add a parser for the capability announcements using the OPEN message as per

RFC 3392. we don't support any capability yet but this at least avoids one
session teardown and reestablishment when talking to peers which do support
capability announcement (as in: basically any) and we'll start supporting
some soon.

2 files changed, 60 insertions, 6 deletions

diff --git a/usr.sbin/bgpd/session.c b/usr.sbin/bgpd/session.c
index bf6ba8426b4..3c201ba6c70 100644
--- a/usr.sbin/bgpd/session.c
+++ b/usr.sbin/bgpd/session.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: session.c,v 1.125 2004/03/05 14:09:55 henning Exp $ */
+/*	$OpenBSD: session.c,v 1.126 2004/03/05 20:25:30 henning Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -75,6 +75,7 @@ int	parse_open(struct peer *);
 int	parse_update(struct peer *);
 int	parse_notification(struct peer *);
 int	parse_keepalive(struct peer *);
+int	parse_capabilities(struct peer *, u_char *, u_int16_t);
 void	session_dispatch_imsg(struct imsgbuf *, int);
 void	session_up(struct peer *);
 void	session_down(struct peer *);
@@ -1442,11 +1443,11 @@ parse_open(struct peer *peer)
 			return (-1);
 		}
 		memcpy(&op_type, p, sizeof(op_type));
-		p++;
-		plen--;
+		p += sizeof(op_type);
+		plen -= sizeof(op_type);
 		memcpy(&op_len, p, sizeof(op_len));
-		p++;
-		plen--;
+		p += sizeof(op_type);
+		plen -= sizeof(op_type);
 		if (op_len > 0) {
 			if (plen < op_len) {
 				log_peer_warnx(&peer->conf,
@@ -1463,6 +1464,15 @@ parse_open(struct peer *peer)
 			op_val = NULL;
 
 		switch (op_type) {
+		case OPT_PARAM_CAPABILITIES:		/* RFC 3392 */
+			if (parse_capabilities(peer, op_val, op_len) == -1) {
+				session_notification(peer, ERR_OPEN, 0,
+				    NULL, 0);
+				change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
+				return (-1);
+			}
+			break;
+		case OPT_PARAM_AUTH:			/* deprecated */
 		default:
 			/*
 			 * unsupported type
@@ -1548,6 +1558,44 @@ parse_notification(struct peer *peer)
 	return (0);
 }
 
+int
+parse_capabilities(struct peer *peer, u_char *d, u_int16_t dlen)
+{
+	u_int16_t	 len;
+	u_int8_t	 capa_code;
+	u_int8_t	 capa_len;
+	void		*capa_val;
+
+	len = dlen;
+	while (len > 0) {
+		if (len < 2)
+			return (-1);
+		memcpy(&capa_code, d, sizeof(capa_code));
+		d += sizeof(capa_code);
+		len -= sizeof(capa_code);
+		memcpy(&capa_len, d, sizeof(capa_len));
+		d += sizeof(capa_len);
+		len -= sizeof(capa_len);
+		if (capa_len > 0) {
+			if (len < capa_len)
+				return (-1);
+			capa_val = d;
+			d += capa_len;
+			len -= capa_len;
+		} else
+			capa_val = NULL;
+
+		switch (capa_code) {
+		default:
+			log_peer_warnx(&peer->conf, "got capability %u len %u",
+			    capa_code, capa_len);
+			break;
+		}
+	}
+
+	return (0);
+}
+
 void
 session_dispatch_imsg(struct imsgbuf *ibuf, int idx)
 {
diff --git a/usr.sbin/bgpd/session.h b/usr.sbin/bgpd/session.h
index ebc28f7d9b1..766826469df 100644
--- a/usr.sbin/bgpd/session.h
+++ b/usr.sbin/bgpd/session.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: session.h,v 1.32 2004/03/01 16:49:24 claudio Exp $ */
+/*	$OpenBSD: session.h,v 1.33 2004/03/05 20:25:30 henning Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -87,6 +87,12 @@ enum suberr_open {
 	ERR_OPEN_HOLDTIME
 };
 
+enum opt_params {
+	OPT_PARAM_NONE,
+	OPT_PARAM_AUTH,
+	OPT_PARAM_CAPABILITIES
+};
+
 struct msg_header {
 	u_char			 marker[16];
 	u_int16_t		 len;