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 <donatas@opensourcerouting.org>
(cherry picked from commit f2759c46ceda2a5f13b40213381baf71997b6b87)

# Conflicts:
#	bgpd/bgp_route.c

diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index aa2c3a6a560e376d7bf62b7adc5e958b70d78a6a..e39a97f84a9e271e3a20ba8fe157abbfa057fcc6 100644 (file)
--- 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;
 }