1 files changed, 19 insertions, 29 deletions

diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
index 2f0751a5f0..0870748f7e 100644
--- a/bgpd/bgp_attr.c
+++ b/bgpd/bgp_attr.c
@@ -1497,8 +1497,10 @@ static int bgp_attr_aspath(struct bgp_attr_parser_args *args)
 	 * peer with AS4 => will get 4Byte ASnums
 	 * otherwise, will get 16 Bit
 	 */
-	attr->aspath = aspath_parse(peer->curr, length,
-				    CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV));
+	attr->aspath = aspath_parse(
+		peer->curr, length,
+		CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV)
+			&& CHECK_FLAG(peer->cap, PEER_CAP_AS4_ADV));
 
 	/* In case of IBGP, length will be zero. */
 	if (!attr->aspath) {
@@ -1509,16 +1511,6 @@ static int bgp_attr_aspath(struct bgp_attr_parser_args *args)
 					  0);
 	}
 
-	/* Codification of AS 0 Processing */
-	if (aspath_check_as_zero(attr->aspath)) {
-		flog_err(
-			EC_BGP_ATTR_MAL_AS_PATH,
-			"Malformed AS path, AS number is 0 in the path from %s",
-			peer->host);
-		return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_MAL_AS_PATH,
-					  0);
-	}
-
 	/* Set aspath attribute flag. */
 	attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AS_PATH);
 
@@ -1558,6 +1550,15 @@ static bgp_attr_parse_ret_t bgp_attr_aspath_check(struct peer *const peer,
 		}
 	}
 
+	/* Codification of AS 0 Processing */
+	if (peer->sort == BGP_PEER_EBGP && aspath_check_as_zero(attr->aspath)) {
+		flog_err(
+			EC_BGP_ATTR_MAL_AS_PATH,
+			"Malformed AS path, AS number is 0 in the path from %s",
+			peer->host);
+		return BGP_ATTR_PARSE_WITHDRAW;
+	}
+
 	/* local-as prepend */
 	if (peer->change_local_as
 	    && !CHECK_FLAG(peer->flags, PEER_FLAG_LOCAL_AS_NO_PREPEND)) {
@@ -1590,16 +1591,6 @@ static int bgp_attr_as4_path(struct bgp_attr_parser_args *args,
 					  0);
 	}
 
-	/* Codification of AS 0 Processing */
-	if (aspath_check_as_zero(*as4_path)) {
-		flog_err(
-			EC_BGP_ATTR_MAL_AS_PATH,
-			"Malformed AS path, AS number is 0 in the path from %s",
-			peer->host);
-		return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_MAL_AS_PATH,
-					  0);
-	}
-
 	/* Set aspath attribute flag. */
 	attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AS4_PATH);
 
@@ -2926,11 +2917,8 @@ static bgp_attr_parse_ret_t bgp_attr_unknown(struct bgp_attr_parser_args *args)
 	if (!transit)
 		transit = XCALLOC(MTYPE_TRANSIT, sizeof(struct transit));
 
-	if (transit->val)
-		transit->val = XREALLOC(MTYPE_TRANSIT_VAL, transit->val,
-					transit->length + total);
-	else
-		transit->val = XMALLOC(MTYPE_TRANSIT_VAL, total);
+	transit->val = XREALLOC(MTYPE_TRANSIT_VAL, transit->val,
+				transit->length + total);
 
 	memcpy(transit->val + transit->length, startp, total);
 	transit->length += total;
@@ -3317,7 +3305,8 @@ bgp_attr_parse_ret_t bgp_attr_parse(struct peer *peer, struct attr *attr,
 	}
 
 	/* Check all mandatory well-known attributes are present */
-	if ((ret = bgp_attr_check(peer, attr)) < 0)
+	ret = bgp_attr_check(peer, attr);
+	if (ret < 0)
 		goto done;
 
 	/*
@@ -3758,7 +3747,8 @@ bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *peer,
 	struct aspath *aspath;
 	int send_as4_path = 0;
 	int send_as4_aggregator = 0;
-	bool use32bit = CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV);
+	bool use32bit = CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV)
+			&& CHECK_FLAG(peer->cap, PEER_CAP_AS4_ADV);
 
 	if (!bgp)
 		bgp = peer->bgp;