Merge pull request #15162 from opensourcerouting/fix/aspath4_set_flag

bgpd: Set capability received flag only after sanity checks

bgpd/bgp_open.c

@@ -622,17 +622,17 @@ static int bgp_capability_llgr(struct peer *peer,
 /* Unlike other capability parsing routines, this one returns 0 on error */
 static as_t bgp_capability_as4(struct peer *peer, struct capability_header *hdr)
 {
-	SET_FLAG(peer->cap, PEER_CAP_AS4_RCV);
-
 	if (hdr->length != CAPABILITY_CODE_AS4_LEN) {
 		flog_err(EC_BGP_PKT_OPEN,
 			 "%s AS4 capability has incorrect data length %d",
 			 peer->host, hdr->length);
-		return 0;
+		return -1;
 	}
 
 	as_t as4 = stream_getl(BGP_INPUT(peer));
 
+	SET_FLAG(peer->cap, PEER_CAP_AS4_RCV);
+
 	if (BGP_DEBUG(as4, AS4))
 		zlog_debug(
 			"%s [AS4] about to set cap PEER_CAP_AS4_RCV, got as4 %u",
@@ -662,8 +662,6 @@ static int bgp_capability_addpath(struct peer *peer,
 	struct stream *s = BGP_INPUT(peer);
 	size_t end = stream_get_getp(s) + hdr->length;
 
-	SET_FLAG(peer->cap, PEER_CAP_ADDPATH_RCV);
-
 	/* Verify length is a multiple of 4 */
 	if (hdr->length % CAPABILITY_CODE_ADDPATH_LEN) {
 		flog_warn(
@@ -673,6 +671,8 @@ static int bgp_capability_addpath(struct peer *peer,
 		return -1;
 	}
 
+	SET_FLAG(peer->cap, PEER_CAP_ADDPATH_RCV);
+
 	while (stream_get_getp(s) + CAPABILITY_CODE_ADDPATH_LEN <= end) {
 		afi_t afi;
 		safi_t safi;
@@ -818,8 +818,6 @@ static int bgp_capability_hostname(struct peer *peer,
 	size_t end = stream_get_getp(s) + hdr->length;
 	uint8_t len;
 
-	SET_FLAG(peer->cap, PEER_CAP_HOSTNAME_RCV);
-
 	len = stream_getc(s);
 	if (stream_get_getp(s) + len > end) {
 		flog_warn(
@@ -877,6 +875,8 @@ static int bgp_capability_hostname(struct peer *peer,
 		peer->domainname = XSTRDUP(MTYPE_BGP_PEER_HOST, str);
 	}
 
+	SET_FLAG(peer->cap, PEER_CAP_HOSTNAME_RCV);
+
 	if (bgp_debug_neighbor_events(peer)) {
 		zlog_debug("%s received hostname %s, domainname %s", peer->host,
 			   peer->hostname, peer->domainname);
@@ -887,14 +887,16 @@ static int bgp_capability_hostname(struct peer *peer,
 
 static int bgp_capability_role(struct peer *peer, struct capability_header *hdr)
 {
-	SET_FLAG(peer->cap, PEER_CAP_ROLE_RCV);
 	if (hdr->length != CAPABILITY_CODE_ROLE_LEN) {
 		flog_warn(EC_BGP_CAPABILITY_INVALID_LENGTH,
 			  "Role: Received invalid length %d", hdr->length);
 		return -1;
 	}
+
 	uint8_t role = stream_getc(BGP_INPUT(peer));
 
+	SET_FLAG(peer->cap, PEER_CAP_ROLE_RCV);
+
 	peer->remote_role = role;
 	return 0;
 }

tests/bgpd/test_aspath.c

@@ -653,7 +653,7 @@ static struct aspath_tests {
 		"8466 3 52737 4096",
 		AS4_DATA,
 		-1,
-		PEER_CAP_AS4_RCV,
+		0,
 		{
 			COMMON_ATTRS,
 			BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL,
@@ -685,7 +685,7 @@ static struct aspath_tests {
 		"8466 3 52737 4096",
 		AS4_DATA,
 		-1,
-		PEER_CAP_AS4_RCV | PEER_CAP_AS4_ADV,
+		0,
 		{
 			COMMON_ATTRS,
 			BGP_ATTR_FLAG_TRANS,
@@ -701,7 +701,7 @@ static struct aspath_tests {
 		"8466 3 52737 4096",
 		AS4_DATA,
 		-1,
-		PEER_CAP_AS4_RCV | PEER_CAP_AS4_ADV,
+		0,
 		{
 			COMMON_ATTRS,
 			BGP_ATTR_FLAG_TRANS,
@@ -717,7 +717,7 @@ static struct aspath_tests {
 		"8466 3 52737 4096",
 		AS4_DATA,
 		-1,
-		PEER_CAP_AS4_RCV | PEER_CAP_AS4_ADV,
+		0,
 		{
 			COMMON_ATTRS,
 			BGP_ATTR_FLAG_TRANS,
@@ -733,7 +733,7 @@ static struct aspath_tests {
 		"8466 3 52737 4096",
 		AS4_DATA,
 		-1,
-		PEER_CAP_AS4_RCV | PEER_CAP_AS4_ADV,
+		0,
 		{
 			COMMON_ATTRS,
 			BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL,

tests/bgpd/test_capability.c

@@ -617,6 +617,7 @@ static struct test_segment misc_segments[] =
 			},
 			2,
 			SHOULD_ERR,
+			-1,
 		},
 		{
 			"dyn-empty",