Exemplo n.º 1
0
void
process_incoming_tun (struct context *c)
{
  struct gc_arena gc = gc_new ();

  perf_push (PERF_PROC_IN_TUN);

  if (c->c2.buf.len > 0)
    c->c2.tun_read_bytes += c->c2.buf.len;

#ifdef LOG_RW
  if (c->c2.log_rw && c->c2.buf.len > 0)
    fprintf (stderr, "r");
#endif

  /* Show packet content */
  dmsg (D_TUN_RW, "TUN READ [%d]", BLEN (&c->c2.buf));

  if (c->c2.buf.len > 0)
    {
      if ((c->options.mode == MODE_POINT_TO_POINT) && (!c->options.allow_recursive_routing))
	drop_if_recursive_routing (c, &c->c2.buf);
      /*
       * The --passtos and --mssfix options require
       * us to examine the IP header (IPv4 or IPv6).
       */
      process_ip_header (c, PIPV4_PASSTOS|PIP_MSSFIX|PIPV4_CLIENT_NAT, &c->c2.buf);

#ifdef PACKET_TRUNCATION_CHECK
      /* if (c->c2.buf.len > 1) --c->c2.buf.len; */
      ipv4_packet_size_verify (BPTR (&c->c2.buf),
			       BLEN (&c->c2.buf),
			       TUNNEL_TYPE (c->c1.tuntap),
			       "PRE_ENCRYPT",
			       &c->c2.n_trunc_pre_encrypt);
#endif

      encrypt_sign (c, true);
    }
  else
    {
      buf_reset (&c->c2.to_link);
    }
  perf_pop ();
  gc_free (&gc);
}
Exemplo n.º 2
0
void
process_outgoing_tun (struct context *c)
{
  struct gc_arena gc = gc_new ();

  /*
   * Set up for write() call to TUN/TAP
   * device.
   */
  if (c->c2.to_tun.len <= 0)
    return;

  perf_push (PERF_PROC_OUT_TUN);

  /*
   * The --mssfix option requires
   * us to examine the IP header (IPv4 or IPv6).
   */
  process_ip_header (c, PIP_MSSFIX|PIPV4_EXTRACT_DHCP_ROUTER|PIPV4_CLIENT_NAT|PIPV4_OUTGOING, &c->c2.to_tun);

  if (c->c2.to_tun.len <= MAX_RW_SIZE_TUN (&c->c2.frame))
    {
      /*
       * Write to TUN/TAP device.
       */
      int size;

#ifdef LOG_RW
      if (c->c2.log_rw)
	fprintf (stderr, "w");
#endif
      dmsg (D_TUN_RW, "TUN WRITE [%d]", BLEN (&c->c2.to_tun));

#ifdef PACKET_TRUNCATION_CHECK
      ipv4_packet_size_verify (BPTR (&c->c2.to_tun),
			       BLEN (&c->c2.to_tun),
			       TUNNEL_TYPE (c->c1.tuntap),
			       "WRITE_TUN",
			       &c->c2.n_trunc_tun_write);
#endif

#ifdef TUN_PASS_BUFFER
      size = write_tun_buffered (c->c1.tuntap, &c->c2.to_tun);
#else
      size = write_tun (c->c1.tuntap, BPTR (&c->c2.to_tun), BLEN (&c->c2.to_tun));
#endif

      if (size > 0)
	c->c2.tun_write_bytes += size;
      check_status (size, "write to TUN/TAP", NULL, c->c1.tuntap);

      /* check written packet size */
      if (size > 0)
	{
	  /* Did we write a different size packet than we intended? */
	  if (size != BLEN (&c->c2.to_tun))
	    msg (D_LINK_ERRORS,
		 "TUN/TAP packet was destructively fragmented on write to %s (tried=%d,actual=%d)",
		 c->c1.tuntap->actual_name,
		 BLEN (&c->c2.to_tun),
		 size);

	  /* indicate activity regarding --inactive parameter */
	  register_activity (c, size);
	}
    }
  else
    {
      /*
       * This should never happen, probably indicates some kind
       * of MTU mismatch.
       */
      msg (D_LINK_ERRORS, "tun packet too large on write (tried=%d,max=%d)",
	   c->c2.to_tun.len,
	   MAX_RW_SIZE_TUN (&c->c2.frame));
    }

  buf_reset (&c->c2.to_tun);

  perf_pop ();
  gc_free (&gc);
}