From b5c20853fcbc081ad950ef2083a4f5c31d6ecb54 Mon Sep 17 00:00:00 2001
From: Steven Barth <steven@midlink.org>
Date: Wed, 31 Jul 2013 19:05:55 +0200
Subject: [PATCH] Include IAs in Request to be more compatible with some
 servers

---
 src/dhcpv6.c  | 33 ++++++++++++++++++++++++++++++---
 src/odhcp6c.c | 23 ++++++++++++++++++++++-
 src/odhcp6c.h |  5 +++++
 3 files changed, 57 insertions(+), 4 deletions(-)

diff --git a/src/dhcpv6.c b/src/dhcpv6.c
index 64c0cb4..9742c39 100644
--- a/src/dhcpv6.c
+++ b/src/dhcpv6.c
@@ -559,12 +559,12 @@ static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig,
 
 
 // Collect all advertised servers
-static int dhcpv6_handle_advert(_unused enum dhcpv6_msg orig,
+static int dhcpv6_handle_advert(enum dhcpv6_msg orig,
 		const void *opt, const void *end)
 {
 	uint16_t olen, otype;
 	uint8_t *odata;
-	struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}};
+	struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}, NULL, NULL, 0, 0};
 
 	dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 		if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
@@ -598,10 +598,25 @@ static int dhcpv6_handle_advert(_unused enum dhcpv6_msg orig,
 					cand.preference -= 2000;
 			}
 		}
+
+		if (orig == DHCPV6_MSG_SOLICIT &&
+				(otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
+				olen > sizeof(struct dhcpv6_ia_hdr)) {
+			struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
+			dhcpv6_parse_ia(&ia_hdr[1], odata + olen);
+		}
 	}
 
-	if (cand.duid_len > 0)
+	if (cand.duid_len > 0) {
+		cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
+		cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
 		odhcp6c_add_state(STATE_SERVER_CAND, &cand, sizeof(cand));
+	}
+
+	if (orig == DHCPV6_MSG_SOLICIT) {
+		odhcp6c_clear_state(STATE_IA_NA);
+		odhcp6c_clear_state(STATE_IA_PD);
+	}
 
 	return -1;
 }
@@ -634,8 +649,14 @@ static int dhcpv6_commit_advert(void)
 		odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
 		odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len);
 		accept_reconfig = c->wants_reconfigure;
+		odhcp6c_add_state(STATE_IA_NA, c->ia_na, c->ia_na_len);
+		odhcp6c_add_state(STATE_IA_PD, c->ia_pd, c->ia_pd_len);
 	}
 
+	for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
+		free(cand[i].ia_na);
+		free(cand[i].ia_pd);
+	}
 	odhcp6c_clear_state(STATE_SERVER_CAND);
 
 	if (!c)
@@ -691,6 +712,12 @@ static int dhcpv6_handle_reply(enum dhcpv6_msg orig,
 		t1 = t2 = t3 = UINT32_MAX;
 	}
 
+	if (orig == DHCPV6_MSG_REQUEST) {
+		// Delete NA and PD we have in the state from the Advert
+		odhcp6c_clear_state(STATE_IA_NA);
+		odhcp6c_clear_state(STATE_IA_PD);
+	}
+
 	if (opt) {
 		odhcp6c_clear_state(STATE_DNS);
 		odhcp6c_clear_state(STATE_SEARCH);
diff --git a/src/odhcp6c.c b/src/odhcp6c.c
index df89eb9..f732d9e 100644
--- a/src/odhcp6c.c
+++ b/src/odhcp6c.c
@@ -192,7 +192,7 @@ int main(_unused int argc, char* const argv[])
 
 	while (do_signal != SIGTERM) { // Main logic
 		odhcp6c_clear_state(STATE_SERVER_ID);
-		odhcp6c_clear_state(STATE_SERVER_CAND);
+		odhcp6c_clear_state(STATE_IA_NA);
 		odhcp6c_clear_state(STATE_IA_PD);
 		odhcp6c_clear_state(STATE_SNTP_IP);
 		odhcp6c_clear_state(STATE_SNTP_FQDN);
@@ -201,6 +201,15 @@ int main(_unused int argc, char* const argv[])
 		dhcpv6_set_ia_na_mode(ia_na_mode);
 		bound = false;
 
+		// Server candidates need deep-delete
+		size_t cand_len;
+		struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
+		for (size_t i = 0; i < cand_len / sizeof(*cand); ++i) {
+			free(cand[i].ia_na);
+			free(cand[i].ia_pd);
+		}
+		odhcp6c_clear_state(STATE_SERVER_CAND);
+
 		syslog(LOG_NOTICE, "(re)starting transaction on %s", ifname);
 
 		do_signal = 0;
@@ -405,6 +414,18 @@ size_t odhcp6c_remove_state(enum odhcp6c_state state, size_t offset, size_t len)
 }
 
 
+void* odhcp6c_move_state(enum odhcp6c_state state, size_t *len)
+{
+	*len = state_len[state];
+	void *data = state_data[state];
+
+	state_len[state] = 0;
+	state_data[state] = NULL;
+
+	return data;
+}
+
+
 void* odhcp6c_get_state(enum odhcp6c_state state, size_t *len)
 {
 	*len = state_len[state];
diff --git a/src/odhcp6c.h b/src/odhcp6c.h
index 2e7107c..ac0932f 100644
--- a/src/odhcp6c.h
+++ b/src/odhcp6c.h
@@ -158,6 +158,10 @@ struct dhcpv6_server_cand {
 	int16_t preference;
 	uint8_t duid_len;
 	uint8_t duid[130];
+	void *ia_na;
+	void *ia_pd;
+	size_t ia_na_len;
+	size_t ia_pd_len;
 };
 
 
@@ -236,6 +240,7 @@ void odhcp6c_random(void *buf, size_t len);
 void odhcp6c_clear_state(enum odhcp6c_state state);
 void odhcp6c_add_state(enum odhcp6c_state state, const void *data, size_t len);
 size_t odhcp6c_remove_state(enum odhcp6c_state state, size_t offset, size_t len);
+void* odhcp6c_move_state(enum odhcp6c_state state, size_t *len);
 void* odhcp6c_get_state(enum odhcp6c_state state, size_t *len);
 
 // Entry manipulation
-- 
2.39.5