From a73b0f88c7715bfcf5dc8ffd46d2fd0bbc9a8aff Mon Sep 17 00:00:00 2001 From: Donatas Abraitis Date: Tue, 21 Jan 2025 21:17:39 +0200 Subject: [PATCH] bgpd: Send non-transitive extended communities from/to OAD peers draft-uttaro-idr-bgp-oad says: Extended communities which are non-transitive across an AS boundary MAY be advertised over an EBGP-OAD session if allowed by explicit policy configuration. If allowed, all the members of the OAD SHOULD be configured to use the same criteria. For example, the Origin Validation State Extended Community, defined as non-transitive in [RFC8097], can be advertised to peers in the same OAD. Signed-off-by: Donatas Abraitis (cherry picked from commit f2759c46ceda2a5f13b40213381baf71997b6b87) # Conflicts: # bgpd/bgp_route.c --- bgpd/bgp_route.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c index aa2c3a6a56..e39a97f84a 100644 --- a/bgpd/bgp_route.c +++ b/bgpd/bgp_route.c @@ -2700,6 +2700,7 @@ bool subgroup_announce_check(struct bgp_dest *dest, struct bgp_path_info *pi, if (nh_reset && bgp_path_info_mpath_chkwtd(bgp, pi) && (cum_bw = bgp_path_info_mpath_cumbw(pi)) != 0 && +<<<<<<< HEAD !CHECK_FLAG(attr->rmap_change_flags, BATTR_RMAP_LINK_BW_SET)) bgp_attr_set_ecommunity( attr, @@ -2708,6 +2709,94 @@ bool subgroup_announce_check(struct bgp_dest *dest, struct bgp_path_info *pi, CHECK_FLAG( peer->flags, PEER_FLAG_DISABLE_LINK_BW_ENCODING_IEEE))); +======= + !CHECK_FLAG(attr->rmap_change_flags, BATTR_RMAP_LINK_BW_SET)) { + if (CHECK_FLAG(peer->flags, PEER_FLAG_EXTENDED_LINK_BANDWIDTH)) + bgp_attr_set_ipv6_ecommunity( + attr, + ecommunity_replace_linkbw(bgp->as, + bgp_attr_get_ipv6_ecommunity( + attr), + cum_bw, false, true)); + else + bgp_attr_set_ecommunity( + attr, + ecommunity_replace_linkbw( + bgp->as, bgp_attr_get_ecommunity(attr), + cum_bw, + CHECK_FLAG(peer->flags, + PEER_FLAG_DISABLE_LINK_BW_ENCODING_IEEE), + false)); + } + + /* + * Adjust AIGP for propagation when the nexthop is set to ourselves, + * e.g., using "set ip nexthop peer-address" or when advertising to + * EBGP. Note in route reflection the nexthop is usually unmodified + * and the AIGP should not be adjusted in that case. + */ + if (CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_AIGP)) && AIGP_TRANSMIT_ALLOWED(peer)) { + if (nh_reset || + CHECK_FLAG(attr->rmap_change_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS)) { + uint64_t aigp = bgp_aigp_metric_total(pi); + + bgp_attr_set_aigp_metric(attr, aigp); + } + } + + /* Extended communities can be transitive and non-transitive. + * If the extended community is non-transitive, strip it off, + * unless it's a locally originated route (static, aggregate, + * redistributed, etc.). + * draft-uttaro-idr-bgp-oad says: + * Extended communities which are non-transitive across an AS + * boundary MAY be advertised over an EBGP-OAD session if allowed + * by explicit policy configuration. If allowed, all the members + * of the OAD SHOULD be configured to use the same criteria. + * For example, the Origin Validation State Extended Community, + * defined as non-transitive in [RFC8097], can be advertised to + * peers in the same OAD. + */ + if (from->sort == BGP_PEER_EBGP && from->sub_sort != BGP_PEER_EBGP_OAD && + peer->sort == BGP_PEER_EBGP && peer->sub_sort != BGP_PEER_EBGP_OAD && + pi->sub_type == BGP_ROUTE_NORMAL) { + struct ecommunity *new_ecomm; + struct ecommunity *old_ecomm; + + old_ecomm = bgp_attr_get_ecommunity(attr); + if (old_ecomm) { + new_ecomm = ecommunity_dup(old_ecomm); + if (ecommunity_strip_non_transitive(new_ecomm)) { + bgp_attr_set_ecommunity(attr, new_ecomm); + if (!old_ecomm->refcnt) + ecommunity_free(&old_ecomm); + if (bgp_debug_update(NULL, p, subgrp->update_group, 0)) + zlog_debug("%pBP: %pFX stripped non-transitive extended communities", + peer, p); + } else { + ecommunity_free(&new_ecomm); + } + } + + /* Extended link-bandwidth communities are encoded as IPv6 + * address-specific extended communities. + */ + old_ecomm = bgp_attr_get_ipv6_ecommunity(attr); + if (old_ecomm) { + new_ecomm = ecommunity_dup(old_ecomm); + if (ecommunity_strip_non_transitive(new_ecomm)) { + bgp_attr_set_ipv6_ecommunity(attr, new_ecomm); + if (!old_ecomm->refcnt) + ecommunity_free(&old_ecomm); + if (bgp_debug_update(NULL, p, subgrp->update_group, 0)) + zlog_debug("%pBP: %pFX stripped non-transitive ipv6 extended communities", + peer, p); + } else { + ecommunity_free(&new_ecomm); + } + } + } +>>>>>>> f2759c46c (bgpd: Send non-transitive extended communities from/to OAD peers) return true; } -- 2.39.5