bgpd: fix handling of AS path data
* bgpd/bgp_aspath.c
* assegments_parse(): add handling of AS4_PATH input, update bounds
checks, add check for AS segment type
* aspath_parse(): add handling of AS4_PATH input, expect
assegments_parse() to do length checking
* aspath_empty(): update for the new function prototype
* bgpd/bgp_aspath.h: ditto
* tests/aspath_test.c: ditto
* bgpd/bgp_attr.c
* bgp_attr_aspath(): add handling of AS4_PATH input, update flags
checks, change returned type
* bgp_attr_as4_path(): discard, superseded by bgp_attr_aspath()
* bgp_attr_parse(): update respectively
diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
index 5e7536a..3996afd 100644
--- a/bgpd/bgp_attr.c
+++ b/bgpd/bgp_attr.c
@@ -807,54 +807,78 @@
return 0;
}
-
-/* Parse AS path information. This function is wrapper of
- aspath_parse. */
-static int
+/* Parse AS path information. This function is wrapper of aspath_parse.
+ *
+ * Parses AS_PATH or AS4_PATH.
+ *
+ * Returns: if valid: address of struct aspath in the hash of known aspaths,
+ * with reference count incremented.
+ * else: NULL
+ *
+ * NB: empty AS path (length == 0) is valid. The returned struct aspath will
+ * have segments == NULL and str == zero length string (unique).
+ */
+static struct aspath *
bgp_attr_aspath (struct peer *peer, bgp_size_t length,
- struct attr *attr, u_char flag, u_char *startp)
+ struct attr *attr, u_char flag, u_char *startp, int as4_path)
{
- bgp_size_t total;
+ u_char require ;
+ struct aspath *asp ;
- total = length + (CHECK_FLAG (flag, BGP_ATTR_FLAG_EXTLEN) ? 4 : 3);
+ /* Check the attribute flags */
+ require = as4_path ? BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS
+ : BGP_ATTR_FLAG_TRANS ;
- /* Flag check. */
- if (CHECK_FLAG (flag, BGP_ATTR_FLAG_OPTIONAL)
- || ! CHECK_FLAG (flag, BGP_ATTR_FLAG_TRANS))
+ if ((flag & (BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS)) != require)
{
+ const char* path_type ;
+ bgp_size_t total;
+
+ path_type = as4_path ? "AS4_PATH" : "AS_PATH" ;
+
+ if (!CHECK_FLAG(flag, BGP_ATTR_FLAG_TRANS))
zlog (peer->log, LOG_ERR,
- "As-Path attribute flag isn't transitive %d", flag);
+ "%s attribute flag isn't transitive %d", path_type, flag) ;
+
+ if ((flag & BGP_ATTR_FLAG_OPTIONAL) != (require & BGP_ATTR_FLAG_OPTIONAL))
+ zlog (peer->log, LOG_ERR,
+ "%s attribute flag must %sbe optional %d", path_type,
+ (flag & BGP_ATTR_FLAG_OPTIONAL) ? "not " : "", flag) ;
+
+ total = length + (CHECK_FLAG (flag, BGP_ATTR_FLAG_EXTLEN) ? 4 : 3);
+
bgp_notify_send_with_data (peer,
BGP_NOTIFY_UPDATE_ERR,
BGP_NOTIFY_UPDATE_ATTR_FLAG_ERR,
startp, total);
- return -1;
- }
- /*
- * peer with AS4 => will get 4Byte ASnums
- * otherwise, will get 16 Bit
+ return NULL ;
+ } ;
+
+ /* Parse the AS_PATH/AS4_PATH body.
+ *
+ * For AS_PATH peer with AS4 => 4Byte ASN otherwise 2Byte ASN
+ * AS4_PATH 4Byte ASN
*/
- attr->aspath = aspath_parse (peer->ibuf, length,
- CHECK_FLAG (peer->cap, PEER_CAP_AS4_RCV));
+ asp = aspath_parse (peer->ibuf, length,
+ as4_path || CHECK_FLAG (peer->cap, PEER_CAP_AS4_RCV), as4_path) ;
- /* In case of IBGP, length will be zero. */
- if (! attr->aspath)
+ if (asp != NULL)
+ {
+ attr->flag |= ATTR_FLAG_BIT (as4_path ? BGP_ATTR_AS4_PATH
+ : BGP_ATTR_AS_PATH) ;
+ }
+ else
{
zlog (peer->log, LOG_ERR, "Malformed AS path length is %d", length);
+
+ /* TODO: should BGP_NOTIFY_UPDATE_MAL_AS_PATH be sent for AS4_PATH ?? */
bgp_notify_send (peer,
BGP_NOTIFY_UPDATE_ERR,
BGP_NOTIFY_UPDATE_MAL_AS_PATH);
- return -1;
- }
+ } ;
- /* Forward pointer. */
-/* stream_forward_getp (peer->ibuf, length);*/
-
- /* Set aspath attribute flag. */
- attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_AS_PATH);
-
- return 0;
+ return asp ;
}
static int bgp_attr_aspath_check( struct peer *peer,
@@ -912,21 +936,6 @@
}
-/* Parse AS4 path information. This function is another wrapper of
- aspath_parse. */
-static int
-bgp_attr_as4_path (struct peer *peer, bgp_size_t length,
- struct attr *attr, struct aspath **as4_path)
-{
- *as4_path = aspath_parse (peer->ibuf, length, 1);
-
- /* Set aspath attribute flag. */
- if (as4_path)
- attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_AS4_PATH);
-
- return 0;
-}
-
/* Nexthop attribute. */
static int
bgp_attr_nexthop (struct peer *peer, bgp_size_t length,
@@ -1657,10 +1666,12 @@
ret = bgp_attr_origin (peer, length, attr, flag, startp);
break;
case BGP_ATTR_AS_PATH:
- ret = bgp_attr_aspath (peer, length, attr, flag, startp);
+ attr->aspath = bgp_attr_aspath (peer, length, attr, flag, startp, 0);
+ ret = attr->aspath ? 0 : -1 ;
break;
case BGP_ATTR_AS4_PATH:
- ret = bgp_attr_as4_path (peer, length, attr, &as4_path );
+ as4_path = bgp_attr_aspath (peer, length, attr, flag, startp, 1);
+ ret = as4_path ? 0 : -1 ;
break;
case BGP_ATTR_NEXT_HOP:
ret = bgp_attr_nexthop (peer, length, attr, flag, startp);