X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/78a7085778868f1bc0e5e5542b7e208f943e3778..3ea85f7c57f8d555396feb5121e7253f04ee6774:/bgp.c diff --git a/bgp.c b/bgp.c index ea15faf..f0ff879 100644 --- a/bgp.c +++ b/bgp.c @@ -32,8 +32,11 @@ static void bgp_set_retry(struct bgp_peer *peer); static void bgp_cidr(in_addr_t ip, in_addr_t mask, struct bgp_ip_prefix *pfx); static struct bgp_route_list *bgp_insert_route(struct bgp_route_list *head, struct bgp_route_list *new); +static struct bgp_route6_list *bgp_insert_route6(struct bgp_route6_list *head, + struct bgp_route6_list *new); static void bgp_free_routes(struct bgp_route_list *routes); +static void bgp_free_routes6(struct bgp_route6_list *routes); static char const *bgp_msg_type_str(uint8_t type); static int bgp_connect(struct bgp_peer *peer); static int bgp_handle_connect(struct bgp_peer *peer); @@ -43,6 +46,7 @@ static int bgp_handle_input(struct bgp_peer *peer); static int bgp_send_open(struct bgp_peer *peer); static int bgp_send_keepalive(struct bgp_peer *peer); static int bgp_send_update(struct bgp_peer *peer); +static int bgp_send_update6(struct bgp_peer *peer); static int bgp_send_notification(struct bgp_peer *peer, uint8_t code, uint8_t subcode); static int bgp_send_notification_full(struct bgp_peer *peer, uint8_t code, @@ -50,6 +54,7 @@ static int bgp_send_notification_full(struct bgp_peer *peer, uint8_t code, static uint16_t our_as; static struct bgp_route_list *bgp_routes = 0; +static struct bgp_route6_list *bgp_routes6 = 0; int bgp_configured = 0; struct bgp_peer *bgp_peers = 0; @@ -90,6 +95,7 @@ int bgp_setup(int as) return 0; bgp_routes = 0; + bgp_routes6 = 0; bgp_configured = 0; /* set by bgp_start */ return 1; @@ -193,15 +199,6 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, ADD_ATTRIBUTE(); - /* NEXT_HOP */ - a.flags = BGP_PATH_ATTR_FLAG_TRANS; - a.code = BGP_PATH_ATTR_CODE_NEXT_HOP; - ip = my_address; /* we're it */ - a.data.s.len = sizeof(ip); - memcpy(a.data.s.value, &ip, sizeof(ip)); - - ADD_ATTRIBUTE(); - /* MULTI_EXIT_DISC */ a.flags = BGP_PATH_ATTR_FLAG_OPTIONAL; a.code = BGP_PATH_ATTR_CODE_MULTI_EXIT_DISC; @@ -231,6 +228,18 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, ADD_ATTRIBUTE(); + /* remember the len before adding NEXT_HOP */ + peer->path_attr_len_without_nexthop = peer->path_attr_len; + + /* NEXT_HOP */ + a.flags = BGP_PATH_ATTR_FLAG_TRANS; + a.code = BGP_PATH_ATTR_CODE_NEXT_HOP; + ip = my_address; /* we're it */ + a.data.s.len = sizeof(ip); + memcpy(a.data.s.value, &ip, sizeof(ip)); + + ADD_ATTRIBUTE(); + if (!(peer->path_attrs = malloc(peer->path_attr_len))) { LOG(0, 0, 0, "Can't allocate path_attrs for %s (%s)\n", @@ -241,6 +250,53 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, memcpy(peer->path_attrs, path_attrs, peer->path_attr_len); + /* multiprotocol attributes initialization */ + if (config->ipv6_prefix.s6_addr[0]) + { + struct bgp_attr_mp_reach_nlri_partial mp_reach_nlri_partial; + struct bgp_attr_mp_unreach_nlri_partial mp_unreach_nlri_partial; + + a.flags = BGP_PATH_ATTR_FLAG_OPTIONAL; + a.code = BGP_PATH_ATTR_CODE_MP_REACH_NLRI; + a.data.s.len = 0; /* will be set on UPDATE */ + + mp_reach_nlri_partial.afi = htons(BGP_MP_AFI_IPv6); + mp_reach_nlri_partial.safi = BGP_MP_SAFI_UNICAST; + mp_reach_nlri_partial.reserved = 0; + mp_reach_nlri_partial.next_hop_len = 16; + + /* use the defined nexthop6, or our address in ipv6_prefix */ + if (config->nexthop6_address.s6_addr[0]) + memcpy(&mp_reach_nlri_partial.next_hop, + &config->nexthop6_address.s6_addr, 16); + else + { + /* our address is ipv6prefix::1 */ + memcpy(&mp_reach_nlri_partial.next_hop, + &config->ipv6_prefix.s6_addr, 16); + mp_reach_nlri_partial.next_hop[15] = 1; + } + + memcpy(&a.data.s.value, &mp_reach_nlri_partial, + sizeof(struct bgp_attr_mp_reach_nlri_partial)); + memcpy(&peer->mp_reach_nlri_partial, &a, + BGP_PATH_ATTR_MP_REACH_NLRI_PARTIAL_SIZE); + + a.flags = BGP_PATH_ATTR_FLAG_OPTIONAL | BGP_PATH_ATTR_FLAG_EXTLEN; + a.code = BGP_PATH_ATTR_CODE_MP_UNREACH_NLRI; + a.data.e.len = 0; /* will be set on UPDATE */ + + mp_unreach_nlri_partial.afi = htons(BGP_MP_AFI_IPv6); + mp_unreach_nlri_partial.safi = BGP_MP_SAFI_UNICAST; + + memcpy(&a.data.e.value, &mp_unreach_nlri_partial, + sizeof(struct bgp_attr_mp_unreach_nlri_partial)); + memcpy(&peer->mp_unreach_nlri_partial, &a, + BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE); + } + + peer->mp_handling = HandlingUnknown; + LOG(4, 0, 0, "Initiating BGP connection to %s (routing %s)\n", name, enable ? "enabled" : "suspended"); @@ -269,6 +325,8 @@ static void bgp_clear(struct bgp_peer *peer) bgp_free_routes(peer->routes); peer->routes = 0; + bgp_free_routes6(peer->routes6); + peer->routes6 = 0; peer->outbuf->packet.header.len = 0; peer->outbuf->done = 0; @@ -376,6 +434,33 @@ static struct bgp_route_list *bgp_insert_route(struct bgp_route_list *head, return head; } +/* insert route6 into list; sorted */ +static struct bgp_route6_list *bgp_insert_route6(struct bgp_route6_list *head, + struct bgp_route6_list *new) +{ + struct bgp_route6_list *p = head; + struct bgp_route6_list *e = 0; + + while (p && memcmp(&p->dest, &new->dest, sizeof(p->dest)) < 0) + { + e = p; + p = p->next; + } + + if (e) + { + new->next = e->next; + e->next = new; + } + else + { + new->next = head; + head = new; + } + + return head; +} + /* add route to list for peers */ /* * Note: this doesn't do route aggregation, nor drop routes if a less @@ -428,6 +513,58 @@ int bgp_add_route(in_addr_t ip, in_addr_t mask) return 1; } +/* add route to list for peers */ +/* + * Note: same provisions as above + */ +int bgp_add_route6(struct in6_addr ip, int prefixlen) +{ + struct bgp_route6_list *r = bgp_routes6; + struct bgp_route6_list add; + int i; + char ipv6addr[INET6_ADDRSTRLEN]; + + memcpy(&add.dest.prefix, &ip.s6_addr, 16); + add.dest.len = prefixlen; + add.next = 0; + + /* check for duplicate */ + while (r) + { + i = memcmp(&r->dest, &add.dest, sizeof(r->dest)); + if (!i) + return 1; /* already covered */ + + if (i > 0) + break; + + r = r->next; + } + + /* insert into route list; sorted */ + if (!(r = malloc(sizeof(*r)))) + { + LOG(0, 0, 0, "Can't allocate route for %s/%d (%s)\n", + inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN), add.dest.len, + strerror(errno)); + + return 0; + } + + memcpy(r, &add, sizeof(*r)); + bgp_routes6 = bgp_insert_route6(bgp_routes6, r); + + /* flag established peers for update */ + for (i = 0; i < BGP_NUM_PEERS; i++) + if (bgp_peers[i].state == Established) + bgp_peers[i].update_routes6 = 1; + + LOG(4, 0, 0, "Registered BGP route %s/%d\n", + inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN), add.dest.len); + + return 1; +} + /* remove route from list for peers */ int bgp_del_route(in_addr_t ip, in_addr_t mask) { @@ -477,6 +614,57 @@ int bgp_del_route(in_addr_t ip, in_addr_t mask) return 1; } +/* remove route from list for peers */ +int bgp_del_route6(struct in6_addr ip, int prefixlen) +{ + struct bgp_route6_list *r = bgp_routes6; + struct bgp_route6_list *e = 0; + struct bgp_route6_list del; + int i; + char ipv6addr[INET6_ADDRSTRLEN]; + + memcpy(&del.dest.prefix, &ip.s6_addr, 16); + del.dest.len = prefixlen; + del.next = 0; + + /* find entry in routes list and remove */ + while (r) + { + i = memcmp(&r->dest, &del.dest, sizeof(r->dest)); + if (!i) + { + if (e) + e->next = r->next; + else + bgp_routes6 = r->next; + + free(r); + break; + } + + e = r; + + if (i > 0) + r = 0; /* stop */ + else + r = r->next; + } + + /* not found */ + if (!r) + return 1; + + /* flag established peers for update */ + for (i = 0; i < BGP_NUM_PEERS; i++) + if (bgp_peers[i].state == Established) + bgp_peers[i].update_routes6 = 1; + + LOG(4, 0, 0, "Removed BGP route %s/%d\n", + inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN), del.dest.len); + + return 1; +} + /* enable or disable routing */ void bgp_enable_routing(int enable) { @@ -621,6 +809,14 @@ int bgp_process(uint32_t events[]) continue; } + /* process pending IPv6 updates */ + if (peer->update_routes6 + && !peer->outbuf->packet.header.len) /* ditto */ + { + if (!bgp_send_update6(peer)) + continue; + } + /* process timers */ if (peer->state == Established) { @@ -664,6 +860,17 @@ static void bgp_free_routes(struct bgp_route_list *routes) } } +static void bgp_free_routes6(struct bgp_route6_list *routes) +{ + struct bgp_route6_list *tmp; + + while ((tmp = routes)) + { + routes = tmp->next; + free(tmp); + } +} + char const *bgp_state_str(enum bgp_state state) { switch (state) @@ -762,8 +969,6 @@ static int bgp_connect(struct bgp_peer *peer) LOG(4, 0, 0, "BGP peer %s: state Active\n", inet_ntoa(addr.sin_addr)); - peer->handle_ipv6_routes = 0; - return bgp_send_open(peer); } @@ -787,8 +992,6 @@ static int bgp_handle_connect(struct bgp_peer *peer) LOG(4, 0, 0, "BGP peer %s: state Active\n", peer->name); - peer->handle_ipv6_routes = 0; - return bgp_send_open(peer); } @@ -1044,7 +1247,7 @@ static int bgp_handle_input(struct bgp_peer *peer) mp_cap = (struct bgp_mp_cap_param *)&capability->value; /* the only tuple we support */ - if (ntohs(mp_cap->afi) != AF_INET6 && mp_cap->safi != BGP_MP_SAFI_UNICAST) + if (ntohs(mp_cap->afi) != BGP_MP_AFI_IPv6 && mp_cap->safi != BGP_MP_SAFI_UNICAST) { LOG(4, 0, 0, "Unsupported multiprotocol AFI %d and SAFI %d from BGP peer %s\n", mp_cap->afi, mp_cap->safi, peer->name); @@ -1055,7 +1258,7 @@ static int bgp_handle_input(struct bgp_peer *peer) continue; } - peer->handle_ipv6_routes = 1; + peer->mp_handling = HandleIPv6Routes; } } @@ -1094,13 +1297,22 @@ static int bgp_handle_input(struct bgp_peer *peer) } if (notification->error_code == BGP_ERR_OPEN - && notification->subcode == BGP_ERR_OPN_UNSUP_CAP) + && notification->error_subcode == BGP_ERR_OPN_UNSUP_PARAM) + { + LOG(4, 0, 0, "BGP peer %s doesn't support BGP Capabilities\n", peer->name); + peer->mp_handling = DoesntHandleIPv6Routes; + bgp_restart(peer); + return 0; + } + + if (notification->error_code == BGP_ERR_OPEN + && notification->error_subcode == BGP_ERR_OPN_UNSUP_CAP) { /* the only capability we advertise is this one, so upon receiving an "unsupported capability" message, we disable IPv6 routes for this peer */ LOG(4, 0, 0, "BGP peer %s doesn't support IPv6 routes advertisement\n", peer->name); - peer->handle_ipv6_routes = 0; + peer->mp_handling = DoesntHandleIPv6Routes; break; } @@ -1134,7 +1346,7 @@ static int bgp_handle_input(struct bgp_peer *peer) static int bgp_send_open(struct bgp_peer *peer) { struct bgp_data_open data; - struct bgp_mp_cap_param mp_ipv6 = { htons(AF_INET6), 0, BGP_MP_SAFI_UNICAST }; + struct bgp_mp_cap_param mp_ipv6 = { htons(BGP_MP_AFI_IPv6), 0, BGP_MP_SAFI_UNICAST }; struct bgp_capability cap_mp_ipv6; struct bgp_opt_param param_cap_mp_ipv6; uint16_t len = sizeof(peer->outbuf->packet.header); @@ -1149,20 +1361,28 @@ static int bgp_send_open(struct bgp_peer *peer) data.hold_time = htons(peer->hold); data.identifier = my_address; - /* construct the param and capability */ - cap_mp_ipv6.code = BGP_CAP_CODE_MP; - cap_mp_ipv6.len = sizeof(mp_ipv6); - memcpy(&cap_mp_ipv6.value, &mp_ipv6, cap_mp_ipv6.len); + /* if we know peer doesn't support MP (mp_handling == DoesntHandleIPv6Routes) + then don't add this parameter */ + if (peer->mp_handling == HandlingUnknown + || peer->mp_handling == HandleIPv6Routes) + { + /* construct the param and capability */ + cap_mp_ipv6.code = BGP_CAP_CODE_MP; + cap_mp_ipv6.len = sizeof(mp_ipv6); + memcpy(&cap_mp_ipv6.value, &mp_ipv6, cap_mp_ipv6.len); - param_cap_mp_ipv6.type = BGP_PARAM_TYPE_CAPABILITY; - param_cap_mp_ipv6.len = 2 + sizeof(mp_ipv6); - memcpy(¶m_cap_mp_ipv6.value, &cap_mp_ipv6, param_cap_mp_ipv6.len); + param_cap_mp_ipv6.type = BGP_PARAM_TYPE_CAPABILITY; + param_cap_mp_ipv6.len = 2 + sizeof(mp_ipv6); + memcpy(¶m_cap_mp_ipv6.value, &cap_mp_ipv6, param_cap_mp_ipv6.len); - data.opt_len = 2 + param_cap_mp_ipv6.len; - memcpy(&data.opt_params, ¶m_cap_mp_ipv6, data.opt_len); + data.opt_len = 2 + param_cap_mp_ipv6.len; + memcpy(&data.opt_params, ¶m_cap_mp_ipv6, data.opt_len); + } + else + data.opt_len = 0; - memcpy(peer->outbuf->packet.data, &data, BGP_DATA_OPEN_SIZE); - len += BGP_DATA_OPEN_SIZE; + memcpy(peer->outbuf->packet.data, &data, BGP_DATA_OPEN_SIZE + data.opt_len); + len += BGP_DATA_OPEN_SIZE + data.opt_len; peer->outbuf->packet.header.len = htons(len); peer->outbuf->done = 0; @@ -1329,6 +1549,167 @@ static int bgp_send_update(struct bgp_peer *peer) return bgp_write(peer); } +/* send/buffer UPDATE message for IPv6 routes */ +static int bgp_send_update6(struct bgp_peer *peer) +{ + uint16_t unf_len = 0; + uint16_t attr_len; + char *unreach_len; + uint8_t reach_len; + uint16_t len = sizeof(peer->outbuf->packet.header); + struct bgp_route6_list *have = peer->routes6; + struct bgp_route6_list *want = peer->routing ? bgp_routes6 : 0; + struct bgp_route6_list *e = 0; + struct bgp_route6_list *add = 0; + int s; + char ipv6addr[INET6_ADDRSTRLEN]; + + char *data = (char *) &peer->outbuf->packet.data; + + /* need leave room for attr_len, bgp_path_attrs and one prefix */ + char *max = (char *) &peer->outbuf->packet.data + + sizeof(peer->outbuf->packet.data) + - sizeof(attr_len) - peer->path_attr_len_without_nexthop + - BGP_PATH_ATTR_MP_REACH_NLRI_PARTIAL_SIZE - sizeof(struct bgp_ip6_prefix); + + memset(peer->outbuf->packet.header.marker, 0xff, + sizeof(peer->outbuf->packet.header.marker)); + + peer->outbuf->packet.header.type = BGP_MSG_UPDATE; + + /* insert non-MP unf_len */ + memcpy(data, &unf_len, sizeof(unf_len)); + /* skip over attr_len too; will be filled when known */ + data += sizeof(unf_len) + sizeof(attr_len); + len += sizeof(unf_len) + sizeof(attr_len); + + /* copy usual attributes */ + memcpy(data, peer->path_attrs, peer->path_attr_len_without_nexthop); + data += peer->path_attr_len_without_nexthop; + len += peer->path_attr_len_without_nexthop; + + /* copy MP unreachable NLRI heading */ + memcpy(data, peer->mp_unreach_nlri_partial, + BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE); + /* remember where to update this attr len */ + unreach_len = data + 2; + data += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE; + len += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE; + + peer->update_routes6 = 0; /* tentatively clear */ + + /* find differences */ + while ((have || want) && data < (max - sizeof(struct bgp_ip6_prefix))) + { + if (have) + s = want + ? memcmp(&have->dest, &want->dest, sizeof(have->dest)) + : -1; + else + s = 1; + + if (s < 0) /* found one to delete */ + { + struct bgp_route6_list *tmp = have; + have = have->next; + + s = BGP_IP_PREFIX_SIZE(tmp->dest); + memcpy(data, &tmp->dest, s); + data += s; + unf_len += s; + len += s; + + LOG(5, 0, 0, "Withdrawing route %s/%d from BGP peer %s\n", + inet_ntop(AF_INET6, &tmp->dest.prefix, ipv6addr, INET6_ADDRSTRLEN), + tmp->dest.len, peer->name); + + free(tmp); + + if (e) + e->next = have; + else + peer->routes6 = have; + } + else + { + if (!s) /* same */ + { + e = have; /* stash the last found to relink above */ + have = have->next; + want = want->next; + } + else if (s > 0) /* addition reqd. */ + { + if (add) + { + peer->update_routes6 = 1; /* only one add per packet */ + if (!have) + break; + } + else + add = want; + + if (want) + want = want->next; + } + } + } + + if (have || want) + peer->update_routes6 = 1; /* more to do */ + + /* anything changed? */ + if (!(unf_len || add)) + return 1; + + /* go back and insert MP unf_len */ + unf_len += sizeof(struct bgp_attr_mp_unreach_nlri_partial); + unf_len = htons(unf_len); + memcpy(&unreach_len, &unf_len, sizeof(unf_len)); + + if (add) + { + if (!(e = malloc(sizeof(*e)))) + { + LOG(0, 0, 0, "Can't allocate route for %s/%d (%s)\n", + inet_ntop(AF_INET6, &add->dest.prefix, ipv6addr, INET6_ADDRSTRLEN), + add->dest.len, strerror(errno)); + + return 0; + } + + memcpy(e, add, sizeof(*e)); + e->next = 0; + peer->routes6 = bgp_insert_route6(peer->routes6, e); + + /* copy MP reachable NLRI heading */ + memcpy(data, peer->mp_reach_nlri_partial, + BGP_PATH_ATTR_MP_REACH_NLRI_PARTIAL_SIZE); + /* with proper len */ + reach_len = BGP_IP_PREFIX_SIZE(add->dest); + data[2] = reach_len; + data += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE; + len += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE; + + memcpy(data, &add->dest, reach_len); + data += reach_len; + len += reach_len; + + LOG(5, 0, 0, "Advertising route %s/%d to BGP peer %s\n", + inet_ntop(AF_INET6, &add->dest.prefix, ipv6addr, INET6_ADDRSTRLEN), + add->dest.len, peer->name); + } + + /* go back and insert attr_len */ + attr_len = htons(len - 4); + memcpy(&peer->outbuf->packet.data + 2, &attr_len, sizeof(attr_len)); + + peer->outbuf->packet.header.len = htons(len); + peer->outbuf->done = 0; + + return bgp_write(peer); +} + /* send/buffer NOTIFICATION message */ static int bgp_send_notification(struct bgp_peer *peer, uint8_t code, uint8_t subcode)