[pkg-dhcp-devel] Bug#863426: isc-dhcp: dhclient DHCPv6 does not work with interface alias

[Dan Streetman]

Package: isc-dhcp
Version: 4.3.5-3
Severity: normal
Tags: patch
User: ubuntu-devel at lists.ubuntu.com
Usertags: origin-ubuntu artful ubuntu-patch

Dear Maintainer,

dhclient does not work when doing DHCPv6 with an interface alias, e.g.

dhclient -6 -v eth0:1

fails.  The attached patch is required to fix it.

  * When comparing enumerated interface name with cmdline interface name,
    the cmdline interface name alias extension must be stripped since all
    enumerated interface names have their alias extension stripped.
    Without this, DHCPv6 fails for interface aliases. (LP: #1693819)


Thanks for considering the patch.


-- System Information:
Debian Release: stretch/sid
  APT prefers zesty-updates
  APT policy: (500, 'zesty-updates'), (500, 'zesty-security'), (500, 'zesty'), (100, 'zesty-backports')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.10.0-20-generic (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
-------------- next part --------------
diff -Nru isc-dhcp-4.3.5/debian/control isc-dhcp-4.3.5/debian/control
--- isc-dhcp-4.3.5/debian/control	2017-01-19 12:11:21.000000000 -0500
+++ isc-dhcp-4.3.5/debian/control	2017-05-26 10:57:51.000000000 -0400
@@ -1,8 +1,7 @@
 Source: isc-dhcp
 Section: net
 Priority: important
-Maintainer: Ubuntu Developers <ubuntu-devel-discuss at lists.ubuntu.com>
-XSBC-Original-Maintainer: Debian ISC DHCP maintainers <pkg-dhcp-devel at lists.alioth.debian.org>
+Maintainer: Debian ISC DHCP maintainers <pkg-dhcp-devel at lists.alioth.debian.org>
 Uploaders: Andrew Pollock <apollock at debian.org>, Michael Gilbert <mgilbert at debian.org>
 Vcs-Git: https://anonscm.debian.org/pkg-dhcp/isc-dhcp.git
 Vcs-Browser: https://anonscm.debian.org/gitweb/?p=pkg-dhcp/isc-dhcp.git;a=summary
diff -Nru isc-dhcp-4.3.5/debian/patches/series isc-dhcp-4.3.5/debian/patches/series
--- isc-dhcp-4.3.5/debian/patches/series	2017-01-19 12:11:21.000000000 -0500
+++ isc-dhcp-4.3.5/debian/patches/series	2017-05-26 10:57:24.000000000 -0400
@@ -32,3 +32,4 @@
 dhcp-improved-xid-correct-byte-order.patch
 dhcp-4.2.4-dhclient-options-changed.patch
 ubuntu-dhcpd-conf.patch
+strip-alias-when-comparing-interface-names.patch
diff -Nru isc-dhcp-4.3.5/debian/patches/strip-alias-when-comparing-interface-names.patch isc-dhcp-4.3.5/debian/patches/strip-alias-when-comparing-interface-names.patch
--- isc-dhcp-4.3.5/debian/patches/strip-alias-when-comparing-interface-names.patch	1969-12-31 19:00:00.000000000 -0500
+++ isc-dhcp-4.3.5/debian/patches/strip-alias-when-comparing-interface-names.patch	2017-05-26 10:57:32.000000000 -0400
@@ -0,0 +1,40 @@
+Author: Dan Streetman <dan.streetman at canonical.com>
+Description: Since isc-dhcp strips the interface alias from all
+  interfaces it enumerates, when comparing the cmdline interface
+  name to find the matching enumerated interface, the cmdline name
+  must have its alias stripped also.  Without this, DHCPv6 fails
+  when using an interface alias.
+Forwarded: yes
+Bug: [ISC bug tracking is private; bug email has been sent]
+Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1693819
+
+---
+ common/discover.c | 15 ++++++++++++++-
+ 1 file changed, 14 insertions(+), 1 deletion(-)
+
+Index: isc-dhcp-4.3.5/common/discover.c
+===================================================================
+--- isc-dhcp-4.3.5.orig/common/discover.c
++++ isc-dhcp-4.3.5/common/discover.c
+@@ -600,7 +600,20 @@ discover_interfaces(int state) {
+ 
+ 		/* See if we've seen an interface that matches this one. */
+ 		for (tmp = interfaces; tmp; tmp = tmp->next) {
+-			if (!strcmp(tmp->name, info.name))
++#if defined(sun) || defined(__linux)
++			char *s, n[IFNAMSIZ];
++
++			strcpy(n, tmp->name);
++			/* next_iface() strips the interface alias,
++			 * so we mustn't include it when strcmp */
++			s = strchr(n, ':');
++			if (s != NULL) {
++				*s = '\0';
++			}
++#else
++			char *n = tmp->name;
++#endif /* defined(sun) || defined(__linux) */
++			if (!strcmp(n, info.name))
+ 				break;
+ 		}
+