From 72a6ef11fe6589d0f4d5158c207ff8a0669becc3 Mon Sep 17 00:00:00 2001 From: Martin Mares Date: Tue, 21 Mar 2000 15:53:50 +0000 Subject: Construction of BGP packets. --- proto/bgp/Makefile | 2 +- proto/bgp/bgp.c | 14 ++---- proto/bgp/bgp.h | 18 +++++-- proto/bgp/packets.c | 141 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 160 insertions(+), 15 deletions(-) (limited to 'proto') diff --git a/proto/bgp/Makefile b/proto/bgp/Makefile index 0f0ba27..a634cf0 100644 --- a/proto/bgp/Makefile +++ b/proto/bgp/Makefile @@ -1,4 +1,4 @@ -source=bgp.c attrs.c +source=bgp.c attrs.c packets.c root-rel=../../ dir-name=proto/bgp diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c index 40915a4..c52e8bd 100644 --- a/proto/bgp/bgp.c +++ b/proto/bgp/bgp.c @@ -78,21 +78,13 @@ bgp_start_timer(timer *t, int value) tm_start(t, value); } -static int -bgp_rx(sock *sk, int size) -{ - DBG("BGP: Got %d bytes\n", size); - - return 1; /* Start from the beginning */ -} - static void bgp_send_open(struct bgp_conn *conn) { DBG("BGP: Sending open\n"); conn->sk->rx_hook = bgp_rx; tm_stop(conn->connect_retry_timer); - /* FIXME */ + bgp_schedule_packet(conn, PKT_OPEN); conn->state = BS_OPENSENT; } @@ -174,14 +166,14 @@ bgp_setup_sk(struct bgp_proto *p, struct bgp_conn *conn, sock *s) s->data = conn; s->ttl = p->cf->multihop ? : 1; s->rbsize = BGP_RX_BUFFER_SIZE; -#if 0 + s->tbsize = BGP_TX_BUFFER_SIZE; s->tx_hook = bgp_tx; -#endif s->err_hook = bgp_err; s->tos = IP_PREC_INTERNET_CONTROL; conn->bgp = p; conn->sk = s; + conn->packets_to_send = 0; t = conn->connect_retry_timer = tm_new(p->p.pool); t->hook = bgp_connect_timeout; diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h index 8e2e8df..3ddf619 100644 --- a/proto/bgp/bgp.h +++ b/proto/bgp/bgp.h @@ -22,10 +22,13 @@ struct bgp_config { struct bgp_conn { struct bgp_proto *bgp; struct birdsock *sk; - int state; /* State of connection state machine */ + unsigned int state; /* State of connection state machine */ struct timer *connect_retry_timer; struct timer *hold_timer; struct timer *keepalive_timer; + unsigned int packets_to_send; /* Bitmap of packet types to be sent */ + unsigned int notify_code, notify_subcode, notify_arg, notify_arg_size; + unsigned int error_flag; /* Error state, ignore all input */ }; struct bgp_proto { @@ -42,8 +45,12 @@ struct bgp_proto { struct object_lock *lock; /* Lock for neighbor connection */ }; -#define BGP_PORT 179 -#define BGP_RX_BUFFER_SIZE 4096 +#define BGP_PORT 179 +#define BGP_VERSION 4 +#define BGP_HEADER_LENGTH 19 +#define BGP_MAX_PACKET_LENGTH 4096 +#define BGP_RX_BUFFER_SIZE 4096 +#define BGP_TX_BUFFER_SIZE BGP_MAX_PACKET_LENGTH void bgp_check(struct bgp_config *c); @@ -51,12 +58,17 @@ void bgp_check(struct bgp_config *c); /* packets.c */ +void bgp_schedule_packet(struct bgp_conn *conn, int type); +void bgp_tx(struct birdsock *sk); +int bgp_rx(struct birdsock *sk, int size); + /* Packet types */ #define PKT_OPEN 0x01 #define PKT_UPDATE 0x02 #define PKT_NOTIFICATION 0x03 #define PKT_KEEPALIVE 0x04 +#define PKT_SCHEDULE_CLOSE 0x1f /* Used internally to schedule socket close */ /* Attributes */ diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c index a5f52b8..b3b25f4 100644 --- a/proto/bgp/packets.c +++ b/proto/bgp/packets.c @@ -6,10 +6,151 @@ * Can be freely distributed and used under the terms of the GNU GPL. */ +#define LOCAL_DEBUG + #include "nest/bird.h" #include "nest/iface.h" #include "nest/protocol.h" #include "nest/route.h" #include "conf/conf.h" +#include "lib/unaligned.h" +#include "lib/socket.h" #include "bgp.h" + +static byte * +bgp_create_notification(struct bgp_conn *conn, byte *buf) +{ + DBG("BGP: Sending notification: code=%d, sub=%d, arg=%d:%d\n", conn->notify_code, conn->notify_subcode, conn->notify_arg, conn->notify_arg_size); + buf[0] = conn->notify_code; + buf[1] = conn->notify_subcode; + switch (conn->notify_arg_size) + { + case 1: + buf[2] = conn->notify_arg; return buf+3; + case 2: + put_u16(buf+2, conn->notify_arg); return buf+4; + case 4: + put_u32(buf+2, conn->notify_arg); return buf+6; + default: + bug("bgp_create_notification: unknown error code size"); + } +} + +static byte * +bgp_create_open(struct bgp_conn *conn, byte *buf) +{ + DBG("BGP: Sending open\n"); + buf[0] = BGP_VERSION; + put_u16(buf+1, conn->bgp->local_as); + put_u16(buf+3, conn->bgp->cf->hold_time); + put_u32(buf+5, conn->bgp->local_id); + buf[9] = 0; /* No optional parameters */ + return buf+10; +} + +static byte * +bgp_create_update(struct bgp_conn *conn, byte *buf) +{ + DBG("BGP: Sending update\n"); + bug("Don't know how to create updates"); +} + +static void +bgp_create_header(byte *buf, unsigned int len, unsigned int type) +{ + memset(buf, 0xff, 16); /* Marker */ + put_u16(buf+16, len); + buf[18] = type; +} + +static void +bgp_fire_tx(struct bgp_conn *conn) +{ + unsigned int s = conn->packets_to_send; + sock *sk = conn->sk; + byte *buf = sk->tbuf; + byte *pkt = buf + BGP_HEADER_LENGTH; + byte *end; + int type; + + if (s & (1 << PKT_SCHEDULE_CLOSE)) + { + conn->packets_to_send = 0; + bug("Scheduled close"); /* FIXME */ + } + if (s & (1 << PKT_NOTIFICATION)) + { + s = 1 << PKT_SCHEDULE_CLOSE; + type = PKT_NOTIFICATION; + end = bgp_create_notification(conn, pkt); + } + else if (s & (1 << PKT_KEEPALIVE)) + { + s &= ~(1 << PKT_KEEPALIVE); + type = PKT_KEEPALIVE; + end = pkt; /* Keepalives carry no data */ + DBG("BGP: Sending keepalive\n"); + } + else if (s & (1 << PKT_OPEN)) + { + s &= ~(1 << PKT_OPEN); + type = PKT_OPEN; + end = bgp_create_open(conn, pkt); + } + else if (s & (1 << PKT_UPDATE)) + { + end = bgp_create_update(conn, pkt); + type = PKT_UPDATE; + if (!end) + { + conn->packets_to_send = 0; + return; + } + } + else + return; + conn->packets_to_send = s; + bgp_create_header(buf, end - buf, type); + sk_send(sk, end - buf); +} + +void +bgp_schedule_packet(struct bgp_conn *conn, int type) +{ + DBG("BGP: Scheduling packet type %d\n", type); + conn->packets_to_send |= 1 << type; + if (conn->sk->tpos != conn->sk->tbuf) + bgp_fire_tx(conn); +} + +void +bgp_tx(sock *sk) +{ + struct bgp_conn *conn = sk->data; + + DBG("BGP: TX hook\n"); + bgp_fire_tx(conn); +} + +int +bgp_rx(sock *sk, int size) +{ + struct bgp_conn *conn = sk->data; + byte *pkt_start = sk->rbuf; + byte *end = pkt_start + size; + + DBG("BGP: RX hook: Got %d bytes\n", size); + while (end >= pkt_start + BGP_HEADER_LENGTH) + { + if (conn->error_flag) + return 1; + bug("Incoming packets not handled"); /* FIXME */ + } + if (pkt_start != sk->rbuf) + { + memmove(sk->rbuf, pkt_start, end - pkt_start); + sk->rpos = sk->rbuf + (end - pkt_start); + } + return 0; +} -- cgit v1.2.3