This patch adds support to tcpdump(8) to decode Large BGP
Communities in human readable form.
Example:
[ snip ] BGP (UPDATE: (Path attributes: (ORIGIN[T] IGP)
(AS_PATH[T] 65000)
(NEXT_HOP[T] pxtr-2.meerval.net)
(COMMUNITIES[OT] 666:666 2914:0)
(LARGE_COMMUNITIES[OT] 2914:0:666 2914:4294927296:123))
(NLRI: 9.9.9.10/32)) (DF) (ttl 63, id 2806, len 138)
Kind regards,
Job
Index: src/usr.sbin/tcpdump/print-bgp.c
===================================================================
RCS file: /cvs/src/usr.sbin/tcpdump/print-bgp.c,v
retrieving revision 1.18
diff -u -p -u -r1.18 print-bgp.c
--- src/usr.sbin/tcpdump/print-bgp.c 20 Oct 2015 11:29:07 -0000 1.18
+++ src/usr.sbin/tcpdump/print-bgp.c 12 Oct 2016 16:09:51 -0000
@@ -134,6 +134,7 @@ struct bgp_attr {
#define BGPTYPE_EXTD_COMMUNITIES 16 /* RFC4360 */
#define BGPTYPE_AS4_PATH 17 /* RFC4893 */
#define BGPTYPE_AGGREGATOR4 18 /* RFC4893 */
+#define BGPTYPE_LARGE_COMMUNITIES 30 /*
draft-ietf-idr-large-community */
#define BGP_AS_SET 1
#define BGP_AS_SEQUENCE 2
@@ -265,7 +266,8 @@ static const char *bgpattr_type[] = {
"MULTI_EXIT_DISC", "LOCAL_PREF", "ATOMIC_AGGREGATE", "AGGREGATOR",
"COMMUNITIES", "ORIGINATOR_ID", "CLUSTER_LIST", "DPA",
"ADVERTISERS", "RCID_PATH", "MP_REACH_NLRI", "MP_UNREACH_NLRI",
- "EXTD_COMMUNITIES", "AS4_PATH", "AGGREGATOR4",
+ "EXTD_COMMUNITIES", "AS4_PATH", "AGGREGATOR4", NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, "LARGE_COMMUNITIES",
};
#define bgp_attr_type(x) \
num_or_str(bgpattr_type, \
@@ -544,6 +546,21 @@ bgp_attr_print(const struct bgp_attr *at
}
tlen -= 4;
p += 4;
+ }
+ break;
+ case BGPTYPE_LARGE_COMMUNITIES:
+ if (len == 0 || len % 12) {
+ printf(" invalid len");
+ break;
+ }
+ while (tlen>0) {
+ TCHECK2(p[0], 12);
+ printf(" %u:%u:%u",
+ EXTRACT_32BITS(p),
+ EXTRACT_32BITS(p + 4),
+ EXTRACT_32BITS(p + 8));
+ tlen -= 12;
+ p += 12;
}
break;
case BGPTYPE_ORIGINATOR_ID:
