From: Benjamin Cama Date: Tue, 19 Jul 2011 13:15:40 +0000 (+0200) Subject: Add Optional Parameter and Capability handling. X-Git-Tag: debian/2.2.1-1fdn1~1^2^2~21 X-Git-Url: http://git.sameswireless.fr/l2tpns.git/commitdiff_plain/1b8cb12cb4e85703102de8e464c66603e1766c23?ds=sidebyside Add Optional Parameter and Capability handling. Optional Parameters is defined in RFC4271 and Capability advertisement in RFC3392. For now, we only hande them upon receiving an OPEN message. Signed-off-by: Benjamin Cama --- diff --git a/bgp.c b/bgp.c index 6a868fa..d7701be 100644 --- a/bgp.c +++ b/bgp.c @@ -902,6 +902,11 @@ static int bgp_handle_input(struct bgp_peer *peer) struct bgp_data_open data; int hold; int i; + off_t param_offset, capability_offset; + struct bgp_opt_param *param; + uint8_t capabilities_len; + char *capabilities = NULL; + struct bgp_capability *capability; for (i = 0; i < sizeof(p->header.marker); i++) { @@ -964,10 +969,70 @@ static int bgp_handle_input(struct bgp_peer *peer) if (peer->keepalive * 3 > peer->hold) peer->keepalive = peer->hold / 3; + /* check for optional parameters */ + /* 2 is for the size of type + len (both uint8_t) */ + for (param_offset = 0; + param_offset < data.opt_len; + param_offset += 2 + param->len) + { + param = (struct bgp_opt_param *)(&data.opt_params + param_offset); + + /* sensible check */ + if (data.opt_len - param_offset < 2 + || param->len > data.opt_len - param_offset - 2) { + LOG(1, 0, 0, "Malformed Optional Parameter list from BGP peer %s\n", + peer->name); + + bgp_send_notification(peer, BGP_ERR_OPEN, BGP_ERR_UNSPEC); + return 0; + } + + /* we know only one parameter type */ + if (param->type != BGP_CAPABILITY_PARAM_TYPE) { + LOG(1, 0, 0, "Unsupported Optional Parameter type %d from BGP peer %s\n", + param->type, peer->name); + + bgp_send_notification(peer, BGP_ERR_OPEN, BGP_ERR_OPN_UNSUP_PARAM); + return 0; + } + + capabilities_len = param->len; + capabilities = (char *)¶m->value; + } + + /* look for BGP multiprotocol capability */ + if (capabilities) + { + for (capability_offset = 0; + capability_offset < capabilities_len; + capability_offset += 2 + capability->len) + { + capability = (struct bgp_capability *)(capabilities + capability_offset); + + /* sensible check */ + if (capabilities_len - capability_offset < 2 + || capability->len > capabilities_len - capability_offset - 2) { + LOG(1, 0, 0, "Malformed Capabilities list from BGP peer %s\n", + peer->name); + + bgp_send_notification(peer, BGP_ERR_OPEN, BGP_ERR_UNSPEC); + return 0; + } + + /* we only know one capability code */ + if (capability->code != XXX) { + LOG(4, 0, 0, "Unsupported Capability code %d from BGP peer %s\n", + capability->code, peer->name); + + /* TODO: send _which_ capability is unsupported */ + bgp_send_notification(peer, BGP_ERR_OPEN, BGP_ERR_OPN_UNSUP_CAP); + /* we don't terminate, still; we just jump to the next one */ + } + } + } + /* next transition requires an exchange of keepalives */ bgp_send_keepalive(peer); - - /* FIXME: may need to check for optional params */ } break; diff --git a/bgp.h b/bgp.h index 0a2e59c..beb68f9 100644 --- a/bgp.h +++ b/bgp.h @@ -43,6 +43,21 @@ struct bgp_data_open { char opt_params[sizeof(((struct bgp_packet *)0)->data) - BGP_DATA_OPEN_SIZE]; /* variable */ } __attribute__ ((packed)); +struct bgp_opt_param { + uint8_t type; + uint8_t len; +#define BGP_MAX_OPT_PARAM_SIZE 256 + char value[BGP_MAX_OPT_PARAM_SIZE]; +} __attribute__ ((packed)); + +#define BGP_CAPABILITY_PARAM_TYPE 2 +struct bgp_capability { + uint8_t code; + uint8_t len; +#define BGP_MAX_CAPABILITY_SIZE 256 + char value[BGP_MAX_CAPABILITY_SIZE]; +} __attribute__ ((packed)); + struct bgp_ip_prefix { uint8_t len; uint32_t prefix; /* variable */ @@ -101,6 +116,7 @@ struct bgp_data_notification { } __attribute__ ((packed)); /* bgp_data_notification.error_code, .error_subcode */ +#define BGP_ERR_UNSPEC 0 #define BGP_ERR_HEADER 1 # define BGP_ERR_HDR_NOT_SYNC 1 # define BGP_ERR_HDR_BAD_LEN 2 @@ -112,6 +128,7 @@ struct bgp_data_notification { # define BGP_ERR_OPN_UNSUP_PARAM 4 # define BGP_ERR_OPN_AUTH_FAILURE 5 # define BGP_ERR_OPN_HOLD_TIME 6 +# define BGP_ERR_OPN_UNSUP_CAP 7 #define BGP_ERR_UPDATE 3 # define BGP_ERR_UPD_BAD_ATTR_LIST 1 # define BGP_ERR_UPD_UNKN_WK_ATTR 2