From: Hans Dedecker <dedeckeh@gmail.com>
Date: Mon, 23 Apr 2018 09:56:27 +0000 (+0200)
Subject: dhcpv6-ia: make assignment lookup more strict
X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fodhcpd.git;a=commitdiff_plain;h=200cc8f556c1cdb8daa3b591116755e4a80ac655;ds=inline

dhcpv6-ia: make assignment lookup more strict

Whe doing an assignment lookup do a strict match between the assignment
IAID and the IAID received form the client in case the BOUND or TENTATIVE
assignment flags are set.
This fixes a wrong assignment being returned for a client which uses a
different IAID than the IAID used in a previous DHCPv6 exchange.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
---

diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index 9afde3f..737b328 100644
--- a/src/dhcpv6-ia.c
+++ b/src/dhcpv6-ia.c
@@ -1161,7 +1161,8 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
 			if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
 					(c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
 						&& !memcmp(c->mac, mac, sizeof(mac)))) &&
-					(c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
+					(!(c->flags & (OAF_BOUND|OAF_TENTATIVE)) || c->iaid == ia->iaid) &&
+					(INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
 					((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
 				a = c;
 
@@ -1257,6 +1258,7 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
 			/* Was only a solicitation: mark binding for removal */
 			if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
 				a->flags &= ~OAF_BOUND;
+				a->flags |= OAF_TENTATIVE;
 
 				if (!(a->flags & OAF_STATIC))
 					a->valid_until = now;
@@ -1271,6 +1273,7 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
 					}
 				}
 				a->accept_reconf = accept_reconf;
+				a->flags &= ~OAF_TENTATIVE;
 				a->flags |= OAF_BOUND;
 				apply_lease(iface, a, true);
 			} else if (!assigned && a && a->managed_size == 0) {
diff --git a/src/odhcpd.h b/src/odhcpd.h
index 48ee51e..9a27708 100644
--- a/src/odhcpd.h
+++ b/src/odhcpd.h
@@ -133,8 +133,9 @@ enum odhcpd_mode {
 
 
 enum odhcpd_assignment_flags {
-	OAF_BOUND	= (1 << 0),
-	OAF_STATIC	= (1 << 1),
+	OAF_TENTATIVE	= (1 << 0),
+	OAF_BOUND	= (1 << 1),
+	OAF_STATIC	= (1 << 2),
 };
 
 struct config {