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| author | Philippe Guibert <philippe.guibert@6wind.com> | 2022-11-07 11:56:37 +0100 |
|---|---|---|
| committer | Mergify <37929162+mergify[bot]@users.noreply.github.com> | 2022-11-17 02:58:49 +0000 |
| commit | 56dd706e9b3a5eb790fa695e8f6f71e73b843aab (patch) | |
| tree | 26894b26ee099eac0275d52f8c4c374754c52315 | |
| parent | 23f40f230d1fe293eb519aafb0825444ea44f0e0 (diff) | |
bgpd: authorise to select bgp self peer prefix on rr case
This commit addresses an issue that happens when using bgp
peering with a rr client, with a received prefix which is the
local ip address of the bgp session.
When using bgp ipv4 unicast session, the local prefix is
received by a peer, and finds out that the proposed prefix
and its next-hop are the same. To avoid a route loop locally,
no nexthop entry is referenced for that prefix, and the route
will not be selected.
When the received peer is a route reflector, the prefix has
to be selected, even if the route can not be installed locally.
Fixes: ("fb8ae704615c") bgpd: prevent routes loop through itself
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
(cherry picked from commit f874552557cf2577ae91b297f422e307084f22d3)
| -rw-r--r-- | bgpd/bgp_route.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c index 9ec70ab3de..7104ee3d1d 100644 --- a/bgpd/bgp_route.c +++ b/bgpd/bgp_route.c @@ -3874,6 +3874,7 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id, int vnc_implicit_withdraw = 0; #endif int same_attr = 0; + const struct prefix *bgp_nht_param_prefix; /* Special case for BGP-LU - map LU safi to ordinary unicast safi */ if (orig_safi == SAFI_LABELED_UNICAST) @@ -3937,6 +3938,11 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id, if (aspath_get_last_as(attr->aspath) == bgp->as) do_loop_check = 0; + if (CHECK_FLAG(peer->af_flags[afi][safi], PEER_FLAG_REFLECTOR_CLIENT)) + bgp_nht_param_prefix = NULL; + else + bgp_nht_param_prefix = p; + /* AS path loop check. */ if (do_loop_check) { if (aspath_loop_check(attr->aspath, bgp->as) @@ -4445,8 +4451,8 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id, if (bgp_find_or_add_nexthop(bgp, bgp_nexthop, nh_afi, safi, pi, NULL, connected, - p) - || CHECK_FLAG(peer->flags, PEER_FLAG_IS_RFAPI_HD)) + bgp_nht_param_prefix) || + CHECK_FLAG(peer->flags, PEER_FLAG_IS_RFAPI_HD)) bgp_path_info_set_flag(dest, pi, BGP_PATH_VALID); else { @@ -4604,8 +4610,8 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id, nh_afi = BGP_ATTR_NH_AFI(afi, new->attr); if (bgp_find_or_add_nexthop(bgp, bgp, nh_afi, safi, new, NULL, - connected, p) - || CHECK_FLAG(peer->flags, PEER_FLAG_IS_RFAPI_HD)) + connected, bgp_nht_param_prefix) || + CHECK_FLAG(peer->flags, PEER_FLAG_IS_RFAPI_HD)) bgp_path_info_set_flag(dest, new, BGP_PATH_VALID); else { if (BGP_DEBUG(nht, NHT)) { |