bgpd: Pass non-transitive ext-communities between Route Server and RS clients

https://datatracker.ietf.org/doc/html/rfc7947#section-2.2

Optional recognized and unrecognized BGP attributes,
   whether transitive or non-transitive, SHOULD NOT be updated by the
   route server (unless enforced by local IXP operator configuration)
   and SHOULD be passed on to other route server clients.

By default LB ext-community works with iBGP peers. When we receive a route
from eBGP peer, we can send LB ext-community to iBGP peers.

With this patch, allow sending LB ext-community to iBGP/eBGP peers if they
are set as RS clients.

FRR does not send non-transitive ext-communities to eBGP peers, but for
example GoBGP sends and if it's set as RS client, we should pass those attributes
towards another RS client.

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
This commit is contained in:
Donatas Abraitis 2022-04-13 20:40:30 +03:00
parent bd751c0700
commit b17d5444f4

View File

@ -4177,9 +4177,14 @@ bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *peer,
if (CHECK_FLAG(peer->af_flags[afi][safi], PEER_FLAG_SEND_EXT_COMMUNITY)
&& (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES))) {
struct ecommunity *ecomm = bgp_attr_get_ecommunity(attr);
bool transparent = CHECK_FLAG(peer->af_flags[afi][safi],
PEER_FLAG_RSERVER_CLIENT) &&
from &&
CHECK_FLAG(from->af_flags[afi][safi],
PEER_FLAG_RSERVER_CLIENT);
if (peer->sort == BGP_PEER_IBGP
|| peer->sort == BGP_PEER_CONFED) {
if (peer->sort == BGP_PEER_IBGP ||
peer->sort == BGP_PEER_CONFED || transparent) {
if (ecomm->size * 8 > 255) {
stream_putc(s,
BGP_ATTR_FLAG_OPTIONAL