mirror of
				https://gitlab.labs.nic.cz/labs/bird.git
				synced 2024-05-11 16:54:54 +00:00 
			
		
		
		
	
		
			
				
	
	
		
			829 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			829 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
 | 
						|
 *	BIRD -- BGP Packet Processing
 | 
						|
 *
 | 
						|
 *	(c) 2000 Martin Mares <mj@ucw.cz>
 | 
						|
 *
 | 
						|
 *	Can be freely distributed and used under the terms of the GNU GPL.
 | 
						|
 */
 | 
						|
 | 
						|
#undef 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)
 | 
						|
{
 | 
						|
  struct bgp_proto *p = conn->bgp;
 | 
						|
 | 
						|
  BGP_TRACE(D_PACKETS, "Sending NOTIFICATION(code=%d.%d)", conn->notify_code, conn->notify_subcode);
 | 
						|
  buf[0] = conn->notify_code;
 | 
						|
  buf[1] = conn->notify_subcode;
 | 
						|
  memcpy(buf+2, conn->notify_data, conn->notify_size);
 | 
						|
  return buf + 2 + conn->notify_size;
 | 
						|
}
 | 
						|
 | 
						|
static byte *
 | 
						|
bgp_create_open(struct bgp_conn *conn, byte *buf)
 | 
						|
{
 | 
						|
  struct bgp_proto *p = conn->bgp;
 | 
						|
 | 
						|
  BGP_TRACE(D_PACKETS, "Sending OPEN(ver=%d,as=%d,hold=%d,id=%08x)",
 | 
						|
	    BGP_VERSION, p->local_as, p->cf->hold_time, p->local_id);
 | 
						|
  buf[0] = BGP_VERSION;
 | 
						|
  put_u16(buf+1, p->local_as);
 | 
						|
  put_u16(buf+3, p->cf->hold_time);
 | 
						|
  put_u32(buf+5, p->local_id);
 | 
						|
  buf[9] = 0;				/* No optional parameters */
 | 
						|
  return buf+10;
 | 
						|
}
 | 
						|
 | 
						|
static unsigned int
 | 
						|
bgp_encode_prefixes(struct bgp_proto *p, byte *w, struct bgp_bucket *buck, unsigned int remains)
 | 
						|
{
 | 
						|
  byte *start = w;
 | 
						|
  ip_addr a;
 | 
						|
  int bytes;
 | 
						|
 | 
						|
  while (!EMPTY_LIST(buck->prefixes) && remains >= 5)
 | 
						|
    {
 | 
						|
      struct bgp_prefix *px = SKIP_BACK(struct bgp_prefix, bucket_node, HEAD(buck->prefixes));
 | 
						|
      DBG("\tDequeued route %I/%d\n", px->n.prefix, px->n.pxlen);
 | 
						|
      *w++ = px->n.pxlen;
 | 
						|
      bytes = (px->n.pxlen + 7) / 8;
 | 
						|
      a = px->n.prefix;
 | 
						|
      ipa_hton(a);
 | 
						|
      memcpy(w, &a, bytes);
 | 
						|
      w += bytes;
 | 
						|
      remains -= bytes + 1;
 | 
						|
      rem_node(&px->bucket_node);
 | 
						|
      fib_delete(&p->prefix_fib, px);
 | 
						|
    }
 | 
						|
  return w - start;
 | 
						|
}
 | 
						|
 | 
						|
#ifndef IPV6		/* IPv4 version */
 | 
						|
 | 
						|
static byte *
 | 
						|
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;
 | 
						|
  byte *w;
 | 
						|
  int wd_size = 0;
 | 
						|
  int r_size = 0;
 | 
						|
  int a_size = 0;
 | 
						|
 | 
						|
  w = buf+2;
 | 
						|
  if ((buck = p->withdraw_bucket) && !EMPTY_LIST(buck->prefixes))
 | 
						|
    {
 | 
						|
      DBG("Withdrawn routes:\n");
 | 
						|
      wd_size = bgp_encode_prefixes(p, w, buck, remains);
 | 
						|
      w += wd_size;
 | 
						|
      remains -= wd_size;
 | 
						|
    }
 | 
						|
  put_u16(buf, wd_size);
 | 
						|
 | 
						|
  if (remains >= 2048)
 | 
						|
    {
 | 
						|
      while ((buck = (struct bgp_bucket *) HEAD(p->bucket_queue))->send_node.next)
 | 
						|
	{
 | 
						|
	  if (EMPTY_LIST(buck->prefixes))
 | 
						|
	    {
 | 
						|
	      DBG("Deleting empty bucket %p\n", buck);
 | 
						|
	      rem_node(&buck->send_node);
 | 
						|
	      bgp_free_bucket(p, buck);
 | 
						|
	      continue;
 | 
						|
	    }
 | 
						|
	  DBG("Processing bucket %p\n", buck);
 | 
						|
	  a_size = bgp_encode_attrs(w+2, buck->eattrs, 1024);
 | 
						|
	  put_u16(w, a_size);
 | 
						|
	  w += a_size + 2;
 | 
						|
	  r_size = bgp_encode_prefixes(p, w, buck, remains - a_size);
 | 
						|
	  w += r_size;
 | 
						|
	  break;
 | 
						|
	}
 | 
						|
    }
 | 
						|
  if (!a_size)				/* Attributes not already encoded */
 | 
						|
    {
 | 
						|
      put_u16(w, 0);
 | 
						|
      w += 2;
 | 
						|
    }
 | 
						|
  if (wd_size || r_size)
 | 
						|
    {
 | 
						|
      BGP_TRACE(D_PACKETS, "Sending UPDATE");
 | 
						|
      return w;
 | 
						|
    }
 | 
						|
  else
 | 
						|
    return NULL;
 | 
						|
}
 | 
						|
 | 
						|
#else		/* IPv6 version */
 | 
						|
 | 
						|
static byte *
 | 
						|
bgp_create_update(struct bgp_conn *conn, byte *buf)
 | 
						|
{
 | 
						|
  struct bgp_proto *p = conn->bgp;
 | 
						|
  struct bgp_bucket *buck;
 | 
						|
  int size, is_ll;
 | 
						|
  int remains = BGP_MAX_PACKET_LENGTH - BGP_HEADER_LENGTH - 4;
 | 
						|
  byte *w, *tmp, *tstart;
 | 
						|
  ip_addr ip, ip_ll;
 | 
						|
  ea_list *ea;
 | 
						|
  eattr *nh;
 | 
						|
  neighbor *n;
 | 
						|
 | 
						|
  put_u16(buf, 0);
 | 
						|
  w = buf+4;
 | 
						|
 | 
						|
  if ((buck = p->withdraw_bucket) && !EMPTY_LIST(buck->prefixes))
 | 
						|
    {
 | 
						|
      DBG("Withdrawn routes:\n");
 | 
						|
      tmp = bgp_attach_attr(&ea, bgp_linpool, BA_MP_UNREACH_NLRI, remains-8);
 | 
						|
      *tmp++ = 0;
 | 
						|
      *tmp++ = BGP_AF_IPV6;
 | 
						|
      *tmp++ = 1;
 | 
						|
      ea->attrs[0].u.ptr->length = bgp_encode_prefixes(p, tmp, buck, remains-11);
 | 
						|
      size = bgp_encode_attrs(w, ea, remains);
 | 
						|
      w += size;
 | 
						|
      remains -= size;
 | 
						|
    }
 | 
						|
 | 
						|
  if (remains >= 2048)
 | 
						|
    {
 | 
						|
      while ((buck = (struct bgp_bucket *) HEAD(p->bucket_queue))->send_node.next)
 | 
						|
	{
 | 
						|
	  if (EMPTY_LIST(buck->prefixes))
 | 
						|
	    {
 | 
						|
	      DBG("Deleting empty bucket %p\n", buck);
 | 
						|
	      rem_node(&buck->send_node);
 | 
						|
	      bgp_free_bucket(p, buck);
 | 
						|
	      continue;
 | 
						|
	    }
 | 
						|
	  DBG("Processing bucket %p\n", buck);
 | 
						|
	  size = bgp_encode_attrs(w, buck->eattrs, 1024);
 | 
						|
	  w += size;
 | 
						|
	  remains -= size;
 | 
						|
	  tstart = tmp = bgp_attach_attr(&ea, bgp_linpool, BA_MP_REACH_NLRI, remains-8);
 | 
						|
	  *tmp++ = 0;
 | 
						|
	  *tmp++ = BGP_AF_IPV6;
 | 
						|
	  *tmp++ = 1;
 | 
						|
	  nh = ea_find(buck->eattrs, EA_CODE(EAP_BGP, BA_NEXT_HOP));
 | 
						|
	  ASSERT(nh);
 | 
						|
	  ip = *(ip_addr *) nh->u.ptr->data;
 | 
						|
	  if (ipa_equal(ip, p->local_addr))
 | 
						|
	    is_ll = 1;
 | 
						|
	  else
 | 
						|
	    {
 | 
						|
	      n = neigh_find(&p->p, &ip, 0);
 | 
						|
	      if (n && n->iface == p->neigh->iface)
 | 
						|
		is_ll = 1;
 | 
						|
	      else
 | 
						|
		is_ll = 0;
 | 
						|
	    }
 | 
						|
	  if (is_ll)
 | 
						|
	    {
 | 
						|
	      *tmp++ = 32;
 | 
						|
	      ip_ll = ipa_or(ipa_build(0xfe80,0,0,0), ipa_and(ip, ipa_build(0,0,~0,~0)));
 | 
						|
	      ipa_hton(ip);
 | 
						|
	      memcpy(tmp, &ip, 16);
 | 
						|
	      ipa_hton(ip_ll);
 | 
						|
	      memcpy(tmp+16, &ip_ll, 16);
 | 
						|
	      tmp += 32;
 | 
						|
	    }
 | 
						|
	  else
 | 
						|
	    {
 | 
						|
	      *tmp++ = 16;
 | 
						|
	      ipa_hton(ip);
 | 
						|
	      memcpy(tmp, &ip, 16);
 | 
						|
	      tmp += 16;
 | 
						|
	    }
 | 
						|
	  *tmp++ = 0;			/* No SNPA information */
 | 
						|
	  tmp += bgp_encode_prefixes(p, tmp, buck, remains - (8+3+32+1));
 | 
						|
	  ea->attrs[0].u.ptr->length = tmp - tstart;
 | 
						|
	  w += bgp_encode_attrs(w, ea, remains);
 | 
						|
	  break;
 | 
						|
	}
 | 
						|
    }
 | 
						|
 | 
						|
  size = w - (buf+4);
 | 
						|
  put_u16(buf+2, size);
 | 
						|
  lp_flush(bgp_linpool);
 | 
						|
  if (size)
 | 
						|
    {
 | 
						|
      BGP_TRACE(D_PACKETS, "Sending UPDATE");
 | 
						|
      return w;
 | 
						|
    }
 | 
						|
  else
 | 
						|
    return NULL;
 | 
						|
}
 | 
						|
 | 
						|
#endif
 | 
						|
 | 
						|
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 int
 | 
						|
bgp_fire_tx(struct bgp_conn *conn)
 | 
						|
{
 | 
						|
  struct bgp_proto *p = conn->bgp;
 | 
						|
  unsigned int s = conn->packets_to_send;
 | 
						|
  sock *sk = conn->sk;
 | 
						|
  byte *buf, *pkt, *end;
 | 
						|
  int type;
 | 
						|
 | 
						|
  if (!sk)
 | 
						|
    {
 | 
						|
      conn->packets_to_send = 0;
 | 
						|
      return 0;
 | 
						|
    }
 | 
						|
  buf = sk->tbuf;
 | 
						|
  pkt = buf + BGP_HEADER_LENGTH;
 | 
						|
 | 
						|
  if (s & (1 << PKT_SCHEDULE_CLOSE))
 | 
						|
    {
 | 
						|
      bgp_close_conn(conn);
 | 
						|
      return 0;
 | 
						|
    }
 | 
						|
  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 */
 | 
						|
      BGP_TRACE(D_PACKETS, "Sending KEEPALIVE");
 | 
						|
      bgp_start_timer(conn->keepalive_timer, conn->keepalive_time);
 | 
						|
    }
 | 
						|
  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 0;
 | 
						|
	}
 | 
						|
    }
 | 
						|
  else
 | 
						|
    return 0;
 | 
						|
  conn->packets_to_send = s;
 | 
						|
  bgp_create_header(buf, end - buf, type);
 | 
						|
  return 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 && conn->sk->tpos == conn->sk->tbuf)
 | 
						|
    while (bgp_fire_tx(conn))
 | 
						|
      ;
 | 
						|
}
 | 
						|
 | 
						|
void
 | 
						|
bgp_tx(sock *sk)
 | 
						|
{
 | 
						|
  struct bgp_conn *conn = sk->data;
 | 
						|
 | 
						|
  DBG("BGP: TX hook\n");
 | 
						|
  while (bgp_fire_tx(conn))
 | 
						|
    ;
 | 
						|
}
 | 
						|
 | 
						|
static int
 | 
						|
bgp_parse_options(struct bgp_conn *conn, byte *opt, int len)
 | 
						|
{
 | 
						|
  while (len > 0)
 | 
						|
    {
 | 
						|
      if (len < 2 || len < 2 + opt[1])
 | 
						|
	{ bgp_error(conn, 2, 0, NULL, 0); return 0; }
 | 
						|
#ifdef LOCAL_DEBUG
 | 
						|
      {
 | 
						|
	int i;
 | 
						|
	DBG("\tOption %02x:", opt[0]);
 | 
						|
	for(i=0; i<opt[1]; i++)
 | 
						|
	  DBG(" %02x", opt[2+i]);
 | 
						|
	DBG("\n");
 | 
						|
      }
 | 
						|
#endif
 | 
						|
      switch (opt[0])
 | 
						|
	{
 | 
						|
	case 2:
 | 
						|
	  /* Defined in draft-ietf-idr-bgp4-cap-neg-06 */
 | 
						|
	  /* We can safely ignore all capabilities */
 | 
						|
	  break;
 | 
						|
	default:
 | 
						|
	  /*
 | 
						|
	   *  BGP specs don't tell us to send which option
 | 
						|
	   *  we didn't recognize, but it's common practice
 | 
						|
	   *  to do so. Also, capability negotiation with
 | 
						|
	   *  Cisco routers doesn't work without that.
 | 
						|
	   */
 | 
						|
	  bgp_error(conn, 2, 4, opt, opt[1]);
 | 
						|
	  return 0;
 | 
						|
	}
 | 
						|
      len -= 2 + opt[1];
 | 
						|
      opt += 2 + opt[1];
 | 
						|
    }
 | 
						|
  return 0;
 | 
						|
}
 | 
						|
 | 
						|
static void
 | 
						|
bgp_rx_open(struct bgp_conn *conn, byte *pkt, int len)
 | 
						|
{
 | 
						|
  struct bgp_conn *other;
 | 
						|
  struct bgp_proto *p = conn->bgp;
 | 
						|
  struct bgp_config *cf = p->cf;
 | 
						|
  unsigned as, hold;
 | 
						|
  u32 id;
 | 
						|
 | 
						|
  /* Check state */
 | 
						|
  if (conn->state != BS_OPENSENT)
 | 
						|
    { bgp_error(conn, 5, 0, NULL, 0); }
 | 
						|
 | 
						|
  /* Check message contents */
 | 
						|
  if (len < 29 || len != 29 + pkt[28])
 | 
						|
    { bgp_error(conn, 1, 2, pkt+16, 2); return; }
 | 
						|
  if (pkt[19] != BGP_VERSION)
 | 
						|
    { bgp_error(conn, 2, 1, pkt+19, 1); return; } /* RFC 1771 says 16 bits, draft-09 tells to use 8 */
 | 
						|
  as = get_u16(pkt+20);
 | 
						|
  hold = get_u16(pkt+22);
 | 
						|
  id = get_u32(pkt+24);
 | 
						|
  BGP_TRACE(D_PACKETS, "Got OPEN(as=%d,hold=%d,id=%08x)", as, hold, id);
 | 
						|
  if (cf->remote_as && as != p->remote_as)
 | 
						|
    { bgp_error(conn, 2, 2, pkt+20, -2); return; }
 | 
						|
  if (hold > 0 && hold < 3)
 | 
						|
    { bgp_error(conn, 2, 6, pkt+22, 2); return; }
 | 
						|
  p->remote_id = id;
 | 
						|
  if (bgp_parse_options(conn, pkt+29, pkt[28]))
 | 
						|
    return;
 | 
						|
  if (!id || id == 0xffffffff || id == p->local_id)
 | 
						|
    { bgp_error(conn, 2, 3, pkt+24, -4); return; }
 | 
						|
 | 
						|
  /* Check the other connection */
 | 
						|
  other = (conn == &p->outgoing_conn) ? &p->incoming_conn : &p->outgoing_conn;
 | 
						|
  switch (other->state)
 | 
						|
    {
 | 
						|
    case BS_IDLE:
 | 
						|
      break;
 | 
						|
    case BS_CONNECT:
 | 
						|
    case BS_ACTIVE:
 | 
						|
    case BS_OPENSENT:
 | 
						|
      BGP_TRACE(D_EVENTS, "Connection collision, giving up the other connection");
 | 
						|
      bgp_close_conn(other);
 | 
						|
      break;
 | 
						|
    case BS_OPENCONFIRM:
 | 
						|
      if ((p->local_id < id) == (conn == &p->incoming_conn))
 | 
						|
	{
 | 
						|
	  /* Should close the other connection */
 | 
						|
	  BGP_TRACE(D_EVENTS, "Connection collision, giving up the other connection");
 | 
						|
	  bgp_error(other, 6, 0, NULL, 0);
 | 
						|
	  break;
 | 
						|
	}
 | 
						|
      /* Fall thru */
 | 
						|
    case BS_ESTABLISHED:
 | 
						|
      /* Should close this connection */
 | 
						|
      BGP_TRACE(D_EVENTS, "Connection collision, giving up this connection");
 | 
						|
      bgp_error(conn, 6, 0, NULL, 0);
 | 
						|
      return;
 | 
						|
    default:
 | 
						|
      bug("bgp_rx_open: Unknown state");
 | 
						|
    }
 | 
						|
 | 
						|
  /* Make this connection primary */
 | 
						|
  conn->primary = 1;
 | 
						|
  p->conn = conn;
 | 
						|
 | 
						|
  /* Update our local variables */
 | 
						|
  if (hold < p->cf->hold_time)
 | 
						|
    conn->hold_time = hold;
 | 
						|
  else
 | 
						|
    conn->hold_time = p->cf->hold_time;
 | 
						|
  conn->keepalive_time = p->cf->keepalive_time ? : conn->hold_time / 3;
 | 
						|
  p->remote_as = as;
 | 
						|
  p->remote_id = id;
 | 
						|
  DBG("BGP: Hold timer set to %d, keepalive to %d, AS to %d, ID to %x\n", conn->hold_time, conn->keepalive_time, p->remote_as, p->remote_id);
 | 
						|
 | 
						|
  bgp_schedule_packet(conn, PKT_KEEPALIVE);
 | 
						|
  bgp_start_timer(conn->hold_timer, conn->hold_time);
 | 
						|
  conn->state = BS_OPENCONFIRM;
 | 
						|
}
 | 
						|
 | 
						|
#define DECODE_PREFIX(pp, ll) do {		\
 | 
						|
  int b = *pp++;				\
 | 
						|
  int q;					\
 | 
						|
  ll--;						\
 | 
						|
  if (b > BITS_PER_IP_ADDRESS) { err=10; goto bad; } \
 | 
						|
  q = (b+7) / 8;				\
 | 
						|
  if (ll < q) { err=1; goto bad; }		\
 | 
						|
  memcpy(&prefix, pp, q);			\
 | 
						|
  pp += q;					\
 | 
						|
  ll -= q;					\
 | 
						|
  ipa_ntoh(prefix);				\
 | 
						|
  prefix = ipa_and(prefix, ipa_mkmask(b));	\
 | 
						|
  pxlen = b;					\
 | 
						|
} while (0)
 | 
						|
 | 
						|
static inline int
 | 
						|
bgp_get_nexthop(struct bgp_proto *bgp, rta *a)
 | 
						|
{
 | 
						|
  neighbor *neigh;
 | 
						|
  ip_addr nexthop;
 | 
						|
  struct eattr *nh = ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_NEXT_HOP));
 | 
						|
  ASSERT(nh);
 | 
						|
  nexthop = *(ip_addr *) nh->u.ptr->data;
 | 
						|
  if (ipa_equal(nexthop, bgp->local_addr))
 | 
						|
    {
 | 
						|
      DBG("BGP: Loop!\n");
 | 
						|
      return 0;
 | 
						|
    }
 | 
						|
  neigh = neigh_find(&bgp->p, &nexthop, 0) ? : bgp->neigh;
 | 
						|
  a->gw = neigh->addr;
 | 
						|
  a->iface = neigh->iface;
 | 
						|
  return 1;
 | 
						|
}
 | 
						|
 | 
						|
#ifndef IPV6		/* IPv4 version */
 | 
						|
 | 
						|
static void
 | 
						|
bgp_do_rx_update(struct bgp_conn *conn,
 | 
						|
		 byte *withdrawn, int withdrawn_len,
 | 
						|
		 byte *nlri, int nlri_len,
 | 
						|
		 byte *attrs, int attr_len)
 | 
						|
{
 | 
						|
  struct bgp_proto *p = conn->bgp;
 | 
						|
  rta *a0;
 | 
						|
  rta *a = NULL;
 | 
						|
  ip_addr prefix;
 | 
						|
  net *n;
 | 
						|
  rte e;
 | 
						|
  int err = 0, pxlen;
 | 
						|
 | 
						|
  /* Withdraw routes */
 | 
						|
  while (withdrawn_len)
 | 
						|
    {
 | 
						|
      DECODE_PREFIX(withdrawn, withdrawn_len);
 | 
						|
      DBG("Withdraw %I/%d\n", prefix, pxlen);
 | 
						|
      if (n = net_find(p->p.table, prefix, pxlen))
 | 
						|
	rte_update(p->p.table, n, &p->p, NULL);
 | 
						|
    }
 | 
						|
 | 
						|
  if (!attr_len && !nlri_len)		/* shortcut */
 | 
						|
    return;
 | 
						|
 | 
						|
  a0 = bgp_decode_attrs(conn, attrs, attr_len, bgp_linpool, nlri_len);
 | 
						|
  if (a0 && nlri_len && bgp_get_nexthop(p, a0))
 | 
						|
    {
 | 
						|
      a = rta_lookup(a0);
 | 
						|
      while (nlri_len)
 | 
						|
	{
 | 
						|
	  rte *e;
 | 
						|
	  DECODE_PREFIX(nlri, nlri_len);
 | 
						|
	  DBG("Add %I/%d\n", prefix, pxlen);
 | 
						|
	  e = rte_get_temp(rta_clone(a));
 | 
						|
	  n = net_get(p->p.table, prefix, pxlen);
 | 
						|
	  e->net = n;
 | 
						|
	  e->pflags = 0;
 | 
						|
	  rte_update(p->p.table, n, &p->p, e);
 | 
						|
	}
 | 
						|
    }
 | 
						|
bad:
 | 
						|
  if (a)
 | 
						|
    rta_free(a);
 | 
						|
  if (err)
 | 
						|
    bgp_error(conn, 3, err, NULL, 0);
 | 
						|
  return;
 | 
						|
}
 | 
						|
 | 
						|
#else			/* IPv6 version */
 | 
						|
 | 
						|
#define DO_NLRI(name)					\
 | 
						|
  start = x = p->name##_start;				\
 | 
						|
  len = len0 = p->name##_len;				\
 | 
						|
  if (len)						\
 | 
						|
    {							\
 | 
						|
      if (len < 3) goto bad;				\
 | 
						|
      af = get_u16(x);					\
 | 
						|
      sub = x[2];					\
 | 
						|
      x += 3;						\
 | 
						|
      len -= 3;						\
 | 
						|
      DBG("\tNLRI AF=%d sub=%d len=%d\n", af, sub, len);\
 | 
						|
    }							\
 | 
						|
  else							\
 | 
						|
    af = 0;						\
 | 
						|
  if (af == BGP_AF_IPV6)
 | 
						|
 | 
						|
static void
 | 
						|
bgp_do_rx_update(struct bgp_conn *conn,
 | 
						|
		 byte *withdrawn, int withdrawn_len,
 | 
						|
		 byte *nlri, int nlri_len,
 | 
						|
		 byte *attrs, int attr_len)
 | 
						|
{
 | 
						|
  struct bgp_proto *p = conn->bgp;
 | 
						|
  byte *start, *x;
 | 
						|
  int len, len0;
 | 
						|
  unsigned af, sub;
 | 
						|
  rta *a0;
 | 
						|
  rta *a = NULL;
 | 
						|
  ip_addr prefix;
 | 
						|
  net *n;
 | 
						|
  rte e;
 | 
						|
  int err = 0, pxlen;
 | 
						|
 | 
						|
  p->mp_reach_len = 0;
 | 
						|
  p->mp_unreach_len = 0;
 | 
						|
  a0 = bgp_decode_attrs(conn, attrs, attr_len, bgp_linpool, 0);
 | 
						|
  if (!a0)
 | 
						|
    return;
 | 
						|
 | 
						|
  DO_NLRI(mp_unreach)
 | 
						|
    {
 | 
						|
      while (len)
 | 
						|
	{
 | 
						|
	  DECODE_PREFIX(x, len);
 | 
						|
	  DBG("Withdraw %I/%d\n", prefix, pxlen);
 | 
						|
	  if (n = net_find(p->p.table, prefix, pxlen))
 | 
						|
	    rte_update(p->p.table, n, &p->p, NULL);
 | 
						|
	}
 | 
						|
    }
 | 
						|
 | 
						|
  DO_NLRI(mp_reach)
 | 
						|
    {
 | 
						|
      int i;
 | 
						|
 | 
						|
      /* Create fake NEXT_HOP attribute */
 | 
						|
      if (len < 1 || (*x != 16 && *x != 32) || len < *x + 2)
 | 
						|
	goto bad;
 | 
						|
      memcpy(bgp_attach_attr(&a0->eattrs, bgp_linpool, BA_NEXT_HOP, 16), x+1, 16);
 | 
						|
      len -= *x + 1;
 | 
						|
      x += *x + 1;
 | 
						|
 | 
						|
      /* Ignore SNPA info */
 | 
						|
      i = *x++;
 | 
						|
      while (i--)
 | 
						|
	{
 | 
						|
	  if (len < 1 || len < 1 + *x)
 | 
						|
	    goto bad;
 | 
						|
	  len -= *x + 1;
 | 
						|
	  x += *x + 1;
 | 
						|
	}
 | 
						|
 | 
						|
      if (bgp_get_nexthop(p, a0))
 | 
						|
	{
 | 
						|
	  a = rta_lookup(a0);
 | 
						|
	  while (len)
 | 
						|
	    {
 | 
						|
	      rte *e;
 | 
						|
	      DECODE_PREFIX(x, len);
 | 
						|
	      DBG("Add %I/%d\n", prefix, pxlen);
 | 
						|
	      e = rte_get_temp(rta_clone(a));
 | 
						|
	      n = net_get(p->p.table, prefix, pxlen);
 | 
						|
	      e->net = n;
 | 
						|
	      e->pflags = 0;
 | 
						|
	      rte_update(p->p.table, n, &p->p, e);
 | 
						|
	    }
 | 
						|
	  rta_free(a);
 | 
						|
	}
 | 
						|
    }
 | 
						|
 | 
						|
  return;
 | 
						|
 | 
						|
bad:
 | 
						|
  bgp_error(conn, 3, 9, start, len0);
 | 
						|
  if (a)
 | 
						|
    rta_free(a);
 | 
						|
  return;
 | 
						|
}
 | 
						|
 | 
						|
#endif
 | 
						|
 | 
						|
static void
 | 
						|
bgp_rx_update(struct bgp_conn *conn, byte *pkt, int len)
 | 
						|
{
 | 
						|
  struct bgp_proto *p = conn->bgp;
 | 
						|
  byte *withdrawn, *attrs, *nlri;
 | 
						|
  int withdrawn_len, attr_len, nlri_len;
 | 
						|
 | 
						|
  BGP_TRACE(D_PACKETS, "Got UPDATE");
 | 
						|
  if (conn->state != BS_ESTABLISHED)
 | 
						|
    { bgp_error(conn, 5, 0, NULL, 0); return; }
 | 
						|
  bgp_start_timer(conn->hold_timer, conn->hold_time);
 | 
						|
 | 
						|
  /* Find parts of the packet and check sizes */
 | 
						|
  if (len < 23)
 | 
						|
    {
 | 
						|
      bgp_error(conn, 1, 2, pkt+16, 2);
 | 
						|
      return;
 | 
						|
    }
 | 
						|
  withdrawn = pkt + 21;
 | 
						|
  withdrawn_len = get_u16(pkt + 19);
 | 
						|
  if (withdrawn_len + 23 > len)
 | 
						|
    goto malformed;
 | 
						|
  attrs = withdrawn + withdrawn_len + 2;
 | 
						|
  attr_len = get_u16(attrs - 2);
 | 
						|
  if (withdrawn_len + attr_len + 23 > len)
 | 
						|
    goto malformed;
 | 
						|
  nlri = attrs + attr_len;
 | 
						|
  nlri_len = len - withdrawn_len - attr_len - 23;
 | 
						|
  if (!attr_len && nlri_len)
 | 
						|
    goto malformed;
 | 
						|
  DBG("Sizes: withdrawn=%d, attrs=%d, NLRI=%d\n", withdrawn_len, attr_len, nlri_len);
 | 
						|
 | 
						|
  lp_flush(bgp_linpool);
 | 
						|
 | 
						|
  bgp_do_rx_update(conn, withdrawn, withdrawn_len, nlri, nlri_len, attrs, attr_len);
 | 
						|
  return;
 | 
						|
 | 
						|
malformed:
 | 
						|
  bgp_error(conn, 3, 1, NULL, 0);
 | 
						|
}
 | 
						|
 | 
						|
static struct {
 | 
						|
  byte major, minor;
 | 
						|
  byte *msg;
 | 
						|
} bgp_msg_table[] = {
 | 
						|
  { 1, 0, "Invalid message header" },
 | 
						|
  { 1, 1, "Connection not synchronized" },
 | 
						|
  { 1, 2, "Bad message length" },
 | 
						|
  { 1, 3, "Bad message type" },
 | 
						|
  { 2, 0, "Invalid OPEN message" },
 | 
						|
  { 2, 1, "Unsupported version number" },
 | 
						|
  { 2, 2, "Bad peer AS" },
 | 
						|
  { 2, 3, "Bad BGP identifier" },
 | 
						|
  { 2, 4, "Unsupported optional parameter" },
 | 
						|
  { 2, 5, "Authentication failure" },
 | 
						|
  { 2, 6, "Unacceptable hold time" },
 | 
						|
  { 2, 7, "Required capability missing" }, /* capability negotiation draft */
 | 
						|
  { 3, 0, "Invalid UPDATE message" },
 | 
						|
  { 3, 1, "Malformed attribute list" },
 | 
						|
  { 3, 2, "Unrecognized well-known attribute" },
 | 
						|
  { 3, 3, "Missing mandatory attribute" },
 | 
						|
  { 3, 4, "Invalid attribute flags" },
 | 
						|
  { 3, 5, "Invalid attribute length" },
 | 
						|
  { 3, 6, "Invalid ORIGIN attribute" },
 | 
						|
  { 3, 7, "AS routing loop" },		/* Deprecated */
 | 
						|
  { 3, 8, "Invalid NEXT_HOP attribute" },
 | 
						|
  { 3, 9, "Optional attribute error" },
 | 
						|
  { 3, 10, "Invalid network field" },
 | 
						|
  { 3, 11, "Malformed AS_PATH" },
 | 
						|
  { 4, 0, "Hold timer expired" },
 | 
						|
  { 5, 0, "Finite state machine error" },
 | 
						|
  { 6, 0, "Cease" }
 | 
						|
};
 | 
						|
 | 
						|
void
 | 
						|
bgp_log_error(struct bgp_proto *p, char *msg, unsigned code, unsigned subcode, byte *data, unsigned len)
 | 
						|
{
 | 
						|
  byte *name, namebuf[16];
 | 
						|
  byte *t, argbuf[36];
 | 
						|
  unsigned i;
 | 
						|
 | 
						|
  if (code == 6 && !subcode)		/* Don't report Cease messages */
 | 
						|
    return;
 | 
						|
 | 
						|
  bsprintf(namebuf, "%d.%d", code, subcode);
 | 
						|
  name = namebuf;
 | 
						|
  for (i=0; i < ARRAY_SIZE(bgp_msg_table); i++)
 | 
						|
    if (bgp_msg_table[i].major == code && bgp_msg_table[i].minor == subcode)
 | 
						|
      {
 | 
						|
	name = bgp_msg_table[i].msg;
 | 
						|
	break;
 | 
						|
      }
 | 
						|
  t = argbuf;
 | 
						|
  if (len)
 | 
						|
    {
 | 
						|
      *t++ = ':';
 | 
						|
      *t++ = ' ';
 | 
						|
      if (len > 16)
 | 
						|
	len = 16;
 | 
						|
      for (i=0; i<len; i++)
 | 
						|
	t += bsprintf(t, "%02x", data[i]);
 | 
						|
    }
 | 
						|
  *t = 0;
 | 
						|
  log(L_REMOTE "%s: %s: %s%s", p->p.name, msg, name, argbuf);
 | 
						|
}
 | 
						|
 | 
						|
static void
 | 
						|
bgp_rx_notification(struct bgp_conn *conn, byte *pkt, int len)
 | 
						|
{
 | 
						|
  if (len < 21)
 | 
						|
    {
 | 
						|
      bgp_error(conn, 1, 2, pkt+16, 2);
 | 
						|
      return;
 | 
						|
    }
 | 
						|
  bgp_log_error(conn->bgp, "Received error notification", pkt[19], pkt[20], pkt+21, len-21);
 | 
						|
  conn->error_flag = 1;
 | 
						|
  if (conn->primary)
 | 
						|
    proto_notify_state(&conn->bgp->p, PS_STOP);
 | 
						|
  bgp_schedule_packet(conn, PKT_SCHEDULE_CLOSE);
 | 
						|
}
 | 
						|
 | 
						|
static void
 | 
						|
bgp_rx_keepalive(struct bgp_conn *conn, byte *pkt, unsigned len)
 | 
						|
{
 | 
						|
  struct bgp_proto *p = conn->bgp;
 | 
						|
 | 
						|
  BGP_TRACE(D_PACKETS, "Got KEEPALIVE");
 | 
						|
  bgp_start_timer(conn->hold_timer, conn->hold_time);
 | 
						|
  switch (conn->state)
 | 
						|
    {
 | 
						|
    case BS_OPENCONFIRM:
 | 
						|
      DBG("BGP: UP!!!\n");
 | 
						|
      conn->state = BS_ESTABLISHED;
 | 
						|
      bgp_attr_init(conn->bgp);
 | 
						|
      proto_notify_state(&conn->bgp->p, PS_UP);
 | 
						|
      break;
 | 
						|
    case BS_ESTABLISHED:
 | 
						|
      break;
 | 
						|
    default:
 | 
						|
      bgp_error(conn, 5, 0, NULL, 0);
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
static void
 | 
						|
bgp_rx_packet(struct bgp_conn *conn, byte *pkt, unsigned len)
 | 
						|
{
 | 
						|
  DBG("BGP: Got packet %02x (%d bytes)\n", pkt[18], len);
 | 
						|
  switch (pkt[18])
 | 
						|
    {
 | 
						|
    case PKT_OPEN:		return bgp_rx_open(conn, pkt, len);
 | 
						|
    case PKT_UPDATE:		return bgp_rx_update(conn, pkt, len);
 | 
						|
    case PKT_NOTIFICATION:      return bgp_rx_notification(conn, pkt, len);
 | 
						|
    case PKT_KEEPALIVE:		return bgp_rx_keepalive(conn, pkt, len);
 | 
						|
    default:			bgp_error(conn, 1, 3, pkt+18, 1);
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
int
 | 
						|
bgp_rx(sock *sk, int size)
 | 
						|
{
 | 
						|
  struct bgp_conn *conn = sk->data;
 | 
						|
  byte *pkt_start = sk->rbuf;
 | 
						|
  byte *end = pkt_start + size;
 | 
						|
  unsigned i, len;
 | 
						|
 | 
						|
  DBG("BGP: RX hook: Got %d bytes\n", size);
 | 
						|
  while (end >= pkt_start + BGP_HEADER_LENGTH)
 | 
						|
    {
 | 
						|
      if (conn->error_flag)
 | 
						|
	{
 | 
						|
	  /*
 | 
						|
	   *  We still need to remember the erroneous packet, so that
 | 
						|
	   *  we can generate error notifications properly.  To avoid
 | 
						|
	   *  subsequent reads rewriting the buffer, we just reset the
 | 
						|
	   *  rx_hook.
 | 
						|
	   */
 | 
						|
	  DBG("BGP: Error, dropping input\n");
 | 
						|
	  sk->rx_hook = NULL;
 | 
						|
	  return 0;
 | 
						|
	}
 | 
						|
      for(i=0; i<16; i++)
 | 
						|
	if (pkt_start[i] != 0xff)
 | 
						|
	  {
 | 
						|
	    bgp_error(conn, 1, 1, NULL, 0);
 | 
						|
	    break;
 | 
						|
	  }
 | 
						|
      len = get_u16(pkt_start+16);
 | 
						|
      if (len < BGP_HEADER_LENGTH || len > BGP_MAX_PACKET_LENGTH)
 | 
						|
	{
 | 
						|
	  bgp_error(conn, 1, 2, pkt_start+16, 2);
 | 
						|
	  break;
 | 
						|
	}
 | 
						|
      if (end < pkt_start + len)
 | 
						|
	break;
 | 
						|
      bgp_rx_packet(conn, pkt_start, len);
 | 
						|
      pkt_start += len;
 | 
						|
    }
 | 
						|
  if (pkt_start != sk->rbuf)
 | 
						|
    {
 | 
						|
      memmove(sk->rbuf, pkt_start, end - pkt_start);
 | 
						|
      sk->rpos = sk->rbuf + (end - pkt_start);
 | 
						|
    }
 | 
						|
  return 0;
 | 
						|
}
 |