ return 0;
+
+ len -= dot - (const char *)src;
+
+ /* XXX: Unless root, skip the label's trailing dot. */
+ if (len > 1) {
+ src = ++dot;
+ len--;
+ } else
+ src = dot;
+
+ memmove(dst, src, DNS_PP_MIN(lim, len));
+
+ if (lim > 0)
+ ((char *)dst)[DNS_PP_MIN(lim - 1, len)] = '\0';
+
+ return len;
+} /* dns_d_cleave() */
+
+
+size_t dns_d_comp(void *dst_, size_t lim, const void *src_, size_t len, struct dns_packet *P, int *error) {
+ struct { unsigned char *b; size_t p, x; } dst, src;
+ unsigned char ch = '.';
+
+ dst.b = dst_;
+ dst.p = 0;
+ dst.x = 1;
+
+ src.b = (unsigned char *)src_;
+ src.p = 0;
+ src.x = 0;
+
+ while (src.x < len) {
+ ch = src.b[src.x];
+
+ if (ch == '.') {
+ if (dst.p < lim)
+ dst.b[dst.p] = (0x3f & (src.x - src.p));
+
+ dst.p = dst.x++;
+ src.p = ++src.x;
+ } else {
+ if (dst.x < lim)
+ dst.b[dst.x] = ch;
+
+ dst.x++;
+ src.x++;
+ }
+ } /* while() */
+
+ if (src.x > src.p) {
+ if (dst.p < lim)
+ dst.b[dst.p] = (0x3f & (src.x - src.p));
+
+ dst.p = dst.x;
+ }
+
+ if (dst.p > 1) {
+ if (dst.p < lim)
+ dst.b[dst.p] = 0x00;
+
+ dst.p++;
+ }
+
+#if 1
+ if (dst.p < lim) {
+ struct { unsigned char label[DNS_D_MAXLABEL + 1]; size_t len; unsigned short p, x, y; } a, b;
+ unsigned i;
+
+ a.p = 0;
+
+ while ((a.len = dns_l_expand(a.label, sizeof a.label, a.p, &a.x, dst.b, lim))) {
+ for (i = 0; i < lengthof(P->dict) && P->dict[i]; i++) {
+ b.p = P->dict[i];
+
+ while ((b.len = dns_l_expand(b.label, sizeof b.label, b.p, &b.x, P->data, P->end))) {
+ a.y = a.x;
+ b.y = b.x;
+
+ while (a.len && b.len && 0 == strcasecmp((char *)a.label, (char *)b.label)) {
+ a.len = dns_l_expand(a.label, sizeof a.label, a.y, &a.y, dst.b, lim);
+ b.len = dns_l_expand(b.label, sizeof b.label, b.y, &b.y, P->data, P->end);
+ }
+
+ if (a.len == 0 && b.len == 0 && b.p <= 0x3fff) {
+ dst.b[a.p++] = 0xc0
+ | (0x3f & (b.p >> 8));
+ dst.b[a.p++] = (0xff & (b.p >> 0));
+
+ /* silence static analyzers */
+ dns_assume(a.p > 0);
+
+ return a.p;
+ }
+
+ b.p = b.x;
+ } /* while() */
+ } /* for() */
+
+ a.p = a.x;
+ } /* while() */
+ } /* if () */
+#endif
+
+ if (!dst.p)
+ *error = DNS_EILLEGAL;
+
+ return dst.p;
+} /* dns_d_comp() */
+
+
+unsigned short dns_d_skip(unsigned short src, struct dns_packet *P) {
+ unsigned short len;
+
+ while (src < P->end) {
+ switch (0x03 & (P->data[src] >> 6)) {
+ case 0x00: /* FOLLOWS */
+ len = (0x3f & P->data[src++]);
+
+ if (0 == len) {
+/* success ==> */ return src;
+ } else if (P->end - src > len) {
+ src += len;
+
+ break;
+ } else
+ goto invalid;
+
+ /* NOT REACHED */
+ case 0x01: /* RESERVED */
+ goto invalid;
+ case 0x02: /* RESERVED */
+ goto invalid;
+ case 0x03: /* POINTER */
+ if (P->end - src < 2)
+ goto invalid;
+
+ src += 2;
+
+/* success ==> */ return src;
+ } /* switch() */
+ } /* while() */
+
+invalid:
+ return P->end;
+} /* dns_d_skip() */
+
+
+#include <stdio.h>
+
+size_t dns_d_expand(void *dst, size_t lim, unsigned short src, struct dns_packet *P, int *error) {
+ size_t dstp = 0;
+ unsigned nptrs = 0;
+ unsigned char len;
+
+ while (src < P->end) {
+ switch ((0x03 & (P->data[src] >> 6))) {
+ case 0x00: /* FOLLOWS */
+ len = (0x3f & P->data[src]);
+
+ if (0 == len) {
+ if (dstp == 0) {
+ if (dstp < lim)
+ ((unsigned char *)dst)[dstp] = '.';
+
+ dstp++;
+ }
+
+ /* NUL terminate */
+ if (lim > 0)
+ ((unsigned char *)dst)[DNS_PP_MIN(dstp, lim - 1)] = '\0';
+
+/* success ==> */ return dstp;
+ }
+
+ src++;
+
+ if (P->end - src < len)
+ goto toolong;
+
+ if (dstp < lim)
+ memcpy(&((unsigned char *)dst)[dstp], &P->data[src], DNS_PP_MIN(len, lim - dstp));
+
+ src += len;
+ dstp += len;
+
+ if (dstp < lim)
+ ((unsigned char *)dst)[dstp] = '.';
+
+ dstp++;
+
+ nptrs = 0;
+
+ continue;
+ case 0x01: /* RESERVED */
+ goto reserved;
+ case 0x02: /* RESERVED */
+ goto reserved;
+ case 0x03: /* POINTER */
+ if (++nptrs > DNS_D_MAXPTRS)
+ goto toolong;
+
+ if (P->end - src < 2)
+ goto toolong;
+
+ src = ((0x3f & P->data[src + 0]) << 8)
+ | ((0xff & P->data[src + 1]) << 0);
+
+ continue;
+ } /* switch() */
+ } /* while() */
+
+toolong:
+ *error = DNS_EILLEGAL;
+
+ if (lim > 0)
+ ((unsigned char *)dst)[DNS_PP_MIN(dstp, lim - 1)] = '\0';
+
+ return 0;
+reserved:
+ *error = DNS_EILLEGAL;
+
+ if (lim > 0)
+ ((unsigned char *)dst)[DNS_PP_MIN(dstp, lim - 1)] = '\0';
+
+ return 0;
+} /* dns_d_expand() */
+
+
+int dns_d_push(struct dns_packet *P, const void *dn, size_t len) {
+ size_t lim = P->size - P->end;
+ unsigned dp = P->end;
+ int error = DNS_EILLEGAL; /* silence compiler */
+
+ len = dns_d_comp(&P->data[dp], lim, dn, len, P, &error);
+
+ if (len == 0)
+ return error;
+ if (len > lim)
+ return DNS_ENOBUFS;
+
+ P->end += len;
+
+ dns_p_dictadd(P, dp);
+
+ return 0;
+} /* dns_d_push() */
+
+
+size_t dns_d_cname(void *dst, size_t lim, const void *dn, size_t len, struct dns_packet *P, int *error_) {
+ char host[DNS_D_MAXNAME + 1];
+ struct dns_rr_i i;
+ struct dns_rr rr;
+ unsigned depth;
+ int error;
+
+ if (sizeof host <= dns_d_anchor(host, sizeof host, dn, len))
+ { error = ENAMETOOLONG; goto error; }
+
+ for (depth = 0; depth < 7; depth++) {
+ dns_rr_i_init(memset(&i, 0, sizeof i), P);
+
+ i.section = DNS_S_ALL & ~DNS_S_QD;
+ i.name = host;
+ i.type = DNS_T_CNAME;
+
+ if (!dns_rr_grep(&rr, 1, &i, P, &error))
+ break;
+
+ if ((error = dns_cname_parse((struct dns_cname *)host, &rr, P)))
+ goto error;
+ }
+
+ return dns_strlcpy(dst, host, lim);
+error:
+ *error_ = error;
+
+ return 0;
+} /* dns_d_cname() */
+
+
+/*
+ * R E S O U R C E R E C O R D R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+int dns_rr_copy(struct dns_packet *P, struct dns_rr *rr, struct dns_packet *Q) {
+ unsigned char dn[DNS_D_MAXNAME + 1];
+ union dns_any any;
+ size_t len;
+ int error;
+
+ if (!(len = dns_d_expand(dn, sizeof dn, rr->dn.p, Q, &error)))
+ return error;
+ else if (len >= sizeof dn)
+ return DNS_EILLEGAL;
+
+ if (rr->section != DNS_S_QD && (error = dns_any_parse(dns_any_init(&any, sizeof any), rr, Q)))
+ return error;
+
+ return dns_p_push(P, rr->section, dn, len, rr->type, rr->class, rr->ttl, &any);
+} /* dns_rr_copy() */
+
+
+int dns_rr_parse(struct dns_rr *rr, unsigned short src, struct dns_packet *P) {
+ unsigned short p = src;
+
+ if (src >= P->end)
+ goto invalid;
+
+ rr->dn.p = p;
+ rr->dn.len = (p = dns_d_skip(p, P)) - rr->dn.p;
+
+ if (P->end - p < 4)
+ goto invalid;
+
+ rr->type = ((0xff & P->data[p + 0]) << 8)
+ | ((0xff & P->data[p + 1]) << 0);
+
+ rr->class = ((0xff & P->data[p + 2]) << 8)
+ | ((0xff & P->data[p + 3]) << 0);
+
+ p += 4;
+
+ if (src < dns_p_qend(P)) {
+ rr->section = DNS_S_QUESTION;
+
+ rr->ttl = 0;
+ rr->rd.p = 0;
+ rr->rd.len = 0;
+
+ return 0;
+ }
+
+ if (P->end - p < 4)
+ goto invalid;
+
+ rr->ttl = ((0xff & P->data[p + 0]) << 24)
+ | ((0xff & P->data[p + 1]) << 16)
+ | ((0xff & P->data[p + 2]) << 8)
+ | ((0xff & P->data[p + 3]) << 0);
+ if (rr->type != DNS_T_OPT)
+ rr->ttl = DNS_PP_MIN(rr->ttl, 0x7fffffffU);
+
+ p += 4;
+
+ if (P->end - p < 2)
+ goto invalid;
+
+ rr->rd.len = ((0xff & P->data[p + 0]) << 8)
+ | ((0xff & P->data[p + 1]) << 0);
+ rr->rd.p = p + 2;
+
+ p += 2;
+
+ if (P->end - p < rr->rd.len)
+ goto invalid;
+
+ return 0;
+invalid:
+ return DNS_EILLEGAL;
+} /* dns_rr_parse() */
+
+
+static unsigned short dns_rr_len(const unsigned short src, struct dns_packet *P) {
+ unsigned short rp, rdlen;
+
+ rp = dns_d_skip(src, P);
+
+ if (P->end - rp < 4)
+ return P->end - src;
+
+ rp += 4; /* TYPE, CLASS */
+
+ if (rp <= dns_p_qend(P))
+ return rp - src;
+
+ if (P->end - rp < 6)
+ return P->end - src;
+
+ rp += 6; /* TTL, RDLEN */
+
+ rdlen = ((0xff & P->data[rp - 2]) << 8)
+ | ((0xff & P->data[rp - 1]) << 0);
+
+ if (P->end - rp < rdlen)
+ return P->end - src;
+
+ rp += rdlen;
+
+ return rp - src;
+} /* dns_rr_len() */
+
+
+unsigned short dns_rr_skip(unsigned short src, struct dns_packet *P) {
+ return src + dns_rr_len(src, P);
+} /* dns_rr_skip() */
+
+
+static enum dns_section dns_rr_section(unsigned short src, struct dns_packet *P) {
+ enum dns_section section;
+ unsigned count, index;
+ unsigned short rp;
+
+ if (src >= P->memo.qd.base && src < P->memo.qd.end)
+ return DNS_S_QD;
+ if (src >= P->memo.an.base && src < P->memo.an.end)
+ return DNS_S_AN;
+ if (src >= P->memo.ns.base && src < P->memo.ns.end)
+ return DNS_S_NS;
+ if (src >= P->memo.ar.base && src < P->memo.ar.end)
+ return DNS_S_AR;
+
+ /* NOTE: Possibly bad memoization. Try it the hard-way. */
+
+ for (rp = 12, index = 0; rp < src && rp < P->end; index++)
+ rp = dns_rr_skip(rp, P);
+
+ section = DNS_S_QD;
+ count = dns_p_count(P, section);
+
+ while (index >= count && section <= DNS_S_AR) {
+ section <<= 1;
+ count += dns_p_count(P, section);
+ }
+
+ return DNS_S_ALL & section;
+} /* dns_rr_section() */
+
+
+static enum dns_type dns_rr_type(unsigned short src, struct dns_packet *P) {
+ struct dns_rr rr;
+ int error;
+
+ if ((error = dns_rr_parse(&rr, src, P)))
+ return 0;
+
+ return rr.type;
+} /* dns_rr_type() */
+
+
+int dns_rr_cmp(struct dns_rr *r0, struct dns_packet *P0, struct dns_rr *r1, struct dns_packet *P1) {
+ char host0[DNS_D_MAXNAME + 1], host1[DNS_D_MAXNAME + 1];
+ union dns_any any0, any1;
+ int cmp, error;
+ size_t len;
+
+ if ((cmp = r0->type - r1->type))
+ return cmp;
+
+ if ((cmp = r0->class - r1->class))
+ return cmp;
+
+ /*
+ * FIXME: Do label-by-label comparison to handle illegally long names?
+ */
+
+ if (!(len = dns_d_expand(host0, sizeof host0, r0->dn.p, P0, &error))
+ || len >= sizeof host0)
+ return -1;
+
+ if (!(len = dns_d_expand(host1, sizeof host1, r1->dn.p, P1, &error))
+ || len >= sizeof host1)
+ return 1;
+
+ if ((cmp = strcasecmp(host0, host1)))
+ return cmp;
+
+ if (DNS_S_QD & (r0->section | r1->section)) {
+ if (r0->section == r1->section)
+ return 0;
+
+ return (r0->section == DNS_S_QD)? -1 : 1;
+ }
+
+ if ((error = dns_any_parse(&any0, r0, P0)))
+ return -1;
+
+ if ((error = dns_any_parse(&any1, r1, P1)))
+ return 1;
+
+ return dns_any_cmp(&any0, r0->type, &any1, r1->type);
+} /* dns_rr_cmp() */
+
+
+static _Bool dns_rr_exists(struct dns_rr *rr0, struct dns_packet *P0, struct dns_packet *P1) {
+ struct dns_rr rr1;
+
+ dns_rr_foreach(&rr1, P1, .section = rr0->section, .type = rr0->type) {
+ if (0 == dns_rr_cmp(rr0, P0, &rr1, P1))
+ return 1;
+ }
+
+ return 0;
+} /* dns_rr_exists() */
+
+
+static unsigned short dns_rr_offset(struct dns_rr *rr) {
+ return rr->dn.p;
+} /* dns_rr_offset() */
+
+
+static _Bool dns_rr_i_match(struct dns_rr *rr, struct dns_rr_i *i, struct dns_packet *P) {
+ if (i->section && !(rr->section & i->section))
+ return 0;
+
+ if (i->type && rr->type != i->type && i->type != DNS_T_ALL)
+ return 0;
+
+ if (i->class && rr->class != i->class && i->class != DNS_C_ANY)
+ return 0;
+
+ if (i->name) {
+ char dn[DNS_D_MAXNAME + 1];
+ size_t len;
+ int error;
+
+ if (!(len = dns_d_expand(dn, sizeof dn, rr->dn.p, P, &error))
+ || len >= sizeof dn)
+ return 0;
+
+ if (0 != strcasecmp(dn, i->name))
+ return 0;
+ }
+
+ if (i->data && i->type && rr->section > DNS_S_QD) {
+ union dns_any rd;
+ int error;
+
+ if ((error = dns_any_parse(&rd, rr, P)))
+ return 0;
+
+ if (0 != dns_any_cmp(&rd, rr->type, i->data, i->type))
+ return 0;
+ }
+
+ return 1;
+} /* dns_rr_i_match() */
+
+
+static unsigned short dns_rr_i_start(struct dns_rr_i *i, struct dns_packet *P) {
+ unsigned short rp;
+ struct dns_rr r0, rr;
+ int error;
+
+ if ((i->section & DNS_S_QD) && P->memo.qd.base)
+ rp = P->memo.qd.base;
+ else if ((i->section & DNS_S_AN) && P->memo.an.base)
+ rp = P->memo.an.base;
+ else if ((i->section & DNS_S_NS) && P->memo.ns.base)
+ rp = P->memo.ns.base;
+ else if ((i->section & DNS_S_AR) && P->memo.ar.base)
+ rp = P->memo.ar.base;
+ else
+ rp = 12;
+
+ for (; rp < P->end; rp = dns_rr_skip(rp, P)) {
+ if ((error = dns_rr_parse(&rr, rp, P)))
+ continue;
+
+ rr.section = dns_rr_section(rp, P);
+
+ if (!dns_rr_i_match(&rr, i, P))
+ continue;
+
+ r0 = rr;
+
+ goto lower;
+ }
+
+ return P->end;
+lower:
+ if (i->sort == &dns_rr_i_packet)
+ return dns_rr_offset(&r0);
+
+ while ((rp = dns_rr_skip(rp, P)) < P->end) {
+ if ((error = dns_rr_parse(&rr, rp, P)))
+ continue;
+
+ rr.section = dns_rr_section(rp, P);
+
+ if (!dns_rr_i_match(&rr, i, P))
+ continue;
+
+ if (i->sort(&rr, &r0, i, P) < 0)
+ r0 = rr;
+ }
+
+ return dns_rr_offset(&r0);
+} /* dns_rr_i_start() */
+
+
+static unsigned short dns_rr_i_skip(unsigned short rp, struct dns_rr_i *i, struct dns_packet *P) {
+ struct dns_rr r0, r1, rr;
+ int error;
+
+ if ((error = dns_rr_parse(&r0, rp, P)))
+ return P->end;
+
+ r0.section = dns_rr_section(rp, P);
+
+ rp = (i->sort == &dns_rr_i_packet)? dns_rr_skip(rp, P) : 12;
+
+ for (; rp < P->end; rp = dns_rr_skip(rp, P)) {
+ if ((error = dns_rr_parse(&rr, rp, P)))
+ continue;
+
+ rr.section = dns_rr_section(rp, P);
+
+ if (!dns_rr_i_match(&rr, i, P))
+ continue;
+
+ if (i->sort(&rr, &r0, i, P) <= 0)
+ continue;
+
+ r1 = rr;
+
+ goto lower;
+ }
+
+ return P->end;
+lower:
+ if (i->sort == &dns_rr_i_packet)
+ return dns_rr_offset(&r1);
+
+ while ((rp = dns_rr_skip(rp, P)) < P->end) {
+ if ((error = dns_rr_parse(&rr, rp, P)))
+ continue;
+
+ rr.section = dns_rr_section(rp, P);
+
+ if (!dns_rr_i_match(&rr, i, P))
+ continue;
+
+ if (i->sort(&rr, &r0, i, P) <= 0)
+ continue;
+
+ if (i->sort(&rr, &r1, i, P) >= 0)
+ continue;
+
+ r1 = rr;
+ }
+
+ return dns_rr_offset(&r1);
+} /* dns_rr_i_skip() */
+
+
+int dns_rr_i_packet(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) {
+ (void)i;
+ (void)P;
+
+ return (int)a->dn.p - (int)b->dn.p;
+} /* dns_rr_i_packet() */
+
+
+int dns_rr_i_order(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) {
+ int cmp;
+
+ (void)i;
+
+ if ((cmp = a->section - b->section))
+ return cmp;
+
+ if (a->type != b->type)
+ return (int)a->dn.p - (int)b->dn.p;
+
+ return dns_rr_cmp(a, P, b, P);
+} /* dns_rr_i_order() */
+
+
+int dns_rr_i_shuffle(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) {
+ int cmp;
+
+ (void)i;
+ (void)P;
+
+ while (!i->state.regs[0])
+ i->state.regs[0] = dns_random();
+
+ if ((cmp = a->section - b->section))
+ return cmp;
+
+ return dns_k_shuffle16(a->dn.p, i->state.regs[0]) - dns_k_shuffle16(b->dn.p, i->state.regs[0]);
+} /* dns_rr_i_shuffle() */
+
+
+struct dns_rr_i *dns_rr_i_init(struct dns_rr_i *i, struct dns_packet *P) {
+ static const struct dns_rr_i i_initializer;
+
+ (void)P;
+
+ i->state = i_initializer.state;
+ i->saved = i->state;
+
+ return i;
+} /* dns_rr_i_init() */
+
+
+unsigned dns_rr_grep(struct dns_rr *rr, unsigned lim, struct dns_rr_i *i, struct dns_packet *P, int *error_) {
+ unsigned count = 0;
+ int error;
+
+ switch (i->state.exec) {
+ case 0:
+ if (!i->sort)
+ i->sort = &dns_rr_i_packet;
+
+ i->state.next = dns_rr_i_start(i, P);
+ i->state.exec++;
+
+ /* FALL THROUGH */
+ case 1:
+ while (count < lim && i->state.next < P->end) {
+ if ((error = dns_rr_parse(rr, i->state.next, P)))
+ goto error;
+
+ rr->section = dns_rr_section(i->state.next, P);
+
+ rr++;
+ count++;
+ i->state.count++;
+
+ i->state.next = dns_rr_i_skip(i->state.next, i, P);
+ } /* while() */
+
+ break;
+ } /* switch() */
+
+ return count;
+error:
+ *error_ = error;
+
+ return count;
+} /* dns_rr_grep() */
+
+
+size_t dns_rr_print(void *_dst, size_t lim, struct dns_rr *rr, struct dns_packet *P, int *_error) {
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+ union dns_any any;
+ size_t n;
+ int error;
+
+ if (rr->section == DNS_S_QD)
+ dns_b_putc(&dst, ';');
+
+ if (!(n = dns_d_expand(any.ns.host, sizeof any.ns.host, rr->dn.p, P, &error)))
+ goto error;
+ dns_b_put(&dst, any.ns.host, DNS_PP_MIN(n, sizeof any.ns.host - 1));
+
+ if (rr->section != DNS_S_QD) {
+ dns_b_putc(&dst, ' ');
+ dns_b_fmtju(&dst, rr->ttl, 0);
+ }
+
+ dns_b_putc(&dst, ' ');
+ dns_b_puts(&dst, dns_strclass(rr->class));
+ dns_b_putc(&dst, ' ');
+ dns_b_puts(&dst, dns_strtype(rr->type));
+
+ if (rr->section == DNS_S_QD)
+ goto epilog;
+
+ dns_b_putc(&dst, ' ');
+
+ if ((error = dns_any_parse(dns_any_init(&any, sizeof any), rr, P)))
+ goto error;
+
+ n = dns_any_print(dst.p, dst.pe - dst.p, &any, rr->type);
+ dst.p += DNS_PP_MIN(n, (size_t)(dst.pe - dst.p));
+epilog:
+ return dns_b_strllen(&dst);
+error:
+ *_error = error;
+
+ return 0;
+} /* dns_rr_print() */
+
+
+int dns_a_parse(struct dns_a *a, struct dns_rr *rr, struct dns_packet *P) {
+ unsigned long addr;
+
+ if (rr->rd.len != 4)
+ return DNS_EILLEGAL;
+
+ addr = ((0xffU & P->data[rr->rd.p + 0]) << 24)
+ | ((0xffU & P->data[rr->rd.p + 1]) << 16)
+ | ((0xffU & P->data[rr->rd.p + 2]) << 8)
+ | ((0xffU & P->data[rr->rd.p + 3]) << 0);
+
+ a->addr.s_addr = htonl(addr);
+
+ return 0;
+} /* dns_a_parse() */
+
+
+int dns_a_push(struct dns_packet *P, struct dns_a *a) {
+ unsigned long addr;
+
+ if (P->size - P->end < 6)
+ return DNS_ENOBUFS;
+
+ P->data[P->end++] = 0x00;
+ P->data[P->end++] = 0x04;
+
+ addr = ntohl(a->addr.s_addr);
+
+ P->data[P->end++] = 0xffU & (addr >> 24);
+ P->data[P->end++] = 0xffU & (addr >> 16);
+ P->data[P->end++] = 0xffU & (addr >> 8);
+ P->data[P->end++] = 0xffU & (addr >> 0);
+
+ return 0;
+} /* dns_a_push() */
+
+
+size_t dns_a_arpa(void *_dst, size_t lim, const struct dns_a *a) {
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+ unsigned long octets = ntohl(a->addr.s_addr);
+ unsigned i;
+
+ for (i = 0; i < 4; i++) {
+ dns_b_fmtju(&dst, 0xff & octets, 0);
+ dns_b_putc(&dst, '.');
+ octets >>= 8;
+ }
+
+ dns_b_puts(&dst, "in-addr.arpa.");
+
+ return dns_b_strllen(&dst);
+} /* dns_a_arpa() */
+
+
+int dns_a_cmp(const struct dns_a *a, const struct dns_a *b) {
+ if (ntohl(a->addr.s_addr) < ntohl(b->addr.s_addr))
+ return -1;
+ if (ntohl(a->addr.s_addr) > ntohl(b->addr.s_addr))
+ return 1;
+
+ return 0;
+} /* dns_a_cmp() */
+
+
+size_t dns_a_print(void *dst, size_t lim, struct dns_a *a) {
+ char addr[INET_ADDRSTRLEN + 1] = "0.0.0.0";
+
+ dns_inet_ntop(AF_INET, &a->addr, addr, sizeof addr);
+
+ return dns_strlcpy(dst, addr, lim);
+} /* dns_a_print() */
+
+
+int dns_aaaa_parse(struct dns_aaaa *aaaa, struct dns_rr *rr, struct dns_packet *P) {
+ if (rr->rd.len != sizeof aaaa->addr.s6_addr)
+ return DNS_EILLEGAL;
+
+ memcpy(aaaa->addr.s6_addr, &P->data[rr->rd.p], sizeof aaaa->addr.s6_addr);
+
+ return 0;
+} /* dns_aaaa_parse() */
+
+
+int dns_aaaa_push(struct dns_packet *P, struct dns_aaaa *aaaa) {
+ if (P->size - P->end < 2 + sizeof aaaa->addr.s6_addr)
+ return DNS_ENOBUFS;
+
+ P->data[P->end++] = 0x00;
+ P->data[P->end++] = 0x10;
+
+ memcpy(&P->data[P->end], aaaa->addr.s6_addr, sizeof aaaa->addr.s6_addr);
+
+ P->end += sizeof aaaa->addr.s6_addr;
+
+ return 0;
+} /* dns_aaaa_push() */
+
+
+int dns_aaaa_cmp(const struct dns_aaaa *a, const struct dns_aaaa *b) {
+ unsigned i;
+ int cmp;
+
+ for (i = 0; i < lengthof(a->addr.s6_addr); i++) {
+ if ((cmp = (a->addr.s6_addr[i] - b->addr.s6_addr[i])))
+ return cmp;
+ }
+
+ return 0;
+} /* dns_aaaa_cmp() */
+
+
+size_t dns_aaaa_arpa(void *_dst, size_t lim, const struct dns_aaaa *aaaa) {
+ static const unsigned char hex[16] = "0123456789abcdef";
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+ unsigned nyble;
+ int i, j;
+
+ for (i = sizeof aaaa->addr.s6_addr - 1; i >= 0; i--) {
+ nyble = aaaa->addr.s6_addr[i];
+
+ for (j = 0; j < 2; j++) {
+ dns_b_putc(&dst, hex[0x0f & nyble]);
+ dns_b_putc(&dst, '.');
+ nyble >>= 4;
+ }
+ }
+
+ dns_b_puts(&dst, "ip6.arpa.");
+
+ return dns_b_strllen(&dst);
+} /* dns_aaaa_arpa() */
+
+
+size_t dns_aaaa_print(void *dst, size_t lim, struct dns_aaaa *aaaa) {
+ char addr[INET6_ADDRSTRLEN + 1] = "::";
+
+ dns_inet_ntop(AF_INET6, &aaaa->addr, addr, sizeof addr);
+
+ return dns_strlcpy(dst, addr, lim);
+} /* dns_aaaa_print() */
+
+
+int dns_mx_parse(struct dns_mx *mx, struct dns_rr *rr, struct dns_packet *P) {
+ size_t len;
+ int error;
+
+ if (rr->rd.len < 3)
+ return DNS_EILLEGAL;
+
+ mx->preference = (0xff00 & (P->data[rr->rd.p + 0] << 8))
+ | (0x00ff & (P->data[rr->rd.p + 1] << 0));
+
+ if (!(len = dns_d_expand(mx->host, sizeof mx->host, rr->rd.p + 2, P, &error)))
+ return error;
+ else if (len >= sizeof mx->host)
+ return DNS_EILLEGAL;
+
+ return 0;
+} /* dns_mx_parse() */
+
+
+int dns_mx_push(struct dns_packet *P, struct dns_mx *mx) {
+ size_t end, len;
+ int error;
+
+ if (P->size - P->end < 5)
+ return DNS_ENOBUFS;
+
+ end = P->end;
+ P->end += 2;
+
+ P->data[P->end++] = 0xff & (mx->preference >> 8);
+ P->data[P->end++] = 0xff & (mx->preference >> 0);
+
+ if ((error = dns_d_push(P, mx->host, strlen(mx->host))))
+ goto error;
+
+ len = P->end - end - 2;
+
+ P->data[end + 0] = 0xff & (len >> 8);
+ P->data[end + 1] = 0xff & (len >> 0);
+
+ return 0;
+error:
+ P->end = end;
+
+ return error;
+} /* dns_mx_push() */
+
+
+int dns_mx_cmp(const struct dns_mx *a, const struct dns_mx *b) {
+ int cmp;
+
+ if ((cmp = a->preference - b->preference))
+ return cmp;
+
+ return strcasecmp(a->host, b->host);
+} /* dns_mx_cmp() */
+
+
+size_t dns_mx_print(void *_dst, size_t lim, struct dns_mx *mx) {
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+
+ dns_b_fmtju(&dst, mx->preference, 0);
+ dns_b_putc(&dst, ' ');
+ dns_b_puts(&dst, mx->host);
+
+ return dns_b_strllen(&dst);
+} /* dns_mx_print() */
+
+
+size_t dns_mx_cname(void *dst, size_t lim, struct dns_mx *mx) {
+ return dns_strlcpy(dst, mx->host, lim);
+} /* dns_mx_cname() */
+
+
+int dns_ns_parse(struct dns_ns *ns, struct dns_rr *rr, struct dns_packet *P) {
+ size_t len;
+ int error;
+
+ if (!(len = dns_d_expand(ns->host, sizeof ns->host, rr->rd.p, P, &error)))
+ return error;
+ else if (len >= sizeof ns->host)
+ return DNS_EILLEGAL;
+
+ return 0;
+} /* dns_ns_parse() */
+
+
+int dns_ns_push(struct dns_packet *P, struct dns_ns *ns) {
+ size_t end, len;
+ int error;
+
+ if (P->size - P->end < 3)
+ return DNS_ENOBUFS;
+
+ end = P->end;
+ P->end += 2;
+
+ if ((error = dns_d_push(P, ns->host, strlen(ns->host))))
+ goto error;
+
+ len = P->end - end - 2;
+
+ P->data[end + 0] = 0xff & (len >> 8);
+ P->data[end + 1] = 0xff & (len >> 0);
+
+ return 0;
+error:
+ P->end = end;
+
+ return error;
+} /* dns_ns_push() */
+
+
+int dns_ns_cmp(const struct dns_ns *a, const struct dns_ns *b) {
+ return strcasecmp(a->host, b->host);
+} /* dns_ns_cmp() */
+
+
+size_t dns_ns_print(void *dst, size_t lim, struct dns_ns *ns) {
+ return dns_strlcpy(dst, ns->host, lim);
+} /* dns_ns_print() */
+
+
+size_t dns_ns_cname(void *dst, size_t lim, struct dns_ns *ns) {
+ return dns_strlcpy(dst, ns->host, lim);
+} /* dns_ns_cname() */
+
+
+int dns_cname_parse(struct dns_cname *cname, struct dns_rr *rr, struct dns_packet *P) {
+ return dns_ns_parse((struct dns_ns *)cname, rr, P);
+} /* dns_cname_parse() */
+
+
+int dns_cname_push(struct dns_packet *P, struct dns_cname *cname) {
+ return dns_ns_push(P, (struct dns_ns *)cname);
+} /* dns_cname_push() */
+
+
+int dns_cname_cmp(const struct dns_cname *a, const struct dns_cname *b) {
+ return strcasecmp(a->host, b->host);
+} /* dns_cname_cmp() */
+
+
+size_t dns_cname_print(void *dst, size_t lim, struct dns_cname *cname) {
+ return dns_ns_print(dst, lim, (struct dns_ns *)cname);
+} /* dns_cname_print() */
+
+
+size_t dns_cname_cname(void *dst, size_t lim, struct dns_cname *cname) {
+ return dns_strlcpy(dst, cname->host, lim);
+} /* dns_cname_cname() */
+
+
+int dns_soa_parse(struct dns_soa *soa, struct dns_rr *rr, struct dns_packet *P) {
+ struct { void *dst; size_t lim; } dn[] =
+ { { soa->mname, sizeof soa->mname },
+ { soa->rname, sizeof soa->rname } };
+ unsigned *ts[] =
+ { &soa->serial, &soa->refresh, &soa->retry, &soa->expire, &soa->minimum };
+ unsigned short rp;
+ unsigned i, j, n;
+ int error;
+
+ /* MNAME / RNAME */
+ if ((rp = rr->rd.p) >= P->end)
+ return DNS_EILLEGAL;
+
+ for (i = 0; i < lengthof(dn); i++) {
+ if (!(n = dns_d_expand(dn[i].dst, dn[i].lim, rp, P, &error)))
+ return error;
+ else if (n >= dn[i].lim)
+ return DNS_EILLEGAL;
+
+ if ((rp = dns_d_skip(rp, P)) >= P->end)
+ return DNS_EILLEGAL;
+ }
+
+ /* SERIAL / REFRESH / RETRY / EXPIRE / MINIMUM */
+ for (i = 0; i < lengthof(ts); i++) {
+ for (j = 0; j < 4; j++, rp++) {
+ if (rp >= P->end)
+ return DNS_EILLEGAL;
+
+ *ts[i] <<= 8;
+ *ts[i] |= (0xff & P->data[rp]);
+ }
+ }
+
+ return 0;
+} /* dns_soa_parse() */
+
+
+int dns_soa_push(struct dns_packet *P, struct dns_soa *soa) {
+ void *dn[] = { soa->mname, soa->rname };
+ unsigned ts[] = { (0xffffffff & soa->serial),
+ (0x7fffffff & soa->refresh),
+ (0x7fffffff & soa->retry),
+ (0x7fffffff & soa->expire),
+ (0xffffffff & soa->minimum) };
+ unsigned i, j;
+ size_t end, len;
+ int error;
+
+ end = P->end;
+
+ if ((P->end += 2) >= P->size)
+ goto toolong;
+
+ /* MNAME / RNAME */
+ for (i = 0; i < lengthof(dn); i++) {
+ if ((error = dns_d_push(P, dn[i], strlen(dn[i]))))
+ goto error;
+ }
+
+ /* SERIAL / REFRESH / RETRY / EXPIRE / MINIMUM */
+ for (i = 0; i < lengthof(ts); i++) {
+ if ((P->end += 4) >= P->size)
+ goto toolong;
+
+ for (j = 1; j <= 4; j++) {
+ P->data[P->end - j] = (0xff & ts[i]);
+ ts[i] >>= 8;
+ }
+ }
+
+ len = P->end - end - 2;
+ P->data[end + 0] = (0xff & (len >> 8));
+ P->data[end + 1] = (0xff & (len >> 0));
+
+ return 0;
+toolong:
+ error = DNS_ENOBUFS;
+
+ /* FALL THROUGH */
+error:
+ P->end = end;
+
+ return error;
+} /* dns_soa_push() */
+
+
+int dns_soa_cmp(const struct dns_soa *a, const struct dns_soa *b) {
+ int cmp;
+
+ if ((cmp = strcasecmp(a->mname, b->mname)))
+ return cmp;
+
+ if ((cmp = strcasecmp(a->rname, b->rname)))
+ return cmp;
+
+ if (a->serial > b->serial)
+ return -1;
+ else if (a->serial < b->serial)
+ return 1;
+
+ if (a->refresh > b->refresh)
+ return -1;
+ else if (a->refresh < b->refresh)
+ return 1;
+
+ if (a->retry > b->retry)
+ return -1;
+ else if (a->retry < b->retry)
+ return 1;
+
+ if (a->expire > b->expire)
+ return -1;
+ else if (a->expire < b->expire)
+ return 1;
+
+ if (a->minimum > b->minimum)
+ return -1;
+ else if (a->minimum < b->minimum)
+ return 1;
+
+ return 0;
+} /* dns_soa_cmp() */
+
+
+size_t dns_soa_print(void *_dst, size_t lim, struct dns_soa *soa) {
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+
+ dns_b_puts(&dst, soa->mname);
+ dns_b_putc(&dst, ' ');
+ dns_b_puts(&dst, soa->rname);
+ dns_b_putc(&dst, ' ');
+ dns_b_fmtju(&dst, soa->serial, 0);
+ dns_b_putc(&dst, ' ');
+ dns_b_fmtju(&dst, soa->refresh, 0);
+ dns_b_putc(&dst, ' ');
+ dns_b_fmtju(&dst, soa->retry, 0);
+ dns_b_putc(&dst, ' ');
+ dns_b_fmtju(&dst, soa->expire, 0);
+ dns_b_putc(&dst, ' ');
+ dns_b_fmtju(&dst, soa->minimum, 0);
+
+ return dns_b_strllen(&dst);
+} /* dns_soa_print() */
+
+
+int dns_srv_parse(struct dns_srv *srv, struct dns_rr *rr, struct dns_packet *P) {
+ unsigned short rp;
+ unsigned i;
+ size_t n;
+ int error;
+
+ memset(srv, '\0', sizeof *srv);
+
+ rp = rr->rd.p;
+
+ if (rr->rd.len < 7)
+ return DNS_EILLEGAL;
+
+ for (i = 0; i < 2; i++, rp++) {
+ srv->priority <<= 8;
+ srv->priority |= (0xff & P->data[rp]);
+ }
+
+ for (i = 0; i < 2; i++, rp++) {
+ srv->weight <<= 8;
+ srv->weight |= (0xff & P->data[rp]);
+ }
+
+ for (i = 0; i < 2; i++, rp++) {
+ srv->port <<= 8;
+ srv->port |= (0xff & P->data[rp]);
+ }
+
+ if (!(n = dns_d_expand(srv->target, sizeof srv->target, rp, P, &error)))
+ return error;
+ else if (n >= sizeof srv->target)
+ return DNS_EILLEGAL;
+
+ return 0;
+} /* dns_srv_parse() */
+
+
+int dns_srv_push(struct dns_packet *P, struct dns_srv *srv) {
+ size_t end, len;
+ int error;
+
+ end = P->end;
+
+ if (P->size - P->end < 2)
+ goto toolong;
+
+ P->end += 2;
+
+ if (P->size - P->end < 6)
+ goto toolong;
+
+ P->data[P->end++] = 0xff & (srv->priority >> 8);
+ P->data[P->end++] = 0xff & (srv->priority >> 0);
+
+ P->data[P->end++] = 0xff & (srv->weight >> 8);
+ P->data[P->end++] = 0xff & (srv->weight >> 0);
+
+ P->data[P->end++] = 0xff & (srv->port >> 8);
+ P->data[P->end++] = 0xff & (srv->port >> 0);
+
+ if (0 == (len = dns_d_comp(&P->data[P->end], P->size - P->end, srv->target, strlen(srv->target), P, &error)))
+ goto error;
+ else if (P->size - P->end < len)
+ goto toolong;
+
+ P->end += len;
+
+ if (P->end > 65535)
+ goto toolong;
+
+ len = P->end - end - 2;
+
+ P->data[end + 0] = 0xff & (len >> 8);
+ P->data[end + 1] = 0xff & (len >> 0);
+
+ return 0;
+toolong:
+ error = DNS_ENOBUFS;
+
+ /* FALL THROUGH */
+error:
+ P->end = end;
+
+ return error;
+} /* dns_srv_push() */
+
+
+int dns_srv_cmp(const struct dns_srv *a, const struct dns_srv *b) {
+ int cmp;
+
+ if ((cmp = a->priority - b->priority))
+ return cmp;
+
+ /*
+ * FIXME: We need some sort of random seed to implement the dynamic
+ * weighting required by RFC 2782.
+ */
+ if ((cmp = a->weight - b->weight))
+ return cmp;
+
+ if ((cmp = a->port - b->port))
+ return cmp;
+
+ return strcasecmp(a->target, b->target);
+} /* dns_srv_cmp() */
+
+
+size_t dns_srv_print(void *_dst, size_t lim, struct dns_srv *srv) {
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+
+ dns_b_fmtju(&dst, srv->priority, 0);
+ dns_b_putc(&dst, ' ');
+ dns_b_fmtju(&dst, srv->weight, 0);
+ dns_b_putc(&dst, ' ');
+ dns_b_fmtju(&dst, srv->port, 0);
+ dns_b_putc(&dst, ' ');
+ dns_b_puts(&dst, srv->target);
+
+ return dns_b_strllen(&dst);
+} /* dns_srv_print() */
+
+
+size_t dns_srv_cname(void *dst, size_t lim, struct dns_srv *srv) {
+ return dns_strlcpy(dst, srv->target, lim);
+} /* dns_srv_cname() */
+
+
+unsigned int dns_opt_ttl(const struct dns_opt *opt) {
+ unsigned int ttl = 0;
+
+ ttl |= (0xffU & opt->rcode) << 24;
+ ttl |= (0xffU & opt->version) << 16;
+ ttl |= (0xffffU & opt->flags) << 0;
+
+ return ttl;
+} /* dns_opt_ttl() */
+
+
+unsigned short dns_opt_class(const struct dns_opt *opt) {
+ return opt->maxudp;
+} /* dns_opt_class() */
+
+
+struct dns_opt *dns_opt_init(struct dns_opt *opt, size_t size) {
+ assert(size >= offsetof(struct dns_opt, data));
+
+ opt->size = size - offsetof(struct dns_opt, data);
+ opt->len = 0;
+
+ opt->rcode = 0;
+ opt->version = 0;
+ opt->maxudp = 0;
+
+ return opt;
+} /* dns_opt_init() */
+
+
+static union dns_any *dns_opt_initany(union dns_any *any, size_t size) {
+ return dns_opt_init(&any->opt, size), any;
+} /* dns_opt_initany() */
+
+
+int dns_opt_parse(struct dns_opt *opt, struct dns_rr *rr, struct dns_packet *P) {
+ const struct dns_buf src = DNS_B_FROM(&P->data[rr->rd.p], rr->rd.len);
+ struct dns_buf dst = DNS_B_INTO(opt->data, opt->size);
+ int error;
+
+ opt->rcode = 0xfff & ((rr->ttl >> 20) | dns_header(P)->rcode);
+ opt->version = 0xff & (rr->ttl >> 16);
+ opt->flags = 0xffff & rr->ttl;
+ opt->maxudp = 0xffff & rr->class;
+
+ while (src.p < src.pe) {
+ int code, len;
+
+ if (-1 == (code = dns_b_get16(&src, -1)))
+ return src.error;
+ if (-1 == (len = dns_b_get16(&src, -1)))
+ return src.error;
+
+ switch (code) {
+ default:
+ dns_b_put16(&dst, code);
+ dns_b_put16(&dst, len);
+ if ((error = dns_b_move(&dst, &src, len)))
+ return error;
+ break;
+ }
+ }
+
+ return 0;
+} /* dns_opt_parse() */
+
+
+int dns_opt_push(struct dns_packet *P, struct dns_opt *opt) {
+ const struct dns_buf src = DNS_B_FROM(opt->data, opt->len);
+ struct dns_buf dst = DNS_B_INTO(&P->data[P->end], (P->size - P->end));
+ int error;
+
+ /* rdata length (see below) */
+ if ((error = dns_b_put16(&dst, 0)))
+ goto error;
+
+ /* ... push known options here */
+
+ /* push opaque option data */
+ if ((error = dns_b_move(&dst, &src, (size_t)(src.pe - src.p))))
+ goto error;
+
+ /* rdata length */
+ if ((error = dns_b_pput16(&dst, dns_b_tell(&dst) - 2, 0)))
+ goto error;
+
+#if !DNS_DEBUG_OPT_FORMERR
+ P->end += dns_b_tell(&dst);
+#endif
+
+ return 0;
+error:
+ return error;
+} /* dns_opt_push() */
+
+
+int dns_opt_cmp(const struct dns_opt *a, const struct dns_opt *b) {
+ (void)a;
+ (void)b;
+
+ return -1;
+} /* dns_opt_cmp() */
+
+
+size_t dns_opt_print(void *_dst, size_t lim, struct dns_opt *opt) {
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+ size_t p;
+
+ dns_b_putc(&dst, '"');
+
+ for (p = 0; p < opt->len; p++) {
+ dns_b_putc(&dst, '\\');
+ dns_b_fmtju(&dst, opt->data[p], 3);
+ }
+
+ dns_b_putc(&dst, '"');
+
+ return dns_b_strllen(&dst);
+} /* dns_opt_print() */
+
+
+int dns_ptr_parse(struct dns_ptr *ptr, struct dns_rr *rr, struct dns_packet *P) {
+ return dns_ns_parse((struct dns_ns *)ptr, rr, P);
+} /* dns_ptr_parse() */
+
+
+int dns_ptr_push(struct dns_packet *P, struct dns_ptr *ptr) {
+ return dns_ns_push(P, (struct dns_ns *)ptr);
+} /* dns_ptr_push() */
+
+
+size_t dns_ptr_qname(void *dst, size_t lim, int af, void *addr) {
+ switch (af) {
+ case AF_INET6:
+ return dns_aaaa_arpa(dst, lim, addr);
+ case AF_INET:
+ return dns_a_arpa(dst, lim, addr);
+ default: {
+ struct dns_a a;
+ a.addr.s_addr = INADDR_NONE;
+ return dns_a_arpa(dst, lim, &a);
+ }
+ }
+} /* dns_ptr_qname() */
+
+
+int dns_ptr_cmp(const struct dns_ptr *a, const struct dns_ptr *b) {
+ return strcasecmp(a->host, b->host);
+} /* dns_ptr_cmp() */
+
+
+size_t dns_ptr_print(void *dst, size_t lim, struct dns_ptr *ptr) {
+ return dns_ns_print(dst, lim, (struct dns_ns *)ptr);
+} /* dns_ptr_print() */
+
+
+size_t dns_ptr_cname(void *dst, size_t lim, struct dns_ptr *ptr) {
+ return dns_strlcpy(dst, ptr->host, lim);
+} /* dns_ptr_cname() */
+
+
+int dns_sshfp_parse(struct dns_sshfp *fp, struct dns_rr *rr, struct dns_packet *P) {
+ unsigned p = rr->rd.p, pe = rr->rd.p + rr->rd.len;
+
+ if (pe - p < 2)
+ return DNS_EILLEGAL;
+
+ fp->algo = P->data[p++];
+ fp->type = P->data[p++];
+
+ switch (fp->type) {
+ case DNS_SSHFP_SHA1:
+ if (pe - p < sizeof fp->digest.sha1)
+ return DNS_EILLEGAL;
+
+ memcpy(fp->digest.sha1, &P->data[p], sizeof fp->digest.sha1);
+
+ break;
+ default:
+ break;
+ } /* switch() */
+
+ return 0;
+} /* dns_sshfp_parse() */
+
+
+int dns_sshfp_push(struct dns_packet *P, struct dns_sshfp *fp) {
+ unsigned p = P->end, pe = P->size, n;
+
+ if (pe - p < 4)
+ return DNS_ENOBUFS;
+
+ p += 2;
+ P->data[p++] = 0xff & fp->algo;
+ P->data[p++] = 0xff & fp->type;
+
+ switch (fp->type) {
+ case DNS_SSHFP_SHA1:
+ if (pe - p < sizeof fp->digest.sha1)
+ return DNS_ENOBUFS;
+
+ memcpy(&P->data[p], fp->digest.sha1, sizeof fp->digest.sha1);
+ p += sizeof fp->digest.sha1;
+
+ break;
+ default:
+ return DNS_EILLEGAL;
+ } /* switch() */
+
+ n = p - P->end - 2;
+ P->data[P->end++] = 0xff & (n >> 8);
+ P->data[P->end++] = 0xff & (n >> 0);
+ P->end = p;
+
+ return 0;
+} /* dns_sshfp_push() */
+
+
+int dns_sshfp_cmp(const struct dns_sshfp *a, const struct dns_sshfp *b) {
+ int cmp;
+
+ if ((cmp = a->algo - b->algo) || (cmp = a->type - b->type))
+ return cmp;
+
+ switch (a->type) {
+ case DNS_SSHFP_SHA1:
+ return memcmp(a->digest.sha1, b->digest.sha1, sizeof a->digest.sha1);
+ default:
+ return 0;
+ } /* switch() */
+
+ /* NOT REACHED */
+} /* dns_sshfp_cmp() */
+
+
+size_t dns_sshfp_print(void *_dst, size_t lim, struct dns_sshfp *fp) {
+ static const unsigned char hex[16] = "0123456789abcdef";
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+ size_t i;
+
+ dns_b_fmtju(&dst, fp->algo, 0);
+ dns_b_putc(&dst, ' ');
+ dns_b_fmtju(&dst, fp->type, 0);
+ dns_b_putc(&dst, ' ');
+
+ switch (fp->type) {
+ case DNS_SSHFP_SHA1:
+ for (i = 0; i < sizeof fp->digest.sha1; i++) {
+ dns_b_putc(&dst, hex[0x0f & (fp->digest.sha1[i] >> 4)]);
+ dns_b_putc(&dst, hex[0x0f & (fp->digest.sha1[i] >> 0)]);
+ }
+
+ break;
+ default:
+ dns_b_putc(&dst, '0');
+
+ break;
+ } /* switch() */
+
+ return dns_b_strllen(&dst);
+} /* dns_sshfp_print() */
+
+
+struct dns_txt *dns_txt_init(struct dns_txt *txt, size_t size) {
+ assert(size > offsetof(struct dns_txt, data));
+
+ txt->size = size - offsetof(struct dns_txt, data);
+ txt->len = 0;
+
+ return txt;
+} /* dns_txt_init() */
+
+
+static union dns_any *dns_txt_initany(union dns_any *any, size_t size) {
+ /* NB: union dns_any is already initialized as struct dns_txt */
+ (void)size;
+ return any;
+} /* dns_txt_initany() */
+
+
+int dns_txt_parse(struct dns_txt *txt, struct dns_rr *rr, struct dns_packet *P) {
+ struct { unsigned char *b; size_t p, end; } dst, src;
+ unsigned n;
+
+ dst.b = txt->data;
+ dst.p = 0;
+ dst.end = txt->size;
+
+ src.b = P->data;
+ src.p = rr->rd.p;
+ src.end = src.p + rr->rd.len;
+
+ while (src.p < src.end) {
+ n = 0xff & P->data[src.p++];
+
+ if (src.end - src.p < n || dst.end - dst.p < n)
+ return DNS_EILLEGAL;
+
+ memcpy(&dst.b[dst.p], &src.b[src.p], n);
+
+ dst.p += n;
+ src.p += n;
+ }
+
+ txt->len = dst.p;
+
+ return 0;
+} /* dns_txt_parse() */
+
+
+int dns_txt_push(struct dns_packet *P, struct dns_txt *txt) {
+ struct { unsigned char *b; size_t p, end; } dst, src;
+ unsigned n;
+
+ dst.b = P->data;
+ dst.p = P->end;
+ dst.end = P->size;
+
+ src.b = txt->data;
+ src.p = 0;
+ src.end = txt->len;
+
+ if (dst.end - dst.p < 2)
+ return DNS_ENOBUFS;
+
+ n = txt->len + ((txt->len + 254) / 255);
+
+ dst.b[dst.p++] = 0xff & (n >> 8);
+ dst.b[dst.p++] = 0xff & (n >> 0);
+
+ while (src.p < src.end) {
+ n = DNS_PP_MIN(255, src.end - src.p);
+
+ if (dst.p >= dst.end)
+ return DNS_ENOBUFS;
+
+ dst.b[dst.p++] = n;
+
+ if (dst.end - dst.p < n)
+ return DNS_ENOBUFS;
+
+ memcpy(&dst.b[dst.p], &src.b[src.p], n);
+
+ dst.p += n;
+ src.p += n;
+ }
+
+ P->end = dst.p;
+
+ return 0;
+} /* dns_txt_push() */
+
+
+int dns_txt_cmp(const struct dns_txt *a, const struct dns_txt *b) {
+ (void)a;
+ (void)b;
+
+ return -1;
+} /* dns_txt_cmp() */
+
+
+size_t dns_txt_print(void *_dst, size_t lim, struct dns_txt *txt) {
+ struct dns_buf src = DNS_B_FROM(txt->data, txt->len);
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+ unsigned i;
+
+ if (src.p < src.pe) {
+ do {
+ dns_b_putc(&dst, '"');
+
+ for (i = 0; i < 256 && src.p < src.pe; i++, src.p++) {
+ if (*src.p < 32 || *src.p > 126 || *src.p == '"' || *src.p == '\\') {
+ dns_b_putc(&dst, '\\');
+ dns_b_fmtju(&dst, *src.p, 3);
+ } else {
+ dns_b_putc(&dst, *src.p);
+ }
+ }
+
+ dns_b_putc(&dst, '"');
+ dns_b_putc(&dst, ' ');
+ } while (src.p < src.pe);
+
+ dns_b_popc(&dst);
+ } else {
+ dns_b_putc(&dst, '"');
+ dns_b_putc(&dst, '"');
+ }
+
+ return dns_b_strllen(&dst);
+} /* dns_txt_print() */
+
+
+static const struct dns_rrtype {
+ enum dns_type type;
+ const char *name;
+ union dns_any *(*init)(union dns_any *, size_t);
+ int (*parse)();
+ int (*push)();
+ int (*cmp)();
+ size_t (*print)();
+ size_t (*cname)();
+} dns_rrtypes[] = {
+ { DNS_T_A, "A", 0, &dns_a_parse, &dns_a_push, &dns_a_cmp, &dns_a_print, 0, },
+ { DNS_T_AAAA, "AAAA", 0, &dns_aaaa_parse, &dns_aaaa_push, &dns_aaaa_cmp, &dns_aaaa_print, 0, },
+ { DNS_T_MX, "MX", 0, &dns_mx_parse, &dns_mx_push, &dns_mx_cmp, &dns_mx_print, &dns_mx_cname, },
+ { DNS_T_NS, "NS", 0, &dns_ns_parse, &dns_ns_push, &dns_ns_cmp, &dns_ns_print, &dns_ns_cname, },
+ { DNS_T_CNAME, "CNAME", 0, &dns_cname_parse, &dns_cname_push, &dns_cname_cmp, &dns_cname_print, &dns_cname_cname, },
+ { DNS_T_SOA, "SOA", 0, &dns_soa_parse, &dns_soa_push, &dns_soa_cmp, &dns_soa_print, 0, },
+ { DNS_T_SRV, "SRV", 0, &dns_srv_parse, &dns_srv_push, &dns_srv_cmp, &dns_srv_print, &dns_srv_cname, },
+ { DNS_T_OPT, "OPT", &dns_opt_initany, &dns_opt_parse, &dns_opt_push, &dns_opt_cmp, &dns_opt_print, 0, },
+ { DNS_T_PTR, "PTR", 0, &dns_ptr_parse, &dns_ptr_push, &dns_ptr_cmp, &dns_ptr_print, &dns_ptr_cname, },
+ { DNS_T_TXT, "TXT", &dns_txt_initany, &dns_txt_parse, &dns_txt_push, &dns_txt_cmp, &dns_txt_print, 0, },
+ { DNS_T_SPF, "SPF", &dns_txt_initany, &dns_txt_parse, &dns_txt_push, &dns_txt_cmp, &dns_txt_print, 0, },
+ { DNS_T_SSHFP, "SSHFP", 0, &dns_sshfp_parse, &dns_sshfp_push, &dns_sshfp_cmp, &dns_sshfp_print, 0, },
+ { DNS_T_AXFR, "AXFR", 0, 0, 0, 0, 0, 0, },
+}; /* dns_rrtypes[] */
+
+static const struct dns_rrtype *dns_rrtype(enum dns_type type) {
+ const struct dns_rrtype *t;
+
+ for (t = dns_rrtypes; t < endof(dns_rrtypes); t++) {
+ if (t->type == type && t->parse) {
+ return t;
+ }
+ }
+
+ return NULL;
+} /* dns_rrtype() */
+
+
+union dns_any *dns_any_init(union dns_any *any, size_t size) {
+ dns_static_assert(dns_same_type(any->txt, any->rdata, 1), "unexpected rdata type");
+ return (union dns_any *)dns_txt_init(&any->rdata, size);
+} /* dns_any_init() */
+
+
+static size_t dns_any_sizeof(union dns_any *any) {
+ dns_static_assert(dns_same_type(any->txt, any->rdata, 1), "unexpected rdata type");
+ return offsetof(struct dns_txt, data) + any->rdata.size;
+} /* dns_any_sizeof() */
+
+static union dns_any *dns_any_reinit(union dns_any *any, const struct dns_rrtype *t) {
+ return (t->init)? t->init(any, dns_any_sizeof(any)) : any;
+} /* dns_any_reinit() */
+
+int dns_any_parse(union dns_any *any, struct dns_rr *rr, struct dns_packet *P) {
+ const struct dns_rrtype *t;
+
+ if ((t = dns_rrtype(rr->type)))
+ return t->parse(dns_any_reinit(any, t), rr, P);
+
+ if (rr->rd.len > any->rdata.size)
+ return DNS_EILLEGAL;
+
+ memcpy(any->rdata.data, &P->data[rr->rd.p], rr->rd.len);
+ any->rdata.len = rr->rd.len;
+
+ return 0;
+} /* dns_any_parse() */
+
+
+int dns_any_push(struct dns_packet *P, union dns_any *any, enum dns_type type) {
+ const struct dns_rrtype *t;
+
+ if ((t = dns_rrtype(type)))
+ return t->push(P, any);
+
+ if (P->size - P->end < any->rdata.len + 2)
+ return DNS_ENOBUFS;
+
+ P->data[P->end++] = 0xff & (any->rdata.len >> 8);
+ P->data[P->end++] = 0xff & (any->rdata.len >> 0);
+
+ memcpy(&P->data[P->end], any->rdata.data, any->rdata.len);
+ P->end += any->rdata.len;
+
+ return 0;
+} /* dns_any_push() */
+
+
+int dns_any_cmp(const union dns_any *a, enum dns_type x, const union dns_any *b, enum dns_type y) {
+ const struct dns_rrtype *t;
+ int cmp;
+
+ if ((cmp = x - y))
+ return cmp;
+
+ if ((t = dns_rrtype(x)))
+ return t->cmp(a, b);
+
+ return -1;
+} /* dns_any_cmp() */
+
+
+size_t dns_any_print(void *_dst, size_t lim, union dns_any *any, enum dns_type type) {
+ const struct dns_rrtype *t;
+ struct dns_buf src, dst;
+
+ if ((t = dns_rrtype(type)))
+ return t->print(_dst, lim, any);
+
+ dns_b_from(&src, any->rdata.data, any->rdata.len);
+ dns_b_into(&dst, _dst, lim);
+
+ dns_b_putc(&dst, '"');
+
+ while (src.p < src.pe) {
+ dns_b_putc(&dst, '\\');
+ dns_b_fmtju(&dst, *src.p++, 3);
+ }
+
+ dns_b_putc(&dst, '"');
+
+ return dns_b_strllen(&dst);
+} /* dns_any_print() */
+
+
+size_t dns_any_cname(void *dst, size_t lim, union dns_any *any, enum dns_type type) {
+ const struct dns_rrtype *t;
+
+ if ((t = dns_rrtype(type)) && t->cname)
+ return t->cname(dst, lim, any);
+
+ return 0;
+} /* dns_any_cname() */
+
+
+/*
+ * E V E N T T R A C I N G R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+#include <float.h> /* DBL_MANT_DIG */
+#include <inttypes.h> /* PRIu64 */
+
+/* for default trace ID generation try to fit in lua_Number, usually double */
+#define DNS_TRACE_ID_BITS DNS_PP_MIN(DBL_MANT_DIG, (sizeof (dns_trace_id_t) * CHAR_BIT)) /* assuming FLT_RADIX == 2 */
+#define DNS_TRACE_ID_MASK (((DNS_TRACE_ID_C(1) << (DNS_TRACE_ID_BITS - 1)) - 1) | (DNS_TRACE_ID_C(1) << (DNS_TRACE_ID_BITS - 1)))
+#define DNS_TRACE_ID_PRI PRIu64
+
+static inline dns_trace_id_t dns_trace_mkid(void) {
+ dns_trace_id_t id = 0;
+ unsigned r; /* return type of dns_random() */
+ const size_t id_bit = sizeof id * CHAR_BIT;
+ const size_t r_bit = sizeof r * CHAR_BIT;
+
+ for (size_t n = 0; n < id_bit; n += r_bit) {
+ r = dns_random();
+ id <<= r_bit;
+ id |= r;
+ }
+
+ return DNS_TRACE_ID_MASK & id;
+}
+
+struct dns_trace {
+ dns_atomic_t refcount;
+
+ FILE *fp;
+ dns_trace_id_t id;
+
+ struct {
+ struct dns_trace_cname {
+ char host[DNS_D_MAXNAME + 1];
+ struct sockaddr_storage addr;
+ } base[4];
+ size_t p;
+ } cnames;
+};
+
+static void dns_te_initname(struct sockaddr_storage *ss, int fd, int (*f)(int, struct sockaddr *, socklen_t *)) {
+ socklen_t n = sizeof *ss;
+
+ if (0 != f(fd, (struct sockaddr *)ss, &n))
+ goto unspec;
+
+ if (n > sizeof *ss)
+ goto unspec;
+
+ return;
+unspec:
+ memset(ss, '\0', sizeof *ss);
+ ss->ss_family = AF_UNSPEC;
+}
+
+static void dns_te_initnames(struct sockaddr_storage *local, struct sockaddr_storage *remote, int fd) {
+ dns_te_initname(local, fd, &getsockname);
+ dns_te_initname(remote, fd, &getpeername);
+}
+
+static struct dns_trace_event *dns_te_init(struct dns_trace_event *te, int type) {
+ /* NB: silence valgrind */
+ memset(te, '\0', offsetof(struct dns_trace_event, data));
+ te->type = type;
+ return te;
+}
+
+int dns_trace_abi(void) {
+ return DNS_TRACE_ABI;
+}
+
+struct dns_trace *dns_trace_open(FILE *fp, dns_error_t *error) {
+ static const struct dns_trace trace_initializer = { .refcount = 1 };
+ struct dns_trace *trace;
+
+ if (!(trace = malloc(sizeof *trace)))
+ goto syerr;
+
+ *trace = trace_initializer;
+
+ if (fp) {
+ trace->fp = fp;
+ } else if (!(fp = tmpfile())) {
+ goto syerr;
+ }
+
+ trace->id = dns_trace_mkid();
+
+ return trace;
+syerr:
+ *error = dns_syerr();
+
+ dns_trace_close(trace);
+
+ return NULL;
+} /* dns_trace_open() */
+
+void dns_trace_close(struct dns_trace *trace) {
+ if (!trace || 1 != dns_trace_release(trace))
+ return;
+
+ if (trace->fp)
+ fclose(trace->fp);
+ free(trace);
+} /* dns_trace_close() */
+
+dns_refcount_t dns_trace_acquire(struct dns_trace *trace) {
+ return dns_atomic_fetch_add(&trace->refcount);
+} /* dns_trace_acquire() */
+
+static struct dns_trace *dns_trace_acquire_p(struct dns_trace *trace) {
+ return (trace)? dns_trace_acquire(trace), trace : NULL;
+} /* dns_trace_acquire_p() */
+
+dns_refcount_t dns_trace_release(struct dns_trace *trace) {
+ return dns_atomic_fetch_sub(&trace->refcount);
+} /* dns_trace_release() */
+
+dns_trace_id_t dns_trace_id(struct dns_trace *trace) {
+ return trace->id;
+} /* dns_trace_id() */
+
+dns_trace_id_t dns_trace_setid(struct dns_trace *trace, dns_trace_id_t id) {
+ trace->id = (id)? id : dns_trace_mkid();
+ return trace->id;
+} /* dns_trace_setid() */
+
+struct dns_trace_event *dns_trace_get(struct dns_trace *trace, struct dns_trace_event **tp, dns_error_t *error) {
+ return dns_trace_fget(tp, trace->fp, error);
+} /* dns_trace_get() */
+
+dns_error_t dns_trace_put(struct dns_trace *trace, const struct dns_trace_event *te, const void *data, size_t datasize) {
+ return dns_trace_fput(te, data, datasize, trace->fp);
+} /* dns_trace_put() */
+
+struct dns_trace_event *dns_trace_tag(struct dns_trace *trace, struct dns_trace_event *te) {
+ struct timeval tv;
+
+ te->id = trace->id;
+ gettimeofday(&tv, NULL);
+ dns_tv2ts(&te->ts, &tv);
+ te->abi = DNS_TRACE_ABI;
+
+ return te;
+} /* dns_trace_tag() */
+
+static dns_error_t dns_trace_tag_and_put(struct dns_trace *trace, struct dns_trace_event *te, const void *data, size_t datasize) {
+ return dns_trace_put(trace, dns_trace_tag(trace, te), data, datasize);
+} /* dns_trace_tag_and_put() */
+
+struct dns_trace_event *dns_trace_fget(struct dns_trace_event **tp, FILE *fp, dns_error_t *error) {
+ const size_t headsize = offsetof(struct dns_trace_event, data);
+ struct dns_trace_event tmp, *te;
+ size_t n;
+
+ errno = 0;
+ if (!(n = fread(&tmp, 1, headsize, fp)))
+ goto none;
+ if (n < offsetof(struct dns_trace_event, data))
+ goto some;
+
+ if (!(te = realloc(*tp, DNS_PP_MAX(headsize, tmp.size)))) {
+ *error = errno;
+ return NULL;
+ }
+
+ *tp = te;
+ memcpy(te, &tmp, offsetof(struct dns_trace_event, data));
+
+ if (dns_te_datasize(te)) {
+ errno = 0;
+ if (!(n = fread(te->data, 1, dns_te_datasize(te), fp)))
+ goto none;
+ if (n < dns_te_datasize(te))
+ goto some;
+ }
+
+ return te;
+none:
+ *error = (ferror(fp))? errno : 0;
+ return NULL;
+some:
+ *error = 0;
+ return NULL;
+}
+
+dns_error_t dns_trace_fput(const struct dns_trace_event *te, const void *data, size_t datasize, FILE *fp) {
+ size_t headsize = offsetof(struct dns_trace_event, data);
+ struct dns_trace_event tmp;
+
+ memcpy(&tmp, te, headsize);
+ tmp.size = headsize + datasize;
+
+ /* NB: ignore seek error as fp might not point to a regular file */
+ (void)fseek(fp, 0, SEEK_END);
+
+ if (fwrite(&tmp, 1, headsize, fp) < headsize)
+ return errno;
+ if (fwrite(data, 1, datasize, fp) < datasize)
+ return errno;
+ if (fflush(fp))
+ return errno;
+
+ return 0;
+}
+
+static void dns_trace_setcname(struct dns_trace *trace, const char *host, const struct sockaddr *addr) {
+ if (!trace || !trace->fp)
+ return;
+
+ struct dns_trace_cname *cname = &trace->cnames.base[trace->cnames.p];
+ dns_strlcpy(cname->host, host, sizeof cname->host);
+ memcpy(&cname->addr, addr, DNS_PP_MIN(dns_sa_len(addr), sizeof cname->addr));
+
+ trace->cnames.p = (trace->cnames.p + 1) % lengthof(trace->cnames.base);
+}
+
+static const char *dns_trace_cname(struct dns_trace *trace, const struct sockaddr *addr) {
+ if (!trace || !trace->fp)
+ return NULL;
+
+ /* NB: start search from the write cursor to */
+ for (const struct dns_trace_cname *cname = trace->cnames.base; cname < endof(trace->cnames.base); cname++) {
+ if (0 == dns_sa_cmp((struct sockaddr *)addr, (struct sockaddr *)&cname->addr))
+ return cname->host;
+ }
+
+ return NULL;
+}
+
+static void dns_trace_res_submit(struct dns_trace *trace, const char *qname, enum dns_type qtype, enum dns_class qclass, int error) {
+ if (!trace || !trace->fp)
+ return;
+
+ struct dns_trace_event te;
+ dns_te_init(&te, DNS_TE_RES_SUBMIT);
+ dns_strlcpy(te.res_submit.qname, qname, sizeof te.res_submit.qname);
+ te.res_submit.qtype = qtype;
+ te.res_submit.qclass = qclass;
+ te.res_submit.error = error;
+ dns_trace_tag_and_put(trace, &te, NULL, 0);
+}
+
+static void dns_trace_res_fetch(struct dns_trace *trace, const struct dns_packet *packet, int error) {
+ if (!trace || !trace->fp)
+ return;
+
+ struct dns_trace_event te;
+ dns_te_init(&te, DNS_TE_RES_FETCH);
+ const void *data = (packet)? packet->data : NULL;
+ size_t datasize = (packet)? packet->end : 0;
+ te.res_fetch.error = error;
+ dns_trace_tag_and_put(trace, &te, data, datasize);
+}
+
+static void dns_trace_so_submit(struct dns_trace *trace, const struct dns_packet *packet, const struct sockaddr *haddr, int error) {
+ if (!trace || !trace->fp)
+ return;
+
+ struct dns_trace_event te;
+ dns_te_init(&te, DNS_TE_SO_SUBMIT);
+ memcpy(&te.so_submit.haddr, haddr, DNS_PP_MIN(dns_sa_len(haddr), sizeof te.so_submit.haddr));
+ const char *cname;
+ if ((cname = dns_trace_cname(trace, haddr)))
+ dns_strlcpy(te.so_submit.hname, cname, sizeof te.so_submit.hname);
+ te.so_submit.error = error;
+ dns_trace_tag_and_put(trace, &te, packet->data, packet->end);
+}
+
+static void dns_trace_so_verify(struct dns_trace *trace, const struct dns_packet *packet, int error) {
+ if (!trace || !trace->fp)
+ return;
+
+ struct dns_trace_event te;
+ dns_te_init(&te, DNS_TE_SO_VERIFY);
+ te.so_verify.error = error;
+ dns_trace_tag_and_put(trace, &te, packet->data, packet->end);
+}
+
+static void dns_trace_so_fetch(struct dns_trace *trace, const struct dns_packet *packet, int error) {
+ if (!trace || !trace->fp)
+ return;
+
+ struct dns_trace_event te;
+ dns_te_init(&te, DNS_TE_SO_FETCH);
+ const void *data = (packet)? packet->data : NULL;
+ size_t datasize = (packet)? packet->end : 0;
+ te.so_fetch.error = error;
+ dns_trace_tag_and_put(trace, &te, data, datasize);
+}
+
+static void dns_trace_sys_connect(struct dns_trace *trace, int fd, int socktype, const struct sockaddr *dst, int error) {
+ if (!trace || !trace->fp)
+ return;
+
+ struct dns_trace_event te;
+ dns_te_init(&te, DNS_TE_SYS_CONNECT);
+ dns_te_initname(&te.sys_connect.src, fd, &getsockname);
+ memcpy(&te.sys_connect.dst, dst, DNS_PP_MIN(dns_sa_len(dst), sizeof te.sys_connect.dst));
+ te.sys_connect.socktype = socktype;
+ te.sys_connect.error = error;
+ dns_trace_tag_and_put(trace, &te, NULL, 0);
+}
+
+static void dns_trace_sys_send(struct dns_trace *trace, int fd, int socktype, const void *data, size_t datasize, int error) {
+ if (!trace || !trace->fp)
+ return;
+
+ struct dns_trace_event te;
+ dns_te_init(&te, DNS_TE_SYS_SEND);
+ dns_te_initnames(&te.sys_send.src, &te.sys_send.dst, fd);
+ te.sys_send.socktype = socktype;
+ te.sys_send.error = error;
+ dns_trace_tag_and_put(trace, &te, data, datasize);
+}
+
+static void dns_trace_sys_recv(struct dns_trace *trace, int fd, int socktype, const void *data, size_t datasize, int error) {
+ if (!trace || !trace->fp)
+ return;
+
+ struct dns_trace_event te;
+ dns_te_init(&te, DNS_TE_SYS_RECV);
+ dns_te_initnames(&te.sys_recv.dst, &te.sys_recv.src, fd);
+ te.sys_recv.socktype = socktype;
+ te.sys_recv.error = error;
+ dns_trace_tag_and_put(trace, &te, data, datasize);
+}
+
+static dns_error_t dns_trace_dump_packet(struct dns_trace *trace, const char *prefix, const unsigned char *data, size_t datasize, FILE *fp) {
+ struct dns_packet *packet = NULL;
+ char *line = NULL, *p;
+ size_t size = 1, skip = 0;
+ int error;
+
+ if (!(packet = dns_p_make(datasize, &error)))
+ goto error;
+
+ memcpy(packet->data, data, datasize);
+ packet->end = datasize;
+ (void)dns_p_study(packet);
+resize:
+ if (!(p = dns_reallocarray(line, size, 2, &error)))
+ goto error;
+ line = p;
+ size *= 2;
+
+ struct dns_rr_i records = { 0 };
+ struct dns_p_lines_i lines = { 0 };
+ size_t len, count = 0;
+
+ while ((len = dns_p_lines(line, size, &error, packet, &records, &lines))) {
+ if (!(len < size)) {
+ skip = count;
+ goto resize;
+ } else if (skip <= count) {
+ fputs(prefix, fp);
+ fwrite(line, 1, len, fp);
+ }
+ count++;
+ }
+
+ if (error)
+ goto error;
+
+ error = 0;
+error:
+ free(line);
+ dns_p_free(packet);
+
+ return error;
+}
+
+static dns_error_t dns_trace_dump_data(struct dns_trace *trace, const char *prefix, const unsigned char *data, size_t datasize, FILE *fp) {
+ struct dns_hxd_lines_i lines = { 0 };
+ char line[128];
+ size_t len;
+
+ while ((len = dns_hxd_lines(line, sizeof line, data, datasize, &lines))) {
+ if (len >= sizeof line)
+ return EOVERFLOW; /* shouldn't be possible */
+ fputs(prefix, fp);
+ fwrite(line, 1, len, fp);
+ }
+
+ return 0;
+}
+
+static dns_error_t dns_trace_dump_addr(struct dns_trace *trace, const char *prefix, const struct sockaddr_storage *ss, FILE *fp) {
+ const void *addr;
+ const char *path;
+ socklen_t len;
+ int error;
+
+ if ((addr = dns_sa_addr(ss->ss_family, (struct sockaddr *)ss, NULL))) {
+ char ip[INET6_ADDRSTRLEN + 1];
+
+ if ((error = dns_ntop(ss->ss_family, addr, ip, sizeof ip)))
+ return error;
+ fprintf(fp, "%s%s\n", prefix, ip);
+ } else if ((path = dns_sa_path((struct sockaddr *)ss, &len))) {
+ fprintf(fp, "%sunix:%.*s", prefix, (int)len, path);
+ } else {
+ return EINVAL;
+ }
+
+ return 0;
+}
+
+static dns_error_t dns_trace_dump_meta(struct dns_trace *trace, const char *prefix, const struct dns_trace_event *te, dns_microseconds_t elapsed, FILE *fp) {
+ char time_s[48], elapsed_s[48];
+
+ dns_utime_print(time_s, sizeof time_s, dns_ts2us(&te->ts, 0));
+ dns_utime_print(elapsed_s, sizeof elapsed_s, elapsed);
+
+ fprintf(fp, "%sid: %"DNS_TRACE_ID_PRI"\n", prefix, te->id);
+ fprintf(fp, "%sts: %s (%s)\n", prefix, time_s, elapsed_s);
+ fprintf(fp, "%sabi: 0x%x (0x%x)\n", prefix, te->abi, DNS_TRACE_ABI);
+ return 0;
+}
+
+static dns_error_t dns_trace_dump_error(struct dns_trace *trace, const char *prefix, int error, FILE *fp) {
+ fprintf(fp, "%s%d (%s)\n", prefix, error, (error)? dns_strerror(error) : "none");
+ return 0;
+}
+
+dns_error_t dns_trace_dump(struct dns_trace *trace, FILE *fp) {
+ struct dns_trace_event *te = NULL;
+ struct {
+ dns_trace_id_t id;
+ dns_microseconds_t begin, elapsed;
+ } state = { 0 };
+ int error;
+
+ if (!trace || !trace->fp)
+ return EINVAL;
+
+ if (0 != fseek(trace->fp, 0, SEEK_SET))
+ goto syerr;
+
+ while (dns_trace_fget(&te, trace->fp, &error)) {
+ size_t datasize = dns_te_datasize(te);
+ const unsigned char *data = (datasize)? te->data : NULL;
+
+ if (state.id != te->id) {
+ state.id = te->id;
+ state.begin = dns_ts2us(&te->ts, 0);
+ }
+ dns_time_diff(&state.elapsed, dns_ts2us(&te->ts, 0), state.begin);
+
+ switch(te->type) {
+ case DNS_TE_RES_SUBMIT:
+ fprintf(fp, "dns_res_submit:\n");
+ dns_trace_dump_meta(trace, " ", te, state.elapsed, fp);
+ fprintf(fp, " qname: %s\n", te->res_submit.qname);
+ fprintf(fp, " qtype: %s\n", dns_strtype(te->res_submit.qtype));
+ fprintf(fp, " qclass: %s\n", dns_strclass(te->res_submit.qclass));
+ dns_trace_dump_error(trace, " error: ", te->res_submit.error, fp);
+ break;
+ case DNS_TE_RES_FETCH:
+ fprintf(fp, "dns_res_fetch:\n");
+ dns_trace_dump_meta(trace, " ", te, state.elapsed, fp);
+ dns_trace_dump_error(trace, " error: ", te->res_fetch.error, fp);
+
+ if (data) {
+ fprintf(fp, " packet: |\n");
+ if ((error = dns_trace_dump_packet(trace, " ", data, datasize, fp)))
+ goto error;
+ fprintf(fp, " data: |\n");
+ if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp)))
+ goto error;
+ }
+
+ break;
+ case DNS_TE_SO_SUBMIT:
+ fprintf(fp, "dns_so_submit:\n");
+ dns_trace_dump_meta(trace, " ", te, state.elapsed, fp);
+ fprintf(fp, " hname: %s\n", te->so_submit.hname);
+ dns_trace_dump_addr(trace, " haddr: ", &te->so_submit.haddr, fp);
+ dns_trace_dump_error(trace, " error: ", te->so_submit.error, fp);
+
+ if (data) {
+ fprintf(fp, " packet: |\n");
+ if ((error = dns_trace_dump_packet(trace, " ", data, datasize, fp)))
+ goto error;
+ fprintf(fp, " data: |\n");
+ if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp)))
+ goto error;
+ }
+
+ break;
+ case DNS_TE_SO_VERIFY:
+ fprintf(fp, "dns_so_verify:\n");
+ dns_trace_dump_meta(trace, " ", te, state.elapsed, fp);
+ dns_trace_dump_error(trace, " error: ", te->so_verify.error, fp);
+
+ if (data) {
+ fprintf(fp, " packet: |\n");
+ if ((error = dns_trace_dump_packet(trace, " ", data, datasize, fp)))
+ goto error;
+ fprintf(fp, " data: |\n");
+ if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp)))
+ goto error;
+ }
+
+ break;
+ case DNS_TE_SO_FETCH:
+ fprintf(fp, "dns_so_fetch:\n");
+ dns_trace_dump_meta(trace, " ", te, state.elapsed, fp);
+ dns_trace_dump_error(trace, " error: ", te->so_fetch.error, fp);
+
+ if (data) {
+ fprintf(fp, " packet: |\n");
+ if ((error = dns_trace_dump_packet(trace, " ", data, datasize, fp)))
+ goto error;
+ fprintf(fp, " data: |\n");
+ if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp)))
+ goto error;
+ }
+
+ break;
+ case DNS_TE_SYS_CONNECT: {
+ fprintf(fp, "dns_sys_connect:\n");
+ dns_trace_dump_meta(trace, " ", te, state.elapsed, fp);
+ dns_trace_dump_addr(trace, " src: ", &te->sys_connect.src, fp);
+ dns_trace_dump_addr(trace, " dst: ", &te->sys_connect.dst, fp);
+ int socktype = te->sys_connect.socktype;
+ fprintf(fp, " socktype: %d (%s)\n", socktype, ((socktype == SOCK_STREAM)? "SOCK_STREAM" : (socktype == SOCK_DGRAM)? "SOCK_DGRAM" : "?"));
+ dns_trace_dump_error(trace, " error: ", te->sys_connect.error, fp);
+
+ break;
+ }
+ case DNS_TE_SYS_SEND: {
+ fprintf(fp, "dns_sys_send:\n");
+ dns_trace_dump_meta(trace, " ", te, state.elapsed, fp);
+ dns_trace_dump_addr(trace, " src: ", &te->sys_send.src, fp);
+ dns_trace_dump_addr(trace, " dst: ", &te->sys_send.dst, fp);
+ int socktype = te->sys_send.socktype;
+ fprintf(fp, " socktype: %d (%s)\n", socktype, ((socktype == SOCK_STREAM)? "SOCK_STREAM" : (socktype == SOCK_DGRAM)? "SOCK_DGRAM" : "?"));
+ dns_trace_dump_error(trace, " error: ", te->sys_send.error, fp);
+
+ if (data) {
+ fprintf(fp, " data: |\n");
+ if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp)))
+ goto error;
+ }
+
+ break;
+ }
+ case DNS_TE_SYS_RECV: {
+ fprintf(fp, "dns_sys_recv:\n");
+ dns_trace_dump_meta(trace, " ", te, state.elapsed, fp);
+ dns_trace_dump_addr(trace, " src: ", &te->sys_recv.src, fp);
+ dns_trace_dump_addr(trace, " dst: ", &te->sys_recv.dst, fp);
+ int socktype = te->sys_recv.socktype;
+ fprintf(fp, " socktype: %d (%s)\n", socktype, ((socktype == SOCK_STREAM)? "SOCK_STREAM" : (socktype == SOCK_DGRAM)? "SOCK_DGRAM" : "?"));
+ dns_trace_dump_error(trace, " error: ", te->sys_recv.error, fp);
+
+ if (data) {
+ fprintf(fp, " data: |\n");
+ if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp)))
+ goto error;
+ }
+
+ break;
+ }
+ default:
+ fprintf(fp, "unknown(0x%.2x):\n", te->type);
+ dns_trace_dump_meta(trace, " ", te, state.elapsed, fp);
+
+ if (data) {
+ fprintf(fp, " data: |\n");
+ if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp)))
+ goto error;
+ }
+
+ break;
+ }
+ }
+
+ goto epilog;
+syerr:
+ error = errno;
+error:
+ (void)0;
+epilog:
+ free(te);
+
+ return error;
+}
+
+/*
+ * H O S T S R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_hosts {
+ struct dns_hosts_entry {
+ char host[DNS_D_MAXNAME + 1];
+ char arpa[73 + 1];
+
+ int af;
+
+ union {
+ struct in_addr a4;
+ struct in6_addr a6;
+ } addr;
+
+ _Bool alias;
+
+ struct dns_hosts_entry *next;
+ } *head, **tail;
+
+ dns_atomic_t refcount;
+}; /* struct dns_hosts */
+
+
+struct dns_hosts *dns_hosts_open(int *error) {
+ static const struct dns_hosts hosts_initializer = { .refcount = 1 };
+ struct dns_hosts *hosts;
+
+ if (!(hosts = malloc(sizeof *hosts)))
+ goto syerr;
+
+ *hosts = hosts_initializer;
+
+ hosts->tail = &hosts->head;
+
+ return hosts;
+syerr:
+ *error = dns_syerr();
+
+ free(hosts);
+
+ return 0;
+} /* dns_hosts_open() */
+
+
+void dns_hosts_close(struct dns_hosts *hosts) {
+ struct dns_hosts_entry *ent, *xnt;
+
+ if (!hosts || 1 != dns_hosts_release(hosts))
+ return;
+
+ for (ent = hosts->head; ent; ent = xnt) {
+ xnt = ent->next;
+
+ free(ent);
+ }
+
+ free(hosts);
+
+ return;
+} /* dns_hosts_close() */
+
+
+dns_refcount_t dns_hosts_acquire(struct dns_hosts *hosts) {
+ return dns_atomic_fetch_add(&hosts->refcount);
+} /* dns_hosts_acquire() */
+
+
+dns_refcount_t dns_hosts_release(struct dns_hosts *hosts) {
+ return dns_atomic_fetch_sub(&hosts->refcount);
+} /* dns_hosts_release() */
+
+
+struct dns_hosts *dns_hosts_mortal(struct dns_hosts *hosts) {
+ if (hosts)
+ dns_hosts_release(hosts);
+
+ return hosts;
+} /* dns_hosts_mortal() */
+
+
+struct dns_hosts *dns_hosts_local(int *error_) {
+ struct dns_hosts *hosts;
+ int error;
+
+ if (!(hosts = dns_hosts_open(&error)))
+ goto error;
+
+ if ((error = dns_hosts_loadpath(hosts, "/etc/hosts")))
+ goto error;
+
+ return hosts;
+error:
+ *error_ = error;
+
+ dns_hosts_close(hosts);
+
+ return 0;
+} /* dns_hosts_local() */
+
+
+#define dns_hosts_issep(ch) (dns_isspace(ch))
+#define dns_hosts_iscom(ch) ((ch) == '#' || (ch) == ';')
+
+int dns_hosts_loadfile(struct dns_hosts *hosts, FILE *fp) {
+ struct dns_hosts_entry ent;
+ char word[DNS_PP_MAX(INET6_ADDRSTRLEN, DNS_D_MAXNAME) + 1];
+ unsigned wp, wc, skip;
+ int ch, error;
+
+ rewind(fp);
+
+ do {
+ memset(&ent, '\0', sizeof ent);
+ wc = 0;
+ skip = 0;
+
+ do {
+ memset(word, '\0', sizeof word);
+ wp = 0;
+
+ while (EOF != (ch = fgetc(fp)) && ch != '\n') {
+ skip |= !!dns_hosts_iscom(ch);
+
+ if (skip)
+ continue;
+
+ if (dns_hosts_issep(ch))
+ break;
+
+ if (wp < sizeof word - 1)
+ word[wp] = ch;
+ wp++;
+ }
+
+ if (!wp)
+ continue;
+
+ wc++;
+
+ switch (wc) {
+ case 0:
+ break;
+ case 1:
+ ent.af = (strchr(word, ':'))? AF_INET6 : AF_INET;
+ skip = (1 != dns_inet_pton(ent.af, word, &ent.addr));
+
+ break;
+ default:
+ if (!wp)
+ break;
+
+ dns_d_anchor(ent.host, sizeof ent.host, word, wp);
+
+ if ((error = dns_hosts_insert(hosts, ent.af, &ent.addr, ent.host, (wc > 2))))
+ return error;
+
+ break;
+ } /* switch() */
+ } while (ch != EOF && ch != '\n');
+ } while (ch != EOF);
+
+ return 0;
+} /* dns_hosts_loadfile() */
+
+
+int dns_hosts_loadpath(struct dns_hosts *hosts, const char *path) {
+ FILE *fp;
+ int error;
+
+ if (!(fp = dns_fopen(path, "rt", &error)))
+ return error;
+
+ error = dns_hosts_loadfile(hosts, fp);
+
+ fclose(fp);
+
+ return error;
+} /* dns_hosts_loadpath() */
+
+
+int dns_hosts_dump(struct dns_hosts *hosts, FILE *fp) {
+ struct dns_hosts_entry *ent, *xnt;
+ char addr[INET6_ADDRSTRLEN + 1];
+ unsigned i;
+
+ for (ent = hosts->head; ent; ent = xnt) {
+ xnt = ent->next;
+
+ dns_inet_ntop(ent->af, &ent->addr, addr, sizeof addr);
+
+ fputs(addr, fp);
+
+ for (i = strlen(addr); i < INET_ADDRSTRLEN; i++)
+ fputc(' ', fp);
+
+ fputc(' ', fp);
+
+ fputs(ent->host, fp);
+ fputc('\n', fp);
+ }
+
+ return 0;
+} /* dns_hosts_dump() */
+
+
+int dns_hosts_insert(struct dns_hosts *hosts, int af, const void *addr, const void *host, _Bool alias) {
+ struct dns_hosts_entry *ent;
+ int error;
+
+ if (!(ent = malloc(sizeof *ent)))
+ goto syerr;
+
+ dns_d_anchor(ent->host, sizeof ent->host, host, strlen(host));
+
+ switch ((ent->af = af)) {
+ case AF_INET6:
+ memcpy(&ent->addr.a6, addr, sizeof ent->addr.a6);
+
+ dns_aaaa_arpa(ent->arpa, sizeof ent->arpa, addr);
+
+ break;
+ case AF_INET:
+ memcpy(&ent->addr.a4, addr, sizeof ent->addr.a4);
+
+ dns_a_arpa(ent->arpa, sizeof ent->arpa, addr);
+
+ break;
+ default:
+ error = EINVAL;
+
+ goto error;
+ } /* switch() */
+
+ ent->alias = alias;
+
+ ent->next = 0;
+ *hosts->tail = ent;
+ hosts->tail = &ent->next;
+
+ return 0;
+syerr:
+ error = dns_syerr();
+error:
+ free(ent);
+
+ return error;
+} /* dns_hosts_insert() */
+
+
+struct dns_packet *dns_hosts_query(struct dns_hosts *hosts, struct dns_packet *Q, int *error_) {
+ struct dns_packet *P = dns_p_new(512);
+ struct dns_packet *A = 0;
+ struct dns_rr rr;
+ struct dns_hosts_entry *ent;
+ int error, af;
+ char qname[DNS_D_MAXNAME + 1];
+ size_t qlen;
+
+ if ((error = dns_rr_parse(&rr, 12, Q)))
+ goto error;
+
+ if (!(qlen = dns_d_expand(qname, sizeof qname, rr.dn.p, Q, &error)))
+ goto error;
+ else if (qlen >= sizeof qname)
+ goto toolong;
+
+ if ((error = dns_p_push(P, DNS_S_QD, qname, qlen, rr.type, rr.class, 0, 0)))
+ goto error;
+
+ switch (rr.type) {
+ case DNS_T_PTR:
+ for (ent = hosts->head; ent; ent = ent->next) {
+ if (ent->alias || 0 != strcasecmp(qname, ent->arpa))
+ continue;
+
+ if ((error = dns_p_push(P, DNS_S_AN, qname, qlen, rr.type, rr.class, 0, ent->host)))
+ goto error;
+ }
+
+ break;
+ case DNS_T_AAAA:
+ af = AF_INET6;
+
+ goto loop;
+ case DNS_T_A:
+ af = AF_INET;
+
+loop: for (ent = hosts->head; ent; ent = ent->next) {
+ if (ent->af != af || 0 != strcasecmp(qname, ent->host))
+ continue;
+
+ if ((error = dns_p_push(P, DNS_S_AN, qname, qlen, rr.type, rr.class, 0, &ent->addr)))
+ goto error;
+ }
+
+ break;
+ default:
+ break;
+ } /* switch() */
+
+
+ if (!(A = dns_p_copy(dns_p_make(P->end, &error), P)))
+ goto error;
+
+ return A;
+toolong:
+ error = DNS_EILLEGAL;
+error:
+ *error_ = error;
+
+ dns_p_free(A);
+
+ return 0;
+} /* dns_hosts_query() */
+
+
+/*
+ * R E S O L V . C O N F R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_resolv_conf *dns_resconf_open(int *error) {
+ static const struct dns_resolv_conf resconf_initializer = {
+ .lookup = "bf",
+ .family = { AF_INET, AF_INET6 },
+ .options = { .ndots = 1, .timeout = 5, .attempts = 2, .tcp = DNS_RESCONF_TCP_ENABLE, },
+ .iface = { .ss_family = AF_INET },
+ };
+ struct dns_resolv_conf *resconf;
+ struct sockaddr_in *sin;
+
+ if (!(resconf = malloc(sizeof *resconf)))
+ goto syerr;
+
+ *resconf = resconf_initializer;
+
+ sin = (struct sockaddr_in *)&resconf->nameserver[0];
+ sin->sin_family = AF_INET;
+ sin->sin_addr.s_addr = INADDR_ANY;
+ sin->sin_port = htons(53);
+#if defined(SA_LEN)
+ sin->sin_len = sizeof *sin;
+#endif
+
+ if (0 != gethostname(resconf->search[0], sizeof resconf->search[0]))
+ goto syerr;
+
+ dns_d_anchor(resconf->search[0], sizeof resconf->search[0], resconf->search[0], strlen(resconf->search[0]));
+ dns_d_cleave(resconf->search[0], sizeof resconf->search[0], resconf->search[0], strlen(resconf->search[0]));
+
+ /*
+ * XXX: If gethostname() returned a string without any label
+ * separator, then search[0][0] should be NUL.
+ */
+
+ dns_resconf_acquire(resconf);
+
+ return resconf;
+syerr:
+ *error = dns_syerr();
+
+ free(resconf);
+
+ return 0;
+} /* dns_resconf_open() */
+
+
+void dns_resconf_close(struct dns_resolv_conf *resconf) {
+ if (!resconf || 1 != dns_resconf_release(resconf))
+ return /* void */;
+
+ free(resconf);
+} /* dns_resconf_close() */
+
+
+dns_refcount_t dns_resconf_acquire(struct dns_resolv_conf *resconf) {
+ return dns_atomic_fetch_add(&resconf->_.refcount);
+} /* dns_resconf_acquire() */
+
+
+dns_refcount_t dns_resconf_release(struct dns_resolv_conf *resconf) {
+ return dns_atomic_fetch_sub(&resconf->_.refcount);
+} /* dns_resconf_release() */
+
+
+struct dns_resolv_conf *dns_resconf_mortal(struct dns_resolv_conf *resconf) {
+ if (resconf)
+ dns_resconf_release(resconf);
+
+ return resconf;
+} /* dns_resconf_mortal() */
+
+
+struct dns_resolv_conf *dns_resconf_local(int *error_) {
+ struct dns_resolv_conf *resconf;
+ int error;
+
+ if (!(resconf = dns_resconf_open(&error)))
+ goto error;
+
+ if ((error = dns_resconf_loadpath(resconf, "/etc/resolv.conf"))) {
+ /*
+ * NOTE: Both the glibc and BIND9 resolvers ignore a missing
+ * /etc/resolv.conf, defaulting to a nameserver of
+ * 127.0.0.1. See also dns_hints_insert_resconf, and the
+ * default initialization of nameserver[0] in
+ * dns_resconf_open.
+ */
+ if (error != ENOENT)
+ goto error;
+ }
+
+ if ((error = dns_nssconf_loadpath(resconf, "/etc/nsswitch.conf"))) {
+ if (error != ENOENT)
+ goto error;
+ }
+
+ return resconf;
+error:
+ *error_ = error;
+
+ dns_resconf_close(resconf);
+
+ return 0;
+} /* dns_resconf_local() */
+
+
+struct dns_resolv_conf *dns_resconf_root(int *error) {
+ struct dns_resolv_conf *resconf;
+
+ if ((resconf = dns_resconf_local(error)))
+ resconf->options.recurse = 1;
+
+ return resconf;
+} /* dns_resconf_root() */
+
+
+static time_t dns_resconf_timeout(const struct dns_resolv_conf *resconf) {
+ return (time_t)DNS_PP_MIN(INT_MAX, resconf->options.timeout);
+} /* dns_resconf_timeout() */
+
+
+enum dns_resconf_keyword {
+ DNS_RESCONF_NAMESERVER,
+ DNS_RESCONF_DOMAIN,
+ DNS_RESCONF_SEARCH,
+ DNS_RESCONF_LOOKUP,
+ DNS_RESCONF_FILE,
+ DNS_RESCONF_BIND,
+ DNS_RESCONF_CACHE,
+ DNS_RESCONF_FAMILY,
+ DNS_RESCONF_INET4,
+ DNS_RESCONF_INET6,
+ DNS_RESCONF_OPTIONS,
+ DNS_RESCONF_EDNS0,
+ DNS_RESCONF_NDOTS,
+ DNS_RESCONF_TIMEOUT,
+ DNS_RESCONF_ATTEMPTS,
+ DNS_RESCONF_ROTATE,
+ DNS_RESCONF_RECURSE,
+ DNS_RESCONF_SMART,
+ DNS_RESCONF_TCP,
+ DNS_RESCONF_TCPx,
+ DNS_RESCONF_INTERFACE,
+ DNS_RESCONF_ZERO,
+ DNS_RESCONF_ONE,
+ DNS_RESCONF_ENABLE,
+ DNS_RESCONF_ONLY,
+ DNS_RESCONF_DISABLE,
+}; /* enum dns_resconf_keyword */
+
+static enum dns_resconf_keyword dns_resconf_keyword(const char *word) {
+ static const char *words[] = {
+ [DNS_RESCONF_NAMESERVER] = "nameserver",
+ [DNS_RESCONF_DOMAIN] = "domain",
+ [DNS_RESCONF_SEARCH] = "search",
+ [DNS_RESCONF_LOOKUP] = "lookup",
+ [DNS_RESCONF_FILE] = "file",
+ [DNS_RESCONF_BIND] = "bind",
+ [DNS_RESCONF_CACHE] = "cache",
+ [DNS_RESCONF_FAMILY] = "family",
+ [DNS_RESCONF_INET4] = "inet4",
+ [DNS_RESCONF_INET6] = "inet6",
+ [DNS_RESCONF_OPTIONS] = "options",
+ [DNS_RESCONF_EDNS0] = "edns0",
+ [DNS_RESCONF_ROTATE] = "rotate",
+ [DNS_RESCONF_RECURSE] = "recurse",
+ [DNS_RESCONF_SMART] = "smart",
+ [DNS_RESCONF_TCP] = "tcp",
+ [DNS_RESCONF_INTERFACE] = "interface",
+ [DNS_RESCONF_ZERO] = "0",
+ [DNS_RESCONF_ONE] = "1",
+ [DNS_RESCONF_ENABLE] = "enable",
+ [DNS_RESCONF_ONLY] = "only",
+ [DNS_RESCONF_DISABLE] = "disable",
+ };
+ unsigned i;
+
+ for (i = 0; i < lengthof(words); i++) {
+ if (words[i] && 0 == strcasecmp(words[i], word))
+ return i;
+ }
+
+ if (0 == strncasecmp(word, "ndots:", sizeof "ndots:" - 1))
+ return DNS_RESCONF_NDOTS;
+
+ if (0 == strncasecmp(word, "timeout:", sizeof "timeout:" - 1))
+ return DNS_RESCONF_TIMEOUT;
+
+ if (0 == strncasecmp(word, "attempts:", sizeof "attempts:" - 1))
+ return DNS_RESCONF_ATTEMPTS;
+
+ if (0 == strncasecmp(word, "tcp:", sizeof "tcp:" - 1))
+ return DNS_RESCONF_TCPx;
+
+ return -1;
+} /* dns_resconf_keyword() */
+
+
+/** OpenBSD-style "[1.2.3.4]:53" nameserver syntax */
+int dns_resconf_pton(struct sockaddr_storage *ss, const char *src) {
+ struct { char buf[128], *p; } addr = { "", addr.buf };
+ unsigned short port = 0;
+ int ch, af = AF_INET, error;
+
+ while ((ch = *src++)) {
+ switch (ch) {
+ case ' ':
+ /* FALL THROUGH */
+ case '\t':
+ break;
+ case '[':
+ break;
+ case ']':
+ while ((ch = *src++)) {
+ if (dns_isdigit(ch)) {
+ port *= 10;
+ port += ch - '0';
+ }
+ }
+
+ goto inet;
+ case ':':
+ af = AF_INET6;
+
+ /* FALL THROUGH */
+ default:
+ if (addr.p < endof(addr.buf) - 1)
+ *addr.p++ = ch;
+
+ break;
+ } /* switch() */
+ } /* while() */
+inet:
+
+ if ((error = dns_pton(af, addr.buf, dns_sa_addr(af, ss, NULL))))
+ return error;
+
+ port = (!port)? 53 : port;
+ *dns_sa_port(af, ss) = htons(port);
+ dns_sa_family(ss) = af;
+
+ return 0;
+} /* dns_resconf_pton() */
+
+#define dns_resconf_issep(ch) (dns_isspace(ch) || (ch) == ',')
+#define dns_resconf_iscom(ch) ((ch) == '#' || (ch) == ';')
+
+int dns_resconf_loadfile(struct dns_resolv_conf *resconf, FILE *fp) {
+ unsigned sa_count = 0;
+ char words[6][DNS_D_MAXNAME + 1];
+ unsigned wp, wc, i, j, n;
+ int ch, error;
+
+ rewind(fp);
+
+ do {
+ memset(words, '\0', sizeof words);
+ wp = 0;
+ wc = 0;
+
+ while (EOF != (ch = getc(fp)) && ch != '\n') {
+ if (dns_resconf_issep(ch)) {
+ if (wp > 0) {
+ wp = 0;
+
+ if (++wc >= lengthof(words))
+ goto skip;
+ }
+ } else if (dns_resconf_iscom(ch)) {
+skip:
+ do {
+ ch = getc(fp);
+ } while (ch != EOF && ch != '\n');
+
+ break;
+ } else if (wp < sizeof words[wc] - 1) {
+ words[wc][wp++] = ch;
+ } else {
+ wp = 0; /* drop word */
+ goto skip;
+ }
+ }
+
+ if (wp > 0)
+ wc++;
+
+ if (wc < 2)
+ continue;
+
+ switch (dns_resconf_keyword(words[0])) {
+ case DNS_RESCONF_NAMESERVER:
+ if (sa_count >= lengthof(resconf->nameserver))
+ continue;
+
+ if ((error = dns_resconf_pton(&resconf->nameserver[sa_count], words[1])))
+ continue;
+
+ sa_count++;
+
+ break;
+ case DNS_RESCONF_DOMAIN:
+ case DNS_RESCONF_SEARCH:
+ memset(resconf->search, '\0', sizeof resconf->search);
+
+ for (i = 1, j = 0; i < wc && j < lengthof(resconf->search); i++, j++)
+ dns_d_anchor(resconf->search[j], sizeof resconf->search[j], words[i], strlen(words[i]));
+
+ break;
+ case DNS_RESCONF_LOOKUP:
+ for (i = 1, j = 0; i < wc && j < lengthof(resconf->lookup); i++) {
+ switch (dns_resconf_keyword(words[i])) {
+ case DNS_RESCONF_FILE:
+ resconf->lookup[j++] = 'f';
+
+ break;
+ case DNS_RESCONF_BIND:
+ resconf->lookup[j++] = 'b';
+
+ break;
+ case DNS_RESCONF_CACHE:
+ resconf->lookup[j++] = 'c';
+
+ break;
+ default:
+ break;
+ } /* switch() */
+ } /* for() */
+
+ break;
+ case DNS_RESCONF_FAMILY:
+ for (i = 1, j = 0; i < wc && j < lengthof(resconf->family); i++) {
+ switch (dns_resconf_keyword(words[i])) {
+ case DNS_RESCONF_INET4:
+ resconf->family[j++] = AF_INET;
+
+ break;
+ case DNS_RESCONF_INET6:
+ resconf->family[j++] = AF_INET6;
+
+ break;
+ default:
+ break;
+ }
+ }
+
+ break;
+ case DNS_RESCONF_OPTIONS:
+ for (i = 1; i < wc; i++) {
+ switch (dns_resconf_keyword(words[i])) {
+ case DNS_RESCONF_EDNS0:
+ resconf->options.edns0 = 1;
+
+ break;
+ case DNS_RESCONF_NDOTS:
+ for (j = sizeof "ndots:" - 1, n = 0; dns_isdigit(words[i][j]); j++) {
+ n *= 10;
+ n += words[i][j] - '0';
+ } /* for() */
+
+ resconf->options.ndots = n;
+
+ break;
+ case DNS_RESCONF_TIMEOUT:
+ for (j = sizeof "timeout:" - 1, n = 0; dns_isdigit(words[i][j]); j++) {
+ n *= 10;
+ n += words[i][j] - '0';
+ } /* for() */
+
+ resconf->options.timeout = n;
+
+ break;
+ case DNS_RESCONF_ATTEMPTS:
+ for (j = sizeof "attempts:" - 1, n = 0; dns_isdigit(words[i][j]); j++) {
+ n *= 10;
+ n += words[i][j] - '0';
+ } /* for() */
+
+ resconf->options.attempts = n;
+
+ break;
+ case DNS_RESCONF_ROTATE:
+ resconf->options.rotate = 1;
+
+ break;
+ case DNS_RESCONF_RECURSE:
+ resconf->options.recurse = 1;
+
+ break;
+ case DNS_RESCONF_SMART:
+ resconf->options.smart = 1;
+
+ break;
+ case DNS_RESCONF_TCP:
+ resconf->options.tcp = DNS_RESCONF_TCP_ONLY;
+
+ break;
+ case DNS_RESCONF_TCPx:
+ switch (dns_resconf_keyword(&words[i][sizeof "tcp:" - 1])) {
+ case DNS_RESCONF_ENABLE:
+ resconf->options.tcp = DNS_RESCONF_TCP_ENABLE;
+
+ break;
+ case DNS_RESCONF_ONE:
+ case DNS_RESCONF_ONLY:
+ resconf->options.tcp = DNS_RESCONF_TCP_ONLY;
+
+ break;
+ case DNS_RESCONF_ZERO:
+ case DNS_RESCONF_DISABLE:
+ resconf->options.tcp = DNS_RESCONF_TCP_DISABLE;
+
+ break;
+ default:
+ break;
+ } /* switch() */
+
+ break;
+ default:
+ break;
+ } /* switch() */
+ } /* for() */
+
+ break;
+ case DNS_RESCONF_INTERFACE:
+ for (i = 0, n = 0; dns_isdigit(words[2][i]); i++) {
+ n *= 10;
+ n += words[2][i] - '0';
+ }
+
+ dns_resconf_setiface(resconf, words[1], n);
+
+ break;
+ default:
+ break;
+ } /* switch() */
+ } while (ch != EOF);
+
+ return 0;
+} /* dns_resconf_loadfile() */
+
+
+int dns_resconf_loadpath(struct dns_resolv_conf *resconf, const char *path) {
+ FILE *fp;
+ int error;
+
+ if (!(fp = dns_fopen(path, "rt", &error)))
+ return error;
+
+ error = dns_resconf_loadfile(resconf, fp);
+
+ fclose(fp);
+
+ return error;
+} /* dns_resconf_loadpath() */
+
+
+struct dns_anyconf {
+ char *token[16];
+ unsigned count;
+ char buffer[1024], *tp, *cp;
+}; /* struct dns_anyconf */
+
+
+static void dns_anyconf_reset(struct dns_anyconf *cf) {
+ cf->count = 0;
+ cf->tp = cf->cp = cf->buffer;
+} /* dns_anyconf_reset() */
+
+
+static int dns_anyconf_push(struct dns_anyconf *cf) {
+ if (!(cf->cp < endof(cf->buffer) && cf->count < lengthof(cf->token)))
+ return ENOMEM;
+
+ *cf->cp++ = '\0';
+ cf->token[cf->count++] = cf->tp;
+ cf->tp = cf->cp;
+
+ return 0;
+} /* dns_anyconf_push() */
+
+
+static void dns_anyconf_pop(struct dns_anyconf *cf) {
+ if (cf->count > 0) {
+ --cf->count;
+ cf->tp = cf->cp = cf->token[cf->count];
+ cf->token[cf->count] = 0;
+ }
+} /* dns_anyconf_pop() */
+
+
+static int dns_anyconf_addc(struct dns_anyconf *cf, int ch) {
+ if (!(cf->cp < endof(cf->buffer)))
+ return ENOMEM;
+
+ *cf->cp++ = ch;
+
+ return 0;
+} /* dns_anyconf_addc() */
+
+
+static _Bool dns_anyconf_match(const char *pat, int mc) {
+ _Bool match;
+ int pc;
+
+ if (*pat == '^') {
+ match = 0;
+ ++pat;
+ } else {
+ match = 1;
+ }
+
+ while ((pc = *(const unsigned char *)pat++)) {
+ switch (pc) {
+ case '%':
+ if (!(pc = *(const unsigned char *)pat++))
+ return !match;
+
+ switch (pc) {
+ case 'a':
+ if (dns_isalpha(mc))
+ return match;
+ break;
+ case 'd':
+ if (dns_isdigit(mc))
+ return match;
+ break;
+ case 'w':
+ if (dns_isalnum(mc))
+ return match;
+ break;
+ case 's':
+ if (dns_isspace(mc))
+ return match;
+ break;
+ default:
+ if (mc == pc)
+ return match;
+ break;
+ } /* switch() */
+
+ break;
+ default:
+ if (mc == pc)
+ return match;
+ break;
+ } /* switch() */
+ } /* while() */
+
+ return !match;
+} /* dns_anyconf_match() */
+
+
+static int dns_anyconf_peek(FILE *fp) {
+ int ch;
+ ch = getc(fp);
+ ungetc(ch, fp);
+ return ch;
+} /* dns_anyconf_peek() */
+
+
+static size_t dns_anyconf_skip(const char *pat, FILE *fp) {
+ size_t count = 0;
+ int ch;
+
+ while (EOF != (ch = getc(fp))) {
+ if (dns_anyconf_match(pat, ch)) {
+ count++;
+ continue;
+ }
+
+ ungetc(ch, fp);
+
+ break;
+ }
+
+ return count;
+} /* dns_anyconf_skip() */
+
+
+static size_t dns_anyconf_scan(struct dns_anyconf *cf, const char *pat, FILE *fp, int *error) {
+ size_t len;
+ int ch;
+
+ while (EOF != (ch = getc(fp))) {
+ if (dns_anyconf_match(pat, ch)) {
+ if ((*error = dns_anyconf_addc(cf, ch)))
+ return 0;
+
+ continue;
+ } else {
+ ungetc(ch, fp);
+
+ break;
+ }
+ }
+
+ if ((len = cf->cp - cf->tp)) {
+ if ((*error = dns_anyconf_push(cf)))
+ return 0;
+
+ return len;
+ } else {
+ *error = 0;
+
+ return 0;
+ }
+} /* dns_anyconf_scan() */
+
+
+DNS_NOTUSED static void dns_anyconf_dump(struct dns_anyconf *cf, FILE *fp) {
+ unsigned i;
+
+ fprintf(fp, "tokens:");
+
+ for (i = 0; i < cf->count; i++) {
+ fprintf(fp, " %s", cf->token[i]);
+ }
+
+ fputc('\n', fp);
+} /* dns_anyconf_dump() */
+
+
+enum dns_nssconf_keyword {
+ DNS_NSSCONF_INVALID = 0,
+ DNS_NSSCONF_HOSTS = 1,
+ DNS_NSSCONF_SUCCESS,
+ DNS_NSSCONF_NOTFOUND,
+ DNS_NSSCONF_UNAVAIL,
+ DNS_NSSCONF_TRYAGAIN,
+ DNS_NSSCONF_CONTINUE,
+ DNS_NSSCONF_RETURN,
+ DNS_NSSCONF_FILES,
+ DNS_NSSCONF_DNS,
+ DNS_NSSCONF_MDNS,
+
+ DNS_NSSCONF_LAST,
+}; /* enum dns_nssconf_keyword */
+
+static enum dns_nssconf_keyword dns_nssconf_keyword(const char *word) {
+ static const char *list[] = {
+ [DNS_NSSCONF_HOSTS] = "hosts",
+ [DNS_NSSCONF_SUCCESS] = "success",
+ [DNS_NSSCONF_NOTFOUND] = "notfound",
+ [DNS_NSSCONF_UNAVAIL] = "unavail",
+ [DNS_NSSCONF_TRYAGAIN] = "tryagain",
+ [DNS_NSSCONF_CONTINUE] = "continue",
+ [DNS_NSSCONF_RETURN] = "return",
+ [DNS_NSSCONF_FILES] = "files",
+ [DNS_NSSCONF_DNS] = "dns",
+ [DNS_NSSCONF_MDNS] = "mdns",
+ };
+ unsigned i;
+
+ for (i = 1; i < lengthof(list); i++) {
+ if (list[i] && 0 == strcasecmp(list[i], word))
+ return i;
+ }
+
+ return DNS_NSSCONF_INVALID;
+} /* dns_nssconf_keyword() */
+
+
+static enum dns_nssconf_keyword dns_nssconf_c2k(int ch) {
+ static const char map[] = {
+ ['S'] = DNS_NSSCONF_SUCCESS,
+ ['N'] = DNS_NSSCONF_NOTFOUND,
+ ['U'] = DNS_NSSCONF_UNAVAIL,
+ ['T'] = DNS_NSSCONF_TRYAGAIN,
+ ['C'] = DNS_NSSCONF_CONTINUE,
+ ['R'] = DNS_NSSCONF_RETURN,
+ ['f'] = DNS_NSSCONF_FILES,
+ ['F'] = DNS_NSSCONF_FILES,
+ ['d'] = DNS_NSSCONF_DNS,
+ ['D'] = DNS_NSSCONF_DNS,
+ ['b'] = DNS_NSSCONF_DNS,
+ ['B'] = DNS_NSSCONF_DNS,
+ ['m'] = DNS_NSSCONF_MDNS,
+ ['M'] = DNS_NSSCONF_MDNS,
+ };
+
+ return (ch >= 0 && ch < (int)lengthof(map))? map[ch] : DNS_NSSCONF_INVALID;
+} /* dns_nssconf_c2k() */
+
+
+DNS_PRAGMA_PUSH
+DNS_PRAGMA_QUIET
+
+static int dns_nssconf_k2c(int k) {
+ static const char map[DNS_NSSCONF_LAST] = {
+ [DNS_NSSCONF_SUCCESS] = 'S',
+ [DNS_NSSCONF_NOTFOUND] = 'N',
+ [DNS_NSSCONF_UNAVAIL] = 'U',
+ [DNS_NSSCONF_TRYAGAIN] = 'T',
+ [DNS_NSSCONF_CONTINUE] = 'C',
+ [DNS_NSSCONF_RETURN] = 'R',
+ [DNS_NSSCONF_FILES] = 'f',
+ [DNS_NSSCONF_DNS] = 'b',
+ [DNS_NSSCONF_MDNS] = 'm',
+ };
+
+ return (k >= 0 && k < (int)lengthof(map))? (map[k]? map[k] : '?') : '?';
+} /* dns_nssconf_k2c() */
+
+static const char *dns_nssconf_k2s(int k) {
+ static const char *const map[DNS_NSSCONF_LAST] = {
+ [DNS_NSSCONF_SUCCESS] = "SUCCESS",
+ [DNS_NSSCONF_NOTFOUND] = "NOTFOUND",
+ [DNS_NSSCONF_UNAVAIL] = "UNAVAIL",
+ [DNS_NSSCONF_TRYAGAIN] = "TRYAGAIN",
+ [DNS_NSSCONF_CONTINUE] = "continue",
+ [DNS_NSSCONF_RETURN] = "return",
+ [DNS_NSSCONF_FILES] = "files",
+ [DNS_NSSCONF_DNS] = "dns",
+ [DNS_NSSCONF_MDNS] = "mdns",
+ };
+
+ return (k >= 0 && k < (int)lengthof(map))? (map[k]? map[k] : "") : "";
+} /* dns_nssconf_k2s() */
+
+DNS_PRAGMA_POP
+
+
+int dns_nssconf_loadfile(struct dns_resolv_conf *resconf, FILE *fp) {
+ enum dns_nssconf_keyword source, status, action;
+ char lookup[sizeof resconf->lookup] = "", *lp;
+ struct dns_anyconf cf;
+ size_t i;
+ int error;
+
+ while (!feof(fp) && !ferror(fp)) {
+ dns_anyconf_reset(&cf);
+
+ dns_anyconf_skip("%s", fp);
+
+ if (!dns_anyconf_scan(&cf, "%w_", fp, &error))
+ goto nextent;
+
+ if (DNS_NSSCONF_HOSTS != dns_nssconf_keyword(cf.token[0]))
+ goto nextent;
+
+ dns_anyconf_pop(&cf);
+
+ if (!dns_anyconf_skip(": \t", fp))
+ goto nextent;
+
+ *(lp = lookup) = '\0';
+
+ while (dns_anyconf_scan(&cf, "%w_", fp, &error)) {
+ dns_anyconf_skip(" \t", fp);
+
+ if ('[' == dns_anyconf_peek(fp)) {
+ dns_anyconf_skip("[ \t", fp);
+
+ while (dns_anyconf_scan(&cf, "%w_", fp, &error)) {
+ dns_anyconf_skip("= \t", fp);
+ if (!dns_anyconf_scan(&cf, "%w_", fp, &error)) {
+ dns_anyconf_pop(&cf); /* discard status */
+ dns_anyconf_skip("^#;]\n", fp); /* skip to end of criteria */
+ break;
+ }
+ dns_anyconf_skip(" \t", fp);
+ }
+
+ dns_anyconf_skip("] \t", fp);
+ }
+
+ if ((size_t)(endof(lookup) - lp) < cf.count + 1) /* +1 for '\0' */
+ goto nextsrc;
+
+ source = dns_nssconf_keyword(cf.token[0]);
+
+ switch (source) {
+ case DNS_NSSCONF_DNS:
+ case DNS_NSSCONF_MDNS:
+ case DNS_NSSCONF_FILES:
+ *lp++ = dns_nssconf_k2c(source);
+ break;
+ default:
+ goto nextsrc;
+ }
+
+ for (i = 1; i + 1 < cf.count; i += 2) {
+ status = dns_nssconf_keyword(cf.token[i]);
+ action = dns_nssconf_keyword(cf.token[i + 1]);
+
+ switch (status) {
+ case DNS_NSSCONF_SUCCESS:
+ case DNS_NSSCONF_NOTFOUND:
+ case DNS_NSSCONF_UNAVAIL:
+ case DNS_NSSCONF_TRYAGAIN:
+ *lp++ = dns_nssconf_k2c(status);
+ break;
+ default:
+ continue;
+ }
+
+ switch (action) {
+ case DNS_NSSCONF_CONTINUE:
+ case DNS_NSSCONF_RETURN:
+ break;
+ default:
+ action = (status == DNS_NSSCONF_SUCCESS)
+ ? DNS_NSSCONF_RETURN
+ : DNS_NSSCONF_CONTINUE;
+ break;
+ }
+
+ *lp++ = dns_nssconf_k2c(action);
+ }
+nextsrc:
+ *lp = '\0';
+ dns_anyconf_reset(&cf);
+ }
+nextent:
+ dns_anyconf_skip("^\n", fp);
+ }
+
+ if (*lookup)
+ strncpy(resconf->lookup, lookup, sizeof resconf->lookup);
+
+ return 0;
+} /* dns_nssconf_loadfile() */
+
+
+int dns_nssconf_loadpath(struct dns_resolv_conf *resconf, const char *path) {
+ FILE *fp;
+ int error;
+
+ if (!(fp = dns_fopen(path, "rt", &error)))
+ return error;
+
+ error = dns_nssconf_loadfile(resconf, fp);
+
+ fclose(fp);
+
+ return error;
+} /* dns_nssconf_loadpath() */
+
+
+struct dns_nssconf_source {
+ enum dns_nssconf_keyword source, success, notfound, unavail, tryagain;
+}; /* struct dns_nssconf_source */
+
+typedef unsigned dns_nssconf_i;
+
+static inline int dns_nssconf_peek(const struct dns_resolv_conf *resconf, dns_nssconf_i state) {
+ return (state < lengthof(resconf->lookup) && resconf->lookup[state])? resconf->lookup[state] : 0;
+} /* dns_nssconf_peek() */
+
+static _Bool dns_nssconf_next(struct dns_nssconf_source *src, const struct dns_resolv_conf *resconf, dns_nssconf_i *state) {
+ int source, status, action;
+
+ src->source = DNS_NSSCONF_INVALID;
+ src->success = DNS_NSSCONF_RETURN;
+ src->notfound = DNS_NSSCONF_CONTINUE;
+ src->unavail = DNS_NSSCONF_CONTINUE;
+ src->tryagain = DNS_NSSCONF_CONTINUE;
+
+ while ((source = dns_nssconf_peek(resconf, *state))) {
+ source = dns_nssconf_c2k(source);
+ ++*state;
+
+ switch (source) {
+ case DNS_NSSCONF_FILES:
+ case DNS_NSSCONF_DNS:
+ case DNS_NSSCONF_MDNS:
+ src->source = source;
+ break;
+ default:
+ continue;
+ }
+
+ while ((status = dns_nssconf_peek(resconf, *state)) && (action = dns_nssconf_peek(resconf, *state + 1))) {
+ status = dns_nssconf_c2k(status);
+ action = dns_nssconf_c2k(action);
+
+ switch (action) {
+ case DNS_NSSCONF_RETURN:
+ case DNS_NSSCONF_CONTINUE:
+ break;
+ default:
+ goto done;
+ }
+
+ switch (status) {
+ case DNS_NSSCONF_SUCCESS:
+ src->success = action;
+ break;
+ case DNS_NSSCONF_NOTFOUND:
+ src->notfound = action;
+ break;
+ case DNS_NSSCONF_UNAVAIL:
+ src->unavail = action;
+ break;
+ case DNS_NSSCONF_TRYAGAIN:
+ src->tryagain = action;
+ break;
+ default:
+ goto done;
+ }
+
+ *state += 2;
+ }
+
+ break;
+ }
+done:
+ return src->source != DNS_NSSCONF_INVALID;
+} /* dns_nssconf_next() */
+
+
+static int dns_nssconf_dump_status(int status, int action, unsigned *count, FILE *fp) {
+ switch (status) {
+ case DNS_NSSCONF_SUCCESS:
+ if (action == DNS_NSSCONF_RETURN)
+ return 0;
+ break;
+ default:
+ if (action == DNS_NSSCONF_CONTINUE)
+ return 0;
+ break;
+ }
+
+ fputc(' ', fp);
+
+ if (!*count)
+ fputc('[', fp);
+
+ fprintf(fp, "%s=%s", dns_nssconf_k2s(status), dns_nssconf_k2s(action));
+
+ ++*count;
+
+ return 0;
+} /* dns_nssconf_dump_status() */
+
+
+int dns_nssconf_dump(struct dns_resolv_conf *resconf, FILE *fp) {
+ struct dns_nssconf_source src;
+ dns_nssconf_i i = 0;
+
+ fputs("hosts:", fp);
+
+ while (dns_nssconf_next(&src, resconf, &i)) {
+ unsigned n = 0;
+
+ fprintf(fp, " %s", dns_nssconf_k2s(src.source));
+
+ dns_nssconf_dump_status(DNS_NSSCONF_SUCCESS, src.success, &n, fp);
+ dns_nssconf_dump_status(DNS_NSSCONF_NOTFOUND, src.notfound, &n, fp);
+ dns_nssconf_dump_status(DNS_NSSCONF_UNAVAIL, src.unavail, &n, fp);
+ dns_nssconf_dump_status(DNS_NSSCONF_TRYAGAIN, src.tryagain, &n, fp);
+
+ if (n)
+ fputc(']', fp);
+ }
+
+ fputc('\n', fp);
+
+ return 0;
+} /* dns_nssconf_dump() */
+
+
+int dns_resconf_setiface(struct dns_resolv_conf *resconf, const char *addr, unsigned short port) {
+ int af = (strchr(addr, ':'))? AF_INET6 : AF_INET;
+ int error;
+
+ if ((error = dns_pton(af, addr, dns_sa_addr(af, &resconf->iface, NULL))))
+ return error;
+
+ *dns_sa_port(af, &resconf->iface) = htons(port);
+ resconf->iface.ss_family = af;
+
+ return 0;
+} /* dns_resconf_setiface() */
+
+
+#define DNS_SM_RESTORE \
+ do { \
+ pc = 0xff & (*state >> 0); \
+ srchi = 0xff & (*state >> 8); \
+ ndots = 0xff & (*state >> 16); \
+ } while (0)
+
+#define DNS_SM_SAVE \
+ do { \
+ *state = ((0xff & pc) << 0) \
+ | ((0xff & srchi) << 8) \
+ | ((0xff & ndots) << 16); \
+ } while (0)
+
+size_t dns_resconf_search(void *dst, size_t lim, const void *qname, size_t qlen, struct dns_resolv_conf *resconf, dns_resconf_i_t *state) {
+ unsigned pc, srchi, ndots, len;
+
+ DNS_SM_ENTER;
+
+ /* if FQDN then return as-is and finish */
+ if (dns_d_isanchored(qname, qlen)) {
+ len = dns_d_anchor(dst, lim, qname, qlen);
+ DNS_SM_YIELD(len);
+ DNS_SM_EXIT;
+ }
+
+ ndots = dns_d_ndots(qname, qlen);
+
+ if (ndots >= resconf->options.ndots) {
+ len = dns_d_anchor(dst, lim, qname, qlen);
+ DNS_SM_YIELD(len);
+ }
+
+ while (srchi < lengthof(resconf->search) && resconf->search[srchi][0]) {
+ struct dns_buf buf = DNS_B_INTO(dst, lim);
+ const char *dn = resconf->search[srchi++];
+
+ dns_b_put(&buf, qname, qlen);
+ dns_b_putc(&buf, '.');
+ dns_b_puts(&buf, dn);
+ if (!dns_d_isanchored(dn, strlen(dn)))
+ dns_b_putc(&buf, '.');
+ len = dns_b_strllen(&buf);
+ DNS_SM_YIELD(len);
+ }
+
+ if (ndots < resconf->options.ndots) {
+ len = dns_d_anchor(dst, lim, qname, qlen);
+ DNS_SM_YIELD(len);
+ }
+
+ DNS_SM_LEAVE;
+
+ return dns_strlcpy(dst, "", lim);
+} /* dns_resconf_search() */
+
+#undef DNS_SM_SAVE
+#undef DNS_SM_RESTORE
+
+
+int dns_resconf_dump(struct dns_resolv_conf *resconf, FILE *fp) {
+ unsigned i;
+ int af;
+
+ for (i = 0; i < lengthof(resconf->nameserver) && (af = resconf->nameserver[i].ss_family) != AF_UNSPEC; i++) {
+ char addr[INET6_ADDRSTRLEN + 1] = "[INVALID]";
+ unsigned short port;
+
+ dns_inet_ntop(af, dns_sa_addr(af, &resconf->nameserver[i], NULL), addr, sizeof addr);
+ port = ntohs(*dns_sa_port(af, &resconf->nameserver[i]));
+
+ if (port == 53)
+ fprintf(fp, "nameserver %s\n", addr);
+ else
+ fprintf(fp, "nameserver [%s]:%hu\n", addr, port);
+ }
+
+
+ fprintf(fp, "search");
+
+ for (i = 0; i < lengthof(resconf->search) && resconf->search[i][0]; i++)
+ fprintf(fp, " %s", resconf->search[i]);
+
+ fputc('\n', fp);
+
+
+ fputs("; ", fp);
+ dns_nssconf_dump(resconf, fp);
+
+ fprintf(fp, "lookup");
+
+ for (i = 0; i < lengthof(resconf->lookup) && resconf->lookup[i]; i++) {
+ switch (resconf->lookup[i]) {
+ case 'b':
+ fprintf(fp, " bind"); break;
+ case 'f':
+ fprintf(fp, " file"); break;
+ case 'c':
+ fprintf(fp, " cache"); break;
+ }
+ }
+
+ fputc('\n', fp);
+
+
+ fprintf(fp, "options ndots:%u timeout:%u attempts:%u", resconf->options.ndots, resconf->options.timeout, resconf->options.attempts);
+
+ if (resconf->options.edns0)
+ fprintf(fp, " edns0");
+ if (resconf->options.rotate)
+ fprintf(fp, " rotate");
+ if (resconf->options.recurse)
+ fprintf(fp, " recurse");
+ if (resconf->options.smart)
+ fprintf(fp, " smart");
+
+ switch (resconf->options.tcp) {
+ case DNS_RESCONF_TCP_ENABLE:
+ break;
+ case DNS_RESCONF_TCP_ONLY:
+ fprintf(fp, " tcp");
+ break;
+ case DNS_RESCONF_TCP_SOCKS:
+ fprintf(fp, " tcp:socks");
+ break;
+ case DNS_RESCONF_TCP_DISABLE:
+ fprintf(fp, " tcp:disable");
+ break;
+ }
+
+ fputc('\n', fp);
+
+
+ if ((af = resconf->iface.ss_family) != AF_UNSPEC) {
+ char addr[INET6_ADDRSTRLEN + 1] = "[INVALID]";
+
+ dns_inet_ntop(af, dns_sa_addr(af, &resconf->iface, NULL), addr, sizeof addr);
+
+ fprintf(fp, "interface %s %hu\n", addr, ntohs(*dns_sa_port(af, &resconf->iface)));
+ }
+
+ return 0;
+} /* dns_resconf_dump() */
+
+
+/*
+ * H I N T S E R V E R R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_hints_soa {
+ unsigned char zone[DNS_D_MAXNAME + 1];
+
+ struct {
+ struct sockaddr_storage ss;
+ unsigned priority;
+ } addrs[16];
+
+ unsigned count;
+
+ struct dns_hints_soa *next;
+}; /* struct dns_hints_soa */
+
+
+struct dns_hints {
+ dns_atomic_t refcount;
+
+ struct dns_hints_soa *head;
+}; /* struct dns_hints */
+
+
+struct dns_hints *dns_hints_open(struct dns_resolv_conf *resconf, int *error) {
+ static const struct dns_hints H_initializer;
+ struct dns_hints *H;
+
+ (void)resconf;
+
+ if (!(H = malloc(sizeof *H)))
+ goto syerr;
+
+ *H = H_initializer;
+
+ dns_hints_acquire(H);
+
+ return H;
+syerr:
+ *error = dns_syerr();
+
+ free(H);
+
+ return 0;
+} /* dns_hints_open() */
+
+
+void dns_hints_close(struct dns_hints *H) {
+ struct dns_hints_soa *soa, *nxt;
+
+ if (!H || 1 != dns_hints_release(H))
+ return /* void */;
+
+ for (soa = H->head; soa; soa = nxt) {
+ nxt = soa->next;
+
+ free(soa);
+ }
+
+ free(H);
+
+ return /* void */;
+} /* dns_hints_close() */
+
+
+dns_refcount_t dns_hints_acquire(struct dns_hints *H) {
+ return dns_atomic_fetch_add(&H->refcount);
+} /* dns_hints_acquire() */
+
+
+dns_refcount_t dns_hints_release(struct dns_hints *H) {
+ return dns_atomic_fetch_sub(&H->refcount);
+} /* dns_hints_release() */
+
+
+struct dns_hints *dns_hints_mortal(struct dns_hints *hints) {
+ if (hints)
+ dns_hints_release(hints);
+
+ return hints;
+} /* dns_hints_mortal() */
+
+
+struct dns_hints *dns_hints_local(struct dns_resolv_conf *resconf, int *error_) {
+ struct dns_hints *hints = 0;
+ int error;
+
+ if (resconf)
+ dns_resconf_acquire(resconf);
+ else if (!(resconf = dns_resconf_local(&error)))
+ goto error;
+
+ if (!(hints = dns_hints_open(resconf, &error)))
+ goto error;
+
+ error = 0;
+
+ if (0 == dns_hints_insert_resconf(hints, ".", resconf, &error) && error)
+ goto error;
+
+ dns_resconf_close(resconf);
+
+ return hints;
+error:
+ *error_ = error;
+
+ dns_resconf_close(resconf);
+ dns_hints_close(hints);
+
+ return 0;
+} /* dns_hints_local() */
+
+
+struct dns_hints *dns_hints_root(struct dns_resolv_conf *resconf, int *error_) {
+ static const struct {
+ int af;
+ char addr[INET6_ADDRSTRLEN];
+ } root_hints[] = {
+ { AF_INET, "198.41.0.4" }, /* A.ROOT-SERVERS.NET. */
+ { AF_INET6, "2001:503:ba3e::2:30" }, /* A.ROOT-SERVERS.NET. */
+ { AF_INET, "192.228.79.201" }, /* B.ROOT-SERVERS.NET. */
+ { AF_INET6, "2001:500:84::b" }, /* B.ROOT-SERVERS.NET. */
+ { AF_INET, "192.33.4.12" }, /* C.ROOT-SERVERS.NET. */
+ { AF_INET6, "2001:500:2::c" }, /* C.ROOT-SERVERS.NET. */
+ { AF_INET, "199.7.91.13" }, /* D.ROOT-SERVERS.NET. */
+ { AF_INET6, "2001:500:2d::d" }, /* D.ROOT-SERVERS.NET. */
+ { AF_INET, "192.203.230.10" }, /* E.ROOT-SERVERS.NET. */
+ { AF_INET, "192.5.5.241" }, /* F.ROOT-SERVERS.NET. */
+ { AF_INET6, "2001:500:2f::f" }, /* F.ROOT-SERVERS.NET. */
+ { AF_INET, "192.112.36.4" }, /* G.ROOT-SERVERS.NET. */
+ { AF_INET, "128.63.2.53" }, /* H.ROOT-SERVERS.NET. */
+ { AF_INET6, "2001:500:1::803f:235" }, /* H.ROOT-SERVERS.NET. */
+ { AF_INET, "192.36.148.17" }, /* I.ROOT-SERVERS.NET. */
+ { AF_INET6, "2001:7FE::53" }, /* I.ROOT-SERVERS.NET. */
+ { AF_INET, "192.58.128.30" }, /* J.ROOT-SERVERS.NET. */
+ { AF_INET6, "2001:503:c27::2:30" }, /* J.ROOT-SERVERS.NET. */
+ { AF_INET, "193.0.14.129" }, /* K.ROOT-SERVERS.NET. */
+ { AF_INET6, "2001:7FD::1" }, /* K.ROOT-SERVERS.NET. */
+ { AF_INET, "199.7.83.42" }, /* L.ROOT-SERVERS.NET. */
+ { AF_INET6, "2001:500:3::42" }, /* L.ROOT-SERVERS.NET. */
+ { AF_INET, "202.12.27.33" }, /* M.ROOT-SERVERS.NET. */
+ { AF_INET6, "2001:DC3::35" }, /* M.ROOT-SERVERS.NET. */
+ };
+ struct dns_hints *hints = 0;
+ struct sockaddr_storage ss;
+ unsigned i;
+ int error, af;
+
+ if (!(hints = dns_hints_open(resconf, &error)))
+ goto error;
+
+ for (i = 0; i < lengthof(root_hints); i++) {
+ af = root_hints[i].af;
+
+ if ((error = dns_pton(af, root_hints[i].addr, dns_sa_addr(af, &ss, NULL))))
+ goto error;
+
+ *dns_sa_port(af, &ss) = htons(53);
+ ss.ss_family = af;
+
+ if ((error = dns_hints_insert(hints, ".", (struct sockaddr *)&ss, 1)))
+ goto error;
+ }
+
+ return hints;
+error:
+ *error_ = error;
+
+ dns_hints_close(hints);
+
+ return 0;
+} /* dns_hints_root() */
+
+
+static struct dns_hints_soa *dns_hints_fetch(struct dns_hints *H, const char *zone) {
+ struct dns_hints_soa *soa;
+
+ for (soa = H->head; soa; soa = soa->next) {
+ if (0 == strcasecmp(zone, (char *)soa->zone))
+ return soa;
+ }
+
+ return 0;
+} /* dns_hints_fetch() */
+
+
+int dns_hints_insert(struct dns_hints *H, const char *zone, const struct sockaddr *sa, unsigned priority) {
+ static const struct dns_hints_soa soa_initializer;
+ struct dns_hints_soa *soa;
+ unsigned i;
+
+ if (!(soa = dns_hints_fetch(H, zone))) {
+ if (!(soa = malloc(sizeof *soa)))
+ return dns_syerr();
+ *soa = soa_initializer;
+ dns_strlcpy((char *)soa->zone, zone, sizeof soa->zone);
+
+ soa->next = H->head;
+ H->head = soa;
+ }
+
+ i = soa->count % lengthof(soa->addrs);
+
+ memcpy(&soa->addrs[i].ss, sa, dns_sa_len(sa));
+
+ soa->addrs[i].priority = DNS_PP_MAX(1, priority);
+
+ if (soa->count < lengthof(soa->addrs))
+ soa->count++;
+
+ return 0;
+} /* dns_hints_insert() */
+
+
+static _Bool dns_hints_isinaddr_any(const void *sa) {
+ struct in_addr *addr;
+
+ if (dns_sa_family(sa) != AF_INET)
+ return 0;
+
+ addr = dns_sa_addr(AF_INET, sa, NULL);
+ return addr->s_addr == htonl(INADDR_ANY);
+}
+
+unsigned dns_hints_insert_resconf(struct dns_hints *H, const char *zone, const struct dns_resolv_conf *resconf, int *error_) {
+ unsigned i, n, p;
+ int error;
+
+ for (i = 0, n = 0, p = 1; i < lengthof(resconf->nameserver) && resconf->nameserver[i].ss_family != AF_UNSPEC; i++, n++) {
+ union { struct sockaddr_in sin; } tmp;
+ struct sockaddr *ns;
+
+ /*
+ * dns_resconf_open initializes nameserver[0] to INADDR_ANY.
+ *
+ * Traditionally the semantics of 0.0.0.0 meant the default
+ * interface, which evolved to mean the loopback interface.
+ * See comment block preceding resolv/res_init.c:res_init in
+ * glibc 2.23. As of 2.23, glibc no longer translates
+ * 0.0.0.0 despite the code comment, but it does default to
+ * 127.0.0.1 when no nameservers are present.
+ *
+ * BIND9 as of 9.10.3 still translates 0.0.0.0 to 127.0.0.1.
+ * See lib/lwres/lwconfig.c:lwres_create_addr and the
+ * convert_zero flag. 127.0.0.1 is also the default when no
+ * nameservers are present.
+ */
+ if (dns_hints_isinaddr_any(&resconf->nameserver[i])) {
+ memcpy(&tmp.sin, &resconf->nameserver[i], sizeof tmp.sin);
+ tmp.sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+ ns = (struct sockaddr *)&tmp.sin;
+ } else {
+ ns = (struct sockaddr *)&resconf->nameserver[i];
+ }
+
+ if ((error = dns_hints_insert(H, zone, ns, p)))
+ goto error;
+
+ p += !resconf->options.rotate;
+ }
+
+ return n;
+error:
+ *error_ = error;
+
+ return n;
+} /* dns_hints_insert_resconf() */
+
+
+static int dns_hints_i_cmp(unsigned a, unsigned b, struct dns_hints_i *i, struct dns_hints_soa *soa) {
+ int cmp;
+
+ if ((cmp = soa->addrs[a].priority - soa->addrs[b].priority))
+ return cmp;
+
+ return dns_k_shuffle16(a, i->state.seed) - dns_k_shuffle16(b, i->state.seed);
+} /* dns_hints_i_cmp() */
+
+
+static unsigned dns_hints_i_start(struct dns_hints_i *i, struct dns_hints_soa *soa) {
+ unsigned p0, p;
+
+ p0 = 0;
+
+ for (p = 1; p < soa->count; p++) {
+ if (dns_hints_i_cmp(p, p0, i, soa) < 0)
+ p0 = p;
+ }
+
+ return p0;
+} /* dns_hints_i_start() */
+
+
+static unsigned dns_hints_i_skip(unsigned p0, struct dns_hints_i *i, struct dns_hints_soa *soa) {
+ unsigned pZ, p;
+
+ for (pZ = 0; pZ < soa->count; pZ++) {
+ if (dns_hints_i_cmp(pZ, p0, i, soa) > 0)
+ goto cont;
+ }
+
+ return soa->count;
+cont:
+ for (p = pZ + 1; p < soa->count; p++) {
+ if (dns_hints_i_cmp(p, p0, i, soa) <= 0)
+ continue;
+
+ if (dns_hints_i_cmp(p, pZ, i, soa) >= 0)
+ continue;
+
+ pZ = p;
+ }
+
+
+ return pZ;
+} /* dns_hints_i_skip() */
+
+
+static struct dns_hints_i *dns_hints_i_init(struct dns_hints_i *i, struct dns_hints *hints) {
+ static const struct dns_hints_i i_initializer;
+ struct dns_hints_soa *soa;
+
+ i->state = i_initializer.state;
+
+ do {
+ i->state.seed = dns_random();
+ } while (0 == i->state.seed);
+
+ if ((soa = dns_hints_fetch(hints, i->zone))) {
+ i->state.next = dns_hints_i_start(i, soa);
+ }
+
+ return i;
+} /* dns_hints_i_init() */
+
+
+unsigned dns_hints_grep(struct sockaddr **sa, socklen_t *sa_len, unsigned lim, struct dns_hints_i *i, struct dns_hints *H) {
+ struct dns_hints_soa *soa;
+ unsigned n;
+
+ if (!(soa = dns_hints_fetch(H, i->zone)))
+ return 0;
+
+ n = 0;
+
+ while (i->state.next < soa->count && n < lim) {
+ *sa = (struct sockaddr *)&soa->addrs[i->state.next].ss;
+ *sa_len = dns_sa_len(*sa);
+
+ sa++;
+ sa_len++;
+ n++;
+
+ i->state.next = dns_hints_i_skip(i->state.next, i, soa);
+ }
+
+ return n;
+} /* dns_hints_grep() */
+
+
+struct dns_packet *dns_hints_query(struct dns_hints *hints, struct dns_packet *Q, int *error_) {
+ struct dns_packet *A, *P;
+ struct dns_rr rr;
+ char zone[DNS_D_MAXNAME + 1];
+ size_t zlen;
+ struct dns_hints_i i;
+ struct sockaddr *sa;
+ socklen_t slen;
+ int error;
+
+ if (!dns_rr_grep(&rr, 1, dns_rr_i_new(Q, .section = DNS_S_QUESTION), Q, &error))
+ goto error;
+
+ if (!(zlen = dns_d_expand(zone, sizeof zone, rr.dn.p, Q, &error)))
+ goto error;
+ else if (zlen >= sizeof zone)
+ goto toolong;
+
+ P = dns_p_new(512);
+ dns_header(P)->qr = 1;
+
+ if ((error = dns_rr_copy(P, &rr, Q)))
+ goto error;
+
+ if ((error = dns_p_push(P, DNS_S_AUTHORITY, ".", strlen("."), DNS_T_NS, DNS_C_IN, 0, "hints.local.")))
+ goto error;
+
+ do {
+ i.zone = zone;
+
+ dns_hints_i_init(&i, hints);
+
+ while (dns_hints_grep(&sa, &slen, 1, &i, hints)) {
+ int af = sa->sa_family;
+ int rtype = (af == AF_INET6)? DNS_T_AAAA : DNS_T_A;
+
+ if ((error = dns_p_push(P, DNS_S_ADDITIONAL, "hints.local.", strlen("hints.local."), rtype, DNS_C_IN, 0, dns_sa_addr(af, sa, NULL))))
+ goto error;
+ }
+ } while ((zlen = dns_d_cleave(zone, sizeof zone, zone, zlen)));
+
+ if (!(A = dns_p_copy(dns_p_make(P->end, &error), P)))
+ goto error;
+
+ return A;
+toolong:
+ error = DNS_EILLEGAL;
+error:
+ *error_ = error;
+
+ return 0;
+} /* dns_hints_query() */
+
+
+/** ugly hack to support specifying ports other than 53 in resolv.conf. */
+static unsigned short dns_hints_port(struct dns_hints *hints, int af, void *addr) {
+ struct dns_hints_soa *soa;
+ void *addrsoa;
+ socklen_t addrlen;
+ unsigned short port;
+ unsigned i;
+
+ for (soa = hints->head; soa; soa = soa->next) {
+ for (i = 0; i < soa->count; i++) {
+ if (af != soa->addrs[i].ss.ss_family)
+ continue;
+
+ if (!(addrsoa = dns_sa_addr(af, &soa->addrs[i].ss, &addrlen)))
+ continue;
+
+ if (memcmp(addr, addrsoa, addrlen))
+ continue;
+
+ port = *dns_sa_port(af, &soa->addrs[i].ss);
+
+ return (port)? port : htons(53);
+ }
+ }
+
+ return htons(53);
+} /* dns_hints_port() */
+
+
+int dns_hints_dump(struct dns_hints *hints, FILE *fp) {
+ struct dns_hints_soa *soa;
+ char addr[INET6_ADDRSTRLEN];
+ unsigned i;
+ int af, error;
+
+ for (soa = hints->head; soa; soa = soa->next) {
+ fprintf(fp, "ZONE \"%s\"\n", soa->zone);
+
+ for (i = 0; i < soa->count; i++) {
+ af = soa->addrs[i].ss.ss_family;
+
+ if ((error = dns_ntop(af, dns_sa_addr(af, &soa->addrs[i].ss, NULL), addr, sizeof addr)))
+ return error;
+
+ fprintf(fp, "\t(%d) [%s]:%hu\n", (int)soa->addrs[i].priority, addr, ntohs(*dns_sa_port(af, &soa->addrs[i].ss)));
+ }
+ }
+
+ return 0;
+} /* dns_hints_dump() */
+
+
+/*
+ * C A C H E R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+static dns_refcount_t dns_cache_acquire(struct dns_cache *cache) {
+ return dns_atomic_fetch_add(&cache->_.refcount);
+} /* dns_cache_acquire() */
+
+
+static dns_refcount_t dns_cache_release(struct dns_cache *cache) {
+ return dns_atomic_fetch_sub(&cache->_.refcount);
+} /* dns_cache_release() */
+
+
+static struct dns_packet *dns_cache_query(struct dns_packet *query, struct dns_cache *cache, int *error) {
+ (void)query;
+ (void)cache;
+ (void)error;
+
+ return NULL;
+} /* dns_cache_query() */
+
+
+static int dns_cache_submit(struct dns_packet *query, struct dns_cache *cache) {
+ (void)query;
+ (void)cache;
+
+ return 0;
+} /* dns_cache_submit() */
+
+
+static int dns_cache_check(struct dns_cache *cache) {
+ (void)cache;
+
+ return 0;
+} /* dns_cache_check() */
+
+
+static struct dns_packet *dns_cache_fetch(struct dns_cache *cache, int *error) {
+ (void)cache;
+ (void)error;
+
+ return NULL;
+} /* dns_cache_fetch() */
+
+
+static int dns_cache_pollfd(struct dns_cache *cache) {
+ (void)cache;
+
+ return -1;
+} /* dns_cache_pollfd() */
+
+
+static short dns_cache_events(struct dns_cache *cache) {
+ (void)cache;
+
+ return 0;
+} /* dns_cache_events() */
+
+
+static void dns_cache_clear(struct dns_cache *cache) {
+ (void)cache;
+
+ return;
+} /* dns_cache_clear() */
+
+
+struct dns_cache *dns_cache_init(struct dns_cache *cache) {
+ static const struct dns_cache c_init = {
+ .acquire = &dns_cache_acquire,
+ .release = &dns_cache_release,
+ .query = &dns_cache_query,
+ .submit = &dns_cache_submit,
+ .check = &dns_cache_check,
+ .fetch = &dns_cache_fetch,
+ .pollfd = &dns_cache_pollfd,
+ .events = &dns_cache_events,
+ .clear = &dns_cache_clear,
+ ._ = { .refcount = 1, },
+ };
+
+ *cache = c_init;
+
+ return cache;
+} /* dns_cache_init() */
+
+
+void dns_cache_close(struct dns_cache *cache) {
+ if (cache)
+ cache->release(cache);
+} /* dns_cache_close() */
+
+
+/*
+ * S O C K E T R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+static void dns_socketclose(int *fd, const struct dns_options *opts) {
+ if (opts && opts->closefd.cb)
+ opts->closefd.cb(fd, opts->closefd.arg);
+
+ if (*fd != -1) {
+#if _WIN32
+ closesocket(*fd);
+#else
+ close(*fd);
+#endif
+ *fd = -1;
+ }
+} /* dns_socketclose() */
+
+
+#ifndef HAVE_IOCTLSOCKET
+#define HAVE_IOCTLSOCKET (_WIN32 || _WIN64)
+#endif
+
+#ifndef HAVE_SOCK_CLOEXEC
+#define HAVE_SOCK_CLOEXEC (defined SOCK_CLOEXEC)
+#endif
+
+#ifndef HAVE_SOCK_NONBLOCK
+#define HAVE_SOCK_NONBLOCK (defined SOCK_NONBLOCK)
+#endif
+
+#define DNS_SO_MAXTRY 7
+
+static int dns_socket(struct sockaddr *local, int type, int *error_) {
+ int fd = -1, flags, error;
+#if defined FIONBIO
+ unsigned long opt;
+#endif
+
+ flags = 0;
+#if HAVE_SOCK_CLOEXEC
+ flags |= SOCK_CLOEXEC;
+#endif
+#if HAVE_SOCK_NONBLOCK
+ flags |= SOCK_NONBLOCK;
+#endif
+ if (-1 == (fd = socket(local->sa_family, type|flags, 0)))
+ goto soerr;
+
+#if defined F_SETFD && !HAVE_SOCK_CLOEXEC
+ if (-1 == fcntl(fd, F_SETFD, 1))
+ goto syerr;
+#endif
+
+#if defined O_NONBLOCK && !HAVE_SOCK_NONBLOCK
+ if (-1 == (flags = fcntl(fd, F_GETFL)))
+ goto syerr;
+ if (-1 == fcntl(fd, F_SETFL, flags | O_NONBLOCK))
+ goto syerr;
+#elif defined FIONBIO && HAVE_IOCTLSOCKET
+ opt = 1;
+ if (0 != ioctlsocket(fd, FIONBIO, &opt))
+ goto soerr;
+#endif
+
+#if defined SO_NOSIGPIPE
+ if (type != SOCK_DGRAM) {
+ if (0 != setsockopt(fd, SOL_SOCKET, SO_NOSIGPIPE, &(int){ 1 }, sizeof (int)))
+ goto soerr;
+ }
+#endif
+
+ if (local->sa_family != AF_INET && local->sa_family != AF_INET6)
+ return fd;
+
+ if (type != SOCK_DGRAM)
+ return fd;
+
+ /*
+ * FreeBSD, Linux, OpenBSD, OS X, and Solaris use random ports by
+ * default. Though the ephemeral range is quite small on OS X
+ * (49152-65535 on 10.10) and Linux (32768-60999 on 4.4.0, Ubuntu
+ * Xenial). See also RFC 6056.
+ *
+ * TODO: Optionally rely on the kernel to select a random port.
+ */
+ if (*dns_sa_port(local->sa_family, local) == 0) {
+ struct sockaddr_storage tmp;
+ unsigned i, port;
+
+ memcpy(&tmp, local, dns_sa_len(local));
+
+ for (i = 0; i < DNS_SO_MAXTRY; i++) {
+ port = 1025 + (dns_random() % 64510);
+
+ *dns_sa_port(tmp.ss_family, &tmp) = htons(port);
+
+ if (0 == bind(fd, (struct sockaddr *)&tmp, dns_sa_len(&tmp)))
+ return fd;
+ }
+
+ /* NB: continue to next bind statement */
+ }
+
+ if (0 == bind(fd, local, dns_sa_len(local)))
+ return fd;
+
+ /* FALL THROUGH */
+soerr:
+ error = dns_soerr();
+
+ goto error;
+#if (defined F_SETFD && !HAVE_SOCK_CLOEXEC) || (defined O_NONBLOCK && !HAVE_SOCK_NONBLOCK)
+syerr:
+ error = dns_syerr();
+
+ goto error;
+#endif
+error:
+ *error_ = error;
+
+ dns_socketclose(&fd, NULL);
+
+ return -1;
+} /* dns_socket() */
+
+
+enum {
+ DNS_SO_UDP_INIT = 1,
+ DNS_SO_UDP_CONN,
+ DNS_SO_UDP_SEND,
+ DNS_SO_UDP_RECV,
+ DNS_SO_UDP_DONE,
+
+ DNS_SO_TCP_INIT,
+ DNS_SO_TCP_CONN,
+ DNS_SO_TCP_SEND,
+ DNS_SO_TCP_RECV,
+ DNS_SO_TCP_DONE,
+
+ DNS_SO_SOCKS_INIT,
+ DNS_SO_SOCKS_CONN,
+ DNS_SO_SOCKS_AUTH_SEND,
+ DNS_SO_SOCKS_AUTH_RECV,
+ DNS_SO_SOCKS_REQUEST_SEND,
+ DNS_SO_SOCKS_REQUEST_RECV,
+ DNS_SO_SOCKS_REQUEST_RECV_V6,
+ DNS_SO_SOCKS_HANDSHAKE_DONE,
+};
+
+struct dns_socket {
+ struct dns_options opts;
+
+ int udp;
+ int tcp;
+
+ int *old;
+ unsigned onum, olim;
+
+ int type;
+
+ struct sockaddr_storage local, remote;
+
+ struct dns_k_permutor qids;
+
+ struct dns_stat stat;
+
+ struct dns_trace *trace;
+
+ /*
+ * NOTE: dns_so_reset() zeroes everything from here down.
+ */
+ int state;
+
+ unsigned short qid;
+ char qname[DNS_D_MAXNAME + 1];
+ size_t qlen;
+ enum dns_type qtype;
+ enum dns_class qclass;
+
+ struct dns_packet *query;
+ size_t qout;
+
+ /* During a SOCKS handshake the query is temporarily stored
+ * here. */
+ struct dns_packet *query_backup;
+
+ struct dns_clock elapsed;
+
+ struct dns_packet *answer;
+ size_t alen, apos;
+}; /* struct dns_socket */
+
+
+/*
+ * NOTE: Actual closure delayed so that kqueue(2) and epoll(2) callers have
+ * a chance to recognize a state change after installing a persistent event
+ * and where sequential descriptors with the same integer value returned
+ * from _pollfd() would be ambiguous. See dns_so_closefds().
+ */
+static int dns_so_closefd(struct dns_socket *so, int *fd) {
+ int error;
+
+ if (*fd == -1)
+ return 0;
+
+ if (so->opts.closefd.cb) {
+ if ((error = so->opts.closefd.cb(fd, so->opts.closefd.arg))) {
+ return error;
+ } else if (*fd == -1)
+ return 0;
+ }
+
+ if (!(so->onum < so->olim)) {
+ unsigned olim = DNS_PP_MAX(4, so->olim * 2);
+ void *old;
+
+ if (!(old = realloc(so->old, sizeof so->old[0] * olim)))
+ return dns_syerr();
+
+ so->old = old;
+ so->olim = olim;
+ }
+
+ so->old[so->onum++] = *fd;
+ *fd = -1;
+
+ return 0;
+} /* dns_so_closefd() */
+
+
+#define DNS_SO_CLOSE_UDP 0x01
+#define DNS_SO_CLOSE_TCP 0x02
+#define DNS_SO_CLOSE_OLD 0x04
+#define DNS_SO_CLOSE_ALL (DNS_SO_CLOSE_UDP|DNS_SO_CLOSE_TCP|DNS_SO_CLOSE_OLD)
+
+static void dns_so_closefds(struct dns_socket *so, int which) {
+ if (DNS_SO_CLOSE_UDP & which)
+ dns_socketclose(&so->udp, &so->opts);
+ if (DNS_SO_CLOSE_TCP & which)
+ dns_socketclose(&so->tcp, &so->opts);
+ if (DNS_SO_CLOSE_OLD & which) {
+ unsigned i;
+ for (i = 0; i < so->onum; i++)
+ dns_socketclose(&so->old[i], &so->opts);
+ so->onum = 0;
+ free(so->old);
+ so->old = 0;
+ so->olim = 0;
+ }
+} /* dns_so_closefds() */
+
+
+static void dns_so_destroy(struct dns_socket *);
+
+static struct dns_socket *dns_so_init(struct dns_socket *so, const struct sockaddr *local, int type, const struct dns_options *opts, int *error) {
+ static const struct dns_socket so_initializer = { .opts = DNS_OPTS_INITIALIZER, .udp = -1, .tcp = -1, };
+
+ *so = so_initializer;
+ so->type = type;
+
+ if (opts)
+ so->opts = *opts;
+
+ if (local)
+ memcpy(&so->local, local, dns_sa_len(local));
+
+ if (-1 == (so->udp = dns_socket((struct sockaddr *)&so->local, SOCK_DGRAM, error)))
+ goto error;
+
+ dns_k_permutor_init(&so->qids, 1, 65535);
+
+ return so;
+error:
+ dns_so_destroy(so);
+
+ return 0;
+} /* dns_so_init() */
+
+
+struct dns_socket *dns_so_open(const struct sockaddr *local, int type, const struct dns_options *opts, int *error) {
+ struct dns_socket *so;
+
+ if (!(so = malloc(sizeof *so)))
+ goto syerr;
+
+ if (!dns_so_init(so, local, type, opts, error))
+ goto error;
+
+ return so;
+syerr:
+ *error = dns_syerr();
+error:
+ dns_so_close(so);
+
+ return 0;
+} /* dns_so_open() */
+
+
+static void dns_so_destroy(struct dns_socket *so) {
+ dns_so_reset(so);
+ dns_so_closefds(so, DNS_SO_CLOSE_ALL);
+ dns_trace_close(so->trace);
+} /* dns_so_destroy() */
+
+
+void dns_so_close(struct dns_socket *so) {
+ if (!so)
+ return;
+
+ dns_so_destroy(so);
+
+ free(so);
+} /* dns_so_close() */
+
+
+void dns_so_reset(struct dns_socket *so) {
+ dns_p_setptr(&so->answer, NULL);
+
+ memset(&so->state, '\0', sizeof *so - offsetof(struct dns_socket, state));
+} /* dns_so_reset() */
+
+
+unsigned short dns_so_mkqid(struct dns_socket *so) {
+ return dns_k_permutor_step(&so->qids);
+} /* dns_so_mkqid() */
+
+
+#define DNS_SO_MINBUF 768
+
+static int dns_so_newanswer(struct dns_socket *so, size_t len) {
+ size_t size = offsetof(struct dns_packet, data) + DNS_PP_MAX(len, DNS_SO_MINBUF);
+ void *p;
+
+ if (!(p = realloc(so->answer, size)))
+ return dns_syerr();
+
+ so->answer = dns_p_init(p, size);
+
+ return 0;
+} /* dns_so_newanswer() */
+
+
+int dns_so_submit(struct dns_socket *so, struct dns_packet *Q, struct sockaddr *host) {
+ struct dns_rr rr;
+ int error = DNS_EUNKNOWN;
+
+ dns_so_reset(so);
+
+ if ((error = dns_rr_parse(&rr, 12, Q)))
+ goto error;
+
+ if (!(so->qlen = dns_d_expand(so->qname, sizeof so->qname, rr.dn.p, Q, &error)))
+ goto error;
+ /*
+ * NOTE: Don't bail if expansion is too long; caller may be
+ * intentionally sending long names. However, we won't be able to
+ * verify it on return.
+ */
+
+ so->qtype = rr.type;
+ so->qclass = rr.class;
+
+ if ((error = dns_so_newanswer(so, (Q->memo.opt.maxudp)? Q->memo.opt.maxudp : DNS_SO_MINBUF)))
+ goto syerr;
+
+ memcpy(&so->remote, host, dns_sa_len(host));
+
+ so->query = Q;
+ so->qout = 0;
+
+ dns_begin(&so->elapsed);
+
+ if (dns_header(so->query)->qid == 0)
+ dns_header(so->query)->qid = dns_so_mkqid(so);
+
+ so->qid = dns_header(so->query)->qid;
+ so->state = (so->opts.socks_host && so->opts.socks_host->ss_family) ? DNS_SO_SOCKS_INIT :
+ (so->type == SOCK_STREAM)? DNS_SO_TCP_INIT : DNS_SO_UDP_INIT;
+
+ so->stat.queries++;
+ dns_trace_so_submit(so->trace, Q, host, 0);
+
+ return 0;
+syerr:
+ error = dns_syerr();
+error:
+ dns_so_reset(so);
+ dns_trace_so_submit(so->trace, Q, host, error);
+ return error;
+} /* dns_so_submit() */
+
+
+static int dns_so_verify(struct dns_socket *so, struct dns_packet *P) {
+ char qname[DNS_D_MAXNAME + 1];
+ size_t qlen;
+ struct dns_rr rr;
+ int error = -1;
+
+ if (P->end < 12)
+ goto reject;
+
+ if (so->qid != dns_header(P)->qid)
+ goto reject;
+
+ if (!dns_p_count(P, DNS_S_QD))
+ goto reject;
+
+ if (0 != dns_rr_parse(&rr, 12, P))
+ goto reject;
+
+ if (rr.type != so->qtype || rr.class != so->qclass)
+ goto reject;
+
+ if (!(qlen = dns_d_expand(qname, sizeof qname, rr.dn.p, P, &error)))
+ goto error;
+ else if (qlen >= sizeof qname || qlen != so->qlen)
+ goto reject;
+
+ if (0 != strcasecmp(so->qname, qname))
+ goto reject;
+
+ dns_trace_so_verify(so->trace, P, 0);
+
+ return 0;
+reject:
+ error = DNS_EVERIFY;
+error:
+ DNS_SHOW(P, "rejecting packet (%s)", dns_strerror(error));
+ dns_trace_so_verify(so->trace, P, error);
+
+ return error;
+} /* dns_so_verify() */
+
+
+static _Bool dns_so_tcp_keep(struct dns_socket *so) {
+ struct sockaddr_storage remote;
+
+ if (so->tcp == -1)
+ return 0;
+
+ if (0 != getpeername(so->tcp, (struct sockaddr *)&remote, &(socklen_t){ sizeof remote }))
+ return 0;
+
+ return 0 == dns_sa_cmp(&remote, &so->remote);
+} /* dns_so_tcp_keep() */
+
+
+#if defined __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Warray-bounds"
+#endif
+
+static int dns_so_tcp_send(struct dns_socket *so) {
+ unsigned char *qsrc;
+ size_t qend;
+ int error;
+ size_t n;
+
+ so->query->data[-2] = 0xff & (so->query->end >> 8);
+ so->query->data[-1] = 0xff & (so->query->end >> 0);
+
+ qend = so->query->end + 2;
+
+ while (so->qout < qend) {
+ qsrc = &so->query->data[-2] + so->qout;
+ n = dns_send_nopipe(so->tcp, (void *)qsrc, qend - so->qout, 0, &error);
+ dns_trace_sys_send(so->trace, so->tcp, SOCK_STREAM, qsrc, n, error);
+ if (error)
+ return error;
+ so->qout += n;
+ so->stat.tcp.sent.bytes += n;
+ }
+
+ so->stat.tcp.sent.count++;
+
+ return 0;
+} /* dns_so_tcp_send() */
+
+
+static int dns_so_tcp_recv(struct dns_socket *so) {
+ unsigned char *asrc;
+ size_t aend, alen, n;
+ int error;
+
+ aend = so->alen + 2;
+
+ while (so->apos < aend) {
+ asrc = &so->answer->data[-2];
+
+ n = dns_recv(so->tcp, (void *)&asrc[so->apos], aend - so->apos, 0, &error);
+ dns_trace_sys_recv(so->trace, so->tcp, SOCK_STREAM, &asrc[so->apos], n, error);
+ if (error)
+ return error;
+
+ so->apos += n;
+ so->stat.tcp.rcvd.bytes += n;
+
+ if (so->alen == 0 && so->apos >= 2) {
+ alen = ((0xff & so->answer->data[-2]) << 8)
+ | ((0xff & so->answer->data[-1]) << 0);
+
+ if ((error = dns_so_newanswer(so, alen)))
+ return error;
+
+ so->alen = alen;
+ aend = alen + 2;
+ }
+ }
+
+ so->answer->end = so->alen;
+ so->stat.tcp.rcvd.count++;
+
+ return 0;
+} /* dns_so_tcp_recv() */
+
+#if __clang__
+#pragma clang diagnostic pop
+#endif
+
+
+int dns_so_check(struct dns_socket *so) {
+ int error;
+ size_t n;
+
+ /* XXX */
+ unsigned char *buffer;
+ int method;
+
+retry:
+ switch (so->state) {
+ case DNS_SO_UDP_INIT:
+ so->state++;
+ case DNS_SO_UDP_CONN:
+ error = dns_connect(so->udp, (struct sockaddr *)&so->remote, dns_sa_len(&so->remote));
+ dns_trace_sys_connect(so->trace, so->udp, SOCK_DGRAM, (struct sockaddr *)&so->remote, error);
+ if (error)
+ goto error;
+
+ so->state++;
+ case DNS_SO_UDP_SEND:
+ n = dns_send(so->udp, (void *)so->query->data, so->query->end, 0, &error);
+ dns_trace_sys_send(so->trace, so->udp, SOCK_DGRAM, so->query->data, n, error);
+ if (error)
+ goto error;
+
+ so->stat.udp.sent.bytes += n;
+ so->stat.udp.sent.count++;
+
+ so->state++;
+ case DNS_SO_UDP_RECV:
+ n = dns_recv(so->udp, (void *)so->answer->data, so->answer->size, 0, &error);
+ dns_trace_sys_recv(so->trace, so->udp, SOCK_DGRAM, so->answer->data, n, error);
+ if (error)
+ goto error;
+
+ so->answer->end = n;
+ so->stat.udp.rcvd.bytes += n;
+ so->stat.udp.rcvd.count++;
+
+ if ((error = dns_so_verify(so, so->answer)))
+ goto trash;
+
+ so->state++;
+ case DNS_SO_UDP_DONE:
+ if (!dns_header(so->answer)->tc || so->type == SOCK_DGRAM)
+ return 0;
+
+ so->state++;
+ case DNS_SO_TCP_INIT:
+ if (dns_so_tcp_keep(so)) {
+ so->state = DNS_SO_TCP_SEND;
+
+ goto retry;
+ }
+
+ if ((error = dns_so_closefd(so, &so->tcp)))
+ goto error;
+
+ if (-1 == (so->tcp = dns_socket((struct sockaddr *)&so->local, SOCK_STREAM, &error)))
+ goto error;
+
+ so->state++;
+ case DNS_SO_TCP_CONN:
+ error = dns_connect(so->tcp, (struct sockaddr *)&so->remote, dns_sa_len(&so->remote));
+ dns_trace_sys_connect(so->trace, so->tcp, SOCK_STREAM, (struct sockaddr *)&so->remote, error);
+ if (error && error != DNS_EISCONN)
+ goto error;
+
+ so->state++;
+ case DNS_SO_TCP_SEND:
+ if ((error = dns_so_tcp_send(so)))
+ goto error;
+
+ so->state++;
+ case DNS_SO_TCP_RECV:
+ if ((error = dns_so_tcp_recv(so)))
+ goto error;
+
+ so->state++;
+ case DNS_SO_TCP_DONE:
+ /* close unless DNS_RESCONF_TCP_ONLY (see dns_res_tcp2type) */
+ if (so->type != SOCK_STREAM) {
+ if ((error = dns_so_closefd(so, &so->tcp)))
+ goto error;
+ }
+
+ if ((error = dns_so_verify(so, so->answer)))
+ goto error;
+
+ return 0;
+ case DNS_SO_SOCKS_INIT:
+ if ((error = dns_so_closefd(so, &so->tcp)))
+ goto error;
+
+ if (-1 == (so->tcp = dns_socket((struct sockaddr *)&so->local, SOCK_STREAM, &error)))
+ goto error;
+
+ so->state++;
+ case DNS_SO_SOCKS_CONN:
+ error = dns_connect(so->tcp, (struct sockaddr *)so->opts.socks_host, dns_sa_len(so->opts.socks_host));
+ dns_trace_sys_connect(so->trace, so->tcp, SOCK_STREAM, (struct sockaddr *)so->opts.socks_host, error);
+ if (error && error != DNS_EISCONN)
+ goto error;
+
+ /* We need to do a handshake with the SOCKS server,
+ * but the query is already in the buffer. Move it
+ * out of the way. */
+ dns_p_movptr(&so->query_backup, &so->query);
+
+ /* Create a new buffer for the handshake. */
+ dns_p_grow(&so->query);
+
+ /* Skip the two octets length field when
+ transmitting, send three octets. */
+ so->qout = 2;
+ so->query->end = 3;
+ buffer = so->query->data;
+
+ /* Negotiate method. */
+ buffer[0] = 5; /* RFC-1928 VER field. */
+ buffer[1] = 1; /* NMETHODS */
+ if (0 /* XXX */)
+ method = 2; /* Method: username/password authentication. */
+ else
+ method = 0; /* Method: No authentication required. */
+ buffer[2] = method;
+
+ so->state++;
+ case DNS_SO_SOCKS_AUTH_SEND:
+ if ((error = dns_so_tcp_send(so)))
+ goto error;
+
+ /* Skip the two length octets, and receive two octets. */
+ so->apos = 2;
+ so->alen = 2;
+
+ so->state++;
+ case DNS_SO_SOCKS_AUTH_RECV:
+ if ((error = dns_so_tcp_recv(so)))
+ goto error;
+
+ buffer = so->answer->data;
+ method = 0; /* XXX authentication not yet supported */
+ if (buffer[0] != 5 || buffer[1] != method) {
+ /* Socks server returned wrong version or does
+ not support our requested method. */
+ error = ENOTSUP; /* Fixme: Is there a better errno? */
+ goto error;
+ }
+
+ /* Skip the two octets length field when
+ transmitting. */
+ so->qout = 2;
+ buffer = so->query->data;
+
+ /* Send request details (rfc-1928, 4). */
+ buffer[0] = 5; /* VER */
+ buffer[1] = 1; /* CMD = CONNECT */
+ buffer[2] = 0; /* RSV */
+ if (so->remote.ss_family == AF_INET6) {
+ struct sockaddr_in6 *addr_in6 = (struct sockaddr_in6 *)&so->remote;
+
+ buffer[3] = 4; /* ATYP = IPv6 */
+ memcpy (buffer+ 4, &addr_in6->sin6_addr.s6_addr, 16); /* DST.ADDR */
+ memcpy (buffer+20, &addr_in6->sin6_port, 2); /* DST.PORT */
+ so->query->end = 22;
+ } else {
+ struct sockaddr_in *addr_in = (struct sockaddr_in *)&so->remote;
+
+ buffer[3] = 1; /* ATYP = IPv4 */
+ memcpy (buffer+4, &addr_in->sin_addr.s_addr, 4); /* DST.ADDR */
+ memcpy (buffer+8, &addr_in->sin_port, 2); /* DST.PORT */
+ so->query->end = 10;
+ }
+
+ so->state++;
+ case DNS_SO_SOCKS_REQUEST_SEND:
+ if ((error = dns_so_tcp_send(so)))
+ goto error;
+
+ /* Skip the two length octets, and receive ten octets.
+ * This is the length of the response assuming a IPv4
+ * address is used. */
+ so->apos = 2;
+ so->alen = 10;
+
+ so->state++;
+ case DNS_SO_SOCKS_REQUEST_RECV:
+ if ((error = dns_so_tcp_recv(so)))
+ goto error;
+
+ buffer = so->answer->data;
+ if (buffer[0] != 5 || buffer[2] != 0 ) {
+ /* Socks server returned wrong version or the
+ reserved field is not zero. */
+ error = EPROTO;
+ goto error;
+ }
+ if (buffer[1]) {
+ switch (buffer[1]) {
+ case 0x01: /* general SOCKS server failure. */
+ error = ENETDOWN;
+ break;
+ case 0x02: /* connection not allowed by ruleset. */
+ error = EACCES;
+ break;
+ case 0x03: /* Network unreachable */
+ error = ENETUNREACH;
+ break;
+ case 0x04: /* Host unreachable */
+ error = EHOSTUNREACH;
+ break;
+ case 0x05: /* Connection refused */
+ error = ECONNREFUSED;
+ break;
+ case 0x06: /* TTL expired */
+ error = ETIMEDOUT;
+ break;
+ case 0x08: /* Address type not supported */
+ error = EPROTONOSUPPORT;
+ break;
+ case 0x07: /* Command not supported */
+ default:
+ error = ENOTSUP; /* Fixme: Is there a better error? */
+ break;
+ }
+ goto error;
+ }
+
+ if (buffer[3] == 1) {
+ /* This was indeed an IPv4 address. */
+ so->state = DNS_SO_SOCKS_HANDSHAKE_DONE;
+ goto retry;
+ }
+
+ if (buffer[3] != 4) {
+ error = ENOTSUP;
+ goto error;
+ }
+
+ /* ATYP indicates a v6 address. Skip the two length
+ * octets, and receive twelve octets. This accounts
+ * for the remaining bytes assuming an IPv6 address is
+ * used. */
+ so->apos = 2;
+ so->alen = 12;
+
+ so->state++;
+ case DNS_SO_SOCKS_REQUEST_RECV_V6:
+ if ((error = dns_so_tcp_recv(so)))
+ goto error;
+
+ so->state++;
+ case DNS_SO_SOCKS_HANDSHAKE_DONE:
+ /* We have not way to store the actual address used by
+ * the server. Then again, we don't really care. */
+
+ /* Restore the query. */
+ dns_p_movptr(&so->query, &so->query_backup);
+
+ /* Reset cursors. */
+ so->qout = 0;
+ so->apos = 0;
+ so->alen = 0;
+
+ /* SOCKS handshake is done. Proceed with the
+ * lookup. */
+ so->state = DNS_SO_TCP_SEND;
+ goto retry;
+ default:
+ error = DNS_EUNKNOWN;
+
+ goto error;
+ } /* switch() */
+
+trash:
+ DNS_CARP("discarding packet");
+ goto retry;
+error:
+ switch (error) {
+ case DNS_EINTR:
+ goto retry;
+ case DNS_EINPROGRESS:
+ /* FALL THROUGH */
+ case DNS_EALREADY:
+ /* FALL THROUGH */
+#if DNS_EWOULDBLOCK != DNS_EAGAIN
+ case DNS_EWOULDBLOCK:
+ /* FALL THROUGH */
+#endif
+ error = DNS_EAGAIN;
+
+ break;
+ } /* switch() */
+
+ return error;
+} /* dns_so_check() */
+
+
+struct dns_packet *dns_so_fetch(struct dns_socket *so, int *error) {
+ struct dns_packet *answer;
+
+ switch (so->state) {
+ case DNS_SO_UDP_DONE:
+ case DNS_SO_TCP_DONE:
+ answer = so->answer;
+ so->answer = 0;
+ dns_trace_so_fetch(so->trace, answer, 0);
+
+ return answer;
+ default:
+ *error = DNS_EUNKNOWN;
+ dns_trace_so_fetch(so->trace, NULL, *error);
+
+ return 0;
+ }
+} /* dns_so_fetch() */
+
+
+struct dns_packet *dns_so_query(struct dns_socket *so, struct dns_packet *Q, struct sockaddr *host, int *error_) {
+ struct dns_packet *A;
+ int error;
+
+ if (!so->state) {
+ if ((error = dns_so_submit(so, Q, host)))
+ goto error;
+ }
+
+ if ((error = dns_so_check(so)))
+ goto error;
+
+ if (!(A = dns_so_fetch(so, &error)))
+ goto error;
+
+ dns_so_reset(so);
+
+ return A;
+error:
+ *error_ = error;
+
+ return 0;
+} /* dns_so_query() */
+
+
+time_t dns_so_elapsed(struct dns_socket *so) {
+ return dns_elapsed(&so->elapsed);
+} /* dns_so_elapsed() */
+
+
+void dns_so_clear(struct dns_socket *so) {
+ dns_so_closefds(so, DNS_SO_CLOSE_OLD);
+} /* dns_so_clear() */
+
+
+static int dns_so_events2(struct dns_socket *so, enum dns_events type) {
+ int events = 0;
+
+ switch (so->state) {
+ case DNS_SO_UDP_CONN:
+ case DNS_SO_UDP_SEND:
+ events |= DNS_POLLOUT;
+
+ break;
+ case DNS_SO_UDP_RECV:
+ events |= DNS_POLLIN;
+
+ break;
+ case DNS_SO_TCP_CONN:
+ case DNS_SO_TCP_SEND:
+ events |= DNS_POLLOUT;
+
+ break;
+ case DNS_SO_TCP_RECV:
+ events |= DNS_POLLIN;
+
+ break;
+ } /* switch() */
+
+ switch (type) {
+ case DNS_LIBEVENT:
+ return DNS_POLL2EV(events);
+ default:
+ return events;
+ } /* switch() */
+} /* dns_so_events2() */
+
+
+int dns_so_events(struct dns_socket *so) {
+ return dns_so_events2(so, so->opts.events);
+} /* dns_so_events() */
+
+
+int dns_so_pollfd(struct dns_socket *so) {
+ switch (so->state) {
+ case DNS_SO_UDP_CONN:
+ case DNS_SO_UDP_SEND:
+ case DNS_SO_UDP_RECV:
+ return so->udp;
+ case DNS_SO_TCP_CONN:
+ case DNS_SO_TCP_SEND:
+ case DNS_SO_TCP_RECV:
+ return so->tcp;
+ } /* switch() */
+
+ return -1;
+} /* dns_so_pollfd() */
+
+
+int dns_so_poll(struct dns_socket *so, int timeout) {
+ return dns_poll(dns_so_pollfd(so), dns_so_events2(so, DNS_SYSPOLL), timeout);
+} /* dns_so_poll() */
+
+
+const struct dns_stat *dns_so_stat(struct dns_socket *so) {
+ return &so->stat;
+} /* dns_so_stat() */
+
+
+struct dns_trace *dns_so_trace(struct dns_socket *so) {
+ return so->trace;
+} /* dns_so_trace() */
+
+
+void dns_so_settrace(struct dns_socket *so, struct dns_trace *trace) {
+ struct dns_trace *otrace = so->trace;
+ so->trace = dns_trace_acquire_p(trace);
+ dns_trace_close(otrace);
+} /* dns_so_settrace() */
+
+
+/*
+ * R E S O L V E R R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+enum dns_res_state {
+ DNS_R_INIT,
+ DNS_R_GLUE,
+ DNS_R_SWITCH, /* (B)IND, (F)ILE, (C)ACHE */
+
+ DNS_R_FILE, /* Lookup in local hosts database */
+
+ DNS_R_CACHE, /* Lookup in application cache */
+ DNS_R_SUBMIT,
+ DNS_R_CHECK,
+ DNS_R_FETCH,
+
+ DNS_R_BIND, /* Lookup in the network */
+ DNS_R_SEARCH,
+ DNS_R_HINTS,
+ DNS_R_ITERATE,
+ DNS_R_FOREACH_NS,
+ DNS_R_RESOLV0_NS, /* Prologue: Setup next frame and recurse */
+ DNS_R_RESOLV1_NS, /* Epilog: Inspect answer */
+ DNS_R_FOREACH_A,
+ DNS_R_QUERY_A,
+ DNS_R_CNAME0_A,
+ DNS_R_CNAME1_A,
+
+ DNS_R_FINISH,
+ DNS_R_SMART0_A,
+ DNS_R_SMART1_A,
+ DNS_R_DONE,
+ DNS_R_SERVFAIL,
+}; /* enum dns_res_state */
+
+
+#define DNS_R_MAXDEPTH 8
+#define DNS_R_ENDFRAME (DNS_R_MAXDEPTH - 1)
+
+struct dns_resolver {
+ struct dns_socket so;
+
+ struct dns_resolv_conf *resconf;
+ struct dns_hosts *hosts;
+ struct dns_hints *hints;
+ struct dns_cache *cache;
+ struct dns_trace *trace;
+
+ dns_atomic_t refcount;
+
+ /* Reset zeroes everything below here. */
+
+ char qname[DNS_D_MAXNAME + 1];
+ size_t qlen;
+
+ enum dns_type qtype;
+ enum dns_class qclass;
+
+ struct dns_clock elapsed;
+
+ dns_resconf_i_t search;
+
+ struct dns_rr_i smart;
+
+ struct dns_packet *nodata; /* answer if nothing better */
+
+ unsigned sp;
+
+ struct dns_res_frame {
+ enum dns_res_state state;
+
+ int error;
+ int which; /* (B)IND, (F)ILE; index into resconf->lookup */
+ int qflags;
+
+ unsigned attempts;
+
+ struct dns_packet *query, *answer, *hints;
+
+ struct dns_rr_i hints_i, hints_j;
+ struct dns_rr hints_ns, ans_cname;
+ } stack[DNS_R_MAXDEPTH];
+}; /* struct dns_resolver */
+
+
+static int dns_res_tcp2type(int tcp) {
+ switch (tcp) {
+ case DNS_RESCONF_TCP_ONLY:
+ case DNS_RESCONF_TCP_SOCKS:
+ return SOCK_STREAM;
+ case DNS_RESCONF_TCP_DISABLE:
+ return SOCK_DGRAM;
+ default:
+ return 0;
+ }
+} /* dns_res_tcp2type() */
+
+struct dns_resolver *dns_res_open(struct dns_resolv_conf *resconf, struct dns_hosts *hosts, struct dns_hints *hints, struct dns_cache *cache, const struct dns_options *opts, int *_error) {
+ static const struct dns_resolver R_initializer
+ = { .refcount = 1, };
+ struct dns_resolver *R = 0;
+ int type, error;
+
+ /*
+ * Grab ref count early because the caller may have passed us a mortal
+ * reference, and we want to do the right thing if we return early
+ * from an error.
+ */
+ if (resconf)
+ dns_resconf_acquire(resconf);
+ if (hosts)
+ dns_hosts_acquire(hosts);
+ if (hints)
+ dns_hints_acquire(hints);
+ if (cache)
+ dns_cache_acquire(cache);
+
+ /*
+ * Don't try to load it ourselves because a NULL object might be an
+ * error from, say, dns_resconf_root(), and loading
+ * dns_resconf_local() by default would create undesirable surpises.
+ */
+ if (!resconf || !hosts || !hints) {
+ if (!*_error)
+ *_error = EINVAL;
+ goto _error;
+ }
+
+ if (!(R = malloc(sizeof *R)))
+ goto syerr;
+
+ *R = R_initializer;
+ type = dns_res_tcp2type(resconf->options.tcp);
+
+ if (!dns_so_init(&R->so, (struct sockaddr *)&resconf->iface, type, opts, &error))
+ goto error;
+
+ R->resconf = resconf;
+ R->hosts = hosts;
+ R->hints = hints;
+ R->cache = cache;
+
+ return R;
+syerr:
+ error = dns_syerr();
+error:
+ *_error = error;
+_error:
+ dns_res_close(R);
+
+ dns_resconf_close(resconf);
+ dns_hosts_close(hosts);
+ dns_hints_close(hints);
+ dns_cache_close(cache);
+
+ return 0;
+} /* dns_res_open() */
+
+
+struct dns_resolver *dns_res_stub(const struct dns_options *opts, int *error) {
+ struct dns_resolv_conf *resconf = 0;
+ struct dns_hosts *hosts = 0;
+ struct dns_hints *hints = 0;
+ struct dns_resolver *res = 0;
+
+ if (!(resconf = dns_resconf_local(error)))
+ goto epilog;
+
+ if (!(hosts = dns_hosts_local(error)))
+ goto epilog;
+
+ if (!(hints = dns_hints_local(resconf, error)))
+ goto epilog;
+
+ if (!(res = dns_res_open(resconf, hosts, hints, NULL, opts, error)))
+ goto epilog;
+
+epilog:
+ dns_resconf_close(resconf);
+ dns_hosts_close(hosts);
+ dns_hints_close(hints);
+
+ return res;
+} /* dns_res_stub() */
+
+
+static void dns_res_frame_destroy(struct dns_resolver *R, struct dns_res_frame *frame) {
+ (void)R;
+
+ dns_p_setptr(&frame->query, NULL);
+ dns_p_setptr(&frame->answer, NULL);
+ dns_p_setptr(&frame->hints, NULL);
+} /* dns_res_frame_destroy() */
+
+
+static void dns_res_frame_init(struct dns_resolver *R, struct dns_res_frame *frame) {
+ memset(frame, '\0', sizeof *frame);
+
+ /*
+ * NB: Can be invoked from dns_res_open, before R->resconf has been
+ * initialized.
+ */
+ if (R->resconf) {
+ if (!R->resconf->options.recurse)
+ frame->qflags |= DNS_Q_RD;
+ if (R->resconf->options.edns0)
+ frame->qflags |= DNS_Q_EDNS0;
+ }
+} /* dns_res_frame_init() */
+
+
+static void dns_res_frame_reset(struct dns_resolver *R, struct dns_res_frame *frame) {
+ dns_res_frame_destroy(R, frame);
+ dns_res_frame_init(R, frame);
+} /* dns_res_frame_reset() */
+
+
+static dns_error_t dns_res_frame_prepare(struct dns_resolver *R, struct dns_res_frame *F, const char *qname, enum dns_type qtype, enum dns_class qclass) {
+ struct dns_packet *P = NULL;
+
+ if (!(F < endof(R->stack)))
+ return DNS_EUNKNOWN;
+
+ dns_p_movptr(&P, &F->query);
+ dns_res_frame_reset(R, F);
+ dns_p_movptr(&F->query, &P);
+
+ return dns_q_make(&F->query, qname, qtype, qclass, F->qflags);
+} /* dns_res_frame_prepare() */
+
+
+void dns_res_reset(struct dns_resolver *R) {
+ unsigned i;
+
+ dns_so_reset(&R->so);
+ dns_p_setptr(&R->nodata, NULL);
+
+ for (i = 0; i < lengthof(R->stack); i++)
+ dns_res_frame_destroy(R, &R->stack[i]);
+
+ memset(&R->qname, '\0', sizeof *R - offsetof(struct dns_resolver, qname));
+
+ for (i = 0; i < lengthof(R->stack); i++)
+ dns_res_frame_init(R, &R->stack[i]);
+} /* dns_res_reset() */
+
+
+void dns_res_close(struct dns_resolver *R) {
+ if (!R || 1 < dns_res_release(R))
+ return;
+
+ dns_res_reset(R);
+
+ dns_so_destroy(&R->so);
+
+ dns_hints_close(R->hints);
+ dns_hosts_close(R->hosts);
+ dns_resconf_close(R->resconf);
+ dns_cache_close(R->cache);
+ dns_trace_close(R->trace);
+
+ free(R);
+} /* dns_res_close() */
+
+
+dns_refcount_t dns_res_acquire(struct dns_resolver *R) {
+ return dns_atomic_fetch_add(&R->refcount);
+} /* dns_res_acquire() */
+
+
+dns_refcount_t dns_res_release(struct dns_resolver *R) {
+ return dns_atomic_fetch_sub(&R->refcount);
+} /* dns_res_release() */
+
+
+struct dns_resolver *dns_res_mortal(struct dns_resolver *res) {
+ if (res)
+ dns_res_release(res);
+ return res;
+} /* dns_res_mortal() */
+
+
+static struct dns_packet *dns_res_merge(struct dns_packet *P0, struct dns_packet *P1, int *error_) {
+ size_t bufsiz = P0->end + P1->end;
+ struct dns_packet *P[3] = { P0, P1, 0 };
+ struct dns_rr rr[3];
+ int error, copy, i;
+ enum dns_section section;
+
+retry:
+ if (!(P[2] = dns_p_make(bufsiz, &error)))
+ goto error;
+
+ dns_rr_foreach(&rr[0], P[0], .section = DNS_S_QD) {
+ if ((error = dns_rr_copy(P[2], &rr[0], P[0])))
+ goto error;
+ }
+
+ for (section = DNS_S_AN; (DNS_S_ALL & section); section <<= 1) {
+ for (i = 0; i < 2; i++) {
+ dns_rr_foreach(&rr[i], P[i], .section = section) {
+ copy = 1;
+
+ dns_rr_foreach(&rr[2], P[2], .type = rr[i].type, .section = (DNS_S_ALL & ~DNS_S_QD)) {
+ if (0 == dns_rr_cmp(&rr[i], P[i], &rr[2], P[2])) {
+ copy = 0;
+
+ break;
+ }
+ }
+
+ if (copy && (error = dns_rr_copy(P[2], &rr[i], P[i]))) {
+ if (error == DNS_ENOBUFS && bufsiz < 65535) {
+ dns_p_setptr(&P[2], NULL);
+
+ bufsiz = DNS_PP_MAX(65535, bufsiz * 2);
+
+ goto retry;
+ }
+
+ goto error;
+ }
+ } /* foreach(rr) */
+ } /* foreach(packet) */
+ } /* foreach(section) */
+
+ return P[2];
+error:
+ *error_ = error;
+
+ dns_p_free(P[2]);
+
+ return 0;
+} /* dns_res_merge() */
+
+
+static struct dns_packet *dns_res_glue(struct dns_resolver *R, struct dns_packet *Q) {
+ struct dns_packet *P = dns_p_new(512);
+ char qname[DNS_D_MAXNAME + 1];
+ size_t qlen;
+ enum dns_type qtype;
+ struct dns_rr rr;
+ unsigned sp;
+ int error;
+
+ if (!(qlen = dns_d_expand(qname, sizeof qname, 12, Q, &error))
+ || qlen >= sizeof qname)
+ return 0;
+
+ if (!(qtype = dns_rr_type(12, Q)))
+ return 0;
+
+ if ((error = dns_p_push(P, DNS_S_QD, qname, strlen(qname), qtype, DNS_C_IN, 0, 0)))
+ return 0;
+
+ for (sp = 0; sp <= R->sp; sp++) {
+ if (!R->stack[sp].answer)
+ continue;
+
+ dns_rr_foreach(&rr, R->stack[sp].answer, .name = qname, .type = qtype, .section = (DNS_S_ALL & ~DNS_S_QD)) {
+ rr.section = DNS_S_AN;
+
+ if ((error = dns_rr_copy(P, &rr, R->stack[sp].answer)))
+ return 0;
+ }
+ }
+
+ if (dns_p_count(P, DNS_S_AN) > 0)
+ goto copy;
+
+ /* Otherwise, look for a CNAME */
+ for (sp = 0; sp <= R->sp; sp++) {
+ if (!R->stack[sp].answer)
+ continue;
+
+ dns_rr_foreach(&rr, R->stack[sp].answer, .name = qname, .type = DNS_T_CNAME, .section = (DNS_S_ALL & ~DNS_S_QD)) {
+ rr.section = DNS_S_AN;
+
+ if ((error = dns_rr_copy(P, &rr, R->stack[sp].answer)))
+ return 0;
+ }
+ }
+
+ if (!dns_p_count(P, DNS_S_AN))
+ return 0;
+
+copy:
+ return dns_p_copy(dns_p_make(P->end, &error), P);
+} /* dns_res_glue() */
+
+
+/*
+ * Sort NS records by three criteria:
+ *
+ * 1) Whether glue is present.
+ * 2) Whether glue record is original or of recursive lookup.
+ * 3) Randomly shuffle records which share the above criteria.
+ *
+ * NOTE: Assumes only NS records passed, AND ASSUMES no new NS records will
+ * be added during an iteration.
+ *
+ * FIXME: Only groks A glue, not AAAA glue.
+ */
+static int dns_res_nameserv_cmp(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) {
+ _Bool glued[2] = { 0 };
+ struct dns_rr x = { 0 }, y = { 0 };
+ struct dns_ns ns;
+ int cmp, error;
+
+ if (!(error = dns_ns_parse(&ns, a, P)))
+ glued[0] = !!dns_rr_grep(&x, 1, dns_rr_i_new(P, .section = (DNS_S_ALL & ~DNS_S_QD), .name = ns.host, .type = DNS_T_A), P, &error);
+
+ if (!(error = dns_ns_parse(&ns, b, P)))
+ glued[1] = !!dns_rr_grep(&y, 1, dns_rr_i_new(P, .section = (DNS_S_ALL & ~DNS_S_QD), .name = ns.host, .type = DNS_T_A), P, &error);
+
+ if ((cmp = glued[1] - glued[0])) {
+ return cmp;
+ } else if ((cmp = (dns_rr_offset(&y) < i->args[0]) - (dns_rr_offset(&x) < i->args[0]))) {
+ return cmp;
+ } else {
+ return dns_rr_i_shuffle(a, b, i, P);
+ }
+} /* dns_res_nameserv_cmp() */
+
+
+#define dgoto(sp, i) \
+ do { R->stack[(sp)].state = (i); goto exec; } while (0)
+
+static int dns_res_exec(struct dns_resolver *R) {
+ struct dns_res_frame *F;
+ struct dns_packet *P;
+ union {
+ char host[DNS_D_MAXNAME + 1];
+ char name[DNS_D_MAXNAME + 1];
+ struct dns_ns ns;
+ struct dns_cname cname;
+ } u;
+ size_t len;
+ struct dns_rr rr;
+ int error;
+
+exec:
+
+ F = &R->stack[R->sp];
+
+ switch (F->state) {
+ case DNS_R_INIT:
+ F->state++;
+ case DNS_R_GLUE:
+ if (R->sp == 0)
+ dgoto(R->sp, DNS_R_SWITCH);
+
+ if (!F->query)
+ goto noquery;
+
+ if (!(F->answer = dns_res_glue(R, F->query)))
+ dgoto(R->sp, DNS_R_SWITCH);
+
+ if (!(len = dns_d_expand(u.name, sizeof u.name, 12, F->query, &error)))
+ goto error;
+ else if (len >= sizeof u.name)
+ goto toolong;
+
+ dns_rr_foreach(&rr, F->answer, .name = u.name, .type = dns_rr_type(12, F->query), .section = DNS_S_AN) {
+ dgoto(R->sp, DNS_R_FINISH);
+ }
+
+ dns_rr_foreach(&rr, F->answer, .name = u.name, .type = DNS_T_CNAME, .section = DNS_S_AN) {
+ F->ans_cname = rr;
+
+ dgoto(R->sp, DNS_R_CNAME0_A);
+ }
+
+ F->state++;
+ case DNS_R_SWITCH:
+ while (F->which < (int)sizeof R->resconf->lookup && R->resconf->lookup[F->which]) {
+ switch (R->resconf->lookup[F->which++]) {
+ case 'b': case 'B':
+ dgoto(R->sp, DNS_R_BIND);
+ case 'f': case 'F':
+ dgoto(R->sp, DNS_R_FILE);
+ case 'c': case 'C':
+ if (R->cache)
+ dgoto(R->sp, DNS_R_CACHE);
+
+ break;
+ default:
+ break;
+ }
+ }
+
+ /*
+ * FIXME: Examine more closely whether our logic is correct
+ * and DNS_R_SERVFAIL is the correct default response.
+ *
+ * Case 1: We got here because we never got an answer on the
+ * wire. All queries timed-out and we reached maximum
+ * attempts count. See DNS_R_FOREACH_NS. In that case
+ * DNS_R_SERVFAIL is the correct state, unless we want to
+ * return DNS_ETIMEDOUT.
+ *
+ * Case 2: We were a stub resolver and got an unsatisfactory
+ * answer (empty ANSWER section) which caused us to jump
+ * back to DNS_R_SEARCH and ultimately to DNS_R_SWITCH. We
+ * return the answer returned from the wire, which we
+ * stashed in R->nodata.
+ *
+ * Case 3: We reached maximum attempts count as in case #1,
+ * but never got an authoritative response which caused us
+ * to short-circuit. See end of DNS_R_QUERY_A case. We
+ * should probably prepare R->nodata as in case #2.
+ */
+ if (R->sp == 0 && R->nodata) { /* XXX: can we just return nodata regardless? */
+ dns_p_movptr(&F->answer, &R->nodata);
+ dgoto(R->sp, DNS_R_FINISH);
+ }
+
+ dgoto(R->sp, DNS_R_SERVFAIL);
+ case DNS_R_FILE:
+ if (R->sp > 0) {
+ if (!dns_p_setptr(&F->answer, dns_hosts_query(R->hosts, F->query, &error)))
+ goto error;
+
+ if (dns_p_count(F->answer, DNS_S_AN) > 0)
+ dgoto(R->sp, DNS_R_FINISH);
+
+ dns_p_setptr(&F->answer, NULL);
+ } else {
+ R->search = 0;
+
+ while ((len = dns_resconf_search(u.name, sizeof u.name, R->qname, R->qlen, R->resconf, &R->search))) {
+ if ((error = dns_q_make2(&F->query, u.name, len, R->qtype, R->qclass, F->qflags)))
+ goto error;
+
+ if (!dns_p_setptr(&F->answer, dns_hosts_query(R->hosts, F->query, &error)))
+ goto error;
+
+ if (dns_p_count(F->answer, DNS_S_AN) > 0)
+ dgoto(R->sp, DNS_R_FINISH);
+
+ dns_p_setptr(&F->answer, NULL);
+ }
+ }
+
+ dgoto(R->sp, DNS_R_SWITCH);
+ case DNS_R_CACHE:
+ error = 0;
+
+ if (!F->query && (error = dns_q_make(&F->query, R->qname, R->qtype, R->qclass, F->qflags)))
+ goto error;
+
+ if (dns_p_setptr(&F->answer, R->cache->query(F->query, R->cache, &error))) {
+ if (dns_p_count(F->answer, DNS_S_AN) > 0)
+ dgoto(R->sp, DNS_R_FINISH);
+
+ dns_p_setptr(&F->answer, NULL);
+
+ dgoto(R->sp, DNS_R_SWITCH);
+ } else if (error)
+ goto error;
+
+ F->state++;
+ case DNS_R_SUBMIT:
+ if ((error = R->cache->submit(F->query, R->cache)))
+ goto error;
+
+ F->state++;
+ case DNS_R_CHECK:
+ if ((error = R->cache->check(R->cache)))
+ goto error;
+
+ F->state++;
+ case DNS_R_FETCH:
+ error = 0;
+
+ if (dns_p_setptr(&F->answer, R->cache->fetch(R->cache, &error))) {
+ if (dns_p_count(F->answer, DNS_S_AN) > 0)
+ dgoto(R->sp, DNS_R_FINISH);
+
+ dns_p_setptr(&F->answer, NULL);
+
+ dgoto(R->sp, DNS_R_SWITCH);
+ } else if (error)
+ goto error;
+
+ dgoto(R->sp, DNS_R_SWITCH);
+ case DNS_R_BIND:
+ if (R->sp > 0) {
+ if (!F->query)
+ goto noquery;
+
+ dgoto(R->sp, DNS_R_HINTS);
+ }
+
+ R->search = 0;
+
+ F->state++;
+ case DNS_R_SEARCH:
+ /*
+ * XXX: We probably should only apply the domain search
+ * algorithm if R->sp == 0.
+ */
+ if (!(len = dns_resconf_search(u.name, sizeof u.name, R->qname, R->qlen, R->resconf, &R->search)))
+ dgoto(R->sp, DNS_R_SWITCH);
+
+ if ((error = dns_q_make2(&F->query, u.name, len, R->qtype, R->qclass, F->qflags)))
+ goto error;
+
+ F->state++;
+ case DNS_R_HINTS:
+ if (!dns_p_setptr(&F->hints, dns_hints_query(R->hints, F->query, &error)))
+ goto error;
+
+ F->state++;
+ case DNS_R_ITERATE:
+ dns_rr_i_init(&F->hints_i, F->hints);
+
+ F->hints_i.section = DNS_S_AUTHORITY;
+ F->hints_i.type = DNS_T_NS;
+ F->hints_i.sort = &dns_res_nameserv_cmp;
+ F->hints_i.args[0] = F->hints->end;
+
+ F->state++;
+ case DNS_R_FOREACH_NS:
+ dns_rr_i_save(&F->hints_i);
+
+ /* Load our next nameserver host. */
+ if (!dns_rr_grep(&F->hints_ns, 1, &F->hints_i, F->hints, &error)) {
+ if (++F->attempts < R->resconf->options.attempts)
+ dgoto(R->sp, DNS_R_ITERATE);
+
+ dgoto(R->sp, DNS_R_SWITCH);
+ }
+
+ dns_rr_i_init(&F->hints_j, F->hints);
+
+ /* Assume there are glue records */
+ dgoto(R->sp, DNS_R_FOREACH_A);
+ case DNS_R_RESOLV0_NS:
+ /* Have we reached our max depth? */
+ if (&F[1] >= endof(R->stack))
+ dgoto(R->sp, DNS_R_FOREACH_NS);
+
+ if ((error = dns_ns_parse(&u.ns, &F->hints_ns, F->hints)))
+ goto error;
+ if ((error = dns_res_frame_prepare(R, &F[1], u.ns.host, DNS_T_A, DNS_C_IN)))
+ goto error;
+
+ F->state++;
+
+ dgoto(++R->sp, DNS_R_INIT);
+ case DNS_R_RESOLV1_NS:
+ if (!(len = dns_d_expand(u.host, sizeof u.host, 12, F[1].query, &error)))
+ goto error;
+ else if (len >= sizeof u.host)
+ goto toolong;
+
+ dns_rr_foreach(&rr, F[1].answer, .name = u.host, .type = DNS_T_A, .section = (DNS_S_ALL & ~DNS_S_QD)) {
+ rr.section = DNS_S_AR;
+
+ if ((error = dns_rr_copy(F->hints, &rr, F[1].answer)))
+ goto error;
+
+ dns_rr_i_rewind(&F->hints_i); /* Now there's glue. */
+ }
+
+ dgoto(R->sp, DNS_R_FOREACH_NS);
+ case DNS_R_FOREACH_A: {
+ struct dns_a a;
+ struct sockaddr_in sin;
+
+ /*
+ * NOTE: Iterator initialized in DNS_R_FOREACH_NS because
+ * this state is re-entrant, but we need to reset
+ * .name to a valid pointer each time.
+ */
+ if ((error = dns_ns_parse(&u.ns, &F->hints_ns, F->hints)))
+ goto error;
+
+ F->hints_j.name = u.ns.host;
+ F->hints_j.type = DNS_T_A;
+ F->hints_j.section = DNS_S_ALL & ~DNS_S_QD;
+
+ if (!dns_rr_grep(&rr, 1, &F->hints_j, F->hints, &error)) {
+ if (!dns_rr_i_count(&F->hints_j))
+ dgoto(R->sp, DNS_R_RESOLV0_NS);
+
+ dgoto(R->sp, DNS_R_FOREACH_NS);
+ }
+
+ if ((error = dns_a_parse(&a, &rr, F->hints)))
+ goto error;
+
+ memset(&sin, '\0', sizeof sin); /* NB: silence valgrind */
+ sin.sin_family = AF_INET;
+ sin.sin_addr = a.addr;
+ if (R->sp == 0)
+ sin.sin_port = dns_hints_port(R->hints, AF_INET, &sin.sin_addr);
+ else
+ sin.sin_port = htons(53);
+
+ if (DNS_DEBUG) {
+ char addr[INET_ADDRSTRLEN + 1];
+ dns_a_print(addr, sizeof addr, &a);
+ dns_header(F->query)->qid = dns_so_mkqid(&R->so);
+ DNS_SHOW(F->query, "ASKING: %s/%s @ DEPTH: %u)", u.ns.host, addr, R->sp);
+ }
+
+ dns_trace_setcname(R->trace, u.ns.host, (struct sockaddr *)&sin);
+
+ if ((error = dns_so_submit(&R->so, F->query, (struct sockaddr *)&sin)))
+ goto error;
+
+ F->state++;
+ }
+ case DNS_R_QUERY_A:
+ if (dns_so_elapsed(&R->so) >= dns_resconf_timeout(R->resconf))
+ dgoto(R->sp, DNS_R_FOREACH_A);
+
+ if ((error = dns_so_check(&R->so)))
+ goto error;
+
+ if (!dns_p_setptr(&F->answer, dns_so_fetch(&R->so, &error)))
+ goto error;
+
+ if (DNS_DEBUG) {
+ DNS_SHOW(F->answer, "ANSWER @ DEPTH: %u)", R->sp);
+ }
+
+ if (dns_p_rcode(F->answer) == DNS_RC_FORMERR ||
+ dns_p_rcode(F->answer) == DNS_RC_NOTIMP ||
+ dns_p_rcode(F->answer) == DNS_RC_BADVERS) {
+ /* Temporarily disable EDNS0 and try again. */
+ if (F->qflags & DNS_Q_EDNS0) {
+ F->qflags &= ~DNS_Q_EDNS0;
+ if ((error = dns_q_remake(&F->query, F->qflags)))
+ goto error;
+
+ dgoto(R->sp, DNS_R_FOREACH_A);
+ }
+ }
+
+ if ((error = dns_rr_parse(&rr, 12, F->query)))
+ goto error;
+
+ if (!(len = dns_d_expand(u.name, sizeof u.name, rr.dn.p, F->query, &error)))
+ goto error;
+ else if (len >= sizeof u.name)
+ goto toolong;
+
+ dns_rr_foreach(&rr, F->answer, .section = DNS_S_AN, .name = u.name, .type = rr.type) {
+ dgoto(R->sp, DNS_R_FINISH); /* Found */
+ }
+
+ dns_rr_foreach(&rr, F->answer, .section = DNS_S_AN, .name = u.name, .type = DNS_T_CNAME) {
+ F->ans_cname = rr;
+
+ dgoto(R->sp, DNS_R_CNAME0_A);
+ }
+
+ /*
+ * XXX: The condition here should probably check whether
+ * R->sp == 0, because DNS_R_SEARCH runs regardless of
+ * options.recurse. See DNS_R_BIND.
+ */
+ if (!R->resconf->options.recurse) {
+ /* Make first answer our tentative answer */
+ if (!R->nodata)
+ dns_p_movptr(&R->nodata, &F->answer);
+
+ dgoto(R->sp, DNS_R_SEARCH);
+ }
+
+ dns_rr_foreach(&rr, F->answer, .section = DNS_S_NS, .type = DNS_T_NS) {
+ dns_p_movptr(&F->hints, &F->answer);
+
+ dgoto(R->sp, DNS_R_ITERATE);
+ }
+
+ /* XXX: Should this go further up? */
+ if (dns_header(F->answer)->aa)
+ dgoto(R->sp, DNS_R_FINISH);
+
+ /* XXX: Should we copy F->answer to R->nodata? */
+
+ dgoto(R->sp, DNS_R_FOREACH_A);
+ case DNS_R_CNAME0_A:
+ if (&F[1] >= endof(R->stack))
+ dgoto(R->sp, DNS_R_FINISH);
+
+ if ((error = dns_cname_parse(&u.cname, &F->ans_cname, F->answer)))
+ goto error;
+ if ((error = dns_res_frame_prepare(R, &F[1], u.cname.host, dns_rr_type(12, F->query), DNS_C_IN)))
+ goto error;
+
+ F->state++;
+
+ dgoto(++R->sp, DNS_R_INIT);
+ case DNS_R_CNAME1_A:
+ if (!(P = dns_res_merge(F->answer, F[1].answer, &error)))
+ goto error;
+
+ dns_p_setptr(&F->answer, P);
+
+ dgoto(R->sp, DNS_R_FINISH);
+ case DNS_R_FINISH:
+ if (!F->answer)
+ goto noanswer;
+
+ if (!R->resconf->options.smart || R->sp > 0)
+ dgoto(R->sp, DNS_R_DONE);
+
+ R->smart.section = DNS_S_AN;
+ R->smart.type = R->qtype;
+
+ dns_rr_i_init(&R->smart, F->answer);
+
+ F->state++;
+ case DNS_R_SMART0_A:
+ if (&F[1] >= endof(R->stack))
+ dgoto(R->sp, DNS_R_DONE);
+
+ while (dns_rr_grep(&rr, 1, &R->smart, F->answer, &error)) {
+ union {
+ struct dns_ns ns;
+ struct dns_mx mx;
+ struct dns_srv srv;
+ } rd;
+ const char *qname;
+ enum dns_type qtype;
+ enum dns_class qclass;
+
+ switch (rr.type) {
+ case DNS_T_NS:
+ if ((error = dns_ns_parse(&rd.ns, &rr, F->answer)))
+ goto error;
+
+ qname = rd.ns.host;
+ qtype = DNS_T_A;
+ qclass = DNS_C_IN;
+
+ break;
+ case DNS_T_MX:
+ if ((error = dns_mx_parse(&rd.mx, &rr, F->answer)))
+ goto error;
+
+ qname = rd.mx.host;
+ qtype = DNS_T_A;
+ qclass = DNS_C_IN;
+
+ break;
+ case DNS_T_SRV:
+ if ((error = dns_srv_parse(&rd.srv, &rr, F->answer)))
+ goto error;
+
+ qname = rd.srv.target;
+ qtype = DNS_T_A;
+ qclass = DNS_C_IN;
+
+ break;
+ default:
+ continue;
+ } /* switch() */
+
+ if ((error = dns_res_frame_prepare(R, &F[1], qname, qtype, qclass)))
+ goto error;
+
+ F->state++;
+
+ dgoto(++R->sp, DNS_R_INIT);
+ } /* while() */
+
+ /*
+ * NOTE: SMTP specification says to fallback to A record.
+ *
+ * XXX: Should we add a mock MX answer?
+ */
+ if (R->qtype == DNS_T_MX && R->smart.state.count == 0) {
+ if ((error = dns_res_frame_prepare(R, &F[1], R->qname, DNS_T_A, DNS_C_IN)))
+ goto error;
+
+ R->smart.state.count++;
+ F->state++;
+
+ dgoto(++R->sp, DNS_R_INIT);
+ }
+
+ dgoto(R->sp, DNS_R_DONE);
+ case DNS_R_SMART1_A:
+ if (!F[1].answer)
+ goto noanswer;
+
+ /*
+ * FIXME: For CNAME chains (which are typically illegal in
+ * this context), we should rewrite the record host name
+ * to the original smart qname. All the user cares about
+ * is locating that A/AAAA record.
+ */
+ dns_rr_foreach(&rr, F[1].answer, .section = DNS_S_AN, .type = DNS_T_A) {
+ rr.section = DNS_S_AR;
+
+ if (dns_rr_exists(&rr, F[1].answer, F->answer))
+ continue;
+
+ while ((error = dns_rr_copy(F->answer, &rr, F[1].answer))) {
+ if (error != DNS_ENOBUFS)
+ goto error;
+ if ((error = dns_p_grow(&F->answer)))
+ goto error;
+ }
+ }
+
+ dgoto(R->sp, DNS_R_SMART0_A);
+ case DNS_R_DONE:
+ if (!F->answer)
+ goto noanswer;
+
+ if (R->sp > 0)
+ dgoto(--R->sp, F[-1].state);
+
+ break;
+ case DNS_R_SERVFAIL:
+ if (!dns_p_setptr(&F->answer, dns_p_make(DNS_P_QBUFSIZ, &error)))
+ goto error;
+
+ dns_header(F->answer)->qr = 1;
+ dns_header(F->answer)->rcode = DNS_RC_SERVFAIL;
+
+ if ((error = dns_p_push(F->answer, DNS_S_QD, R->qname, strlen(R->qname), R->qtype, R->qclass, 0, 0)))
+ goto error;
+
+ dgoto(R->sp, DNS_R_DONE);
+ default:
+ error = EINVAL;
+
+ goto error;
+ } /* switch () */
+
+ return 0;
+noquery:
+ error = DNS_ENOQUERY;
+
+ goto error;
+noanswer:
+ error = DNS_ENOANSWER;
+
+ goto error;
+toolong:
+ error = DNS_EILLEGAL;
+
+ /* FALL THROUGH */
+error:
+ return error;
+} /* dns_res_exec() */
+
+#undef goto
+
+
+void dns_res_clear(struct dns_resolver *R) {
+ switch (R->stack[R->sp].state) {
+ case DNS_R_CHECK:
+ R->cache->clear(R->cache);
+ break;
+ default:
+ dns_so_clear(&R->so);
+ break;
+ }
+} /* dns_res_clear() */
+
+
+static int dns_res_events2(struct dns_resolver *R, enum dns_events type) {
+ int events;
+
+ switch (R->stack[R->sp].state) {
+ case DNS_R_CHECK:
+ events = R->cache->events(R->cache);
+
+ return (type == DNS_LIBEVENT)? DNS_POLL2EV(events) : events;
+ default:
+ return dns_so_events2(&R->so, type);
+ }
+} /* dns_res_events2() */
+
+
+int dns_res_events(struct dns_resolver *R) {
+ return dns_res_events2(R, R->so.opts.events);
+} /* dns_res_events() */
+
+
+int dns_res_pollfd(struct dns_resolver *R) {
+ switch (R->stack[R->sp].state) {
+ case DNS_R_CHECK:
+ return R->cache->pollfd(R->cache);
+ default:
+ return dns_so_pollfd(&R->so);
+ }
+} /* dns_res_pollfd() */
+
+
+time_t dns_res_timeout(struct dns_resolver *R) {
+ time_t elapsed;
+
+ switch (R->stack[R->sp].state) {
+#if 0
+ case DNS_R_QUERY_AAAA:
+#endif
+ case DNS_R_QUERY_A:
+ elapsed = dns_so_elapsed(&R->so);
+
+ if (elapsed <= dns_resconf_timeout(R->resconf))
+ return R->resconf->options.timeout - elapsed;
+
+ break;
+ default:
+ break;
+ } /* switch() */
+
+ /*
+ * NOTE: We're not in a pollable state, or the user code hasn't
+ * called dns_res_check properly. The calling code is probably
+ * broken. Put them into a slow-burn pattern.
+ */
+ return 1;
+} /* dns_res_timeout() */
+
+
+time_t dns_res_elapsed(struct dns_resolver *R) {
+ return dns_elapsed(&R->elapsed);
+} /* dns_res_elapsed() */
+
+
+int dns_res_poll(struct dns_resolver *R, int timeout) {
+ return dns_poll(dns_res_pollfd(R), dns_res_events2(R, DNS_SYSPOLL), timeout);
+} /* dns_res_poll() */
+
+
+int dns_res_submit2(struct dns_resolver *R, const char *qname, size_t qlen, enum dns_type qtype, enum dns_class qclass) {
+ dns_res_reset(R);
+
+ /* Don't anchor; that can conflict with searchlist generation. */
+ dns_d_init(R->qname, sizeof R->qname, qname, (R->qlen = qlen), 0);
+
+ R->qtype = qtype;
+ R->qclass = qclass;
+
+ dns_begin(&R->elapsed);
+
+ dns_trace_res_submit(R->trace, R->qname, R->qtype, R->qclass, 0);
+
+ return 0;
+} /* dns_res_submit2() */
+
+
+int dns_res_submit(struct dns_resolver *R, const char *qname, enum dns_type qtype, enum dns_class qclass) {
+ return dns_res_submit2(R, qname, strlen(qname), qtype, qclass);
+} /* dns_res_submit() */
+
+
+int dns_res_check(struct dns_resolver *R) {
+ int error;
+
+ if (R->stack[0].state != DNS_R_DONE) {
+ if ((error = dns_res_exec(R)))
+ return error;
+ }
+
+ return 0;
+} /* dns_res_check() */
+
+
+struct dns_packet *dns_res_fetch(struct dns_resolver *R, int *_error) {
+ struct dns_packet *P = NULL;
+ int error;
+
+ if (R->stack[0].state != DNS_R_DONE) {
+ error = DNS_EUNKNOWN;
+ goto error;
+ }
+
+ if (!dns_p_movptr(&P, &R->stack[0].answer)) {
+ error = DNS_EFETCHED;
+ goto error;
+ }
+
+ dns_trace_res_fetch(R->trace, P, 0);
+
+ return P;
+error:
+ *_error = error;
+ dns_trace_res_fetch(R->trace, NULL, error);
+ return NULL;
+} /* dns_res_fetch() */
+
+
+static struct dns_packet *dns_res_fetch_and_study(struct dns_resolver *R, int *_error) {
+ struct dns_packet *P = NULL;
+ int error;
+
+ if (!(P = dns_res_fetch(R, &error)))
+ goto error;
+ if ((error = dns_p_study(P)))
+ goto error;
+
+ return P;
+error:
+ *_error = error;
+
+ dns_p_free(P);
+
+ return NULL;
+} /* dns_res_fetch_and_study() */
+
+
+struct dns_packet *dns_res_query(struct dns_resolver *res, const char *qname, enum dns_type qtype, enum dns_class qclass, int timeout, int *error_) {
+ int error;
+
+ if ((error = dns_res_submit(res, qname, qtype, qclass)))
+ goto error;
+
+ while ((error = dns_res_check(res))) {
+ if (dns_res_elapsed(res) > timeout)
+ error = DNS_ETIMEDOUT;
+
+ if (error != DNS_EAGAIN)
+ goto error;
+
+ if ((error = dns_res_poll(res, 1)))
+ goto error;
+ }
+
+ return dns_res_fetch(res, error_);
+error:
+ *error_ = error;
+
+ return 0;
+} /* dns_res_query() */
+
+
+const struct dns_stat *dns_res_stat(struct dns_resolver *res) {
+ return dns_so_stat(&res->so);
+} /* dns_res_stat() */
+
+
+void dns_res_sethints(struct dns_resolver *res, struct dns_hints *hints) {
+ dns_hints_acquire(hints); /* acquire first in case same hints object */
+ dns_hints_close(res->hints);
+ res->hints = hints;
+} /* dns_res_sethints() */
+
+
+struct dns_trace *dns_res_trace(struct dns_resolver *res) {
+ return res->trace;
+} /* dns_res_trace() */
+
+
+void dns_res_settrace(struct dns_resolver *res, struct dns_trace *trace) {
+ struct dns_trace *otrace = res->trace;
+ res->trace = dns_trace_acquire_p(trace);
+ dns_trace_close(otrace);
+ dns_so_settrace(&res->so, trace);
+} /* dns_res_settrace() */
+
+
+/*
+ * A D D R I N F O R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_addrinfo {
+ struct addrinfo hints;
+ struct dns_resolver *res;
+ struct dns_trace *trace;
+
+ char qname[DNS_D_MAXNAME + 1];
+ enum dns_type qtype;
+ unsigned short qport, port;
+
+ struct {
+ unsigned long todo;
+ int state;
+ int atype;
+ enum dns_type qtype;
+ } af;
+
+ struct dns_packet *answer;
+ struct dns_packet *glue;
+
+ struct dns_rr_i i, g;
+ struct dns_rr rr;
+
+ char cname[DNS_D_MAXNAME + 1];
+ char i_cname[DNS_D_MAXNAME + 1], g_cname[DNS_D_MAXNAME + 1];
+
+ int g_depth;
+
+ int state;
+ int found;
+
+ struct dns_stat st;
+}; /* struct dns_addrinfo */
+
+
+#define DNS_AI_AFMAX 32
+#define DNS_AI_AF2INDEX(af) (1UL << ((af) - 1))
+
+static inline unsigned long dns_ai_af2index(int af) {
+ dns_static_assert(dns_same_type(unsigned long, DNS_AI_AF2INDEX(1), 1), "internal type mismatch");
+ dns_static_assert(dns_same_type(unsigned long, ((struct dns_addrinfo *)0)->af.todo, 1), "internal type mismatch");
+
+ return (af > 0 && af <= DNS_AI_AFMAX)? DNS_AI_AF2INDEX(af) : 0;
+}
+
+static int dns_ai_setaf(struct dns_addrinfo *ai, int af, int qtype) {
+ ai->af.atype = af;
+ ai->af.qtype = qtype;
+
+ ai->af.todo &= ~dns_ai_af2index(af);
+
+ return af;
+} /* dns_ai_setaf() */
+
+#define DNS_SM_RESTORE \
+ do { pc = 0xff & (ai->af.state >> 0); i = 0xff & (ai->af.state >> 8); } while (0)
+#define DNS_SM_SAVE \
+ do { ai->af.state = ((0xff & pc) << 0) | ((0xff & i) << 8); } while (0)
+
+static int dns_ai_nextaf(struct dns_addrinfo *ai) {
+ int i, pc;
+
+ dns_static_assert(AF_UNSPEC == 0, "AF_UNSPEC constant not 0");
+ dns_static_assert(AF_INET <= DNS_AI_AFMAX, "AF_INET constant too large");
+ dns_static_assert(AF_INET6 <= DNS_AI_AFMAX, "AF_INET6 constant too large");
+
+ DNS_SM_ENTER;
+
+ if (ai->res) {
+ /*
+ * NB: On OpenBSD, at least, the types of entries resolved
+ * is the intersection of the /etc/resolv.conf families and
+ * the families permitted by the .ai_type hint. So if
+ * /etc/resolv.conf has "family inet4" and .ai_type
+ * is AF_INET6, then the address ::1 will return 0 entries
+ * even if AI_NUMERICHOST is specified in .ai_flags.
+ */
+ while (i < (int)lengthof(ai->res->resconf->family)) {
+ int af = ai->res->resconf->family[i++];
+
+ if (af == AF_UNSPEC) {
+ DNS_SM_EXIT;
+ } else if (af < 0 || af > DNS_AI_AFMAX) {
+ continue;
+ } else if (!(DNS_AI_AF2INDEX(af) & ai->af.todo)) {
+ continue;
+ } else if (af == AF_INET) {
+ DNS_SM_YIELD(dns_ai_setaf(ai, AF_INET, DNS_T_A));
+ } else if (af == AF_INET6) {
+ DNS_SM_YIELD(dns_ai_setaf(ai, AF_INET6, DNS_T_AAAA));
+ }
+ }
+ } else {
+ /*
+ * NB: If we get here than AI_NUMERICFLAGS should be set and
+ * order shouldn't matter.
+ */
+ if (DNS_AI_AF2INDEX(AF_INET) & ai->af.todo)
+ DNS_SM_YIELD(dns_ai_setaf(ai, AF_INET, DNS_T_A));
+ if (DNS_AI_AF2INDEX(AF_INET6) & ai->af.todo)
+ DNS_SM_YIELD(dns_ai_setaf(ai, AF_INET6, DNS_T_AAAA));
+ }
+
+ DNS_SM_LEAVE;
+
+ return dns_ai_setaf(ai, AF_UNSPEC, 0);
+} /* dns_ai_nextaf() */
+
+#undef DNS_SM_RESTORE
+#undef DNS_SM_SAVE
+
+static enum dns_type dns_ai_qtype(struct dns_addrinfo *ai) {
+ return (ai->qtype)? ai->qtype : ai->af.qtype;
+} /* dns_ai_qtype() */
+
+/* JW: This is not defined on mingw. */
+#ifndef AI_NUMERICSERV
+#define AI_NUMERICSERV 0
+#endif
+
+static dns_error_t dns_ai_parseport(unsigned short *port, const char *serv, const struct addrinfo *hints) {
+ const char *cp = serv;
+ unsigned long n = 0;
+
+ while (*cp >= '0' && *cp <= '9' && n < 65536) {
+ n *= 10;
+ n += *cp++ - '0';
+ }
+
+ if (*cp == '\0') {
+ if (cp == serv || n >= 65536)
+ return DNS_ESERVICE;
+
+ *port = n;
+
+ return 0;
+ }
+
+ if (hints->ai_flags & AI_NUMERICSERV)
+ return DNS_ESERVICE;
+
+ /* TODO: try getaddrinfo(NULL, serv, { .ai_flags = AI_NUMERICSERV }) */
+
+ return DNS_ESERVICE;
+} /* dns_ai_parseport() */
+
+
+struct dns_addrinfo *dns_ai_open(const char *host, const char *serv, enum dns_type qtype, const struct addrinfo *hints, struct dns_resolver *res, int *_error) {
+ static const struct dns_addrinfo ai_initializer;
+ struct dns_addrinfo *ai;
+ int error;
+
+ if (res) {
+ dns_res_acquire(res);
+ } else if (!(hints->ai_flags & AI_NUMERICHOST)) {
+ /*
+ * NOTE: it's assumed that *_error is set from a previous
+ * API function call, such as dns_res_stub(). Should change
+ * this semantic, but it's applied elsewhere, too.
+ */
+ if (!*_error)
+ *_error = EINVAL;
+ return NULL;
+ }
+
+ if (!(ai = malloc(sizeof *ai)))
+ goto syerr;
+
+ *ai = ai_initializer;
+ ai->hints = *hints;
+
+ ai->res = res;
+ res = NULL;
+
+ if (sizeof ai->qname <= dns_strlcpy(ai->qname, host, sizeof ai->qname))
+ { error = ENAMETOOLONG; goto error; }
+
+ ai->qtype = qtype;
+ ai->qport = 0;
+
+ if (serv && (error = dns_ai_parseport(&ai->qport, serv, hints)))
+ goto error;
+ ai->port = ai->qport;
+
+ /*
+ * FIXME: If an explicit A or AAAA record type conflicts with
+ * .ai_family or with resconf.family (i.e. AAAA specified but
+ * AF_INET6 not in interection of .ai_family and resconf.family),
+ * then what?
+ */
+ switch (ai->qtype) {
+ case DNS_T_A:
+ ai->af.todo = DNS_AI_AF2INDEX(AF_INET);
+ break;
+ case DNS_T_AAAA:
+ ai->af.todo = DNS_AI_AF2INDEX(AF_INET6);
+ break;
+ default: /* 0, MX, SRV, etc */
+ switch (ai->hints.ai_family) {
+ case AF_UNSPEC:
+ ai->af.todo = DNS_AI_AF2INDEX(AF_INET) | DNS_AI_AF2INDEX(AF_INET6);
+ break;
+ case AF_INET:
+ ai->af.todo = DNS_AI_AF2INDEX(AF_INET);
+ break;
+ case AF_INET6:
+ ai->af.todo = DNS_AI_AF2INDEX(AF_INET6);
+ break;
+ default:
+ break;
+ }
+ }
+
+ return ai;
+syerr:
+ error = dns_syerr();
+error:
+ *_error = error;
+
+ dns_ai_close(ai);
+ dns_res_close(res);
+
+ return NULL;
+} /* dns_ai_open() */
+
+
+void dns_ai_close(struct dns_addrinfo *ai) {
+ if (!ai)
+ return;
+
+ dns_res_close(ai->res);
+ dns_trace_close(ai->trace);
+
+ if (ai->answer != ai->glue)
+ dns_p_free(ai->glue);
+
+ dns_p_free(ai->answer);
+ free(ai);
+} /* dns_ai_close() */
+
+
+static int dns_ai_setent(struct addrinfo **ent, union dns_any *any, enum dns_type type, struct dns_addrinfo *ai) {
+ struct sockaddr *saddr;
+ struct sockaddr_in sin;
+ struct sockaddr_in6 sin6;
+ const char *cname;
+ size_t clen;
+
+ switch (type) {
+ case DNS_T_A:
+ saddr = memset(&sin, '\0', sizeof sin);
+
+ sin.sin_family = AF_INET;
+ sin.sin_port = htons(ai->port);
+
+ memcpy(&sin.sin_addr, any, sizeof sin.sin_addr);
+
+ break;
+ case DNS_T_AAAA:
+ saddr = memset(&sin6, '\0', sizeof sin6);
+
+ sin6.sin6_family = AF_INET6;
+ sin6.sin6_port = htons(ai->port);
+
+ memcpy(&sin6.sin6_addr, any, sizeof sin6.sin6_addr);
+
+ break;
+ default:
+ return EINVAL;
+ } /* switch() */
+
+ if (ai->hints.ai_flags & AI_CANONNAME) {
+ cname = (*ai->cname)? ai->cname : ai->qname;
+ clen = strlen(cname);
+ } else {
+ cname = NULL;
+ clen = 0;
+ }
+
+ if (!(*ent = malloc(sizeof **ent + dns_sa_len(saddr) + ((ai->hints.ai_flags & AI_CANONNAME)? clen + 1 : 0))))
+ return dns_syerr();
+
+ memset(*ent, '\0', sizeof **ent);
+
+ (*ent)->ai_family = saddr->sa_family;
+ (*ent)->ai_socktype = ai->hints.ai_socktype;
+ (*ent)->ai_protocol = ai->hints.ai_protocol;
+
+ (*ent)->ai_addr = memcpy((unsigned char *)*ent + sizeof **ent, saddr, dns_sa_len(saddr));
+ (*ent)->ai_addrlen = dns_sa_len(saddr);
+
+ if (ai->hints.ai_flags & AI_CANONNAME)
+ (*ent)->ai_canonname = memcpy((unsigned char *)*ent + sizeof **ent + dns_sa_len(saddr), cname, clen + 1);
+
+ ai->found++;
+
+ return 0;
+} /* dns_ai_setent() */
+
+
+enum dns_ai_state {
+ DNS_AI_S_INIT,
+ DNS_AI_S_NEXTAF,
+ DNS_AI_S_NUMERIC,
+ DNS_AI_S_SUBMIT,
+ DNS_AI_S_CHECK,
+ DNS_AI_S_FETCH,
+ DNS_AI_S_FOREACH_I,
+ DNS_AI_S_INIT_G,
+ DNS_AI_S_ITERATE_G,
+ DNS_AI_S_FOREACH_G,
+ DNS_AI_S_SUBMIT_G,
+ DNS_AI_S_CHECK_G,
+ DNS_AI_S_FETCH_G,
+ DNS_AI_S_DONE,
+}; /* enum dns_ai_state */
+
+#define dns_ai_goto(which) do { ai->state = (which); goto exec; } while (0)
+
+int dns_ai_nextent(struct addrinfo **ent, struct dns_addrinfo *ai) {
+ struct dns_packet *ans, *glue;
+ struct dns_rr rr;
+ char qname[DNS_D_MAXNAME + 1];
+ union dns_any any;
+ size_t qlen, clen;
+ int error;
+
+ *ent = 0;
+
+exec:
+
+ switch (ai->state) {
+ case DNS_AI_S_INIT:
+ ai->state++;
+ case DNS_AI_S_NEXTAF:
+ if (!dns_ai_nextaf(ai))
+ dns_ai_goto(DNS_AI_S_DONE);
+
+ ai->state++;
+ case DNS_AI_S_NUMERIC:
+ if (1 == dns_inet_pton(AF_INET, ai->qname, &any.a)) {
+ if (ai->af.atype == AF_INET) {
+ ai->state = DNS_AI_S_NEXTAF;
+ return dns_ai_setent(ent, &any, DNS_T_A, ai);
+ } else {
+ dns_ai_goto(DNS_AI_S_NEXTAF);
+ }
+ }
+
+ if (1 == dns_inet_pton(AF_INET6, ai->qname, &any.aaaa)) {
+ if (ai->af.atype == AF_INET6) {
+ ai->state = DNS_AI_S_NEXTAF;
+ return dns_ai_setent(ent, &any, DNS_T_AAAA, ai);
+ } else {
+ dns_ai_goto(DNS_AI_S_NEXTAF);
+ }
+ }
+
+ if (ai->hints.ai_flags & AI_NUMERICHOST)
+ dns_ai_goto(DNS_AI_S_NEXTAF);
+
+ ai->state++;
+ case DNS_AI_S_SUBMIT:
+ assert(ai->res);
+
+ if ((error = dns_res_submit(ai->res, ai->qname, dns_ai_qtype(ai), DNS_C_IN)))
+ return error;
+
+ ai->state++;
+ case DNS_AI_S_CHECK:
+ if ((error = dns_res_check(ai->res)))
+ return error;
+
+ ai->state++;
+ case DNS_AI_S_FETCH:
+ if (!(ans = dns_res_fetch_and_study(ai->res, &error)))
+ return error;
+ if (ai->glue != ai->answer)
+ dns_p_free(ai->glue);
+ ai->glue = dns_p_movptr(&ai->answer, &ans);
+
+ /* Search generator may have changed the qname. */
+ if (!(qlen = dns_d_expand(qname, sizeof qname, 12, ai->answer, &error)))
+ return error;
+ else if (qlen >= sizeof qname)
+ return DNS_EILLEGAL;
+ if (!dns_d_cname(ai->cname, sizeof ai->cname, qname, qlen, ai->answer, &error))
+ return error;
+
+ dns_strlcpy(ai->i_cname, ai->cname, sizeof ai->i_cname);
+ dns_rr_i_init(&ai->i, ai->answer);
+ ai->i.section = DNS_S_AN;
+ ai->i.name = ai->i_cname;
+ ai->i.type = dns_ai_qtype(ai);
+ ai->i.sort = &dns_rr_i_order;
+
+ ai->state++;
+ case DNS_AI_S_FOREACH_I:
+ if (!dns_rr_grep(&rr, 1, &ai->i, ai->answer, &error))
+ dns_ai_goto(DNS_AI_S_NEXTAF);
+
+ if ((error = dns_any_parse(&any, &rr, ai->answer)))
+ return error;
+
+ ai->port = ai->qport;
+
+ switch (rr.type) {
+ case DNS_T_A:
+ case DNS_T_AAAA:
+ return dns_ai_setent(ent, &any, rr.type, ai);
+ default:
+ if (!(clen = dns_any_cname(ai->cname, sizeof ai->cname, &any, rr.type)))
+ dns_ai_goto(DNS_AI_S_FOREACH_I);
+
+ /*
+ * Find the "real" canonical name. Some authorities
+ * publish aliases where an RFC defines a canonical
+ * name. We trust that the resolver followed any
+ * CNAME chains on it's own, regardless of whether
+ * the "smart" option is enabled.
+ */
+ if (!dns_d_cname(ai->cname, sizeof ai->cname, ai->cname, clen, ai->answer, &error))
+ return error;
+
+ if (rr.type == DNS_T_SRV)
+ ai->port = any.srv.port;
+
+ break;
+ } /* switch() */
+
+ ai->state++;
+ case DNS_AI_S_INIT_G:
+ ai->g_depth = 0;
+
+ ai->state++;
+ case DNS_AI_S_ITERATE_G:
+ dns_strlcpy(ai->g_cname, ai->cname, sizeof ai->g_cname);
+ dns_rr_i_init(&ai->g, ai->glue);
+ ai->g.section = DNS_S_ALL & ~DNS_S_QD;
+ ai->g.name = ai->g_cname;
+ ai->g.type = ai->af.qtype;
+
+ ai->state++;
+ case DNS_AI_S_FOREACH_G:
+ if (!dns_rr_grep(&rr, 1, &ai->g, ai->glue, &error)) {
+ if (dns_rr_i_count(&ai->g) > 0)
+ dns_ai_goto(DNS_AI_S_FOREACH_I);
+ else
+ dns_ai_goto(DNS_AI_S_SUBMIT_G);
+ }
+
+ if ((error = dns_any_parse(&any, &rr, ai->glue)))
+ return error;
+
+ return dns_ai_setent(ent, &any, rr.type, ai);
+ case DNS_AI_S_SUBMIT_G:
+ /* skip if already queried */
+ if (dns_rr_grep(&rr, 1, dns_rr_i_new(ai->glue, .section = DNS_S_QD, .name = ai->g.name, .type = ai->g.type), ai->glue, &error))
+ dns_ai_goto(DNS_AI_S_FOREACH_I);
+ /* skip if we recursed (CNAME chains should have been handled in the resolver) */
+ if (++ai->g_depth > 1)
+ dns_ai_goto(DNS_AI_S_FOREACH_I);
+
+ if ((error = dns_res_submit(ai->res, ai->g.name, ai->g.type, DNS_C_IN)))
+ return error;
+
+ ai->state++;
+ case DNS_AI_S_CHECK_G:
+ if ((error = dns_res_check(ai->res)))
+ return error;
+
+ ai->state++;
+ case DNS_AI_S_FETCH_G:
+ if (!(ans = dns_res_fetch_and_study(ai->res, &error)))
+ return error;
+
+ glue = dns_p_merge(ai->glue, DNS_S_ALL, ans, DNS_S_ALL, &error);
+ dns_p_setptr(&ans, NULL);
+ if (!glue)
+ return error;
+
+ if (ai->glue != ai->answer)
+ dns_p_free(ai->glue);
+ ai->glue = glue;
+
+ if (!dns_d_cname(ai->cname, sizeof ai->cname, ai->g.name, strlen(ai->g.name), ai->glue, &error))
+ dns_ai_goto(DNS_AI_S_FOREACH_I);
+
+ dns_ai_goto(DNS_AI_S_ITERATE_G);
+ case DNS_AI_S_DONE:
+ if (ai->found) {
+ return ENOENT; /* TODO: Just return 0 */
+ } else if (ai->answer) {
+ switch (dns_p_rcode(ai->answer)) {
+ case DNS_RC_NOERROR:
+ /* FALL THROUGH */
+ case DNS_RC_NXDOMAIN:
+ return DNS_ENONAME;
+ default:
+ return DNS_EFAIL;
+ }
+ } else {
+ return DNS_EFAIL;
+ }
+ default:
+ return EINVAL;
+ } /* switch() */
+} /* dns_ai_nextent() */
+
+
+time_t dns_ai_elapsed(struct dns_addrinfo *ai) {
+ return (ai->res)? dns_res_elapsed(ai->res) : 0;
+} /* dns_ai_elapsed() */
+
+
+void dns_ai_clear(struct dns_addrinfo *ai) {
+ if (ai->res)
+ dns_res_clear(ai->res);
+} /* dns_ai_clear() */
+
+
+int dns_ai_events(struct dns_addrinfo *ai) {
+ return (ai->res)? dns_res_events(ai->res) : 0;
+} /* dns_ai_events() */
+
+
+int dns_ai_pollfd(struct dns_addrinfo *ai) {
+ return (ai->res)? dns_res_pollfd(ai->res) : -1;
+} /* dns_ai_pollfd() */
+
+
+time_t dns_ai_timeout(struct dns_addrinfo *ai) {
+ return (ai->res)? dns_res_timeout(ai->res) : 0;
+} /* dns_ai_timeout() */
+
+
+int dns_ai_poll(struct dns_addrinfo *ai, int timeout) {
+ return (ai->res)? dns_res_poll(ai->res, timeout) : 0;
+} /* dns_ai_poll() */
+
+
+size_t dns_ai_print(void *_dst, size_t lim, struct addrinfo *ent, struct dns_addrinfo *ai) {
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+ char addr[DNS_PP_MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN) + 1];
+
+ dns_b_puts(&dst, "[ ");
+ dns_b_puts(&dst, ai->qname);
+ dns_b_puts(&dst, " IN ");
+ if (ai->qtype) {
+ dns_b_puts(&dst, dns_strtype(ai->qtype));
+ } else if (ent->ai_family == AF_INET) {
+ dns_b_puts(&dst, dns_strtype(DNS_T_A));
+ } else if (ent->ai_family == AF_INET6) {
+ dns_b_puts(&dst, dns_strtype(DNS_T_AAAA));
+ } else {
+ dns_b_puts(&dst, "0");
+ }
+ dns_b_puts(&dst, " ]\n");
+
+ dns_b_puts(&dst, ".ai_family = ");
+ switch (ent->ai_family) {
+ case AF_INET:
+ dns_b_puts(&dst, "AF_INET");
+ break;
+ case AF_INET6:
+ dns_b_puts(&dst, "AF_INET6");
+ break;
+ default:
+ dns_b_fmtju(&dst, ent->ai_family, 0);
+ break;
+ }
+ dns_b_putc(&dst, '\n');
+
+ dns_b_puts(&dst, ".ai_socktype = ");
+ switch (ent->ai_socktype) {
+ case SOCK_STREAM:
+ dns_b_puts(&dst, "SOCK_STREAM");
+ break;
+ case SOCK_DGRAM:
+ dns_b_puts(&dst, "SOCK_DGRAM");
+ break;
+ default:
+ dns_b_fmtju(&dst, ent->ai_socktype, 0);
+ break;
+ }
+ dns_b_putc(&dst, '\n');
+
+ dns_inet_ntop(dns_sa_family(ent->ai_addr), dns_sa_addr(dns_sa_family(ent->ai_addr), ent->ai_addr, NULL), addr, sizeof addr);
+ dns_b_puts(&dst, ".ai_addr = [");
+ dns_b_puts(&dst, addr);
+ dns_b_puts(&dst, "]:");
+ dns_b_fmtju(&dst, ntohs(*dns_sa_port(dns_sa_family(ent->ai_addr), ent->ai_addr)), 0);
+ dns_b_putc(&dst, '\n');
+
+ dns_b_puts(&dst, ".ai_canonname = ");
+ dns_b_puts(&dst, (ent->ai_canonname)? ent->ai_canonname : "[NULL]");
+ dns_b_putc(&dst, '\n');
+
+ return dns_b_strllen(&dst);
+} /* dns_ai_print() */
+
+
+const struct dns_stat *dns_ai_stat(struct dns_addrinfo *ai) {
+ return (ai->res)? dns_res_stat(ai->res) : &ai->st;
+} /* dns_ai_stat() */
+
+
+struct dns_trace *dns_ai_trace(struct dns_addrinfo *ai) {
+ return ai->trace;
+} /* dns_ai_trace() */
+
+
+void dns_ai_settrace(struct dns_addrinfo *ai, struct dns_trace *trace) {
+ struct dns_trace *otrace = ai->trace;
+ ai->trace = dns_trace_acquire_p(trace);
+ dns_trace_close(otrace);
+ if (ai->res)
+ dns_res_settrace(ai->res, trace);
+} /* dns_ai_settrace() */
+
+
+/*
+ * M I S C E L L A N E O U S R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+static const struct {
+ char name[16];
+ enum dns_section type;
+} dns_sections[] = {
+ { "QUESTION", DNS_S_QUESTION },
+ { "QD", DNS_S_QUESTION },
+ { "ANSWER", DNS_S_ANSWER },
+ { "AN", DNS_S_ANSWER },
+ { "AUTHORITY", DNS_S_AUTHORITY },
+ { "NS", DNS_S_AUTHORITY },
+ { "ADDITIONAL", DNS_S_ADDITIONAL },
+ { "AR", DNS_S_ADDITIONAL },
+};
+
+const char *(dns_strsection)(enum dns_section section, void *_dst, size_t lim) {
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+ unsigned i;
+
+ for (i = 0; i < lengthof(dns_sections); i++) {
+ if (dns_sections[i].type & section) {
+ dns_b_puts(&dst, dns_sections[i].name);
+ section &= ~dns_sections[i].type;
+ if (section)
+ dns_b_putc(&dst, '|');
+ }
+ }
+
+ if (section || dst.p == dst.base)
+ dns_b_fmtju(&dst, (0xffff & section), 0);
+
+ return dns_b_tostring(&dst);
+} /* dns_strsection() */
+
+
+enum dns_section dns_isection(const char *src) {
+ enum dns_section section = 0;
+ char sbuf[128];
+ char *name, *next;
+ unsigned i;
+
+ dns_strlcpy(sbuf, src, sizeof sbuf);
+ next = sbuf;
+
+ while ((name = dns_strsep(&next, "|+, \t"))) {
+ for (i = 0; i < lengthof(dns_sections); i++) {
+ if (!strcasecmp(dns_sections[i].name, name)) {
+ section |= dns_sections[i].type;
+ break;
+ }
+ }
+ }
+
+ return section;
+} /* dns_isection() */
+
+
+static const struct {
+ char name[8];
+ enum dns_class type;
+} dns_classes[] = {
+ { "IN", DNS_C_IN },
+};
+
+const char *(dns_strclass)(enum dns_class type, void *_dst, size_t lim) {
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+ unsigned i;
+
+ for (i = 0; i < lengthof(dns_classes); i++) {
+ if (dns_classes[i].type == type) {
+ dns_b_puts(&dst, dns_classes[i].name);
+ break;
+ }
+ }
+
+ if (dst.p == dst.base)
+ dns_b_fmtju(&dst, (0xffff & type), 0);
+
+ return dns_b_tostring(&dst);
+} /* dns_strclass() */
+
+
+enum dns_class dns_iclass(const char *name) {
+ unsigned i, class;
+
+ for (i = 0; i < lengthof(dns_classes); i++) {
+ if (!strcasecmp(dns_classes[i].name, name))
+ return dns_classes[i].type;
+ }
+
+ class = 0;
+ while (dns_isdigit(*name)) {
+ class *= 10;
+ class += *name++ - '0';
+ }
+
+ return DNS_PP_MIN(class, 0xffff);
+} /* dns_iclass() */
+
+
+const char *(dns_strtype)(enum dns_type type, void *_dst, size_t lim) {
+ struct dns_buf dst = DNS_B_INTO(_dst, lim);
+ unsigned i;
+
+ for (i = 0; i < lengthof(dns_rrtypes); i++) {
+ if (dns_rrtypes[i].type == type) {
+ dns_b_puts(&dst, dns_rrtypes[i].name);
+ break;
+ }
+ }
+
+ if (dst.p == dst.base)
+ dns_b_fmtju(&dst, (0xffff & type), 0);
+
+ return dns_b_tostring(&dst);
+} /* dns_strtype() */
+
+
+enum dns_type dns_itype(const char *name) {
+ unsigned i, type;
+
+ for (i = 0; i < lengthof(dns_rrtypes); i++) {
+ if (!strcasecmp(dns_rrtypes[i].name, name))
+ return dns_rrtypes[i].type;
+ }
+
+ type = 0;
+ while (dns_isdigit(*name)) {
+ type *= 10;
+ type += *name++ - '0';
+ }
+
+ return DNS_PP_MIN(type, 0xffff);
+} /* dns_itype() */
+
+
+static char dns_opcodes[16][16] = {
+ [DNS_OP_QUERY] = "QUERY",
+ [DNS_OP_IQUERY] = "IQUERY",
+ [DNS_OP_STATUS] = "STATUS",
+ [DNS_OP_NOTIFY] = "NOTIFY",
+ [DNS_OP_UPDATE] = "UPDATE",
+};
+
+static const char *dns__strcode(int code, volatile char *dst, size_t lim) {
+ char _tmp[48] = "";
+ struct dns_buf tmp;
+ size_t p;
+
+ assert(lim > 0);
+ dns_b_fmtju(dns_b_into(&tmp, _tmp, DNS_PP_MIN(sizeof _tmp, lim - 1)), code, 0);
+
+ /* copy downwards so first byte is copied last (see below) */
+ p = (size_t)(tmp.p - tmp.base);
+ dst[p] = '\0';
+ while (p--)
+ dst[p] = _tmp[p];
+
+ return (const char *)dst;
+}
+
+const char *dns_stropcode(enum dns_opcode opcode) {
+ opcode = (unsigned)opcode % lengthof(dns_opcodes);
+
+ if ('\0' == dns_opcodes[opcode][0])
+ return dns__strcode(opcode, dns_opcodes[opcode], sizeof dns_opcodes[opcode]);
+
+ return dns_opcodes[opcode];
+} /* dns_stropcode() */
+
+
+enum dns_opcode dns_iopcode(const char *name) {
+ unsigned opcode;
+
+ for (opcode = 0; opcode < lengthof(dns_opcodes); opcode++) {
+ if (!strcasecmp(name, dns_opcodes[opcode]))
+ return opcode;
+ }
+
+ opcode = 0;
+ while (dns_isdigit(*name)) {
+ opcode *= 10;
+ opcode += *name++ - '0';
+ }
+
+ return DNS_PP_MIN(opcode, 0x0f);
+} /* dns_iopcode() */
+
+
+static char dns_rcodes[32][16] = {
+ [DNS_RC_NOERROR] = "NOERROR",
+ [DNS_RC_FORMERR] = "FORMERR",
+ [DNS_RC_SERVFAIL] = "SERVFAIL",
+ [DNS_RC_NXDOMAIN] = "NXDOMAIN",
+ [DNS_RC_NOTIMP] = "NOTIMP",
+ [DNS_RC_REFUSED] = "REFUSED",
+ [DNS_RC_YXDOMAIN] = "YXDOMAIN",
+ [DNS_RC_YXRRSET] = "YXRRSET",
+ [DNS_RC_NXRRSET] = "NXRRSET",
+ [DNS_RC_NOTAUTH] = "NOTAUTH",
+ [DNS_RC_NOTZONE] = "NOTZONE",
+ /* EDNS(0) extended RCODEs ... */
+ [DNS_RC_BADVERS] = "BADVERS",
+};
+
+const char *dns_strrcode(enum dns_rcode rcode) {
+ rcode = (unsigned)rcode % lengthof(dns_rcodes);
+
+ if ('\0' == dns_rcodes[rcode][0])
+ return dns__strcode(rcode, dns_rcodes[rcode], sizeof dns_rcodes[rcode]);
+
+ return dns_rcodes[rcode];
+} /* dns_strrcode() */
+
+
+enum dns_rcode dns_ircode(const char *name) {
+ unsigned rcode;
+
+ for (rcode = 0; rcode < lengthof(dns_rcodes); rcode++) {
+ if (!strcasecmp(name, dns_rcodes[rcode]))
+ return rcode;
+ }
+
+ rcode = 0;
+ while (dns_isdigit(*name)) {
+ rcode *= 10;
+ rcode += *name++ - '0';
+ }
+
+ return DNS_PP_MIN(rcode, 0xfff);
+} /* dns_ircode() */
+
+
+
+/*
+ * C O M M A N D - L I N E / R E G R E S S I O N R O U T I N E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+#if DNS_MAIN
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <ctype.h>
+
+#if _WIN32
+#include <getopt.h>
+#endif
+
+#if !_WIN32
+#include <err.h>
+#endif
+
+
+struct {
+ struct {
+ const char *path[8];
+ unsigned count;
+ } resconf, nssconf, hosts, cache;
+
+ const char *qname;
+ enum dns_type qtype;
+
+ int (*sort)();
+
+ const char *trace;
+
+ int verbose;
+
+ struct {
+ struct dns_resolv_conf *resconf;
+ struct dns_hosts *hosts;
+ struct dns_trace *trace;
+ } memo;
+
+ struct sockaddr_storage socks_host;
+} MAIN = {
+ .sort = &dns_rr_i_packet,
+};
+
+
+static void hexdump(const unsigned char *src, size_t len, FILE *fp) {
+ struct dns_hxd_lines_i lines = { 0 };
+ char line[128];
+
+ while (dns_hxd_lines(line, sizeof line, src, len, &lines)) {
+ fputs(line, fp);
+ }
+} /* hexdump() */
+
+
+DNS_NORETURN static void panic(const char *fmt, ...) {
+ va_list ap;
+
+ va_start(ap, fmt);
+
+#if _WIN32
+ vfprintf(stderr, fmt, ap);
+
+ exit(EXIT_FAILURE);
+#else
+ verrx(EXIT_FAILURE, fmt, ap);
+#endif
+} /* panic() */
+
+#define panic_(fn, ln, fmt, ...) \
+ panic(fmt "%0s", (fn), (ln), __VA_ARGS__)
+#define panic(...) \
+ panic_(__func__, __LINE__, "(%s:%d) " __VA_ARGS__, "")
+
+
+static void *grow(unsigned char *p, size_t size) {
+ void *tmp;
+
+ if (!(tmp = realloc(p, size)))
+ panic("realloc(%"PRIuZ"): %s", size, dns_strerror(errno));
+
+ return tmp;
+} /* grow() */
+
+
+static size_t add(size_t a, size_t b) {
+ if (~a < b)
+ panic("%"PRIuZ" + %"PRIuZ": integer overflow", a, b);
+
+ return a + b;
+} /* add() */
+
+
+static size_t append(unsigned char **dst, size_t osize, const void *src, size_t len) {
+ size_t size = add(osize, len);
+
+ *dst = grow(*dst, size);
+ memcpy(*dst + osize, src, len);
+
+ return size;
+} /* append() */
+
+
+static size_t slurp(unsigned char **dst, size_t osize, FILE *fp, const char *path) {
+ size_t size = osize;
+ unsigned char buf[1024];
+ size_t count;
+
+ while ((count = fread(buf, 1, sizeof buf, fp)))
+ size = append(dst, size, buf, count);
+
+ if (ferror(fp))
+ panic("%s: %s", path, dns_strerror(errno));
+
+ return size;
+} /* slurp() */
+
+
+static struct dns_resolv_conf *resconf(void) {
+ struct dns_resolv_conf **resconf = &MAIN.memo.resconf;
+ const char *path;
+ unsigned i;
+ int error;
+
+ if (*resconf)
+ return *resconf;
+
+ if (!(*resconf = dns_resconf_open(&error)))
+ panic("dns_resconf_open: %s", dns_strerror(error));
+
+ if (!MAIN.resconf.count)
+ MAIN.resconf.path[MAIN.resconf.count++] = "/etc/resolv.conf";
+
+ for (i = 0; i < MAIN.resconf.count; i++) {
+ path = MAIN.resconf.path[i];
+
+ if (0 == strcmp(path, "-"))
+ error = dns_resconf_loadfile(*resconf, stdin);
+ else
+ error = dns_resconf_loadpath(*resconf, path);
+
+ if (error)
+ panic("%s: %s", path, dns_strerror(error));
+ }
+
+ for (i = 0; i < MAIN.nssconf.count; i++) {
+ path = MAIN.nssconf.path[i];
+
+ if (0 == strcmp(path, "-"))
+ error = dns_nssconf_loadfile(*resconf, stdin);
+ else
+ error = dns_nssconf_loadpath(*resconf, path);
+
+ if (error)
+ panic("%s: %s", path, dns_strerror(error));
+ }
+
+ if (!MAIN.nssconf.count) {
+ path = "/etc/nsswitch.conf";
+
+ if (!(error = dns_nssconf_loadpath(*resconf, path)))
+ MAIN.nssconf.path[MAIN.nssconf.count++] = path;
+ else if (error != ENOENT)
+ panic("%s: %s", path, dns_strerror(error));
+ }
+
+ return *resconf;
+} /* resconf() */
+
+
+static struct dns_hosts *hosts(void) {
+ struct dns_hosts **hosts = &MAIN.memo.hosts;
+ const char *path;
+ unsigned i;
+ int error;
+
+ if (*hosts)
+ return *hosts;
+
+ if (!MAIN.hosts.count) {
+ MAIN.hosts.path[MAIN.hosts.count++] = "/etc/hosts";
+
+ /* Explicitly test dns_hosts_local() */
+ if (!(*hosts = dns_hosts_local(&error)))
+ panic("%s: %s", "/etc/hosts", dns_strerror(error));
+
+ return *hosts;
+ }
+
+ if (!(*hosts = dns_hosts_open(&error)))
+ panic("dns_hosts_open: %s", dns_strerror(error));
+
+ for (i = 0; i < MAIN.hosts.count; i++) {
+ path = MAIN.hosts.path[i];
+
+ if (0 == strcmp(path, "-"))
+ error = dns_hosts_loadfile(*hosts, stdin);
+ else
+ error = dns_hosts_loadpath(*hosts, path);
+
+ if (error)
+ panic("%s: %s", path, dns_strerror(error));
+ }
+
+ return *hosts;
+} /* hosts() */
+
+
+#if DNS_CACHE
+#include "cache.h"
+
+static struct dns_cache *cache(void) {
+ static struct cache *cache;
+ const char *path;
+ unsigned i;
+ int error;
+
+ if (cache)
+ return cache_resi(cache);
+ if (!MAIN.cache.count)
+ return NULL;
+
+ if (!(cache = cache_open(&error)))
+ panic("%s: %s", MAIN.cache.path[0], dns_strerror(error));
+
+ for (i = 0; i < MAIN.cache.count; i++) {
+ path = MAIN.cache.path[i];
+
+ if (!strcmp(path, "-")) {
+ if ((error = cache_loadfile(cache, stdin, NULL, 0)))
+ panic("%s: %s", path, dns_strerror(error));
+ } else if ((error = cache_loadpath(cache, path, NULL, 0)))
+ panic("%s: %s", path, dns_strerror(error));
+ }
+
+ return cache_resi(cache);
+} /* cache() */
+#else
+static struct dns_cache *cache(void) { return NULL; }
+#endif
+
+
+static struct dns_trace *trace(const char *mode) {
+ static char omode[64] = "";
+ struct dns_trace **trace = &MAIN.memo.trace;
+ FILE *fp;
+ int error;
+
+ if (*trace && 0 == strcmp(omode, mode))
+ return *trace;
+ if (!MAIN.trace)
+ return NULL;
+
+ if (!(fp = fopen(MAIN.trace, mode)))
+ panic("%s: %s", MAIN.trace, strerror(errno));
+ dns_trace_close(*trace);
+ if (!(*trace = dns_trace_open(fp, &error)))
+ panic("%s: %s", MAIN.trace, dns_strerror(error));
+ dns_strlcpy(omode, mode, sizeof omode);
+
+ return *trace;
+}
+
+
+static void print_packet(struct dns_packet *P, FILE *fp) {
+ dns_p_dump3(P, dns_rr_i_new(P, .sort = MAIN.sort), fp);
+
+ if (MAIN.verbose > 2)
+ hexdump(P->data, P->end, fp);
+} /* print_packet() */
+
+
+static int parse_packet(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) {
+ struct dns_packet *P = dns_p_new(512);
+ struct dns_packet *Q = dns_p_new(512);
+ enum dns_section section;
+ struct dns_rr rr;
+ int error;
+ union dns_any any;
+ char pretty[sizeof any * 2];
+ size_t len;
+
+ P->end = fread(P->data, 1, P->size, stdin);
+
+ fputs(";; [HEADER]\n", stdout);
+ fprintf(stdout, ";; qr : %s(%d)\n", (dns_header(P)->qr)? "RESPONSE" : "QUERY", dns_header(P)->qr);
+ fprintf(stdout, ";; opcode : %s(%d)\n", dns_stropcode(dns_header(P)->opcode), dns_header(P)->opcode);
+ fprintf(stdout, ";; aa : %s(%d)\n", (dns_header(P)->aa)? "AUTHORITATIVE" : "NON-AUTHORITATIVE", dns_header(P)->aa);
+ fprintf(stdout, ";; tc : %s(%d)\n", (dns_header(P)->tc)? "TRUNCATED" : "NOT-TRUNCATED", dns_header(P)->tc);
+ fprintf(stdout, ";; rd : %s(%d)\n", (dns_header(P)->rd)? "RECURSION-DESIRED" : "RECURSION-NOT-DESIRED", dns_header(P)->rd);
+ fprintf(stdout, ";; ra : %s(%d)\n", (dns_header(P)->ra)? "RECURSION-ALLOWED" : "RECURSION-NOT-ALLOWED", dns_header(P)->ra);
+ fprintf(stdout, ";; rcode : %s(%d)\n", dns_strrcode(dns_p_rcode(P)), dns_p_rcode(P));
+
+ section = 0;
+
+ dns_rr_foreach(&rr, P, .sort = MAIN.sort) {
+ if (section != rr.section)
+ fprintf(stdout, "\n;; [%s:%d]\n", dns_strsection(rr.section), dns_p_count(P, rr.section));
+
+ if ((len = dns_rr_print(pretty, sizeof pretty, &rr, P, &error)))
+ fprintf(stdout, "%s\n", pretty);
+
+ dns_rr_copy(Q, &rr, P);
+
+ section = rr.section;
+ }
+
+ fputs("; ; ; ; ; ; ; ;\n\n", stdout);
+
+ section = 0;
+
+#if 0
+ dns_rr_foreach(&rr, Q, .name = "ns8.yahoo.com.") {
+#else
+ struct dns_rr rrset[32];
+ struct dns_rr_i *rri = dns_rr_i_new(Q, .name = dns_d_new("ns8.yahoo.com", DNS_D_ANCHOR), .sort = MAIN.sort);
+ unsigned rrcount = dns_rr_grep(rrset, lengthof(rrset), rri, Q, &error);
+
+ for (unsigned i = 0; i < rrcount; i++) {
+ rr = rrset[i];
+#endif
+ if (section != rr.section)
+ fprintf(stdout, "\n;; [%s:%d]\n", dns_strsection(rr.section), dns_p_count(Q, rr.section));
+
+ if ((len = dns_rr_print(pretty, sizeof pretty, &rr, Q, &error)))
+ fprintf(stdout, "%s\n", pretty);
+
+ section = rr.section;
+ }
+
+ if (MAIN.verbose > 1) {
+ fprintf(stderr, "orig:%"PRIuZ"\n", P->end);
+ hexdump(P->data, P->end, stdout);
+
+ fprintf(stderr, "copy:%"PRIuZ"\n", Q->end);
+ hexdump(Q->data, Q->end, stdout);
+ }
+
+ return 0;
+} /* parse_packet() */
+
+
+static int parse_domain(int argc, char *argv[]) {
+ char *dn;
+
+ dn = (argc > 1)? argv[1] : "f.l.google.com";
+
+ printf("[%s]\n", dn);
+
+ dn = dns_d_new(dn);
+
+ do {
+ puts(dn);
+ } while (dns_d_cleave(dn, strlen(dn) + 1, dn, strlen(dn)));
+
+ return 0;
+} /* parse_domain() */
+
+
+static int trim_domain(int argc, char **argv) {
+ for (argc--, argv++; argc > 0; argc--, argv++) {
+ char name[DNS_D_MAXNAME + 1];
+
+ dns_d_trim(name, sizeof name, *argv, strlen(*argv), DNS_D_ANCHOR);
+
+ puts(name);
+ }
+
+ return 0;
+} /* trim_domain() */
+
+
+static int expand_domain(int argc, char *argv[]) {
+ unsigned short rp = 0;
+ unsigned char *src = NULL;
+ unsigned char *dst;
+ struct dns_packet *pkt;
+ size_t lim = 0, len;
+ int error;
+
+ if (argc > 1)
+ rp = atoi(argv[1]);
+
+ len = slurp(&src, 0, stdin, "-");
+
+ if (!(pkt = dns_p_make(len, &error)))
+ panic("malloc(%"PRIuZ"): %s", len, dns_strerror(error));
+
+ memcpy(pkt->data, src, len);
+ pkt->end = len;
+
+ lim = 1;
+ dst = grow(NULL, lim);
+
+ while (lim <= (len = dns_d_expand(dst, lim, rp, pkt, &error))) {
+ lim = add(len, 1);
+ dst = grow(dst, lim);
+ }
+
+ if (!len)
+ panic("expand: %s", dns_strerror(error));
+
+ fwrite(dst, 1, len, stdout);
+ fflush(stdout);
+
+ free(src);
+ free(dst);
+ free(pkt);
+
+ return 0;
+} /* expand_domain() */
+
+
+static int show_resconf(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) {
+ unsigned i;
+
+ resconf(); /* load it */
+
+ fputs("; SOURCES\n", stdout);
+
+ for (i = 0; i < MAIN.resconf.count; i++)
+ fprintf(stdout, "; %s\n", MAIN.resconf.path[i]);
+
+ for (i = 0; i < MAIN.nssconf.count; i++)
+ fprintf(stdout, "; %s\n", MAIN.nssconf.path[i]);
+
+ fputs(";\n", stdout);
+
+ dns_resconf_dump(resconf(), stdout);
+
+ return 0;
+} /* show_resconf() */
+
+
+static int show_nssconf(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) {
+ unsigned i;
+
+ resconf();
+
+ fputs("# SOURCES\n", stdout);
+
+ for (i = 0; i < MAIN.resconf.count; i++)
+ fprintf(stdout, "# %s\n", MAIN.resconf.path[i]);
+
+ for (i = 0; i < MAIN.nssconf.count; i++)
+ fprintf(stdout, "# %s\n", MAIN.nssconf.path[i]);
+
+ fputs("#\n", stdout);
+
+ dns_nssconf_dump(resconf(), stdout);
+
+ return 0;
+} /* show_nssconf() */
+
+
+static int show_hosts(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) {
+ unsigned i;
+
+ hosts();
+
+ fputs("# SOURCES\n", stdout);
+
+ for (i = 0; i < MAIN.hosts.count; i++)
+ fprintf(stdout, "# %s\n", MAIN.hosts.path[i]);
+
+ fputs("#\n", stdout);
+
+ dns_hosts_dump(hosts(), stdout);
+
+ return 0;
+} /* show_hosts() */
+
+
+static int query_hosts(int argc, char *argv[]) {
+ struct dns_packet *Q = dns_p_new(512);
+ struct dns_packet *A;
+ char qname[DNS_D_MAXNAME + 1];
+ size_t qlen;
+ int error;
+
+ if (!MAIN.qname)
+ MAIN.qname = (argc > 1)? argv[1] : "localhost";
+ if (!MAIN.qtype)
+ MAIN.qtype = DNS_T_A;
+
+ hosts();
+
+ if (MAIN.qtype == DNS_T_PTR && !strstr(MAIN.qname, "arpa")) {
+ union { struct in_addr a; struct in6_addr a6; } addr;
+ int af = (strchr(MAIN.qname, ':'))? AF_INET6 : AF_INET;
+
+ if ((error = dns_pton(af, MAIN.qname, &addr)))
+ panic("%s: %s", MAIN.qname, dns_strerror(error));
+
+ qlen = dns_ptr_qname(qname, sizeof qname, af, &addr);
+ } else
+ qlen = dns_strlcpy(qname, MAIN.qname, sizeof qname);
+
+ if ((error = dns_p_push(Q, DNS_S_QD, qname, qlen, MAIN.qtype, DNS_C_IN, 0, 0)))
+ panic("%s: %s", qname, dns_strerror(error));
+
+ if (!(A = dns_hosts_query(hosts(), Q, &error)))
+ panic("%s: %s", qname, dns_strerror(error));
+
+ print_packet(A, stdout);
+
+ free(A);
+
+ return 0;
+} /* query_hosts() */
+
+
+static int search_list(int argc, char *argv[]) {
+ const char *qname = (argc > 1)? argv[1] : "f.l.google.com";
+ unsigned long i = 0;
+ char name[DNS_D_MAXNAME + 1];
+
+ printf("[%s]\n", qname);
+
+ while (dns_resconf_search(name, sizeof name, qname, strlen(qname), resconf(), &i))
+ puts(name);
+
+ return 0;
+} /* search_list() */
+
+
+static int permute_set(int argc, char *argv[]) {
+ unsigned lo, hi, i;
+ struct dns_k_permutor p;
+
+ hi = (--argc > 0)? atoi(argv[argc]) : 8;
+ lo = (--argc > 0)? atoi(argv[argc]) : 0;
+
+ fprintf(stderr, "[%u .. %u]\n", lo, hi);
+
+ dns_k_permutor_init(&p, lo, hi);
+
+ for (i = lo; i <= hi; i++)
+ fprintf(stdout, "%u\n", dns_k_permutor_step(&p));
+// printf("%u -> %u -> %u\n", i, dns_k_permutor_E(&p, i), dns_k_permutor_D(&p, dns_k_permutor_E(&p, i)));
+
+ return 0;
+} /* permute_set() */
+
+
+static int shuffle_16(int argc, char *argv[]) {
+ unsigned n, r;
+
+ if (--argc > 0) {
+ n = 0xffff & atoi(argv[argc]);
+ r = (--argc > 0)? (unsigned)atoi(argv[argc]) : dns_random();
+
+ fprintf(stdout, "%hu\n", dns_k_shuffle16(n, r));
+ } else {
+ r = dns_random();
+
+ for (n = 0; n < 65536; n++)
+ fprintf(stdout, "%hu\n", dns_k_shuffle16(n, r));
+ }
+
+ return 0;
+} /* shuffle_16() */
+
+
+static int dump_random(int argc, char *argv[]) {
+ unsigned char b[32];
+ unsigned i, j, n, r;
+
+ n = (argc > 1)? atoi(argv[1]) : 32;
+
+ while (n) {
+ i = 0;
+
+ do {
+ r = dns_random();
+
+ for (j = 0; j < sizeof r && i < n && i < sizeof b; i++, j++) {
+ b[i] = 0xff & r;
+ r >>= 8;
+ }
+ } while (i < n && i < sizeof b);
+
+ hexdump(b, i, stdout);
+
+ n -= i;
+ }
+
+ return 0;
+} /* dump_random() */
+
+
+static int send_query(int argc, char *argv[]) {
+ struct dns_packet *A, *Q = dns_p_new(512);
+ char host[INET6_ADDRSTRLEN + 1];
+ struct sockaddr_storage ss;
+ struct dns_socket *so;
+ int error, type;
+
+ if (argc > 1) {
+ ss.ss_family = (strchr(argv[1], ':'))? AF_INET6 : AF_INET;
+
+ if ((error = dns_pton(ss.ss_family, argv[1], dns_sa_addr(ss.ss_family, &ss, NULL))))
+ panic("%s: %s", argv[1], dns_strerror(error));
+
+ *dns_sa_port(ss.ss_family, &ss) = htons(53);
+ } else
+ memcpy(&ss, &resconf()->nameserver[0], dns_sa_len(&resconf()->nameserver[0]));
+
+ if (!dns_inet_ntop(ss.ss_family, dns_sa_addr(ss.ss_family, &ss, NULL), host, sizeof host))
+ panic("bad host address, or none provided");
+
+ if (!MAIN.qname)
+ MAIN.qname = "ipv6.google.com";
+ if (!MAIN.qtype)
+ MAIN.qtype = DNS_T_AAAA;
+
+ if ((error = dns_p_push(Q, DNS_S_QD, MAIN.qname, strlen(MAIN.qname), MAIN.qtype, DNS_C_IN, 0, 0)))
+ panic("dns_p_push: %s", dns_strerror(error));
+
+ dns_header(Q)->rd = 1;
+
+ if (strstr(argv[0], "udp"))
+ type = SOCK_DGRAM;
+ else if (strstr(argv[0], "tcp"))
+ type = SOCK_STREAM;
+ else
+ type = dns_res_tcp2type(resconf()->options.tcp);
+
+ fprintf(stderr, "querying %s for %s IN %s\n", host, MAIN.qname, dns_strtype(MAIN.qtype));
+
+ if (!(so = dns_so_open((struct sockaddr *)&resconf()->iface, type, dns_opts(), &error)))
+ panic("dns_so_open: %s", dns_strerror(error));
+
+ while (!(A = dns_so_query(so, Q, (struct sockaddr *)&ss, &error))) {
+ if (error != DNS_EAGAIN)
+ panic("dns_so_query: %s (%d)", dns_strerror(error), error);
+ if (dns_so_elapsed(so) > 10)
+ panic("query timed-out");
+
+ dns_so_poll(so, 1);
+ }
+
+ print_packet(A, stdout);
+
+ dns_so_close(so);
+
+ return 0;
+} /* send_query() */
+
+
+static int print_arpa(int argc, char *argv[]) {
+ const char *ip = (argc > 1)? argv[1] : "::1";
+ int af = (strchr(ip, ':'))? AF_INET6 : AF_INET;
+ union { struct in_addr a4; struct in6_addr a6; } addr;
+ char host[DNS_D_MAXNAME + 1];
+
+ if (1 != dns_inet_pton(af, ip, &addr) || 0 == dns_ptr_qname(host, sizeof host, af, &addr))
+ panic("%s: invalid address", ip);
+
+ fprintf(stdout, "%s\n", host);
+
+ return 0;
+} /* print_arpa() */
+
+
+static int show_hints(int argc, char *argv[]) {
+ struct dns_hints *(*load)(struct dns_resolv_conf *, int *);
+ const char *which, *how, *who;
+ struct dns_hints *hints;
+ int error;
+
+ which = (argc > 1)? argv[1] : "local";
+ how = (argc > 2)? argv[2] : "plain";
+ who = (argc > 3)? argv[3] : "google.com";
+
+ load = (0 == strcmp(which, "local"))
+ ? &dns_hints_local
+ : &dns_hints_root;
+
+ if (!(hints = load(resconf(), &error)))
+ panic("%s: %s", argv[0], dns_strerror(error));
+
+ if (0 == strcmp(how, "plain")) {
+ dns_hints_dump(hints, stdout);
+ } else {
+ struct dns_packet *query, *answer;
+
+ query = dns_p_new(512);
+
+ if ((error = dns_p_push(query, DNS_S_QUESTION, who, strlen(who), DNS_T_A, DNS_C_IN, 0, 0)))
+ panic("%s: %s", who, dns_strerror(error));
+
+ if (!(answer = dns_hints_query(hints, query, &error)))
+ panic("%s: %s", who, dns_strerror(error));
+
+ print_packet(answer, stdout);
+
+ free(answer);
+ }
+
+ dns_hints_close(hints);
+
+ return 0;
+} /* show_hints() */
+
+
+static int resolve_query(int argc DNS_NOTUSED, char *argv[]) {
+ _Bool recurse = !!strstr(argv[0], "recurse");
+ struct dns_hints *(*hints)() = (recurse)? &dns_hints_root : &dns_hints_local;
+ struct dns_resolver *R;
+ struct dns_packet *ans;
+ const struct dns_stat *st;
+ int error;
+
+ if (!MAIN.qname)
+ MAIN.qname = "www.google.com";
+ if (!MAIN.qtype)
+ MAIN.qtype = DNS_T_A;
+
+ resconf()->options.recurse = recurse;
+
+ if (!(R = dns_res_open(resconf(), hosts(), dns_hints_mortal(hints(resconf(), &error)), cache(),
+ dns_opts(.socks_host=&MAIN.socks_host), &error)))
+ panic("%s: %s", MAIN.qname, dns_strerror(error));
+
+ dns_res_settrace(R, trace("w+b"));
+
+ if ((error = dns_res_submit(R, MAIN.qname, MAIN.qtype, DNS_C_IN)))
+ panic("%s: %s", MAIN.qname, dns_strerror(error));
+
+ while ((error = dns_res_check(R))) {
+ if (error != DNS_EAGAIN)
+ panic("dns_res_check: %s (%d)", dns_strerror(error), error);
+ if (dns_res_elapsed(R) > 30)
+ panic("query timed-out");
+
+ dns_res_poll(R, 1);
+ }
+
+ ans = dns_res_fetch(R, &error);
+ print_packet(ans, stdout);
+ free(ans);
+
+ st = dns_res_stat(R);
+ putchar('\n');
+ printf(";; queries: %"PRIuZ"\n", st->queries);
+ printf(";; udp sent: %"PRIuZ" in %"PRIuZ" bytes\n", st->udp.sent.count, st->udp.sent.bytes);
+ printf(";; udp rcvd: %"PRIuZ" in %"PRIuZ" bytes\n", st->udp.rcvd.count, st->udp.rcvd.bytes);
+ printf(";; tcp sent: %"PRIuZ" in %"PRIuZ" bytes\n", st->tcp.sent.count, st->tcp.sent.bytes);
+ printf(";; tcp rcvd: %"PRIuZ" in %"PRIuZ" bytes\n", st->tcp.rcvd.count, st->tcp.rcvd.bytes);
+
+ dns_res_close(R);
+
+ return 0;
+} /* resolve_query() */
+
+
+static int resolve_addrinfo(int argc DNS_NOTUSED, char *argv[]) {
+ _Bool recurse = !!strstr(argv[0], "recurse");
+ struct dns_hints *(*hints)() = (recurse)? &dns_hints_root : &dns_hints_local;
+ struct dns_resolver *res = NULL;
+ struct dns_addrinfo *ai = NULL;
+ struct addrinfo ai_hints = { .ai_family = PF_UNSPEC, .ai_socktype = SOCK_STREAM, .ai_flags = AI_CANONNAME };
+ struct addrinfo *ent;
+ char pretty[512];
+ int error;
+
+ if (!MAIN.qname)
+ MAIN.qname = "www.google.com";
+ /* NB: MAIN.qtype of 0 means obey hints.ai_family */
+
+ resconf()->options.recurse = recurse;
+
+ if (!(res = dns_res_open(resconf(), hosts(), dns_hints_mortal(hints(resconf(), &error)), cache(), dns_opts(), &error)))
+ panic("%s: %s", MAIN.qname, dns_strerror(error));
+
+ if (!(ai = dns_ai_open(MAIN.qname, "80", MAIN.qtype, &ai_hints, res, &error)))
+ panic("%s: %s", MAIN.qname, dns_strerror(error));
+
+ dns_ai_settrace(ai, trace("w+b"));
+
+ do {
+ switch (error = dns_ai_nextent(&ent, ai)) {
+ case 0:
+ dns_ai_print(pretty, sizeof pretty, ent, ai);
+
+ fputs(pretty, stdout);
+
+ free(ent);
+
+ break;
+ case ENOENT:
+ break;
+ case DNS_EAGAIN:
+ if (dns_ai_elapsed(ai) > 30)
+ panic("query timed-out");
+
+ dns_ai_poll(ai, 1);
+
+ break;
+ default:
+ panic("dns_ai_nextent: %s (%d)", dns_strerror(error), error);
+ }
+ } while (error != ENOENT);
+
+ dns_res_close(res);
+ dns_ai_close(ai);
+
+ return 0;
+} /* resolve_addrinfo() */
+
+
+static int dump_trace(int argc DNS_NOTUSED, char *argv[]) {
+ int error;
+
+ if (!MAIN.trace)
+ panic("no trace file specified");
+
+ if ((error = dns_trace_dump(trace("r"), stdout)))
+ panic("dump_trace: %s", dns_strerror(error));
+
+ return 0;
+} /* dump_trace() */
+
+
+static int echo_port(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) {
+ union {
+ struct sockaddr sa;
+ struct sockaddr_in sin;
+ } port;
+ int fd;
+
+ memset(&port, 0, sizeof port);
+ port.sin.sin_family = AF_INET;
+ port.sin.sin_port = htons(5354);
+ port.sin.sin_addr.s_addr = inet_addr("127.0.0.1");
+
+ if (-1 == (fd = socket(PF_INET, SOCK_DGRAM, 0)))
+ panic("socket: %s", strerror(errno));
+
+ if (0 != bind(fd, &port.sa, sizeof port.sa))
+ panic("127.0.0.1:5353: %s", dns_strerror(errno));
+
+ for (;;) {
+ struct dns_packet *pkt = dns_p_new(512);
+ struct sockaddr_storage ss;
+ socklen_t slen = sizeof ss;
+ ssize_t count;
+#if defined(MSG_WAITALL) /* MinGW issue */
+ int rflags = MSG_WAITALL;
+#else
+ int rflags = 0;
+#endif
+
+ count = recvfrom(fd, (char *)pkt->data, pkt->size, rflags, (struct sockaddr *)&ss, &slen);
+
+ if (!count || count < 0)
+ panic("recvfrom: %s", strerror(errno));
+
+ pkt->end = count;
+
+ dns_p_dump(pkt, stdout);
+
+ (void)sendto(fd, (char *)pkt->data, pkt->end, 0, (struct sockaddr *)&ss, slen);
+ }
+
+ return 0;
+} /* echo_port() */
+
+
+static int isection(int argc, char *argv[]) {
+ const char *name = (argc > 1)? argv[1] : "";
+ int type;
+
+ type = dns_isection(name);
+ name = dns_strsection(type);
+
+ printf("%s (%d)\n", name, type);
+
+ return 0;
+} /* isection() */
+
+
+static int iclass(int argc, char *argv[]) {
+ const char *name = (argc > 1)? argv[1] : "";
+ int type;
+
+ type = dns_iclass(name);
+ name = dns_strclass(type);
+
+ printf("%s (%d)\n", name, type);
+
+ return 0;
+} /* iclass() */
+
+
+static int itype(int argc, char *argv[]) {
+ const char *name = (argc > 1)? argv[1] : "";
+ int type;
+
+ type = dns_itype(name);
+ name = dns_strtype(type);
+
+ printf("%s (%d)\n", name, type);
+
+ return 0;
+} /* itype() */
+
+
+static int iopcode(int argc, char *argv[]) {
+ const char *name = (argc > 1)? argv[1] : "";
+ int type;
+
+ type = dns_iopcode(name);
+ name = dns_stropcode(type);
+
+ printf("%s (%d)\n", name, type);
+
+ return 0;
+} /* iopcode() */
+
+
+static int ircode(int argc, char *argv[]) {
+ const char *name = (argc > 1)? argv[1] : "";
+ int type;
+
+ type = dns_ircode(name);
+ name = dns_strrcode(type);
+
+ printf("%s (%d)\n", name, type);
+
+ return 0;
+} /* ircode() */
+
+
+#define SIZE1(x) { DNS_PP_STRINGIFY(x), sizeof (x) }
+#define SIZE2(x, ...) SIZE1(x), SIZE1(__VA_ARGS__)
+#define SIZE3(x, ...) SIZE1(x), SIZE2(__VA_ARGS__)
+#define SIZE4(x, ...) SIZE1(x), SIZE3(__VA_ARGS__)
+#define SIZE(...) DNS_PP_CALL(DNS_PP_XPASTE(SIZE, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__)
+
+static int sizes(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) {
+ static const struct { const char *name; size_t size; } type[] = {
+ SIZE(struct dns_header, struct dns_packet, struct dns_rr, struct dns_rr_i),
+ SIZE(struct dns_a, struct dns_aaaa, struct dns_mx, struct dns_ns),
+ SIZE(struct dns_cname, struct dns_soa, struct dns_ptr, struct dns_srv),
+ SIZE(struct dns_sshfp, struct dns_txt, union dns_any),
+ SIZE(struct dns_resolv_conf, struct dns_hosts, struct dns_hints, struct dns_hints_i),
+ SIZE(struct dns_options, struct dns_socket, struct dns_resolver, struct dns_addrinfo),
+ SIZE(struct dns_cache), SIZE(size_t), SIZE(void *), SIZE(long)
+ };
+ unsigned i, max;
+
+ for (i = 0, max = 0; i < lengthof(type); i++)
+ max = DNS_PP_MAX(max, strlen(type[i].name));
+
+ for (i = 0; i < lengthof(type); i++)
+ printf("%*s : %"PRIuZ"\n", max, type[i].name, type[i].size);
+
+ return 0;
+} /* sizes() */
+
+
+static const struct { const char *cmd; int (*run)(); const char *help; } cmds[] = {
+ { "parse-packet", &parse_packet, "parse binary packet from stdin" },
+ { "parse-domain", &parse_domain, "anchor and iteratively cleave domain" },
+ { "trim-domain", &trim_domain, "trim and anchor domain name" },
+ { "expand-domain", &expand_domain, "expand domain at offset NN in packet from stdin" },
+ { "show-resconf", &show_resconf, "show resolv.conf data" },
+ { "show-hosts", &show_hosts, "show hosts data" },
+ { "show-nssconf", &show_nssconf, "show nsswitch.conf data" },
+ { "query-hosts", &query_hosts, "query A, AAAA or PTR in hosts data" },
+ { "search-list", &search_list, "generate query search list from domain" },
+ { "permute-set", &permute_set, "generate random permutation -> (0 .. N or N .. M)" },
+ { "shuffle-16", &shuffle_16, "simple 16-bit permutation" },
+ { "dump-random", &dump_random, "generate random bytes" },
+ { "send-query", &send_query, "send query to host" },
+ { "send-query-udp", &send_query, "send udp query to host" },
+ { "send-query-tcp", &send_query, "send tcp query to host" },
+ { "print-arpa", &print_arpa, "print arpa. zone name of address" },
+ { "show-hints", &show_hints, "print hints: show-hints [local|root] [plain|packet]" },
+ { "resolve-stub", &resolve_query, "resolve as stub resolver" },
+ { "resolve-recurse", &resolve_query, "resolve as recursive resolver" },
+ { "addrinfo-stub", &resolve_addrinfo, "resolve through getaddrinfo clone" },
+ { "addrinfo-recurse", &resolve_addrinfo, "resolve through getaddrinfo clone" },
+/* { "resolve-nameinfo", &resolve_query, "resolve as recursive resolver" }, */
+ { "dump-trace", &dump_trace, "dump the contents of a trace file" },
+ { "echo", &echo_port, "server echo mode, for nmap fuzzing" },
+ { "isection", &isection, "parse section string" },
+ { "iclass", &iclass, "parse class string" },
+ { "itype", &itype, "parse type string" },
+ { "iopcode", &iopcode, "parse opcode string" },
+ { "ircode", &ircode, "parse rcode string" },
+ { "sizes", &sizes, "print data structure sizes" },
+};
+
+
+static void print_usage(const char *progname, FILE *fp) {
+ static const char *usage =
+ " [OPTIONS] COMMAND [ARGS]\n"
+ " -c PATH Path to resolv.conf\n"
+ " -n PATH Path to nsswitch.conf\n"
+ " -l PATH Path to local hosts\n"
+ " -z PATH Path to zone cache\n"
+ " -q QNAME Query name\n"
+ " -t QTYPE Query type\n"
+ " -s HOW Sort records\n"
+ " -S ADDR Address of SOCKS server to use\n"
+ " -P PORT Port of SOCKS server to use\n"
+ " -f PATH Path to trace file\n"
+ " -v Be more verbose (-vv show packets; -vvv hexdump packets)\n"
+ " -V Print version info\n"
+ " -h Print this usage message\n"
+ "\n";
+ unsigned i, n, m;
+
+ fputs(progname, fp);
+ fputs(usage, fp);
+
+ for (i = 0, m = 0; i < lengthof(cmds); i++) {
+ if (strlen(cmds[i].cmd) > m)
+ m = strlen(cmds[i].cmd);
+ }
+
+ for (i = 0; i < lengthof(cmds); i++) {
+ fprintf(fp, " %s ", cmds[i].cmd);
+
+ for (n = strlen(cmds[i].cmd); n < m; n++)
+ putc(' ', fp);
+
+ fputs(cmds[i].help, fp);
+ putc('\n', fp);
+ }
+
+ fputs("\nReport bugs to William Ahern <william at 25thandClement.com>\n", fp);
+} /* print_usage() */
+
+
+static void print_version(const char *progname, FILE *fp) {
+ fprintf(fp, "%s (dns.c) %.8X\n", progname, dns_v_rel());
+ fprintf(fp, "vendor %s\n", dns_vendor());
+ fprintf(fp, "release %.8X\n", dns_v_rel());
+ fprintf(fp, "abi %.8X\n", dns_v_abi());
+ fprintf(fp, "api %.8X\n", dns_v_api());
+} /* print_version() */
+
+
+static void main_exit(void) {
+ dns_trace_close(MAIN.memo.trace);
+ MAIN.memo.trace = NULL;
+ dns_hosts_close(MAIN.memo.hosts);
+ MAIN.memo.hosts = NULL;
+ dns_resconf_close(MAIN.memo.resconf);
+ MAIN.memo.resconf = NULL;
+} /* main_exit() */
+
+int main(int argc, char **argv) {
+ extern int optind;
+ extern char *optarg;
+ const char *progname = argv[0];
+ unsigned i;
+ int ch;
+
+ atexit(&main_exit);
+
+ while (-1 != (ch = getopt(argc, argv, "q:t:c:n:l:z:s:S:P:f:vVh"))) {
+ switch (ch) {
+ case 'c':
+ assert(MAIN.resconf.count < lengthof(MAIN.resconf.path));
+
+ MAIN.resconf.path[MAIN.resconf.count++] = optarg;
+
+ break;
+ case 'n':
+ assert(MAIN.nssconf.count < lengthof(MAIN.nssconf.path));
+
+ MAIN.nssconf.path[MAIN.nssconf.count++] = optarg;
+
+ break;
+ case 'l':
+ assert(MAIN.hosts.count < lengthof(MAIN.hosts.path));
+
+ MAIN.hosts.path[MAIN.hosts.count++] = optarg;
+
+ break;
+ case 'z':
+ assert(MAIN.cache.count < lengthof(MAIN.cache.path));
+
+ MAIN.cache.path[MAIN.cache.count++] = optarg;
+
+ break;
+ case 'q':
+ MAIN.qname = optarg;
+
+ break;
+ case 't':
+ for (i = 0; i < lengthof(dns_rrtypes); i++) {
+ if (0 == strcasecmp(dns_rrtypes[i].name, optarg))
+ { MAIN.qtype = dns_rrtypes[i].type; break; }
+ }
+
+ if (MAIN.qtype)
+ break;
+
+ for (i = 0; dns_isdigit(optarg[i]); i++) {
+ MAIN.qtype *= 10;
+ MAIN.qtype += optarg[i] - '0';
+ }
+
+ if (!MAIN.qtype)
+ panic("%s: invalid query type", optarg);
+
+ break;
+ case 's':
+ if (0 == strcasecmp(optarg, "packet"))
+ MAIN.sort = &dns_rr_i_packet;
+ else if (0 == strcasecmp(optarg, "shuffle"))
+ MAIN.sort = &dns_rr_i_shuffle;
+ else if (0 == strcasecmp(optarg, "order"))
+ MAIN.sort = &dns_rr_i_order;
+ else
+ panic("%s: invalid sort method", optarg);
+
+ break;
+ case 'S': {
+ dns_error_t error;
+ struct dns_resolv_conf *conf = resconf();
+ conf->options.tcp = DNS_RESCONF_TCP_SOCKS;
+
+ MAIN.socks_host.ss_family = (strchr(optarg, ':')) ? AF_INET6 : AF_INET;
+ if ((error = dns_pton(MAIN.socks_host.ss_family, optarg,
+ dns_sa_addr(MAIN.socks_host.ss_family,
+ &MAIN.socks_host, NULL))))
+ panic("%s: %s", optarg, dns_strerror(error));
+
+ *dns_sa_port(MAIN.socks_host.ss_family, &MAIN.socks_host) = htons(1080);
+
+ break;
+ }
+ case 'P':
+ if (! MAIN.socks_host.ss_family)
+ panic("-P without prior -S");
+ *dns_sa_port(MAIN.socks_host.ss_family, &MAIN.socks_host) = htons(atoi(optarg));
+
+ break;
+ case 'f':
+ MAIN.trace = optarg;
+
+ break;
+ case 'v':
+ dns_debug = ++MAIN.verbose;
+
+ break;
+ case 'V':
+ print_version(progname, stdout);
+
+ return 0;
+ case 'h':
+ print_usage(progname, stdout);
+
+ return 0;
+ default:
+ print_usage(progname, stderr);
+
+ return EXIT_FAILURE;
+ } /* switch() */
+ } /* while() */
+
+ argc -= optind;
+ argv += optind;
+
+ for (i = 0; i < lengthof(cmds) && argv[0]; i++) {
+ if (0 == strcmp(cmds[i].cmd, argv[0]))
+ return cmds[i].run(argc, argv);
+ }
+
+ print_usage(progname, stderr);
+
+ return EXIT_FAILURE;
+} /* main() */
+
+
+#endif /* DNS_MAIN */
+
+
+/*
+ * pop file-scoped compiler annotations
+ */
+#if __clang__
+#pragma clang diagnostic pop
+#elif DNS_GNUC_PREREQ(4,6,0)
+#pragma GCC diagnostic pop
+#endif
diff --git a/dirmngr/dns.h b/dirmngr/dns.h
new file mode 100644
index 0000000..65911bc
--- /dev/null
+++ b/dirmngr/dns.h
@@ -0,0 +1,1361 @@
+/* ==========================================================================
+ * dns.h - Recursive, Reentrant DNS Resolver.
+ * --------------------------------------------------------------------------
+ * Copyright (c) 2009, 2010, 2012-2015 William Ahern
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to permit
+ * persons to whom the Software is furnished to do so, subject to the
+ * following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+ * NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * ==========================================================================
+ */
+#ifndef DNS_H
+#define DNS_H
+
+#include <stddef.h> /* size_t offsetof() */
+#include <stdint.h> /* uint64_t */
+#include <stdio.h> /* FILE */
+#include <string.h> /* strlen(3) */
+#include <time.h> /* struct timespec time_t */
+
+#if _WIN32
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#else
+#include <sys/param.h> /* BYTE_ORDER BIG_ENDIAN _BIG_ENDIAN */
+#include <sys/types.h> /* socklen_t */
+#include <sys/socket.h> /* struct socket */
+#include <poll.h> /* POLLIN POLLOUT */
+#include <netinet/in.h> /* struct in_addr struct in6_addr */
+#include <netdb.h> /* struct addrinfo */
+#endif
+
+
+/*
+ * V I S I B I L I T Y
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#ifndef DNS_PUBLIC
+#define DNS_PUBLIC
+#endif
+
+
+/*
+ * V E R S I O N
+ *
+ * Vendor: Entity for which versions numbers are relevant. (If forking
+ * change DNS_VENDOR to avoid confusion.)
+ *
+ * Three versions:
+ *
+ * REL Official "release"--bug fixes, new features, etc.
+ * ABI Changes to existing object sizes or parameter types
+ * API Changes that might effect application source.
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_VENDOR "william at 25thandClement.com"
+
+#define DNS_V_REL 0x20160809
+#define DNS_V_ABI 0x20160608
+#define DNS_V_API 0x20160809
+
+
+DNS_PUBLIC const char *dns_vendor(void);
+
+DNS_PUBLIC int dns_v_rel(void);
+DNS_PUBLIC int dns_v_abi(void);
+DNS_PUBLIC int dns_v_api(void);
+
+
+/*
+ * E R R O R S
+ *
+ * Errors and exceptions are always returned through an int. This should
+ * hopefully make integration easier in the majority of circumstances, and
+ * also cut down on useless compiler warnings.
+ *
+ * System and library errors are returned together. POSIX guarantees that
+ * all system errors are positive integers. Library errors are always
+ * negative integers in the range DNS_EBASE to DNS_ELAST, with the high bits
+ * set to the three magic ASCII characters "dns".
+ *
+ * dns_strerror() returns static English string descriptions of all known
+ * errors, and punts the remainder to strerror(3).
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_EBASE -(('d' << 24) | ('n' << 16) | ('s' << 8) | 64)
+
+#define dns_error_t int /* for documentation only */
+
+enum dns_errno {
+ DNS_ENOBUFS = DNS_EBASE,
+ DNS_EILLEGAL,
+ DNS_EORDER,
+ DNS_ESECTION,
+ DNS_EUNKNOWN,
+ DNS_EADDRESS,
+ DNS_ENOQUERY,
+ DNS_ENOANSWER,
+ DNS_EFETCHED,
+ DNS_ESERVICE, /* EAI_SERVICE */
+ DNS_ENONAME, /* EAI_NONAME */
+ DNS_EFAIL, /* EAI_FAIL */
+ DNS_ECONNFIN,
+ DNS_EVERIFY,
+ DNS_ELAST,
+}; /* dns_errno */
+
+DNS_PUBLIC const char *dns_strerror(dns_error_t);
+
+DNS_PUBLIC int *dns_debug_p(void);
+
+#define dns_debug (*dns_debug_p()) /* was extern int dns_debug before 20160523 API */
+
+
+/*
+ * C O M P I L E R A N N O T A T I O N S
+ *
+ * GCC with -Wextra, and clang by default, complain about overrides in
+ * initializer lists. Overriding previous member initializers is well
+ * defined behavior in C. dns.c relies on this behavior to define default,
+ * overrideable member values when instantiating configuration objects.
+ *
+ * dns_quietinit() guards a compound literal expression with pragmas to
+ * silence these shrill warnings. This alleviates the burden of requiring
+ * third-party projects to adjust their compiler flags.
+ *
+ * NOTE: If you take the address of the compound literal, take the address
+ * of the transformed expression, otherwise the compound literal lifetime is
+ * tied to the scope of the GCC statement expression.
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#if defined __clang__
+#define DNS_PRAGMA_PUSH _Pragma("clang diagnostic push")
+#define DNS_PRAGMA_QUIET _Pragma("clang diagnostic ignored \"-Winitializer-overrides\"")
+#define DNS_PRAGMA_POP _Pragma("clang diagnostic pop")
+
+#define dns_quietinit(...) \
+ DNS_PRAGMA_PUSH DNS_PRAGMA_QUIET __VA_ARGS__ DNS_PRAGMA_POP
+#elif (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) || __GNUC__ > 4
+#define DNS_PRAGMA_PUSH _Pragma("GCC diagnostic push")
+#define DNS_PRAGMA_QUIET _Pragma("GCC diagnostic ignored \"-Woverride-init\"")
+#define DNS_PRAGMA_POP _Pragma("GCC diagnostic pop")
+
+/* GCC parses the _Pragma operator less elegantly than clang. */
+#define dns_quietinit(...) \
+ __extension__ ({ DNS_PRAGMA_PUSH DNS_PRAGMA_QUIET __VA_ARGS__; DNS_PRAGMA_POP })
+#else
+#define DNS_PRAGMA_PUSH
+#define DNS_PRAGMA_QUIET
+#define DNS_PRAGMA_POP
+#define dns_quietinit(...) __VA_ARGS__
+#endif
+
+#if defined __GNUC__
+#define DNS_PRAGMA_EXTENSION __extension__
+#else
+#define DNS_PRAGMA_EXTENSION
+#endif
+
+
+/*
+ * E V E N T S I N T E R F A C E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#if defined(POLLIN)
+#define DNS_POLLIN POLLIN
+#else
+#define DNS_POLLIN 1
+#endif
+
+#if defined(POLLOUT)
+#define DNS_POLLOUT POLLOUT
+#else
+#define DNS_POLLOUT 2
+#endif
+
+
+/*
+ * See Application Interface below for configuring libevent bitmasks instead
+ * of poll(2) bitmasks.
+ */
+#define DNS_EVREAD 2
+#define DNS_EVWRITE 4
+
+
+#define DNS_POLL2EV(set) \
+ (((set) & DNS_POLLIN)? DNS_EVREAD : 0) | (((set) & DNS_POLLOUT)? DNS_EVWRITE : 0)
+
+#define DNS_EV2POLL(set) \
+ (((set) & DNS_EVREAD)? DNS_POLLIN : 0) | (((set) & DNS_EVWRITE)? DNS_POLLOUT : 0)
+
+
+/*
+ * E N U M E R A T I O N I N T E R F A C E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+enum dns_section {
+ DNS_S_QD = 0x01,
+#define DNS_S_QUESTION DNS_S_QD
+
+ DNS_S_AN = 0x02,
+#define DNS_S_ANSWER DNS_S_AN
+
+ DNS_S_NS = 0x04,
+#define DNS_S_AUTHORITY DNS_S_NS
+
+ DNS_S_AR = 0x08,
+#define DNS_S_ADDITIONAL DNS_S_AR
+
+ DNS_S_ALL = 0x0f
+}; /* enum dns_section */
+
+
+enum dns_class {
+ DNS_C_IN = 1,
+
+ DNS_C_ANY = 255
+}; /* enum dns_class */
+
+
+enum dns_type {
+ DNS_T_A = 1,
+ DNS_T_NS = 2,
+ DNS_T_CNAME = 5,
+ DNS_T_SOA = 6,
+ DNS_T_PTR = 12,
+ DNS_T_MX = 15,
+ DNS_T_TXT = 16,
+ DNS_T_AAAA = 28,
+ DNS_T_SRV = 33,
+ DNS_T_OPT = 41,
+ DNS_T_SSHFP = 44,
+ DNS_T_SPF = 99,
+ DNS_T_AXFR = 252,
+
+ DNS_T_ALL = 255
+}; /* enum dns_type */
+
+
+enum dns_opcode {
+ DNS_OP_QUERY = 0,
+ DNS_OP_IQUERY = 1,
+ DNS_OP_STATUS = 2,
+ DNS_OP_NOTIFY = 4,
+ DNS_OP_UPDATE = 5,
+}; /* dns_opcode */
+
+
+enum dns_rcode {
+ DNS_RC_NOERROR = 0,
+ DNS_RC_FORMERR = 1,
+ DNS_RC_SERVFAIL = 2,
+ DNS_RC_NXDOMAIN = 3,
+ DNS_RC_NOTIMP = 4,
+ DNS_RC_REFUSED = 5,
+ DNS_RC_YXDOMAIN = 6,
+ DNS_RC_YXRRSET = 7,
+ DNS_RC_NXRRSET = 8,
+ DNS_RC_NOTAUTH = 9,
+ DNS_RC_NOTZONE = 10,
+
+ /* EDNS(0) extended RCODEs */
+ DNS_RC_BADVERS = 16,
+}; /* dns_rcode */
+
+
+/*
+ * NOTE: These string functions need a small buffer in case the literal
+ * integer value needs to be printed and returned. UNLESS this buffer is
+ * SPECIFIED, the returned string has ONLY BLOCK SCOPE.
+ */
+#define DNS_STRMAXLEN 47 /* "QUESTION|ANSWER|AUTHORITY|ADDITIONAL" */
+
+DNS_PUBLIC const char *dns_strsection(enum dns_section, void *, size_t);
+#define dns_strsection3(a, b, c) \
+ dns_strsection((a), (b), (c))
+#define dns_strsection1(a) dns_strsection((a), (char [DNS_STRMAXLEN + 1]){ 0 }, DNS_STRMAXLEN + 1)
+#define dns_strsection(...) DNS_PP_CALL(DNS_PP_XPASTE(dns_strsection, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__)
+
+DNS_PUBLIC enum dns_section dns_isection(const char *);
+
+DNS_PUBLIC const char *dns_strclass(enum dns_class, void *, size_t);
+#define dns_strclass3(a, b, c) dns_strclass((a), (b), (c))
+#define dns_strclass1(a) dns_strclass((a), (char [DNS_STRMAXLEN + 1]){ 0 }, DNS_STRMAXLEN + 1)
+#define dns_strclass(...) DNS_PP_CALL(DNS_PP_XPASTE(dns_strclass, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__)
+
+DNS_PUBLIC enum dns_class dns_iclass(const char *);
+
+DNS_PUBLIC const char *dns_strtype(enum dns_type, void *, size_t);
+#define dns_strtype3(a, b, c) dns_strtype((a), (b), (c))
+#define dns_strtype1(a) dns_strtype((a), (char [DNS_STRMAXLEN + 1]){ 0 }, DNS_STRMAXLEN + 1)
+#define dns_strtype(...) DNS_PP_CALL(DNS_PP_XPASTE(dns_strtype, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__)
+
+DNS_PUBLIC enum dns_type dns_itype(const char *);
+
+DNS_PUBLIC const char *dns_stropcode(enum dns_opcode);
+
+DNS_PUBLIC enum dns_opcode dns_iopcode(const char *);
+
+DNS_PUBLIC const char *dns_strrcode(enum dns_rcode);
+
+DNS_PUBLIC enum dns_rcode dns_ircode(const char *);
+
+
+/*
+ * A T O M I C I N T E R F A C E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+typedef unsigned long dns_atomic_t;
+
+typedef unsigned long dns_refcount_t; /* must be same value type as dns_atomic_t */
+
+
+/*
+ * C R Y P T O I N T E R F A C E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+typedef unsigned dns_random_f(void);
+
+DNS_PUBLIC dns_random_f **dns_random_p(void);
+
+#define dns_random (*dns_random_p()) /* was extern unsigned (*dns_random)(void) before 20160523 API */
+
+
+/*
+ * P A C K E T I N T E R F A C E
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_header {
+ unsigned qid:16;
+
+#if (defined BYTE_ORDER && BYTE_ORDER == BIG_ENDIAN) || (defined __sun && defined _BIG_ENDIAN)
+ unsigned qr:1;
+ unsigned opcode:4;
+ unsigned aa:1;
+ unsigned tc:1;
+ unsigned rd:1;
+
+ unsigned ra:1;
+ unsigned unused:3;
+ unsigned rcode:4;
+#else
+ unsigned rd:1;
+ unsigned tc:1;
+ unsigned aa:1;
+ unsigned opcode:4;
+ unsigned qr:1;
+
+ unsigned rcode:4;
+ unsigned unused:3;
+ unsigned ra:1;
+#endif
+
+ unsigned qdcount:16;
+ unsigned ancount:16;
+ unsigned nscount:16;
+ unsigned arcount:16;
+}; /* struct dns_header */
+
+#define dns_header(p) (&(p)->header)
+
+
+#ifndef DNS_P_QBUFSIZ
+#define DNS_P_QBUFSIZ dns_p_calcsize(256 + 4)
+#endif
+
+#ifndef DNS_P_DICTSIZE
+#define DNS_P_DICTSIZE 16
+#endif
+
+struct dns_packet {
+ unsigned short dict[DNS_P_DICTSIZE];
+
+ struct dns_p_memo {
+ struct dns_s_memo {
+ unsigned short base, end;
+ } qd, an, ns, ar;
+
+ struct {
+ unsigned short p;
+ unsigned short maxudp;
+ unsigned ttl;
+ } opt;
+ } memo;
+
+ struct { struct dns_packet *cqe_next, *cqe_prev; } cqe;
+
+ size_t size, end;
+
+ int:16; /* tcp padding */
+
+ DNS_PRAGMA_EXTENSION union {
+ struct dns_header header;
+ unsigned char data[1];
+ };
+}; /* struct dns_packet */
+
+#define dns_p_calcsize(n) (offsetof(struct dns_packet, data) + DNS_PP_MAX(12, (n)))
+
+#define dns_p_sizeof(P) dns_p_calcsize((P)->end)
+
+/** takes size of maximum desired payload */
+#define dns_p_new(n) (dns_p_init((struct dns_packet *)&(union { unsigned char b[dns_p_calcsize((n))]; struct dns_packet p; }){ { 0 } }, dns_p_calcsize((n))))
+
+/** takes size of entire packet structure as allocated */
+DNS_PUBLIC struct dns_packet *dns_p_init(struct dns_packet *, size_t);
+
+/** takes size of maximum desired payload */
+DNS_PUBLIC struct dns_packet *dns_p_make(size_t, int *);
+
+DNS_PUBLIC int dns_p_grow(struct dns_packet **);
+
+DNS_PUBLIC struct dns_packet *dns_p_copy(struct dns_packet *, const struct dns_packet *);
+
+#define dns_p_opcode(P) (dns_header(P)->opcode)
+
+DNS_PUBLIC enum dns_rcode dns_p_rcode(struct dns_packet *);
+
+DNS_PUBLIC unsigned dns_p_count(struct dns_packet *, enum dns_section);
+
+DNS_PUBLIC int dns_p_push(struct dns_packet *, enum dns_section, const void *, size_t, enum dns_type, enum dns_class, unsigned, const void *);
+
+DNS_PUBLIC void dns_p_dictadd(struct dns_packet *, unsigned short);
+
+DNS_PUBLIC struct dns_packet *dns_p_merge(struct dns_packet *, enum dns_section, struct dns_packet *, enum dns_section, int *);
+
+DNS_PUBLIC void dns_p_dump(struct dns_packet *, FILE *);
+
+DNS_PUBLIC int dns_p_study(struct dns_packet *);
+
+
+/*
+ * D O M A I N N A M E I N T E R F A C E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_D_MAXLABEL 63 /* + 1 '\0' */
+#define DNS_D_MAXNAME 255 /* + 1 '\0' */
+
+#define DNS_D_ANCHOR 1 /* anchor domain w/ root "." */
+#define DNS_D_CLEAVE 2 /* cleave sub-domain */
+#define DNS_D_TRIM 4 /* remove superfluous dots */
+
+#define dns_d_new3(a, b, f) dns_d_init(&(char[DNS_D_MAXNAME + 1]){ 0 }, DNS_D_MAXNAME + 1, (a), (b), (f))
+#define dns_d_new2(a, f) dns_d_new3((a), strlen((a)), (f))
+#define dns_d_new1(a) dns_d_new3((a), strlen((a)), DNS_D_ANCHOR)
+#define dns_d_new(...) DNS_PP_CALL(DNS_PP_XPASTE(dns_d_new, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__)
+
+DNS_PUBLIC char *dns_d_init(void *, size_t, const void *, size_t, int);
+
+DNS_PUBLIC size_t dns_d_anchor(void *, size_t, const void *, size_t);
+
+DNS_PUBLIC size_t dns_d_cleave(void *, size_t, const void *, size_t);
+
+DNS_PUBLIC size_t dns_d_comp(void *, size_t, const void *, size_t, struct dns_packet *, int *);
+
+DNS_PUBLIC size_t dns_d_expand(void *, size_t, unsigned short, struct dns_packet *, int *);
+
+DNS_PUBLIC unsigned short dns_d_skip(unsigned short, struct dns_packet *);
+
+DNS_PUBLIC int dns_d_push(struct dns_packet *, const void *, size_t);
+
+DNS_PUBLIC size_t dns_d_cname(void *, size_t, const void *, size_t, struct dns_packet *, int *error);
+
+
+/*
+ * R E S O U R C E R E C O R D I N T E R F A C E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_rr {
+ enum dns_section section;
+
+ struct {
+ unsigned short p;
+ unsigned short len;
+ } dn;
+
+ enum dns_type type;
+ enum dns_class class;
+ unsigned ttl;
+
+ struct {
+ unsigned short p;
+ unsigned short len;
+ } rd;
+}; /* struct dns_rr */
+
+
+DNS_PUBLIC int dns_rr_copy(struct dns_packet *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_rr_parse(struct dns_rr *, unsigned short, struct dns_packet *);
+
+DNS_PUBLIC unsigned short dns_rr_skip(unsigned short, struct dns_packet *);
+
+DNS_PUBLIC int dns_rr_cmp(struct dns_rr *, struct dns_packet *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC size_t dns_rr_print(void *, size_t, struct dns_rr *, struct dns_packet *, int *);
+
+
+#define dns_rr_i_new(P, ...) \
+ dns_rr_i_init(&dns_quietinit((struct dns_rr_i){ 0, __VA_ARGS__ }), (P))
+
+struct dns_rr_i {
+ enum dns_section section;
+ const void *name;
+ enum dns_type type;
+ enum dns_class class;
+ const void *data;
+
+ int follow;
+
+ int (*sort)();
+ unsigned args[2];
+
+ struct {
+ unsigned short next;
+ unsigned short count;
+
+ unsigned exec;
+ unsigned regs[2];
+ } state, saved;
+}; /* struct dns_rr_i */
+
+DNS_PUBLIC int dns_rr_i_packet(struct dns_rr *, struct dns_rr *, struct dns_rr_i *, struct dns_packet *);
+
+DNS_PUBLIC int dns_rr_i_order(struct dns_rr *, struct dns_rr *, struct dns_rr_i *, struct dns_packet *);
+
+DNS_PUBLIC int dns_rr_i_shuffle(struct dns_rr *, struct dns_rr *, struct dns_rr_i *, struct dns_packet *);
+
+DNS_PUBLIC struct dns_rr_i *dns_rr_i_init(struct dns_rr_i *, struct dns_packet *);
+
+#define dns_rr_i_save(i) ((i)->saved = (i)->state)
+#define dns_rr_i_rewind(i) ((i)->state = (i)->saved)
+#define dns_rr_i_count(i) ((i)->state.count)
+
+DNS_PUBLIC unsigned dns_rr_grep(struct dns_rr *, unsigned, struct dns_rr_i *, struct dns_packet *, int *);
+
+#define dns_rr_foreach_(rr, P, ...) \
+ for (struct dns_rr_i DNS_PP_XPASTE(i, __LINE__) = *dns_rr_i_new((P), __VA_ARGS__); dns_rr_grep((rr), 1, &DNS_PP_XPASTE(i, __LINE__), (P), &(int){ 0 }); )
+
+#define dns_rr_foreach(...) dns_rr_foreach_(__VA_ARGS__)
+
+
+/*
+ * A R E S O U R C E R E C O R D
+ */
+
+struct dns_a {
+ struct in_addr addr;
+}; /* struct dns_a */
+
+DNS_PUBLIC int dns_a_parse(struct dns_a *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_a_push(struct dns_packet *, struct dns_a *);
+
+DNS_PUBLIC int dns_a_cmp(const struct dns_a *, const struct dns_a *);
+
+DNS_PUBLIC size_t dns_a_print(void *, size_t, struct dns_a *);
+
+DNS_PUBLIC size_t dns_a_arpa(void *, size_t, const struct dns_a *);
+
+
+/*
+ * AAAA R E S O U R C E R E C O R D
+ */
+
+struct dns_aaaa {
+ struct in6_addr addr;
+}; /* struct dns_aaaa */
+
+DNS_PUBLIC int dns_aaaa_parse(struct dns_aaaa *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_aaaa_push(struct dns_packet *, struct dns_aaaa *);
+
+DNS_PUBLIC int dns_aaaa_cmp(const struct dns_aaaa *, const struct dns_aaaa *);
+
+DNS_PUBLIC size_t dns_aaaa_print(void *, size_t, struct dns_aaaa *);
+
+DNS_PUBLIC size_t dns_aaaa_arpa(void *, size_t, const struct dns_aaaa *);
+
+
+/*
+ * MX R E S O U R C E R E C O R D
+ */
+
+struct dns_mx {
+ unsigned short preference;
+ char host[DNS_D_MAXNAME + 1];
+}; /* struct dns_mx */
+
+DNS_PUBLIC int dns_mx_parse(struct dns_mx *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_mx_push(struct dns_packet *, struct dns_mx *);
+
+DNS_PUBLIC int dns_mx_cmp(const struct dns_mx *, const struct dns_mx *);
+
+DNS_PUBLIC size_t dns_mx_print(void *, size_t, struct dns_mx *);
+
+DNS_PUBLIC size_t dns_mx_cname(void *, size_t, struct dns_mx *);
+
+
+/*
+ * NS R E S O U R C E R E C O R D
+ */
+
+struct dns_ns {
+ char host[DNS_D_MAXNAME + 1];
+}; /* struct dns_ns */
+
+DNS_PUBLIC int dns_ns_parse(struct dns_ns *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_ns_push(struct dns_packet *, struct dns_ns *);
+
+DNS_PUBLIC int dns_ns_cmp(const struct dns_ns *, const struct dns_ns *);
+
+DNS_PUBLIC size_t dns_ns_print(void *, size_t, struct dns_ns *);
+
+DNS_PUBLIC size_t dns_ns_cname(void *, size_t, struct dns_ns *);
+
+
+/*
+ * CNAME R E S O U R C E R E C O R D
+ */
+
+struct dns_cname {
+ char host[DNS_D_MAXNAME + 1];
+}; /* struct dns_cname */
+
+DNS_PUBLIC int dns_cname_parse(struct dns_cname *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_cname_push(struct dns_packet *, struct dns_cname *);
+
+DNS_PUBLIC int dns_cname_cmp(const struct dns_cname *, const struct dns_cname *);
+
+DNS_PUBLIC size_t dns_cname_print(void *, size_t, struct dns_cname *);
+
+DNS_PUBLIC size_t dns_cname_cname(void *, size_t, struct dns_cname *);
+
+
+/*
+ * SOA R E S O U R C E R E C O R D
+ */
+
+struct dns_soa {
+ char mname[DNS_D_MAXNAME + 1];
+ char rname[DNS_D_MAXNAME + 1];
+ unsigned serial, refresh, retry, expire, minimum;
+}; /* struct dns_soa */
+
+DNS_PUBLIC int dns_soa_parse(struct dns_soa *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_soa_push(struct dns_packet *, struct dns_soa *);
+
+DNS_PUBLIC int dns_soa_cmp(const struct dns_soa *, const struct dns_soa *);
+
+DNS_PUBLIC size_t dns_soa_print(void *, size_t, struct dns_soa *);
+
+
+/*
+ * PTR R E S O U R C E R E C O R D
+ */
+
+struct dns_ptr {
+ char host[DNS_D_MAXNAME + 1];
+}; /* struct dns_ptr */
+
+DNS_PUBLIC int dns_ptr_parse(struct dns_ptr *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_ptr_push(struct dns_packet *, struct dns_ptr *);
+
+DNS_PUBLIC int dns_ptr_cmp(const struct dns_ptr *, const struct dns_ptr *);
+
+DNS_PUBLIC size_t dns_ptr_print(void *, size_t, struct dns_ptr *);
+
+DNS_PUBLIC size_t dns_ptr_cname(void *, size_t, struct dns_ptr *);
+
+DNS_PUBLIC size_t dns_ptr_qname(void *, size_t, int, void *);
+
+
+/*
+ * SRV R E S O U R C E R E C O R D
+ */
+
+struct dns_srv {
+ unsigned short priority;
+ unsigned short weight;
+ unsigned short port;
+ char target[DNS_D_MAXNAME + 1];
+}; /* struct dns_srv */
+
+DNS_PUBLIC int dns_srv_parse(struct dns_srv *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_srv_push(struct dns_packet *, struct dns_srv *);
+
+DNS_PUBLIC int dns_srv_cmp(const struct dns_srv *, const struct dns_srv *);
+
+DNS_PUBLIC size_t dns_srv_print(void *, size_t, struct dns_srv *);
+
+DNS_PUBLIC size_t dns_srv_cname(void *, size_t, struct dns_srv *);
+
+
+/*
+ * OPT R E S O U R C E R E C O R D
+ */
+
+#ifndef DNS_OPT_MINDATA
+#define DNS_OPT_MINDATA 256
+#endif
+
+#define DNS_OPT_DNSSEC 0x8000
+
+struct dns_opt {
+ enum dns_rcode rcode;
+ unsigned char version;
+ unsigned short flags;
+
+ union {
+ unsigned short maxsize; /* deprecated as confusing */
+ unsigned short maxudp; /* maximum UDP payload size */
+ };
+
+ size_t size, len;
+ unsigned char data[DNS_OPT_MINDATA];
+}; /* struct dns_opt */
+
+#define DNS_OPT_INIT(opt) { .size = sizeof (*opt) - offsetof(struct dns_opt, data) }
+
+DNS_PUBLIC struct dns_opt *dns_opt_init(struct dns_opt *, size_t);
+
+DNS_PUBLIC int dns_opt_parse(struct dns_opt *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_opt_push(struct dns_packet *, struct dns_opt *);
+
+DNS_PUBLIC int dns_opt_cmp(const struct dns_opt *, const struct dns_opt *);
+
+DNS_PUBLIC size_t dns_opt_print(void *, size_t, struct dns_opt *);
+
+DNS_PUBLIC unsigned int dns_opt_ttl(const struct dns_opt *);
+
+DNS_PUBLIC unsigned short dns_opt_class(const struct dns_opt *);
+
+DNS_PUBLIC dns_error_t dns_opt_data_push(struct dns_opt *, unsigned char, unsigned short, const void *);
+
+
+/*
+ * SSHFP R E S O U R C E R E C O R D
+ */
+
+struct dns_sshfp {
+ enum dns_sshfp_key {
+ DNS_SSHFP_RSA = 1,
+ DNS_SSHFP_DSA = 2,
+ } algo;
+
+ enum dns_sshfp_digest {
+ DNS_SSHFP_SHA1 = 1,
+ } type;
+
+ union {
+ unsigned char sha1[20];
+ } digest;
+}; /* struct dns_sshfp */
+
+DNS_PUBLIC int dns_sshfp_parse(struct dns_sshfp *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_sshfp_push(struct dns_packet *, struct dns_sshfp *);
+
+DNS_PUBLIC int dns_sshfp_cmp(const struct dns_sshfp *, const struct dns_sshfp *);
+
+DNS_PUBLIC size_t dns_sshfp_print(void *, size_t, struct dns_sshfp *);
+
+
+/*
+ * TXT R E S O U R C E R E C O R D
+ */
+
+#ifndef DNS_TXT_MINDATA
+#define DNS_TXT_MINDATA 1024
+#endif
+
+struct dns_txt {
+ size_t size, len;
+ unsigned char data[DNS_TXT_MINDATA];
+}; /* struct dns_txt */
+
+DNS_PUBLIC struct dns_txt *dns_txt_init(struct dns_txt *, size_t);
+
+DNS_PUBLIC int dns_txt_parse(struct dns_txt *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_txt_push(struct dns_packet *, struct dns_txt *);
+
+DNS_PUBLIC int dns_txt_cmp(const struct dns_txt *, const struct dns_txt *);
+
+DNS_PUBLIC size_t dns_txt_print(void *, size_t, struct dns_txt *);
+
+
+/*
+ * ANY R E S O U R C E R E C O R D
+ */
+
+union dns_any {
+ struct dns_a a;
+ struct dns_aaaa aaaa;
+ struct dns_mx mx;
+ struct dns_ns ns;
+ struct dns_cname cname;
+ struct dns_soa soa;
+ struct dns_ptr ptr;
+ struct dns_srv srv;
+ struct dns_opt opt;
+ struct dns_sshfp sshfp;
+ struct dns_txt txt, spf, rdata;
+}; /* union dns_any */
+
+#define DNS_ANY_INIT(any) { .rdata = { .size = sizeof *(any) - offsetof(struct dns_txt, data) } }
+
+DNS_PUBLIC union dns_any *dns_any_init(union dns_any *, size_t);
+
+DNS_PUBLIC int dns_any_parse(union dns_any *, struct dns_rr *, struct dns_packet *);
+
+DNS_PUBLIC int dns_any_push(struct dns_packet *, union dns_any *, enum dns_type);
+
+DNS_PUBLIC int dns_any_cmp(const union dns_any *, enum dns_type, const union dns_any *, enum dns_type);
+
+DNS_PUBLIC size_t dns_any_print(void *, size_t, union dns_any *, enum dns_type);
+
+DNS_PUBLIC size_t dns_any_cname(void *, size_t, union dns_any *, enum dns_type);
+
+
+/*
+ * H O S T S I N T E R F A C E
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_hosts;
+
+DNS_PUBLIC struct dns_hosts *dns_hosts_open(int *);
+
+DNS_PUBLIC void dns_hosts_close(struct dns_hosts *);
+
+DNS_PUBLIC dns_refcount_t dns_hosts_acquire(struct dns_hosts *);
+
+DNS_PUBLIC dns_refcount_t dns_hosts_release(struct dns_hosts *);
+
+DNS_PUBLIC struct dns_hosts *dns_hosts_mortal(struct dns_hosts *);
+
+DNS_PUBLIC struct dns_hosts *dns_hosts_local(int *);
+
+DNS_PUBLIC int dns_hosts_loadfile(struct dns_hosts *, FILE *);
+
+DNS_PUBLIC int dns_hosts_loadpath(struct dns_hosts *, const char *);
+
+DNS_PUBLIC int dns_hosts_dump(struct dns_hosts *, FILE *);
+
+DNS_PUBLIC int dns_hosts_insert(struct dns_hosts *, int, const void *, const void *, _Bool);
+
+DNS_PUBLIC struct dns_packet *dns_hosts_query(struct dns_hosts *, struct dns_packet *, int *);
+
+
+/*
+ * R E S O L V . C O N F I N T E R F A C E
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_resolv_conf {
+ struct sockaddr_storage nameserver[3];
+
+ char search[4][DNS_D_MAXNAME + 1];
+
+ /* (f)ile, (b)ind, (c)ache */
+ char lookup[4 * (1 + (4 * 2))];
+
+ /* getaddrinfo family by preference order ("inet4", "inet6") */
+ int family[3];
+
+ struct {
+ _Bool edns0;
+
+ unsigned ndots;
+
+ unsigned timeout;
+
+ unsigned attempts;
+
+ _Bool rotate;
+
+ _Bool recurse;
+
+ _Bool smart;
+
+ enum {
+ DNS_RESCONF_TCP_ENABLE,
+ DNS_RESCONF_TCP_ONLY,
+ DNS_RESCONF_TCP_SOCKS,
+ DNS_RESCONF_TCP_DISABLE,
+ } tcp;
+ } options;
+
+ struct sockaddr_storage iface;
+
+ struct { /* PRIVATE */
+ dns_atomic_t refcount;
+ } _;
+}; /* struct dns_resolv_conf */
+
+DNS_PUBLIC struct dns_resolv_conf *dns_resconf_open(int *);
+
+DNS_PUBLIC void dns_resconf_close(struct dns_resolv_conf *);
+
+DNS_PUBLIC dns_refcount_t dns_resconf_acquire(struct dns_resolv_conf *);
+
+DNS_PUBLIC dns_refcount_t dns_resconf_release(struct dns_resolv_conf *);
+
+DNS_PUBLIC struct dns_resolv_conf *dns_resconf_mortal(struct dns_resolv_conf *);
+
+DNS_PUBLIC struct dns_resolv_conf *dns_resconf_local(int *);
+
+DNS_PUBLIC struct dns_resolv_conf *dns_resconf_root(int *);
+
+DNS_PUBLIC int dns_resconf_pton(struct sockaddr_storage *, const char *);
+
+DNS_PUBLIC int dns_resconf_loadfile(struct dns_resolv_conf *, FILE *);
+
+DNS_PUBLIC int dns_resconf_loadpath(struct dns_resolv_conf *, const char *);
+
+DNS_PUBLIC int dns_nssconf_loadfile(struct dns_resolv_conf *, FILE *);
+
+DNS_PUBLIC int dns_nssconf_loadpath(struct dns_resolv_conf *, const char *);
+
+DNS_PUBLIC int dns_resconf_dump(struct dns_resolv_conf *, FILE *);
+
+DNS_PUBLIC int dns_nssconf_dump(struct dns_resolv_conf *, FILE *);
+
+DNS_PUBLIC int dns_resconf_setiface(struct dns_resolv_conf *, const char *, unsigned short);
+
+typedef unsigned long dns_resconf_i_t;
+
+DNS_PUBLIC size_t dns_resconf_search(void *, size_t, const void *, size_t, struct dns_resolv_conf *, dns_resconf_i_t *);
+
+
+/*
+ * H I N T S E R V E R I N T E R F A C E
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_hints;
+
+DNS_PUBLIC struct dns_hints *dns_hints_open(struct dns_resolv_conf *, int *);
+
+DNS_PUBLIC void dns_hints_close(struct dns_hints *);
+
+DNS_PUBLIC dns_refcount_t dns_hints_acquire(struct dns_hints *);
+
+DNS_PUBLIC dns_refcount_t dns_hints_release(struct dns_hints *);
+
+DNS_PUBLIC struct dns_hints *dns_hints_mortal(struct dns_hints *);
+
+DNS_PUBLIC int dns_hints_insert(struct dns_hints *, const char *, const struct sockaddr *, unsigned);
+
+DNS_PUBLIC unsigned dns_hints_insert_resconf(struct dns_hints *, const char *, const struct dns_resolv_conf *, int *);
+
+DNS_PUBLIC struct dns_hints *dns_hints_local(struct dns_resolv_conf *, int *);
+
+DNS_PUBLIC struct dns_hints *dns_hints_root(struct dns_resolv_conf *, int *);
+
+DNS_PUBLIC struct dns_packet *dns_hints_query(struct dns_hints *, struct dns_packet *, int *);
+
+DNS_PUBLIC int dns_hints_dump(struct dns_hints *, FILE *);
+
+
+struct dns_hints_i {
+ const char *zone;
+
+ struct {
+ unsigned next;
+ unsigned seed;
+ } state;
+}; /* struct dns_hints_i */
+
+#define dns_hints_i_new(...) (&(struct dns_hints_i){ __VA_ARGS__ })
+
+DNS_PUBLIC unsigned dns_hints_grep(struct sockaddr **, socklen_t *, unsigned, struct dns_hints_i *, struct dns_hints *);
+
+
+/*
+ * C A C H E I N T E R F A C E
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_cache {
+ void *state;
+
+ dns_refcount_t (*acquire)(struct dns_cache *);
+ dns_refcount_t (*release)(struct dns_cache *);
+
+ struct dns_packet *(*query)(struct dns_packet *, struct dns_cache *, int *);
+
+ int (*submit)(struct dns_packet *, struct dns_cache *);
+ int (*check)(struct dns_cache *);
+ struct dns_packet *(*fetch)(struct dns_cache *, int *);
+
+ int (*pollfd)(struct dns_cache *);
+ short (*events)(struct dns_cache *);
+ void (*clear)(struct dns_cache *);
+
+ union {
+ long i;
+ void *p;
+ } arg[3];
+
+ struct { /* PRIVATE */
+ dns_atomic_t refcount;
+ } _;
+}; /* struct dns_cache */
+
+
+DNS_PUBLIC struct dns_cache *dns_cache_init(struct dns_cache *);
+
+DNS_PUBLIC void dns_cache_close(struct dns_cache *);
+
+
+/*
+ * A P P L I C A T I O N I N T E R F A C E
+ *
+ * Options to change the behavior of the API. Applies across all the
+ * different components.
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_OPTS_INITIALIZER_ { 0, 0 }, 0, 0
+#define DNS_OPTS_INITIALIZER { DNS_OPTS_INITIALIZER_ }
+#define DNS_OPTS_INIT(...) { DNS_OPTS_INITIALIZER_, __VA_ARGS__ }
+
+#define dns_opts(...) (&dns_quietinit((struct dns_options)DNS_OPTS_INIT(__VA_ARGS__)))
+
+struct dns_options {
+ /*
+ * If the callback closes *fd, it must set it to -1. Otherwise, the
+ * descriptor is queued and lazily closed at object destruction or
+ * by an explicit call to _clear(). This allows safe use of
+ * kqueue(2), epoll(2), et al -style persistent events.
+ */
+ struct {
+ void *arg;
+ int (*cb)(int *fd, void *arg);
+ } closefd;
+
+ /* bitmask for _events() routines */
+ enum dns_events {
+ DNS_SYSPOLL,
+ DNS_LIBEVENT,
+ } events;
+
+ /* Use this SOCKS server. */
+ struct sockaddr_storage *socks_host;
+}; /* struct dns_options */
+
+
+/*
+ * S T A T S I N T E R F A C E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_stat {
+ size_t queries;
+
+ struct {
+ struct {
+ size_t count, bytes;
+ } sent, rcvd;
+ } udp, tcp;
+}; /* struct dns_stat */
+
+
+/*
+ * S O C K E T I N T E R F A C E
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_socket;
+
+DNS_PUBLIC struct dns_socket *dns_so_open(const struct sockaddr *, int, const struct dns_options *, int *error);
+
+DNS_PUBLIC void dns_so_close(struct dns_socket *);
+
+DNS_PUBLIC void dns_so_reset(struct dns_socket *);
+
+DNS_PUBLIC unsigned short dns_so_mkqid(struct dns_socket *so);
+
+DNS_PUBLIC struct dns_packet *dns_so_query(struct dns_socket *, struct dns_packet *, struct sockaddr *, int *);
+
+DNS_PUBLIC int dns_so_submit(struct dns_socket *, struct dns_packet *, struct sockaddr *);
+
+DNS_PUBLIC int dns_so_check(struct dns_socket *);
+
+DNS_PUBLIC struct dns_packet *dns_so_fetch(struct dns_socket *, int *);
+
+DNS_PUBLIC time_t dns_so_elapsed(struct dns_socket *);
+
+DNS_PUBLIC void dns_so_clear(struct dns_socket *);
+
+DNS_PUBLIC int dns_so_events(struct dns_socket *);
+
+DNS_PUBLIC int dns_so_pollfd(struct dns_socket *);
+
+DNS_PUBLIC int dns_so_poll(struct dns_socket *, int);
+
+DNS_PUBLIC const struct dns_stat *dns_so_stat(struct dns_socket *);
+
+DNS_PUBLIC struct dns_trace *dns_so_trace(struct dns_socket *);
+
+DNS_PUBLIC void dns_so_settrace(struct dns_socket *, struct dns_trace *);
+
+
+/*
+ * R E S O L V E R I N T E R F A C E
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_resolver;
+
+DNS_PUBLIC struct dns_resolver *dns_res_open(struct dns_resolv_conf *, struct dns_hosts *hosts, struct dns_hints *, struct dns_cache *, const struct dns_options *, int *);
+
+DNS_PUBLIC struct dns_resolver *dns_res_stub(const struct dns_options *, int *);
+
+DNS_PUBLIC void dns_res_reset(struct dns_resolver *);
+
+DNS_PUBLIC void dns_res_close(struct dns_resolver *);
+
+DNS_PUBLIC dns_refcount_t dns_res_acquire(struct dns_resolver *);
+
+DNS_PUBLIC dns_refcount_t dns_res_release(struct dns_resolver *);
+
+DNS_PUBLIC struct dns_resolver *dns_res_mortal(struct dns_resolver *);
+
+DNS_PUBLIC int dns_res_submit(struct dns_resolver *, const char *, enum dns_type, enum dns_class);
+
+DNS_PUBLIC int dns_res_submit2(struct dns_resolver *, const char *, size_t, enum dns_type, enum dns_class);
+
+DNS_PUBLIC int dns_res_check(struct dns_resolver *);
+
+DNS_PUBLIC struct dns_packet *dns_res_fetch(struct dns_resolver *, int *);
+
+DNS_PUBLIC time_t dns_res_elapsed(struct dns_resolver *);
+
+DNS_PUBLIC void dns_res_clear(struct dns_resolver *);
+
+DNS_PUBLIC int dns_res_events(struct dns_resolver *);
+
+DNS_PUBLIC int dns_res_pollfd(struct dns_resolver *);
+
+DNS_PUBLIC time_t dns_res_timeout(struct dns_resolver *);
+
+DNS_PUBLIC int dns_res_poll(struct dns_resolver *, int);
+
+DNS_PUBLIC struct dns_packet *dns_res_query(struct dns_resolver *, const char *, enum dns_type, enum dns_class, int, int *);
+
+DNS_PUBLIC const struct dns_stat *dns_res_stat(struct dns_resolver *);
+
+DNS_PUBLIC void dns_res_sethints(struct dns_resolver *, struct dns_hints *);
+
+DNS_PUBLIC struct dns_trace *dns_res_trace(struct dns_resolver *);
+
+DNS_PUBLIC void dns_res_settrace(struct dns_resolver *, struct dns_trace *);
+
+
+/*
+ * A D D R I N F O I N T E R F A C E
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+struct dns_addrinfo;
+
+DNS_PUBLIC struct dns_addrinfo *dns_ai_open(const char *, const char *, enum dns_type, const struct addrinfo *, struct dns_resolver *, int *);
+
+DNS_PUBLIC void dns_ai_close(struct dns_addrinfo *);
+
+DNS_PUBLIC int dns_ai_nextent(struct addrinfo **, struct dns_addrinfo *);
+
+DNS_PUBLIC size_t dns_ai_print(void *, size_t, struct addrinfo *, struct dns_addrinfo *);
+
+DNS_PUBLIC time_t dns_ai_elapsed(struct dns_addrinfo *);
+
+DNS_PUBLIC void dns_ai_clear(struct dns_addrinfo *);
+
+DNS_PUBLIC int dns_ai_events(struct dns_addrinfo *);
+
+DNS_PUBLIC int dns_ai_pollfd(struct dns_addrinfo *);
+
+DNS_PUBLIC time_t dns_ai_timeout(struct dns_addrinfo *);
+
+DNS_PUBLIC int dns_ai_poll(struct dns_addrinfo *, int);
+
+DNS_PUBLIC const struct dns_stat *dns_ai_stat(struct dns_addrinfo *);
+
+DNS_PUBLIC struct dns_trace *dns_ai_trace(struct dns_addrinfo *);
+
+DNS_PUBLIC void dns_ai_settrace(struct dns_addrinfo *, struct dns_trace *);
+
+
+/*
+ * Q U E R Y T R A C I N G I N T E R F A C E
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_TRACE_ID_C(n) UINT64_C(n)
+typedef uint64_t dns_trace_id_t;
+
+#define DNS_TRACE_ABI 0x20160803
+
+struct dns_trace_event {
+ enum {
+ DNS_TE_RES_SUBMIT = 1,
+ DNS_TE_RES_FETCH = 99,
+
+ DNS_TE_SO_SUBMIT = 100,
+ DNS_TE_SO_VERIFY,
+ DNS_TE_SO_FETCH = 199,
+
+ DNS_TE_SYS_CONNECT = 200,
+ DNS_TE_SYS_SEND,
+ DNS_TE_SYS_RECV,
+ } type;
+
+ size_t size;
+ dns_trace_id_t id;
+ struct timespec ts;
+ int abi;
+
+ union {
+ struct {
+ char qname[DNS_D_MAXNAME + 1];
+ enum dns_type qtype;
+ enum dns_class qclass;
+ int error;
+ } res_submit;
+
+ struct {
+ int error;
+ } res_fetch;
+
+ struct {
+ struct sockaddr_storage haddr;
+ char hname[DNS_D_MAXNAME + 1];
+ int error;
+ } so_submit;
+
+ struct {
+ int error;
+ } so_verify;
+
+ struct {
+ int error;
+ } so_fetch;
+
+ struct {
+ struct sockaddr_storage src, dst;
+ int socktype;
+ dns_error_t error;
+ } sys_connect, sys_send, sys_recv;
+ };
+
+ unsigned char data[];
+};
+
+static inline size_t dns_te_datasize(const struct dns_trace_event *te) {
+ size_t n = offsetof(struct dns_trace_event, data);
+ return (n <= te->size)? te->size - n : 0;
+}
+
+struct dns_trace;
+
+DNS_PUBLIC int dns_trace_abi(void);
+
+DNS_PUBLIC struct dns_trace *dns_trace_open(FILE *, dns_error_t *);
+
+DNS_PUBLIC void dns_trace_close(struct dns_trace *);
+
+DNS_PUBLIC dns_refcount_t dns_trace_acquire(struct dns_trace *);
+
+DNS_PUBLIC dns_refcount_t dns_trace_release(struct dns_trace *);
+
+DNS_PUBLIC dns_trace_id_t dns_trace_id(struct dns_trace *);
+
+DNS_PUBLIC dns_trace_id_t dns_trace_setid(struct dns_trace *, dns_trace_id_t);
+
+DNS_PUBLIC struct dns_trace_event *dns_trace_get(struct dns_trace *, struct dns_trace_event **, dns_error_t *);
+
+DNS_PUBLIC struct dns_trace_event *dns_trace_tag(struct dns_trace *, struct dns_trace_event *);
+
+DNS_PUBLIC dns_error_t dns_trace_put(struct dns_trace *, const struct dns_trace_event *, const void *, size_t);
+
+DNS_PUBLIC dns_error_t dns_trace_dump(struct dns_trace *, FILE *);
+
+DNS_PUBLIC struct dns_trace_event *dns_trace_fget(struct dns_trace_event **, FILE *, dns_error_t *);
+
+DNS_PUBLIC dns_error_t dns_trace_fput(const struct dns_trace_event *, const void *, size_t, FILE *);
+
+
+/*
+ * U T I L I T Y I N T E R F A C E S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+DNS_PUBLIC size_t dns_strlcpy(char *, const char *, size_t);
+
+DNS_PUBLIC size_t dns_strlcat(char *, const char *, size_t);
+
+
+/*
+ * M A C R O M A G I C S
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define DNS_PP_MIN(a, b) (((a) < (b))? (a) : (b))
+#define DNS_PP_MAX(a, b) (((a) > (b))? (a) : (b))
+#define DNS_PP_NARG_(a, b, c, d, e, f, g, h, i, j, k, N,...) N
+#define DNS_PP_NARG(...) DNS_PP_NARG_(__VA_ARGS__, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
+#define DNS_PP_CALL(F, ...) F(__VA_ARGS__)
+#define DNS_PP_PASTE(x, y) x##y
+#define DNS_PP_XPASTE(x, y) DNS_PP_PASTE(x, y)
+#define DNS_PP_STRINGIFY_(s) #s
+#define DNS_PP_STRINGIFY(s) DNS_PP_STRINGIFY_(s)
+#define DNS_PP_D1 0
+#define DNS_PP_D2 1
+#define DNS_PP_D3 2
+#define DNS_PP_D4 3
+#define DNS_PP_D5 4
+#define DNS_PP_D6 5
+#define DNS_PP_D7 6
+#define DNS_PP_D8 7
+#define DNS_PP_D9 8
+#define DNS_PP_D10 9
+#define DNS_PP_D11 10
+#define DNS_PP_DEC(N) DNS_PP_XPASTE(DNS_PP_D, N)
+
+#endif /* DNS_H */
--
Alioth's /usr/local/bin/git-commit-notice on /srv/git.debian.org/git/pkg-gnupg/gnupg2.git
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