BGP: Extended messages support

Implements draft-ietf-idr-bgp-extended-messages-10, for now
undocumented and with temporary private capability number.
This commit is contained in:
Ondrej Zajicek 2015-07-18 13:38:21 +02:00
parent ab4da3423d
commit 06e0d1b692
5 changed files with 54 additions and 15 deletions

View file

@ -1571,7 +1571,7 @@ RFC 4271<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4271.txt">
It also supports the community attributes
(RFC 1997<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc1997.txt">),
capability negotiation
(RFC 3392<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc3392.txt">),
(RFC 5492<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc5492.txt">),
MD5 password authentication
(RFC 2385<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc2385.txt">),
extended communities

View file

@ -569,6 +569,7 @@ bgp_send_open(struct bgp_conn *conn)
conn->peer_gr_time = 0;
conn->peer_gr_flags = 0;
conn->peer_gr_aflags = 0;
conn->peer_ext_messages_support = 0;
DBG("BGP: Sending open\n");
conn->sk->rx_hook = bgp_rx;
@ -733,8 +734,8 @@ bgp_connect(struct bgp_proto *p) /* Enter Connect state and start establishing c
s->dport = p->cf->remote_port;
s->iface = p->neigh ? p->neigh->iface : NULL;
s->ttl = p->cf->ttl_security ? 255 : hops;
s->rbsize = BGP_RX_BUFFER_SIZE;
s->tbsize = BGP_TX_BUFFER_SIZE;
s->rbsize = p->cf->enable_extended_messages ? BGP_RX_BUFFER_EXT_SIZE : BGP_RX_BUFFER_SIZE;
s->tbsize = p->cf->enable_extended_messages ? BGP_TX_BUFFER_EXT_SIZE : BGP_TX_BUFFER_SIZE;
s->tos = IP_PREC_INTERNET_CONTROL;
s->password = p->cf->password;
s->tx_hook = bgp_connected;
@ -843,6 +844,13 @@ bgp_incoming_connection(sock *sk, int dummy UNUSED)
if (sk_set_min_ttl(sk, 256 - hops) < 0)
goto err;
if (p->cf->enable_extended_messages)
{
sk->rbsize = BGP_RX_BUFFER_EXT_SIZE;
sk->tbsize = BGP_TX_BUFFER_EXT_SIZE;
sk_reallocate(sk);
}
bgp_setup_conn(p, &p->incoming_conn);
bgp_setup_sk(&p->incoming_conn, sk);
bgp_send_open(&p->incoming_conn);
@ -1518,21 +1526,23 @@ bgp_show_proto_info(struct proto *P)
else if (P->proto_state == PS_UP)
{
cli_msg(-1006, " Neighbor ID: %R", p->remote_id);
cli_msg(-1006, " Neighbor caps: %s%s%s%s%s%s",
cli_msg(-1006, " Neighbor caps: %s%s%s%s%s%s%s",
c->peer_refresh_support ? " refresh" : "",
c->peer_enhanced_refresh_support ? " enhanced-refresh" : "",
c->peer_gr_able ? " restart-able" : (c->peer_gr_aware ? " restart-aware" : ""),
c->peer_as4_support ? " AS4" : "",
(c->peer_add_path & ADD_PATH_RX) ? " add-path-rx" : "",
(c->peer_add_path & ADD_PATH_TX) ? " add-path-tx" : "");
cli_msg(-1006, " Session: %s%s%s%s%s%s%s",
(c->peer_add_path & ADD_PATH_TX) ? " add-path-tx" : "",
c->peer_ext_messages_support ? " ext-messages" : "");
cli_msg(-1006, " Session: %s%s%s%s%s%s%s%s",
p->is_internal ? "internal" : "external",
p->cf->multihop ? " multihop" : "",
p->rr_client ? " route-reflector" : "",
p->rs_client ? " route-server" : "",
p->as4_session ? " AS4" : "",
p->add_path_rx ? " add-path-rx" : "",
p->add_path_tx ? " add-path-tx" : "");
p->add_path_tx ? " add-path-tx" : "",
p->ext_messages ? " ext-messages" : "");
cli_msg(-1006, " Source address: %I", p->source_addr);
if (P->cf->in_limit)
cli_msg(-1006, " Route limit: %d/%d",

View file

@ -40,6 +40,7 @@ struct bgp_config {
int capabilities; /* Enable capability handshake [RFC3392] */
int enable_refresh; /* Enable local support for route refresh [RFC2918] */
int enable_as4; /* Enable local support for 4B AS numbers [RFC4893] */
int enable_extended_messages; /* Enable local support for extended messages [draft] */
u32 rr_cluster_id; /* Route reflector cluster ID, if different from local ID */
int rr_client; /* Whether neighbor is RR client of me */
int rs_client; /* Whether neighbor is RS client of me */
@ -109,6 +110,7 @@ struct bgp_conn {
u16 peer_gr_time;
u8 peer_gr_flags;
u8 peer_gr_aflags;
u8 peer_ext_messages_support; /* Peer supports extended message length [draft] */
unsigned hold_time, keepalive_time; /* Times calculated from my and neighbor's requirements */
};
@ -121,6 +123,7 @@ struct bgp_proto {
u8 as4_session; /* Session uses 4B AS numbers in AS_PATH (both sides support it) */
u8 add_path_rx; /* Session expects receive of ADD-PATH extended NLRI */
u8 add_path_tx; /* Session expects transmit of ADD-PATH extended NLRI */
u8 ext_messages; /* Session allows to use extended messages (both sides support it) */
u32 local_id; /* BGP identifier of this router */
u32 remote_id; /* BGP identifier of the neighbor */
u32 rr_cluster_id; /* Route reflector cluster ID */
@ -180,9 +183,15 @@ struct bgp_bucket {
#define BGP_PORT 179
#define BGP_VERSION 4
#define BGP_HEADER_LENGTH 19
#define BGP_MAX_PACKET_LENGTH 4096
#define BGP_MAX_MESSAGE_LENGTH 4096
#define BGP_MAX_EXT_MSG_LENGTH 65535
#define BGP_RX_BUFFER_SIZE 4096
#define BGP_TX_BUFFER_SIZE BGP_MAX_PACKET_LENGTH
#define BGP_TX_BUFFER_SIZE 4096
#define BGP_RX_BUFFER_EXT_SIZE 65535
#define BGP_TX_BUFFER_EXT_SIZE 65535
static inline int bgp_max_packet_length(struct bgp_proto *p)
{ return p->ext_messages ? BGP_MAX_EXT_MSG_LENGTH : BGP_MAX_MESSAGE_LENGTH; }
extern struct linpool *bgp_linpool;

View file

@ -27,7 +27,7 @@ CF_KEYWORDS(BGP, LOCAL, NEIGHBOR, AS, HOLD, TIME, CONNECT, RETRY,
INTERPRET, COMMUNITIES, BGP_ORIGINATOR_ID, BGP_CLUSTER_LIST, IGP,
TABLE, GATEWAY, DIRECT, RECURSIVE, MED, TTL, SECURITY, DETERMINISTIC,
SECONDARY, ALLOW, BFD, ADD, PATHS, RX, TX, GRACEFUL, RESTART, AWARE,
CHECK, LINK, PORT)
CHECK, LINK, PORT, EXTENDED, MESSAGES)
CF_GRAMMAR
@ -108,6 +108,7 @@ bgp_proto:
| bgp_proto DISABLE AFTER ERROR bool ';' { BGP_CFG->disable_after_error = $5; }
| bgp_proto ENABLE ROUTE REFRESH bool ';' { BGP_CFG->enable_refresh = $5; }
| bgp_proto ENABLE AS4 bool ';' { BGP_CFG->enable_as4 = $4; }
| bgp_proto ENABLE EXTENDED MESSAGES bool ';' { BGP_CFG->enable_extended_messages = $5; }
| bgp_proto CAPABILITIES bool ';' { BGP_CFG->capabilities = $3; }
| bgp_proto ADVERTISE IPV4 bool ';' { BGP_CFG->advertise_ipv4 = $4; }
| bgp_proto PASSWORD text ';' { BGP_CFG->password = $3; }

View file

@ -84,7 +84,7 @@ mrt_put_bgp4_hdr(byte *buf, struct bgp_conn *conn, int as4)
static void
mrt_dump_bgp_packet(struct bgp_conn *conn, byte *pkt, unsigned len)
{
byte buf[BGP_MAX_PACKET_LENGTH + 128];
byte *buf = alloca(128+len); /* 128 is enough for MRT headers */
byte *bp = buf + MRTDUMP_HDR_LENGTH;
int as4 = conn->bgp->as4_session;
@ -223,6 +223,14 @@ bgp_put_cap_err(struct bgp_proto *p UNUSED, byte *buf)
return buf;
}
static byte *
bgp_put_cap_ext_msg(struct bgp_proto *p UNUSED, byte *buf)
{
*buf++ = 230; /* Capability TBD: Support for extended messages */
*buf++ = 0; /* Capability data length */
return buf;
}
static byte *
bgp_create_open(struct bgp_conn *conn, byte *buf)
@ -274,6 +282,9 @@ bgp_create_open(struct bgp_conn *conn, byte *buf)
if (p->cf->enable_refresh)
cap = bgp_put_cap_err(p, cap);
if (p->cf->enable_extended_messages)
cap = bgp_put_cap_ext_msg(p, cap);
cap_len = cap - buf - 12;
if (cap_len > 0)
{
@ -342,7 +353,7 @@ bgp_create_update(struct bgp_conn *conn, byte *buf)
{
struct bgp_proto *p = conn->bgp;
struct bgp_bucket *buck;
int remains = BGP_MAX_PACKET_LENGTH - BGP_HEADER_LENGTH - 4;
int remains = bgp_max_packet_length(p) - BGP_HEADER_LENGTH - 4;
byte *w;
int wd_size = 0;
int r_size = 0;
@ -428,7 +439,7 @@ bgp_create_update(struct bgp_conn *conn, byte *buf)
struct bgp_proto *p = conn->bgp;
struct bgp_bucket *buck;
int size, second, rem_stored;
int remains = BGP_MAX_PACKET_LENGTH - BGP_HEADER_LENGTH - 4;
int remains = bgp_max_packet_length(p) - BGP_HEADER_LENGTH - 4;
byte *w, *w_stored, *tmp, *tstart;
ip_addr *ipp, ip, ip_ll;
ea_list *ea;
@ -856,6 +867,12 @@ bgp_parse_capabilities(struct bgp_conn *conn, byte *opt, int len)
conn->peer_enhanced_refresh_support = 1;
break;
case 230: /* Extended message length capability, draft, cap number TBD */
if (cl != 0)
goto err;
conn->peer_ext_messages_support = 1;
break;
/* We can safely ignore all other capabilities */
}
len -= 2 + cl;
@ -1019,6 +1036,7 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, int len)
p->add_path_rx = (p->cf->add_path & ADD_PATH_RX) && (conn->peer_add_path & ADD_PATH_TX);
p->add_path_tx = (p->cf->add_path & ADD_PATH_TX) && (conn->peer_add_path & ADD_PATH_RX);
p->gr_ready = p->cf->gr_mode && conn->peer_gr_able;
p->ext_messages = p->cf->enable_extended_messages && conn->peer_ext_messages_support;
if (p->add_path_tx)
p->p.accept_ra_types = RA_ANY;
@ -1418,7 +1436,7 @@ static struct {
{ 2, 4, "Unsupported optional parameter" },
{ 2, 5, "Authentication failure" },
{ 2, 6, "Unacceptable hold time" },
{ 2, 7, "Required capability missing" }, /* [RFC3392] */
{ 2, 7, "Required capability missing" }, /* [RFC5492] */
{ 2, 8, "No supported AFI/SAFI" }, /* This error msg is nonstandard */
{ 3, 0, "Invalid UPDATE message" },
{ 3, 1, "Malformed attribute list" },
@ -1666,6 +1684,7 @@ int
bgp_rx(sock *sk, int size)
{
struct bgp_conn *conn = sk->data;
struct bgp_proto *p = conn->bgp;
byte *pkt_start = sk->rbuf;
byte *end = pkt_start + size;
unsigned i, len;
@ -1682,7 +1701,7 @@ bgp_rx(sock *sk, int size)
break;
}
len = get_u16(pkt_start+16);
if (len < BGP_HEADER_LENGTH || len > BGP_MAX_PACKET_LENGTH)
if (len < BGP_HEADER_LENGTH || len > bgp_max_packet_length(p))
{
bgp_error(conn, 1, 2, pkt_start+16, 2);
break;