diff options
| -rw-r--r-- | proto/bgp/bgp.c | 4 | ||||
| -rw-r--r-- | proto/bgp/bgp.h | 5 | ||||
| -rw-r--r-- | proto/bgp/packets.c | 49 |
3 files changed, 47 insertions, 11 deletions
diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c index d1b7dee..558b1e8 100644 --- a/proto/bgp/bgp.c +++ b/proto/bgp/bgp.c @@ -368,6 +368,10 @@ bgp_conn_enter_idle_state(struct bgp_conn *conn) static void bgp_send_open(struct bgp_conn *conn) { + conn->start_state = conn->bgp->start_state; + conn->want_as4_support = conn->bgp->cf->enable_as4 && (conn->start_state != BSS_CONNECT_NOCAP); + conn->peer_as4_support = 0; // Default value, possibly changed by receiving capability. + DBG("BGP: Sending open\n"); conn->sk->rx_hook = bgp_rx; conn->sk->tx_hook = bgp_tx; diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h index 5c180cc..b706caf 100644 --- a/proto/bgp/bgp.h +++ b/proto/bgp/bgp.h @@ -51,9 +51,10 @@ struct bgp_conn { int packets_to_send; /* Bitmap of packet types to be sent */ int notify_code, notify_subcode, notify_size; byte *notify_data; - int error_flag; /* Error state, ignore all input */ u32 advertised_as; /* Temporary value for AS number received */ - int as4_support; /* Peer supports 4B AS numbers [RFC4893] */ + int start_state; /* protocol start_state snapshot when connection established */ + int want_as4_support; /* Connection tries to establish AS4 session */ + int peer_as4_support; /* Peer supports 4B AS numbers [RFC4893] */ unsigned hold_time, keepalive_time; /* Times calculated from my and neighbor's requirements */ }; diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c index 4e42d90..27c0755 100644 --- a/proto/bgp/packets.c +++ b/proto/bgp/packets.c @@ -69,13 +69,21 @@ bgp_create_open(struct bgp_conn *conn, byte *buf) put_u16(buf+1, (p->local_as < 0xFFFF) ? p->local_as : AS_TRANS); put_u16(buf+3, p->cf->hold_time); put_u32(buf+5, p->local_id); + + if (conn->start_state == BSS_CONNECT_NOCAP) + { + BGP_TRACE(D_PACKETS, "Skipping capabilities"); + buf[9] = 0; + return buf + 10; + } + /* Skipped 3 B for length field and Capabilities parameter header */ cap = buf + 12; #ifdef IPV6 cap = bgp_put_cap_ipv6(conn, cap); #endif - if (p->cf->enable_as4) + if (conn->want_as4_support) cap = bgp_put_cap_as4(conn, cap); cap_len = cap - buf - 12; @@ -418,9 +426,8 @@ bgp_parse_capabilities(struct bgp_conn *conn, byte *opt, int len) case 65: if (cl != 4) goto err; - conn->as4_support = 1; - - if (p->cf->enable_as4) + conn->peer_as4_support = 1; + if (conn->want_as4_support) conn->advertised_as = get_u32(opt + 2); break; @@ -501,7 +508,6 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, int len) id = get_u32(pkt+24); BGP_TRACE(D_PACKETS, "Got OPEN(as=%d,hold=%d,id=%08x)", conn->advertised_as, hold, id); - conn->as4_support = 0; // Default value, possibly changed by capability. if (bgp_parse_options(conn, pkt+29, pkt[28])) return; @@ -548,8 +554,8 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, int len) conn->hold_time = MIN(hold, p->cf->hold_time); conn->keepalive_time = p->cf->keepalive_time ? : conn->hold_time / 3; p->remote_id = id; - p->as4_session = p->cf->enable_as4 && conn->as4_support; - + p->as4_session = conn->want_as4_support && conn->peer_as4_support; + DBG("BGP: Hold timer set to %d, keepalive to %d, AS to %d, ID to %x, AS4 session to %d\n", conn->hold_time, conn->keepalive_time, p->remote_as, p->remote_id, p->as4_session); bgp_schedule_packet(conn, PKT_KEEPALIVE); @@ -820,7 +826,15 @@ static struct { { 3, 11, "Malformed AS_PATH" }, { 4, 0, "Hold timer expired" }, { 5, 0, "Finite state machine error" }, - { 6, 0, "Cease" } + { 6, 0, "Cease" }, /* Subcodes are according to [RFC4486] */ + { 6, 1, "Maximum number of prefixes reached" }, + { 6, 2, "Administrative shutdown" }, + { 6, 3, "Peer de-configured" }, + { 6, 4, "Administrative reset" }, + { 6, 5, "Connection rejected" }, + { 6, 6, "Other configuration change" }, + { 6, 7, "Connection collision resolution" }, + { 6, 8, "Out of Resources" } }; /** @@ -875,6 +889,7 @@ bgp_log_error(struct bgp_proto *p, char *msg, unsigned code, unsigned subcode, b static void bgp_rx_notification(struct bgp_conn *conn, byte *pkt, int len) { + struct bgp_proto *p = conn->bgp; if (len < 21) { bgp_error(conn, 1, 2, pkt+16, 2); @@ -883,9 +898,25 @@ bgp_rx_notification(struct bgp_conn *conn, byte *pkt, int len) unsigned code = pkt[19]; unsigned subcode = pkt[20]; + int delay = 1; + +#ifndef IPV6 + if ((code == 2) && ((subcode == 4) || (subcode == 7))) + { + /* Error related to capability: + * 4 - Peer does not support capabilities at all. + * 7 - Peer request some capability. Strange unless it is IPv6 only peer. + * We try connect without capabilities + */ + BGP_TRACE(D_EVENTS, "Capability related error received, capabilities disabled"); + conn->bgp->start_state = BSS_CONNECT_NOCAP; + delay = 0; + } +#endif + bgp_log_error(conn->bgp, "Received error notification", code, subcode, pkt+21, len-21); bgp_store_error(conn->bgp, conn, BE_BGP_RX, (code << 16) | subcode); - bgp_update_startup_delay(conn->bgp, conn, code, subcode); + if (delay) bgp_update_startup_delay(conn->bgp, conn, code, subcode); bgp_conn_enter_close_state(conn); bgp_schedule_packet(conn, PKT_SCHEDULE_CLOSE); } |