bgpd: add multiple paths support for draft ietf bgp4v2 in nlriTable

There is no support for dumping multiple paths for the same prefix.
The current implementation only takes the first available entry.

Fix this by walking over the list of available paths, ordered by peer.
The nlri index is set gradually for each path.

Signed-off-by: Francois Dumontet <[email protected]>

Author: fdumontet6WIND

bgpd/bgp_snmp_bgp4v2.c

@@ -446,6 +446,8 @@ bgp4v2PathAttrLookup(struct variable *v, oid name[], size_t *length,
 	size_t afi_len;
 	long prefix_type = 0;
 	long peer_addr_type = 0;
+	long nrli_index = 1;
+	long cur_index = 0;
 
 	/* Bgp4V2AddressFamilyIdentifierTC limited to IPv6 */
 	if (name[namelen - 1] > IANA_AFI_IPV6)
@@ -455,12 +457,17 @@ bgp4v2PathAttrLookup(struct variable *v, oid name[], size_t *length,
 	assert(IS_VALID_AFI(afi));
 
 #define BGP_NLRI_ENTRY_OFFSET namelen
+#define BGP4V2_NLRI_V4_V4_OFFSET IN_ADDR_SIZE + IN_ADDR_SIZE + 5
+#define BGP4V2_NLRI_V4_V6_OFFSET IN_ADDR_SIZE + IN6_ADDR_SIZE + 5
+#define BGP4V2_NLRI_V6_V6_OFFSET IN6_ADDR_SIZE + IN6_ADDR_SIZE + 5
 
 
 	sockunion_init(&su);
 
 	if (exact) {
-		if (*length - namelen != BGP_NLRI_ENTRY_OFFSET)
+		if (*length - namelen != BGP4V2_NLRI_V4_V4_OFFSET &&
+		    *length - namelen != BGP4V2_NLRI_V4_V6_OFFSET &&
+		    *length - namelen != BGP4V2_NLRI_V6_V6_OFFSET)
 			return NULL;
 
 		/* Set OID offset for prefix type */
@@ -504,21 +511,29 @@ bgp4v2PathAttrLookup(struct variable *v, oid name[], size_t *length,
 		su.sin.sin_family = family;
 
 		/* get bgp4V2PeerRemoteAddr*/
-		if (family == AF_INET)
+		if (family == AF_INET) {
 			oid2in_addr(offset, IN_ADDR_SIZE, &su.sin.sin_addr);
-		else
+			offset += IN_ADDR_SIZE;
+		} else {
 			oid2in6_addr(offset, &su.sin6.sin6_addr);
+			offset += IN6_ADDR_SIZE;
+		}
 
-		/* bgp4V2NlriIndex currently ignored */
+		/* bgp4V2NlriIndex */
+		nrli_index = *offset;
+		offset++;
 
 		/* Lookup node */
 		dest = bgp_node_lookup(bgp->rib[afi][safi], addr);
 		if (dest) {
 			for (path = bgp_dest_get_bgp_path_info(dest); path;
 			     path = path->next)
 				if (sockunion_same(&path->peer->connection->su,
-						   &su))
-					return path;
+						   &su)) {
+					cur_index++;
+					if (cur_index == nrli_index)
+						return path;
+				}
 
 			bgp_dest_unlock_node(dest);
 		}
@@ -573,7 +588,7 @@ bgp4v2PathAttrLookup(struct variable *v, oid name[], size_t *length,
 		offsetlen--;
 
 		/* get node */
-		dest = bgp_node_get(bgp->rib[afi][safi], addr);
+		dest = bgp_node_lookup(bgp->rib[afi][safi], addr);
 	}
 
 	if (!dest)
@@ -593,22 +608,31 @@ bgp4v2PathAttrLookup(struct variable *v, oid name[], size_t *length,
 			family = AF_INET6;
 		offset++;
 
-		if (family == AF_INET)
+		if (family == AF_INET) {
 			oid2in_addr(offset, IN_ADDR_SIZE, &paddr.ip._v4_addr);
-		else
+			offset += IN_ADDR_SIZE;
+		} else {
 			oid2in6_addr(offset, &paddr.ip._v6_addr);
+			offset += IN6_ADDR_SIZE;
+		}
+		/* get bgp4V2NlriIndex	*/
+		nrli_index = *offset;
+		offset++;
+
 	} else {
 		/* default case  start with ipv4*/
 		if (afi == AFI_IP)
 			family = AF_INET;
 		else
 			family = AF_INET6;
 		memset(&paddr.ip, 0, sizeof(paddr.ip));
+		nrli_index = 1;
 	}
 
 	do {
 		min = NULL;
 		min_family = 0;
+		cur_index = 0;
 
 		for (path = bgp_dest_get_bgp_path_info(dest); path;
 		     path = path->next) {
@@ -618,19 +642,44 @@ bgp4v2PathAttrLookup(struct variable *v, oid name[], size_t *length,
 			if (path_family < family)
 				continue;
 
-			if (family == AF_INET
-			    && IPV4_ADDR_CMP(&paddr.ip._v4_addr,
-					     &path->peer->connection->su.sin.sin_addr)
-				       >= 0)
+			if (family == AF_INET &&
+			    IPV4_ADDR_CMP(&paddr.ip._v4_addr,
+					  &path->peer->connection->su.sin
+						   .sin_addr) > 0)
 				continue;
-			else if (family == AF_INET6
-				 && IPV6_ADDR_CMP(
-					    &paddr.ip._v6_addr,
-					    &path->peer->connection->su.sin6.sin6_addr)
-					    >= 0)
+			else if (family == AF_INET6 &&
+				 IPV6_ADDR_CMP(&paddr.ip._v6_addr,
+					       &path->peer->connection->su.sin6
+							.sin6_addr) > 0)
 				continue;
 
-			/* first valid path its the  min*/
+			if (family == AF_INET &&
+			    IPV4_ADDR_CMP(&paddr.ip._v4_addr,
+					  &path->peer->connection->su.sin
+						   .sin_addr) == 0) {
+				if (cur_index == nrli_index) {
+					min = path;
+					min_family = family;
+					nrli_index++;
+					break;
+				}
+				cur_index++;
+				continue;
+			} else if (family == AF_INET6 &&
+				   IPV6_ADDR_CMP(&paddr.ip._v6_addr,
+						 &path->peer->connection->su
+							  .sin6.sin6_addr) == 0) {
+				if (cur_index == nrli_index) {
+					min = path;
+					min_family = family;
+					nrli_index++;
+					break;
+				}
+				cur_index++;
+				continue;
+			}
+
+			/* first valid path its the  min peer addr*/
 			if (!min) {
 				min = path;
 				min_family = path_family;
@@ -706,7 +755,7 @@ bgp4v2PathAttrLookup(struct variable *v, oid name[], size_t *length,
 
 			/* Encode bgp4V2NlriIndex*/
 
-			*offset = 1;
+			*offset = nrli_index;
 			offset++;
 
 			*length = offset - name;
@@ -720,6 +769,7 @@ bgp4v2PathAttrLookup(struct variable *v, oid name[], size_t *length,
 		}
 
 		memset(&paddr.ip, 0, sizeof(paddr.ip));
+		nrli_index = 1;
 
 	} while ((dest = bgp_route_next(dest)));