Always advertise the Router-ID as the transport address.

RFC 5036 - Section 2.5.2 says:
    An LSR MUST advertise the same transport address in all
    Hellos that advertise the same label space...
To satisfy this condition, always advertise the Router-ID as the
transport address by using the "IPv4 Transport Address" TLV in the
generated Hello messages.
From Renato Westphal

4 files changed, 66 insertions, 25 deletions

diff --git a/usr.sbin/ldpd/hello.c b/usr.sbin/ldpd/hello.c
index 137b6e4f9eb..d56905d3de9 100644
--- a/usr.sbin/ldpd/hello.c
+++ b/usr.sbin/ldpd/hello.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hello.c,v 1.14 2013/05/31 14:10:10 claudio Exp $ */
+/*	$OpenBSD: hello.c,v 1.15 2013/06/01 01:34:56 claudio Exp $ */
 
 /*
  * Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
@@ -39,7 +39,8 @@
 int	tlv_decode_hello_prms(char *, u_int16_t, u_int16_t *, u_int16_t *);
 int	tlv_decode_opt_hello_prms(char *, u_int16_t, struct in_addr *,
 	    u_int32_t *);
-int	gen_hello_prms_tlv(struct iface *, struct ibuf *, u_int16_t);
+int	gen_hello_prms_tlv(struct iface *, struct ibuf *);
+int	gen_opt4_hello_prms_tlv(struct iface *, struct ibuf *);
 
 int
 send_hello(struct iface *iface)
@@ -60,7 +61,8 @@ send_hello(struct iface *iface)
 		fatal("send_hello");
 
 	size = LDP_HDR_SIZE + sizeof(struct ldp_msg) +
-	    sizeof(struct hello_prms_tlv);
+	    sizeof(struct hello_prms_tlv) +
+	    sizeof(struct hello_prms_opt4_tlv);
 
 	gen_ldp_hdr(buf, iface, size);
 
@@ -68,9 +70,8 @@ send_hello(struct iface *iface)
 
 	gen_msg_tlv(buf, MSG_TYPE_HELLO, size);
 
-	size -= sizeof(struct ldp_msg);
-
-	gen_hello_prms_tlv(iface, buf, size);
+	gen_hello_prms_tlv(iface, buf);
+	gen_opt4_hello_prms_tlv(iface, buf);
 
 	send_packet(iface, buf->buf, buf->wpos, &dst);
 	ibuf_free(buf);
@@ -148,23 +149,19 @@ recv_hello(struct iface *iface, struct in_addr src, char *buf, u_int16_t len)
 
 	nbr_fsm(nbr, NBR_EVT_HELLO_RCVD);
 
-	if (ntohl(nbr->addr.s_addr) < ntohl(nbr->iface->addr.s_addr) &&
-	    nbr->state == NBR_STA_PRESENT && !nbr_pending_connect(nbr) &&
-	    !nbr_pending_idtimer(nbr))
+	if (nbr->state == NBR_STA_PRESENT && nbr_session_active_role(nbr) &&
+	    !nbr_pending_connect(nbr) && !nbr_pending_idtimer(nbr))
 		nbr_establish_connection(nbr);
 }
 
 int
-gen_hello_prms_tlv(struct iface *iface, struct ibuf *buf, u_int16_t size)
+gen_hello_prms_tlv(struct iface *iface, struct ibuf *buf)
 {
 	struct hello_prms_tlv	parms;
 
-	/* We want just the size of the value */
-	size -= TLV_HDR_LEN;
-
 	bzero(&parms, sizeof(parms));
 	parms.type = htons(TLV_TYPE_COMMONHELLO);
-	parms.length = htons(size);
+	parms.length = htons(sizeof(parms.holdtime) + sizeof(parms.flags));
 	/* XXX */
 	parms.holdtime = htons(iface->holdtime);
 	parms.flags = 0;
@@ -173,6 +170,19 @@ gen_hello_prms_tlv(struct iface *iface, struct ibuf *buf, u_int16_t size)
 }
 
 int
+gen_opt4_hello_prms_tlv(struct iface *iface, struct ibuf *buf)
+{
+	struct hello_prms_opt4_tlv	parms;
+
+	bzero(&parms, sizeof(parms));
+	parms.type = htons(TLV_TYPE_IPV4TRANSADDR);
+	parms.length = htons(4);
+	parms.value = ldpe_router_id();
+
+	return (ibuf_add(buf, &parms, sizeof(parms)));
+}
+
+int
 tlv_decode_hello_prms(char *buf, u_int16_t len, u_int16_t *holdtime,
     u_int16_t *flags)
 {
diff --git a/usr.sbin/ldpd/ldp.h b/usr.sbin/ldpd/ldp.h
index 6558bbedbd3..b810d19a3dd 100644
--- a/usr.sbin/ldpd/ldp.h
+++ b/usr.sbin/ldpd/ldp.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ldp.h,v 1.10 2013/05/30 16:14:50 claudio Exp $ */
+/*	$OpenBSD: ldp.h,v 1.11 2013/06/01 01:34:57 claudio Exp $ */
 
 /*
  * Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
@@ -126,6 +126,12 @@ struct hello_prms_tlv {
 	u_int16_t	flags;
 };
 
+struct hello_prms_opt4_tlv {
+	u_int16_t	type;
+	u_int16_t	length;
+	u_int32_t	value;
+};
+
 #define HELLO_PRMS_SIZE		8
 
 #define	S_SUCCESS	0x00000000
diff --git a/usr.sbin/ldpd/ldpe.h b/usr.sbin/ldpd/ldpe.h
index 5051d5c30c7..0cd8367daaf 100644
--- a/usr.sbin/ldpd/ldpe.h
+++ b/usr.sbin/ldpd/ldpe.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ldpe.h,v 1.17 2013/05/31 14:10:10 claudio Exp $ */
+/*	$OpenBSD: ldpe.h,v 1.18 2013/06/01 01:34:57 claudio Exp $ */
 
 /*
  * Copyright (c) 2004, 2005, 2008 Esben Norby <norby@openbsd.org>
@@ -159,6 +159,7 @@ struct nbr	*nbr_find_ldpid(u_int32_t, u_int16_t);
 struct nbr	*nbr_find_peerid(u_int32_t);
 
 int	 nbr_fsm(struct nbr *, enum nbr_event);
+int	 nbr_session_active_role(struct nbr *);
 
 void	 nbr_itimer(int, short, void *);
 void	 nbr_start_itimer(struct nbr *);
diff --git a/usr.sbin/ldpd/neighbor.c b/usr.sbin/ldpd/neighbor.c
index 04a700852d5..9ab7cdaa74a 100644
--- a/usr.sbin/ldpd/neighbor.c
+++ b/usr.sbin/ldpd/neighbor.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: neighbor.c,v 1.26 2013/05/31 14:10:10 claudio Exp $ */
+/*	$OpenBSD: neighbor.c,v 1.27 2013/06/01 01:34:57 claudio Exp $ */
 
 /*
  * Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
@@ -333,6 +333,15 @@ nbr_find_ldpid(u_int32_t rtr_id, u_int16_t lspace)
 	return (RB_FIND(nbr_id_head, &nbrs_by_id, &n));
 }
 
+int
+nbr_session_active_role(struct nbr *nbr)
+{
+	if (ntohl(ldpe_router_id()) > ntohl(nbr->addr.s_addr))
+		return 1;
+
+	return 0;
+}
+
 /* timers */
 
 /* Inactivity timer: timeout based on hellos */
@@ -445,7 +454,7 @@ nbr_idtimer(int fd, short event, void *arg)
 {
 	struct nbr *nbr = arg;
 
-	if (ntohl(nbr->addr.s_addr) >= ntohl(nbr->iface->addr.s_addr))
+	if (!nbr_session_active_role(nbr))
 		return;
 
 	log_debug("nbr_idtimer: neighbor ID %s peerid %lu", inet_ntoa(nbr->id),
@@ -519,12 +528,8 @@ nbr_connect_cb(int fd, short event, void *arg)
 int
 nbr_establish_connection(struct nbr *nbr)
 {
-	struct sockaddr_in	in;
-
-	bzero(&in, sizeof(in));
-	in.sin_family = AF_INET;
-	in.sin_port = htons(LDP_PORT);
-	in.sin_addr.s_addr = nbr->addr.s_addr;
+	struct sockaddr_in	local_sa;
+	struct sockaddr_in	remote_sa;
 
 	nbr->fd = socket(AF_INET, SOCK_STREAM, 0);
 	if (nbr->fd == -1) {
@@ -535,7 +540,26 @@ nbr_establish_connection(struct nbr *nbr)
 
 	session_socket_blockmode(nbr->fd, BM_NONBLOCK);
 
-	if (connect(nbr->fd, (struct sockaddr *)&in, sizeof(in)) == -1) {
+	bzero(&local_sa, sizeof(local_sa));
+	local_sa.sin_family = AF_INET;
+	local_sa.sin_port = htons(0);
+	local_sa.sin_addr.s_addr = ldpe_router_id();
+
+	if (bind(nbr->fd, (struct sockaddr *) &local_sa,
+	    sizeof(struct sockaddr_in)) == -1) {
+		log_debug("nbr_establish_connection: error while "
+		    "binding socket to %s", inet_ntoa(local_sa.sin_addr));
+		close(nbr->fd);
+		return (-1);
+	}
+
+	bzero(&remote_sa, sizeof(remote_sa));
+	remote_sa.sin_family = AF_INET;
+	remote_sa.sin_port = htons(LDP_PORT);
+	remote_sa.sin_addr.s_addr = nbr->addr.s_addr;
+
+	if (connect(nbr->fd, (struct sockaddr *)&remote_sa,
+	    sizeof(remote_sa)) == -1) {
 		if (errno == EINPROGRESS) {
 			event_set(&nbr->ev_connect, nbr->fd, EV_WRITE,
 			    nbr_connect_cb, nbr);