In bgpd we do not follow the RFC8050 encoding for RIB_GENERIC_ADDPATH.
Mainly because it does not fit the way the code works and also because the
only other BGP implementation that seems to care about RIB_GENERIC_ADDPATH
does it the same way.
Because of this it makes no sense to parse RIB_GENERIC_ADDPATH strictly
per RFC8050 but instead parse it the way it is implemented.
While there cleanup some unused variables.
--
:wq Claudio
Index: mrtparser.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpctl/mrtparser.c,v
retrieving revision 1.15
diff -u -p -r1.15 mrtparser.c
--- mrtparser.c 27 Jul 2021 07:42:37 -0000 1.15
+++ mrtparser.c 22 Sep 2021 10:22:54 -0000
@@ -103,10 +103,8 @@ mrt_parse(int fd, struct mrt_parser *p,
struct mrt_bgp_state *s;
struct mrt_bgp_msg *m;
void *msg;
- int addpath;
while ((msg = mrt_read_msg(fd, &h))) {
- addpath = 0;
switch (ntohs(h.type)) {
case MSG_NULL:
case MSG_START:
@@ -376,7 +374,7 @@ mrt_parse_v2_rib(struct mrt_hdr *hdr, vo
u_int32_t snum, path_id = 0;
u_int16_t cnt, i, afi;
u_int8_t safi, aid;
- int ret, addpath = 0;
+ int ret;
if (len < sizeof(snum) + 1)
return NULL;
@@ -417,6 +415,11 @@ mrt_parse_v2_rib(struct mrt_hdr *hdr, vo
goto fail;
break;
case MRT_DUMP_V2_RIB_GENERIC_ADDPATH:
+ /*
+ * RFC8050 handling for add-path has special handling for
+ * RIB_GENERIC_ADDPATH but nobody implements it that way.
+ * So just use the same way as for the other _ADDPATH types.
+ */
r->add_path = 1;
/* FALLTHROUGH */
case MRT_DUMP_V2_RIB_GENERIC:
@@ -434,16 +437,6 @@ mrt_parse_v2_rib(struct mrt_hdr *hdr, vo
if ((aid = mrt_afi2aid(afi, safi, verbose)) == AID_UNSPEC)
goto fail;
- /* RFC8050 handling for add-path */
- if (r->add_path) {
- if (len < sizeof(path_id))
- goto fail;
- memcpy(&path_id, b, sizeof(path_id));
- b += sizeof(path_id);
- len -= sizeof(path_id);
- path_id = ntohl(path_id);
- }
-
/* prefix */
ret = mrt_extract_prefix(b, len, aid, &r->prefix,
&r->prefixlen, verbose);
@@ -487,12 +480,9 @@ mrt_parse_v2_rib(struct mrt_hdr *hdr, vo
len -= sizeof(otm);
entries[i].originated = ntohl(otm);
- /* RFC8050 handling for add-path */
- if (r->add_path &&
- ntohs(hdr->subtype) != MRT_DUMP_V2_RIB_GENERIC_ADDPATH) {
+ if (r->add_path) {
if (len < sizeof(path_id) + sizeof(alen))
goto fail;
- addpath = 0;
memcpy(&path_id, b, sizeof(path_id));
b += sizeof(path_id);
len -= sizeof(path_id);
