/* BGP Nexthop tracking * Copyright (C) 2013 Cumulus Networks, Inc. * * This file is part of GNU Zebra. * * GNU Zebra is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2, or (at your option) any * later version. * * GNU Zebra is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; see the file COPYING; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include #include "command.h" #include "thread.h" #include "prefix.h" #include "zclient.h" #include "stream.h" #include "network.h" #include "log.h" #include "memory.h" #include "nexthop.h" #include "vrf.h" #include "filter.h" #include "bgpd/bgpd.h" #include "bgpd/bgp_table.h" #include "bgpd/bgp_route.h" #include "bgpd/bgp_attr.h" #include "bgpd/bgp_nexthop.h" #include "bgpd/bgp_debug.h" #include "bgpd/bgp_errors.h" #include "bgpd/bgp_nht.h" #include "bgpd/bgp_fsm.h" #include "bgpd/bgp_zebra.h" #include "bgpd/bgp_flowspec_util.h" #include "bgpd/bgp_evpn.h" #include "bgpd/bgp_rd.h" extern struct zclient *zclient; static void register_zebra_rnh(struct bgp_nexthop_cache *bnc, int is_bgp_static_route); static void unregister_zebra_rnh(struct bgp_nexthop_cache *bnc, int is_bgp_static_route); static void evaluate_paths(struct bgp_nexthop_cache *bnc); static int make_prefix(int afi, struct bgp_path_info *pi, struct prefix *p); static int bgp_isvalid_nexthop(struct bgp_nexthop_cache *bnc) { return (bgp_zebra_num_connects() == 0 || (bnc && CHECK_FLAG(bnc->flags, BGP_NEXTHOP_VALID))); } static int bgp_isvalid_labeled_nexthop(struct bgp_nexthop_cache *bnc) { return (bgp_zebra_num_connects() == 0 || (bnc && CHECK_FLAG(bnc->flags, BGP_NEXTHOP_LABELED_VALID))); } static void bgp_unlink_nexthop_check(struct bgp_nexthop_cache *bnc) { if (LIST_EMPTY(&(bnc->paths)) && !bnc->nht_info) { if (BGP_DEBUG(nht, NHT)) { char buf[PREFIX2STR_BUFFER]; zlog_debug("bgp_unlink_nexthop: freeing bnc %s(%u)(%s)", bnc_str(bnc, buf, PREFIX2STR_BUFFER), bnc->srte_color, bnc->bgp->name_pretty); } /* only unregister if this is the last nh for this prefix*/ if (!bnc_existing_for_prefix(bnc)) unregister_zebra_rnh( bnc, CHECK_FLAG(bnc->flags, BGP_STATIC_ROUTE)); bnc_free(bnc); } } void bgp_unlink_nexthop(struct bgp_path_info *path) { struct bgp_nexthop_cache *bnc = path->nexthop; if (!bnc) return; path_nh_map(path, NULL, false); bgp_unlink_nexthop_check(bnc); } void bgp_unlink_nexthop_by_peer(struct peer *peer) { struct prefix p; struct bgp_nexthop_cache *bnc; afi_t afi = family2afi(peer->su.sa.sa_family); if (!sockunion2hostprefix(&peer->su, &p)) return; bnc = bnc_find(&peer->bgp->nexthop_cache_table[afi], &p, 0); if (!bnc) return; /* cleanup the peer reference */ bnc->nht_info = NULL; bgp_unlink_nexthop_check(bnc); } /* * A route and its nexthop might belong to different VRFs. Therefore, * we need both the bgp_route and bgp_nexthop pointers. */ int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop, afi_t afi, struct bgp_path_info *pi, struct peer *peer, int connected) { struct bgp_nexthop_cache_head *tree = NULL; struct bgp_nexthop_cache *bnc; struct prefix p; uint32_t srte_color = 0; int is_bgp_static_route = 0; if (pi) { is_bgp_static_route = ((pi->type == ZEBRA_ROUTE_BGP) && (pi->sub_type == BGP_ROUTE_STATIC)) ? 1 : 0; /* Since Extended Next-hop Encoding (RFC5549) support, we want to derive address-family from the next-hop. */ if (!is_bgp_static_route) afi = BGP_ATTR_NEXTHOP_AFI_IP6(pi->attr) ? AFI_IP6 : AFI_IP; /* Validation for the ipv4 mapped ipv6 nexthop. */ if (IS_MAPPED_IPV6(&pi->attr->mp_nexthop_global)) { afi = AFI_IP; } /* This will return true if the global IPv6 NH is a link local * addr */ if (make_prefix(afi, pi, &p) < 0) return 1; srte_color = pi->attr->srte_color; } else if (peer) { if (!sockunion2hostprefix(&peer->su, &p)) { if (BGP_DEBUG(nht, NHT)) { zlog_debug( "%s: Attempting to register with unknown AFI %d (not %d or %d)", __func__, afi, AFI_IP, AFI_IP6); } return 0; } } else return 0; if (is_bgp_static_route) tree = &bgp_nexthop->import_check_table[afi]; else tree = &bgp_nexthop->nexthop_cache_table[afi]; bnc = bnc_find(tree, &p, srte_color); if (!bnc) { bnc = bnc_new(tree, &p, srte_color); bnc->bgp = bgp_nexthop; if (BGP_DEBUG(nht, NHT)) { char buf[PREFIX2STR_BUFFER]; zlog_debug("Allocated bnc %s(%u)(%s) peer %p", bnc_str(bnc, buf, PREFIX2STR_BUFFER), bnc->srte_color, bnc->bgp->name_pretty, peer); } } if (is_bgp_static_route) { SET_FLAG(bnc->flags, BGP_STATIC_ROUTE); /* If we're toggling the type, re-register */ if ((CHECK_FLAG(bgp_route->flags, BGP_FLAG_IMPORT_CHECK)) && !CHECK_FLAG(bnc->flags, BGP_STATIC_ROUTE_EXACT_MATCH)) { SET_FLAG(bnc->flags, BGP_STATIC_ROUTE_EXACT_MATCH); UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED); UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID); } else if ((!CHECK_FLAG(bgp_route->flags, BGP_FLAG_IMPORT_CHECK)) && CHECK_FLAG(bnc->flags, BGP_STATIC_ROUTE_EXACT_MATCH)) { UNSET_FLAG(bnc->flags, BGP_STATIC_ROUTE_EXACT_MATCH); UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED); UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID); } } /* When nexthop is already known, but now requires 'connected' * resolution, * re-register it. The reverse scenario where the nexthop currently * requires * 'connected' resolution does not need a re-register (i.e., we treat * 'connected-required' as an override) except in the scenario where * this * is actually a case of tracking a peer for connectivity (e.g., after * disable connected-check). * NOTE: We don't track the number of paths separately for 'connected- * required' vs 'connected-not-required' as this change is not a common * scenario. */ else if (connected && !CHECK_FLAG(bnc->flags, BGP_NEXTHOP_CONNECTED)) { SET_FLAG(bnc->flags, BGP_NEXTHOP_CONNECTED); UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED); UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID); } else if (peer && !connected && CHECK_FLAG(bnc->flags, BGP_NEXTHOP_CONNECTED)) { UNSET_FLAG(bnc->flags, BGP_NEXTHOP_CONNECTED); UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED); UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID); } if (bgp_route->inst_type == BGP_INSTANCE_TYPE_VIEW) { SET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED); SET_FLAG(bnc->flags, BGP_NEXTHOP_VALID); } else if (!CHECK_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED) && !is_default_host_route(&bnc->prefix)) register_zebra_rnh(bnc, is_bgp_static_route); if (pi && pi->nexthop != bnc) { /* Unlink from existing nexthop cache, if any. This will also * free * the nexthop cache entry, if appropriate. */ bgp_unlink_nexthop(pi); /* updates NHT pi list reference */ path_nh_map(pi, bnc, true); if (CHECK_FLAG(bnc->flags, BGP_NEXTHOP_VALID) && bnc->metric) (bgp_path_info_extra_get(pi))->igpmetric = bnc->metric; else if (pi->extra) pi->extra->igpmetric = 0; } else if (peer) bnc->nht_info = (void *)peer; /* NHT peer reference */ /* * We are cheating here. Views have no associated underlying * ability to detect nexthops. So when we have a view * just tell everyone the nexthop is valid */ if (bgp_route->inst_type == BGP_INSTANCE_TYPE_VIEW) return 1; else return (bgp_isvalid_nexthop(bnc)); } void bgp_delete_connected_nexthop(afi_t afi, struct peer *peer) { struct bgp_nexthop_cache *bnc; struct prefix p; if (!peer) return; if (!sockunion2hostprefix(&peer->su, &p)) return; bnc = bnc_find(&peer->bgp->nexthop_cache_table[family2afi(p.family)], &p, 0); if (!bnc) { if (BGP_DEBUG(nht, NHT)) zlog_debug( "Cannot find connected NHT node for peer %s(%s)", peer->host, peer->bgp->name_pretty); return; } if (bnc->nht_info != peer) { if (BGP_DEBUG(nht, NHT)) zlog_debug( "Connected NHT %p node for peer %s(%s) points to %p", bnc, peer->host, bnc->bgp->name_pretty, bnc->nht_info); return; } bnc->nht_info = NULL; if (LIST_EMPTY(&(bnc->paths))) { if (BGP_DEBUG(nht, NHT)) zlog_debug( "Freeing connected NHT node %p for peer %s(%s)", bnc, peer->host, bnc->bgp->name_pretty); unregister_zebra_rnh(bnc, 0); bnc_free(bnc); } } static void bgp_process_nexthop_update(struct bgp_nexthop_cache *bnc, struct zapi_route *nhr) { struct nexthop *nexthop; struct nexthop *oldnh; struct nexthop *nhlist_head = NULL; struct nexthop *nhlist_tail = NULL; int i; bnc->last_update = bgp_clock(); bnc->change_flags = 0; /* debug print the input */ if (BGP_DEBUG(nht, NHT)) { char buf[PREFIX2STR_BUFFER]; prefix2str(&nhr->prefix, buf, sizeof(buf)); zlog_debug( "%s(%u): Rcvd NH update %s(%u) - metric %d/%d #nhops %d/%d flags 0x%x", bnc->bgp->name_pretty, bnc->bgp->vrf_id, buf, bnc->srte_color, nhr->metric, bnc->metric, nhr->nexthop_num, bnc->nexthop_num, bnc->flags); } if (nhr->metric != bnc->metric) bnc->change_flags |= BGP_NEXTHOP_METRIC_CHANGED; if (nhr->nexthop_num != bnc->nexthop_num) bnc->change_flags |= BGP_NEXTHOP_CHANGED; if (nhr->nexthop_num) { struct peer *peer = bnc->nht_info; /* notify bgp fsm if nbr ip goes from invalid->valid */ if (!bnc->nexthop_num) UNSET_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED); bnc->flags |= BGP_NEXTHOP_VALID; bnc->metric = nhr->metric; bnc->nexthop_num = nhr->nexthop_num; bnc->flags &= ~BGP_NEXTHOP_LABELED_VALID; /* check below */ for (i = 0; i < nhr->nexthop_num; i++) { int num_labels = 0; nexthop = nexthop_from_zapi_nexthop(&nhr->nexthops[i]); /* * Turn on RA for the v6 nexthops * we receive from bgp. This is to allow us * to work with v4 routing over v6 nexthops */ if (peer && !peer->ifp && CHECK_FLAG(peer->flags, PEER_FLAG_CAPABILITY_ENHE) && nhr->prefix.family == AF_INET6 && nexthop->type != NEXTHOP_TYPE_BLACKHOLE) { struct interface *ifp; ifp = if_lookup_by_index(nexthop->ifindex, nexthop->vrf_id); if (ifp) zclient_send_interface_radv_req( zclient, nexthop->vrf_id, ifp, true, BGP_UNNUM_DEFAULT_RA_INTERVAL); } /* There is at least one label-switched path */ if (nexthop->nh_label && nexthop->nh_label->num_labels) { bnc->flags |= BGP_NEXTHOP_LABELED_VALID; num_labels = nexthop->nh_label->num_labels; } if (BGP_DEBUG(nht, NHT)) { char buf[NEXTHOP_STRLEN]; zlog_debug( " nhop via %s (%d labels)", nexthop2str(nexthop, buf, sizeof(buf)), num_labels); } if (nhlist_tail) { nhlist_tail->next = nexthop; nhlist_tail = nexthop; } else { nhlist_tail = nexthop; nhlist_head = nexthop; } /* No need to evaluate the nexthop if we have already * determined * that there has been a change. */ if (bnc->change_flags & BGP_NEXTHOP_CHANGED) continue; for (oldnh = bnc->nexthop; oldnh; oldnh = oldnh->next) if (nexthop_same(oldnh, nexthop)) break; if (!oldnh) bnc->change_flags |= BGP_NEXTHOP_CHANGED; } bnc_nexthop_free(bnc); bnc->nexthop = nhlist_head; } else { bnc->flags &= ~BGP_NEXTHOP_VALID; bnc->nexthop_num = nhr->nexthop_num; /* notify bgp fsm if nbr ip goes from valid->invalid */ UNSET_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED); bnc_nexthop_free(bnc); bnc->nexthop = NULL; } evaluate_paths(bnc); } void bgp_parse_nexthop_update(int command, vrf_id_t vrf_id) { struct bgp_nexthop_cache_head *tree = NULL; struct bgp_nexthop_cache *bnc; struct bgp *bgp; struct zapi_route nhr; afi_t afi; bgp = bgp_lookup_by_vrf_id(vrf_id); if (!bgp) { flog_err( EC_BGP_NH_UPD, "parse nexthop update: instance not found for vrf_id %u", vrf_id); return; } if (!zapi_nexthop_update_decode(zclient->ibuf, &nhr)) { zlog_err("%s[%s]: Failure to decode nexthop update", __PRETTY_FUNCTION__, bgp->name_pretty); return; } afi = family2afi(nhr.prefix.family); if (command == ZEBRA_NEXTHOP_UPDATE) tree = &bgp->nexthop_cache_table[afi]; else if (command == ZEBRA_IMPORT_CHECK_UPDATE) tree = &bgp->import_check_table[afi]; bnc = bnc_find(tree, &nhr.prefix, nhr.srte_color); if (!bnc) { if (BGP_DEBUG(nht, NHT)) { char buf[PREFIX2STR_BUFFER]; prefix2str(&nhr.prefix, buf, sizeof(buf)); zlog_debug( "parse nexthop update(%s(%u)(%s)): bnc info not found", buf, nhr.srte_color, bgp->name_pretty); } return; } bgp_process_nexthop_update(bnc, &nhr); /* * HACK: if any BGP route is dependant on an SR-policy that doesn't * exist, zebra will never send NH updates relative to that policy. In * that case, whenever we receive an update about a colorless NH, update * the corresponding colorful NHs that share the same endpoint but that * are inactive. This ugly hack should work around the problem at the * cost of a performance pernalty. Long term, what should be done is to * make zebra's RNH subsystem aware of SR-TE colors (like bgpd is), * which should provide a better infrastructure to solve this issue in * a more efficient and elegant way. */ if (nhr.srte_color == 0) { struct bgp_nexthop_cache *bnc_iter; frr_each (bgp_nexthop_cache, &bgp->nexthop_cache_table[afi], bnc_iter) { if (!prefix_same(&bnc->prefix, &bnc_iter->prefix) || bnc_iter->srte_color == 0 || CHECK_FLAG(bnc_iter->flags, BGP_NEXTHOP_VALID)) continue; bgp_process_nexthop_update(bnc_iter, &nhr); } } } /* * Cleanup nexthop registration and status information for BGP nexthops * pertaining to this VRF. This is invoked upon VRF deletion. */ void bgp_cleanup_nexthops(struct bgp *bgp) { for (afi_t afi = AFI_IP; afi < AFI_MAX; afi++) { struct bgp_nexthop_cache *bnc; frr_each (bgp_nexthop_cache, &bgp->nexthop_cache_table[afi], bnc) { /* Clear relevant flags. */ UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID); UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED); UNSET_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED); } } } /** * make_prefix - make a prefix structure from the path (essentially * path's node. */ static int make_prefix(int afi, struct bgp_path_info *pi, struct prefix *p) { int is_bgp_static = ((pi->type == ZEBRA_ROUTE_BGP) && (pi->sub_type == BGP_ROUTE_STATIC)) ? 1 : 0; struct bgp_dest *net = pi->net; const struct prefix *p_orig = bgp_dest_get_prefix(net); struct in_addr ipv4; if (p_orig->family == AF_FLOWSPEC) { if (!pi->peer) return -1; return bgp_flowspec_get_first_nh(pi->peer->bgp, pi, p, afi); } memset(p, 0, sizeof(struct prefix)); switch (afi) { case AFI_IP: p->family = AF_INET; if (is_bgp_static) { p->u.prefix4 = p_orig->u.prefix4; p->prefixlen = p_orig->prefixlen; } else { if (IS_MAPPED_IPV6(&pi->attr->mp_nexthop_global)) { ipv4_mapped_ipv6_to_ipv4( &pi->attr->mp_nexthop_global, &ipv4); p->u.prefix4 = ipv4; p->prefixlen = IPV4_MAX_BITLEN; } else { p->u.prefix4 = pi->attr->nexthop; p->prefixlen = IPV4_MAX_BITLEN; } } break; case AFI_IP6: p->family = AF_INET6; if (is_bgp_static) { p->u.prefix6 = p_orig->u.prefix6; p->prefixlen = p_orig->prefixlen; } else { /* If we receive MP_REACH nexthop with ::(LL) * or LL(LL), use LL address as nexthop cache. */ if (pi->attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL && (IN6_IS_ADDR_UNSPECIFIED( &pi->attr->mp_nexthop_global) || IN6_IS_ADDR_LINKLOCAL( &pi->attr->mp_nexthop_global))) p->u.prefix6 = pi->attr->mp_nexthop_local; else p->u.prefix6 = pi->attr->mp_nexthop_global; p->prefixlen = IPV6_MAX_BITLEN; } break; default: if (BGP_DEBUG(nht, NHT)) { zlog_debug( "%s: Attempting to make prefix with unknown AFI %d (not %d or %d)", __func__, afi, AFI_IP, AFI_IP6); } break; } return 0; } /** * sendmsg_zebra_rnh -- Format and send a nexthop register/Unregister * command to Zebra. * ARGUMENTS: * struct bgp_nexthop_cache *bnc -- the nexthop structure. * int command -- command to send to zebra * RETURNS: * void. */ static void sendmsg_zebra_rnh(struct bgp_nexthop_cache *bnc, int command) { bool exact_match = false; int ret; if (!zclient) return; /* Don't try to register if Zebra doesn't know of this instance. */ if (!IS_BGP_INST_KNOWN_TO_ZEBRA(bnc->bgp)) { if (BGP_DEBUG(zebra, ZEBRA)) zlog_debug( "%s: No zebra instance to talk to, not installing NHT entry", __func__); return; } if (!bgp_zebra_num_connects()) { if (BGP_DEBUG(zebra, ZEBRA)) zlog_debug( "%s: We have not connected yet, cannot send nexthops", __func__); } if ((command == ZEBRA_NEXTHOP_REGISTER || command == ZEBRA_IMPORT_ROUTE_REGISTER) && (CHECK_FLAG(bnc->flags, BGP_NEXTHOP_CONNECTED) || CHECK_FLAG(bnc->flags, BGP_STATIC_ROUTE_EXACT_MATCH))) exact_match = true; if (BGP_DEBUG(zebra, ZEBRA)) zlog_debug("%s: sending cmd %s for %pFX (vrf %s)", __func__, zserv_command_string(command), &bnc->prefix, bnc->bgp->name_pretty); ret = zclient_send_rnh(zclient, command, &bnc->prefix, exact_match, bnc->bgp->vrf_id); /* TBD: handle the failure */ if (ret < 0) flog_warn(EC_BGP_ZEBRA_SEND, "sendmsg_nexthop: zclient_send_message() failed"); if ((command == ZEBRA_NEXTHOP_REGISTER) || (command == ZEBRA_IMPORT_ROUTE_REGISTER)) SET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED); else if ((command == ZEBRA_NEXTHOP_UNREGISTER) || (command == ZEBRA_IMPORT_ROUTE_UNREGISTER)) UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED); return; } /** * register_zebra_rnh - register a NH/route with Zebra for notification * when the route or the route to the nexthop changes. * ARGUMENTS: * struct bgp_nexthop_cache *bnc * RETURNS: * void. */ static void register_zebra_rnh(struct bgp_nexthop_cache *bnc, int is_bgp_import_route) { /* Check if we have already registered */ if (bnc->flags & BGP_NEXTHOP_REGISTERED) return; if (is_bgp_import_route) sendmsg_zebra_rnh(bnc, ZEBRA_IMPORT_ROUTE_REGISTER); else sendmsg_zebra_rnh(bnc, ZEBRA_NEXTHOP_REGISTER); } /** * unregister_zebra_rnh -- Unregister the route/nexthop from Zebra. * ARGUMENTS: * struct bgp_nexthop_cache *bnc * RETURNS: * void. */ static void unregister_zebra_rnh(struct bgp_nexthop_cache *bnc, int is_bgp_import_route) { /* Check if we have already registered */ if (!CHECK_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED)) return; if (is_bgp_import_route) sendmsg_zebra_rnh(bnc, ZEBRA_IMPORT_ROUTE_UNREGISTER); else sendmsg_zebra_rnh(bnc, ZEBRA_NEXTHOP_UNREGISTER); } /** * evaluate_paths - Evaluate the paths/nets associated with a nexthop. * ARGUMENTS: * struct bgp_nexthop_cache *bnc -- the nexthop structure. * RETURNS: * void. */ static void evaluate_paths(struct bgp_nexthop_cache *bnc) { struct bgp_dest *dest; struct bgp_path_info *path; int afi; struct peer *peer = (struct peer *)bnc->nht_info; struct bgp_table *table; safi_t safi; struct bgp *bgp_path; const struct prefix *p; if (BGP_DEBUG(nht, NHT)) { char buf[PREFIX2STR_BUFFER]; bnc_str(bnc, buf, PREFIX2STR_BUFFER); zlog_debug( "NH update for %s(%u)(%s) - flags 0x%x chgflags 0x%x - evaluate paths", buf, bnc->srte_color, bnc->bgp->name_pretty, bnc->flags, bnc->change_flags); } LIST_FOREACH (path, &(bnc->paths), nh_thread) { if (!(path->type == ZEBRA_ROUTE_BGP && ((path->sub_type == BGP_ROUTE_NORMAL) || (path->sub_type == BGP_ROUTE_STATIC) || (path->sub_type == BGP_ROUTE_IMPORTED)))) continue; dest = path->net; assert(dest && bgp_dest_table(dest)); p = bgp_dest_get_prefix(dest); afi = family2afi(p->family); table = bgp_dest_table(dest); safi = table->safi; /* * handle routes from other VRFs (they can have a * nexthop in THIS VRF). bgp_path is the bgp instance * that owns the route referencing this nexthop. */ bgp_path = table->bgp; /* * Path becomes valid/invalid depending on whether the nexthop * reachable/unreachable. * * In case of unicast routes that were imported from vpn * and that have labels, they are valid only if there are * nexthops with labels */ bool bnc_is_valid_nexthop = false; bool path_valid = false; if (safi == SAFI_UNICAST && path->sub_type == BGP_ROUTE_IMPORTED && path->extra && path->extra->num_labels) { bnc_is_valid_nexthop = bgp_isvalid_labeled_nexthop(bnc) ? true : false; } else { if (bgp_update_martian_nexthop( bnc->bgp, afi, safi, path->type, path->sub_type, path->attr, dest)) { if (BGP_DEBUG(nht, NHT)) zlog_debug( "%s: prefix %pRN (vrf %s), ignoring path due to martian or self-next-hop", __func__, dest, bgp_path->name); } else bnc_is_valid_nexthop = bgp_isvalid_nexthop(bnc) ? true : false; } if (BGP_DEBUG(nht, NHT)) { char buf1[RD_ADDRSTRLEN]; if (dest->pdest) { prefix_rd2str((struct prefix_rd *)bgp_dest_get_prefix(dest->pdest), buf1, sizeof(buf1)); zlog_debug( "... eval path %d/%d %pRN RD %s %s flags 0x%x", afi, safi, dest, buf1, bgp_path->name_pretty, path->flags); } else zlog_debug( "... eval path %d/%d %pRN %s flags 0x%x", afi, safi, dest, bgp_path->name_pretty, path->flags); } /* Skip paths marked for removal or as history. */ if (CHECK_FLAG(path->flags, BGP_PATH_REMOVED) || CHECK_FLAG(path->flags, BGP_PATH_HISTORY)) continue; /* Copy the metric to the path. Will be used for bestpath * computation */ if (bgp_isvalid_nexthop(bnc) && bnc->metric) (bgp_path_info_extra_get(path))->igpmetric = bnc->metric; else if (path->extra) path->extra->igpmetric = 0; if (CHECK_FLAG(bnc->change_flags, BGP_NEXTHOP_METRIC_CHANGED) || CHECK_FLAG(bnc->change_flags, BGP_NEXTHOP_CHANGED) || path->attr->srte_color != 0) SET_FLAG(path->flags, BGP_PATH_IGP_CHANGED); path_valid = !!CHECK_FLAG(path->flags, BGP_PATH_VALID); if (path_valid != bnc_is_valid_nexthop) { if (path_valid) { /* No longer valid, clear flag; also for EVPN * routes, unimport from VRFs if needed. */ bgp_aggregate_decrement(bgp_path, p, path, afi, safi); bgp_path_info_unset_flag(dest, path, BGP_PATH_VALID); if (safi == SAFI_EVPN && bgp_evpn_is_prefix_nht_supported(bgp_dest_get_prefix(dest))) bgp_evpn_unimport_route(bgp_path, afi, safi, bgp_dest_get_prefix(dest), path); } else { /* Path becomes valid, set flag; also for EVPN * routes, import from VRFs if needed. */ bgp_path_info_set_flag(dest, path, BGP_PATH_VALID); bgp_aggregate_increment(bgp_path, p, path, afi, safi); if (safi == SAFI_EVPN && bgp_evpn_is_prefix_nht_supported(bgp_dest_get_prefix(dest))) bgp_evpn_import_route(bgp_path, afi, safi, bgp_dest_get_prefix(dest), path); } } bgp_process(bgp_path, dest, afi, safi); } if (peer) { int valid_nexthops = bgp_isvalid_nexthop(bnc); if (valid_nexthops) peer->last_reset = PEER_DOWN_WAITING_OPEN; else peer->last_reset = PEER_DOWN_WAITING_NHT; if (!CHECK_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED)) { if (BGP_DEBUG(nht, NHT)) zlog_debug( "%s: Updating peer (%s(%s)) status with NHT", __func__, peer->host, peer->bgp->name_pretty); bgp_fsm_nht_update(peer, !!valid_nexthops); SET_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED); } } RESET_FLAG(bnc->change_flags); } /** * path_nh_map - make or break path-to-nexthop association. * ARGUMENTS: * path - pointer to the path structure * bnc - pointer to the nexthop structure * make - if set, make the association. if unset, just break the existing * association. */ void path_nh_map(struct bgp_path_info *path, struct bgp_nexthop_cache *bnc, bool make) { if (path->nexthop) { LIST_REMOVE(path, nh_thread); path->nexthop->path_count--; path->nexthop = NULL; } if (make) { LIST_INSERT_HEAD(&(bnc->paths), path, nh_thread); path->nexthop = bnc; path->nexthop->path_count++; } } /* * This function is called to register nexthops to zebra * as that we may have tried to install the nexthops * before we actually have a zebra connection */ void bgp_nht_register_nexthops(struct bgp *bgp) { for (afi_t afi = AFI_IP; afi < AFI_MAX; afi++) { struct bgp_nexthop_cache *bnc; frr_each (bgp_nexthop_cache, &bgp->nexthop_cache_table[afi], bnc) { register_zebra_rnh(bnc, 0); } } } void bgp_nht_reg_enhe_cap_intfs(struct peer *peer) { struct bgp *bgp; struct bgp_nexthop_cache *bnc; struct nexthop *nhop; struct interface *ifp; struct prefix p; if (peer->ifp) return; bgp = peer->bgp; if (!sockunion2hostprefix(&peer->su, &p)) { zlog_warn("%s: Unable to convert sockunion to prefix for %s", __func__, peer->host); return; } if (p.family != AF_INET6) return; bnc = bnc_find(&bgp->nexthop_cache_table[AFI_IP6], &p, 0); if (!bnc) return; if (peer != bnc->nht_info) return; for (nhop = bnc->nexthop; nhop; nhop = nhop->next) { ifp = if_lookup_by_index(nhop->ifindex, nhop->vrf_id); if (!ifp) continue; zclient_send_interface_radv_req(zclient, nhop->vrf_id, ifp, true, BGP_UNNUM_DEFAULT_RA_INTERVAL); } } void bgp_nht_dereg_enhe_cap_intfs(struct peer *peer) { struct bgp *bgp; struct bgp_nexthop_cache *bnc; struct nexthop *nhop; struct interface *ifp; struct prefix p; if (peer->ifp) return; bgp = peer->bgp; if (!sockunion2hostprefix(&peer->su, &p)) { zlog_warn("%s: Unable to convert sockunion to prefix for %s", __func__, peer->host); return; } if (p.family != AF_INET6) return; bnc = bnc_find(&bgp->nexthop_cache_table[AFI_IP6], &p, 0); if (!bnc) return; if (peer != bnc->nht_info) return; for (nhop = bnc->nexthop; nhop; nhop = nhop->next) { ifp = if_lookup_by_index(nhop->ifindex, nhop->vrf_id); if (!ifp) continue; zclient_send_interface_radv_req(zclient, nhop->vrf_id, ifp, 0, 0); } }