X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/db276bcc801cbd2662f90a6b22cfc551ecddbf0f..e7c9a1993778e9ac375d7f956dda7c3c802a83a5:/bgp.c diff --git a/bgp.c b/bgp.c index d9c5818..36894be 100644 --- a/bgp.c +++ b/bgp.c @@ -10,8 +10,6 @@ * nor RFC2385 (which requires a kernel patch on 2.4 kernels). */ -char const *cvs_id_bgp = "$Id: bgp.c,v 1.12 2005/09/02 23:39:36 bodea Exp $"; - #include #include #include @@ -22,6 +20,7 @@ char const *cvs_id_bgp = "$Id: bgp.c,v 1.12 2005/09/02 23:39:36 bodea Exp $"; #include #include #include +#include #include "l2tpns.h" #include "bgp.h" @@ -29,12 +28,12 @@ char const *cvs_id_bgp = "$Id: bgp.c,v 1.12 2005/09/02 23:39:36 bodea Exp $"; static void bgp_clear(struct bgp_peer *peer); 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_process_timers(struct bgp_peer *peer); 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); @@ -49,8 +48,6 @@ 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, - uint8_t subcode, char *notification_data, uint16_t data_len); static uint16_t our_as; static struct bgp_route_list *bgp_routes = 0; @@ -103,7 +100,7 @@ int bgp_setup(int as) /* start connection with a peer */ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, - int hold, int enable) + int hold, struct in_addr update_source, int enable) { struct hostent *h; int ibgp; @@ -132,6 +129,7 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, } memcpy(&peer->addr, h->h_addr, sizeof(peer->addr)); + peer->source_addr = update_source.s_addr; peer->as = as > 0 ? as : our_as; ibgp = peer->as == our_as; @@ -234,7 +232,14 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, /* NEXT_HOP */ a.flags = BGP_PATH_ATTR_FLAG_TRANS; a.code = BGP_PATH_ATTR_CODE_NEXT_HOP; - ip = my_address; /* we're it */ + if (config->nexthop_address) + { + ip = config->nexthop_address; + } + else + { + ip = my_address; /* we're it */ + } a.data.s.len = sizeof(ip); memcpy(a.data.s.value, &ip, sizeof(ip)); @@ -260,7 +265,7 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, 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(AF_INET6); + 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; @@ -286,7 +291,7 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, 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(AF_INET6); + 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, @@ -295,6 +300,8 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, 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"); @@ -385,26 +392,6 @@ static void bgp_set_retry(struct bgp_peer *peer) bgp_halt(peer); /* give up */ } -/* convert ip/mask to CIDR notation */ -static void bgp_cidr(in_addr_t ip, in_addr_t mask, struct bgp_ip_prefix *pfx) -{ - int i; - uint32_t b; - - /* convert to prefix notation */ - pfx->len = 32; - pfx->prefix = ip; - - if (!mask) /* bogus */ - mask = 0xffffffff; - - for (i = 0; i < 32 && ((b = ntohl(1 << i)), !(mask & b)); i++) - { - pfx->len--; - pfx->prefix &= ~b; - } -} - /* insert route into list; sorted */ static struct bgp_route_list *bgp_insert_route(struct bgp_route_list *head, struct bgp_route_list *new) @@ -466,13 +453,14 @@ static struct bgp_route6_list *bgp_insert_route6(struct bgp_route6_list *head, * that if that route is later deleted we don't have to be concerned * about adding back the more specific one). */ -int bgp_add_route(in_addr_t ip, in_addr_t mask) +int bgp_add_route(in_addr_t ip, int prefixlen) { struct bgp_route_list *r = bgp_routes; struct bgp_route_list add; int i; - bgp_cidr(ip, mask, &add.dest); + add.dest.prefix = ip; + add.dest.len = prefixlen; add.next = 0; /* check for duplicate */ @@ -554,7 +542,8 @@ int bgp_add_route6(struct in6_addr ip, int prefixlen) /* flag established peers for update */ for (i = 0; i < BGP_NUM_PEERS; i++) - if (bgp_peers[i].state == Established) + if (bgp_peers[i].state == Established + && bgp_peers[i].mp_handling == HandleIPv6Routes) bgp_peers[i].update_routes6 = 1; LOG(4, 0, 0, "Registered BGP route %s/%d\n", @@ -564,14 +553,15 @@ int bgp_add_route6(struct in6_addr ip, int prefixlen) } /* remove route from list for peers */ -int bgp_del_route(in_addr_t ip, in_addr_t mask) +int bgp_del_route(in_addr_t ip, int prefixlen) { struct bgp_route_list *r = bgp_routes; struct bgp_route_list *e = 0; struct bgp_route_list del; int i; - bgp_cidr(ip, mask, &del.dest); + del.dest.prefix = ip; + del.dest.len = prefixlen; del.next = 0; /* find entry in routes list and remove */ @@ -654,7 +644,8 @@ int bgp_del_route6(struct in6_addr ip, int prefixlen) /* flag established peers for update */ for (i = 0; i < BGP_NUM_PEERS; i++) - if (bgp_peers[i].state == Established) + if (bgp_peers[i].state == Established + && bgp_peers[i].mp_handling == HandleIPv6Routes) bgp_peers[i].update_routes6 = 1; LOG(4, 0, 0, "Removed BGP route %s/%d\n", @@ -816,35 +807,59 @@ int bgp_process(uint32_t events[]) } /* process timers */ - if (peer->state == Established) - { - if (time_now > peer->expire_time) - { - LOG(1, 0, 0, "No message from BGP peer %s in %ds\n", - peer->name, peer->hold); + bgp_process_timers(peer); + } - bgp_send_notification(peer, BGP_ERR_HOLD_TIMER_EXP, 0); - continue; - } + return 1; +} - if (time_now > peer->keepalive_time && !peer->outbuf->packet.header.len) - bgp_send_keepalive(peer); - } - else if (peer->state == Idle) - { - if (time_now > peer->retry_time) - bgp_connect(peer); - } - else if (time_now > peer->state_time + BGP_STATE_TIME) +/* process bgp timers only */ +void bgp_process_peers_timers() +{ + int i; + + if (!bgp_configured) + return; + + for (i = 0; i < BGP_NUM_PEERS; i++) + { + struct bgp_peer *peer = &bgp_peers[i]; + + if (peer->state == Disabled) + continue; + + bgp_process_timers(peer); + } +} + +static void bgp_process_timers(struct bgp_peer *peer) +{ + if (peer->state == Established) + { + if (time_now > peer->expire_time) { - LOG(1, 0, 0, "%s timer expired for BGP peer %s\n", - bgp_state_str(peer->state), peer->name); + LOG(1, 0, 0, "No message from BGP peer %s in %ds\n", + peer->name, peer->hold); - bgp_restart(peer); + bgp_send_notification(peer, BGP_ERR_HOLD_TIMER_EXP, 0); + return; } + + if (time_now > peer->keepalive_time && !peer->outbuf->packet.header.len) + bgp_send_keepalive(peer); + } + else if (peer->state == Idle) + { + if (time_now > peer->retry_time) + bgp_connect(peer); } + else if (time_now > peer->state_time + BGP_STATE_TIME) + { + LOG(1, 0, 0, "%s timer expired for BGP peer %s\n", + bgp_state_str(peer->state), peer->name); - return 1; + bgp_restart(peer); + } } static void bgp_free_routes(struct bgp_route_list *routes) @@ -903,6 +918,7 @@ static int bgp_connect(struct bgp_peer *peer) { static int bgp_port = 0; struct sockaddr_in addr; + struct sockaddr_in source_addr; struct epoll_event ev; if (!bgp_port) @@ -934,6 +950,19 @@ static int bgp_connect(struct bgp_peer *peer) /* set to non-blocking */ fcntl(peer->sock, F_SETFL, fcntl(peer->sock, F_GETFL, 0) | O_NONBLOCK); + /* set source address */ + memset(&source_addr, 0, sizeof(source_addr)); + source_addr.sin_family = AF_INET; + source_addr.sin_addr.s_addr = peer->source_addr; /* defaults to INADDR_ANY */ + if (bind(peer->sock, (struct sockaddr *) &source_addr, sizeof(source_addr)) < 0) + { + LOG(1, 0, 0, "Can't set source address to %s: %s\n", + inet_ntoa(source_addr.sin_addr), strerror(errno)); + + bgp_set_retry(peer); + return 0; + } + /* try connect */ memset(&addr, 0, sizeof(addr)); addr.sin_family = AF_INET; @@ -967,8 +996,6 @@ 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); } @@ -992,8 +1019,6 @@ 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); } @@ -1187,7 +1212,7 @@ static int bgp_handle_input(struct bgp_peer *peer) param_offset < data.opt_len; param_offset += 2 + param->len) { - param = (struct bgp_opt_param *)(&data.opt_params + param_offset); + param = (struct bgp_opt_param *)((char *)&data.opt_params + param_offset); /* sensible check */ if (data.opt_len - param_offset < 2 @@ -1212,11 +1237,8 @@ static int bgp_handle_input(struct bgp_peer *peer) capabilities_len = param->len; capabilities = (char *)¶m->value; - } - /* look for BGP multiprotocol capability */ - if (capabilities) - { + /* look for BGP multiprotocol capability */ for (capability_offset = 0; capability_offset < capabilities_len; capability_offset += 2 + capability->len) @@ -1241,29 +1263,34 @@ static int bgp_handle_input(struct bgp_peer *peer) LOG(4, 0, 0, "Unsupported Capability code %d from BGP peer %s\n", capability->code, peer->name); - bgp_send_notification_full(peer, BGP_ERR_OPEN, BGP_ERR_OPN_UNSUP_CAP, - (char *)capability, 2 + capability->len); /* we don't terminate, still; we just jump to the next one */ continue; } 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); - bgp_send_notification_full(peer, BGP_ERR_OPEN, BGP_ERR_OPN_UNSUP_CAP, - (char *)capability, 2 + capability->len); /* we don't terminate, still; we just jump to the next one */ continue; } - peer->handle_ipv6_routes = 1; + /* yes it can! */ + peer->mp_handling = HandleIPv6Routes; } } + if (peer->mp_handling != HandleIPv6Routes) + { + peer->mp_handling = DoesntHandleIPv6Routes; + if (config->ipv6_prefix.s6_addr[0]) + LOG(1, 0, 0, "Warning: BGP peer %s doesn't handle IPv6 prefixes updates\n", + peer->name); + } + /* next transition requires an exchange of keepalives */ bgp_send_keepalive(peer); } @@ -1294,7 +1321,16 @@ static int bgp_handle_input(struct bgp_peer *peer) if (notification->error_code == BGP_ERR_CEASE) { LOG(4, 0, 0, "BGP peer %s sent CEASE\n", peer->name); - bgp_restart(peer); + bgp_set_retry(peer); + return 0; + } + + if (notification->error_code == BGP_ERR_OPEN + && 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_set_retry(peer); return 0; } @@ -1305,7 +1341,7 @@ static int bgp_handle_input(struct bgp_peer *peer) 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; } @@ -1339,7 +1375,7 @@ 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); @@ -1352,22 +1388,35 @@ static int bgp_send_open(struct bgp_peer *peer) data.version = BGP_VERSION; data.as = htons(our_as); data.hold_time = htons(peer->hold); - data.identifier = my_address; + /* use the source IP we use as identifier, if available */ + if (peer->source_addr != INADDR_ANY) + data.identifier = peer->source_addr; + else + 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 (config->ipv6_prefix.s6_addr[0] + && (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; @@ -1537,9 +1586,9 @@ static int bgp_send_update(struct bgp_peer *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; + uint16_t unreach_len = 0; + char *unreach_len_pos; uint8_t reach_len; uint16_t len = sizeof(peer->outbuf->packet.header); struct bgp_route6_list *have = peer->routes6; @@ -1562,24 +1611,24 @@ static int bgp_send_update6(struct bgp_peer *peer) 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); + /* insert non-MP unfeasible routes length */ + memcpy(data, &unreach_len, sizeof(unreach_len)); + /* skip over it and attr_len too; it will be filled when known */ + data += sizeof(unreach_len) + sizeof(attr_len); + len += sizeof(unreach_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; + attr_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; + unreach_len_pos = data + 2; data += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE; - len += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE; + attr_len += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE; peer->update_routes6 = 0; /* tentatively clear */ @@ -1601,8 +1650,8 @@ static int bgp_send_update6(struct bgp_peer *peer) s = BGP_IP_PREFIX_SIZE(tmp->dest); memcpy(data, &tmp->dest, s); data += s; - unf_len += s; - len += s; + unreach_len += s; + attr_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), @@ -1644,13 +1693,22 @@ static int bgp_send_update6(struct bgp_peer *peer) peer->update_routes6 = 1; /* more to do */ /* anything changed? */ - if (!(unf_len || add)) + if (!(unreach_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 (unreach_len) + { + /* go back and insert MP unreach_len */ + unreach_len += sizeof(struct bgp_attr_mp_unreach_nlri_partial); + unreach_len = htons(unreach_len); + memcpy(unreach_len_pos, &unreach_len, sizeof(unreach_len)); + } + else + { + /* we can remove this attribute, then */ + data -= BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE; + attr_len -= BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE; + } if (add) { @@ -1672,22 +1730,25 @@ static int bgp_send_update6(struct bgp_peer *peer) 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; + data[2] = sizeof(struct bgp_attr_mp_reach_nlri_partial) + reach_len; + data += BGP_PATH_ATTR_MP_REACH_NLRI_PARTIAL_SIZE; + attr_len += BGP_PATH_ATTR_MP_REACH_NLRI_PARTIAL_SIZE; memcpy(data, &add->dest, reach_len); data += reach_len; - len += reach_len; + attr_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); } + /* update len with attributes we added */ + len += attr_len; + /* go back and insert attr_len */ - attr_len = htons(len - 4); - memcpy(&peer->outbuf->packet.data + 2, &attr_len, sizeof(attr_len)); + attr_len = htons(attr_len); + memcpy((char *)&peer->outbuf->packet.data + 2, &attr_len, sizeof(attr_len)); peer->outbuf->packet.header.len = htons(len); peer->outbuf->done = 0; @@ -1698,12 +1759,6 @@ static int bgp_send_update6(struct bgp_peer *peer) /* send/buffer NOTIFICATION message */ static int bgp_send_notification(struct bgp_peer *peer, uint8_t code, uint8_t subcode) -{ - return bgp_send_notification_full(peer, code, subcode, NULL, 0); -} - -static int bgp_send_notification_full(struct bgp_peer *peer, uint8_t code, - uint8_t subcode, char *notification_data, uint16_t data_len) { struct bgp_data_notification data; uint16_t len = 0; @@ -1714,9 +1769,6 @@ static int bgp_send_notification_full(struct bgp_peer *peer, uint8_t code, data.error_subcode = subcode; len += sizeof(data.error_code); - memcpy(data.data, notification_data, data_len); - len += data_len; - memset(peer->outbuf->packet.header.marker, 0xff, sizeof(peer->outbuf->packet.header.marker));