/* $OpenBSD: rde_update.c,v 1.60 2007/05/31 04:27:00 claudio Exp $ */ /* * Copyright (c) 2004 Claudio Jeker * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include #include #include "bgpd.h" #include "rde.h" in_addr_t up_get_nexthop(struct rde_peer *, struct rde_aspath *); int up_generate_mp_reach(struct rde_peer *, struct update_attr *, struct rde_aspath *, sa_family_t); int up_generate_attr(struct rde_peer *, struct update_attr *, struct rde_aspath *, sa_family_t); /* update stuff. */ struct update_prefix { TAILQ_ENTRY(update_prefix) prefix_l; RB_ENTRY(update_prefix) entry; struct uplist_prefix *prefix_h; struct bgpd_addr prefix; int prefixlen; }; struct update_attr { TAILQ_ENTRY(update_attr) attr_l; RB_ENTRY(update_attr) entry; struct uplist_prefix prefix_h; u_char *attr; u_char *mpattr; u_int32_t attr_hash; u_int16_t attr_len; u_int16_t mpattr_len; }; void up_clear(struct uplist_attr *, struct uplist_prefix *); int up_prefix_cmp(struct update_prefix *, struct update_prefix *); int up_attr_cmp(struct update_attr *, struct update_attr *); int up_add(struct rde_peer *, struct update_prefix *, struct update_attr *); RB_PROTOTYPE(uptree_prefix, update_prefix, entry, up_prefix_cmp) RB_GENERATE(uptree_prefix, update_prefix, entry, up_prefix_cmp) RB_PROTOTYPE(uptree_attr, update_attr, entry, up_attr_cmp) RB_GENERATE(uptree_attr, update_attr, entry, up_attr_cmp) void up_init(struct rde_peer *peer) { TAILQ_INIT(&peer->updates); TAILQ_INIT(&peer->withdraws); TAILQ_INIT(&peer->updates6); TAILQ_INIT(&peer->withdraws6); RB_INIT(&peer->up_prefix); RB_INIT(&peer->up_attrs); peer->up_pcnt = 0; peer->up_acnt = 0; peer->up_nlricnt = 0; peer->up_wcnt = 0; } void up_clear(struct uplist_attr *updates, struct uplist_prefix *withdraws) { struct update_attr *ua; struct update_prefix *up; while ((ua = TAILQ_FIRST(updates)) != NULL) { TAILQ_REMOVE(updates, ua, attr_l); while ((up = TAILQ_FIRST(&ua->prefix_h)) != NULL) { TAILQ_REMOVE(&ua->prefix_h, up, prefix_l); free(up); } free(ua->attr); free(ua->mpattr); free(ua); } while ((up = TAILQ_FIRST(withdraws)) != NULL) { TAILQ_REMOVE(withdraws, up, prefix_l); free(up); } } void up_down(struct rde_peer *peer) { up_clear(&peer->updates, &peer->withdraws); up_clear(&peer->updates6, &peer->withdraws6); RB_INIT(&peer->up_prefix); RB_INIT(&peer->up_attrs); peer->up_pcnt = 0; peer->up_acnt = 0; peer->up_nlricnt = 0; peer->up_wcnt = 0; } int up_prefix_cmp(struct update_prefix *a, struct update_prefix *b) { int i; if (a->prefix.af < b->prefix.af) return (-1); if (a->prefix.af > b->prefix.af) return (1); switch (a->prefix.af) { case AF_INET: if (ntohl(a->prefix.v4.s_addr) < ntohl(b->prefix.v4.s_addr)) return (-1); if (ntohl(a->prefix.v4.s_addr) > ntohl(b->prefix.v4.s_addr)) return (1); break; case AF_INET6: i = memcmp(&a->prefix.v6, &b->prefix.v6, sizeof(struct in6_addr)); if (i > 0) return (1); if (i < 0) return (-1); break; default: fatalx("pt_prefix_cmp: unknown af"); } if (a->prefixlen < b->prefixlen) return (-1); if (a->prefixlen > b->prefixlen) return (1); return (0); } int up_attr_cmp(struct update_attr *a, struct update_attr *b) { int r; if ((r = a->attr_hash - b->attr_hash) != 0) return (r); if ((r = a->attr_len - b->attr_len) != 0) return (r); if ((r = a->mpattr_len - b->mpattr_len) != 0) return (r); if ((r = memcmp(a->mpattr, b->mpattr, a->mpattr_len)) != 0) return (r); return (memcmp(a->attr, b->attr, a->attr_len)); } int up_add(struct rde_peer *peer, struct update_prefix *p, struct update_attr *a) { struct update_attr *na = NULL; struct update_prefix *np; struct uplist_attr *upl = NULL; struct uplist_prefix *wdl = NULL; switch (p->prefix.af) { case AF_INET: upl = &peer->updates; wdl = &peer->withdraws; break; case AF_INET6: upl = &peer->updates6; wdl = &peer->withdraws6; break; default: fatalx("up_add: unknown AF"); } /* 1. search for attr */ if (a != NULL && (na = RB_FIND(uptree_attr, &peer->up_attrs, a)) == NULL) { /* 1.1 if not found -> add */ TAILQ_INIT(&a->prefix_h); if (RB_INSERT(uptree_attr, &peer->up_attrs, a) != NULL) { log_warnx("uptree_attr insert failed"); /* cleanup */ free(a->attr); free(a->mpattr); free(a); free(p); return (-1); } TAILQ_INSERT_TAIL(upl, a, attr_l); peer->up_acnt++; } else { /* 1.2 if found -> use that, free a */ if (a != NULL) { free(a->attr); free(a->mpattr); free(a); a = na; /* move to end of update queue */ TAILQ_REMOVE(upl, a, attr_l); TAILQ_INSERT_TAIL(upl, a, attr_l); } } /* 2. search for prefix */ if ((np = RB_FIND(uptree_prefix, &peer->up_prefix, p)) == NULL) { /* 2.1 if not found -> add */ if (RB_INSERT(uptree_prefix, &peer->up_prefix, p) != NULL) { log_warnx("uptree_prefix insert failed"); /* * cleanup. But do not free a because it is already * linked or NULL. up_dump_attrnlri() will remove and * free the empty attribute later. */ free(p); return (-1); } peer->up_pcnt++; } else { /* 2.2 if found -> use that and free p */ TAILQ_REMOVE(np->prefix_h, np, prefix_l); free(p); p = np; if (p->prefix_h == wdl) peer->up_wcnt--; else peer->up_nlricnt--; } /* 3. link prefix to attr */ if (a == NULL) { TAILQ_INSERT_TAIL(wdl, p, prefix_l); p->prefix_h = wdl; peer->up_wcnt++; } else { TAILQ_INSERT_TAIL(&a->prefix_h, p, prefix_l); p->prefix_h = &a->prefix_h; peer->up_nlricnt++; } return (0); } int up_test_update(struct rde_peer *peer, struct prefix *p) { struct bgpd_addr addr; struct attr *attr; if (peer->state != PEER_UP) return (-1); if (p == NULL) /* no prefix available */ return (0); if (peer == p->aspath->peer) /* Do not send routes back to sender */ return (0); pt_getaddr(p->prefix, &addr); switch (addr.af) { case AF_INET: if (peer->capa_announced.mp_v4 == SAFI_NONE && peer->capa_received.mp_v6 != SAFI_NONE) return (-1); break; case AF_INET6: if (peer->capa_announced.mp_v6 == SAFI_NONE) return (-1); break; } if (p->aspath->peer->conf.ebgp == 0 && peer->conf.ebgp == 0) { /* * route reflector redistribution rules: * 1. if announce is set -> announce * 2. old non-client, new non-client -> no * 3. old client, new non-client -> yes * 4. old non-client, new client -> yes * 5. old client, new client -> yes */ if (p->aspath->peer->conf.reflector_client == 0 && peer->conf.reflector_client == 0 && (p->aspath->flags & F_PREFIX_ANNOUNCED) == 0) /* Do not redistribute updates to ibgp peers */ return (0); } /* announce type handling */ switch (peer->conf.announce_type) { case ANNOUNCE_UNDEF: case ANNOUNCE_NONE: case ANNOUNCE_DEFAULT_ROUTE: /* * no need to withdraw old prefix as this will be * filtered out as well. */ return (-1); case ANNOUNCE_ALL: break; case ANNOUNCE_SELF: /* * pass only prefix that have an aspath count * of zero this is equal to the ^$ regex. */ if (p->aspath->aspath->ascnt != 0) return (0); break; } /* well known communities */ if (rde_filter_community(p->aspath, COMMUNITY_WELLKNOWN, COMMUNITY_NO_ADVERTISE)) return (0); if (peer->conf.ebgp && rde_filter_community(p->aspath, COMMUNITY_WELLKNOWN, COMMUNITY_NO_EXPORT)) return (0); if (peer->conf.ebgp && rde_filter_community(p->aspath, COMMUNITY_WELLKNOWN, COMMUNITY_NO_EXPSUBCONFED)) return (0); /* * Don't send messages back to originator * this is not specified in the RFC but seems logical. */ if ((attr = attr_optget(p->aspath, ATTR_ORIGINATOR_ID)) != NULL) { if (memcmp(attr->data, &peer->remote_bgpid, sizeof(peer->remote_bgpid)) == 0) { /* would cause loop don't send */ return (-1); } } return (1); } int up_generate(struct rde_peer *peer, struct rde_aspath *asp, struct bgpd_addr *addr, u_int8_t prefixlen) { struct update_attr *ua = NULL; struct update_prefix *up; if (asp) { ua = calloc(1, sizeof(struct update_attr)); if (ua == NULL) fatal("up_generate_updates"); if (up_generate_attr(peer, ua, asp, addr->af) == -1) { log_warnx("generation of bgp path attributes failed"); free(ua); return (-1); } /* * use aspath_hash as attr_hash, this may be unoptimal * but currently I don't care. */ ua->attr_hash = hash32_buf(ua->attr, ua->attr_len, HASHINIT); if (ua->mpattr) ua->attr_hash = hash32_buf(ua->mpattr, ua->mpattr_len, ua->attr_hash); } up = calloc(1, sizeof(struct update_prefix)); if (up == NULL) fatal("up_generate_updates"); up->prefix = *addr; up->prefixlen = prefixlen; if (up_add(peer, up, ua) == -1) return (-1); return (0); } void up_generate_updates(struct filter_head *rules, struct rde_peer *peer, struct prefix *new, struct prefix *old) { struct rde_aspath *asp; struct bgpd_addr addr; if (peer->state != PEER_UP) return; if (new == NULL) { if (up_test_update(peer, old) != 1) return; pt_getaddr(old->prefix, &addr); if (rde_filter(NULL, rules, peer, old->aspath, &addr, old->prefix->prefixlen, old->aspath->peer, DIR_OUT) == ACTION_DENY) return; /* withdraw prefix */ up_generate(peer, NULL, &addr, old->prefix->prefixlen); } else { switch (up_test_update(peer, new)) { case 1: break; case 0: up_generate_updates(rules, peer, NULL, old); return; case -1: return; } pt_getaddr(new->prefix, &addr); if (rde_filter(&asp, rules, peer, new->aspath, &addr, new->prefix->prefixlen, new->aspath->peer, DIR_OUT) == ACTION_DENY) { path_put(asp); up_generate_updates(rules, peer, NULL, old); return; } /* generate update */ if (asp != NULL) { up_generate(peer, asp, &addr, new->prefix->prefixlen); path_put(asp); } else up_generate(peer, new->aspath, &addr, new->prefix->prefixlen); } } /* send a default route to the specified peer */ void up_generate_default(struct filter_head *rules, struct rde_peer *peer, sa_family_t af) { struct rde_aspath *asp, *fasp; struct bgpd_addr addr; if (peer->capa_received.mp_v4 == SAFI_NONE && peer->capa_received.mp_v6 != SAFI_NONE && af == AF_INET) return; if (peer->capa_received.mp_v6 == SAFI_NONE && af == AF_INET6) return; asp = path_get(); asp->aspath = aspath_get(NULL, 0); asp->origin = ORIGIN_IGP; /* the other default values are OK, nexthop is once again NULL */ /* * XXX apply default overrides. Not yet possible, mainly a parse.y * problem. */ /* rde_apply_set(asp, set, af, NULL ???, DIR_IN); */ /* filter as usual */ bzero(&addr, sizeof(addr)); addr.af = af; if (rde_filter(&fasp, rules, peer, asp, &addr, 0, NULL, DIR_OUT) == ACTION_DENY) { path_put(fasp); path_put(asp); return; } /* generate update */ if (fasp != NULL) up_generate(peer, fasp, &addr, 0); else up_generate(peer, asp, &addr, 0); /* no longer needed */ path_put(fasp); path_put(asp); } u_char up_attr_buf[4096]; /* only for IPv4 */ in_addr_t up_get_nexthop(struct rde_peer *peer, struct rde_aspath *a) { in_addr_t mask; /* nexthop, already network byte order */ if (a->flags & F_NEXTHOP_NOMODIFY) { /* no modify flag set */ if (a->nexthop == NULL) return (peer->local_v4_addr.v4.s_addr); else return (a->nexthop->exit_nexthop.v4.s_addr); } else if (a->flags & F_NEXTHOP_SELF) return (peer->local_v4_addr.v4.s_addr); else if (!peer->conf.ebgp) { /* * If directly connected use peer->local_v4_addr * this is only true for announced networks. */ if (a->nexthop == NULL) return (peer->local_v4_addr.v4.s_addr); else if (a->nexthop->exit_nexthop.v4.s_addr == peer->remote_addr.v4.s_addr) /* * per RFC: if remote peer address is equal to * the nexthop set the nexthop to our local address. * This reduces the risk of routing loops. */ return (peer->local_v4_addr.v4.s_addr); else return (a->nexthop->exit_nexthop.v4.s_addr); } else if (peer->conf.distance == 1) { /* ebgp directly connected */ if (a->nexthop != NULL && a->nexthop->flags & NEXTHOP_CONNECTED) { mask = htonl( prefixlen2mask(a->nexthop->nexthop_netlen)); if ((peer->remote_addr.v4.s_addr & mask) == (a->nexthop->nexthop_net.v4.s_addr & mask)) /* nexthop and peer are in the same net */ return (a->nexthop->exit_nexthop.v4.s_addr); else return (peer->local_v4_addr.v4.s_addr); } else return (peer->local_v4_addr.v4.s_addr); } else /* ebgp multihop */ /* * For ebgp multihop nh->flags should never have * NEXTHOP_CONNECTED set so it should be possible to unify the * two ebgp cases. But this is safe and RFC compliant. */ return (peer->local_v4_addr.v4.s_addr); } int up_generate_mp_reach(struct rde_peer *peer, struct update_attr *upa, struct rde_aspath *a, sa_family_t af) { u_int16_t tmp; switch (af) { case AF_INET6: upa->mpattr_len = 21; /* AFI + SAFI + NH LEN + NH + Reserved */ upa->mpattr = malloc(upa->mpattr_len); if (upa->mpattr == NULL) fatal("up_generate_mp_reach"); tmp = htons(AFI_IPv6); memcpy(upa->mpattr, &tmp, sizeof(tmp)); upa->mpattr[2] = SAFI_UNICAST; upa->mpattr[3] = sizeof(struct in6_addr); upa->mpattr[20] = 0; /* Reserved must be 0 */ /* nexthop dance see also up_get_nexthop() */ if (peer->conf.ebgp == 0) { /* ibgp */ if (a->nexthop == NULL || (a->nexthop->exit_nexthop.af == AF_INET6 && memcmp(&a->nexthop->exit_nexthop.v6, &peer->remote_addr.v6, sizeof(struct in6_addr)))) memcpy(&upa->mpattr[4], &peer->local_v6_addr.v6, sizeof(struct in6_addr)); else memcpy(&upa->mpattr[4], &a->nexthop->exit_nexthop.v6, sizeof(struct in6_addr)); } else if (peer->conf.distance == 1) { /* ebgp directly connected */ if (a->nexthop != NULL && a->nexthop->flags & NEXTHOP_CONNECTED) if (prefix_compare(&peer->remote_addr, &a->nexthop->nexthop_net, a->nexthop->nexthop_netlen) == 0) { /* * nexthop and peer are in the same * subnet */ memcpy(&upa->mpattr[4], &a->nexthop->exit_nexthop.v6, sizeof(struct in6_addr)); return (0); } memcpy(&upa->mpattr[4], &peer->local_v6_addr.v6, sizeof(struct in6_addr)); } else /* ebgp multihop */ memcpy(&upa->mpattr[4], &peer->local_v6_addr.v6, sizeof(struct in6_addr)); return (0); default: break; } return (-1); } int up_generate_attr(struct rde_peer *peer, struct update_attr *upa, struct rde_aspath *a, sa_family_t af) { struct attr *oa, *newaggr = NULL; u_char *pdata; u_int32_t tmp32; in_addr_t nexthop; int r, ismp = 0, neednewpath = 0; u_int16_t len = sizeof(up_attr_buf), wlen = 0, plen; u_int8_t l; /* origin */ if ((r = attr_write(up_attr_buf + wlen, len, ATTR_WELL_KNOWN, ATTR_ORIGIN, &a->origin, 1)) == -1) return (-1); wlen += r; len -= r; /* aspath */ if (!peer->conf.ebgp || rde_decisionflags() & BGPD_FLAG_DECISION_TRANS_AS) pdata = aspath_prepend(a->aspath, rde_local_as(), 0, &plen); else pdata = aspath_prepend(a->aspath, rde_local_as(), 1, &plen); if (!rde_as4byte(peer)) pdata = aspath_deflate(pdata, &plen, &neednewpath); if ((r = attr_write(up_attr_buf + wlen, len, ATTR_WELL_KNOWN, ATTR_ASPATH, pdata, plen)) == -1) return (-1); wlen += r; len -= r; free(pdata); switch (af) { case AF_INET: nexthop = up_get_nexthop(peer, a); if ((r = attr_write(up_attr_buf + wlen, len, ATTR_WELL_KNOWN, ATTR_NEXTHOP, &nexthop, 4)) == -1) return (-1); wlen += r; len -= r; break; default: ismp = 1; break; } /* * The old MED from other peers MUST not be announced to others * unless the MED is originating from us or the peer is an IBGP one. */ if (a->flags & F_ATTR_MED && (peer->conf.ebgp == 0 || a->flags & F_ATTR_MED_ANNOUNCE)) { tmp32 = htonl(a->med); if ((r = attr_write(up_attr_buf + wlen, len, ATTR_OPTIONAL, ATTR_MED, &tmp32, 4)) == -1) return (-1); wlen += r; len -= r; } if (peer->conf.ebgp == 0) { /* local preference, only valid for ibgp */ tmp32 = htonl(a->lpref); if ((r = attr_write(up_attr_buf + wlen, len, ATTR_WELL_KNOWN, ATTR_LOCALPREF, &tmp32, 4)) == -1) return (-1); wlen += r; len -= r; } /* * dump all other path attributes. Following rules apply: * 1. well-known attrs: ATTR_ATOMIC_AGGREGATE and ATTR_AGGREGATOR * pass unmodified (enforce flags to correct values) * Actually ATTR_AGGREGATOR may be deflated for OLD 2-byte peers. * 2. non-transitive attrs: don't re-announce to ebgp peers * 3. transitive known attrs: announce unmodified * 4. transitive unknown attrs: set partial bit and re-announce */ for (l = 0; l < a->others_len; l++) { if ((oa = a->others[l]) == NULL) break; switch (oa->type) { case ATTR_ATOMIC_AGGREGATE: if ((r = attr_write(up_attr_buf + wlen, len, ATTR_WELL_KNOWN, ATTR_ATOMIC_AGGREGATE, NULL, 0)) == -1) return (-1); break; case ATTR_AGGREGATOR: if (!rde_as4byte(peer)) { /* need to deflate the aggregator */ u_int8_t t[6]; u_int16_t tas; if ((!(oa->flags & ATTR_TRANSITIVE)) && peer->conf.ebgp != 0) { r = 0; break; } memcpy(&tmp32, oa->data, sizeof(tmp32)); if (ntohl(tmp32) > USHRT_MAX) { tas = htons(AS_TRANS); newaggr = oa; } else tas = htons(ntohl(tmp32)); memcpy(t, &tas, sizeof(tas)); memcpy(t + sizeof(tas), oa->data + sizeof(tmp32), oa->len - sizeof(tmp32)); if ((r = attr_write(up_attr_buf + wlen, len, oa->flags, oa->type, &t, sizeof(t))) == -1) return (-1); break; } /* FALLTHROUGH */ case ATTR_COMMUNITIES: case ATTR_ORIGINATOR_ID: case ATTR_CLUSTER_LIST: if ((!(oa->flags & ATTR_TRANSITIVE)) && peer->conf.ebgp != 0) { r = 0; break; } if ((r = attr_write(up_attr_buf + wlen, len, oa->flags, oa->type, oa->data, oa->len)) == -1) return (-1); break; default: /* unknown attribute */ if (!(oa->flags & ATTR_TRANSITIVE)) { /* * RFC 1771: * Unrecognized non-transitive optional * attributes must be quietly ignored and * not passed along to other BGP peers. */ r = 0; break; } if ((r = attr_write(up_attr_buf + wlen, len, oa->flags | ATTR_PARTIAL, oa->type, oa->data, oa->len)) == -1) return (-1); break; } wlen += r; len -= r; } /* NEW to OLD conversion when going sending stuff to a 2byte AS peer */ if (neednewpath) { if (!peer->conf.ebgp || rde_decisionflags() & BGPD_FLAG_DECISION_TRANS_AS) pdata = aspath_prepend(a->aspath, rde_local_as(), 0, &plen); else pdata = aspath_prepend(a->aspath, rde_local_as(), 1, &plen); if (plen == 0) r = 0; else if ((r = attr_write(up_attr_buf + wlen, len, ATTR_OPTIONAL|ATTR_TRANSITIVE, ATTR_NEW_ASPATH, pdata, plen)) == -1) return (-1); wlen += r; len -= r; free(pdata); } if (newaggr) { if ((r = attr_write(up_attr_buf + wlen, len, ATTR_OPTIONAL|ATTR_TRANSITIVE, ATTR_NEW_AGGREGATOR, newaggr->data, newaggr->len)) == -1) return (-1); wlen += r; len -= r; } /* write mp attribute to different buffer */ if (ismp) if (up_generate_mp_reach(peer, upa, a, AF_INET6) == -1) return (-1); /* the bgp path attributes are now stored in the global buf */ upa->attr = malloc(wlen); if (upa->attr == NULL) fatal("up_generate_attr"); memcpy(upa->attr, up_attr_buf, wlen); upa->attr_len = wlen; return (wlen); } #define MIN_PREFIX_LEN 5 /* 1 byte prefix length + 4 bytes addr */ int up_dump_prefix(u_char *buf, int len, struct uplist_prefix *prefix_head, struct rde_peer *peer) { struct update_prefix *upp; int r, wpos = 0; while ((upp = TAILQ_FIRST(prefix_head)) != NULL) { if ((r = prefix_write(buf + wpos, len - wpos, &upp->prefix, upp->prefixlen)) == -1) break; wpos += r; if (RB_REMOVE(uptree_prefix, &peer->up_prefix, upp) == NULL) log_warnx("dequeuing update failed."); TAILQ_REMOVE(upp->prefix_h, upp, prefix_l); peer->up_pcnt--; if (upp->prefix_h == &peer->withdraws || upp->prefix_h == &peer->withdraws6) { peer->up_wcnt--; peer->prefix_sent_withdraw++; } else { peer->up_nlricnt--; peer->prefix_sent_update++; } free(upp); } return (wpos); } int up_dump_attrnlri(u_char *buf, int len, struct rde_peer *peer) { struct update_attr *upa; int r, wpos; u_int16_t attr_len; /* * It is possible that a queued path attribute has no nlri prefix. * Ignore and remove those path attributes. */ while ((upa = TAILQ_FIRST(&peer->updates)) != NULL) if (TAILQ_EMPTY(&upa->prefix_h)) { if (RB_REMOVE(uptree_attr, &peer->up_attrs, upa) == NULL) log_warnx("dequeuing update failed."); TAILQ_REMOVE(&peer->updates, upa, attr_l); free(upa->attr); free(upa->mpattr); free(upa); peer->up_acnt--; } else break; if (upa == NULL || upa->attr_len + MIN_PREFIX_LEN > len) { /* * either no packet or not enough space. * The length field needs to be set to zero else it would be * an invalid bgp update. */ bzero(buf, 2); return (2); } /* first dump the 2-byte path attribute length */ attr_len = htons(upa->attr_len); memcpy(buf, &attr_len, 2); wpos = 2; /* then the path attributes themselves */ memcpy(buf + wpos, upa->attr, upa->attr_len); wpos += upa->attr_len; /* last but not least dump the nlri */ r = up_dump_prefix(buf + wpos, len - wpos, &upa->prefix_h, peer); wpos += r; /* now check if all prefixes were written */ if (TAILQ_EMPTY(&upa->prefix_h)) { if (RB_REMOVE(uptree_attr, &peer->up_attrs, upa) == NULL) log_warnx("dequeuing update failed."); TAILQ_REMOVE(&peer->updates, upa, attr_l); free(upa->attr); free(upa->mpattr); free(upa); peer->up_acnt--; } return (wpos); } u_char * up_dump_mp_unreach(u_char *buf, u_int16_t *len, struct rde_peer *peer) { int wpos; u_int16_t datalen, tmp; u_int16_t attrlen = 2; /* attribute header (without len) */ u_int8_t flags = ATTR_OPTIONAL; /* * reserve space for withdraw len, attr len, the attribute header * and the mp attribute header */ wpos = 2 + 2 + 4 + 3; if (*len < wpos) return (NULL); datalen = up_dump_prefix(buf + wpos, *len - wpos, &peer->withdraws6, peer); if (datalen == 0) return (NULL); datalen += 3; /* afi + safi */ if (datalen > 255) { attrlen += 2 + datalen; flags |= ATTR_EXTLEN; } else { attrlen += 1 + datalen; buf++; } /* prepend header, need to do it reverse */ /* safi & afi */ buf[--wpos] = SAFI_UNICAST; wpos -= sizeof(u_int16_t); tmp = htons(AFI_IPv6); memcpy(buf + wpos, &tmp, sizeof(u_int16_t)); /* attribute length */ if (datalen > 255) { wpos -= sizeof(u_int16_t); tmp = htons(datalen); memcpy(buf + wpos, &tmp, sizeof(u_int16_t)); } else buf[--wpos] = (u_char)datalen; /* mp attribute */ buf[--wpos] = (u_char)ATTR_MP_UNREACH_NLRI; buf[--wpos] = flags; /* attribute length */ wpos -= sizeof(u_int16_t); tmp = htons(attrlen); memcpy(buf + wpos, &tmp, sizeof(u_int16_t)); /* no IPv4 withdraws */ wpos -= sizeof(u_int16_t); bzero(buf + wpos, sizeof(u_int16_t)); if (wpos < 0) fatalx("up_dump_mp_unreach: buffer underflow"); /* total length includes the two 2-bytes length fields. */ *len = attrlen + 2 * sizeof(u_int16_t); return (buf); } u_char * up_dump_mp_reach(u_char *buf, u_int16_t *len, struct rde_peer *peer) { struct update_attr *upa; int wpos; u_int16_t datalen, tmp; u_int8_t flags = ATTR_OPTIONAL; /* * It is possible that a queued path attribute has no nlri prefix. * Ignore and remove those path attributes. */ while ((upa = TAILQ_FIRST(&peer->updates6)) != NULL) if (TAILQ_EMPTY(&upa->prefix_h)) { if (RB_REMOVE(uptree_attr, &peer->up_attrs, upa) == NULL) log_warnx("dequeuing update failed."); TAILQ_REMOVE(&peer->updates6, upa, attr_l); free(upa->attr); free(upa->mpattr); free(upa); peer->up_acnt--; } else break; if (upa == NULL) return (NULL); /* * reserve space for attr len, the attributes, the * mp attribute and the attribute header */ wpos = 2 + 2 + upa->attr_len + 4 + upa->mpattr_len; if (*len < wpos) return (NULL); datalen = up_dump_prefix(buf + wpos, *len - wpos, &upa->prefix_h, peer); if (datalen == 0) return (NULL); if (upa->mpattr_len == 0 || upa->mpattr == NULL) fatalx("mulitprotocol update without MP attrs"); datalen += upa->mpattr_len; wpos -= upa->mpattr_len; memcpy(buf + wpos, upa->mpattr, upa->mpattr_len); if (datalen > 255) { wpos -= 2; tmp = htons(datalen); memcpy(buf + wpos, &tmp, sizeof(tmp)); datalen += 4; flags |= ATTR_EXTLEN; } else { buf[--wpos] = (u_char)datalen; datalen += 3; } buf[--wpos] = (u_char)ATTR_MP_REACH_NLRI; buf[--wpos] = flags; datalen += upa->attr_len; wpos -= upa->attr_len; memcpy(buf + wpos, upa->attr, upa->attr_len); if (wpos < 4) fatalx("Grrr, mp_reach buffer fucked up"); wpos -= 2; tmp = htons(datalen); memcpy(buf + wpos, &tmp, sizeof(tmp)); wpos -= 2; bzero(buf + wpos, 2); /* now check if all prefixes were written */ if (TAILQ_EMPTY(&upa->prefix_h)) { if (RB_REMOVE(uptree_attr, &peer->up_attrs, upa) == NULL) log_warnx("dequeuing update failed."); TAILQ_REMOVE(&peer->updates6, upa, attr_l); free(upa->attr); free(upa->mpattr); free(upa); peer->up_acnt--; } *len = datalen + 4; return (buf + wpos); }