wireshark/packet-udp.c

/* packet-udp.c
 * Routines for UDP packet disassembly
 *
 * $Id: packet-udp.c,v 1.58 2000/04/04 22:26:36 oabad Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@zing.org>
 * Copyright 1998 Gerald Combs
 *
 * Richard Sharpe, 13-Feb-1999, added dispatch table support and 
 *                              support for tftp.
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
 
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif

#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif

#include <stdio.h>
#include <stdlib.h>

#include <glib.h>
#include "globals.h"
#include "resolv.h"

#include "plugins.h"

#include "packet-auto_rp.h"
#include "packet-bootp.h"
#include "packet-dhis.h"
#include "packet-hsrp.h"
#include "packet-icp.h"
#include "packet-icq.h"
#include "packet-ipx.h"
#include "packet-isakmp.h"
#include "packet-l2tp.h"
#include "packet-nbns.h"
#include "packet-ncp.h"
#include "packet-ntp.h"
#include "packet-radius.h"
#include "packet-rip.h"
#include "packet-ripng.h"
#include "packet-rpc.h"
#include "packet-rx.h"
#include "packet-sap.h"
#include "packet-snmp.h"
#include "packet-srvloc.h"
#include "packet-tacacs.h"
#include "packet-tftp.h"
#include "packet-time.h"
#include "packet-vines.h"
#include "packet-wccp.h"
#include "packet-who.h"

static int proto_udp = -1;		
static int hf_udp_srcport = -1;
static int hf_udp_dstport = -1;
static int hf_udp_port = -1;
static int hf_udp_length = -1;
static int hf_udp_checksum = -1;

static gint ett_udp = -1;

/* UDP structs and definitions */

typedef struct _e_udphdr {
  guint16 uh_sport;
  guint16 uh_dport;
  guint16 uh_ulen;
  guint16 uh_sum;
} e_udphdr;

/* UDP Ports -> should go in packet-udp.h */

#define UDP_PORT_TIME    37
#define UDP_PORT_TACACS  49
#define UDP_PORT_BOOTPS  67
#define UDP_PORT_TFTP    69
#define UDP_PORT_NTP	123
#define UDP_PORT_NBNS	137
#define UDP_PORT_NBDGM	138
#define UDP_PORT_SNMP   161
#define UDP_PORT_SNMP_TRAP 162
#define UDP_PORT_IPX    213		/* RFC 1234 */
#define UDP_PORT_SRVLOC 427
#define UDP_PORT_PIM_RP_DISC 496
#define UDP_PORT_ISAKMP	500
#define UDP_PORT_WHO    513
#define UDP_PORT_RIP    520
#define UDP_PORT_RIPNG  521
#define UDP_PORT_NCP    524
#define UDP_PORT_VINES	573
#define UDP_PORT_RADIUS 1645
#define UDP_PORT_L2TP   1701
#define UDP_PORT_RADIUS_NEW 1812
#define UDP_PORT_RADACCT 1646
#define UDP_PORT_RADACCT_NEW 1813
#define UDP_PORT_HSRP   1985
#define UDP_PORT_ICP    3130
#define UDP_PORT_ICQ	4000
#define UDP_PORT_SAP	9875
#define UDP_PORT_RX_LOW 7000
#define UDP_PORT_RX_HIGH 7009
#define UDP_PORT_RX_AFS_BACKUPS 7021
#define UDP_PORT_WCCP	2048
#define UDP_PORT_DHIS1	58800
#define UDP_PORT_DHIS2	58801

static dissector_table_t udp_dissector_table;

void
dissect_udp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
  e_udphdr  uh;
  guint16    uh_sport, uh_dport, uh_ulen, uh_sum;
  proto_tree *udp_tree;
  proto_item *ti;

  if (!BYTES_ARE_IN_FRAME(offset, sizeof(e_udphdr))) {
    dissect_data(pd, offset, fd, tree);
    return;
  }

  /* Avoids alignment problems on many architectures. */
  memcpy(&uh, &pd[offset], sizeof(e_udphdr));
  uh_sport = ntohs(uh.uh_sport);
  uh_dport = ntohs(uh.uh_dport);
  uh_ulen  = ntohs(uh.uh_ulen);
  uh_sum   = ntohs(uh.uh_sum);
  
  if (check_col(fd, COL_PROTOCOL))
    col_add_str(fd, COL_PROTOCOL, "UDP");
  if (check_col(fd, COL_INFO))
    col_add_fstr(fd, COL_INFO, "Source port: %s  Destination port: %s",
	    get_udp_port(uh_sport), get_udp_port(uh_dport));
    
  if (tree) {
    ti = proto_tree_add_item(tree, proto_udp, offset, 8);
    udp_tree = proto_item_add_subtree(ti, ett_udp);

    proto_tree_add_uint_format(udp_tree, hf_udp_srcport, offset, 2, uh_sport,
	"Source port: %s (%u)", get_udp_port(uh_sport), uh_sport);
    proto_tree_add_uint_format(udp_tree, hf_udp_dstport, offset + 2, 2, uh_dport,
	"Destination port: %s (%u)", get_udp_port(uh_dport), uh_dport);

    proto_tree_add_item_hidden(udp_tree, hf_udp_port, offset, 2, uh_sport);
    proto_tree_add_item_hidden(udp_tree, hf_udp_port, offset+2, 2, uh_dport);

    proto_tree_add_item(udp_tree, hf_udp_length, offset + 4, 2,  uh_ulen);
    proto_tree_add_uint_format(udp_tree, hf_udp_checksum, offset + 6, 2, uh_sum,
	"Checksum: 0x%04x", uh_sum);
  }

  /* Skip over header */
  offset += 8;

  pi.ptype = PT_UDP;
  pi.srcport = uh_sport;
  pi.destport = uh_dport;

  /* ONC RPC.  We can't base this on anything in the UDP header; we have
     to look at the payload.  If "dissect_rpc()" returns TRUE, it was
     an RPC packet, otherwise it's some other type of packet. */
  if (dissect_rpc(pd, offset, fd, tree))
    return;

  /* try to apply the plugins */
#ifdef HAVE_PLUGINS
  {
      plugin *pt_plug = plugin_list;

      if (enabled_plugins_number > 0) {
	  while (pt_plug) {
	      if (pt_plug->enabled && !strcmp(pt_plug->protocol, "udp") &&
		  tree && dfilter_apply(pt_plug->filter, tree, pd)) {
		  pt_plug->dissector(pd, offset, fd, tree);
		  return;
	      }
	      pt_plug = pt_plug->next;
	  }
      }
  }
#endif

  /* XXX - we should do all of this through the table of ports. */
#define PORT_IS(port)	(uh_sport == port || uh_dport == port)
  if (PORT_IS(UDP_PORT_RIP)) {
      /* we should check the source port too (RIP: UDP src and dst port 520) */
      dissect_rip(pd, offset, fd, tree);
  } else if (PORT_IS(UDP_PORT_NCP))
      dissect_ncp(pd, offset, fd, tree); /* XXX -- need to handle nw_server_address */
  else if ((uh_sport >= UDP_PORT_RX_LOW && uh_sport <= UDP_PORT_RX_HIGH) ||
	(uh_dport >= UDP_PORT_RX_LOW && uh_dport <= UDP_PORT_RX_HIGH) ||
	PORT_IS(UDP_PORT_RX_AFS_BACKUPS)) 
      dissect_rx(pd, offset, fd, tree); /* transarc AFS's RX protocol */
  else if (PORT_IS(UDP_PORT_VINES)) {
      /* FIXME: AFAIK, src and dst port must be the same */
      dissect_vines_frp(pd, offset, fd, tree);
  } else if (PORT_IS(UDP_PORT_TFTP)) {
      /* This is the first point of call, but it adds a dynamic call */
      dissector_add("udp.port", MAX(uh_sport, uh_dport), dissect_tftp);  /* Add to table */
      dissect_tftp(pd, offset, fd, tree);
 } else {
      /* OK, find a routine in the table, else use the default */

      if (!dissector_try_port(udp_dissector_table, uh_sport, pd, offset,
				fd, tree) &&
	  !dissector_try_port(udp_dissector_table, uh_dport, pd, offset,
				fd, tree))
	dissect_data(pd, offset, fd, tree);
  }
}

void
proto_register_udp(void)
{
	static hf_register_info hf[] = {
		{ &hf_udp_srcport,
		{ "Source Port",	"udp.srcport", FT_UINT16, BASE_DEC, NULL, 0x0,
			"" }},

		{ &hf_udp_dstport,
		{ "Destination Port",	"udp.dstport", FT_UINT16, BASE_DEC, NULL, 0x0,
			"" }},

		{ &hf_udp_port,
		{ "Source or Destination Port",	"udp.port", FT_UINT16, BASE_DEC,  NULL, 0x0,
			"" }},

		{ &hf_udp_length,
		{ "Length",		"udp.length", FT_UINT16, BASE_DEC, NULL, 0x0,
			"" }},

		{ &hf_udp_checksum,
		{ "Checksum",		"udp.checksum", FT_UINT16, BASE_HEX, NULL, 0x0,
			"" }},
	};
	static gint *ett[] = {
		&ett_udp,
	};

	proto_udp = proto_register_protocol("User Datagram Protocol", "udp");
	proto_register_field_array(proto_udp, hf, array_length(hf));
	proto_register_subtree_array(ett, array_length(ett));

/* subdissector code */
	udp_dissector_table = register_dissector_table(hf_udp_port);

	/* Now add the protocols we know about.
	   XXX - we should add all the UDP ports this way, rather
	   than having the giant "if", just as is now done in
	   "packet-tcp.c". */

	dissector_add("udp.port", UDP_PORT_TIME, dissect_time);
	dissector_add("udp.port", UDP_PORT_TACACS, dissect_tacacs);
	dissector_add("udp.port", UDP_PORT_BOOTPS, dissect_bootp);
	dissector_add("udp.port", UDP_PORT_NTP, dissect_ntp);
	dissector_add("udp.port", UDP_PORT_NBNS, dissect_nbns);
	dissector_add("udp.port", UDP_PORT_NBDGM, dissect_nbdgm);
	dissector_add("udp.port", UDP_PORT_SNMP, dissect_snmp);
	dissector_add("udp.port", UDP_PORT_SNMP_TRAP, dissect_snmp);
	dissector_add("udp.port", UDP_PORT_IPX, dissect_ipx);
	dissector_add("udp.port", UDP_PORT_SRVLOC, dissect_srvloc);
	dissector_add("udp.port", UDP_PORT_PIM_RP_DISC, dissect_auto_rp);
	dissector_add("udp.port", UDP_PORT_ISAKMP, dissect_isakmp);
	dissector_add("udp.port", UDP_PORT_WHO, dissect_who);
	dissector_add("udp.port", UDP_PORT_RIPNG, dissect_ripng);
	dissector_add("udp.port", UDP_PORT_RADIUS, dissect_radius);
	dissector_add("udp.port", UDP_PORT_L2TP, dissect_l2tp);
	dissector_add("udp.port", UDP_PORT_RADIUS_NEW, dissect_radius);
	dissector_add("udp.port", UDP_PORT_RADACCT, dissect_radius);
	dissector_add("udp.port", UDP_PORT_RADACCT_NEW, dissect_radius);
	dissector_add("udp.port", UDP_PORT_HSRP, dissect_hsrp);
	dissector_add("udp.port", UDP_PORT_ICP, dissect_icp);
	dissector_add("udp.port", UDP_PORT_ICQ, dissect_icq);
	dissector_add("udp.port", UDP_PORT_SAP, dissect_sap);
	dissector_add("udp.port", UDP_PORT_WCCP, dissect_wccp);
	dissector_add("udp.port", UDP_PORT_DHIS1, dissect_dhis);
	dissector_add("udp.port", UDP_PORT_DHIS2, dissect_dhis);
}