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Construction of BGP packets.

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This commit is contained in:
Martin Mares 2000-03-21 15:53:50 +00:00
parent a8f944cb6e
commit 72a6ef11fe
4 changed files with 160 additions and 15 deletions
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2
proto/bgp/Makefile
View file

@ -1,4 +1,4 @@
source=bgp.c attrs.c
source=bgp.c attrs.c packets.c
root-rel=../../
dir-name=proto/bgp

14
proto/bgp/bgp.c
View file

@ -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;

18
proto/bgp/bgp.h
View file

@ -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 */

141
proto/bgp/packets.c
View file

@ -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;
}