From 0b597ef00ec7c7eebd836e2b1d5a266efcd60005 Mon Sep 17 00:00:00 2001 From: Josh Bailey Date: Wed, 20 Jul 2011 20:49:11 -0700 Subject: bgpd: When advertising a multipath route, the attribute set to be advertised is based on the bestpath attribute set, but the following attributes are aggregated from the attribute sets of the multipath constituents: - AS_PATH - ORIGIN - COMMUNITIES - EXTENDED COMMUNITIES In addition the route is advertised with the NEXT_HOP set to the router's interface IP address, instead of the NEXT_HOP of the best path. This is to ensure that traffic will go to this router so it can be fanned out via the multipath route. * bgpd/ecommunity.c * ecommunity_uniq_sort(): Make this function externally accessible * bgpd/ecommunity.h * Add external declaration for ecommunity_uniq_sort() * bgpd/bgp_mpath.c * bgp_info_nexthop_cmp(): Replace calls to bgp_attr_extra_get() to avoid unwanted memory allocation * bgp_info_mpath_free(): Free aggregate attribute for multipath * bgp_info_mpath_attr(): Lookup aggregate attribute of a multipath route * bgp_info_mpath_attr_set(): Set aggregate attribute of a multipath route * bgp_info_mpath_aggregate_update(): Update the aggregate attribute of a multipath route * bgpd/bgp_mpath.h * bgp_info_mpath: Add pointer to hold aggregate attribute of a multipath * Add external declarations for new functions * bgpd/bgp_route.c * bgp_announce_check(): Use aggregate attribute when announcing multipath route * bgp_announce_check_rsclient(): Use aggregate attribute when announcing multipath route * bgp_best_selection(): After updating multipath set, update the multipath aggregate attribute --- bgpd/bgp_ecommunity.c | 2 +- bgpd/bgp_ecommunity.h | 1 + bgpd/bgp_mpath.c | 193 +++++++++++++++++++++++++++++++++++++++++++++++++- bgpd/bgp_mpath.h | 6 ++ bgpd/bgp_route.c | 33 +++++---- 5 files changed, 218 insertions(+), 17 deletions(-) diff --git a/bgpd/bgp_ecommunity.c b/bgpd/bgp_ecommunity.c index 8d5fa741..244ffd16 100644 --- a/bgpd/bgp_ecommunity.c +++ b/bgpd/bgp_ecommunity.c @@ -98,7 +98,7 @@ ecommunity_add_val (struct ecommunity *ecom, struct ecommunity_val *eval) /* This function takes pointer to Extended Communites strucutre then create a new Extended Communities structure by uniq and sort each Extended Communities value. */ -static struct ecommunity * +struct ecommunity * ecommunity_uniq_sort (struct ecommunity *ecom) { int i; diff --git a/bgpd/bgp_ecommunity.h b/bgpd/bgp_ecommunity.h index 942fdc73..1a225270 100644 --- a/bgpd/bgp_ecommunity.h +++ b/bgpd/bgp_ecommunity.h @@ -71,6 +71,7 @@ extern void ecommunity_free (struct ecommunity *); extern struct ecommunity *ecommunity_parse (u_int8_t *, u_short); extern struct ecommunity *ecommunity_dup (struct ecommunity *); extern struct ecommunity *ecommunity_merge (struct ecommunity *, struct ecommunity *); +extern struct ecommunity *ecommunity_uniq_sort (struct ecommunity *); extern struct ecommunity *ecommunity_intern (struct ecommunity *); extern int ecommunity_cmp (const void *, const void *); extern void ecommunity_unintern (struct ecommunity *); diff --git a/bgpd/bgp_mpath.c b/bgpd/bgp_mpath.c index 7944c55f..44823c4b 100644 --- a/bgpd/bgp_mpath.c +++ b/bgpd/bgp_mpath.c @@ -34,6 +34,9 @@ #include "bgpd/bgp_route.h" #include "bgpd/bgp_attr.h" #include "bgpd/bgp_debug.h" +#include "bgpd/bgp_aspath.h" +#include "bgpd/bgp_community.h" +#include "bgpd/bgp_ecommunity.h" #include "bgpd/bgp_mpath.h" /* @@ -103,8 +106,8 @@ bgp_info_nexthop_cmp (struct bgp_info *bi1, struct bgp_info *bi2) struct attr_extra *ae1, *ae2; int compare; - ae1 = bgp_attr_extra_get (bi1->attr); - ae2 = bgp_attr_extra_get (bi2->attr); + ae1 = bi1->attr->extra; + ae2 = bi2->attr->extra; compare = IPV4_ADDR_CMP (&bi1->attr->nexthop, &bi2->attr->nexthop); @@ -226,6 +229,8 @@ bgp_info_mpath_free (struct bgp_info_mpath **mpath) { if (mpath && *mpath) { + if ((*mpath)->mp_attr) + bgp_attr_unintern ((*mpath)->mp_attr); XFREE (MTYPE_BGP_MPATH_INFO, *mpath); *mpath = NULL; } @@ -350,6 +355,37 @@ bgp_info_mpath_count_set (struct bgp_info *binfo, u_int32_t count) mpath->mp_count = count; } +/* + * bgp_info_mpath_attr + * + * Given bestpath bgp_info, return aggregated attribute set used + * for advertising the multipath route + */ +struct attr * +bgp_info_mpath_attr (struct bgp_info *binfo) +{ + if (!binfo->mpath) + return NULL; + return binfo->mpath->mp_attr; +} + +/* + * bgp_info_mpath_attr_set + * + * Sets the aggregated attribute into bestpath's mpath element + */ +static void +bgp_info_mpath_attr_set (struct bgp_info *binfo, struct attr *attr) +{ + struct bgp_info_mpath *mpath; + if (!attr && !binfo->mpath) + return; + mpath = bgp_info_mpath_get (binfo); + if (!mpath) + return; + mpath->mp_attr = attr; +} + /* * bgp_info_mpath_update * @@ -538,3 +574,156 @@ bgp_mp_dmed_deselect (struct bgp_info *dmed_best) UNSET_FLAG (dmed_best->flags, BGP_INFO_MULTIPATH_CHG); assert (bgp_info_mpath_first (dmed_best) == 0); } + +/* + * bgp_info_mpath_aggregate_update + * + * Set the multipath aggregate attribute. We need to see if the + * aggregate has changed and then set the ATTR_CHANGED flag on the + * bestpath info so that a peer update will be generated. The + * change is detected by generating the current attribute, + * interning it, and then comparing the interned pointer with the + * current value. We can skip this generate/compare step if there + * is no change in multipath selection and no attribute change in + * any multipath. + */ +void +bgp_info_mpath_aggregate_update (struct bgp_info *new_best, + struct bgp_info *old_best) +{ + struct bgp_info *mpinfo; + struct aspath *aspath; + struct aspath *asmerge; + struct attr *new_attr, *old_attr; + u_char origin, attr_chg; + struct community *community, *commerge; + struct ecommunity *ecomm, *ecommerge; + struct attr_extra *ae; + struct attr attr = { 0 }; + + if (old_best && (old_best != new_best) && + (old_attr = bgp_info_mpath_attr (old_best))) + { + bgp_attr_unintern (old_attr); + bgp_info_mpath_attr_set (old_best, NULL); + } + + if (!new_best) + return; + + if (!bgp_info_mpath_count (new_best)) + { + if ((new_attr = bgp_info_mpath_attr (new_best))) + { + bgp_attr_unintern (new_attr); + bgp_info_mpath_attr_set (new_best, NULL); + SET_FLAG (new_best->flags, BGP_INFO_ATTR_CHANGED); + } + return; + } + + /* + * Bail out here if the following is true: + * - MULTIPATH_CHG bit is not set on new_best, and + * - ATTR_CHANGED bit is not set on new_best or any of the multipaths + */ + attr_chg = 0; + if (CHECK_FLAG (new_best->flags, BGP_INFO_ATTR_CHANGED)) + attr_chg = 1; + else + for (mpinfo = bgp_info_mpath_first (new_best); mpinfo; + mpinfo = bgp_info_mpath_next (mpinfo)) + { + if (CHECK_FLAG (mpinfo->flags, BGP_INFO_ATTR_CHANGED)) + { + attr_chg = 1; + break; + } + } + if (!CHECK_FLAG (new_best->flags, BGP_INFO_MULTIPATH_CHG) && !attr_chg) + { + assert (bgp_info_mpath_attr (new_best)); + return; + } + + bgp_attr_dup (&attr, new_best->attr); + + /* aggregate attribute from multipath constituents */ + aspath = aspath_dup (attr.aspath); + origin = attr.origin; + community = attr.community ? community_dup (attr.community) : NULL; + ae = attr.extra; + ecomm = (ae && ae->ecommunity) ? ecommunity_dup (ae->ecommunity) : NULL; + + for (mpinfo = bgp_info_mpath_first (new_best); mpinfo; + mpinfo = bgp_info_mpath_next (mpinfo)) + { + asmerge = aspath_aggregate (aspath, mpinfo->attr->aspath); + aspath_free (aspath); + aspath = asmerge; + + if (origin < mpinfo->attr->origin) + origin = mpinfo->attr->origin; + + if (mpinfo->attr->community) + { + if (community) + { + commerge = community_merge (community, mpinfo->attr->community); + community = community_uniq_sort (commerge); + community_free (commerge); + } + else + community = community_dup (mpinfo->attr->community); + } + + ae = mpinfo->attr->extra; + if (ae && ae->ecommunity) + { + if (ecomm) + { + ecommerge = ecommunity_merge (ecomm, ae->ecommunity); + ecomm = ecommunity_uniq_sort (ecommerge); + ecommunity_free (ecommerge); + } + else + ecomm = ecommunity_dup (ae->ecommunity); + } + } + + attr.aspath = aspath; + attr.origin = origin; + if (community) + { + attr.community = community; + attr.flag |= ATTR_FLAG_BIT (BGP_ATTR_COMMUNITIES); + } + if (ecomm) + { + ae = bgp_attr_extra_get (&attr); + ae->ecommunity = ecomm; + attr.flag |= ATTR_FLAG_BIT (BGP_ATTR_EXT_COMMUNITIES); + } + + /* Zap multipath attr nexthop so we set nexthop to self */ + attr.nexthop.s_addr = 0; +#ifdef HAVE_IPV6 + if (attr.extra) + memset (&attr.extra->mp_nexthop_global, 0, sizeof (struct in6_addr)); +#endif /* HAVE_IPV6 */ + + /* TODO: should we set ATOMIC_AGGREGATE and AGGREGATOR? */ + + new_attr = bgp_attr_intern (&attr); + bgp_attr_extra_free (&attr); + + if (new_attr != bgp_info_mpath_attr (new_best)) + { + if ((old_attr = bgp_info_mpath_attr (new_best))) + bgp_attr_unintern (old_attr); + bgp_info_mpath_attr_set (new_best, new_attr); + SET_FLAG (new_best->flags, BGP_INFO_ATTR_CHANGED); + } + else + bgp_attr_unintern (new_attr); +} diff --git a/bgpd/bgp_mpath.h b/bgpd/bgp_mpath.h index 3712493e..37b9ac8b 100644 --- a/bgpd/bgp_mpath.h +++ b/bgpd/bgp_mpath.h @@ -43,6 +43,9 @@ struct bgp_info_mpath /* When attached to best path, the number of selected multipaths */ u_int32_t mp_count; + + /* Aggregated attribute for advertising multipath route */ + struct attr *mp_attr; }; /* Functions to support maximum-paths configuration */ @@ -59,6 +62,8 @@ extern void bgp_mp_dmed_deselect (struct bgp_info *); extern void bgp_info_mpath_update (struct bgp_node *, struct bgp_info *, struct bgp_info *, struct list *, struct bgp_maxpaths_cfg *); +extern void bgp_info_mpath_aggregate_update (struct bgp_info *, + struct bgp_info *); /* Unlink and free multipath information associated with a bgp_info */ extern void bgp_info_mpath_dequeue (struct bgp_info *); @@ -70,5 +75,6 @@ extern struct bgp_info *bgp_info_mpath_next (struct bgp_info *); /* Accessors for multipath information */ extern u_int32_t bgp_info_mpath_count (struct bgp_info *); +extern struct attr *bgp_info_mpath_attr (struct bgp_info *); #endif /* _QUAGGA_BGP_MPATH_H */ diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c index 5c4ab266..a4923f57 100644 --- a/bgpd/bgp_route.c +++ b/bgpd/bgp_route.c @@ -785,10 +785,12 @@ bgp_announce_check (struct bgp_info *ri, struct peer *peer, struct prefix *p, struct bgp *bgp; int transparent; int reflect; + struct attr *riattr; from = ri->peer; filter = &peer->filter[afi][safi]; bgp = peer->bgp; + riattr = bgp_info_mpath_count (ri) ? bgp_info_mpath_attr (ri) : ri->attr; if (DISABLE_BGP_ANNOUNCE) return 0; @@ -803,11 +805,11 @@ bgp_announce_check (struct bgp_info *ri, struct peer *peer, struct prefix *p, /* If peer's id and route's nexthop are same. draft-ietf-idr-bgp4-23 5.1.3 */ if (p->family == AF_INET - && IPV4_ADDR_SAME(&peer->remote_id, &ri->attr->nexthop)) + && IPV4_ADDR_SAME(&peer->remote_id, &riattr->nexthop)) return 0; #ifdef HAVE_IPV6 if (p->family == AF_INET6 - && IPV6_ADDR_SAME(&peer->remote_id, &ri->attr->nexthop)) + && IPV6_ADDR_SAME(&peer->remote_id, &riattr->nexthop)) return 0; #endif @@ -835,14 +837,14 @@ bgp_announce_check (struct bgp_info *ri, struct peer *peer, struct prefix *p, transparent = 0; /* If community is not disabled check the no-export and local. */ - if (! transparent && bgp_community_filter (peer, ri->attr)) + if (! transparent && bgp_community_filter (peer, riattr)) return 0; /* If the attribute has originator-id and it is same as remote peer's id. */ - if (ri->attr->flag & ATTR_FLAG_BIT (BGP_ATTR_ORIGINATOR_ID)) + if (riattr->flag & ATTR_FLAG_BIT (BGP_ATTR_ORIGINATOR_ID)) { - if (IPV4_ADDR_SAME (&peer->remote_id, &ri->attr->extra->originator_id)) + if (IPV4_ADDR_SAME (&peer->remote_id, &riattr->extra->originator_id)) { if (BGP_DEBUG (filter, FILTER)) zlog (peer->log, LOG_DEBUG, @@ -865,7 +867,7 @@ bgp_announce_check (struct bgp_info *ri, struct peer *peer, struct prefix *p, } /* Output filter check. */ - if (bgp_output_filter (peer, p, ri->attr, afi, safi) == FILTER_DENY) + if (bgp_output_filter (peer, p, riattr, afi, safi) == FILTER_DENY) { if (BGP_DEBUG (filter, FILTER)) zlog (peer->log, LOG_DEBUG, @@ -878,7 +880,7 @@ bgp_announce_check (struct bgp_info *ri, struct peer *peer, struct prefix *p, #ifdef BGP_SEND_ASPATH_CHECK /* AS path loop check. */ - if (aspath_loop_check (ri->attr->aspath, peer->as)) + if (aspath_loop_check (riattr->aspath, peer->as)) { if (BGP_DEBUG (filter, FILTER)) zlog (peer->log, LOG_DEBUG, @@ -891,7 +893,7 @@ bgp_announce_check (struct bgp_info *ri, struct peer *peer, struct prefix *p, /* If we're a CONFED we need to loop check the CONFED ID too */ if (CHECK_FLAG(bgp->config, BGP_CONFIG_CONFEDERATION)) { - if (aspath_loop_check(ri->attr->aspath, bgp->confed_id)) + if (aspath_loop_check(riattr->aspath, bgp->confed_id)) { if (BGP_DEBUG (filter, FILTER)) zlog (peer->log, LOG_DEBUG, @@ -932,7 +934,7 @@ bgp_announce_check (struct bgp_info *ri, struct peer *peer, struct prefix *p, } /* For modify attribute, copy it to temporary structure. */ - bgp_attr_dup (attr, ri->attr); + bgp_attr_dup (attr, riattr); /* If local-preference is not set. */ if ((peer_sort (peer) == BGP_PEER_IBGP @@ -1091,10 +1093,12 @@ bgp_announce_check_rsclient (struct bgp_info *ri, struct peer *rsclient, struct bgp_info info; struct peer *from; struct bgp *bgp; + struct attr *riattr; from = ri->peer; filter = &rsclient->filter[afi][safi]; bgp = rsclient->bgp; + riattr = bgp_info_mpath_count (ri) ? bgp_info_mpath_attr (ri) : ri->attr; if (DISABLE_BGP_ANNOUNCE) return 0; @@ -1122,10 +1126,10 @@ bgp_announce_check_rsclient (struct bgp_info *ri, struct peer *rsclient, /* If the attribute has originator-id and it is same as remote peer's id. */ - if (ri->attr->flag & ATTR_FLAG_BIT (BGP_ATTR_ORIGINATOR_ID)) + if (riattr->flag & ATTR_FLAG_BIT (BGP_ATTR_ORIGINATOR_ID)) { if (IPV4_ADDR_SAME (&rsclient->remote_id, - &ri->attr->extra->originator_id)) + &riattr->extra->originator_id)) { if (BGP_DEBUG (filter, FILTER)) zlog (rsclient->log, LOG_DEBUG, @@ -1148,7 +1152,7 @@ bgp_announce_check_rsclient (struct bgp_info *ri, struct peer *rsclient, } /* Output filter check. */ - if (bgp_output_filter (rsclient, p, ri->attr, afi, safi) == FILTER_DENY) + if (bgp_output_filter (rsclient, p, riattr, afi, safi) == FILTER_DENY) { if (BGP_DEBUG (filter, FILTER)) zlog (rsclient->log, LOG_DEBUG, @@ -1161,7 +1165,7 @@ bgp_announce_check_rsclient (struct bgp_info *ri, struct peer *rsclient, #ifdef BGP_SEND_ASPATH_CHECK /* AS path loop check. */ - if (aspath_loop_check (ri->attr->aspath, rsclient->as)) + if (aspath_loop_check (riattr->aspath, rsclient->as)) { if (BGP_DEBUG (filter, FILTER)) zlog (rsclient->log, LOG_DEBUG, @@ -1172,7 +1176,7 @@ bgp_announce_check_rsclient (struct bgp_info *ri, struct peer *rsclient, #endif /* BGP_SEND_ASPATH_CHECK */ /* For modify attribute, copy it to temporary structure. */ - bgp_attr_dup (attr, ri->attr); + bgp_attr_dup (attr, riattr); /* next-hop-set */ if ((p->family == AF_INET && attr->nexthop.s_addr == 0) @@ -1410,6 +1414,7 @@ bgp_best_selection (struct bgp *bgp, struct bgp_node *rn, if (!bgp_flag_check (bgp, BGP_FLAG_DETERMINISTIC_MED)) bgp_info_mpath_update (rn, new_select, old_select, &mp_list, mpath_cfg); + bgp_info_mpath_aggregate_update (new_select, old_select); bgp_mp_list_clear (&mp_list); result->old = old_select; -- cgit v1.2.1