[pkg-dhcp-commits] [SCM] ISC DHCP packaging for Debian branch, master, updated. upstream/4.1.1-P1-102-g6343776

Andrew Pollock apollock at debian.org
Sat Nov 27 07:13:00 UTC 2010


The following commit has been merged in the master branch:
commit 6343776966a118c08f824a490a45d55e278e8d9f
Author: Andrew Pollock <apollock at debian.org>
Date:   Fri Nov 26 23:13:25 2010 -0800

    Patch for CVE-2010-3611

diff --git a/debian/changelog b/debian/changelog
index d4e288b..dd2c119 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+isc-dhcp (4.1.1-P1-14) unstable; urgency=low
+
+  * Backport fix for CVE-2010-3611 from 4.1.2
+
+ -- Andrew Pollock <apollock at debian.org>  Fri, 19 Nov 2010 20:54:19 -0800
+
 isc-dhcp (4.1.1-P1-13) unstable; urgency=low
 
   * Updated Spanish debconf template translation (closes: #603122)
diff --git a/debian/patches/00list b/debian/patches/00list
index 7e88556..9210708 100644
--- a/debian/patches/00list
+++ b/debian/patches/00list
@@ -9,6 +9,9 @@ fix_exit_hook_doc_manpage
 # I think this has been independently emailed upstream
 no_loopback_checksum
 
+# Backported from 4.1.2
+CVE-2010-3611
+
 # must be applied before the LDAP stuff
 no-libcrypto
 
diff --git a/debian/patches/CVE-2010-3611.dpatch b/debian/patches/CVE-2010-3611.dpatch
new file mode 100755
index 0000000..bac0141
--- /dev/null
+++ b/debian/patches/CVE-2010-3611.dpatch
@@ -0,0 +1,5985 @@
+#! /bin/sh /usr/share/dpatch/dpatch-run
+## CVE-2010-3611.dpatch by  <apollock at debian.org>
+##
+## All lines beginning with `## DP:' are a description of the patch.
+## DP: Backport of fix in 4.1.2
+## DP: Stolen from https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2010-3611
+
+ at DPATCH@
+diff -urNad isc-dhcp~/server/dhcpv6.c isc-dhcp/server/dhcpv6.c
+--- isc-dhcp~/server/dhcpv6.c	2010-06-06 23:02:45.000000000 -0700
++++ isc-dhcp/server/dhcpv6.c	2010-11-19 20:53:11.000000000 -0800
+@@ -4196,10 +4196,25 @@
+ 	 * If there is no link address, we will use the interface
+ 	 * that this packet came in on to pick the shared_network.
+ 	 */
+-	} else {
++	} else if (packet->interface != NULL) {
+ 		status = shared_network_reference(shared,
+ 					 packet->interface->shared_network,
+ 					 MDL);
++                if (packet->dhcpv6_container_packet != NULL) {
++			log_info("[L2 Relay] No link address in relay packet "
++				 "assuming L2 relay and using receiving "
++				 "interface");
++                }
++
++	} else {
++		/*
++		 * We shouldn't be able to get here but if there is no link
++		 * address and no interface we don't know where to get the
++		 * pool from log an error and return an error.
++		 */
++		log_error("No interface and no link address " 
++			  "can't determine pool");
++		status = ISC_R_INVALIDARG;
+ 	}
+ 
+ 	return status;
+@@ -5487,6 +5502,7 @@
+ 
+ 	enc_packet->client_port = packet->client_port;
+ 	enc_packet->client_addr = packet->client_addr;
++	interface_reference(&enc_packet->interface, packet->interface, MDL);
+ 	enc_packet->dhcpv6_container_packet = packet;
+ 
+ 	msg_type = enc_opt_data.data[0];
+diff -urNad isc-dhcp~/server/dhcpv6.c.orig isc-dhcp/server/dhcpv6.c.orig
+--- isc-dhcp~/server/dhcpv6.c.orig	1969-12-31 16:00:00.000000000 -0800
++++ isc-dhcp/server/dhcpv6.c.orig	2010-06-06 23:02:45.000000000 -0700
+@@ -0,0 +1,5935 @@
++/*
++ * Copyright (C) 2006-2010 by Internet Systems Consortium, Inc. ("ISC")
++ *
++ * Permission to use, copy, modify, and distribute this software for any
++ * purpose with or without fee is hereby granted, provided that the above
++ * copyright notice and this permission notice appear in all copies.
++ *
++ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
++ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
++ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
++ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
++ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
++ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
++ * PERFORMANCE OF THIS SOFTWARE.
++ */
++
++#include "dhcpd.h"
++
++#ifdef DHCPv6
++
++/*
++ * We use print_hex_1() to output DUID values. We could actually output 
++ * the DUID with more information... MAC address if using type 1 or 3, 
++ * and so on. However, RFC 3315 contains Grave Warnings against actually 
++ * attempting to understand a DUID.
++ */
++
++/* 
++ * TODO: gettext() or other method of localization for the messages
++ *       for status codes (and probably for log formats eventually)
++ * TODO: refactoring (simplify, simplify, simplify)
++ * TODO: support multiple shared_networks on each interface (this 
++ *       will allow the server to issue multiple IPv6 addresses to 
++ *       a single interface)
++ */
++
++/*
++ * DHCPv6 Reply workflow assist.  A Reply packet is built by various
++ * different functions; this gives us one location where we keep state
++ * regarding a reply.
++ */
++struct reply_state {
++	/* root level persistent state */
++	struct shared_network *shared;
++	struct host_decl *host;
++	struct subnet *subnet; /* Used to match fixed-addrs to subnet scopes. */
++	struct option_state *opt_state;
++	struct packet *packet;
++	struct data_string client_id;
++
++	/* IA level persistent state */
++	unsigned ia_count;
++	unsigned pd_count;
++	unsigned client_resources;
++	isc_boolean_t resources_included;
++	isc_boolean_t static_lease;
++	unsigned static_prefixes;
++	struct ia_xx *ia;
++	struct ia_xx *old_ia;
++	struct option_state *reply_ia;
++	struct data_string fixed;
++
++	/* IAADDR/PREFIX level persistent state */
++	struct iasubopt *lease;
++
++	/*
++	 * "t1", "t2", preferred, and valid lifetimes records for calculating
++	 * t1 and t2 (min/max).
++	 */
++	u_int32_t renew, rebind, prefer, valid;
++
++	/* Client-requested valid and preferred lifetimes. */
++	u_int32_t client_valid, client_prefer;
++
++	/* Chosen values to transmit for valid and preferred lifetimes. */
++	u_int32_t send_valid, send_prefer;
++
++	/* Preferred prefix length (-1 is any). */
++	int preflen;
++
++	/* Index into the data field that has been consumed. */
++	unsigned cursor;
++
++	union reply_buffer {
++		unsigned char data[65536];
++		struct dhcpv6_packet reply;
++	} buf;
++};
++
++/* 
++ * Prototypes local to this file.
++ */
++static int get_encapsulated_IA_state(struct option_state **enc_opt_state,
++				     struct data_string *enc_opt_data,
++				     struct packet *packet,
++				     struct option_cache *oc,
++				     int offset);
++static void build_dhcpv6_reply(struct data_string *, struct packet *);
++static isc_result_t shared_network_from_packet6(struct shared_network **shared,
++						struct packet *packet);
++static void seek_shared_host(struct host_decl **hp,
++			     struct shared_network *shared);
++static isc_boolean_t fixed_matches_shared(struct host_decl *host,
++					  struct shared_network *shared);
++static isc_result_t reply_process_ia_na(struct reply_state *reply,
++					struct option_cache *ia);
++static isc_result_t reply_process_ia_ta(struct reply_state *reply,
++					struct option_cache *ia);
++static isc_result_t reply_process_addr(struct reply_state *reply,
++				       struct option_cache *addr);
++static isc_boolean_t address_is_owned(struct reply_state *reply,
++				      struct iaddr *addr);
++static isc_boolean_t temporary_is_available(struct reply_state *reply,
++					    struct iaddr *addr);
++static isc_result_t find_client_temporaries(struct reply_state *reply);
++static isc_result_t reply_process_try_addr(struct reply_state *reply,
++					   struct iaddr *addr);
++static isc_result_t find_client_address(struct reply_state *reply);
++static isc_result_t reply_process_is_addressed(struct reply_state *reply,
++					       struct binding_scope **scope,
++					       struct group *group);
++static isc_result_t reply_process_send_addr(struct reply_state *reply,
++					    struct iaddr *addr);
++static struct iasubopt *lease_compare(struct iasubopt *alpha,
++				      struct iasubopt *beta);
++static isc_result_t reply_process_ia_pd(struct reply_state *reply,
++					struct option_cache *ia_pd);
++static isc_result_t reply_process_prefix(struct reply_state *reply,
++					 struct option_cache *pref);
++static isc_boolean_t prefix_is_owned(struct reply_state *reply,
++				     struct iaddrcidrnet *pref);
++static isc_result_t find_client_prefix(struct reply_state *reply);
++static isc_result_t reply_process_try_prefix(struct reply_state *reply,
++					     struct iaddrcidrnet *pref);
++static isc_result_t reply_process_is_prefixed(struct reply_state *reply,
++					      struct binding_scope **scope,
++					      struct group *group);
++static isc_result_t reply_process_send_prefix(struct reply_state *reply,
++					      struct iaddrcidrnet *pref);
++static struct iasubopt *prefix_compare(struct reply_state *reply,
++				       struct iasubopt *alpha,
++				       struct iasubopt *beta);
++
++/*
++ * This function returns the time since DUID time start for the
++ * given time_t value.
++ */
++static u_int32_t
++duid_time(time_t when) {
++	/*
++	 * This time is modulo 2^32.
++	 */
++	while ((when - DUID_TIME_EPOCH) > 4294967295u) {
++		/* use 2^31 to avoid spurious compiler warnings */
++		when -= 2147483648u;
++		when -= 2147483648u;
++	}
++
++	return when - DUID_TIME_EPOCH;
++}
++
++
++/* 
++ * Server DUID.
++ *
++ * This must remain the same for the lifetime of this server, because
++ * clients return the server DUID that we sent them in Request packets.
++ *
++ * We pick the server DUID like this:
++ *
++ * 1. Check dhcpd.conf - any value the administrator has configured 
++ *    overrides any possible values.
++ * 2. Check the leases.txt - we want to use the previous value if 
++ *    possible.
++ * 3. Check if dhcpd.conf specifies a type of server DUID to use,
++ *    and generate that type.
++ * 4. Generate a type 1 (time + hardware address) DUID.
++ */
++static struct data_string server_duid;
++
++/*
++ * Check if the server_duid has been set.
++ */
++isc_boolean_t
++server_duid_isset(void) {
++	return (server_duid.data != NULL);
++}
++
++/*
++ * Return the server_duid.
++ */
++void
++copy_server_duid(struct data_string *ds, const char *file, int line) {
++	data_string_copy(ds, &server_duid, file, line);
++}
++
++/*
++ * Set the server DUID to a specified value. This is used when
++ * the server DUID is stored in persistent memory (basically the
++ * leases.txt file).
++ */
++void
++set_server_duid(struct data_string *new_duid) {
++	/* INSIST(new_duid != NULL); */
++	/* INSIST(new_duid->data != NULL); */
++
++	if (server_duid_isset()) {
++		data_string_forget(&server_duid, MDL);
++	}
++	data_string_copy(&server_duid, new_duid, MDL);
++}
++
++
++/*
++ * Set the server DUID based on the D6O_SERVERID option. This handles
++ * the case where the administrator explicitly put it in the dhcpd.conf 
++ * file.
++ */
++isc_result_t
++set_server_duid_from_option(void) {
++	struct option_state *opt_state;
++	struct option_cache *oc;
++	struct data_string option_duid;
++	isc_result_t ret_val;
++
++	opt_state = NULL;
++	if (!option_state_allocate(&opt_state, MDL)) {
++		log_fatal("No memory for server DUID.");
++	}
++
++	execute_statements_in_scope(NULL, NULL, NULL, NULL, NULL,
++				    opt_state, &global_scope, root_group, NULL);
++
++	oc = lookup_option(&dhcpv6_universe, opt_state, D6O_SERVERID);
++	if (oc == NULL) {
++		ret_val = ISC_R_NOTFOUND;
++	} else {
++		memset(&option_duid, 0, sizeof(option_duid));
++		if (!evaluate_option_cache(&option_duid, NULL, NULL, NULL,
++					   opt_state, NULL, &global_scope,
++					   oc, MDL)) {
++			ret_val = ISC_R_UNEXPECTED;
++		} else {
++			set_server_duid(&option_duid);
++			data_string_forget(&option_duid, MDL);
++			ret_val = ISC_R_SUCCESS;
++		}
++	}
++
++	option_state_dereference(&opt_state, MDL);
++
++	return ret_val;
++}
++
++/*
++ * DUID layout, as defined in RFC 3315, section 9.
++ * 
++ * We support type 1 (hardware address plus time) and type 3 (hardware
++ * address).
++ *
++ * We can support type 2 for specific vendors in the future, if they 
++ * publish the specification. And of course there may be additional
++ * types later.
++ */
++static int server_duid_type = DUID_LLT;
++
++/* 
++ * Set the DUID type.
++ */
++void
++set_server_duid_type(int type) {
++	server_duid_type = type;
++}
++
++/*
++ * Generate a new server DUID. This is done if there was no DUID in 
++ * the leases.txt or in the dhcpd.conf file.
++ */
++isc_result_t
++generate_new_server_duid(void) {
++	struct interface_info *p;
++	u_int32_t time_val;
++	struct data_string generated_duid;
++
++	/*
++	 * Verify we have a type that we support.
++	 */
++	if ((server_duid_type != DUID_LL) && (server_duid_type != DUID_LLT)) {
++		log_error("Invalid DUID type %d specified, "
++			  "only LL and LLT types supported", server_duid_type);
++		return ISC_R_INVALIDARG;
++	}
++
++	/*
++	 * Find an interface with a hardware address.
++	 * Any will do. :)
++	 */
++	for (p = interfaces; p != NULL; p = p->next) {
++		if (p->hw_address.hlen > 0) {
++			break;
++		}
++	}
++	if (p == NULL) {
++		return ISC_R_UNEXPECTED;
++	}
++
++	/*
++	 * Build our DUID.
++	 */
++	memset(&generated_duid, 0, sizeof(generated_duid));
++	if (server_duid_type == DUID_LLT) {
++		time_val = duid_time(time(NULL));
++		generated_duid.len = 8 + p->hw_address.hlen - 1;
++		if (!buffer_allocate(&generated_duid.buffer,
++				     generated_duid.len, MDL)) {
++			log_fatal("No memory for server DUID.");
++		}
++		generated_duid.data = generated_duid.buffer->data;
++		putUShort(generated_duid.buffer->data, DUID_LLT);
++		putUShort(generated_duid.buffer->data + 2,
++			  p->hw_address.hbuf[0]);
++		putULong(generated_duid.buffer->data + 4, time_val);
++		memcpy(generated_duid.buffer->data + 8,
++		       p->hw_address.hbuf+1, p->hw_address.hlen-1);
++	} else if (server_duid_type == DUID_LL) {
++		generated_duid.len = 4 + p->hw_address.hlen - 1;
++		if (!buffer_allocate(&generated_duid.buffer,
++				     generated_duid.len, MDL)) {
++			log_fatal("No memory for server DUID.");
++		}
++		generated_duid.data = generated_duid.buffer->data;
++		putUShort(generated_duid.buffer->data, DUID_LL);
++		putUShort(generated_duid.buffer->data + 2,
++			  p->hw_address.hbuf[0]);
++		memcpy(generated_duid.buffer->data + 4,
++		       p->hw_address.hbuf+1, p->hw_address.hlen-1);
++	} else {
++		log_fatal("Unsupported server DUID type %d.", server_duid_type);
++	}
++
++	set_server_duid(&generated_duid);
++	data_string_forget(&generated_duid, MDL);
++
++	return ISC_R_SUCCESS;
++}
++
++/*
++ * Get the client identifier from the packet.
++ */
++isc_result_t
++get_client_id(struct packet *packet, struct data_string *client_id) {
++	struct option_cache *oc;
++
++	/*
++	 * Verify our client_id structure is empty.
++	 */
++	if ((client_id->data != NULL) || (client_id->len != 0)) {
++		return ISC_R_INVALIDARG;
++	}
++
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_CLIENTID);
++	if (oc == NULL) {
++		return ISC_R_NOTFOUND;
++	}
++
++	if (!evaluate_option_cache(client_id, packet, NULL, NULL,
++				   packet->options, NULL,
++				   &global_scope, oc, MDL)) {
++		return ISC_R_FAILURE;
++	}
++
++	return ISC_R_SUCCESS;
++}
++
++/*
++ * Message validation, defined in RFC 3315, sections 15.2, 15.5, 15.7:
++ *
++ *    Servers MUST discard any Solicit messages that do not include a
++ *    Client Identifier option or that do include a Server Identifier
++ *    option.
++ */
++int
++valid_client_msg(struct packet *packet, struct data_string *client_id) {
++	int ret_val;
++	struct option_cache *oc;
++	struct data_string data;
++
++	ret_val = 0;
++	memset(client_id, 0, sizeof(*client_id));
++	memset(&data, 0, sizeof(data));
++
++	switch (get_client_id(packet, client_id)) {
++		case ISC_R_SUCCESS:
++			break;
++		case ISC_R_NOTFOUND:
++			log_debug("Discarding %s from %s; "
++				  "client identifier missing",
++				  dhcpv6_type_names[packet->dhcpv6_msg_type],
++				  piaddr(packet->client_addr));
++			goto exit;
++		default:
++			log_error("Error processing %s from %s; "
++				  "unable to evaluate Client Identifier",
++				  dhcpv6_type_names[packet->dhcpv6_msg_type],
++				  piaddr(packet->client_addr));
++			goto exit;
++	}
++
++	/*
++	 * Required by RFC 3315, section 15.
++	 */
++	if (packet->unicast) {
++		log_debug("Discarding %s from %s; packet sent unicast "
++			  "(CLIENTID %s)",
++			  dhcpv6_type_names[packet->dhcpv6_msg_type],
++			  piaddr(packet->client_addr),
++			  print_hex_1(client_id->len, client_id->data, 60));
++		goto exit;
++	}
++
++
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_SERVERID);
++	if (oc != NULL) {
++		if (evaluate_option_cache(&data, packet, NULL, NULL,
++					  packet->options, NULL,
++					  &global_scope, oc, MDL)) {
++			log_debug("Discarding %s from %s; "
++				  "server identifier found "
++				  "(CLIENTID %s, SERVERID %s)",
++				  dhcpv6_type_names[packet->dhcpv6_msg_type],
++				  piaddr(packet->client_addr),
++				  print_hex_1(client_id->len,
++				  	      client_id->data, 60),
++				  print_hex_2(data.len,
++				  	      data.data, 60));
++		} else {
++			log_debug("Discarding %s from %s; "
++				  "server identifier found "
++				  "(CLIENTID %s)",
++				  dhcpv6_type_names[packet->dhcpv6_msg_type],
++				  print_hex_1(client_id->len,
++				  	      client_id->data, 60),
++				  piaddr(packet->client_addr));
++		}
++		goto exit;
++	}
++
++	/* looks good */
++	ret_val = 1;
++
++exit:
++	if (data.len > 0) {
++		data_string_forget(&data, MDL);
++	}
++	if (!ret_val) {
++		if (client_id->len > 0) {
++			data_string_forget(client_id, MDL);
++		}
++	}
++	return ret_val;
++}
++
++/*
++ * Response validation, defined in RFC 3315, sections 15.4, 15.6, 15.8, 
++ * 15.9 (slightly different wording, but same meaning):
++ *
++ *   Servers MUST discard any received Request message that meet any of
++ *   the following conditions:
++ *
++ *   -  the message does not include a Server Identifier option.
++ *   -  the contents of the Server Identifier option do not match the
++ *      server's DUID.
++ *   -  the message does not include a Client Identifier option.
++ */
++int
++valid_client_resp(struct packet *packet,
++		  struct data_string *client_id,
++		  struct data_string *server_id)
++{
++	int ret_val;
++	struct option_cache *oc;
++
++	/* INSIST((duid.data != NULL) && (duid.len > 0)); */
++
++	ret_val = 0;
++	memset(client_id, 0, sizeof(*client_id));
++	memset(server_id, 0, sizeof(*server_id));
++
++	switch (get_client_id(packet, client_id)) {
++		case ISC_R_SUCCESS:
++			break;
++		case ISC_R_NOTFOUND:
++			log_debug("Discarding %s from %s; "
++				  "client identifier missing",
++				  dhcpv6_type_names[packet->dhcpv6_msg_type],
++				  piaddr(packet->client_addr));
++			goto exit;
++		default:
++			log_error("Error processing %s from %s; "
++				  "unable to evaluate Client Identifier",
++				  dhcpv6_type_names[packet->dhcpv6_msg_type],
++				  piaddr(packet->client_addr));
++			goto exit;
++	}
++
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_SERVERID);
++	if (oc == NULL) {
++		log_debug("Discarding %s from %s: "
++			  "server identifier missing (CLIENTID %s)",
++			  dhcpv6_type_names[packet->dhcpv6_msg_type],
++			  piaddr(packet->client_addr),
++			  print_hex_1(client_id->len, client_id->data, 60));
++		goto exit;
++	}
++	if (!evaluate_option_cache(server_id, packet, NULL, NULL,
++				   packet->options, NULL,
++				   &global_scope, oc, MDL)) {
++		log_error("Error processing %s from %s; "
++			  "unable to evaluate Server Identifier (CLIENTID %s)",
++			  dhcpv6_type_names[packet->dhcpv6_msg_type],
++			  piaddr(packet->client_addr),
++			  print_hex_1(client_id->len, client_id->data, 60));
++		goto exit;
++	}
++	if ((server_duid.len != server_id->len) ||
++	    (memcmp(server_duid.data, server_id->data, server_duid.len) != 0)) {
++		log_debug("Discarding %s from %s; "
++			  "not our server identifier "
++			  "(CLIENTID %s, SERVERID %s, server DUID %s)",
++			  dhcpv6_type_names[packet->dhcpv6_msg_type],
++			  piaddr(packet->client_addr),
++			  print_hex_1(client_id->len, client_id->data, 60),
++			  print_hex_2(server_id->len, server_id->data, 60),
++			  print_hex_3(server_duid.len, server_duid.data, 60));
++		goto exit;
++	}
++
++	/* looks good */
++	ret_val = 1;
++
++exit:
++	if (!ret_val) {
++		if (server_id->len > 0) {
++			data_string_forget(server_id, MDL);
++		}
++		if (client_id->len > 0) {
++			data_string_forget(client_id, MDL);
++		}
++	}
++	return ret_val;
++}
++
++/*
++ * Information request validation, defined in RFC 3315, section 15.12:
++ *
++ *   Servers MUST discard any received Information-request message that
++ *   meets any of the following conditions:
++ *
++ *   -  The message includes a Server Identifier option and the DUID in
++ *      the option does not match the server's DUID.
++ *
++ *   -  The message includes an IA option.
++ */
++int
++valid_client_info_req(struct packet *packet, struct data_string *server_id) {
++	int ret_val;
++	struct option_cache *oc;
++	struct data_string client_id;
++	char client_id_str[80];	/* print_hex_1() uses maximum 60 characters,
++				   plus a few more for extra information */
++
++	ret_val = 0;
++	memset(server_id, 0, sizeof(*server_id));
++
++	/*
++	 * Make a string that we can print out to give more 
++	 * information about the client if we need to.
++	 *
++	 * By RFC 3315, Section 18.1.5 clients SHOULD have a 
++	 * client-id on an Information-request packet, but it 
++	 * is not strictly necessary.
++	 */
++	if (get_client_id(packet, &client_id) == ISC_R_SUCCESS) {
++		snprintf(client_id_str, sizeof(client_id_str), " (CLIENTID %s)",
++			 print_hex_1(client_id.len, client_id.data, 60));
++		data_string_forget(&client_id, MDL);
++	} else {
++		client_id_str[0] = '\0';
++	}
++
++	/*
++	 * Required by RFC 3315, section 15.
++	 */
++	if (packet->unicast) {
++		log_debug("Discarding %s from %s; packet sent unicast%s",
++			  dhcpv6_type_names[packet->dhcpv6_msg_type],
++			  piaddr(packet->client_addr), client_id_str);
++		goto exit;
++	}
++
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_IA_NA);
++	if (oc != NULL) {
++		log_debug("Discarding %s from %s; "
++			  "IA_NA option present%s",
++			  dhcpv6_type_names[packet->dhcpv6_msg_type],
++			  piaddr(packet->client_addr), client_id_str);
++		goto exit;
++	}
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_IA_TA);
++	if (oc != NULL) {
++		log_debug("Discarding %s from %s; "
++			  "IA_TA option present%s",
++			  dhcpv6_type_names[packet->dhcpv6_msg_type],
++			  piaddr(packet->client_addr), client_id_str);
++		goto exit;
++	}
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_IA_PD);
++	if (oc != NULL) {
++		log_debug("Discarding %s from %s; "
++			  "IA_PD option present%s",
++			  dhcpv6_type_names[packet->dhcpv6_msg_type],
++			  piaddr(packet->client_addr), client_id_str);
++		goto exit;
++	}
++
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_SERVERID);
++	if (oc != NULL) {
++		if (!evaluate_option_cache(server_id, packet, NULL, NULL,
++					   packet->options, NULL,
++					   &global_scope, oc, MDL)) {
++			log_error("Error processing %s from %s; "
++				  "unable to evaluate Server Identifier%s",
++				  dhcpv6_type_names[packet->dhcpv6_msg_type],
++				  piaddr(packet->client_addr), client_id_str);
++			goto exit;
++		}
++		if ((server_duid.len != server_id->len) ||
++		    (memcmp(server_duid.data, server_id->data,
++		    	    server_duid.len) != 0)) {
++			log_debug("Discarding %s from %s; "
++				  "not our server identifier "
++				  "(SERVERID %s, server DUID %s)%s",
++				  dhcpv6_type_names[packet->dhcpv6_msg_type],
++				  piaddr(packet->client_addr),
++				  print_hex_1(server_id->len,
++				  	      server_id->data, 60),
++				  print_hex_2(server_duid.len,
++				  	      server_duid.data, 60),
++				  client_id_str);
++			goto exit;
++		}
++	}
++
++	/* looks good */
++	ret_val = 1;
++
++exit:
++	if (!ret_val) {
++		if (server_id->len > 0) {
++			data_string_forget(server_id, MDL);
++		}
++	}
++	return ret_val;
++}
++
++/* 
++ * Options that we want to send, in addition to what was requested
++ * via the ORO.
++ */
++static const int required_opts[] = {
++	D6O_CLIENTID,
++	D6O_SERVERID,
++	D6O_STATUS_CODE,
++	D6O_PREFERENCE,
++	0
++};
++static const int required_opts_NAA[] = {
++	D6O_CLIENTID,
++	D6O_SERVERID,
++	D6O_STATUS_CODE,
++	0
++};
++static const int required_opts_solicit[] = {
++	D6O_CLIENTID,
++	D6O_SERVERID,
++	D6O_IA_NA,
++	D6O_IA_TA,
++	D6O_IA_PD,
++	D6O_RAPID_COMMIT,
++	D6O_STATUS_CODE,
++	D6O_RECONF_ACCEPT,
++	D6O_PREFERENCE,
++	0
++};
++static const int required_opts_agent[] = {
++	D6O_INTERFACE_ID,
++	D6O_RELAY_MSG,
++	0
++};
++static const int required_opts_IA[] = {
++	D6O_IAADDR,
++	D6O_STATUS_CODE,
++	0
++};
++static const int required_opts_IA_PD[] = {
++	D6O_IAPREFIX,
++	D6O_STATUS_CODE,
++	0
++};
++static const int required_opts_STATUS_CODE[] = {
++	D6O_STATUS_CODE,
++	0
++};
++
++/*
++ * Extracts from packet contents an IA_* option, storing the IA structure
++ * in its entirety in enc_opt_data, and storing any decoded DHCPv6 options
++ * in enc_opt_state for later lookup and evaluation.  The 'offset' indicates
++ * where in the IA_* the DHCPv6 options commence.
++ */
++static int
++get_encapsulated_IA_state(struct option_state **enc_opt_state,
++			  struct data_string *enc_opt_data,
++			  struct packet *packet,
++			  struct option_cache *oc,
++			  int offset)
++{
++	/* 
++	 * Get the raw data for the encapsulated options.
++	 */
++	memset(enc_opt_data, 0, sizeof(*enc_opt_data));
++	if (!evaluate_option_cache(enc_opt_data, packet,
++				   NULL, NULL, packet->options, NULL,
++				   &global_scope, oc, MDL)) {
++		log_error("get_encapsulated_IA_state: "
++			  "error evaluating raw option.");
++		return 0;
++	}
++	if (enc_opt_data->len < offset) {
++		log_error("get_encapsulated_IA_state: raw option too small.");
++		data_string_forget(enc_opt_data, MDL);
++		return 0;
++	}
++
++	/*
++	 * Now create the option state structure, and pass it to the 
++	 * function that parses options.
++	 */
++	*enc_opt_state = NULL;
++	if (!option_state_allocate(enc_opt_state, MDL)) {
++		log_error("get_encapsulated_IA_state: no memory for options.");
++		data_string_forget(enc_opt_data, MDL);
++		return 0;
++	}
++	if (!parse_option_buffer(*enc_opt_state,
++				 enc_opt_data->data + offset, 
++				 enc_opt_data->len - offset,
++				 &dhcpv6_universe)) {
++		log_error("get_encapsulated_IA_state: error parsing options.");
++		option_state_dereference(enc_opt_state, MDL);
++		data_string_forget(enc_opt_data, MDL);
++		return 0;
++	}
++
++	return 1;
++}
++
++static int
++set_status_code(u_int16_t status_code, const char *status_message,
++		struct option_state *opt_state)
++{
++	struct data_string d;
++	int ret_val;
++
++	memset(&d, 0, sizeof(d));
++	d.len = sizeof(status_code) + strlen(status_message);
++	if (!buffer_allocate(&d.buffer, d.len, MDL)) {
++		log_fatal("set_status_code: no memory for status code.");
++	}
++	d.data = d.buffer->data;
++	putUShort(d.buffer->data, status_code);
++	memcpy(d.buffer->data + sizeof(status_code), 
++	       status_message, d.len - sizeof(status_code));
++	if (!save_option_buffer(&dhcpv6_universe, opt_state, 
++				d.buffer, (unsigned char *)d.data, d.len, 
++				D6O_STATUS_CODE, 0)) {
++		log_error("set_status_code: error saving status code.");
++		ret_val = 0;
++	} else {
++		ret_val = 1;
++	}
++	data_string_forget(&d, MDL);
++	return ret_val;
++}
++
++/*
++ * We have a set of operations we do to set up the reply packet, which
++ * is the same for many message types.
++ */
++static int
++start_reply(struct packet *packet,
++	    const struct data_string *client_id, 
++	    const struct data_string *server_id,
++	    struct option_state **opt_state,
++	    struct dhcpv6_packet *reply)
++{
++	struct option_cache *oc;
++	const unsigned char *server_id_data;
++	int server_id_len;
++
++	/*
++	 * Build our option state for reply.
++	 */
++	*opt_state = NULL;
++	if (!option_state_allocate(opt_state, MDL)) {
++		log_error("start_reply: no memory for option_state.");
++		return 0;
++	}
++	execute_statements_in_scope(NULL, packet, NULL, NULL,
++				    packet->options, *opt_state,
++				    &global_scope, root_group, NULL);
++
++	/*
++	 * A small bit of special handling for Solicit messages.
++	 *
++	 * We could move the logic into a flag, but for now just check
++	 * explicitly.
++	 */
++	if (packet->dhcpv6_msg_type == DHCPV6_SOLICIT) {
++		reply->msg_type = DHCPV6_ADVERTISE;
++
++		/*
++		 * If:
++		 * - this message type supports rapid commit (Solicit), and
++		 * - the server is configured to supply a rapid commit, and
++		 * - the client requests a rapid commit,
++		 * Then we add a rapid commit option, and send Reply (instead
++		 * of an Advertise).
++		 */
++		oc = lookup_option(&dhcpv6_universe,
++				   *opt_state, D6O_RAPID_COMMIT);
++		if (oc != NULL) {
++			oc = lookup_option(&dhcpv6_universe,
++					   packet->options, D6O_RAPID_COMMIT);
++			if (oc != NULL) {
++				/* Rapid-commit in action. */
++				reply->msg_type = DHCPV6_REPLY;
++			} else {
++				/* Don't want a rapid-commit in advertise. */
++				delete_option(&dhcpv6_universe,
++					      *opt_state, D6O_RAPID_COMMIT);
++			}
++		}
++	} else {
++		reply->msg_type = DHCPV6_REPLY;
++		/* Delete the rapid-commit from the sent options. */
++		oc = lookup_option(&dhcpv6_universe,
++				   *opt_state, D6O_RAPID_COMMIT);
++		if (oc != NULL) {
++			delete_option(&dhcpv6_universe,
++				      *opt_state, D6O_RAPID_COMMIT);
++		}
++	}
++
++	/* 
++	 * Use the client's transaction identifier for the reply.
++	 */
++	memcpy(reply->transaction_id, packet->dhcpv6_transaction_id, 
++	       sizeof(reply->transaction_id));
++
++	/* 
++	 * RFC 3315, section 18.2 says we need server identifier and
++	 * client identifier.
++	 *
++	 * If the server ID is defined via the configuration file, then
++	 * it will already be present in the option state at this point, 
++	 * so we don't need to set it.
++	 *
++	 * If we have a server ID passed in from the caller, 
++	 * use that, otherwise use the global DUID.
++	 */
++	oc = lookup_option(&dhcpv6_universe, *opt_state, D6O_SERVERID);
++	if (oc == NULL) {
++		if (server_id == NULL) {
++			server_id_data = server_duid.data;
++			server_id_len = server_duid.len;
++		} else {
++			server_id_data = server_id->data;
++			server_id_len = server_id->len;
++		}
++		if (!save_option_buffer(&dhcpv6_universe, *opt_state, 
++					NULL, (unsigned char *)server_id_data,
++					server_id_len, D6O_SERVERID, 0)) {
++				log_error("start_reply: "
++					  "error saving server identifier.");
++				return 0;
++		}
++	}
++
++	if (client_id->buffer != NULL) {
++		if (!save_option_buffer(&dhcpv6_universe, *opt_state, 
++					client_id->buffer, 
++					(unsigned char *)client_id->data, 
++					client_id->len, 
++					D6O_CLIENTID, 0)) {
++			log_error("start_reply: error saving "
++				  "client identifier.");
++			return 0;
++		}
++	}
++
++	/*
++	 * If the client accepts reconfiguration, let it know that we
++	 * will send them.
++	 *
++	 * Note: we don't actually do this yet, but DOCSIS requires we
++	 *       claim to.
++	 */
++	oc = lookup_option(&dhcpv6_universe, packet->options,
++			   D6O_RECONF_ACCEPT);
++	if (oc != NULL) {
++		if (!save_option_buffer(&dhcpv6_universe, *opt_state,
++					NULL, (unsigned char *)"", 0, 
++					D6O_RECONF_ACCEPT, 0)) {
++			log_error("start_reply: "
++				  "error saving RECONF_ACCEPT option.");
++			option_state_dereference(opt_state, MDL);
++			return 0;
++		}
++	}
++
++	return 1;
++}
++
++/*
++ * Try to get the IPv6 address the client asked for from the
++ * pool.
++ *
++ * addr is the result (should be a pointer to NULL on entry)
++ * pool is the pool to search in
++ * requested_addr is the address the client wants
++ */
++static isc_result_t
++try_client_v6_address(struct iasubopt **addr,
++		      struct ipv6_pool *pool,
++		      const struct data_string *requested_addr)
++{
++	struct in6_addr tmp_addr;
++	isc_result_t result;
++
++	if (requested_addr->len < sizeof(tmp_addr)) {
++		return ISC_R_INVALIDARG;
++	}
++	memcpy(&tmp_addr, requested_addr->data, sizeof(tmp_addr));
++	if (IN6_IS_ADDR_UNSPECIFIED(&tmp_addr)) {
++		return ISC_R_FAILURE;
++	}
++
++	/*
++	 * The address is not covered by this (or possibly any) dynamic
++	 * range.
++	 */
++	if (!ipv6_in_pool(&tmp_addr, pool)) {
++		return ISC_R_ADDRNOTAVAIL;
++	}
++
++	if (lease6_exists(pool, &tmp_addr)) {
++		return ISC_R_ADDRINUSE;
++	}
++
++	result = iasubopt_allocate(addr, MDL);
++	if (result != ISC_R_SUCCESS) {
++		return result;
++	}
++	(*addr)->addr = tmp_addr;
++	(*addr)->plen = 0;
++
++	/* Default is soft binding for 2 minutes. */
++	result = add_lease6(pool, *addr, cur_time + 120);
++	if (result != ISC_R_SUCCESS) {
++		iasubopt_dereference(addr, MDL);
++	}
++	return result;
++}
++
++/*
++ * Get an IPv6 address for the client.
++ *
++ * addr is the result (should be a pointer to NULL on entry)
++ * packet is the information about the packet from the client
++ * requested_iaaddr is a hint from the client
++ * client_id is the DUID for the client
++ */
++static isc_result_t 
++pick_v6_address(struct iasubopt **addr, struct shared_network *shared_network,
++		const struct data_string *client_id)
++{
++	struct ipv6_pool *p;
++	int i;
++	int start_pool;
++	unsigned int attempts;
++	char tmp_buf[INET6_ADDRSTRLEN];
++
++	/*
++	 * No address pools, we're done.
++	 */
++	if (shared_network->ipv6_pools == NULL) {
++		log_debug("Unable to pick client address: "
++			  "no IPv6 pools on this shared network");
++		return ISC_R_NORESOURCES;
++	}
++	for (i = 0;; i++) {
++		p = shared_network->ipv6_pools[i];
++		if (p == NULL) {
++			log_debug("Unable to pick client address: "
++				  "no IPv6 address pools "
++				  "on this shared network");
++			return ISC_R_NORESOURCES;
++		}
++		if (p->pool_type == D6O_IA_NA) {
++			break;
++		}
++	}
++
++	/*
++	 * Otherwise try to get a lease from the first subnet possible.
++	 *
++	 * We start looking at the last pool we allocated from, unless
++	 * it had a collision trying to allocate an address. This will
++	 * tend to move us into less-filled pools.
++	 */
++	start_pool = shared_network->last_ipv6_pool;
++	i = start_pool;
++	do {
++
++		p = shared_network->ipv6_pools[i];
++		if ((p->pool_type == D6O_IA_NA) &&
++		    (create_lease6(p, addr, &attempts, client_id,
++				   cur_time + 120) == ISC_R_SUCCESS)) {
++			/*
++			 * Record the pool used (or next one if there 
++			 * was a collision).
++			 */
++			if (attempts > 1) {
++				i++;
++				if (shared_network->ipv6_pools[i] == NULL) {
++					i = 0;
++				}
++			}
++			shared_network->last_ipv6_pool = i;
++
++			log_debug("Picking pool address %s",
++				  inet_ntop(AF_INET6, &((*addr)->addr),
++				  	    tmp_buf, sizeof(tmp_buf)));
++			return ISC_R_SUCCESS;
++		}
++
++		i++;
++		if (shared_network->ipv6_pools[i] == NULL) {
++			i = 0;
++		}
++	} while (i != start_pool);
++
++	/*
++	 * If we failed to pick an IPv6 address from any of the subnets.
++	 * Presumably that means we have no addresses for the client.
++	 */
++	log_debug("Unable to pick client address: no addresses available");
++	return ISC_R_NORESOURCES;
++}
++
++/*
++ * Try to get the IPv6 prefix the client asked for from the
++ * prefix pool.
++ *
++ * pref is the result (should be a pointer to NULL on entry)
++ * pool is the prefix pool to search in
++ * requested_pref is the address the client wants
++ */
++static isc_result_t
++try_client_v6_prefix(struct iasubopt **pref,
++		     struct ipv6_pool *pool,
++		     const struct data_string *requested_pref)
++{
++	u_int8_t tmp_plen;
++	struct in6_addr tmp_pref;
++	struct iaddr ia;
++	isc_result_t result;
++
++	if (requested_pref->len < sizeof(tmp_plen) + sizeof(tmp_pref)) {
++		return ISC_R_INVALIDARG;
++	}
++	tmp_plen = (int) requested_pref->data[0];
++	if ((tmp_plen < 3) || (tmp_plen > 128)) {
++		return ISC_R_FAILURE;
++	}
++	memcpy(&tmp_pref, requested_pref->data + 1, sizeof(tmp_pref));
++	if (IN6_IS_ADDR_UNSPECIFIED(&tmp_pref)) {
++		return ISC_R_FAILURE;
++	}
++	ia.len = 16;
++	memcpy(&ia.iabuf, &tmp_pref, 16);
++	if (!is_cidr_mask_valid(&ia, (int) tmp_plen)) {
++		return ISC_R_FAILURE;
++	}
++
++	if (((int)tmp_plen != pool->units) ||
++	    !ipv6_in_pool(&tmp_pref, pool)) {
++		return ISC_R_FAILURE;
++	}
++
++	if (prefix6_exists(pool, &tmp_pref, tmp_plen)) {
++		return ISC_R_ADDRINUSE;
++	}
++
++	result = iasubopt_allocate(pref, MDL);
++	if (result != ISC_R_SUCCESS) {
++		return result;
++	}
++	(*pref)->addr = tmp_pref;
++	(*pref)->plen = tmp_plen;
++
++	/* Default is soft binding for 2 minutes. */
++	result = add_lease6(pool, *pref, cur_time + 120);
++	if (result != ISC_R_SUCCESS) {
++		iasubopt_dereference(pref, MDL);
++	}
++	return result;
++}
++
++/*
++ * Get an IPv6 prefix for the client.
++ *
++ * pref is the result (should be a pointer to NULL on entry)
++ * packet is the information about the packet from the client
++ * requested_iaprefix is a hint from the client
++ * plen is -1 or the requested prefix length
++ * client_id is the DUID for the client
++ */
++static isc_result_t 
++pick_v6_prefix(struct iasubopt **pref, int plen,
++	       struct shared_network *shared_network,
++	       const struct data_string *client_id)
++{
++	struct ipv6_pool *p;
++	int i;
++	unsigned int attempts;
++	char tmp_buf[INET6_ADDRSTRLEN];
++
++	/*
++	 * No prefix pools, we're done.
++	 */
++	if (shared_network->ipv6_pools == NULL) {
++		log_debug("Unable to pick client prefix: "
++			  "no IPv6 pools on this shared network");
++		return ISC_R_NORESOURCES;
++	}
++	for (i = 0;; i++) {
++		p = shared_network->ipv6_pools[i];
++		if (p == NULL) {
++			log_debug("Unable to pick client prefix: "
++				  "no IPv6 prefix pools "
++				  "on this shared network");
++			return ISC_R_NORESOURCES;
++		}
++		if (p->pool_type == D6O_IA_PD) {
++			break;
++		}
++	}
++
++	/*
++	 * Otherwise try to get a prefix.
++	 */
++	for (i = 0;; i++) {
++		p = shared_network->ipv6_pools[i];
++		if (p == NULL) {
++			break;
++		}
++		if (p->pool_type != D6O_IA_PD) {
++			continue;
++		}
++
++		/*
++		 * Try only pools with the requested prefix length if any.
++		 */
++		if ((plen >= 0) && (p->units != plen)) {
++			continue;
++		}
++
++		if (create_prefix6(p, pref, &attempts, client_id,
++				   cur_time + 120) == ISC_R_SUCCESS) {
++			log_debug("Picking pool prefix %s/%u",
++				  inet_ntop(AF_INET6, &((*pref)->addr),
++				  	    tmp_buf, sizeof(tmp_buf)),
++				  (unsigned) (*pref)->plen);
++			return ISC_R_SUCCESS;
++		}
++	}
++
++	/*
++	 * If we failed to pick an IPv6 prefix
++	 * Presumably that means we have no prefixes for the client.
++	 */
++	log_debug("Unable to pick client prefix: no prefixes available");
++	return ISC_R_NORESOURCES;
++}
++
++/*
++ * lease_to_client() is called from several messages to construct a
++ * reply that contains all that we know about the client's correct lease
++ * (or projected lease).
++ *
++ * Solicit - "Soft" binding, ignore unknown addresses or bindings, just
++ *	     send what we "may" give them on a request.
++ *
++ * Request - "Hard" binding, but ignore supplied addresses (just provide what
++ *	     the client should really use).
++ *
++ * Renew   - "Hard" binding, but client-supplied addresses are 'real'.  Error
++ * Rebind    out any "wrong" addresses the client sends.  This means we send
++ *	     an empty IA_NA with a status code of NoBinding or NotOnLink or
++ *	     possibly send the address with zeroed lifetimes.
++ *
++ * Information-Request - No binding.
++ *
++ * The basic structure is to traverse the client-supplied data first, and
++ * validate and echo back any contents that can be.  If the client-supplied
++ * data does not error out (on renew/rebind as above), but we did not send
++ * any addresses, attempt to allocate one.
++ */
++/* TODO: look at client hints for lease times */
++static void
++lease_to_client(struct data_string *reply_ret,
++		struct packet *packet, 
++		const struct data_string *client_id,
++		const struct data_string *server_id)
++{
++	static struct reply_state reply;
++	struct option_cache *oc;
++	struct data_string packet_oro;
++	isc_boolean_t no_resources_avail;
++
++	/* Locate the client.  */
++	if (shared_network_from_packet6(&reply.shared,
++					packet) != ISC_R_SUCCESS)
++		goto exit;
++
++	/* 
++	 * Initialize the reply.
++	 */
++	packet_reference(&reply.packet, packet, MDL);
++	data_string_copy(&reply.client_id, client_id, MDL);
++
++	if (!start_reply(packet, client_id, server_id, &reply.opt_state,
++			 &reply.buf.reply))
++		goto exit;
++
++	/* Set the write cursor to just past the reply header. */
++	reply.cursor = REPLY_OPTIONS_INDEX;
++
++	/*
++	 * Get the ORO from the packet, if any.
++	 */
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_ORO);
++	memset(&packet_oro, 0, sizeof(packet_oro));
++	if (oc != NULL) {
++		if (!evaluate_option_cache(&packet_oro, packet, 
++					   NULL, NULL, 
++					   packet->options, NULL,
++					   &global_scope, oc, MDL)) {
++			log_error("lease_to_client: error evaluating ORO.");
++			goto exit;
++		}
++	}
++
++	/* 
++	 * Find a host record that matches from the packet, if any, and is
++	 * valid for the shared network the client is on.
++	 */
++	if (find_hosts_by_option(&reply.host, packet, packet->options, MDL)) {
++		seek_shared_host(&reply.host, reply.shared);
++	}
++
++	if ((reply.host == NULL) &&
++	    find_hosts_by_uid(&reply.host, client_id->data, client_id->len,
++			      MDL)) {
++		seek_shared_host(&reply.host, reply.shared);
++	}
++
++	/* Process the client supplied IA's onto the reply buffer. */
++	reply.ia_count = 0;
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_IA_NA);
++	no_resources_avail = ISC_FALSE;
++	for (; oc != NULL ; oc = oc->next) {
++		isc_result_t status;
++
++		/* Start counting resources (addresses) offered. */
++		reply.client_resources = 0;
++		reply.resources_included = ISC_FALSE;
++
++		status = reply_process_ia_na(&reply, oc);
++
++		/*
++		 * We continue to try other IA's whether we can address
++		 * this one or not.  Any other result is an immediate fail.
++		 */
++		if ((status != ISC_R_SUCCESS) &&
++		    (status != ISC_R_NORESOURCES))
++			goto exit;
++
++		/*
++		 * If any address cannot be given to any IA, then set the
++		 * NoAddrsAvail status code.
++		 */
++		if (reply.client_resources == 0)
++			no_resources_avail = ISC_TRUE;
++	}
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_IA_TA);
++	for (; oc != NULL ; oc = oc->next) {
++		isc_result_t status;
++
++		/* Start counting resources (addresses) offered. */
++		reply.client_resources = 0;
++		reply.resources_included = ISC_FALSE;
++
++		status = reply_process_ia_ta(&reply, oc);
++
++		/*
++		 * We continue to try other IA's whether we can address
++		 * this one or not.  Any other result is an immediate fail.
++		 */
++		if ((status != ISC_R_SUCCESS) &&
++		    (status != ISC_R_NORESOURCES))
++			goto exit;
++
++		/*
++		 * If any address cannot be given to any IA, then set the
++		 * NoAddrsAvail status code.
++		 */
++		if (reply.client_resources == 0)
++			no_resources_avail = ISC_TRUE;
++	}
++
++	/* Same for IA_PD's. */
++	reply.pd_count = 0;
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_IA_PD);
++	for (; oc != NULL ; oc = oc->next) {
++		isc_result_t status;
++
++		/* Start counting resources (prefixes) offered. */
++		reply.client_resources = 0;
++		reply.resources_included = ISC_FALSE;
++
++		status = reply_process_ia_pd(&reply, oc);
++
++		/*
++		 * We continue to try other IA_PD's whether we can address
++		 * this one or not.  Any other result is an immediate fail.
++		 */
++		if ((status != ISC_R_SUCCESS) &&
++		    (status != ISC_R_NORESOURCES))
++			goto exit;
++
++		/*
++		 * If any prefix cannot be given to any IA_PD, then
++		 * set the NoPrefixAvail status code.
++		 */
++		if (reply.client_resources == 0)
++			no_resources_avail = ISC_TRUE;
++	}
++
++	/*
++	 * Make no reply if we gave no resources and is not
++	 * for Information-Request.
++	 */
++	if ((reply.ia_count == 0) && (reply.pd_count == 0)) {
++		if (reply.packet->dhcpv6_msg_type !=
++					    DHCPV6_INFORMATION_REQUEST)
++			goto exit;
++
++		/*
++		 * Because we only execute statements on a per-IA basis,
++		 * we need to execute statements in any non-IA reply to
++		 * source configuration.
++		 */
++		execute_statements_in_scope(NULL, reply.packet, NULL, NULL,
++					    reply.packet->options,
++					    reply.opt_state, &global_scope,
++					    reply.shared->group, root_group);
++
++		/* Bring in any configuration from a host record. */
++		if (reply.host != NULL)
++			execute_statements_in_scope(NULL, reply.packet, NULL,
++						    NULL, reply.packet->options,
++						    reply.opt_state,
++						    &global_scope,
++						    reply.host->group,
++						    reply.shared->group);
++	}
++
++	/*
++	 * RFC3315 section 17.2.2 (Solicit):
++	 *
++	 * If the server will not assign any addresses to any IAs in a
++	 * subsequent Request from the client, the server MUST send an
++	 * Advertise message to the client that includes only a Status
++	 * Code option with code NoAddrsAvail and a status message for
++	 * the user, a Server Identifier option with the server's DUID,
++	 * and a Client Identifier option with the client's DUID.
++	 *
++	 * Section 18.2.1 (Request):
++	 *
++	 * If the server cannot assign any addresses to an IA in the
++	 * message from the client, the server MUST include the IA in
++	 * the Reply message with no addresses in the IA and a Status
++	 * Code option in the IA containing status code NoAddrsAvail.
++	 *
++	 * Section 18.1.8 (Client Behavior):
++	 *
++	 * Leave unchanged any information about addresses the client has
++	 * recorded in the IA but that were not included in the IA from
++	 * the server.
++	 * Sends a Renew/Rebind if the IA is not in the Reply message.
++	 */
++	if (no_resources_avail && (reply.ia_count != 0) &&
++	    (reply.packet->dhcpv6_msg_type == DHCPV6_SOLICIT))
++	{
++		/* Set the NoAddrsAvail status code. */
++		if (!set_status_code(STATUS_NoAddrsAvail,
++				     "No addresses available for this "
++				     "interface.", reply.opt_state)) {
++			log_error("lease_to_client: Unable to set "
++				  "NoAddrsAvail status code.");
++			goto exit;
++		}
++
++		/* Rewind the cursor to the start. */
++		reply.cursor = REPLY_OPTIONS_INDEX;
++
++		/*
++		 * Produce an advertise that includes only:
++		 *
++		 * Status code.
++		 * Server DUID.
++		 * Client DUID.
++		 */
++		reply.buf.reply.msg_type = DHCPV6_ADVERTISE;
++		reply.cursor += store_options6((char *)reply.buf.data +
++							reply.cursor,
++					       sizeof(reply.buf) -
++					       		reply.cursor,
++					       reply.opt_state, reply.packet,
++					       required_opts_NAA,
++					       NULL);
++	} else if (no_resources_avail && (reply.ia_count == 0) &&
++		   (reply.packet->dhcpv6_msg_type == DHCPV6_SOLICIT))
++	{
++		/* Set the NoPrefixAvail status code. */
++		if (!set_status_code(STATUS_NoPrefixAvail,
++				     "No prefixes available for this "
++				     "interface.", reply.opt_state)) {
++			log_error("lease_to_client: Unable to set "
++				  "NoPrefixAvail status code.");
++			goto exit;
++		}
++
++		/* Rewind the cursor to the start. */
++		reply.cursor = REPLY_OPTIONS_INDEX;
++
++		/*
++		 * Produce an advertise that includes only:
++		 *
++		 * Status code.
++		 * Server DUID.
++		 * Client DUID.
++		 */
++		reply.buf.reply.msg_type = DHCPV6_ADVERTISE;
++		reply.cursor += store_options6((char *)reply.buf.data +
++							reply.cursor,
++					       sizeof(reply.buf) -
++					       		reply.cursor,
++					       reply.opt_state, reply.packet,
++					       required_opts_NAA,
++					       NULL);
++	} else {
++		/*
++		 * Having stored the client's IA's, store any options that
++		 * will fit in the remaining space.
++		 */
++		reply.cursor += store_options6((char *)reply.buf.data +
++							reply.cursor,
++					       sizeof(reply.buf) -
++							reply.cursor,
++					       reply.opt_state, reply.packet,
++					       required_opts_solicit,
++					       &packet_oro);
++	}
++
++	/* Return our reply to the caller. */
++	reply_ret->len = reply.cursor;
++	reply_ret->buffer = NULL;
++	if (!buffer_allocate(&reply_ret->buffer, reply.cursor, MDL)) {
++		log_fatal("No memory to store Reply.");
++	}
++	memcpy(reply_ret->buffer->data, reply.buf.data, reply.cursor);
++	reply_ret->data = reply_ret->buffer->data;
++
++      exit:
++	/* Cleanup. */
++	if (reply.shared != NULL)
++		shared_network_dereference(&reply.shared, MDL);
++	if (reply.host != NULL)
++		host_dereference(&reply.host, MDL);
++	if (reply.opt_state != NULL)
++		option_state_dereference(&reply.opt_state, MDL);
++	if (reply.packet != NULL)
++		packet_dereference(&reply.packet, MDL);
++	if (reply.client_id.data != NULL)
++		data_string_forget(&reply.client_id, MDL);
++	reply.renew = reply.rebind = reply.prefer = reply.valid = 0;
++	reply.cursor = 0;
++}
++
++/* Process a client-supplied IA_NA.  This may append options to the tail of
++ * the reply packet being built in the reply_state structure.
++ */
++static isc_result_t
++reply_process_ia_na(struct reply_state *reply, struct option_cache *ia) {
++	isc_result_t status = ISC_R_SUCCESS;
++	u_int32_t iaid;
++	unsigned ia_cursor;
++	struct option_state *packet_ia;
++	struct option_cache *oc;
++	struct data_string ia_data, data;
++
++	/* Initialize values that will get cleaned up on return. */
++	packet_ia = NULL;
++	memset(&ia_data, 0, sizeof(ia_data));
++	memset(&data, 0, sizeof(data));
++	/* 
++	 * Note that find_client_address() may set reply->lease. 
++	 */
++
++	/* Make sure there is at least room for the header. */
++	if ((reply->cursor + IA_NA_OFFSET + 4) > sizeof(reply->buf)) {
++		log_error("reply_process_ia_na: Reply too long for IA.");
++		return ISC_R_NOSPACE;
++	}
++
++
++	/* Fetch the IA_NA contents. */
++	if (!get_encapsulated_IA_state(&packet_ia, &ia_data, reply->packet,
++				       ia, IA_NA_OFFSET)) {
++		log_error("reply_process_ia_na: error evaluating ia");
++		status = ISC_R_FAILURE;
++		goto cleanup;
++	}
++
++	/* Extract IA_NA header contents. */
++	iaid = getULong(ia_data.data);
++	reply->renew = getULong(ia_data.data + 4);
++	reply->rebind = getULong(ia_data.data + 8);
++
++	/* Create an IA_NA structure. */
++	if (ia_allocate(&reply->ia, iaid, (char *)reply->client_id.data, 
++			reply->client_id.len, MDL) != ISC_R_SUCCESS) {
++		log_error("reply_process_ia_na: no memory for ia.");
++		status = ISC_R_NOMEMORY;
++		goto cleanup;
++	}
++	reply->ia->ia_type = D6O_IA_NA;
++
++	/* Cache pre-existing IA, if any. */
++	ia_hash_lookup(&reply->old_ia, ia_na_active,
++		       (unsigned char *)reply->ia->iaid_duid.data,
++		       reply->ia->iaid_duid.len, MDL);
++
++	/*
++	 * Create an option cache to carry the IA_NA option contents, and
++	 * execute any user-supplied values into it.
++	 */
++	if (!option_state_allocate(&reply->reply_ia, MDL)) {
++		status = ISC_R_NOMEMORY;
++		goto cleanup;
++	}
++
++	/* Check & cache the fixed host record. */
++	if ((reply->host != NULL) && (reply->host->fixed_addr != NULL)) {
++		struct iaddr tmp_addr;
++
++		if (!evaluate_option_cache(&reply->fixed, NULL, NULL, NULL,
++					   NULL, NULL, &global_scope,
++					   reply->host->fixed_addr, MDL)) {
++			log_error("reply_process_ia_na: unable to evaluate "
++				  "fixed address.");
++			status = ISC_R_FAILURE;
++			goto cleanup;
++		}
++
++		if (reply->fixed.len < 16) {
++			log_error("reply_process_ia_na: invalid fixed address.");
++			status = ISC_R_INVALIDARG;
++			goto cleanup;
++		}
++
++		/* Find the static lease's subnet. */
++		tmp_addr.len = 16;
++		memcpy(tmp_addr.iabuf, reply->fixed.data, 16);
++
++		if (find_grouped_subnet(&reply->subnet, reply->shared,
++					tmp_addr, MDL) == 0)
++			log_fatal("Impossible condition at %s:%d.", MDL);
++
++		reply->static_lease = ISC_TRUE;
++	} else
++		reply->static_lease = ISC_FALSE;
++
++	/*
++	 * Save the cursor position at the start of the IA, so we can
++	 * set length and adjust t1/t2 values later.  We write a temporary
++	 * header out now just in case we decide to adjust the packet
++	 * within sub-process functions.
++	 */
++	ia_cursor = reply->cursor;
++
++	/* Initialize the IA_NA header.  First the code. */
++	putUShort(reply->buf.data + reply->cursor, (unsigned)D6O_IA_NA);
++	reply->cursor += 2;
++
++	/* Then option length. */
++	putUShort(reply->buf.data + reply->cursor, 0x0Cu);
++	reply->cursor += 2;
++
++	/* Then IA_NA header contents; IAID. */
++	putULong(reply->buf.data + reply->cursor, iaid);
++	reply->cursor += 4;
++
++	/* We store the client's t1 for now, and may over-ride it later. */
++	putULong(reply->buf.data + reply->cursor, reply->renew);
++	reply->cursor += 4;
++
++	/* We store the client's t2 for now, and may over-ride it later. */
++	putULong(reply->buf.data + reply->cursor, reply->rebind);
++	reply->cursor += 4;
++
++	/* 
++	 * For each address in this IA_NA, decide what to do about it.
++	 *
++	 * Guidelines:
++	 *
++	 * The client leaves unchanged any infomation about addresses
++	 * it has recorded but are not included ("cancel/break" below).
++	 * A not included IA ("cleanup" below) could give a Renew/Rebind.
++	 */
++	oc = lookup_option(&dhcpv6_universe, packet_ia, D6O_IAADDR);
++	reply->valid = reply->prefer = 0xffffffff;
++	reply->client_valid = reply->client_prefer = 0;
++	for (; oc != NULL ; oc = oc->next) {
++		status = reply_process_addr(reply, oc);
++
++		/*
++		 * Canceled means we did not allocate addresses to the
++		 * client, but we're "done" with this IA - we set a status
++		 * code.  So transmit this reply, e.g., move on to the next
++		 * IA.
++		 */
++		if (status == ISC_R_CANCELED)
++			break;
++
++		if ((status != ISC_R_SUCCESS) &&
++		    (status != ISC_R_ADDRINUSE) &&
++		    (status != ISC_R_ADDRNOTAVAIL))
++			goto cleanup;
++	}
++
++	reply->ia_count++;
++
++	/*
++	 * If we fell through the above and never gave the client
++	 * an address, give it one now.
++	 */
++	if ((status != ISC_R_CANCELED) && (reply->client_resources == 0)) {
++		status = find_client_address(reply);
++
++		if (status == ISC_R_NORESOURCES) {
++			switch (reply->packet->dhcpv6_msg_type) {
++			      case DHCPV6_SOLICIT:
++				/*
++				 * No address for any IA is handled
++				 * by the caller.
++				 */
++				/* FALL THROUGH */
++
++			      case DHCPV6_REQUEST:
++				/* Section 18.2.1 (Request):
++				 *
++				 * If the server cannot assign any addresses to
++				 * an IA in the message from the client, the
++				 * server MUST include the IA in the Reply
++				 * message with no addresses in the IA and a
++				 * Status Code option in the IA containing
++				 * status code NoAddrsAvail.
++				 */
++				option_state_dereference(&reply->reply_ia, MDL);
++				if (!option_state_allocate(&reply->reply_ia,
++							   MDL))
++				{
++					log_error("reply_process_ia_na: No "
++						  "memory for option state "
++						  "wipe.");
++					status = ISC_R_NOMEMORY;
++					goto cleanup;
++				}
++
++				if (!set_status_code(STATUS_NoAddrsAvail,
++						     "No addresses available "
++						     "for this interface.",
++						      reply->reply_ia)) {
++					log_error("reply_process_ia_na: Unable "
++						  "to set NoAddrsAvail status "
++						  "code.");
++					status = ISC_R_FAILURE;
++					goto cleanup;
++				}
++
++				status = ISC_R_SUCCESS;
++				break;
++
++			      default:
++				/*
++				 * RFC 3315 does not tell us to emit a status
++				 * code in this condition, or anything else.
++				 *
++				 * If we included non-allocated addresses
++				 * (zeroed lifetimes) in an IA, then the client
++				 * will deconfigure them.
++				 *
++				 * So we want to include the IA even if we
++				 * can't give it a new address if it includes
++				 * zeroed lifetime addresses.
++				 *
++				 * We don't want to include the IA if we
++				 * provide zero addresses including zeroed
++				 * lifetimes.
++				 */
++				if (reply->resources_included)
++					status = ISC_R_SUCCESS;
++				else
++					goto cleanup;
++				break;
++			}
++		}
++
++		if (status != ISC_R_SUCCESS)
++			goto cleanup;
++	}
++
++	reply->cursor += store_options6((char *)reply->buf.data + reply->cursor,
++					sizeof(reply->buf) - reply->cursor,
++					reply->reply_ia, reply->packet,
++					required_opts_IA, NULL);
++
++	/* Reset the length of this IA to match what was just written. */
++	putUShort(reply->buf.data + ia_cursor + 2,
++		  reply->cursor - (ia_cursor + 4));
++
++	/*
++	 * T1/T2 time selection is kind of weird.  We actually use DHCP
++	 * (v4) scoped options as handy existing places where these might
++	 * be configured by an administrator.  A value of zero tells the
++	 * client it may choose its own renewal time.
++	 */
++	reply->renew = 0;
++	oc = lookup_option(&dhcp_universe, reply->opt_state,
++			   DHO_DHCP_RENEWAL_TIME);
++	if (oc != NULL) {
++		if (!evaluate_option_cache(&data, reply->packet, NULL, NULL,
++					   reply->packet->options,
++					   reply->opt_state, &global_scope,
++					   oc, MDL) ||
++		    (data.len != 4)) {
++			log_error("Invalid renewal time.");
++		} else {
++			reply->renew = getULong(data.data);
++		}
++
++		if (data.data != NULL)
++			data_string_forget(&data, MDL);
++	}
++	putULong(reply->buf.data + ia_cursor + 8, reply->renew);
++
++	/* Now T2. */
++	reply->rebind = 0;
++	oc = lookup_option(&dhcp_universe, reply->opt_state,
++			   DHO_DHCP_REBINDING_TIME);
++	if (oc != NULL) {
++		if (!evaluate_option_cache(&data, reply->packet, NULL, NULL,
++					   reply->packet->options,
++					   reply->opt_state, &global_scope,
++					   oc, MDL) ||
++		    (data.len != 4)) {
++			log_error("Invalid rebinding time.");
++		} else {
++			reply->rebind = getULong(data.data);
++		}
++
++		if (data.data != NULL)
++			data_string_forget(&data, MDL);
++	}
++	putULong(reply->buf.data + ia_cursor + 12, reply->rebind);
++
++	/*
++	 * If this is not a 'soft' binding, consume the new changes into
++	 * the database (if any have been attached to the ia_na).
++	 *
++	 * Loop through the assigned dynamic addresses, referencing the
++	 * leases onto this IA_NA rather than any old ones, and updating
++	 * pool timers for each (if any).
++	 */
++	if ((status != ISC_R_CANCELED) && !reply->static_lease &&
++	    (reply->buf.reply.msg_type == DHCPV6_REPLY) &&
++	    (reply->ia->num_iasubopt != 0)) {
++		struct iasubopt *tmp;
++		struct data_string *ia_id;
++		int i;
++
++		for (i = 0 ; i < reply->ia->num_iasubopt ; i++) {
++			tmp = reply->ia->iasubopt[i];
++
++			if (tmp->ia != NULL)
++				ia_dereference(&tmp->ia, MDL);
++			ia_reference(&tmp->ia, reply->ia, MDL);
++
++			/* Commit 'hard' bindings. */
++			tmp->hard_lifetime_end_time =
++				tmp->soft_lifetime_end_time;
++			tmp->soft_lifetime_end_time = 0;
++			renew_lease6(tmp->ipv6_pool, tmp);
++			schedule_lease_timeout(tmp->ipv6_pool);
++
++			/*
++			 * Perform ddns updates.
++			 */
++			oc = lookup_option(&server_universe, reply->opt_state,
++					   SV_DDNS_UPDATES);
++			if ((oc == NULL) ||
++			    evaluate_boolean_option_cache(NULL, reply->packet,
++							  NULL, NULL,
++							reply->packet->options,
++							  reply->opt_state,
++							  &tmp->scope,
++							  oc, MDL)) {
++				ddns_updates(reply->packet, NULL, NULL,
++					     tmp, NULL, reply->opt_state);
++			}
++		}
++
++		/* Remove any old ia from the hash. */
++		if (reply->old_ia != NULL) {
++			ia_id = &reply->old_ia->iaid_duid;
++			ia_hash_delete(ia_na_active,
++				       (unsigned char *)ia_id->data,
++				       ia_id->len, MDL);
++			ia_dereference(&reply->old_ia, MDL);
++		}
++
++		/* Put new ia into the hash. */
++		reply->ia->cltt = cur_time;
++		ia_id = &reply->ia->iaid_duid;
++		ia_hash_add(ia_na_active, (unsigned char *)ia_id->data,
++			    ia_id->len, reply->ia, MDL);
++
++		write_ia(reply->ia);
++	}
++
++      cleanup:
++	if (packet_ia != NULL)
++		option_state_dereference(&packet_ia, MDL);
++	if (reply->reply_ia != NULL)
++		option_state_dereference(&reply->reply_ia, MDL);
++	if (ia_data.data != NULL)
++		data_string_forget(&ia_data, MDL);
++	if (data.data != NULL)
++		data_string_forget(&data, MDL);
++	if (reply->ia != NULL)
++		ia_dereference(&reply->ia, MDL);
++	if (reply->old_ia != NULL)
++		ia_dereference(&reply->old_ia, MDL);
++	if (reply->lease != NULL)
++		iasubopt_dereference(&reply->lease, MDL);
++	if (reply->fixed.data != NULL)
++		data_string_forget(&reply->fixed, MDL);
++	if (reply->subnet != NULL)
++		subnet_dereference(&reply->subnet, MDL);
++
++	/*
++	 * ISC_R_CANCELED is a status code used by the addr processing to
++	 * indicate we're replying with a status code.  This is still a
++	 * success at higher layers.
++	 */
++	return((status == ISC_R_CANCELED) ? ISC_R_SUCCESS : status);
++}
++
++/*
++ * Process an IAADDR within a given IA_xA, storing any IAADDR reply contents
++ * into the reply's current ia-scoped option cache.  Returns ISC_R_CANCELED
++ * in the event we are replying with a status code and do not wish to process
++ * more IAADDRs within this IA.
++ */
++static isc_result_t
++reply_process_addr(struct reply_state *reply, struct option_cache *addr) {
++	u_int32_t pref_life, valid_life;
++	struct binding_scope **scope;
++	struct group *group;
++	struct subnet *subnet;
++	struct iaddr tmp_addr;
++	struct option_cache *oc;
++	struct data_string iaaddr, data;
++	isc_result_t status = ISC_R_SUCCESS;
++
++	/* Initializes values that will be cleaned up. */
++	memset(&iaaddr, 0, sizeof(iaaddr));
++	memset(&data, 0, sizeof(data));
++	/* Note that reply->lease may be set by address_is_owned() */
++
++	/*
++	 * There is no point trying to process an incoming address if there
++	 * is no room for an outgoing address.
++	 */
++	if ((reply->cursor + 28) > sizeof(reply->buf)) {
++		log_error("reply_process_addr: Out of room for address.");
++		return ISC_R_NOSPACE;
++	}
++
++	/* Extract this IAADDR option. */
++	if (!evaluate_option_cache(&iaaddr, reply->packet, NULL, NULL, 
++				   reply->packet->options, NULL, &global_scope,
++				   addr, MDL) ||
++	    (iaaddr.len < IAADDR_OFFSET)) {
++		log_error("reply_process_addr: error evaluating IAADDR.");
++		status = ISC_R_FAILURE;
++		goto cleanup;
++	}
++
++	/* The first 16 bytes are the IPv6 address. */
++	pref_life = getULong(iaaddr.data + 16);
++	valid_life = getULong(iaaddr.data + 20);
++
++	if ((reply->client_valid == 0) ||
++	    (reply->client_valid > valid_life))
++		reply->client_valid = valid_life;
++
++	if ((reply->client_prefer == 0) ||
++	    (reply->client_prefer > pref_life))
++		reply->client_prefer = pref_life;
++
++	/* 
++	 * Clients may choose to send :: as an address, with the idea to give
++	 * hints about preferred-lifetime or valid-lifetime.
++	 */
++	tmp_addr.len = 16;
++	memset(tmp_addr.iabuf, 0, 16);
++	if (!memcmp(iaaddr.data, tmp_addr.iabuf, 16)) {
++		/* Status remains success; we just ignore this one. */
++		goto cleanup;
++	}
++
++	/* tmp_addr len remains 16 */
++	memcpy(tmp_addr.iabuf, iaaddr.data, 16);
++
++	/*
++	 * Verify that this address is on the client's network.
++	 */
++	for (subnet = reply->shared->subnets ; subnet != NULL ;
++	     subnet = subnet->next_sibling) {
++		if (addr_eq(subnet_number(tmp_addr, subnet->netmask),
++			    subnet->net))
++			break;
++	}
++
++	/* Address not found on shared network. */
++	if (subnet == NULL) {
++		/* Ignore this address on 'soft' bindings. */
++		if (reply->packet->dhcpv6_msg_type == DHCPV6_SOLICIT) {
++			/* disable rapid commit */
++			reply->buf.reply.msg_type = DHCPV6_ADVERTISE;
++			delete_option(&dhcpv6_universe,
++				      reply->opt_state,
++				      D6O_RAPID_COMMIT);
++			/* status remains success */
++			goto cleanup;
++		}
++
++		/*
++		 * RFC3315 section 18.2.1:
++		 *
++		 * If the server finds that the prefix on one or more IP
++		 * addresses in any IA in the message from the client is not
++		 * appropriate for the link to which the client is connected,
++		 * the server MUST return the IA to the client with a Status
++		 * Code option with the value NotOnLink.
++		 */
++		if (reply->packet->dhcpv6_msg_type == DHCPV6_REQUEST) {
++			/* Rewind the IA_NA to empty. */
++			option_state_dereference(&reply->reply_ia, MDL);
++			if (!option_state_allocate(&reply->reply_ia, MDL)) {
++				log_error("reply_process_addr: No memory for "
++					  "option state wipe.");
++				status = ISC_R_NOMEMORY;
++				goto cleanup;
++			}
++
++			/* Append a NotOnLink status code. */
++			if (!set_status_code(STATUS_NotOnLink,
++					     "Address not for use on this "
++					     "link.", reply->reply_ia)) {
++				log_error("reply_process_addr: Failure "
++					  "setting status code.");
++				status = ISC_R_FAILURE;
++				goto cleanup;
++			}
++
++			/* Fin (no more IAADDRs). */
++			status = ISC_R_CANCELED;
++			goto cleanup;
++		}
++
++		/*
++		 * RFC3315 sections 18.2.3 and 18.2.4 have identical language:
++		 *
++		 * If the server finds that any of the addresses are not
++		 * appropriate for the link to which the client is attached,
++		 * the server returns the address to the client with lifetimes
++		 * of 0.
++		 */
++		if ((reply->packet->dhcpv6_msg_type != DHCPV6_RENEW) &&
++		    (reply->packet->dhcpv6_msg_type != DHCPV6_REBIND)) {
++			log_error("It is impossible to lease a client that is "
++				  "not sending a solicit, request, renew, or "
++				  "rebind.");
++			status = ISC_R_FAILURE;
++			goto cleanup;
++		}
++
++		reply->send_prefer = reply->send_valid = 0;
++		goto send_addr;
++	}
++
++	/* Verify the address belongs to the client. */
++	if (!address_is_owned(reply, &tmp_addr)) {
++		/*
++		 * For solicit and request, any addresses included are
++		 * 'requested' addresses.  For rebind, we actually have
++		 * no direction on what to do from 3315 section 18.2.4!
++		 * So I think the best bet is to try and give it out, and if
++		 * we can't, zero lifetimes.
++		 */
++		if ((reply->packet->dhcpv6_msg_type == DHCPV6_SOLICIT) ||
++		    (reply->packet->dhcpv6_msg_type == DHCPV6_REQUEST) ||
++		    (reply->packet->dhcpv6_msg_type == DHCPV6_REBIND)) {
++			status = reply_process_try_addr(reply, &tmp_addr);
++
++			/*
++			 * If the address is in use, or isn't in any dynamic
++			 * range, continue as normal.  If any other error was
++			 * found, error out.
++			 */
++			if ((status != ISC_R_SUCCESS) && 
++			    (status != ISC_R_ADDRINUSE) &&
++			    (status != ISC_R_ADDRNOTAVAIL))
++				goto cleanup;
++
++			/*
++			 * If we didn't honor this lease, for solicit and
++			 * request we simply omit it from our answer.  For
++			 * rebind, we send it with zeroed lifetimes.
++			 */
++			if (reply->lease == NULL) {
++				if (reply->packet->dhcpv6_msg_type ==
++							DHCPV6_REBIND) {
++					reply->send_prefer = 0;
++					reply->send_valid = 0;
++					goto send_addr;
++				}
++
++				/* status remains success - ignore */
++				goto cleanup;
++			}
++		/*
++		 * RFC3315 section 18.2.3:
++		 *
++		 * If the server cannot find a client entry for the IA the
++		 * server returns the IA containing no addresses with a Status
++		 * Code option set to NoBinding in the Reply message.
++		 *
++		 * On mismatch we (ab)use this pretending we have not the IA
++		 * as soon as we have not an address.
++		 */
++		} else if (reply->packet->dhcpv6_msg_type == DHCPV6_RENEW) {
++			/* Rewind the IA_NA to empty. */
++			option_state_dereference(&reply->reply_ia, MDL);
++			if (!option_state_allocate(&reply->reply_ia, MDL)) {
++				log_error("reply_process_addr: No memory for "
++					  "option state wipe.");
++				status = ISC_R_NOMEMORY;
++				goto cleanup;
++			}
++
++			/* Append a NoBinding status code.  */
++			if (!set_status_code(STATUS_NoBinding,
++					     "Address not bound to this "
++					     "interface.", reply->reply_ia)) {
++				log_error("reply_process_addr: Unable to "
++					  "attach status code.");
++				status = ISC_R_FAILURE;
++				goto cleanup;
++			}
++
++			/* Fin (no more IAADDRs). */
++			status = ISC_R_CANCELED;
++			goto cleanup;
++		} else {
++			log_error("It is impossible to lease a client that is "
++				  "not sending a solicit, request, renew, or "
++				  "rebind message.");
++			status = ISC_R_FAILURE;
++			goto cleanup;
++		}
++	}
++
++	if (reply->static_lease) {
++		if (reply->host == NULL)
++			log_fatal("Impossible condition at %s:%d.", MDL);
++
++		scope = &global_scope;
++		group = reply->subnet->group;
++	} else {
++		if (reply->lease == NULL)
++			log_fatal("Impossible condition at %s:%d.", MDL);
++
++		scope = &reply->lease->scope;
++		group = reply->lease->ipv6_pool->subnet->group;
++	}
++
++	/*
++	 * If client_resources is nonzero, then the reply_process_is_addressed
++	 * function has executed configuration state into the reply option
++	 * cache.  We will use that valid cache to derive configuration for
++	 * whether or not to engage in additional addresses, and similar.
++	 */
++	if (reply->client_resources != 0) {
++		unsigned limit = 1;
++
++		/*
++		 * Does this client have "enough" addresses already?  Default
++		 * to one.  Everybody gets one, and one should be enough for
++		 * anybody.
++		 */
++		oc = lookup_option(&server_universe, reply->opt_state,
++				   SV_LIMIT_ADDRS_PER_IA);
++		if (oc != NULL) {
++			if (!evaluate_option_cache(&data, reply->packet,
++						   NULL, NULL,
++						   reply->packet->options,
++						   reply->opt_state,
++						   scope, oc, MDL) ||
++			    (data.len != 4)) {
++				log_error("reply_process_addr: unable to "
++					  "evaluate addrs-per-ia value.");
++				status = ISC_R_FAILURE;
++				goto cleanup;
++			}
++
++			limit = getULong(data.data);
++			data_string_forget(&data, MDL);
++		}
++
++		/*
++		 * If we wish to limit the client to a certain number of
++		 * addresses, then omit the address from the reply.
++		 */
++		if (reply->client_resources >= limit)
++			goto cleanup;
++	}
++
++	status = reply_process_is_addressed(reply, scope, group);
++	if (status != ISC_R_SUCCESS)
++		goto cleanup;
++
++      send_addr:
++	status = reply_process_send_addr(reply, &tmp_addr);
++
++      cleanup:
++	if (iaaddr.data != NULL)
++		data_string_forget(&iaaddr, MDL);
++	if (data.data != NULL)
++		data_string_forget(&data, MDL);
++	if (reply->lease != NULL)
++		iasubopt_dereference(&reply->lease, MDL);
++
++	return status;
++}
++
++/*
++ * Verify the address belongs to the client.  If we've got a host
++ * record with a fixed address, it has to be the assigned address
++ * (fault out all else).  Otherwise it's a dynamic address, so lookup
++ * that address and make sure it belongs to this DUID:IAID pair.
++ */
++static isc_boolean_t
++address_is_owned(struct reply_state *reply, struct iaddr *addr) {
++	int i;
++
++	/*
++	 * This faults out addresses that don't match fixed addresses.
++	 */
++	if (reply->static_lease) {
++		if (reply->fixed.data == NULL)
++			log_fatal("Impossible condition at %s:%d.", MDL);
++
++		if (memcmp(addr->iabuf, reply->fixed.data, 16) == 0)
++			return ISC_TRUE;
++
++		return ISC_FALSE;
++	}
++
++	if ((reply->old_ia == NULL) || (reply->old_ia->num_iasubopt == 0))
++		return ISC_FALSE;
++
++	for (i = 0 ; i < reply->old_ia->num_iasubopt ; i++) {
++		struct iasubopt *tmp;
++
++		tmp = reply->old_ia->iasubopt[i];
++
++		if (memcmp(addr->iabuf, &tmp->addr, 16) == 0) {
++			iasubopt_reference(&reply->lease, tmp, MDL);
++			return ISC_TRUE;
++		}
++	}
++
++	return ISC_FALSE;
++}
++
++/* Process a client-supplied IA_TA.  This may append options to the tail of
++ * the reply packet being built in the reply_state structure.
++ */
++static isc_result_t
++reply_process_ia_ta(struct reply_state *reply, struct option_cache *ia) {
++	isc_result_t status = ISC_R_SUCCESS;
++	u_int32_t iaid;
++	unsigned ia_cursor;
++	struct option_state *packet_ia;
++	struct option_cache *oc;
++	struct data_string ia_data, data;
++	struct data_string iaaddr;
++	u_int32_t pref_life, valid_life;
++	struct iaddr tmp_addr;
++
++	/* Initialize values that will get cleaned up on return. */
++	packet_ia = NULL;
++	memset(&ia_data, 0, sizeof(ia_data));
++	memset(&data, 0, sizeof(data));
++	memset(&iaaddr, 0, sizeof(iaaddr));
++
++	/* Make sure there is at least room for the header. */
++	if ((reply->cursor + IA_TA_OFFSET + 4) > sizeof(reply->buf)) {
++		log_error("reply_process_ia_ta: Reply too long for IA.");
++		return ISC_R_NOSPACE;
++	}
++
++
++	/* Fetch the IA_TA contents. */
++	if (!get_encapsulated_IA_state(&packet_ia, &ia_data, reply->packet,
++				       ia, IA_TA_OFFSET)) {
++		log_error("reply_process_ia_ta: error evaluating ia");
++		status = ISC_R_FAILURE;
++		goto cleanup;
++	}
++
++	/* Extract IA_TA header contents. */
++	iaid = getULong(ia_data.data);
++
++	/* Create an IA_TA structure. */
++	if (ia_allocate(&reply->ia, iaid, (char *)reply->client_id.data,
++			reply->client_id.len, MDL) != ISC_R_SUCCESS) {
++		log_error("reply_process_ia_ta: no memory for ia.");
++		status = ISC_R_NOMEMORY;
++		goto cleanup;
++	}
++	reply->ia->ia_type = D6O_IA_TA;
++
++	/* Cache pre-existing IA, if any. */
++	ia_hash_lookup(&reply->old_ia, ia_ta_active,
++		       (unsigned char *)reply->ia->iaid_duid.data,
++		       reply->ia->iaid_duid.len, MDL);
++
++	/*
++	 * Create an option cache to carry the IA_TA option contents, and
++	 * execute any user-supplied values into it.
++	 */
++	if (!option_state_allocate(&reply->reply_ia, MDL)) {
++		status = ISC_R_NOMEMORY;
++		goto cleanup;
++	}
++
++	/*
++	 * Temporary leases are dynamic by definition.
++	 */
++	reply->static_lease = ISC_FALSE;
++
++	/*
++	 * Save the cursor position at the start of the IA, so we can
++	 * set length later.  We write a temporary
++	 * header out now just in case we decide to adjust the packet
++	 * within sub-process functions.
++	 */
++	ia_cursor = reply->cursor;
++
++	/* Initialize the IA_TA header.  First the code. */
++	putUShort(reply->buf.data + reply->cursor, (unsigned)D6O_IA_TA);
++	reply->cursor += 2;
++
++	/* Then option length. */
++	putUShort(reply->buf.data + reply->cursor, 0x04u);
++	reply->cursor += 2;
++
++	/* Then IA_TA header contents; IAID. */
++	putULong(reply->buf.data + reply->cursor, iaid);
++	reply->cursor += 4;
++
++	/* 
++	 * Deal with an IAADDR for lifetimes.
++	 * For all or none, process IAADDRs as hints.
++	 */
++	reply->valid = reply->prefer = 0xffffffff;
++	reply->client_valid = reply->client_prefer = 0;
++	oc = lookup_option(&dhcpv6_universe, packet_ia, D6O_IAADDR);
++	for (; oc != NULL; oc = oc->next) {
++		memset(&iaaddr, 0, sizeof(iaaddr));
++		if (!evaluate_option_cache(&iaaddr, reply->packet,
++					   NULL, NULL,
++					   reply->packet->options, NULL,
++					   &global_scope, oc, MDL) ||
++		    (iaaddr.len < IAADDR_OFFSET)) {
++			log_error("reply_process_ia_ta: error "
++				  "evaluating IAADDR.");
++			status = ISC_R_FAILURE;
++			goto cleanup;
++		}
++		/* The first 16 bytes are the IPv6 address. */
++		pref_life = getULong(iaaddr.data + 16);
++		valid_life = getULong(iaaddr.data + 20);
++
++		if ((reply->client_valid == 0) ||
++		    (reply->client_valid > valid_life))
++			reply->client_valid = valid_life;
++
++		if ((reply->client_prefer == 0) ||
++		    (reply->client_prefer > pref_life))
++			reply->client_prefer = pref_life;
++
++		/* Nothing more if something has failed. */
++		if (status == ISC_R_CANCELED)
++			continue;
++
++		tmp_addr.len = 16;
++		memcpy(tmp_addr.iabuf, iaaddr.data, 16);
++		if (!temporary_is_available(reply, &tmp_addr))
++			goto bad_temp;
++		status = reply_process_is_addressed(reply,
++						    &reply->lease->scope,
++						    reply->shared->group);
++		if (status != ISC_R_SUCCESS)
++			goto bad_temp;
++		status = reply_process_send_addr(reply, &tmp_addr);
++		if (status != ISC_R_SUCCESS)
++			goto bad_temp;
++		if (reply->lease != NULL)
++			iasubopt_dereference(&reply->lease, MDL);
++		continue;
++
++	bad_temp:
++		/* Rewind the IA_TA to empty. */
++		option_state_dereference(&reply->reply_ia, MDL);
++		if (!option_state_allocate(&reply->reply_ia, MDL)) {
++			status = ISC_R_NOMEMORY;
++			goto cleanup;
++		}
++		status = ISC_R_CANCELED;
++		reply->client_resources = 0;
++		reply->resources_included = ISC_FALSE;
++		if (reply->lease != NULL)
++			iasubopt_dereference(&reply->lease, MDL);
++	}
++	reply->ia_count++;
++
++	/*
++	 * Give the client temporary addresses.
++	 */
++	if (reply->client_resources != 0)
++		goto store;
++	status = find_client_temporaries(reply);
++	if (status == ISC_R_NORESOURCES) {
++		switch (reply->packet->dhcpv6_msg_type) {
++		      case DHCPV6_SOLICIT:
++			/*
++			 * No address for any IA is handled
++			 * by the caller.
++			 */
++			/* FALL THROUGH */
++
++		      case DHCPV6_REQUEST:
++			/* Section 18.2.1 (Request):
++			 *
++			 * If the server cannot assign any addresses to
++			 * an IA in the message from the client, the
++			 * server MUST include the IA in the Reply
++			 * message with no addresses in the IA and a
++			 * Status Code option in the IA containing
++			 * status code NoAddrsAvail.
++			 */
++			option_state_dereference(&reply->reply_ia, MDL);
++			if (!option_state_allocate(&reply->reply_ia,  MDL)) {
++				log_error("reply_process_ia_ta: No "
++					  "memory for option state wipe.");
++				status = ISC_R_NOMEMORY;
++				goto cleanup;
++			}
++
++			if (!set_status_code(STATUS_NoAddrsAvail,
++					     "No addresses available "
++					     "for this interface.",
++					      reply->reply_ia)) {
++				log_error("reply_process_ia_ta: Unable "
++					  "to set NoAddrsAvail status code.");
++				status = ISC_R_FAILURE;
++				goto cleanup;
++			}
++
++			status = ISC_R_SUCCESS;
++			break;
++
++		      default:
++			/*
++			 * We don't want to include the IA if we
++			 * provide zero addresses including zeroed
++			 * lifetimes.
++			 */
++			if (reply->resources_included)
++				status = ISC_R_SUCCESS;
++			else
++				goto cleanup;
++			break;
++		}
++	} else if (status != ISC_R_SUCCESS)
++		goto cleanup;
++
++      store:
++	reply->cursor += store_options6((char *)reply->buf.data + reply->cursor,
++					sizeof(reply->buf) - reply->cursor,
++					reply->reply_ia, reply->packet,
++					required_opts_IA, NULL);
++
++	/* Reset the length of this IA to match what was just written. */
++	putUShort(reply->buf.data + ia_cursor + 2,
++		  reply->cursor - (ia_cursor + 4));
++
++	/*
++	 * Consume the new changes into the database (if any have been
++	 * attached to the ia_ta).
++	 *
++	 * Loop through the assigned dynamic addresses, referencing the
++	 * leases onto this IA_TA rather than any old ones, and updating
++	 * pool timers for each (if any).
++	 */
++	if ((status != ISC_R_CANCELED) &&
++	    (reply->buf.reply.msg_type == DHCPV6_REPLY) &&
++	    (reply->ia->num_iasubopt != 0)) {
++		struct iasubopt *tmp;
++		struct data_string *ia_id;
++		int i;
++
++		for (i = 0 ; i < reply->ia->num_iasubopt ; i++) {
++			tmp = reply->ia->iasubopt[i];
++
++			if (tmp->ia != NULL)
++				ia_dereference(&tmp->ia, MDL);
++			ia_reference(&tmp->ia, reply->ia, MDL);
++
++			/* Commit 'hard' bindings. */
++			tmp->hard_lifetime_end_time =
++				tmp->soft_lifetime_end_time;
++			tmp->soft_lifetime_end_time = 0;
++			renew_lease6(tmp->ipv6_pool, tmp);
++			schedule_lease_timeout(tmp->ipv6_pool);
++
++			/*
++			 * Perform ddns updates.
++			 */
++			oc = lookup_option(&server_universe, reply->opt_state,
++					   SV_DDNS_UPDATES);
++			if ((oc == NULL) ||
++			    evaluate_boolean_option_cache(NULL, reply->packet,
++							  NULL, NULL,
++							reply->packet->options,
++							  reply->opt_state,
++							  &tmp->scope,
++							  oc, MDL)) {
++				ddns_updates(reply->packet, NULL, NULL,
++					     tmp, NULL, reply->opt_state);
++			}
++		}
++
++		/* Remove any old ia from the hash. */
++		if (reply->old_ia != NULL) {
++			ia_id = &reply->old_ia->iaid_duid;
++			ia_hash_delete(ia_ta_active,
++				       (unsigned char *)ia_id->data,
++				       ia_id->len, MDL);
++			ia_dereference(&reply->old_ia, MDL);
++		}
++
++		/* Put new ia into the hash. */
++		reply->ia->cltt = cur_time;
++		ia_id = &reply->ia->iaid_duid;
++		ia_hash_add(ia_ta_active, (unsigned char *)ia_id->data,
++			    ia_id->len, reply->ia, MDL);
++
++		write_ia(reply->ia);
++	}
++
++      cleanup:
++	if (packet_ia != NULL)
++		option_state_dereference(&packet_ia, MDL);
++	if (iaaddr.data != NULL)
++		data_string_forget(&iaaddr, MDL);
++	if (reply->reply_ia != NULL)
++		option_state_dereference(&reply->reply_ia, MDL);
++	if (ia_data.data != NULL)
++		data_string_forget(&ia_data, MDL);
++	if (data.data != NULL)
++		data_string_forget(&data, MDL);
++	if (reply->ia != NULL)
++		ia_dereference(&reply->ia, MDL);
++	if (reply->old_ia != NULL)
++		ia_dereference(&reply->old_ia, MDL);
++	if (reply->lease != NULL)
++		iasubopt_dereference(&reply->lease, MDL);
++
++	/*
++	 * ISC_R_CANCELED is a status code used by the addr processing to
++	 * indicate we're replying with other addresses.  This is still a
++	 * success at higher layers.
++	 */
++	return((status == ISC_R_CANCELED) ? ISC_R_SUCCESS : status);
++}
++
++/*
++ * Verify the temporary address is available.
++ */
++static isc_boolean_t
++temporary_is_available(struct reply_state *reply, struct iaddr *addr) {
++	struct in6_addr tmp_addr;
++	struct subnet *subnet;
++	struct ipv6_pool *pool;
++	int i;
++
++	memcpy(&tmp_addr, addr->iabuf, sizeof(tmp_addr));
++	/*
++	 * Clients may choose to send :: as an address, with the idea to give
++	 * hints about preferred-lifetime or valid-lifetime.
++	 * So this is not a request for this address.
++	 */
++	if (IN6_IS_ADDR_UNSPECIFIED(&tmp_addr))
++		return ISC_FALSE;
++
++	/*
++	 * Verify that this address is on the client's network.
++	 */
++	for (subnet = reply->shared->subnets ; subnet != NULL ;
++	     subnet = subnet->next_sibling) {
++		if (addr_eq(subnet_number(*addr, subnet->netmask),
++			    subnet->net))
++			break;
++	}
++
++	/* Address not found on shared network. */
++	if (subnet == NULL)
++		return ISC_FALSE;
++
++	/*
++	 * Check if this address is owned (must be before next step).
++	 */
++	if (address_is_owned(reply, addr))
++		return ISC_TRUE;
++
++	/*
++	 * Verify that this address is in a temporary pool and try to get it.
++	 */
++	if (reply->shared->ipv6_pools == NULL)
++		return ISC_FALSE;
++	for (i = 0 ; (pool = reply->shared->ipv6_pools[i]) != NULL ; i++) {
++		if (pool->pool_type != D6O_IA_TA)
++			continue;
++		if (ipv6_in_pool(&tmp_addr, pool))
++			break;
++	}
++	if (pool == NULL)
++		return ISC_FALSE;
++	if (lease6_exists(pool, &tmp_addr))
++		return ISC_FALSE;
++	if (iasubopt_allocate(&reply->lease, MDL) != ISC_R_SUCCESS)
++		return ISC_FALSE;
++	reply->lease->addr = tmp_addr;
++	reply->lease->plen = 0;
++	/* Default is soft binding for 2 minutes. */
++	if (add_lease6(pool, reply->lease, cur_time + 120) != ISC_R_SUCCESS)
++		return ISC_FALSE;
++
++	return ISC_TRUE;
++}
++
++/*
++ * Get a temporary address per prefix.
++ */
++static isc_result_t
++find_client_temporaries(struct reply_state *reply) {
++	struct shared_network *shared;
++	int i;
++	struct ipv6_pool *p;
++	isc_result_t status;
++	unsigned int attempts;
++	struct iaddr send_addr;
++
++	/*
++	 * No pools, we're done.
++	 */
++	shared = reply->shared;
++	if (shared->ipv6_pools == NULL) {
++		log_debug("Unable to get client addresses: "
++			  "no IPv6 pools on this shared network");
++		return ISC_R_NORESOURCES;
++	}
++
++	status = ISC_R_NORESOURCES;
++	for (i = 0;; i++) {
++		p = shared->ipv6_pools[i];
++		if (p == NULL) {
++			break;
++		}
++		if (p->pool_type != D6O_IA_TA) {
++			continue;
++		}
++
++		/*
++		 * Get an address in this temporary pool.
++		 */
++		status = create_lease6(p, &reply->lease, &attempts,
++				       &reply->client_id, cur_time + 120);
++		if (status != ISC_R_SUCCESS) {
++			log_debug("Unable to get a temporary address.");
++			goto cleanup;
++		}
++
++		status = reply_process_is_addressed(reply,
++						    &reply->lease->scope,
++				      reply->lease->ipv6_pool->subnet->group);
++		if (status != ISC_R_SUCCESS) {
++			goto cleanup;
++		}
++		send_addr.len = 16;
++		memcpy(send_addr.iabuf, &reply->lease->addr, 16);
++		status = reply_process_send_addr(reply, &send_addr);
++		if (status != ISC_R_SUCCESS) {
++			goto cleanup;
++		}
++		if (reply->lease != NULL) {
++			iasubopt_dereference(&reply->lease, MDL);
++		}
++	}
++
++      cleanup:
++	if (reply->lease != NULL) {
++		iasubopt_dereference(&reply->lease, MDL);
++	}
++	return status;
++}
++
++/*
++ * This function only returns failure on 'hard' failures.  If it succeeds,
++ * it will leave a lease structure behind.
++ */
++static isc_result_t
++reply_process_try_addr(struct reply_state *reply, struct iaddr *addr) {
++	isc_result_t status = ISC_R_NORESOURCES;
++	struct ipv6_pool *pool;
++	int i;
++	struct data_string data_addr;
++
++	if ((reply == NULL) || (reply->shared == NULL) ||
++	    (reply->shared->ipv6_pools == NULL) || (addr == NULL) ||
++	    (reply->lease != NULL))
++		return ISC_R_INVALIDARG;
++
++	memset(&data_addr, 0, sizeof(data_addr));
++	data_addr.len = addr->len;
++	data_addr.data = addr->iabuf;
++
++	for (i = 0 ; (pool = reply->shared->ipv6_pools[i]) != NULL ; i++) {
++		if (pool->pool_type != D6O_IA_NA)
++			continue;
++		status = try_client_v6_address(&reply->lease, pool,
++					       &data_addr);
++		if (status == ISC_R_SUCCESS)
++			break;
++	}
++
++	/* Note that this is just pedantry.  There is no allocation to free. */
++	data_string_forget(&data_addr, MDL);
++	/* Return just the most recent status... */
++	return status;
++}
++
++/* Look around for an address to give the client.  First, look through the
++ * old IA for addresses we can extend.  Second, try to allocate a new address.
++ * Finally, actually add that address into the current reply IA.
++ */
++static isc_result_t
++find_client_address(struct reply_state *reply) {
++	struct iaddr send_addr;
++	isc_result_t status = ISC_R_NORESOURCES;
++	struct iasubopt *lease, *best_lease = NULL;
++	struct binding_scope **scope;
++	struct group *group;
++	int i;
++
++	if (reply->static_lease) {
++		if (reply->host == NULL)
++			return ISC_R_INVALIDARG;
++
++		send_addr.len = 16;
++		memcpy(send_addr.iabuf, reply->fixed.data, 16);
++
++		status = ISC_R_SUCCESS;
++		scope = &global_scope;
++		group = reply->subnet->group;
++		goto send_addr;
++	}
++
++	if (reply->old_ia != NULL)  {
++		for (i = 0 ; i < reply->old_ia->num_iasubopt ; i++) {
++			struct shared_network *candidate_shared;
++
++			lease = reply->old_ia->iasubopt[i];
++			candidate_shared = lease->ipv6_pool->shared_network;
++
++			/*
++			 * Look for the best lease on the client's shared
++			 * network.
++			 */
++			if (candidate_shared == reply->shared) {
++				best_lease = lease_compare(lease, best_lease);
++			}
++		}
++	}
++
++	/* Try to pick a new address if we didn't find one, or if we found an
++	 * abandoned lease.
++	 */
++	if ((best_lease == NULL) || (best_lease->state == FTS_ABANDONED)) {
++		status = pick_v6_address(&reply->lease, reply->shared,
++					 &reply->client_id);
++	} else if (best_lease != NULL) {
++		iasubopt_reference(&reply->lease, best_lease, MDL);
++		status = ISC_R_SUCCESS;
++	}
++
++	/* Pick the abandoned lease as a last resort. */
++	if ((status == ISC_R_NORESOURCES) && (best_lease != NULL)) {
++		/* I don't see how this is supposed to be done right now. */
++		log_error("Reclaiming abandoned addresses is not yet "
++			  "supported.  Treating this as an out of space "
++			  "condition.");
++		/* iasubopt_reference(&reply->lease, best_lease, MDL); */
++	}
++
++	/* Give up now if we didn't find a lease. */
++	if (status != ISC_R_SUCCESS)
++		return status;
++
++	if (reply->lease == NULL)
++		log_fatal("Impossible condition at %s:%d.", MDL);
++
++	/* Draw binding scopes from the lease's binding scope, and config
++	 * from the lease's containing subnet and higher.  Note that it may
++	 * be desirable to place the group attachment directly in the pool.
++	 */
++	scope = &reply->lease->scope;
++	group = reply->lease->ipv6_pool->subnet->group;
++
++	send_addr.len = 16;
++	memcpy(send_addr.iabuf, &reply->lease->addr, 16);
++
++      send_addr:
++	status = reply_process_is_addressed(reply, scope, group);
++	if (status != ISC_R_SUCCESS)
++		return status;
++
++	status = reply_process_send_addr(reply, &send_addr);
++	return status;
++}
++
++/* Once an address is found for a client, perform several common functions;
++ * Calculate and store valid and preferred lease times, draw client options
++ * into the option state.
++ */
++static isc_result_t
++reply_process_is_addressed(struct reply_state *reply,
++			   struct binding_scope **scope, struct group *group)
++{
++	isc_result_t status = ISC_R_SUCCESS;
++	struct data_string data;
++	struct option_cache *oc;
++
++	/* Initialize values we will cleanup. */
++	memset(&data, 0, sizeof(data));
++
++	/*
++	 * Bring configured options into the root packet level cache - start
++	 * with the lease's closest enclosing group (passed in by the caller
++	 * as 'group').
++	 */
++	execute_statements_in_scope(NULL, reply->packet, NULL, NULL,
++				    reply->packet->options, reply->opt_state,
++				    scope, group, root_group);
++
++	/*
++	 * If there is a host record, over-ride with values configured there,
++	 * without re-evaluating configuration from the previously executed
++	 * group or its common enclosers.
++	 */
++	if (reply->host != NULL)
++		execute_statements_in_scope(NULL, reply->packet, NULL, NULL,
++					    reply->packet->options,
++					    reply->opt_state, scope,
++					    reply->host->group, group);
++
++	/* Determine valid lifetime. */
++	if (reply->client_valid == 0)
++		reply->send_valid = DEFAULT_DEFAULT_LEASE_TIME;
++	else
++		reply->send_valid = reply->client_valid;
++
++	oc = lookup_option(&server_universe, reply->opt_state,
++			   SV_DEFAULT_LEASE_TIME);
++	if (oc != NULL) {
++		if (!evaluate_option_cache(&data, reply->packet, NULL, NULL,
++					   reply->packet->options,
++					   reply->opt_state,
++					   scope, oc, MDL) ||
++		    (data.len != 4)) {
++			log_error("reply_process_is_addressed: unable to "
++				  "evaluate default lease time");
++			status = ISC_R_FAILURE;
++			goto cleanup;
++		}
++
++		reply->send_valid = getULong(data.data);
++		data_string_forget(&data, MDL);
++	}
++
++	if (reply->client_prefer == 0)
++		reply->send_prefer = reply->send_valid;
++	else
++		reply->send_prefer = reply->client_prefer;
++
++	if (reply->send_prefer >= reply->send_valid)
++		reply->send_prefer = (reply->send_valid / 2) +
++				     (reply->send_valid / 8);
++
++	oc = lookup_option(&server_universe, reply->opt_state,
++			   SV_PREFER_LIFETIME);
++	if (oc != NULL) {
++		if (!evaluate_option_cache(&data, reply->packet, NULL, NULL,
++					   reply->packet->options,
++					   reply->opt_state,
++					   scope, oc, MDL) ||
++		    (data.len != 4)) {
++			log_error("reply_process_is_addressed: unable to "
++				  "evaluate preferred lease time");
++			status = ISC_R_FAILURE;
++			goto cleanup;
++		}
++
++		reply->send_prefer = getULong(data.data);
++		data_string_forget(&data, MDL);
++	}
++
++	/* Note lowest values for later calculation of renew/rebind times. */
++	if (reply->prefer > reply->send_prefer)
++		reply->prefer = reply->send_prefer;
++
++	if (reply->valid > reply->send_valid)
++		reply->valid = reply->send_valid;
++
++#if 0
++	/*
++	 * XXX: Old 4.0.0 alpha code would change the host {} record
++	 * XXX: uid upon lease assignment.  This was intended to cover the
++	 * XXX: case where a client first identifies itself using vendor
++	 * XXX: options in a solicit, or request, but later neglects to include
++	 * XXX: these options in a Renew or Rebind.  It is not clear that this
++	 * XXX: is required, and has some startling ramifications (such as
++	 * XXX: how to recover this dynamic host {} state across restarts).
++	 */
++	if (reply->host != NULL)
++		change_host_uid(host, reply->client_id->data,
++				reply->client_id->len);
++#endif /* 0 */
++
++	/* Perform dynamic lease related update work. */
++	if (reply->lease != NULL) {
++		/* Cached lifetimes */
++		reply->lease->prefer = reply->send_prefer;
++		reply->lease->valid = reply->send_valid;
++
++		/* Advance (or rewind) the valid lifetime. */
++		if (reply->buf.reply.msg_type == DHCPV6_REPLY) {
++			reply->lease->soft_lifetime_end_time =
++				cur_time + reply->send_valid;
++			/* Wait before renew! */
++		}
++
++		status = ia_add_iasubopt(reply->ia, reply->lease, MDL);
++		if (status != ISC_R_SUCCESS) {
++			log_fatal("reply_process_is_addressed: Unable to "
++				  "attach lease to new IA: %s",
++				  isc_result_totext(status));
++		}
++
++		/*
++		 * If this is a new lease, make sure it is attached somewhere.
++		 */
++		if (reply->lease->ia == NULL) {
++			ia_reference(&reply->lease->ia, reply->ia, MDL);
++		}
++	}
++
++	/* Bring a copy of the relevant options into the IA scope. */
++	execute_statements_in_scope(NULL, reply->packet, NULL, NULL,
++				    reply->packet->options, reply->reply_ia,
++				    scope, group, root_group);
++
++	/*
++	 * And bring in host record configuration, if any, but not to overlap
++	 * the previous group or its common enclosers.
++	 */
++	if (reply->host != NULL)
++		execute_statements_in_scope(NULL, reply->packet, NULL, NULL,
++					    reply->packet->options,
++					    reply->reply_ia, scope,
++					    reply->host->group, group);
++
++      cleanup:
++	if (data.data != NULL)
++		data_string_forget(&data, MDL);
++
++	if (status == ISC_R_SUCCESS)
++		reply->client_resources++;
++
++	return status;
++}
++
++/* Simply send an IAADDR within the IA scope as described. */
++static isc_result_t
++reply_process_send_addr(struct reply_state *reply, struct iaddr *addr) {
++	isc_result_t status = ISC_R_SUCCESS;
++	struct data_string data;
++
++	memset(&data, 0, sizeof(data));
++
++	/* Now append the lease. */
++	data.len = IAADDR_OFFSET;
++	if (!buffer_allocate(&data.buffer, data.len, MDL)) {
++		log_error("reply_process_send_addr: out of memory"
++			  "allocating new IAADDR buffer.");
++		status = ISC_R_NOMEMORY;
++		goto cleanup;
++	}
++	data.data = data.buffer->data;
++
++	memcpy(data.buffer->data, addr->iabuf, 16);
++	putULong(data.buffer->data + 16, reply->send_prefer);
++	putULong(data.buffer->data + 20, reply->send_valid);
++
++	if (!append_option_buffer(&dhcpv6_universe, reply->reply_ia,
++				  data.buffer, data.buffer->data,
++				  data.len, D6O_IAADDR, 0)) {
++		log_error("reply_process_send_addr: unable "
++			  "to save IAADDR option");
++		status = ISC_R_FAILURE;
++		goto cleanup;
++	}
++
++	reply->resources_included = ISC_TRUE;
++
++      cleanup:
++	if (data.data != NULL)
++		data_string_forget(&data, MDL);
++
++	return status;
++}
++
++/* Choose the better of two leases. */
++static struct iasubopt *
++lease_compare(struct iasubopt *alpha, struct iasubopt *beta) {
++	if (alpha == NULL)
++		return beta;
++	if (beta == NULL)
++		return alpha;
++
++	switch(alpha->state) {
++	      case FTS_ACTIVE:
++		switch(beta->state) {
++		      case FTS_ACTIVE:
++			/* Choose the lease with the longest lifetime (most
++			 * likely the most recently allocated).
++			 */
++			if (alpha->hard_lifetime_end_time < 
++			    beta->hard_lifetime_end_time)
++				return beta;
++			else
++				return alpha;
++
++		      case FTS_EXPIRED:
++		      case FTS_ABANDONED:
++			return alpha;
++
++		      default:
++			log_fatal("Impossible condition at %s:%d.", MDL);
++		}
++		break;
++
++	      case FTS_EXPIRED:
++		switch (beta->state) {
++		      case FTS_ACTIVE:
++			return beta;
++
++		      case FTS_EXPIRED:
++			/* Choose the most recently expired lease. */
++			if (alpha->hard_lifetime_end_time <
++			    beta->hard_lifetime_end_time)
++				return beta;
++			else if ((alpha->hard_lifetime_end_time ==
++				  beta->hard_lifetime_end_time) &&
++				 (alpha->soft_lifetime_end_time <
++				  beta->soft_lifetime_end_time))
++				return beta;
++			else
++				return alpha;
++
++		      case FTS_ABANDONED:
++			return alpha;
++
++		      default:
++			log_fatal("Impossible condition at %s:%d.", MDL);
++		}
++		break;
++
++	      case FTS_ABANDONED:
++		switch (beta->state) {
++		      case FTS_ACTIVE:
++		      case FTS_EXPIRED:
++			return alpha;
++
++		      case FTS_ABANDONED:
++			/* Choose the lease that was abandoned longest ago. */
++			if (alpha->hard_lifetime_end_time <
++			    beta->hard_lifetime_end_time)
++				return alpha;
++
++		      default:
++			log_fatal("Impossible condition at %s:%d.", MDL);
++		}
++		break;
++
++	      default:
++		log_fatal("Impossible condition at %s:%d.", MDL);
++	}
++
++	log_fatal("Triple impossible condition at %s:%d.", MDL);
++	return NULL;
++}
++
++/* Process a client-supplied IA_PD.  This may append options to the tail of
++ * the reply packet being built in the reply_state structure.
++ */
++static isc_result_t
++reply_process_ia_pd(struct reply_state *reply, struct option_cache *ia) {
++	isc_result_t status = ISC_R_SUCCESS;
++	u_int32_t iaid;
++	unsigned ia_cursor;
++	struct option_state *packet_ia;
++	struct option_cache *oc;
++	struct data_string ia_data, data;
++
++	/* Initialize values that will get cleaned up on return. */
++	packet_ia = NULL;
++	memset(&ia_data, 0, sizeof(ia_data));
++	memset(&data, 0, sizeof(data));
++	/* 
++	 * Note that find_client_prefix() may set reply->lease.
++	 */
++
++	/* Make sure there is at least room for the header. */
++	if ((reply->cursor + IA_PD_OFFSET + 4) > sizeof(reply->buf)) {
++		log_error("reply_process_ia_pd: Reply too long for IA.");
++		return ISC_R_NOSPACE;
++	}
++
++
++	/* Fetch the IA_PD contents. */
++	if (!get_encapsulated_IA_state(&packet_ia, &ia_data, reply->packet,
++				       ia, IA_PD_OFFSET)) {
++		log_error("reply_process_ia_pd: error evaluating ia");
++		status = ISC_R_FAILURE;
++		goto cleanup;
++	}
++
++	/* Extract IA_PD header contents. */
++	iaid = getULong(ia_data.data);
++	reply->renew = getULong(ia_data.data + 4);
++	reply->rebind = getULong(ia_data.data + 8);
++
++	/* Create an IA_PD structure. */
++	if (ia_allocate(&reply->ia, iaid, (char *)reply->client_id.data, 
++			reply->client_id.len, MDL) != ISC_R_SUCCESS) {
++		log_error("reply_process_ia_pd: no memory for ia.");
++		status = ISC_R_NOMEMORY;
++		goto cleanup;
++	}
++	reply->ia->ia_type = D6O_IA_PD;
++
++	/* Cache pre-existing IA_PD, if any. */
++	ia_hash_lookup(&reply->old_ia, ia_pd_active,
++		       (unsigned char *)reply->ia->iaid_duid.data,
++		       reply->ia->iaid_duid.len, MDL);
++
++	/*
++	 * Create an option cache to carry the IA_PD option contents, and
++	 * execute any user-supplied values into it.
++	 */
++	if (!option_state_allocate(&reply->reply_ia, MDL)) {
++		status = ISC_R_NOMEMORY;
++		goto cleanup;
++	}
++
++	/* Check & count the fixed prefix host records. */
++	reply->static_prefixes = 0;
++	if ((reply->host != NULL) && (reply->host->fixed_prefix != NULL)) {
++		struct iaddrcidrnetlist *fp;
++
++		for (fp = reply->host->fixed_prefix; fp != NULL;
++		     fp = fp->next) {
++			reply->static_prefixes += 1;
++		}
++	}
++
++	/*
++	 * Save the cursor position at the start of the IA_PD, so we can
++	 * set length and adjust t1/t2 values later.  We write a temporary
++	 * header out now just in case we decide to adjust the packet
++	 * within sub-process functions.
++	 */
++	ia_cursor = reply->cursor;
++
++	/* Initialize the IA_PD header.  First the code. */
++	putUShort(reply->buf.data + reply->cursor, (unsigned)D6O_IA_PD);
++	reply->cursor += 2;
++
++	/* Then option length. */
++	putUShort(reply->buf.data + reply->cursor, 0x0Cu);
++	reply->cursor += 2;
++
++	/* Then IA_PD header contents; IAID. */
++	putULong(reply->buf.data + reply->cursor, iaid);
++	reply->cursor += 4;
++
++	/* We store the client's t1 for now, and may over-ride it later. */
++	putULong(reply->buf.data + reply->cursor, reply->renew);
++	reply->cursor += 4;
++
++	/* We store the client's t2 for now, and may over-ride it later. */
++	putULong(reply->buf.data + reply->cursor, reply->rebind);
++	reply->cursor += 4;
++
++	/* 
++	 * For each prefix in this IA_PD, decide what to do about it.
++	 */
++	oc = lookup_option(&dhcpv6_universe, packet_ia, D6O_IAPREFIX);
++	reply->valid = reply->prefer = 0xffffffff;
++	reply->client_valid = reply->client_prefer = 0;
++	reply->preflen = -1;
++	for (; oc != NULL ; oc = oc->next) {
++		status = reply_process_prefix(reply, oc);
++
++		/*
++		 * Canceled means we did not allocate prefixes to the
++		 * client, but we're "done" with this IA - we set a status
++		 * code.  So transmit this reply, e.g., move on to the next
++		 * IA.
++		 */
++		if (status == ISC_R_CANCELED)
++			break;
++
++		if ((status != ISC_R_SUCCESS) && (status != ISC_R_ADDRINUSE))
++			goto cleanup;
++	}
++
++	reply->pd_count++;
++
++	/*
++	 * If we fell through the above and never gave the client
++	 * a prefix, give it one now.
++	 */
++	if ((status != ISC_R_CANCELED) && (reply->client_resources == 0)) {
++		status = find_client_prefix(reply);
++
++		if (status == ISC_R_NORESOURCES) {
++			switch (reply->packet->dhcpv6_msg_type) {
++			      case DHCPV6_SOLICIT:
++				/*
++				 * No prefix for any IA is handled
++				 * by the caller.
++				 */
++				/* FALL THROUGH */
++
++			      case DHCPV6_REQUEST:
++				/* Same than for addresses. */
++				option_state_dereference(&reply->reply_ia, MDL);
++				if (!option_state_allocate(&reply->reply_ia,
++							   MDL))
++				{
++					log_error("reply_process_ia_pd: No "
++						  "memory for option state "
++						  "wipe.");
++					status = ISC_R_NOMEMORY;
++					goto cleanup;
++				}
++
++				if (!set_status_code(STATUS_NoPrefixAvail,
++						     "No prefixes available "
++						     "for this interface.",
++						      reply->reply_ia)) {
++					log_error("reply_process_ia_pd: "
++						  "Unable to set "
++						  "NoPrefixAvail status "
++						  "code.");
++					status = ISC_R_FAILURE;
++					goto cleanup;
++				}
++
++				status = ISC_R_SUCCESS;
++				break;
++
++			      default:
++				if (reply->resources_included)
++					status = ISC_R_SUCCESS;
++				else
++					goto cleanup;
++				break;
++			}
++		}
++
++		if (status != ISC_R_SUCCESS)
++			goto cleanup;
++	}
++
++	reply->cursor += store_options6((char *)reply->buf.data + reply->cursor,
++					sizeof(reply->buf) - reply->cursor,
++					reply->reply_ia, reply->packet,
++					required_opts_IA_PD, NULL);
++
++	/* Reset the length of this IA_PD to match what was just written. */
++	putUShort(reply->buf.data + ia_cursor + 2,
++		  reply->cursor - (ia_cursor + 4));
++
++	/*
++	 * T1/T2 time selection is kind of weird.  We actually use DHCP
++	 * (v4) scoped options as handy existing places where these might
++	 * be configured by an administrator.  A value of zero tells the
++	 * client it may choose its own renewal time.
++	 */
++	reply->renew = 0;
++	oc = lookup_option(&dhcp_universe, reply->opt_state,
++			   DHO_DHCP_RENEWAL_TIME);
++	if (oc != NULL) {
++		if (!evaluate_option_cache(&data, reply->packet, NULL, NULL,
++					   reply->packet->options,
++					   reply->opt_state, &global_scope,
++					   oc, MDL) ||
++		    (data.len != 4)) {
++			log_error("Invalid renewal time.");
++		} else {
++			reply->renew = getULong(data.data);
++		}
++
++		if (data.data != NULL)
++			data_string_forget(&data, MDL);
++	}
++	putULong(reply->buf.data + ia_cursor + 8, reply->renew);
++
++	/* Now T2. */
++	reply->rebind = 0;
++	oc = lookup_option(&dhcp_universe, reply->opt_state,
++			   DHO_DHCP_REBINDING_TIME);
++	if (oc != NULL) {
++		if (!evaluate_option_cache(&data, reply->packet, NULL, NULL,
++					   reply->packet->options,
++					   reply->opt_state, &global_scope,
++					   oc, MDL) ||
++		    (data.len != 4)) {
++			log_error("Invalid rebinding time.");
++		} else {
++			reply->rebind = getULong(data.data);
++		}
++
++		if (data.data != NULL)
++			data_string_forget(&data, MDL);
++	}
++	putULong(reply->buf.data + ia_cursor + 12, reply->rebind);
++
++	/*
++	 * If this is not a 'soft' binding, consume the new changes into
++	 * the database (if any have been attached to the ia_pd).
++	 *
++	 * Loop through the assigned dynamic prefixes, referencing the
++	 * prefixes onto this IA_PD rather than any old ones, and updating
++	 * prefix pool timers for each (if any).
++	 */
++	if ((status != ISC_R_CANCELED) && (reply->static_prefixes == 0) &&
++	    (reply->buf.reply.msg_type == DHCPV6_REPLY) &&
++	    (reply->ia->num_iasubopt != 0)) {
++		struct iasubopt *tmp;
++		struct data_string *ia_id;
++		int i;
++
++		for (i = 0 ; i < reply->ia->num_iasubopt ; i++) {
++			tmp = reply->ia->iasubopt[i];
++
++			if (tmp->ia != NULL)
++				ia_dereference(&tmp->ia, MDL);
++			ia_reference(&tmp->ia, reply->ia, MDL);
++
++			/* Commit 'hard' bindings. */
++			tmp->hard_lifetime_end_time =
++				tmp->soft_lifetime_end_time;
++			tmp->soft_lifetime_end_time = 0;
++			renew_lease6(tmp->ipv6_pool, tmp);
++			schedule_lease_timeout(tmp->ipv6_pool);
++		}
++
++		/* Remove any old ia from the hash. */
++		if (reply->old_ia != NULL) {
++			ia_id = &reply->old_ia->iaid_duid;
++			ia_hash_delete(ia_pd_active,
++				       (unsigned char *)ia_id->data,
++				       ia_id->len, MDL);
++			ia_dereference(&reply->old_ia, MDL);
++		}
++
++		/* Put new ia into the hash. */
++		reply->ia->cltt = cur_time;
++		ia_id = &reply->ia->iaid_duid;
++		ia_hash_add(ia_pd_active, (unsigned char *)ia_id->data,
++			    ia_id->len, reply->ia, MDL);
++
++		write_ia(reply->ia);
++	}
++
++      cleanup:
++	if (packet_ia != NULL)
++		option_state_dereference(&packet_ia, MDL);
++	if (reply->reply_ia != NULL)
++		option_state_dereference(&reply->reply_ia, MDL);
++	if (ia_data.data != NULL)
++		data_string_forget(&ia_data, MDL);
++	if (data.data != NULL)
++		data_string_forget(&data, MDL);
++	if (reply->ia != NULL)
++		ia_dereference(&reply->ia, MDL);
++	if (reply->old_ia != NULL)
++		ia_dereference(&reply->old_ia, MDL);
++	if (reply->lease != NULL)
++		iasubopt_dereference(&reply->lease, MDL);
++
++	/*
++	 * ISC_R_CANCELED is a status code used by the prefix processing to
++	 * indicate we're replying with a status code.  This is still a
++	 * success at higher layers.
++	 */
++	return((status == ISC_R_CANCELED) ? ISC_R_SUCCESS : status);
++}
++
++/*
++ * Process an IAPREFIX within a given IA_PD, storing any IAPREFIX reply
++ * contents into the reply's current ia_pd-scoped option cache.  Returns
++ * ISC_R_CANCELED in the event we are replying with a status code and do
++ * not wish to process more IAPREFIXes within this IA_PD.
++ */
++static isc_result_t
++reply_process_prefix(struct reply_state *reply, struct option_cache *pref) {
++	u_int32_t pref_life, valid_life;
++	struct binding_scope **scope;
++	struct iaddrcidrnet tmp_pref;
++	struct option_cache *oc;
++	struct data_string iapref, data;
++	isc_result_t status = ISC_R_SUCCESS;
++
++	/* Initializes values that will be cleaned up. */
++	memset(&iapref, 0, sizeof(iapref));
++	memset(&data, 0, sizeof(data));
++	/* Note that reply->lease may be set by prefix_is_owned() */
++
++	/*
++	 * There is no point trying to process an incoming prefix if there
++	 * is no room for an outgoing prefix.
++	 */
++	if ((reply->cursor + 29) > sizeof(reply->buf)) {
++		log_error("reply_process_prefix: Out of room for prefix.");
++		return ISC_R_NOSPACE;
++	}
++
++	/* Extract this IAPREFIX option. */
++	if (!evaluate_option_cache(&iapref, reply->packet, NULL, NULL, 
++				   reply->packet->options, NULL, &global_scope,
++				   pref, MDL) ||
++	    (iapref.len < IAPREFIX_OFFSET)) {
++		log_error("reply_process_prefix: error evaluating IAPREFIX.");
++		status = ISC_R_FAILURE;
++		goto cleanup;
++	}
++
++	/*
++	 * Layout: preferred and valid lifetimes followed by the prefix
++	 * length and the IPv6 address.
++	 */
++	pref_life = getULong(iapref.data);
++	valid_life = getULong(iapref.data + 4);
++
++	if ((reply->client_valid == 0) ||
++	    (reply->client_valid > valid_life))
++		reply->client_valid = valid_life;
++
++	if ((reply->client_prefer == 0) ||
++	    (reply->client_prefer > pref_life))
++		reply->client_prefer = pref_life;
++
++	/* 
++	 * Clients may choose to send ::/0 as a prefix, with the idea to give
++	 * hints about preferred-lifetime or valid-lifetime.
++	 */
++	tmp_pref.lo_addr.len = 16;
++	memset(tmp_pref.lo_addr.iabuf, 0, 16);
++	if ((iapref.data[8] == 0) &&
++	    (memcmp(iapref.data + 9, tmp_pref.lo_addr.iabuf, 16) == 0)) {
++		/* Status remains success; we just ignore this one. */
++		goto cleanup;
++	}
++
++	/*
++	 * Clients may choose to send ::/X as a prefix to specify a
++	 * preferred/requested prefix length. Note X is never zero here.
++	 */
++	tmp_pref.bits = (int) iapref.data[8];
++	if (reply->preflen < 0) {
++		/* Cache the first preferred prefix length. */
++		reply->preflen = tmp_pref.bits;
++	}
++	if (memcmp(iapref.data + 9, tmp_pref.lo_addr.iabuf, 16) == 0) {
++		goto cleanup;
++	}
++
++	memcpy(tmp_pref.lo_addr.iabuf, iapref.data + 9, 16);
++
++	/* Verify the prefix belongs to the client. */
++	if (!prefix_is_owned(reply, &tmp_pref)) {
++		/* Same than for addresses. */
++		if ((reply->packet->dhcpv6_msg_type == DHCPV6_SOLICIT) ||
++		    (reply->packet->dhcpv6_msg_type == DHCPV6_REQUEST) ||
++		    (reply->packet->dhcpv6_msg_type == DHCPV6_REBIND)) {
++			status = reply_process_try_prefix(reply, &tmp_pref);
++
++			/* Either error out or skip this prefix. */
++			if ((status != ISC_R_SUCCESS) && 
++			    (status != ISC_R_ADDRINUSE)) 
++				goto cleanup;
++
++			if (reply->lease == NULL) {
++				if (reply->packet->dhcpv6_msg_type ==
++							DHCPV6_REBIND) {
++					reply->send_prefer = 0;
++					reply->send_valid = 0;
++					goto send_pref;
++				}
++
++				/* status remains success - ignore */
++				goto cleanup;
++			}
++		/*
++		 * RFC3633 section 18.2.3:
++		 *
++		 * If the delegating router cannot find a binding
++		 * for the requesting router's IA_PD the delegating
++		 * router returns the IA_PD containing no prefixes
++		 * with a Status Code option set to NoBinding in the
++		 * Reply message.
++		 *
++		 * On mismatch we (ab)use this pretending we have not the IA
++		 * as soon as we have not a prefix.
++		 */
++		} else if (reply->packet->dhcpv6_msg_type == DHCPV6_RENEW) {
++			/* Rewind the IA_PD to empty. */
++			option_state_dereference(&reply->reply_ia, MDL);
++			if (!option_state_allocate(&reply->reply_ia, MDL)) {
++				log_error("reply_process_prefix: No memory "
++					  "for option state wipe.");
++				status = ISC_R_NOMEMORY;
++				goto cleanup;
++			}
++
++			/* Append a NoBinding status code.  */
++			if (!set_status_code(STATUS_NoBinding,
++					     "Prefix not bound to this "
++					     "interface.", reply->reply_ia)) {
++				log_error("reply_process_prefix: Unable to "
++					  "attach status code.");
++				status = ISC_R_FAILURE;
++				goto cleanup;
++			}
++
++			/* Fin (no more IAPREFIXes). */
++			status = ISC_R_CANCELED;
++			goto cleanup;
++		} else {
++			log_error("It is impossible to lease a client that is "
++				  "not sending a solicit, request, renew, or "
++				  "rebind message.");
++			status = ISC_R_FAILURE;
++			goto cleanup;
++		}
++	}
++
++	if (reply->static_prefixes > 0) {
++		if (reply->host == NULL)
++			log_fatal("Impossible condition at %s:%d.", MDL);
++
++		scope = &global_scope;
++	} else {
++		if (reply->lease == NULL)
++			log_fatal("Impossible condition at %s:%d.", MDL);
++
++		scope = &reply->lease->scope;
++	}
++
++	/*
++	 * If client_resources is nonzero, then the reply_process_is_prefixed
++	 * function has executed configuration state into the reply option
++	 * cache.  We will use that valid cache to derive configuration for
++	 * whether or not to engage in additional prefixes, and similar.
++	 */
++	if (reply->client_resources != 0) {
++		unsigned limit = 1;
++
++		/*
++		 * Does this client have "enough" prefixes already?  Default
++		 * to one.  Everybody gets one, and one should be enough for
++		 * anybody.
++		 */
++		oc = lookup_option(&server_universe, reply->opt_state,
++				   SV_LIMIT_PREFS_PER_IA);
++		if (oc != NULL) {
++			if (!evaluate_option_cache(&data, reply->packet,
++						   NULL, NULL,
++						   reply->packet->options,
++						   reply->opt_state,
++						   scope, oc, MDL) ||
++			    (data.len != 4)) {
++				log_error("reply_process_prefix: unable to "
++					  "evaluate prefs-per-ia value.");
++				status = ISC_R_FAILURE;
++				goto cleanup;
++			}
++
++			limit = getULong(data.data);
++			data_string_forget(&data, MDL);
++		}
++
++		/*
++		 * If we wish to limit the client to a certain number of
++		 * prefixes, then omit the prefix from the reply.
++		 */
++		if (reply->client_resources >= limit)
++			goto cleanup;
++	}
++
++	status = reply_process_is_prefixed(reply, scope, reply->shared->group);
++	if (status != ISC_R_SUCCESS)
++		goto cleanup;
++
++      send_pref:
++	status = reply_process_send_prefix(reply, &tmp_pref);
++
++      cleanup:
++	if (iapref.data != NULL)
++		data_string_forget(&iapref, MDL);
++	if (data.data != NULL)
++		data_string_forget(&data, MDL);
++	if (reply->lease != NULL)
++		iasubopt_dereference(&reply->lease, MDL);
++
++	return status;
++}
++
++/*
++ * Verify the prefix belongs to the client.  If we've got a host
++ * record with fixed prefixes, it has to be an assigned prefix
++ * (fault out all else).  Otherwise it's a dynamic prefix, so lookup
++ * that prefix and make sure it belongs to this DUID:IAID pair.
++ */
++static isc_boolean_t
++prefix_is_owned(struct reply_state *reply, struct iaddrcidrnet *pref) {
++	struct iaddrcidrnetlist *l;
++	int i;
++
++	/*
++	 * This faults out prefixes that don't match fixed prefixes.
++	 */
++	if (reply->static_prefixes > 0) {
++		for (l = reply->host->fixed_prefix; l != NULL; l = l->next) {
++			if ((pref->bits == l->cidrnet.bits) &&
++			    (memcmp(pref->lo_addr.iabuf,
++				    l->cidrnet.lo_addr.iabuf, 16) == 0))
++				return ISC_TRUE;
++		}
++		return ISC_FALSE;
++	}
++
++	if ((reply->old_ia == NULL) ||
++	    (reply->old_ia->num_iasubopt == 0))
++		return ISC_FALSE;
++
++	for (i = 0 ; i < reply->old_ia->num_iasubopt ; i++) {
++		struct iasubopt *tmp;
++
++		tmp = reply->old_ia->iasubopt[i];
++
++		if ((pref->bits == (int) tmp->plen) &&
++		    memcmp(pref->lo_addr.iabuf, &tmp->addr, 16) == 0) {
++			iasubopt_reference(&reply->lease, tmp, MDL);
++			return ISC_TRUE;
++		}
++	}
++
++	return ISC_FALSE;
++}
++
++/*
++ * This function only returns failure on 'hard' failures.  If it succeeds,
++ * it will leave a prefix structure behind.
++ */
++static isc_result_t
++reply_process_try_prefix(struct reply_state *reply,
++			 struct iaddrcidrnet *pref) {
++	isc_result_t status = ISC_R_NORESOURCES;
++	struct ipv6_pool *pool;
++	int i;
++	struct data_string data_pref;
++
++	if ((reply == NULL) || (reply->shared == NULL) ||
++	    (reply->shared->ipv6_pools == NULL) || (pref == NULL) ||
++	    (reply->lease != NULL))
++		return ISC_R_INVALIDARG;
++
++	memset(&data_pref, 0, sizeof(data_pref));
++	data_pref.len = 17;
++	if (!buffer_allocate(&data_pref.buffer, data_pref.len, MDL)) {
++		log_error("reply_process_try_prefix: out of memory.");
++		return ISC_R_NOMEMORY;
++	}
++	data_pref.data = data_pref.buffer->data;
++	data_pref.buffer->data[0] = (u_int8_t) pref->bits;
++	memcpy(data_pref.buffer->data + 1, pref->lo_addr.iabuf, 16);
++
++	for (i = 0 ; (pool = reply->shared->ipv6_pools[i]) != NULL ; i++) {
++		if (pool->pool_type != D6O_IA_PD)
++			continue;
++		status = try_client_v6_prefix(&reply->lease, pool,
++					      &data_pref);
++		if (status == ISC_R_SUCCESS)
++			break;
++	}
++
++	data_string_forget(&data_pref, MDL);
++	/* Return just the most recent status... */
++	return status;
++}
++
++/* Look around for a prefix to give the client.  First, look through the old
++ * IA_PD for prefixes we can extend.  Second, try to allocate a new prefix.
++ * Finally, actually add that prefix into the current reply IA_PD.
++ */
++static isc_result_t
++find_client_prefix(struct reply_state *reply) {
++	struct iaddrcidrnet send_pref;
++	isc_result_t status = ISC_R_NORESOURCES;
++	struct iasubopt *prefix, *best_prefix = NULL;
++	struct binding_scope **scope;
++	int i;
++
++	if (reply->static_prefixes > 0) {
++		struct iaddrcidrnetlist *l;
++
++		if (reply->host == NULL)
++			return ISC_R_INVALIDARG;
++
++		for (l = reply->host->fixed_prefix; l != NULL; l = l->next) {
++			if (l->cidrnet.bits == reply->preflen)
++				break;
++		}
++		if (l == NULL) {
++			/*
++			 * If no fixed prefix has the preferred length,
++			 * get the first one.
++			 */
++			l = reply->host->fixed_prefix;
++		}
++		memcpy(&send_pref, &l->cidrnet, sizeof(send_pref));
++
++		status = ISC_R_SUCCESS;
++		scope = &global_scope;
++		goto send_pref;
++	}
++
++	if (reply->old_ia != NULL)  {
++		for (i = 0 ; i < reply->old_ia->num_iasubopt ; i++) {
++			struct shared_network *candidate_shared;
++
++			prefix = reply->old_ia->iasubopt[i];
++			candidate_shared = prefix->ipv6_pool->shared_network;
++
++			/*
++			 * Consider this prefix if it is in a global pool or
++			 * if it is scoped in a pool under the client's shared
++			 * network.
++			 */
++			if (candidate_shared == NULL ||
++			    candidate_shared == reply->shared) {
++				best_prefix = prefix_compare(reply, prefix,
++							     best_prefix);
++			}
++		}
++	}
++
++	/* Try to pick a new prefix if we didn't find one, or if we found an
++	 * abandoned prefix.
++	 */
++	if ((best_prefix == NULL) || (best_prefix->state == FTS_ABANDONED)) {
++		status = pick_v6_prefix(&reply->lease, reply->preflen,
++					reply->shared, &reply->client_id);
++	} else if (best_prefix != NULL) {
++		iasubopt_reference(&reply->lease, best_prefix, MDL);
++		status = ISC_R_SUCCESS;
++	}
++
++	/* Pick the abandoned prefix as a last resort. */
++	if ((status == ISC_R_NORESOURCES) && (best_prefix != NULL)) {
++		/* I don't see how this is supposed to be done right now. */
++		log_error("Reclaiming abandoned prefixes is not yet "
++			  "supported.  Treating this as an out of space "
++			  "condition.");
++		/* iasubopt_reference(&reply->lease, best_prefix, MDL); */
++	}
++
++	/* Give up now if we didn't find a prefix. */
++	if (status != ISC_R_SUCCESS)
++		return status;
++
++	if (reply->lease == NULL)
++		log_fatal("Impossible condition at %s:%d.", MDL);
++
++	scope = &reply->lease->scope;
++
++	send_pref.lo_addr.len = 16;
++	memcpy(send_pref.lo_addr.iabuf, &reply->lease->addr, 16);
++	send_pref.bits = (int) reply->lease->plen;
++
++      send_pref:
++	status = reply_process_is_prefixed(reply, scope, reply->shared->group);
++	if (status != ISC_R_SUCCESS)
++		return status;
++
++	status = reply_process_send_prefix(reply, &send_pref);
++	return status;
++}
++
++/* Once a prefix is found for a client, perform several common functions;
++ * Calculate and store valid and preferred prefix times, draw client options
++ * into the option state.
++ */
++static isc_result_t
++reply_process_is_prefixed(struct reply_state *reply,
++			  struct binding_scope **scope, struct group *group)
++{
++	isc_result_t status = ISC_R_SUCCESS;
++	struct data_string data;
++	struct option_cache *oc;
++
++	/* Initialize values we will cleanup. */
++	memset(&data, 0, sizeof(data));
++
++	/*
++	 * Bring configured options into the root packet level cache - start
++	 * with the lease's closest enclosing group (passed in by the caller
++	 * as 'group').
++	 */
++	execute_statements_in_scope(NULL, reply->packet, NULL, NULL,
++				    reply->packet->options, reply->opt_state,
++				    scope, group, root_group);
++
++	/*
++	 * If there is a host record, over-ride with values configured there,
++	 * without re-evaluating configuration from the previously executed
++	 * group or its common enclosers.
++	 */
++	if (reply->host != NULL)
++		execute_statements_in_scope(NULL, reply->packet, NULL, NULL,
++					    reply->packet->options,
++					    reply->opt_state, scope,
++					    reply->host->group, group);
++
++	/* Determine valid lifetime. */
++	if (reply->client_valid == 0)
++		reply->send_valid = DEFAULT_DEFAULT_LEASE_TIME;
++	else
++		reply->send_valid = reply->client_valid;
++
++	oc = lookup_option(&server_universe, reply->opt_state,
++			   SV_DEFAULT_LEASE_TIME);
++	if (oc != NULL) {
++		if (!evaluate_option_cache(&data, reply->packet, NULL, NULL,
++					   reply->packet->options,
++					   reply->opt_state,
++					   scope, oc, MDL) ||
++		    (data.len != 4)) {
++			log_error("reply_process_is_prefixed: unable to "
++				  "evaluate default prefix time");
++			status = ISC_R_FAILURE;
++			goto cleanup;
++		}
++
++		reply->send_valid = getULong(data.data);
++		data_string_forget(&data, MDL);
++	}
++
++	if (reply->client_prefer == 0)
++		reply->send_prefer = reply->send_valid;
++	else
++		reply->send_prefer = reply->client_prefer;
++
++	if (reply->send_prefer >= reply->send_valid)
++		reply->send_prefer = (reply->send_valid / 2) +
++				     (reply->send_valid / 8);
++
++	oc = lookup_option(&server_universe, reply->opt_state,
++			   SV_PREFER_LIFETIME);
++	if (oc != NULL) {
++		if (!evaluate_option_cache(&data, reply->packet, NULL, NULL,
++					   reply->packet->options,
++					   reply->opt_state,
++					   scope, oc, MDL) ||
++		    (data.len != 4)) {
++			log_error("reply_process_is_prefixed: unable to "
++				  "evaluate preferred prefix time");
++			status = ISC_R_FAILURE;
++			goto cleanup;
++		}
++
++		reply->send_prefer = getULong(data.data);
++		data_string_forget(&data, MDL);
++	}
++
++	/* Note lowest values for later calculation of renew/rebind times. */
++	if (reply->prefer > reply->send_prefer)
++		reply->prefer = reply->send_prefer;
++
++	if (reply->valid > reply->send_valid)
++		reply->valid = reply->send_valid;
++
++	/* Perform dynamic prefix related update work. */
++	if (reply->lease != NULL) {
++		/* Cached lifetimes */
++		reply->lease->prefer = reply->send_prefer;
++		reply->lease->valid = reply->send_valid;
++
++		/* Advance (or rewind) the valid lifetime. */
++		if (reply->buf.reply.msg_type == DHCPV6_REPLY) {
++			reply->lease->soft_lifetime_end_time =
++				cur_time + reply->send_valid;
++			/* Wait before renew! */
++		}
++
++		status = ia_add_iasubopt(reply->ia, reply->lease, MDL);
++		if (status != ISC_R_SUCCESS) {
++			log_fatal("reply_process_is_prefixed: Unable to "
++				  "attach prefix to new IA_PD: %s",
++				  isc_result_totext(status));
++		}
++
++		/*
++		 * If this is a new prefix, make sure it is attached somewhere.
++		 */
++		if (reply->lease->ia == NULL) {
++			ia_reference(&reply->lease->ia, reply->ia, MDL);
++		}
++	}
++
++	/* Bring a copy of the relevant options into the IA_PD scope. */
++	execute_statements_in_scope(NULL, reply->packet, NULL, NULL,
++				    reply->packet->options, reply->reply_ia,
++				    scope, group, root_group);
++
++	/*
++	 * And bring in host record configuration, if any, but not to overlap
++	 * the previous group or its common enclosers.
++	 */
++	if (reply->host != NULL)
++		execute_statements_in_scope(NULL, reply->packet, NULL, NULL,
++					    reply->packet->options,
++					    reply->reply_ia, scope,
++					    reply->host->group, group);
++
++      cleanup:
++	if (data.data != NULL)
++		data_string_forget(&data, MDL);
++
++	if (status == ISC_R_SUCCESS)
++		reply->client_resources++;
++
++	return status;
++}
++
++/* Simply send an IAPREFIX within the IA_PD scope as described. */
++static isc_result_t
++reply_process_send_prefix(struct reply_state *reply,
++			  struct iaddrcidrnet *pref) {
++	isc_result_t status = ISC_R_SUCCESS;
++	struct data_string data;
++
++	memset(&data, 0, sizeof(data));
++
++	/* Now append the prefix. */
++	data.len = IAPREFIX_OFFSET;
++	if (!buffer_allocate(&data.buffer, data.len, MDL)) {
++		log_error("reply_process_send_prefix: out of memory"
++			  "allocating new IAPREFIX buffer.");
++		status = ISC_R_NOMEMORY;
++		goto cleanup;
++	}
++	data.data = data.buffer->data;
++
++	putULong(data.buffer->data, reply->send_prefer);
++	putULong(data.buffer->data + 4, reply->send_valid);
++	data.buffer->data[8] = pref->bits;
++	memcpy(data.buffer->data + 9, pref->lo_addr.iabuf, 16);
++
++	if (!append_option_buffer(&dhcpv6_universe, reply->reply_ia,
++				  data.buffer, data.buffer->data,
++				  data.len, D6O_IAPREFIX, 0)) {
++		log_error("reply_process_send_prefix: unable "
++			  "to save IAPREFIX option");
++		status = ISC_R_FAILURE;
++		goto cleanup;
++	}
++
++	reply->resources_included = ISC_TRUE;
++
++      cleanup:
++	if (data.data != NULL)
++		data_string_forget(&data, MDL);
++
++	return status;
++}
++
++/* Choose the better of two prefixes. */
++static struct iasubopt *
++prefix_compare(struct reply_state *reply,
++	       struct iasubopt *alpha, struct iasubopt *beta) {
++	if (alpha == NULL)
++		return beta;
++	if (beta == NULL)
++		return alpha;
++
++	if (reply->preflen >= 0) {
++		if ((alpha->plen == reply->preflen) &&
++		    (beta->plen != reply->preflen))
++			return alpha;
++		if ((beta->plen == reply->preflen) &&
++		    (alpha->plen != reply->preflen))
++			return beta;
++	}
++
++	switch(alpha->state) {
++	      case FTS_ACTIVE:
++		switch(beta->state) {
++		      case FTS_ACTIVE:
++			/* Choose the prefix with the longest lifetime (most
++			 * likely the most recently allocated).
++			 */
++			if (alpha->hard_lifetime_end_time < 
++			    beta->hard_lifetime_end_time)
++				return beta;
++			else
++				return alpha;
++
++		      case FTS_EXPIRED:
++		      case FTS_ABANDONED:
++			return alpha;
++
++		      default:
++			log_fatal("Impossible condition at %s:%d.", MDL);
++		}
++		break;
++
++	      case FTS_EXPIRED:
++		switch (beta->state) {
++		      case FTS_ACTIVE:
++			return beta;
++
++		      case FTS_EXPIRED:
++			/* Choose the most recently expired prefix. */
++			if (alpha->hard_lifetime_end_time <
++			    beta->hard_lifetime_end_time)
++				return beta;
++			else if ((alpha->hard_lifetime_end_time ==
++				  beta->hard_lifetime_end_time) &&
++				 (alpha->soft_lifetime_end_time <
++				  beta->soft_lifetime_end_time))
++				return beta;
++			else
++				return alpha;
++
++		      case FTS_ABANDONED:
++			return alpha;
++
++		      default:
++			log_fatal("Impossible condition at %s:%d.", MDL);
++		}
++		break;
++
++	      case FTS_ABANDONED:
++		switch (beta->state) {
++		      case FTS_ACTIVE:
++		      case FTS_EXPIRED:
++			return alpha;
++
++		      case FTS_ABANDONED:
++			/* Choose the prefix that was abandoned longest ago. */
++			if (alpha->hard_lifetime_end_time <
++			    beta->hard_lifetime_end_time)
++				return alpha;
++
++		      default:
++			log_fatal("Impossible condition at %s:%d.", MDL);
++		}
++		break;
++
++	      default:
++		log_fatal("Impossible condition at %s:%d.", MDL);
++	}
++
++	log_fatal("Triple impossible condition at %s:%d.", MDL);
++	return NULL;
++}
++
++/*
++ * Solicit is how a client starts requesting addresses.
++ *
++ * If the client asks for rapid commit, and we support it, we will 
++ * allocate the addresses and reply.
++ *
++ * Otherwise we will send an advertise message.
++ */
++
++static void
++dhcpv6_solicit(struct data_string *reply_ret, struct packet *packet) {
++	struct data_string client_id;
++
++	/* 
++	 * Validate our input.
++	 */
++	if (!valid_client_msg(packet, &client_id)) {
++		return;
++	}
++
++	lease_to_client(reply_ret, packet, &client_id, NULL);
++
++	/*
++	 * Clean up.
++	 */
++	data_string_forget(&client_id, MDL);
++}
++
++/*
++ * Request is how a client actually requests addresses.
++ *
++ * Very similar to Solicit handling, except the server DUID is required.
++ */
++
++/* TODO: reject unicast messages, unless we set unicast option */
++static void
++dhcpv6_request(struct data_string *reply_ret, struct packet *packet) {
++	struct data_string client_id;
++	struct data_string server_id;
++
++	/*
++	 * Validate our input.
++	 */
++	if (!valid_client_resp(packet, &client_id, &server_id)) {
++		return;
++	}
++
++	/*
++	 * Issue our lease.
++	 */
++	lease_to_client(reply_ret, packet, &client_id, &server_id);
++
++	/*
++	 * Cleanup.
++	 */
++	data_string_forget(&client_id, MDL);
++	data_string_forget(&server_id, MDL);
++}
++
++/* Find a DHCPv6 packet's shared network from hints in the packet.
++ */
++static isc_result_t
++shared_network_from_packet6(struct shared_network **shared,
++			    struct packet *packet)
++{
++	const struct packet *chk_packet;
++	const struct in6_addr *link_addr, *first_link_addr;
++	struct iaddr tmp_addr;
++	struct subnet *subnet;
++	isc_result_t status;
++
++	if ((shared == NULL) || (*shared != NULL) || (packet == NULL))
++		return ISC_R_INVALIDARG;
++
++	/*
++	 * First, find the link address where the packet from the client
++	 * first appeared (if this packet was relayed).
++	 */
++	first_link_addr = NULL;
++	chk_packet = packet->dhcpv6_container_packet;
++	while (chk_packet != NULL) {
++		link_addr = &chk_packet->dhcpv6_link_address;
++		if (!IN6_IS_ADDR_UNSPECIFIED(link_addr) &&
++		    !IN6_IS_ADDR_LINKLOCAL(link_addr)) {
++			first_link_addr = link_addr;
++			break;
++		}
++		chk_packet = chk_packet->dhcpv6_container_packet;
++	}
++
++	/*
++	 * If there is a relayed link address, find the subnet associated
++	 * with that, and use that to get the appropriate
++	 * shared_network.
++	 */
++	if (first_link_addr != NULL) {
++		tmp_addr.len = sizeof(*first_link_addr);
++		memcpy(tmp_addr.iabuf,
++		       first_link_addr, sizeof(*first_link_addr));
++		subnet = NULL;
++		if (!find_subnet(&subnet, tmp_addr, MDL)) {
++			log_debug("No subnet found for link-address %s.",
++				  piaddr(tmp_addr));
++			return ISC_R_NOTFOUND;
++		}
++		status = shared_network_reference(shared,
++						  subnet->shared_network, MDL);
++		subnet_dereference(&subnet, MDL);
++
++	/*
++	 * If there is no link address, we will use the interface
++	 * that this packet came in on to pick the shared_network.
++	 */
++	} else {
++		status = shared_network_reference(shared,
++					 packet->interface->shared_network,
++					 MDL);
++	}
++
++	return status;
++}
++
++/*
++ * When a client thinks it might be on a new link, it sends a 
++ * Confirm message.
++ *
++ * From RFC3315 section 18.2.2:
++ *
++ *   When the server receives a Confirm message, the server determines
++ *   whether the addresses in the Confirm message are appropriate for the
++ *   link to which the client is attached.  If all of the addresses in the
++ *   Confirm message pass this test, the server returns a status of
++ *   Success.  If any of the addresses do not pass this test, the server
++ *   returns a status of NotOnLink.  If the server is unable to perform
++ *   this test (for example, the server does not have information about
++ *   prefixes on the link to which the client is connected), or there were
++ *   no addresses in any of the IAs sent by the client, the server MUST
++ *   NOT send a reply to the client.
++ */
++
++static void
++dhcpv6_confirm(struct data_string *reply_ret, struct packet *packet) {
++	struct shared_network *shared;
++	struct subnet *subnet;
++	struct option_cache *ia, *ta, *oc;
++	struct data_string cli_enc_opt_data, iaaddr, client_id, packet_oro;
++	struct option_state *cli_enc_opt_state, *opt_state;
++	struct iaddr cli_addr;
++	int pass;
++	isc_boolean_t inappropriate, has_addrs;
++	char reply_data[65536];
++	struct dhcpv6_packet *reply = (struct dhcpv6_packet *)reply_data;
++	int reply_ofs = (int)((char *)reply->options - (char *)reply);
++
++	/* 
++	 * Basic client message validation.
++	 */
++	memset(&client_id, 0, sizeof(client_id));
++	if (!valid_client_msg(packet, &client_id)) {
++		return;
++	}
++
++	/*
++	 * Do not process Confirms that do not have IA's we do not recognize.
++	 */
++	ia = lookup_option(&dhcpv6_universe, packet->options, D6O_IA_NA);
++	ta = lookup_option(&dhcpv6_universe, packet->options, D6O_IA_TA);
++	if ((ia == NULL) && (ta == NULL))
++		return;
++
++	/*
++	 * IA_PD's are simply ignored.
++	 */
++	delete_option(&dhcpv6_universe, packet->options, D6O_IA_PD);
++
++	/* 
++	 * Bit of variable initialization.
++	 */
++	opt_state = cli_enc_opt_state = NULL;
++	memset(&cli_enc_opt_data, 0, sizeof(cli_enc_opt_data));
++	memset(&iaaddr, 0, sizeof(iaaddr));
++	memset(&packet_oro, 0, sizeof(packet_oro));
++
++	/* Determine what shared network the client is connected to.  We
++	 * must not respond if we don't have any information about the
++	 * network the client is on.
++	 */
++	shared = NULL;
++	if ((shared_network_from_packet6(&shared, packet) != ISC_R_SUCCESS) ||
++	    (shared == NULL))
++		goto exit;
++
++	/* If there are no recorded subnets, then we have no
++	 * information about this subnet - ignore Confirms.
++	 */
++	subnet = shared->subnets;
++	if (subnet == NULL)
++		goto exit;
++
++	/* Are the addresses in all the IA's appropriate for that link? */
++	has_addrs = inappropriate = ISC_FALSE;
++	pass = D6O_IA_NA;
++	while(!inappropriate) {
++		/* If we've reached the end of the IA_NA pass, move to the
++		 * IA_TA pass.
++		 */
++		if ((pass == D6O_IA_NA) && (ia == NULL)) {
++			pass = D6O_IA_TA;
++			ia = ta;
++		}
++
++		/* If we've reached the end of all passes, we're done. */
++		if (ia == NULL)
++			break;
++
++		if (((pass == D6O_IA_NA) &&
++		     !get_encapsulated_IA_state(&cli_enc_opt_state,
++						&cli_enc_opt_data,
++						packet, ia, IA_NA_OFFSET)) ||
++		    ((pass == D6O_IA_TA) &&
++		     !get_encapsulated_IA_state(&cli_enc_opt_state,
++						&cli_enc_opt_data,
++						packet, ia, IA_TA_OFFSET))) {
++			goto exit;
++		}
++
++		oc = lookup_option(&dhcpv6_universe, cli_enc_opt_state,
++				   D6O_IAADDR);
++
++		for ( ; oc != NULL ; oc = oc->next) {
++			if (!evaluate_option_cache(&iaaddr, packet, NULL, NULL,
++						   packet->options, NULL,
++						   &global_scope, oc, MDL) ||
++			    (iaaddr.len < IAADDR_OFFSET)) {
++				log_error("dhcpv6_confirm: "
++					  "error evaluating IAADDR.");
++				goto exit;
++			}
++
++			/* Copy out the IPv6 address for processing. */
++			cli_addr.len = 16;
++			memcpy(cli_addr.iabuf, iaaddr.data, 16);
++
++			data_string_forget(&iaaddr, MDL);
++
++			/* Record that we've processed at least one address. */
++			has_addrs = ISC_TRUE;
++
++			/* Find out if any subnets cover this address. */
++			for (subnet = shared->subnets ; subnet != NULL ;
++			     subnet = subnet->next_sibling) {
++				if (addr_eq(subnet_number(cli_addr,
++							  subnet->netmask),
++					    subnet->net))
++					break;
++			}
++
++			/* If we reach the end of the subnet list, and no
++			 * subnet matches the client address, then it must
++			 * be inappropriate to the link (so far as our
++			 * configuration says).  Once we've found one
++			 * inappropriate address, there is no reason to
++			 * continue searching.
++			 */
++			if (subnet == NULL) {
++				inappropriate = ISC_TRUE;
++				break;
++			}
++		}
++
++		option_state_dereference(&cli_enc_opt_state, MDL);
++		data_string_forget(&cli_enc_opt_data, MDL);
++
++		/* Advance to the next IA_*. */
++		ia = ia->next;
++	}
++
++	/* If the client supplied no addresses, do not reply. */
++	if (!has_addrs)
++		goto exit;
++
++	/* 
++	 * Set up reply.
++	 */
++	if (!start_reply(packet, &client_id, NULL, &opt_state, reply)) {
++		goto exit;
++	}
++
++	/* 
++	 * Set our status.
++	 */
++	if (inappropriate) {
++		if (!set_status_code(STATUS_NotOnLink, 
++				     "Some of the addresses are not on link.",
++				     opt_state)) {
++			goto exit;
++		}
++	} else {
++		if (!set_status_code(STATUS_Success, 
++				     "All addresses still on link.",
++				     opt_state)) {
++			goto exit;
++		}
++	}
++
++	/* 
++	 * Only one option: add it.
++	 */
++	reply_ofs += store_options6(reply_data+reply_ofs,
++				    sizeof(reply_data)-reply_ofs, 
++				    opt_state, packet,
++				    required_opts, &packet_oro);
++
++	/* 
++	 * Return our reply to the caller.
++	 */
++	reply_ret->len = reply_ofs;
++	reply_ret->buffer = NULL;
++	if (!buffer_allocate(&reply_ret->buffer, reply_ofs, MDL)) {
++		log_fatal("No memory to store reply.");
++	}
++	reply_ret->data = reply_ret->buffer->data;
++	memcpy(reply_ret->buffer->data, reply, reply_ofs);
++
++exit:
++	/* Cleanup any stale data strings. */
++	if (cli_enc_opt_data.buffer != NULL)
++		data_string_forget(&cli_enc_opt_data, MDL);
++	if (iaaddr.buffer != NULL)
++		data_string_forget(&iaaddr, MDL);
++	if (client_id.buffer != NULL)
++		data_string_forget(&client_id, MDL);
++	if (packet_oro.buffer != NULL)
++		data_string_forget(&packet_oro, MDL);
++
++	/* Release any stale option states. */
++	if (cli_enc_opt_state != NULL)
++		option_state_dereference(&cli_enc_opt_state, MDL);
++	if (opt_state != NULL)
++		option_state_dereference(&opt_state, MDL);
++}
++
++/*
++ * Renew is when a client wants to extend its lease/prefix, at time T1.
++ *
++ * We handle this the same as if the client wants a new lease/prefix,
++ * except for the error code of when addresses don't match.
++ */
++
++/* TODO: reject unicast messages, unless we set unicast option */
++static void
++dhcpv6_renew(struct data_string *reply, struct packet *packet) {
++	struct data_string client_id;
++	struct data_string server_id;
++
++	/* 
++	 * Validate the request.
++	 */
++	if (!valid_client_resp(packet, &client_id, &server_id)) {
++		return;
++	}
++
++	/*
++	 * Renew our lease.
++	 */
++	lease_to_client(reply, packet, &client_id, &server_id);
++
++	/*
++	 * Cleanup.
++	 */
++	data_string_forget(&server_id, MDL);
++	data_string_forget(&client_id, MDL);
++}
++
++/*
++ * Rebind is when a client wants to extend its lease, at time T2.
++ *
++ * We handle this the same as if the client wants a new lease, except
++ * for the error code of when addresses don't match.
++ */
++
++static void
++dhcpv6_rebind(struct data_string *reply, struct packet *packet) {
++	struct data_string client_id;
++
++	if (!valid_client_msg(packet, &client_id)) {
++		return;
++	}
++
++	lease_to_client(reply, packet, &client_id, NULL);
++
++	data_string_forget(&client_id, MDL);
++}
++
++static void
++ia_na_match_decline(const struct data_string *client_id,
++		    const struct data_string *iaaddr,
++		    struct iasubopt *lease)
++{
++	char tmp_addr[INET6_ADDRSTRLEN];
++
++	log_error("Client %s reports address %s is "
++		  "already in use by another host!",
++		  print_hex_1(client_id->len, client_id->data, 60),
++		  inet_ntop(AF_INET6, iaaddr->data, 
++		  	    tmp_addr, sizeof(tmp_addr)));
++	if (lease != NULL) {
++		decline_lease6(lease->ipv6_pool, lease);
++		lease->ia->cltt = cur_time;
++		write_ia(lease->ia);
++	}
++}
++
++static void
++ia_na_nomatch_decline(const struct data_string *client_id,
++		      const struct data_string *iaaddr,
++		      u_int32_t *ia_na_id,
++		      struct packet *packet,
++		      char *reply_data,
++		      int *reply_ofs,
++		      int reply_len)
++{
++	char tmp_addr[INET6_ADDRSTRLEN];
++	struct option_state *host_opt_state;
++	int len;
++
++	log_info("Client %s declines address %s, which is not offered to it.",
++		 print_hex_1(client_id->len, client_id->data, 60),
++		 inet_ntop(AF_INET6, iaaddr->data, tmp_addr, sizeof(tmp_addr)));
++
++	/*
++	 * Create state for this IA_NA.
++	 */
++	host_opt_state = NULL;
++	if (!option_state_allocate(&host_opt_state, MDL)) {
++		log_error("ia_na_nomatch_decline: out of memory "
++			  "allocating option_state.");
++		goto exit;
++	}
++
++	if (!set_status_code(STATUS_NoBinding, "Decline for unknown address.",
++			     host_opt_state)) {
++		goto exit;
++	}
++
++	/*
++	 * Insure we have enough space
++	 */
++	if (reply_len < (*reply_ofs + 16)) {
++		log_error("ia_na_nomatch_decline: "
++			  "out of space for reply packet.");
++		goto exit;
++	}
++
++	/*
++	 * Put our status code into the reply packet.
++	 */
++	len = store_options6(reply_data+(*reply_ofs)+16,
++			     reply_len-(*reply_ofs)-16,
++			     host_opt_state, packet,
++			     required_opts_STATUS_CODE, NULL);
++
++	/*
++	 * Store the non-encapsulated option data for this 
++	 * IA_NA into our reply packet. Defined in RFC 3315, 
++	 * section 22.4.  
++	 */
++	/* option number */
++	putUShort((unsigned char *)reply_data+(*reply_ofs), D6O_IA_NA);
++	/* option length */
++	putUShort((unsigned char *)reply_data+(*reply_ofs)+2, len + 12);
++	/* IA_NA, copied from the client */
++	memcpy(reply_data+(*reply_ofs)+4, ia_na_id, 4);
++	/* t1 and t2, odd that we need them, but here it is */
++	putULong((unsigned char *)reply_data+(*reply_ofs)+8, 0);
++	putULong((unsigned char *)reply_data+(*reply_ofs)+12, 0);
++
++	/*
++	 * Get ready for next IA_NA.
++	 */
++	*reply_ofs += (len + 16);
++
++exit:
++	option_state_dereference(&host_opt_state, MDL);
++}
++
++static void
++iterate_over_ia_na(struct data_string *reply_ret, 
++		   struct packet *packet,
++		   const struct data_string *client_id,
++		   const struct data_string *server_id,
++		   const char *packet_type,
++		   void (*ia_na_match)(),
++		   void (*ia_na_nomatch)())
++{
++	struct option_state *opt_state;
++	struct host_decl *packet_host;
++	struct option_cache *ia;
++	struct option_cache *oc;
++	/* cli_enc_... variables come from the IA_NA/IA_TA options */
++	struct data_string cli_enc_opt_data;
++	struct option_state *cli_enc_opt_state;
++	struct host_decl *host;
++	struct option_state *host_opt_state;
++	struct data_string iaaddr;
++	struct data_string fixed_addr;
++	int iaaddr_is_found;
++	char reply_data[65536];
++	struct dhcpv6_packet *reply = (struct dhcpv6_packet *)reply_data;
++	int reply_ofs = (int)((char *)reply->options - (char *)reply);
++	char status_msg[32];
++	struct iasubopt *lease;
++	struct ia_xx *existing_ia_na;
++	int i;
++	struct data_string key;
++	u_int32_t iaid;
++
++	/*
++	 * Initialize to empty values, in case we have to exit early.
++	 */
++	opt_state = NULL;
++	memset(&cli_enc_opt_data, 0, sizeof(cli_enc_opt_data));
++	cli_enc_opt_state = NULL;
++	memset(&iaaddr, 0, sizeof(iaaddr));
++	memset(&fixed_addr, 0, sizeof(fixed_addr));
++	host_opt_state = NULL;
++	lease = NULL;
++
++	/* 
++	 * Find the host record that matches from the packet, if any.
++	 */
++	packet_host = NULL;
++	if (!find_hosts_by_uid(&packet_host, 
++			       client_id->data, client_id->len, MDL)) {
++		packet_host = NULL;
++		/* 
++		 * Note: In general, we don't expect a client to provide
++		 *       enough information to match by option for these
++		 *       types of messages, but if we don't have a UID
++		 *       match we can check anyway.
++		 */
++		if (!find_hosts_by_option(&packet_host, 
++					  packet, packet->options, MDL)) {
++			packet_host = NULL;
++		}
++	}
++
++	/* 
++	 * Set our reply information.
++	 */
++	reply->msg_type = DHCPV6_REPLY;
++	memcpy(reply->transaction_id, packet->dhcpv6_transaction_id, 
++	       sizeof(reply->transaction_id));
++
++	/*
++	 * Build our option state for reply.
++	 */
++	opt_state = NULL;
++	if (!option_state_allocate(&opt_state, MDL)) {
++		log_error("iterate_over_ia_na: no memory for option_state.");
++		goto exit;
++	}
++	execute_statements_in_scope(NULL, packet, NULL, NULL, 
++				    packet->options, opt_state, 
++				    &global_scope, root_group, NULL);
++
++	/* 
++	 * RFC 3315, section 18.2.7 tells us which options to include.
++	 */
++	oc = lookup_option(&dhcpv6_universe, opt_state, D6O_SERVERID);
++	if (oc == NULL) {
++		if (!save_option_buffer(&dhcpv6_universe, opt_state, NULL, 
++					(unsigned char *)server_duid.data, 
++					server_duid.len, D6O_SERVERID, 0)) {
++			log_error("iterate_over_ia_na: "
++				  "error saving server identifier.");
++			goto exit;
++		}
++	}
++
++	if (!save_option_buffer(&dhcpv6_universe, opt_state, 
++				client_id->buffer, 
++				(unsigned char *)client_id->data,
++				client_id->len, 
++				D6O_CLIENTID, 0)) {
++		log_error("iterate_over_ia_na: "
++			  "error saving client identifier.");
++		goto exit;
++	}
++
++	snprintf(status_msg, sizeof(status_msg), "%s received.", packet_type);
++	if (!set_status_code(STATUS_Success, status_msg, opt_state)) {
++		goto exit;
++	}
++
++	/* 
++	 * Add our options that are not associated with any IA_NA or IA_TA. 
++	 */
++	reply_ofs += store_options6(reply_data+reply_ofs,
++				    sizeof(reply_data)-reply_ofs, 
++				    opt_state, packet,
++				    required_opts, NULL);
++
++	/*
++	 * Loop through the IA_NA reported by the client, and deal with
++	 * addresses reported as already in use.
++	 */
++	for (ia = lookup_option(&dhcpv6_universe, packet->options, D6O_IA_NA);
++	     ia != NULL; ia = ia->next) {
++	     	iaaddr_is_found = 0;
++
++		if (!get_encapsulated_IA_state(&cli_enc_opt_state,
++					       &cli_enc_opt_data,
++					       packet, ia, IA_NA_OFFSET)) {
++			goto exit;
++		}
++
++		iaid = getULong(cli_enc_opt_data.data);
++
++		/* 
++		 * XXX: It is possible that we can get multiple addresses
++		 *      sent by the client. We don't send multiple 
++		 *      addresses, so this indicates a client error. 
++		 *      We should check for multiple IAADDR options, log
++		 *      if found, and set as an error.
++		 */
++		oc = lookup_option(&dhcpv6_universe, cli_enc_opt_state, 
++				   D6O_IAADDR);
++		if (oc == NULL) {
++			/* no address given for this IA, ignore */
++			option_state_dereference(&cli_enc_opt_state, MDL);
++			data_string_forget(&cli_enc_opt_data, MDL);
++			continue;
++		}
++
++		memset(&iaaddr, 0, sizeof(iaaddr));
++		if (!evaluate_option_cache(&iaaddr, packet, NULL, NULL, 
++					   packet->options, NULL,
++					   &global_scope, oc, MDL)) {
++			log_error("iterate_over_ia_na: "
++				  "error evaluating IAADDR.");
++			goto exit;
++		}
++
++		/* 
++		 * Now we need to figure out which host record matches
++		 * this IA_NA and IAADDR.
++		 *
++		 * XXX: We don't currently track IA_NA separately, but
++		 *      we will need to do this!
++		 */
++		host = NULL;
++		if (!find_hosts_by_option(&host, packet, 
++					  cli_enc_opt_state, MDL)) { 
++			if (packet_host != NULL) {
++				host = packet_host;
++			} else {
++				host = NULL;
++			}
++		}
++		while (host != NULL) {
++			if (host->fixed_addr != NULL) {
++				if (!evaluate_option_cache(&fixed_addr, NULL, 
++							   NULL, NULL, NULL, 
++							   NULL, &global_scope,
++							   host->fixed_addr, 
++							   MDL)) {
++					log_error("iterate_over_ia_na: error "
++						  "evaluating host address.");
++					goto exit;
++				}
++				if ((iaaddr.len >= 16) &&
++				    !memcmp(fixed_addr.data, iaaddr.data, 16)) {
++					data_string_forget(&fixed_addr, MDL);
++					break;
++				}
++				data_string_forget(&fixed_addr, MDL);
++			}
++			host = host->n_ipaddr;
++		}
++
++		if ((host == NULL) && (iaaddr.len >= IAADDR_OFFSET)) {
++			/*
++			 * Find existing IA_NA.
++			 */
++			if (ia_make_key(&key, iaid, 
++					(char *)client_id->data,
++					client_id->len, 
++					MDL) != ISC_R_SUCCESS) {
++				log_fatal("iterate_over_ia_na: no memory for "
++					  "key.");
++			}
++
++			existing_ia_na = NULL;
++			if (ia_hash_lookup(&existing_ia_na, ia_na_active, 
++					   (unsigned char *)key.data, 
++					   key.len, MDL)) {
++				/* 
++				 * Make sure this address is in the IA_NA.
++				 */
++				for (i=0; i<existing_ia_na->num_iasubopt; i++) {
++					struct iasubopt *tmp;
++					struct in6_addr *in6_addr;
++
++					tmp = existing_ia_na->iasubopt[i];
++					in6_addr = &tmp->addr;
++					if (memcmp(in6_addr, 
++						   iaaddr.data, 16) == 0) {
++						iasubopt_reference(&lease,
++								   tmp, MDL);
++						break;
++					}
++				}
++			}
++
++			data_string_forget(&key, MDL);
++		}
++
++		if ((host != NULL) || (lease != NULL)) {
++			ia_na_match(client_id, &iaaddr, lease);
++		} else {
++			ia_na_nomatch(client_id, &iaaddr, 
++				      (u_int32_t *)cli_enc_opt_data.data, 
++				      packet, reply_data, &reply_ofs, 
++				      sizeof(reply_data));
++		}
++
++		if (lease != NULL) {
++			iasubopt_dereference(&lease, MDL);
++		}
++
++		data_string_forget(&iaaddr, MDL);
++		option_state_dereference(&cli_enc_opt_state, MDL);
++		data_string_forget(&cli_enc_opt_data, MDL);
++	}
++
++	/* 
++	 * Return our reply to the caller.
++	 */
++	reply_ret->len = reply_ofs;
++	reply_ret->buffer = NULL;
++	if (!buffer_allocate(&reply_ret->buffer, reply_ofs, MDL)) {
++		log_fatal("No memory to store reply.");
++	}
++	reply_ret->data = reply_ret->buffer->data;
++	memcpy(reply_ret->buffer->data, reply, reply_ofs);
++
++exit:
++	if (lease != NULL) {
++		iasubopt_dereference(&lease, MDL);
++	}
++	if (host_opt_state != NULL) {
++		option_state_dereference(&host_opt_state, MDL);
++	}
++	if (fixed_addr.buffer != NULL) {
++		data_string_forget(&fixed_addr, MDL);
++	}
++	if (iaaddr.buffer != NULL) {
++		data_string_forget(&iaaddr, MDL);
++	}
++	if (cli_enc_opt_state != NULL) {
++		option_state_dereference(&cli_enc_opt_state, MDL);
++	}
++	if (cli_enc_opt_data.buffer != NULL) {
++		data_string_forget(&cli_enc_opt_data, MDL);
++	}
++	if (opt_state != NULL) {
++		option_state_dereference(&opt_state, MDL);
++	}
++}
++
++/*
++ * Decline means a client has detected that something else is using an
++ * address we gave it.
++ *
++ * Since we're only dealing with fixed leases for now, there's not
++ * much we can do, other that log the occurrence.
++ * 
++ * When we start issuing addresses from pools, then we will have to
++ * record our declined addresses and issue another. In general with
++ * IPv6 there is no worry about DoS by clients exhausting space, but
++ * we still need to be aware of this possibility.
++ */
++
++/* TODO: reject unicast messages, unless we set unicast option */
++/* TODO: IA_TA */
++static void
++dhcpv6_decline(struct data_string *reply, struct packet *packet) {
++	struct data_string client_id;
++	struct data_string server_id;
++
++	/* 
++	 * Validate our input.
++	 */
++	if (!valid_client_resp(packet, &client_id, &server_id)) {
++		return;
++	}
++
++	/*
++	 * Undefined for IA_PD.
++	 */
++	delete_option(&dhcpv6_universe, packet->options, D6O_IA_PD);
++
++	/*
++	 * And operate on each IA_NA in this packet.
++	 */
++	iterate_over_ia_na(reply, packet, &client_id, &server_id, "Decline", 
++			   ia_na_match_decline, ia_na_nomatch_decline);
++
++	data_string_forget(&server_id, MDL);
++	data_string_forget(&client_id, MDL);
++}
++
++static void
++ia_na_match_release(const struct data_string *client_id,
++		    const struct data_string *iaaddr,
++		    struct iasubopt *lease)
++{
++	char tmp_addr[INET6_ADDRSTRLEN];
++
++	log_info("Client %s releases address %s",
++		 print_hex_1(client_id->len, client_id->data, 60),
++		 inet_ntop(AF_INET6, iaaddr->data, tmp_addr, sizeof(tmp_addr)));
++	if (lease != NULL) {
++		release_lease6(lease->ipv6_pool, lease);
++		lease->ia->cltt = cur_time;
++		write_ia(lease->ia);
++	}
++}
++
++static void
++ia_na_nomatch_release(const struct data_string *client_id,
++		      const struct data_string *iaaddr,
++		      u_int32_t *ia_na_id,
++		      struct packet *packet,
++		      char *reply_data,
++		      int *reply_ofs,
++		      int reply_len)
++{
++	char tmp_addr[INET6_ADDRSTRLEN];
++	struct option_state *host_opt_state;
++	int len;
++
++	log_info("Client %s releases address %s, which is not leased to it.",
++		 print_hex_1(client_id->len, client_id->data, 60),
++		 inet_ntop(AF_INET6, iaaddr->data, tmp_addr, sizeof(tmp_addr)));
++
++	/*
++	 * Create state for this IA_NA.
++	 */
++	host_opt_state = NULL;
++	if (!option_state_allocate(&host_opt_state, MDL)) {
++		log_error("ia_na_nomatch_release: out of memory "
++			  "allocating option_state.");
++		goto exit;
++	}
++
++	if (!set_status_code(STATUS_NoBinding, 
++			     "Release for non-leased address.",
++			     host_opt_state)) {
++		goto exit;
++	}
++
++	/*
++	 * Insure we have enough space
++	 */
++	if (reply_len < (*reply_ofs + 16)) {
++		log_error("ia_na_nomatch_release: "
++			  "out of space for reply packet.");
++		goto exit;
++	}
++
++	/*
++	 * Put our status code into the reply packet.
++	 */
++	len = store_options6(reply_data+(*reply_ofs)+16,
++			     reply_len-(*reply_ofs)-16,
++			     host_opt_state, packet,
++			     required_opts_STATUS_CODE, NULL);
++
++	/*
++	 * Store the non-encapsulated option data for this 
++	 * IA_NA into our reply packet. Defined in RFC 3315, 
++	 * section 22.4.  
++	 */
++	/* option number */
++	putUShort((unsigned char *)reply_data+(*reply_ofs), D6O_IA_NA);
++	/* option length */
++	putUShort((unsigned char *)reply_data+(*reply_ofs)+2, len + 12);
++	/* IA_NA, copied from the client */
++	memcpy(reply_data+(*reply_ofs)+4, ia_na_id, 4);
++	/* t1 and t2, odd that we need them, but here it is */
++	putULong((unsigned char *)reply_data+(*reply_ofs)+8, 0);
++	putULong((unsigned char *)reply_data+(*reply_ofs)+12, 0);
++
++	/*
++	 * Get ready for next IA_NA.
++	 */
++	*reply_ofs += (len + 16);
++
++exit:
++	option_state_dereference(&host_opt_state, MDL);
++}
++
++static void
++ia_pd_match_release(const struct data_string *client_id,
++		    const struct data_string *iapref,
++		    struct iasubopt *prefix)
++{
++	char tmp_addr[INET6_ADDRSTRLEN];
++
++	log_info("Client %s releases prefix %s/%u",
++		 print_hex_1(client_id->len, client_id->data, 60),
++		 inet_ntop(AF_INET6, iapref->data + 9,
++			   tmp_addr, sizeof(tmp_addr)),
++		 (unsigned) getUChar(iapref->data + 8));
++	if (prefix != NULL) {
++		release_lease6(prefix->ipv6_pool, prefix);
++		prefix->ia->cltt = cur_time;
++		write_ia(prefix->ia);
++	}
++}
++
++static void
++ia_pd_nomatch_release(const struct data_string *client_id,
++		      const struct data_string *iapref,
++		      u_int32_t *ia_pd_id,
++		      struct packet *packet,
++		      char *reply_data,
++		      int *reply_ofs,
++		      int reply_len)
++{
++	char tmp_addr[INET6_ADDRSTRLEN];
++	struct option_state *host_opt_state;
++	int len;
++
++	log_info("Client %s releases prefix %s/%u, which is not leased to it.",
++		 print_hex_1(client_id->len, client_id->data, 60),
++		 inet_ntop(AF_INET6, iapref->data + 9,
++			   tmp_addr, sizeof(tmp_addr)),
++		 (unsigned) getUChar(iapref->data + 8));
++
++	/*
++	 * Create state for this IA_PD.
++	 */
++	host_opt_state = NULL;
++	if (!option_state_allocate(&host_opt_state, MDL)) {
++		log_error("ia_pd_nomatch_release: out of memory "
++			  "allocating option_state.");
++		goto exit;
++	}
++
++	if (!set_status_code(STATUS_NoBinding, 
++			     "Release for non-leased prefix.",
++			     host_opt_state)) {
++		goto exit;
++	}
++
++	/*
++	 * Insure we have enough space
++	 */
++	if (reply_len < (*reply_ofs + 16)) {
++		log_error("ia_pd_nomatch_release: "
++			  "out of space for reply packet.");
++		goto exit;
++	}
++
++	/*
++	 * Put our status code into the reply packet.
++	 */
++	len = store_options6(reply_data+(*reply_ofs)+16,
++			     reply_len-(*reply_ofs)-16,
++			     host_opt_state, packet,
++			     required_opts_STATUS_CODE, NULL);
++
++	/*
++	 * Store the non-encapsulated option data for this 
++	 * IA_PD into our reply packet. Defined in RFC 3315, 
++	 * section 22.4.  
++	 */
++	/* option number */
++	putUShort((unsigned char *)reply_data+(*reply_ofs), D6O_IA_PD);
++	/* option length */
++	putUShort((unsigned char *)reply_data+(*reply_ofs)+2, len + 12);
++	/* IA_PD, copied from the client */
++	memcpy(reply_data+(*reply_ofs)+4, ia_pd_id, 4);
++	/* t1 and t2, odd that we need them, but here it is */
++	putULong((unsigned char *)reply_data+(*reply_ofs)+8, 0);
++	putULong((unsigned char *)reply_data+(*reply_ofs)+12, 0);
++
++	/*
++	 * Get ready for next IA_PD.
++	 */
++	*reply_ofs += (len + 16);
++
++exit:
++	option_state_dereference(&host_opt_state, MDL);
++}
++
++static void
++iterate_over_ia_pd(struct data_string *reply_ret, 
++		   struct packet *packet,
++		   const struct data_string *client_id,
++		   const struct data_string *server_id,
++		   const char *packet_type,
++		   void (*ia_pd_match)(),
++		   void (*ia_pd_nomatch)())
++{
++	struct data_string reply_new;
++	int reply_len;
++	struct option_state *opt_state;
++	struct host_decl *packet_host;
++	struct option_cache *ia;
++	struct option_cache *oc;
++	/* cli_enc_... variables come from the IA_PD options */
++	struct data_string cli_enc_opt_data;
++	struct option_state *cli_enc_opt_state;
++	struct host_decl *host;
++	struct option_state *host_opt_state;
++	struct data_string iaprefix;
++	int iaprefix_is_found;
++	char reply_data[65536];
++	int reply_ofs;
++	struct iasubopt *prefix;
++	struct ia_xx *existing_ia_pd;
++	int i;
++	struct data_string key;
++	u_int32_t iaid;
++
++	/*
++	 * Initialize to empty values, in case we have to exit early.
++	 */
++	memset(&reply_new, 0, sizeof(reply_new));
++	opt_state = NULL;
++	memset(&cli_enc_opt_data, 0, sizeof(cli_enc_opt_data));
++	cli_enc_opt_state = NULL;
++	memset(&iaprefix, 0, sizeof(iaprefix));
++	host_opt_state = NULL;
++	prefix = NULL;
++
++	/*
++	 * Compute the available length for the reply.
++	 */
++	reply_len = sizeof(reply_data) - reply_ret->len;
++	reply_ofs = 0;
++
++	/* 
++	 * Find the host record that matches from the packet, if any.
++	 */
++	packet_host = NULL;
++	if (!find_hosts_by_uid(&packet_host, 
++			       client_id->data, client_id->len, MDL)) {
++		packet_host = NULL;
++		/* 
++		 * Note: In general, we don't expect a client to provide
++		 *       enough information to match by option for these
++		 *       types of messages, but if we don't have a UID
++		 *       match we can check anyway.
++		 */
++		if (!find_hosts_by_option(&packet_host, 
++					  packet, packet->options, MDL)) {
++			packet_host = NULL;
++		}
++	}
++
++	/*
++	 * Build our option state for reply.
++	 */
++	opt_state = NULL;
++	if (!option_state_allocate(&opt_state, MDL)) {
++		log_error("iterate_over_ia_pd: no memory for option_state.");
++		goto exit;
++	}
++	execute_statements_in_scope(NULL, packet, NULL, NULL, 
++				    packet->options, opt_state, 
++				    &global_scope, root_group, NULL);
++
++	/*
++	 * Loop through the IA_PD reported by the client, and deal with
++	 * prefixes reported as already in use.
++	 */
++	for (ia = lookup_option(&dhcpv6_universe, packet->options, D6O_IA_PD);
++	     ia != NULL; ia = ia->next) {
++	    iaprefix_is_found = 0;
++
++	    if (!get_encapsulated_IA_state(&cli_enc_opt_state,
++					   &cli_enc_opt_data,
++					   packet, ia, IA_PD_OFFSET)) {
++		goto exit;
++	    }
++
++	    iaid = getULong(cli_enc_opt_data.data);
++
++	    oc = lookup_option(&dhcpv6_universe, cli_enc_opt_state, 
++			       D6O_IAPREFIX);
++	    if (oc == NULL) {
++		/* no prefix given for this IA_PD, ignore */
++		option_state_dereference(&cli_enc_opt_state, MDL);
++		data_string_forget(&cli_enc_opt_data, MDL);
++		continue;
++	    }
++
++	    for (; oc != NULL; oc = oc->next) {
++		memset(&iaprefix, 0, sizeof(iaprefix));
++		if (!evaluate_option_cache(&iaprefix, packet, NULL, NULL, 
++					   packet->options, NULL,
++					   &global_scope, oc, MDL)) {
++			log_error("iterate_over_ia_pd: "
++				  "error evaluating IAPREFIX.");
++			goto exit;
++		}
++
++		/* 
++		 * Now we need to figure out which host record matches
++		 * this IA_PD and IAPREFIX.
++		 *
++		 * XXX: We don't currently track IA_PD separately, but
++		 *      we will need to do this!
++		 */
++		host = NULL;
++		if (!find_hosts_by_option(&host, packet, 
++					  cli_enc_opt_state, MDL)) { 
++			if (packet_host != NULL) {
++				host = packet_host;
++			} else {
++				host = NULL;
++			}
++		}
++		while (host != NULL) {
++			if (host->fixed_prefix != NULL) {
++				struct iaddrcidrnetlist *l;
++				int plen = (int) getUChar(iaprefix.data + 8);
++
++				for (l = host->fixed_prefix; l != NULL;
++				     l = l->next) {
++					if (plen != l->cidrnet.bits)
++						continue;
++					if (memcmp(iaprefix.data + 9,
++						   l->cidrnet.lo_addr.iabuf,
++						   16) == 0)
++						break;
++				}
++				if ((l != NULL) && (iaprefix.len >= 17))
++					break;
++			}
++			host = host->n_ipaddr;
++		}
++
++		if ((host == NULL) && (iaprefix.len >= IAPREFIX_OFFSET)) {
++			/*
++			 * Find existing IA_PD.
++			 */
++			if (ia_make_key(&key, iaid, 
++					(char *)client_id->data,
++					client_id->len, 
++					MDL) != ISC_R_SUCCESS) {
++				log_fatal("iterate_over_ia_pd: no memory for "
++					  "key.");
++			}
++
++			existing_ia_pd = NULL;
++			if (ia_hash_lookup(&existing_ia_pd, ia_pd_active, 
++					   (unsigned char *)key.data, 
++					   key.len, MDL)) {
++				/* 
++				 * Make sure this prefix is in the IA_PD.
++				 */
++				for (i = 0;
++				     i < existing_ia_pd->num_iasubopt;
++				     i++) {
++					struct iasubopt *tmp;
++					u_int8_t plen;
++
++					plen = getUChar(iaprefix.data + 8);
++					tmp = existing_ia_pd->iasubopt[i];
++					if ((tmp->plen == plen) &&
++					    (memcmp(&tmp->addr,
++						    iaprefix.data + 9,
++						    16) == 0)) {
++						iasubopt_reference(&prefix,
++								   tmp, MDL);
++						break;
++					}
++				}
++			}
++
++			data_string_forget(&key, MDL);
++		}
++
++		if ((host != NULL) || (prefix != NULL)) {
++			ia_pd_match(client_id, &iaprefix, prefix);
++		} else {
++			ia_pd_nomatch(client_id, &iaprefix, 
++				      (u_int32_t *)cli_enc_opt_data.data, 
++				      packet, reply_data, &reply_ofs, 
++				      reply_len - reply_ofs);
++		}
++
++		if (prefix != NULL) {
++			iasubopt_dereference(&prefix, MDL);
++		}
++
++		data_string_forget(&iaprefix, MDL);
++	    }
++
++	    option_state_dereference(&cli_enc_opt_state, MDL);
++	    data_string_forget(&cli_enc_opt_data, MDL);
++	}
++
++	/* 
++	 * Return our reply to the caller.
++	 * The IA_NA routine has already filled at least the header.
++	 */
++	reply_new.len = reply_ret->len + reply_ofs;
++	if (!buffer_allocate(&reply_new.buffer, reply_new.len, MDL)) {
++		log_fatal("No memory to store reply.");
++	}
++	reply_new.data = reply_new.buffer->data;
++	memcpy(reply_new.buffer->data,
++	       reply_ret->buffer->data, reply_ret->len);
++	memcpy(reply_new.buffer->data + reply_ret->len,
++	       reply_data, reply_ofs);
++	data_string_forget(reply_ret, MDL);
++	data_string_copy(reply_ret, &reply_new, MDL);
++	data_string_forget(&reply_new, MDL);
++
++exit:
++	if (prefix != NULL) {
++		iasubopt_dereference(&prefix, MDL);
++	}
++	if (host_opt_state != NULL) {
++		option_state_dereference(&host_opt_state, MDL);
++	}
++	if (iaprefix.buffer != NULL) {
++		data_string_forget(&iaprefix, MDL);
++	}
++	if (cli_enc_opt_state != NULL) {
++		option_state_dereference(&cli_enc_opt_state, MDL);
++	}
++	if (cli_enc_opt_data.buffer != NULL) {
++		data_string_forget(&cli_enc_opt_data, MDL);
++	}
++	if (opt_state != NULL) {
++		option_state_dereference(&opt_state, MDL);
++	}
++}
++
++/*
++ * Release means a client is done with the leases.
++ */
++
++/* TODO: reject unicast messages, unless we set unicast option */
++static void
++dhcpv6_release(struct data_string *reply, struct packet *packet) {
++	struct data_string client_id;
++	struct data_string server_id;
++
++	/* 
++	 * Validate our input.
++	 */
++	if (!valid_client_resp(packet, &client_id, &server_id)) {
++		return;
++	}
++
++	/*
++	 * And operate on each IA_NA in this packet.
++	 */
++	iterate_over_ia_na(reply, packet, &client_id, &server_id, "Release", 
++			   ia_na_match_release, ia_na_nomatch_release);
++
++	/*
++	 * And operate on each IA_PD in this packet.
++	 */
++	iterate_over_ia_pd(reply, packet, &client_id, &server_id, "Release",
++			   ia_pd_match_release, ia_pd_nomatch_release);
++
++	data_string_forget(&server_id, MDL);
++	data_string_forget(&client_id, MDL);
++}
++
++/*
++ * Information-Request is used by clients who have obtained an address
++ * from other means, but want configuration information from the server.
++ */
++
++static void
++dhcpv6_information_request(struct data_string *reply, struct packet *packet) {
++	struct data_string client_id;
++	struct data_string server_id;
++
++	/*
++	 * Validate our input.
++	 */
++	if (!valid_client_info_req(packet, &server_id)) {
++		return;
++	}
++
++	/*
++	 * Get our client ID, if there is one.
++	 */
++	memset(&client_id, 0, sizeof(client_id));
++	if (get_client_id(packet, &client_id) != ISC_R_SUCCESS) {
++		data_string_forget(&client_id, MDL);
++	}
++
++	/*
++	 * Use the lease_to_client() function. This will work fine, 
++	 * because the valid_client_info_req() insures that we 
++	 * don't have any IA that would cause us to allocate
++	 * resources to the client.
++	 */
++	lease_to_client(reply, packet, &client_id,
++			server_id.data != NULL ? &server_id : NULL);
++
++	/*
++	 * Cleanup.
++	 */
++	if (client_id.data != NULL) {
++		data_string_forget(&client_id, MDL);
++	}
++	data_string_forget(&server_id, MDL);
++}
++
++/* 
++ * The Relay-forw message is sent by relays. It typically contains a
++ * single option, which encapsulates an entire packet.
++ *
++ * We need to build an encapsulated reply.
++ */
++
++/* XXX: this is very, very similar to do_packet6(), and should probably
++	be combined in a clever way */
++static void
++dhcpv6_relay_forw(struct data_string *reply_ret, struct packet *packet) {
++	struct option_cache *oc;
++	struct data_string enc_opt_data;
++	struct packet *enc_packet;
++	unsigned char msg_type;
++	const struct dhcpv6_packet *msg;
++	const struct dhcpv6_relay_packet *relay;
++	struct data_string enc_reply;
++	char link_addr[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")];
++	char peer_addr[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")];
++	struct data_string a_opt, packet_ero;
++	struct option_state *opt_state;
++	static char reply_data[65536];
++	struct dhcpv6_relay_packet *reply;
++	int reply_ofs;
++
++	/* 
++	 * Initialize variables for early exit.
++	 */
++	opt_state = NULL;
++	memset(&a_opt, 0, sizeof(a_opt));
++	memset(&packet_ero, 0, sizeof(packet_ero));
++	memset(&enc_reply, 0, sizeof(enc_reply));
++	memset(&enc_opt_data, 0, sizeof(enc_opt_data));
++	enc_packet = NULL;
++
++	/*
++	 * Get our encapsulated relay message.
++	 */
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_RELAY_MSG);
++	if (oc == NULL) {
++		inet_ntop(AF_INET6, &packet->dhcpv6_link_address,
++			  link_addr, sizeof(link_addr));
++		inet_ntop(AF_INET6, &packet->dhcpv6_peer_address,
++			  peer_addr, sizeof(peer_addr));
++		log_info("Relay-forward from %s with link address=%s and "
++			 "peer address=%s missing Relay Message option.",
++			  piaddr(packet->client_addr), link_addr, peer_addr);
++		goto exit;
++	}
++
++	if (!evaluate_option_cache(&enc_opt_data, NULL, NULL, NULL, 
++				   NULL, NULL, &global_scope, oc, MDL)) {
++		log_error("dhcpv6_forw_relay: error evaluating "
++			  "relayed message.");
++		goto exit;
++	}
++
++	if (!packet6_len_okay((char *)enc_opt_data.data, enc_opt_data.len)) {
++		log_error("dhcpv6_forw_relay: encapsulated packet too short.");
++		goto exit;
++	}
++
++	/*
++	 * Build a packet structure from this encapsulated packet.
++	 */
++	enc_packet = NULL;
++	if (!packet_allocate(&enc_packet, MDL)) {
++		log_error("dhcpv6_forw_relay: "
++			  "no memory for encapsulated packet.");
++		goto exit;
++	}
++
++	if (!option_state_allocate(&enc_packet->options, MDL)) {
++		log_error("dhcpv6_forw_relay: "
++			  "no memory for encapsulated packet's options.");
++		goto exit;
++	}
++
++	enc_packet->client_port = packet->client_port;
++	enc_packet->client_addr = packet->client_addr;
++	enc_packet->dhcpv6_container_packet = packet;
++
++	msg_type = enc_opt_data.data[0];
++	if ((msg_type == DHCPV6_RELAY_FORW) ||
++	    (msg_type == DHCPV6_RELAY_REPL)) {
++		relay = (struct dhcpv6_relay_packet *)enc_opt_data.data;
++		enc_packet->dhcpv6_msg_type = relay->msg_type;
++
++		/* relay-specific data */
++		enc_packet->dhcpv6_hop_count = relay->hop_count;
++		memcpy(&enc_packet->dhcpv6_link_address,
++		       relay->link_address, sizeof(relay->link_address));
++		memcpy(&enc_packet->dhcpv6_peer_address,
++		       relay->peer_address, sizeof(relay->peer_address));
++
++		if (!parse_option_buffer(enc_packet->options,
++					 relay->options, 
++					 enc_opt_data.len-sizeof(*relay),
++					 &dhcpv6_universe)) {
++			/* no logging here, as parse_option_buffer() logs all
++			   cases where it fails */
++			goto exit;
++		}
++	} else {
++		msg = (struct dhcpv6_packet *)enc_opt_data.data;
++		enc_packet->dhcpv6_msg_type = msg->msg_type;
++
++		/* message-specific data */
++		memcpy(enc_packet->dhcpv6_transaction_id,
++		       msg->transaction_id,
++		       sizeof(enc_packet->dhcpv6_transaction_id));
++
++		if (!parse_option_buffer(enc_packet->options,
++					 msg->options, 
++					 enc_opt_data.len-sizeof(*msg),
++					 &dhcpv6_universe)) {
++			/* no logging here, as parse_option_buffer() logs all
++			   cases where it fails */
++			goto exit;
++		}
++	}
++
++	/*
++	 * This is recursive. It is possible to exceed maximum packet size.
++	 * XXX: This will cause the packet send to fail.
++	 */
++	build_dhcpv6_reply(&enc_reply, enc_packet);
++
++	/*
++	 * If we got no encapsulated data, then it is discarded, and
++	 * our reply-forw is also discarded.
++	 */
++	if (enc_reply.data == NULL) {
++		goto exit;
++	}
++
++	/*
++	 * Now we can use the reply_data buffer.
++	 * Packet header stuff all comes from the forward message.
++	 */
++	reply = (struct dhcpv6_relay_packet *)reply_data;
++	reply->msg_type = DHCPV6_RELAY_REPL;
++	reply->hop_count = packet->dhcpv6_hop_count;
++	memcpy(reply->link_address, &packet->dhcpv6_link_address,
++	       sizeof(reply->link_address));
++	memcpy(reply->peer_address, &packet->dhcpv6_peer_address,
++	       sizeof(reply->peer_address));
++	reply_ofs = (int)((char *)reply->options - (char *)reply);
++
++	/*
++	 * Get the reply option state.
++	 */
++	opt_state = NULL;
++	if (!option_state_allocate(&opt_state, MDL)) {
++		log_error("dhcpv6_relay_forw: no memory for option state.");
++		goto exit;
++	}
++
++	/*
++	 * Append the interface-id if present.
++	 */
++	oc = lookup_option(&dhcpv6_universe, packet->options,
++			   D6O_INTERFACE_ID);
++	if (oc != NULL) {
++		if (!evaluate_option_cache(&a_opt, packet,
++					   NULL, NULL, 
++					   packet->options, NULL,
++					   &global_scope, oc, MDL)) {
++			log_error("dhcpv6_relay_forw: error evaluating "
++				  "Interface ID.");
++			goto exit;
++		}
++		if (!save_option_buffer(&dhcpv6_universe, opt_state, NULL,
++					(unsigned char *)a_opt.data,
++					a_opt.len,
++					D6O_INTERFACE_ID, 0)) {
++			log_error("dhcpv6_relay_forw: error saving "
++				  "Interface ID.");
++			goto exit;
++		}
++		data_string_forget(&a_opt, MDL);
++	}
++
++	/* 
++	 * Append our encapsulated stuff for caller.
++	 */
++	if (!save_option_buffer(&dhcpv6_universe, opt_state, NULL,
++				(unsigned char *)enc_reply.data,
++				enc_reply.len,
++				D6O_RELAY_MSG, 0)) {
++		log_error("dhcpv6_relay_forw: error saving Relay MSG.");
++		goto exit;
++	}
++
++	/*
++	 * Get the ERO if any.
++	 */
++	oc = lookup_option(&dhcpv6_universe, packet->options, D6O_ERO);
++	if (oc != NULL) {
++		unsigned req;
++		int i;
++
++		if (!evaluate_option_cache(&packet_ero, packet,
++					   NULL, NULL,
++					   packet->options, NULL,
++					   &global_scope, oc, MDL) ||
++			(packet_ero.len & 1)) {
++			log_error("dhcpv6_relay_forw: error evaluating ERO.");
++			goto exit;
++		}
++
++		/* Decode and apply the ERO. */
++		for (i = 0; i < packet_ero.len; i += 2) {
++			req = getUShort(packet_ero.data + i);
++			/* Already in the reply? */
++			oc = lookup_option(&dhcpv6_universe, opt_state, req);
++			if (oc != NULL)
++				continue;
++			/* Get it from the packet if present. */
++			oc = lookup_option(&dhcpv6_universe,
++					   packet->options,
++					   req);
++			if (oc == NULL)
++				continue;
++			if (!evaluate_option_cache(&a_opt, packet,
++						   NULL, NULL,
++						   packet->options, NULL,
++						   &global_scope, oc, MDL)) {
++				log_error("dhcpv6_relay_forw: error "
++					  "evaluating option %u.", req);
++				goto exit;
++			}
++			if (!save_option_buffer(&dhcpv6_universe,
++						opt_state,
++						NULL,
++						(unsigned char *)a_opt.data,
++						a_opt.len,
++						req,
++						0)) {
++				log_error("dhcpv6_relay_forw: error saving "
++					  "option %u.", req);
++				goto exit;
++			}
++			data_string_forget(&a_opt, MDL);
++		}
++	}
++
++	reply_ofs += store_options6(reply_data + reply_ofs,
++				    sizeof(reply_data) - reply_ofs,
++				    opt_state, packet,
++				    required_opts_agent, &packet_ero);
++
++	/*
++	 * Return our reply to the caller.
++	 */
++	reply_ret->len = reply_ofs;
++	reply_ret->buffer = NULL;
++	if (!buffer_allocate(&reply_ret->buffer, reply_ret->len, MDL)) {
++		log_fatal("No memory to store reply.");
++	}
++	reply_ret->data = reply_ret->buffer->data;
++	memcpy(reply_ret->buffer->data, reply_data, reply_ofs);
++
++exit:
++	if (opt_state != NULL)
++		option_state_dereference(&opt_state, MDL);
++	if (a_opt.data != NULL) {
++		data_string_forget(&a_opt, MDL);
++	}
++	if (packet_ero.data != NULL) {
++		data_string_forget(&packet_ero, MDL);
++	}
++	if (enc_reply.data != NULL) {
++		data_string_forget(&enc_reply, MDL);
++	}
++	if (enc_opt_data.data != NULL) {
++		data_string_forget(&enc_opt_data, MDL);
++	}
++	if (enc_packet != NULL) {
++		packet_dereference(&enc_packet, MDL);
++	}
++}
++
++static void
++dhcpv6_discard(struct packet *packet) {
++	/* INSIST(packet->msg_type > 0); */
++	/* INSIST(packet->msg_type < dhcpv6_type_name_max); */
++
++	log_debug("Discarding %s from %s; message type not handled by server", 
++		  dhcpv6_type_names[packet->dhcpv6_msg_type],
++		  piaddr(packet->client_addr));
++}
++
++static void 
++build_dhcpv6_reply(struct data_string *reply, struct packet *packet) {
++	memset(reply, 0, sizeof(*reply));
++	switch (packet->dhcpv6_msg_type) {
++		case DHCPV6_SOLICIT:
++			dhcpv6_solicit(reply, packet);
++			break;
++		case DHCPV6_ADVERTISE:
++			dhcpv6_discard(packet);
++			break;
++		case DHCPV6_REQUEST:
++			dhcpv6_request(reply, packet);
++			break;
++		case DHCPV6_CONFIRM:
++			dhcpv6_confirm(reply, packet);
++			break;
++		case DHCPV6_RENEW:
++			dhcpv6_renew(reply, packet);
++			break;
++		case DHCPV6_REBIND:
++			dhcpv6_rebind(reply, packet);
++			break;
++		case DHCPV6_REPLY:
++			dhcpv6_discard(packet);
++			break;
++		case DHCPV6_RELEASE:
++			dhcpv6_release(reply, packet);
++			break;
++		case DHCPV6_DECLINE:
++			dhcpv6_decline(reply, packet);
++			break;
++		case DHCPV6_RECONFIGURE:
++			dhcpv6_discard(packet);
++			break;
++		case DHCPV6_INFORMATION_REQUEST:
++			dhcpv6_information_request(reply, packet);
++			break;
++		case DHCPV6_RELAY_FORW:
++			dhcpv6_relay_forw(reply, packet);
++			break;
++		case DHCPV6_RELAY_REPL:
++			dhcpv6_discard(packet);
++			break;
++		case DHCPV6_LEASEQUERY:
++			dhcpv6_leasequery(reply, packet);
++			break;
++		case DHCPV6_LEASEQUERY_REPLY:
++			dhcpv6_discard(packet);
++			break;
++		default:
++			/* XXX: would be nice if we had "notice" level, 
++				as syslog, for this */
++			log_info("Discarding unknown DHCPv6 message type %d "
++				 "from %s", packet->dhcpv6_msg_type, 
++				 piaddr(packet->client_addr));
++	}
++}
++
++static void
++log_packet_in(const struct packet *packet) {
++	struct data_string s;
++	u_int32_t tid;
++	char tmp_addr[INET6_ADDRSTRLEN];
++	const void *addr;
++
++	memset(&s, 0, sizeof(s));
++
++	if (packet->dhcpv6_msg_type < dhcpv6_type_name_max) {
++		data_string_sprintfa(&s, "%s message from %s port %d",
++				     dhcpv6_type_names[packet->dhcpv6_msg_type],
++				     piaddr(packet->client_addr),
++				     ntohs(packet->client_port));
++	} else {
++		data_string_sprintfa(&s, 
++				     "Unknown message type %d from %s port %d",
++				     packet->dhcpv6_msg_type,
++				     piaddr(packet->client_addr),
++				     ntohs(packet->client_port));
++	}
++	if ((packet->dhcpv6_msg_type == DHCPV6_RELAY_FORW) || 
++	    (packet->dhcpv6_msg_type == DHCPV6_RELAY_REPL)) {
++	    	addr = &packet->dhcpv6_link_address;
++	    	data_string_sprintfa(&s, ", link address %s", 
++				     inet_ntop(AF_INET6, addr, 
++					       tmp_addr, sizeof(tmp_addr)));
++	    	addr = &packet->dhcpv6_peer_address;
++	    	data_string_sprintfa(&s, ", peer address %s", 
++				     inet_ntop(AF_INET6, addr, 
++					       tmp_addr, sizeof(tmp_addr)));
++	} else {
++		tid = 0;
++		memcpy(((char *)&tid)+1, packet->dhcpv6_transaction_id, 3);
++		data_string_sprintfa(&s, ", transaction ID 0x%06X", tid);
++
++/*
++		oc = lookup_option(&dhcpv6_universe, packet->options, 
++				   D6O_CLIENTID);
++		if (oc != NULL) {
++			memset(&tmp_ds, 0, sizeof(tmp_ds_));
++			if (!evaluate_option_cache(&tmp_ds, packet, NULL, NULL, 
++						   packet->options, NULL,
++						   &global_scope, oc, MDL)) {
++				log_error("Error evaluating Client Identifier");
++			} else {
++				data_strint_sprintf(&s, ", client ID %s",
++
++				data_string_forget(&tmp_ds, MDL);
++			}
++		}
++*/
++
++	}
++	log_info("%s", s.data);
++
++	data_string_forget(&s, MDL);
++}
++
++void 
++dhcpv6(struct packet *packet) {
++	struct data_string reply;
++	struct sockaddr_in6 to_addr;
++	int send_ret;
++
++	/* 
++	 * Log a message that we received this packet.
++	 */
++	log_packet_in(packet); 
++
++	/*
++	 * Build our reply packet.
++	 */
++	build_dhcpv6_reply(&reply, packet);
++
++	if (reply.data != NULL) {
++		/* 
++		 * Send our reply, if we have one.
++		 */
++		memset(&to_addr, 0, sizeof(to_addr));
++		to_addr.sin6_family = AF_INET6;
++		if ((packet->dhcpv6_msg_type == DHCPV6_RELAY_FORW) || 
++		    (packet->dhcpv6_msg_type == DHCPV6_RELAY_REPL)) {
++			to_addr.sin6_port = local_port;
++		} else {
++			to_addr.sin6_port = remote_port;
++		}
++/* For testing, we reply to the sending port, so we don't need a root client */
++		to_addr.sin6_port = packet->client_port;
++		memcpy(&to_addr.sin6_addr, packet->client_addr.iabuf, 
++		       sizeof(to_addr.sin6_addr));
++
++		log_info("Sending %s to %s port %d", 
++			 dhcpv6_type_names[reply.data[0]],
++			 piaddr(packet->client_addr),
++			 ntohs(to_addr.sin6_port));
++
++		send_ret = send_packet6(packet->interface, 
++					reply.data, reply.len, &to_addr);
++		if (send_ret != reply.len) {
++			log_error("dhcpv6: send_packet6() sent %d of %d bytes",
++				  send_ret, reply.len);
++		}
++		data_string_forget(&reply, MDL);
++	}
++}
++
++static void
++seek_shared_host(struct host_decl **hp, struct shared_network *shared) {
++	struct host_decl *nofixed = NULL;
++	struct host_decl *seek, *hold = NULL;
++
++	/*
++	 * Seek forward through fixed addresses for the right link.
++	 *
++	 * Note: how to do this for fixed prefixes???
++	 */
++	host_reference(&hold, *hp, MDL);
++	host_dereference(hp, MDL);
++	seek = hold;
++	while (seek != NULL) {
++		if (seek->fixed_addr == NULL)
++			nofixed = seek;
++		else if (fixed_matches_shared(seek, shared))
++			break;
++
++		seek = seek->n_ipaddr;
++	}
++
++	if ((seek == NULL) && (nofixed != NULL))
++		seek = nofixed;
++
++	if (seek != NULL)
++		host_reference(hp, seek, MDL);
++}
++
++static isc_boolean_t
++fixed_matches_shared(struct host_decl *host, struct shared_network *shared) {
++	struct subnet *subnet;
++	struct data_string addr;
++	isc_boolean_t matched;
++	struct iaddr fixed;
++
++	if (host->fixed_addr == NULL)
++		return ISC_FALSE;
++
++	memset(&addr, 0, sizeof(addr));
++	if (!evaluate_option_cache(&addr, NULL, NULL, NULL, NULL, NULL,
++				   &global_scope, host->fixed_addr, MDL))
++		return ISC_FALSE;
++
++	if (addr.len < 16) {
++		data_string_forget(&addr, MDL);
++		return ISC_FALSE;
++	}
++
++	fixed.len = 16;
++	memcpy(fixed.iabuf, addr.data, 16);
++
++	matched = ISC_FALSE;
++	for (subnet = shared->subnets ; subnet != NULL ;
++	     subnet = subnet->next_sibling) {
++		if (addr_eq(subnet_number(fixed, subnet->netmask),
++			    subnet->net)) {
++			matched = ISC_TRUE;
++			break;
++		}
++	}
++
++	data_string_forget(&addr, MDL);
++	return matched;
++}
++
++#endif /* DHCPv6 */
++

-- 
ISC DHCP packaging for Debian



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