From e86393ea90d7ca3d84ecdd2e749a2e1372c60827 Mon Sep 17 00:00:00 2001 From: Benjamin Cama Date: Wed, 20 Jul 2011 17:46:21 +0200 Subject: [PATCH] Better handle IPv6 routes advertisement (non-)support. Don't try to enable multiprotocol BGP when the peer says it can't. Signed-off-by: Benjamin Cama --- bgp.c | 49 ++++++++++++++++++++++++++++++++----------------- bgp.h | 8 +++++++- 2 files changed, 39 insertions(+), 18 deletions(-) diff --git a/bgp.c b/bgp.c index d9c5818..7de3d3f 100644 --- a/bgp.c +++ b/bgp.c @@ -295,6 +295,8 @@ 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"); @@ -967,8 +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); } @@ -992,8 +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); } @@ -1260,7 +1258,7 @@ static int bgp_handle_input(struct bgp_peer *peer) continue; } - peer->handle_ipv6_routes = 1; + peer->mp_handling = HandleIPv6Routes; } } @@ -1298,6 +1296,15 @@ static int bgp_handle_input(struct bgp_peer *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_restart(peer); + return 0; + } + if (notification->error_code == BGP_ERR_OPEN && notification->error_subcode == BGP_ERR_OPN_UNSUP_CAP) { @@ -1305,7 +1312,7 @@ 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; } @@ -1354,20 +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; diff --git a/bgp.h b/bgp.h index 6dbfbf8..8702838 100644 --- a/bgp.h +++ b/bgp.h @@ -209,6 +209,12 @@ struct bgp_buf { size_t done; /* bytes sent/recvd */ }; +enum bgp_mp_handling { + HandleIPv6Routes, + DoesntHandleIPv6Routes, + HandlingUnknown, +}; + /* state */ struct bgp_peer { char name[32]; /* peer name */ @@ -237,7 +243,7 @@ struct bgp_peer { int path_attr_len_without_nexthop; /* length of path attrs without NEXT_HOP */ uint32_t events; /* events to poll */ struct event_data edata; /* poll data */ - int handle_ipv6_routes; /* can handle IPv6 routes advertisements */ + enum bgp_mp_handling mp_handling; /* how it handles IPv6 routes advertisements */ int update_routes6; /* UPDATE required for IPv6 routes */ struct bgp_route6_list *routes6; /* IPv6 routes known by this peer */ char mp_reach_nlri_partial[BGP_PATH_ATTR_MP_REACH_NLRI_PARTIAL_SIZE]; -- 2.20.1