wireshark/packet-ipv6.c

/* packet-ipv6.c
 * Routines for IPv6 packet disassembly 
 *
 * $Id: packet-ipv6.c,v 1.55 2001/04/23 03:37:31 guy Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@ethereal.com>
 *
 * Copyright 1998 Gerald Combs
 *
 * MobileIPv6 support added by Tomislav Borosa <tomislav.borosa@siemens.hr>
 *
 * 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_SYS_SOCKET_h
#include <sys/socket.h>
#endif

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

#include <string.h>
#include <stdio.h>
#include <glib.h>
#include "packet.h"
#include "packet-ip.h"
#include "packet-ipsec.h"
#include "packet-ipv6.h"
#include "packet-tcp.h"
#include "packet-udp.h"
#include "resolv.h"
#include "ipproto.h"
#include "etypes.h"
#include "ppptypes.h"
#include "aftypes.h"

/*
 * NOTE: ipv6.nxt is not very useful as we will have chained header.
 * now testing ipv6.final, but it raises SEGV.
#define TEST_FINALHDR
 */

static int proto_ipv6 = -1;
static int hf_ipv6_version = -1;
static int hf_ipv6_class = -1;
static int hf_ipv6_flow = -1;
static int hf_ipv6_plen = -1;
static int hf_ipv6_nxt = -1;
static int hf_ipv6_hlim = -1;
static int hf_ipv6_src = -1;
static int hf_ipv6_dst = -1;
static int hf_ipv6_addr = -1;
#ifdef TEST_FINALHDR
static int hf_ipv6_final = -1;
#endif

/* BT INSERT BEGIN */
static int hf_ipv6_mipv6_type = -1;
static int hf_ipv6_mipv6_length = -1;
static int hf_ipv6_mipv6_a_flag = -1;
static int hf_ipv6_mipv6_h_flag = -1;
static int hf_ipv6_mipv6_r_flag = -1;
static int hf_ipv6_mipv6_d_flag = -1;
static int hf_ipv6_mipv6_m_flag = -1;
static int hf_ipv6_mipv6_b_flag = -1;
static int hf_ipv6_mipv6_prefix_length = -1;
static int hf_ipv6_mipv6_sequence_number = -1;
static int hf_ipv6_mipv6_life_time = -1;
static int hf_ipv6_mipv6_status = -1;
static int hf_ipv6_mipv6_refresh = -1;
static int hf_ipv6_mipv6_home_address = -1;
static int hf_ipv6_mipv6_sub_type = -1;
static int hf_ipv6_mipv6_sub_length = -1;
static int hf_ipv6_mipv6_sub_unique_ID = -1;
static int hf_ipv6_mipv6_sub_alternative_COA = -1;
/* BT INSERT END */

static gint ett_ipv6 = -1;

#ifndef offsetof
#define	offsetof(type, member)	((size_t)(&((type *)0)->member))
#endif

static int
dissect_routing6(tvbuff_t *tvb, int offset, proto_tree *tree) {
    struct ip6_rthdr rt;
    int len;
    proto_tree *rthdr_tree;
	proto_item *ti;
    char buf[sizeof(struct ip6_rthdr0) + sizeof(struct e_in6_addr) * 23];
	
    tvb_memcpy(tvb, (guint8 *)&rt, offset, sizeof(rt));
    len = (rt.ip6r_len + 1) << 3;

    if (tree) {
	/* !!! specify length */
	ti = proto_tree_add_text(tree, tvb, offset, len,
	    "Routing Header, Type %u", rt.ip6r_type);
	rthdr_tree = proto_item_add_subtree(ti, ett_ipv6);

	proto_tree_add_text(rthdr_tree, tvb,
	    offset + offsetof(struct ip6_rthdr, ip6r_nxt), 1,
	    "Next header: %s (0x%02x)", ipprotostr(rt.ip6r_nxt), rt.ip6r_nxt);
	proto_tree_add_text(rthdr_tree, tvb,
	    offset + offsetof(struct ip6_rthdr, ip6r_len), 1,
	    "Length: %u (%d bytes)", rt.ip6r_len, len);
	proto_tree_add_text(rthdr_tree, tvb,
	    offset + offsetof(struct ip6_rthdr, ip6r_type), 1,
	    "Type: %u", rt.ip6r_type);
	proto_tree_add_text(rthdr_tree, tvb,
	    offset + offsetof(struct ip6_rthdr, ip6r_segleft), 1,
	    "Segments left: %u", rt.ip6r_segleft);

	if (rt.ip6r_type == 0 && len <= sizeof(buf)) {
	    struct e_in6_addr *a;
	    int n;
	    struct ip6_rthdr0 *rt0;

	    tvb_memcpy(tvb, buf, offset, len);
	    rt0 = (struct ip6_rthdr0 *)buf;
	    for (a = rt0->ip6r0_addr, n = 0;
		 a < (struct e_in6_addr *)(buf + len);
		 a++, n++) {
		proto_tree_add_text(rthdr_tree, tvb,
		    offset + offsetof(struct ip6_rthdr0, ip6r0_addr) + n * sizeof(struct e_in6_addr),
		    sizeof(struct e_in6_addr),
#ifdef INET6
		    "address %d: %s (%s)",
		    n, get_hostname6(a), ip6_to_str(a)
#else
		    "address %d: %s", n, ip6_to_str(a)
#endif
		    );
	    }
	}
  
	/* decode... */
    }

    return len;
}

static int
dissect_frag6(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree, 
    int *fragstart) {
    struct ip6_frag frag;
    int len;
    proto_item *ti;
    proto_tree *rthdr_tree;

    tvb_memcpy(tvb, (guint8 *)&frag, offset, sizeof(frag));
    len = sizeof(frag);
    frag.ip6f_offlg = ntohs(frag.ip6f_offlg);
    *fragstart = frag.ip6f_offlg & IP6F_OFF_MASK;
    if (check_col(pinfo->fd, COL_INFO)) {
	col_add_fstr(pinfo->fd, COL_INFO,
	    "IPv6 fragment (nxt=%s (0x%02x) off=%u id=0x%x)",
	    ipprotostr(frag.ip6f_nxt), frag.ip6f_nxt,
	    *fragstart, frag.ip6f_ident);
    }
    if (tree) {
	   ti = proto_tree_add_text(tree, tvb, offset, len,
			   "Fragmention Header");
	   rthdr_tree = proto_item_add_subtree(ti, ett_ipv6);

	   proto_tree_add_text(rthdr_tree, tvb,
			 offset + offsetof(struct ip6_frag, ip6f_nxt), 1,
			 "Next header: %s (0x%02x)",
			 ipprotostr(frag.ip6f_nxt), frag.ip6f_nxt);

	#if 0
	   proto_tree_add_text(rthdr_tree, tvb,
			 offset + offsetof(struct ip6_frag, ip6f_reserved), 1,
			 "Reserved: %u",
			 frag.ip6f_reserved);
	#endif

	   proto_tree_add_text(rthdr_tree, tvb,
			 offset + offsetof(struct ip6_frag, ip6f_offlg), 2,
			 "Offset: %u",
			 frag.ip6f_offlg & IP6F_OFF_MASK);

	   proto_tree_add_text(rthdr_tree, tvb,
			 offset + offsetof(struct ip6_frag, ip6f_offlg), 2,
			 "More fragments: %s",
				frag.ip6f_offlg & IP6F_MORE_FRAG ?
				"Yes" : "No");

	   proto_tree_add_text(rthdr_tree, tvb,
			 offset + offsetof(struct ip6_frag, ip6f_ident), 4,
			 "Identification: 0x%08x",
			 frag.ip6f_ident);
    }
    return len;
}

/* BT INSERT BEGIN */
static int
dissect_mipv6_ba(tvbuff_t *tvb, proto_tree *dstopt_tree, int offset) {
	guint8 status, len=0;
	gchar status_text[80]="";
	gboolean sub_options=FALSE;

	proto_tree_add_uint_format(dstopt_tree, hf_ipv6_mipv6_type, tvb, offset+len,
	IP6_MIPv6_OPTION_TYPE_LENGTH, tvb_get_guint8(tvb,offset+len),
	"Option Type: %u (0x%02x) - Binding Acknowledgement", tvb_get_guint8(tvb,offset+len),
	tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_OPTION_TYPE_LENGTH;
  if (tvb_get_guint8(tvb,offset+len)>11)
		sub_options=TRUE;
  proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_length, tvb, offset+len,
	IP6_MIPv6_OPTION_LENGTH_LENGTH, tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_OPTION_LENGTH_LENGTH;
	status = tvb_get_guint8(tvb,offset+len);
	switch (status){
		case BA_OK:
			strcpy(status_text,"- Binding Update accepted");
			break;
		case BA_REAS_UNSPEC:
			strcpy(status_text,"- Binding Update was rejected - Reason unspecified");
			break;
		case BA_ADMIN_PROH:
			strcpy(status_text,"- Binding Update was rejected - Administratively prohibited");
			break;
		case BA_INSUF_RES:
			strcpy(status_text,"- Binding Update was rejected - Insufficient resources");
			break;
		case BA_NO_HR:
			strcpy(status_text,"- Binding Update was rejected - Home registration not supported");
			break;
		case BA_NO_SUBNET:
			strcpy(status_text,"- Binding Update was rejected - Not home subnet");
			break;
		case BA_ERR_ID_LEN:
			strcpy(status_text,"- Binding Update was rejected - Incorrect interface identifier length");
			break;
		case BA_NO_HA:
			strcpy(status_text,"- Binding Update was rejected - Not home agent for this mobile node");
			break;
		case BA_DUPL_ADDR:
			strcpy(status_text,"- Binding Update was rejected - Duplicate Address Detection failed");
			break;
		default:
			strcpy(status_text,"");
			break;
	}
  if ((status>128)&&(strlen(status_text)==0))
		strcpy(status_text,"- Binding Update was rejected");
	proto_tree_add_uint_format(dstopt_tree, hf_ipv6_mipv6_status, tvb, offset+len,
	IP6_MIPv6_STATUS_LENGTH, tvb_get_guint8(tvb,offset+len),
	"Status: %u %s", tvb_get_guint8(tvb,offset+len), status_text);
  len+=IP6_MIPv6_STATUS_LENGTH;
  proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_sequence_number, tvb, offset+len,
	IP6_MIPv6_SEQUENCE_NUMBER_LENGTH, tvb_get_ntohs(tvb,offset+len));
  len+=IP6_MIPv6_SEQUENCE_NUMBER_LENGTH;
  if (tvb_get_ntohl(tvb,offset+len)==0xffffffff)
	{
		proto_tree_add_uint_format(dstopt_tree, hf_ipv6_mipv6_life_time, tvb, offset+len,
		IP6_MIPv6_LIFE_TIME_LENGTH, tvb_get_ntohl(tvb,offset+len),
		"Life Time: %u - Infinity", tvb_get_ntohl(tvb,offset+len));
	} else
	{
		proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_life_time, tvb, offset+len,
		IP6_MIPv6_LIFE_TIME_LENGTH, tvb_get_ntohl(tvb,offset+len));
  }
  len+=IP6_MIPv6_LIFE_TIME_LENGTH;
	proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_refresh, tvb, offset+len,
	IP6_MIPv6_REFRESH_LENGTH, tvb_get_ntohl(tvb,offset+len));
  len+=IP6_MIPv6_REFRESH_LENGTH;
  /* sub - options */
  if (sub_options)
  {
 		proto_tree_add_text(dstopt_tree, tvb, offset+len, 1, "Sub-Options");
	}
  return len;
}

static int
dissect_mipv6_bu(tvbuff_t *tvb, proto_tree *dstopt_tree, int offset) {
	int len=0;
	gboolean sub_options=FALSE;

	proto_tree_add_uint_format(dstopt_tree, hf_ipv6_mipv6_type, tvb, offset,
	IP6_MIPv6_OPTION_TYPE_LENGTH, tvb_get_guint8(tvb,offset),
	"Option Type: %u (0x%02x) - Binding Update", tvb_get_guint8(tvb,offset),
	tvb_get_guint8(tvb,offset));
  len+=IP6_MIPv6_OPTION_TYPE_LENGTH;
  if (tvb_get_guint8(tvb,offset+len)>8)
  sub_options=TRUE;
  proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_length, tvb, offset+len,
  IP6_MIPv6_OPTION_LENGTH_LENGTH, tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_OPTION_LENGTH_LENGTH;
  proto_tree_add_boolean(dstopt_tree, hf_ipv6_mipv6_a_flag, tvb, offset+len,
  IP6_MIPv6_FLAGS_LENGTH, tvb_get_guint8(tvb, offset+len));
  proto_tree_add_boolean(dstopt_tree, hf_ipv6_mipv6_h_flag, tvb, offset+len,
  IP6_MIPv6_FLAGS_LENGTH, tvb_get_guint8(tvb, offset+len));
  proto_tree_add_boolean(dstopt_tree, hf_ipv6_mipv6_r_flag, tvb, offset+len,
  IP6_MIPv6_FLAGS_LENGTH, tvb_get_guint8(tvb, offset+len));
  proto_tree_add_boolean(dstopt_tree, hf_ipv6_mipv6_d_flag, tvb, offset+len,
  IP6_MIPv6_FLAGS_LENGTH, tvb_get_guint8(tvb, offset+len));
  proto_tree_add_boolean(dstopt_tree, hf_ipv6_mipv6_m_flag, tvb, offset+len,
  IP6_MIPv6_FLAGS_LENGTH, tvb_get_guint8(tvb, offset+len));
  proto_tree_add_boolean(dstopt_tree, hf_ipv6_mipv6_b_flag, tvb, offset+len,
  IP6_MIPv6_FLAGS_LENGTH, tvb_get_guint8(tvb, offset+len));
  len+=IP6_MIPv6_FLAGS_LENGTH;
  proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_prefix_length, tvb, offset+len,
	IP6_MIPv6_PREFIX_LENGTH_LENGTH, tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_PREFIX_LENGTH_LENGTH;
  proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_sequence_number, tvb, offset+len,
	IP6_MIPv6_SEQUENCE_NUMBER_LENGTH, tvb_get_ntohs(tvb,offset+len));
  len+=IP6_MIPv6_SEQUENCE_NUMBER_LENGTH;
  if (tvb_get_ntohl(tvb,offset+len)==0xffffffff)
	{
		proto_tree_add_uint_format(dstopt_tree, hf_ipv6_mipv6_life_time, tvb, offset+len,
		IP6_MIPv6_LIFE_TIME_LENGTH, tvb_get_ntohl(tvb,offset+len),
		"Life Time: %u - Infinity", tvb_get_ntohl(tvb,offset+len));
	} else
	{
		proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_life_time, tvb, offset+len,
		IP6_MIPv6_LIFE_TIME_LENGTH, tvb_get_ntohl(tvb,offset+len));
  }
  len+=IP6_MIPv6_LIFE_TIME_LENGTH;
  /* sub - options */
  if (sub_options)
  {
 		proto_tree_add_text(dstopt_tree, tvb, offset+len, 1, "Sub-Options");
	}
  return len;
}

static int
dissect_mipv6_ha(tvbuff_t *tvb, proto_tree *dstopt_tree, int offset) {
	int len=0;
	gboolean sub_options=FALSE;

	proto_tree_add_uint_format(dstopt_tree, hf_ipv6_mipv6_type, tvb, offset+len,
	IP6_MIPv6_OPTION_TYPE_LENGTH, tvb_get_guint8(tvb,offset+len),
	"Option Type: %u (0x%02x) - Home Address", tvb_get_guint8(tvb,offset+len),
	tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_OPTION_TYPE_LENGTH;
  if (tvb_get_guint8(tvb,offset+len)>16)
		sub_options=TRUE;
  proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_length, tvb, offset+len,
	IP6_MIPv6_OPTION_LENGTH_LENGTH, tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_OPTION_LENGTH_LENGTH;
  proto_tree_add_ipv6(dstopt_tree, hf_ipv6_mipv6_home_address, tvb, offset+len,
	IP6_MIPv6_HOME_ADDRESS_LENGTH, tvb_get_ptr(tvb,offset+len,IP6_MIPv6_HOME_ADDRESS_LENGTH));
  len+=IP6_MIPv6_HOME_ADDRESS_LENGTH;						
  /* sub - options */
  if (sub_options)
  {
 		proto_tree_add_text(dstopt_tree, tvb, offset+len, 1, "Sub-Options");
	}
	return len;
}

static int
dissect_mipv6_br(tvbuff_t *tvb, proto_tree *dstopt_tree, int offset) {
	int len=0;	
	gboolean sub_options=FALSE;

	proto_tree_add_uint_format(dstopt_tree, hf_ipv6_mipv6_type, tvb, offset+len,
	IP6_MIPv6_OPTION_TYPE_LENGTH, tvb_get_guint8(tvb,offset+len),
	"Option Type: %u (0x%02x) - Binding Request", tvb_get_guint8(tvb,offset+len),
	tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_OPTION_TYPE_LENGTH;
  if (tvb_get_guint8(tvb,offset+len)>0)
		sub_options=TRUE;
  proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_length, tvb, offset+len,
	IP6_MIPv6_OPTION_LENGTH_LENGTH, tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_OPTION_LENGTH_LENGTH;
  /* sub - options */
  if (sub_options)
  {
 		proto_tree_add_text(dstopt_tree, tvb, offset+len, 1, "Sub-Options");
	}
	return len;
}

static int
dissect_mipv6_sub_u(tvbuff_t *tvb, proto_tree *dstopt_tree, int offset) {
	int len=0;
					
	proto_tree_add_uint_format(dstopt_tree, hf_ipv6_mipv6_sub_length, tvb, offset+len,
	IP6_MIPv6_SUB_TYPE_LENGTH, tvb_get_guint8(tvb,offset+len),
	"Sub-Option Type: %u (0x%02x) - Unique Identifier Sub-Option", tvb_get_guint8(tvb,offset+len),
	tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_SUB_TYPE_LENGTH;
  proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_sub_length, tvb, offset+len,
	IP6_MIPv6_SUB_LENGTH_LENGTH, tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_SUB_LENGTH_LENGTH;
  proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_sub_unique_ID, tvb, offset+len,
	IP6_MIPv6_SUB_UNIQUE_ID_LENGTH, tvb_get_ntohs(tvb,offset+len));
  len+=IP6_MIPv6_SUB_UNIQUE_ID_LENGTH;						
	return len;
}

static int
dissect_mipv6_sub_a_coa(tvbuff_t *tvb, proto_tree *dstopt_tree, int offset) {
	int len=0;

	proto_tree_add_uint_format(dstopt_tree, hf_ipv6_mipv6_sub_type, tvb, offset+len,
	IP6_MIPv6_SUB_TYPE_LENGTH, tvb_get_guint8(tvb,offset+len),
	"Sub-Option Type: %u (0x%02x) - Alternative Care Of Address", tvb_get_guint8(tvb,offset+len),
	tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_SUB_TYPE_LENGTH;
  proto_tree_add_uint(dstopt_tree, hf_ipv6_mipv6_sub_length, tvb, offset+len,
	IP6_MIPv6_SUB_LENGTH_LENGTH, tvb_get_guint8(tvb,offset+len));
  len+=IP6_MIPv6_SUB_LENGTH_LENGTH;
  proto_tree_add_ipv6(dstopt_tree, hf_ipv6_mipv6_sub_alternative_COA, tvb, offset+len,
	IP6_MIPv6_SUB_ALTERNATIVE_COA_LENGTH, tvb_get_ptr(tvb,offset+len,IP6_MIPv6_SUB_ALTERNATIVE_COA_LENGTH));
  len+=IP6_MIPv6_SUB_ALTERNATIVE_COA_LENGTH;						
	return len;
}
/* BT INSERT END */

static int
dissect_opts(tvbuff_t *tvb, int offset, proto_tree *tree,
  char *optname) {
	struct ip6_ext ext;
  int len;
  proto_tree *dstopt_tree;
	proto_item *ti;
  gint p;
  guint8 tmp;

	/* BT INSERT BEGIN */
#if 0
	tvbuff_t *tvb;
#endif
  int mip_offset=0, delta=0;
  /* BT INSERT END */

  static const value_string rtalertvals[] = {
	{ IP6OPT_RTALERT_MLD, "MLD" },
	{ IP6OPT_RTALERT_RSVP, "RSVP" },
	{ 0, NULL },
    };

  tvb_memcpy(tvb, (guint8 *)&ext, offset, sizeof(ext));
  len = (ext.ip6e_len + 1) << 3;

  /* BT INSERT BEGIN */
#if 0
	tvb = tvb_create_from_top(offset);
#endif
  /* BT INSERT END */

	if (tree) {
		/* !!! specify length */
		ti = proto_tree_add_text(tree, tvb, offset, len,
	    "%s Header ", optname);

		dstopt_tree = proto_item_add_subtree(ti, ett_ipv6);

		proto_tree_add_text(dstopt_tree, tvb,
		offset + offsetof(struct ip6_ext, ip6e_nxt), 1,
	  "Next header: %s (0x%02x)", ipprotostr(ext.ip6e_nxt),ext.ip6e_nxt);
    proto_tree_add_text(dstopt_tree, tvb,
		offset + offsetof(struct ip6_ext, ip6e_len), 1,
	  "Length: %u (%d bytes)", ext.ip6e_len, len);

    /* BT INSERT BEGIN */
    mip_offset=offset;
    mip_offset+=2;
    /* BT INSERT END */

		p = offset + 2;

		while (p < offset + len) {
	  	switch (tvb_get_guint8(tvb, p)) {
	    	case IP6OPT_PAD1:
					proto_tree_add_text(dstopt_tree, tvb, p, 1,
		    	"Pad1");
					p++;
          /* BT INSERT BEGIN */
					mip_offset++;
          /* BT INSERT END */
					break;
	    	case IP6OPT_PADN:
					tmp = tvb_get_guint8(tvb, p + 1);
					proto_tree_add_text(dstopt_tree, tvb, p, tmp + 2,
		    	"PadN: %u bytes", tmp + 2);
					p += tmp;
					p += 2;
          /* BT INSERT BEGIN */
					mip_offset+=tvb_get_guint8(tvb,mip_offset+1)+2;
          /* BT INSERT END */
					break;
	    	case IP6OPT_JUMBO:
					tmp = tvb_get_guint8(tvb, p + 1);
					if (tmp == 4) {
		    		proto_tree_add_text(dstopt_tree, tvb, p, tmp + 2,
						"Jumbo payload: %u (%u bytes)",
						tvb_get_ntohl(tvb, p + 2), tmp + 2);
					} else {
		    		proto_tree_add_text(dstopt_tree, tvb, p, tmp + 2,
						"Jumbo payload: Invalid length (%u bytes)",
						tmp + 2);
					}
					p += tmp;
					p += 2;
          /* BT INSERT BEGIN */
					mip_offset+=tvb_get_guint8(tvb,mip_offset+1)+2;
          /* BT INSERT END */
					break;
	    	case IP6OPT_RTALERT:
	      	{
					char *rta;

					tmp = tvb_get_guint8(tvb, p + 1);
					if (tmp == 2) {
		    		rta = val_to_str(tvb_get_ntohs(tvb, p + 2), rtalertvals,
						"Unknown");
					} else
		    		rta = "Invalid length";
					ti = proto_tree_add_text(dstopt_tree, tvb, p , tmp + 2,
		    			"Router alert: %s (%u bytes)", rta, tmp + 2);
					p += tmp;
					p += 2;
					/* BT INSERT BEGIN */
					mip_offset+=tvb_get_guint8(tvb,mip_offset+1)+2;
          /* BT INSERT END */
					break;
	      	}
        /* BT INSERT BEGIN */
  			case IP6OPT_BINDING_UPDATE :
       	 	{     	
            delta=dissect_mipv6_bu(tvb, dstopt_tree, mip_offset);
						p+=delta;
						mip_offset+=delta;
        		break;
       		}
  			case IP6OPT_BINDING_ACK :
       	 	{			
            delta=dissect_mipv6_ba(tvb, dstopt_tree, mip_offset);
						p+=delta;
						mip_offset+=delta;
						break;			
					}
  			case IP6OPT_HOME_ADDRESS :
       	 	{
            delta=dissect_mipv6_ha(tvb, dstopt_tree, mip_offset);
						p+=delta;
						mip_offset+=delta;
						break;			
          }
  			case IP6OPT_BINDING_REQUEST :
       	 	{
	          delta=dissect_mipv6_br(tvb, dstopt_tree, mip_offset);
						p+=delta;
						mip_offset+=delta;
						break;
					}
  			case IP6OPT_MIPv6_UNIQUE_ID_SUB :
       	 	{
	          delta=dissect_mipv6_sub_u(tvb, dstopt_tree, mip_offset);
						p+=delta;
						mip_offset+=delta;
						break;
					}
  			case IP6OPT_MIPv6_ALTERNATIVE_COA_SUB :
       	 	{
	          delta=dissect_mipv6_sub_a_coa(tvb, dstopt_tree, mip_offset);
						p+=delta;
						mip_offset+=delta;
						break;
					}
        /* BT INSERT END */
	    	default:
					p = offset + len;
					break;
	   	}
		}

	/* decode... */

	}
    return len;
}

static int
dissect_hopopts(tvbuff_t *tvb, int offset, proto_tree *tree) {
    return dissect_opts(tvb, offset, tree, "Hop-by-hop Option");
}

static int
dissect_dstopts(tvbuff_t *tvb, int offset, proto_tree *tree) {
    return dissect_opts(tvb, offset, tree, "Destination Option");
}

void
dissect_ipv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
  proto_tree *ipv6_tree;
  proto_item *ti;
  guint8 nxt;
  int advance;
  int poffset;
  int frag;
  int offset;

  struct ip6_hdr ipv6;

  CHECK_DISPLAY_AS_DATA(proto_ipv6, tvb, pinfo, tree);

  offset = 0;
  tvb_memcpy(tvb, (guint8 *)&ipv6, offset, sizeof(ipv6)); 

  pinfo->ipproto = ipv6.ip6_nxt; /* XXX make work TCP follow (ipproto = 6) */

  /* Check for trailer (not part of IPv6 packet) */
  if (pntohs(&ipv6.ip6_plen) + sizeof (struct ip6_hdr) < tvb_reported_length(tvb))
    tvb_set_reported_length(tvb, pntohs(&ipv6.ip6_plen) + sizeof (struct ip6_hdr));

  SET_ADDRESS(&pinfo->net_src, AT_IPv6, 16, tvb_get_ptr(tvb, offset + IP6H_SRC, 16));
  SET_ADDRESS(&pinfo->src, AT_IPv6, 16, tvb_get_ptr(tvb, offset + IP6H_SRC, 16));
  SET_ADDRESS(&pinfo->net_dst, AT_IPv6, 16, tvb_get_ptr(tvb, offset + IP6H_DST, 16));
  SET_ADDRESS(&pinfo->dst, AT_IPv6, 16, tvb_get_ptr(tvb, offset + IP6H_DST, 16));

  if (tree) {
    /* !!! specify length */
    ti = proto_tree_add_item(tree, proto_ipv6, tvb, offset, 40, FALSE);
    ipv6_tree = proto_item_add_subtree(ti, ett_ipv6);

    /* !!! warning: version also contains 4 Bit priority */
    proto_tree_add_uint(ipv6_tree, hf_ipv6_version, tvb,
		offset + offsetof(struct ip6_hdr, ip6_vfc), 1,
		(ipv6.ip6_vfc >> 4) & 0x0f);


    proto_tree_add_uint(ipv6_tree, hf_ipv6_class, tvb,
		offset + offsetof(struct ip6_hdr, ip6_flow), 4,
		(guint8)((ntohl(ipv6.ip6_flow) >> 20) & 0xff));

    /*
     * there should be no alignment problems for ip6_flow, since it's the first
     * guint32 in the ipv6 struct
     */
    proto_tree_add_uint_format(ipv6_tree, hf_ipv6_flow, tvb,
		offset + offsetof(struct ip6_hdr, ip6_flow), 4,
		(unsigned long)(ntohl(ipv6.ip6_flow) & IPV6_FLOWLABEL_MASK),
		"Flowlabel: 0x%05lx",
		(unsigned long)(ntohl(ipv6.ip6_flow) & IPV6_FLOWLABEL_MASK));

    proto_tree_add_uint(ipv6_tree, hf_ipv6_plen, tvb,
		offset + offsetof(struct ip6_hdr, ip6_plen), 2,
		ntohs(ipv6.ip6_plen));

    proto_tree_add_uint_format(ipv6_tree, hf_ipv6_nxt, tvb,
		offset + offsetof(struct ip6_hdr, ip6_nxt), 1,
		ipv6.ip6_nxt,
		"Next header: %s (0x%02x)",
		ipprotostr(ipv6.ip6_nxt), ipv6.ip6_nxt);

    proto_tree_add_uint(ipv6_tree, hf_ipv6_hlim, tvb,
		offset + offsetof(struct ip6_hdr, ip6_hlim), 1,
		ipv6.ip6_hlim);

    proto_tree_add_ipv6_hidden(ipv6_tree, hf_ipv6_addr, tvb, 
			       offset + offsetof(struct ip6_hdr, ip6_src), 16,
			       ipv6.ip6_src.s6_addr8);
    proto_tree_add_ipv6_hidden(ipv6_tree, hf_ipv6_addr, tvb, 
			       offset + offsetof(struct ip6_hdr, ip6_dst), 16,
			       ipv6.ip6_dst.s6_addr8);

    proto_tree_add_ipv6_format(ipv6_tree, hf_ipv6_src, tvb,
		offset + offsetof(struct ip6_hdr, ip6_src), 16,
		(guint8 *)&ipv6.ip6_src,
#ifdef INET6
		"Source address: %s (%s)",
		get_hostname6(&ipv6.ip6_src),
#else
		"Source address: %s",
#endif
		ip6_to_str(&ipv6.ip6_src));

    proto_tree_add_ipv6_format(ipv6_tree, hf_ipv6_dst, tvb,
		offset + offsetof(struct ip6_hdr, ip6_dst), 16,
		(guint8 *)&ipv6.ip6_dst,
#ifdef INET6
		"Destination address: %s (%s)",
		get_hostname6(&ipv6.ip6_dst),
#else
		"Destination address: %s",
#endif
		ip6_to_str(&ipv6.ip6_dst));
  }

  /* start of the new header (could be a extension header) */
  poffset = offset + offsetof(struct ip6_hdr, ip6_nxt);
  nxt = tvb_get_guint8(tvb, poffset);
  offset += sizeof(struct ip6_hdr);
  frag = 0;

/* start out assuming this insn't fragmented */
	pinfo->fragmented = FALSE;

again:
    switch (nxt) {
    case IP_PROTO_HOPOPTS:
			advance = dissect_hopopts(tvb, offset, tree);
			nxt = tvb_get_guint8(tvb, offset);
			poffset = offset;
			offset += advance;
			goto again;
    case IP_PROTO_ROUTING:
			advance = dissect_routing6(tvb, offset, tree);
			nxt = tvb_get_guint8(tvb, offset);
			poffset = offset;
			offset += advance;
			goto again;
    case IP_PROTO_FRAGMENT:
			pinfo->fragmented = TRUE;
			advance = dissect_frag6(tvb, offset, pinfo, tree, &frag);
			nxt = tvb_get_guint8(tvb, offset);
			poffset = offset;
			offset += advance;
			goto again;
    case IP_PROTO_AH:
			advance = dissect_ah_header(
				  tvb_new_subset(tvb, offset, -1, -1),
				  pinfo, tree, NULL, NULL);
			nxt = tvb_get_guint8(tvb, offset);
			poffset = offset;
			offset += advance;
			goto again;
    case IP_PROTO_DSTOPTS:
			advance = dissect_dstopts(tvb, offset, tree);
			nxt = tvb_get_guint8(tvb, offset);
			poffset = offset;
			offset += advance;
			goto again;
    }

#ifdef TEST_FINALHDR
  proto_tree_add_uint_hidden(ipv6_tree, hf_ipv6_final, tvb, poffset, 1, nxt);
#endif
  if (frag) {
    /* fragmented */
    if (check_col(pinfo->fd, COL_PROTOCOL))
      col_set_str(pinfo->fd, COL_PROTOCOL, "IPv6");
    /* COL_INFO was filled in by "dissect_frag6()" */
    dissect_data(tvb, offset, pinfo, tree);
  }	else {
    tvbuff_t *next_tvb = tvb_new_subset(tvb, offset, -1, -1);

    /* do lookup with the subdissector table */
    if (!dissector_try_port(ip_dissector_table, nxt, next_tvb, pinfo, tree)) {
      /* Unknown protocol */
      if (check_col(pinfo->fd, COL_PROTOCOL))
	col_set_str(pinfo->fd, COL_PROTOCOL, "IPv6");
      if (check_col(pinfo->fd, COL_INFO))
	col_add_fstr(pinfo->fd, COL_INFO, "%s (0x%02x)", ipprotostr(nxt),nxt);
      dissect_data(next_tvb, 0, pinfo, tree);
    }
  }
}

static void
dissect_ipv6_none(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
  /* BT INSERT BEGIN */
  if (hf_ipv6_mipv6_length!=-1) {
  	if (check_col(pinfo->fd, COL_PROTOCOL))
    	col_set_str(pinfo->fd, COL_PROTOCOL, "IPv6");
  	if (check_col(pinfo->fd, COL_INFO))
    	col_add_fstr(pinfo->fd, COL_INFO, "MobileIPv6 Destination Option");
	} else {
  /* BT INSERT END */
  if (check_col(pinfo->fd, COL_INFO))
    col_add_fstr(pinfo->fd, COL_INFO, "IPv6 no next header");
  }
  /* XXX - dissect the payload as padding? */
}

void
proto_register_ipv6(void)
{
  static hf_register_info hf[] = {
    { &hf_ipv6_version,
      { "Version",		"ipv6.version",
				FT_UINT8, BASE_DEC, NULL, 0x0, "" }},
    { &hf_ipv6_class,
      { "Traffic class",	"ipv6.class",
				FT_UINT8, BASE_HEX, NULL, 0x0, "" }},
    { &hf_ipv6_flow,
      { "Flowlabel",		"ipv6.flow",
				FT_UINT32, BASE_HEX, NULL, 0x0, "" }},
    { &hf_ipv6_plen,
      { "Payload length",	"ipv6.plen",
				FT_UINT16, BASE_DEC, NULL, 0x0, "" }},
    { &hf_ipv6_nxt,
      { "Next header",		"ipv6.nxt",
				FT_UINT8, BASE_HEX, NULL, 0x0, "" }},
    { &hf_ipv6_hlim,
      { "Hop limit",		"ipv6.hlim",
				FT_UINT8, BASE_DEC, NULL, 0x0, "" }},
    { &hf_ipv6_src,
      { "Source",		"ipv6.src",
				FT_IPv6, BASE_NONE, NULL, 0x0,
				"Source IPv6 Address" }},
    { &hf_ipv6_dst,
      { "Destination",		"ipv6.dst",
				FT_IPv6, BASE_NONE, NULL, 0x0,
				"Destination IPv6 Address" }},
    { &hf_ipv6_addr,
      { "Address",		"ipv6.addr",
				FT_IPv6, BASE_NONE, NULL, 0x0,
				"Source or Destination IPv6 Address" }},

    /* BT INSERT BEGIN */
    { &hf_ipv6_mipv6_type,
      { "Option Type ",		"ipv6.mipv6_type",
				FT_UINT8, BASE_DEC, NULL, 0x0,
				"" }},
    { &hf_ipv6_mipv6_length,
      { "Option Length ",		"ipv6.mipv6_length",
				FT_UINT8, BASE_DEC, NULL, 0x0,
				"" }},
    { &hf_ipv6_mipv6_a_flag,
      { "Acknowledge (A) ",		"ipv6.mipv6_a_flag",
				FT_BOOLEAN, 8, TFS(&ipv6_mipv6_bu_a_flag_value),
				IP6_MIPv6_BU_A_FLAG,
				"" }},
    { &hf_ipv6_mipv6_h_flag,
      { "Home Registration (H) ",		"ipv6.mipv6_h_flag",
				FT_BOOLEAN, 8, TFS(&ipv6_mipv6_bu_h_flag_value),
				IP6_MIPv6_BU_H_FLAG,
				"" }},
    { &hf_ipv6_mipv6_r_flag,
      { "Router (R) ",		"ipv6.mipv6_r_flag",
				FT_BOOLEAN, 8, TFS(&ipv6_mipv6_bu_r_flag_value),
				IP6_MIPv6_BU_R_FLAG,
				"" }},
    { &hf_ipv6_mipv6_d_flag,
      { "Duplicate Address Detection (D) ",		"ipv6.mipv6_d_flag",
				FT_BOOLEAN, 8, TFS(&ipv6_mipv6_bu_d_flag_value),
				IP6_MIPv6_BU_D_FLAG,
				"" }},
    { &hf_ipv6_mipv6_m_flag,
      { "MAP Registration (M) ",		"ipv6.mipv6_m_flag",
				FT_BOOLEAN, 8, TFS(&ipv6_mipv6_bu_m_flag_value),
				IP6_MIPv6_BU_M_FLAG,
				"" }},
    { &hf_ipv6_mipv6_b_flag,
      { "Bicasting all (B) ",		"ipv6.mipv6_b_flag",
				FT_BOOLEAN, 8, TFS(&ipv6_mipv6_bu_b_flag_value),
				IP6_MIPv6_BU_B_FLAG,
				"" }},
    { &hf_ipv6_mipv6_prefix_length,
      { "Prefix Length ",		"ipv6.mipv6_prefix_length",
				FT_UINT8, BASE_DEC, NULL, 0x0,
				"" }},
    { &hf_ipv6_mipv6_sequence_number,
      { "Sequence Number ",		"ipv6.mipv6_sequence_number",
				FT_UINT16, BASE_DEC, NULL, 0x0,
				"" }},
    { &hf_ipv6_mipv6_life_time,
      { "Life Time ",		"ipv6.mipv6_life_time",
				FT_UINT32, BASE_DEC, NULL, 0x0,
				"" }},
    { &hf_ipv6_mipv6_status,
      { "Status ",		"ipv6.mipv6_status",
				FT_UINT8, BASE_DEC, NULL, 0x0,
				"" }},
    { &hf_ipv6_mipv6_refresh,
      { "Refresh ",		"ipv6.mipv6_refresh",
				FT_UINT32, BASE_DEC, NULL, 0x0,
				"" }},
    { &hf_ipv6_mipv6_home_address,
      { "Home Address ",		"ipv6.mipv6_home_address",
				FT_IPv6, BASE_HEX, NULL, 0x0,
				"" }},
    { &hf_ipv6_mipv6_sub_type,
      { "Sub-Option Type ",		"ipv6.mipv6_sub_type",
				FT_UINT8, BASE_DEC, NULL, 0x0,
				"" }},
    { &hf_ipv6_mipv6_sub_length,
      { "Sub-Option Length ",		"ipv6.mipv6_sub_length",
				FT_UINT8, BASE_DEC, NULL, 0x0,
				"" }},
    { &hf_ipv6_mipv6_sub_unique_ID,
      { "Unique Identifier ",		"ipv6.mipv6_sub_unique_ID",
				FT_UINT16, BASE_DEC, NULL, 0x0,
				"" }},
    { &hf_ipv6_mipv6_sub_alternative_COA,
      { "Alternative Care of Address ",		"ipv6.mipv6_sub_alternative_COA",
				FT_IPv6, BASE_HEX, NULL, 0x0,
				"" }},

    /* BT INSERT END */
#ifdef TEST_FINALHDR
    { &hf_ipv6_final,
      { "Final next header",	"ipv6.final",
				FT_UINT8, BASE_HEX, NULL, 0x0, "" }},
#endif
  };
  static gint *ett[] = {
    &ett_ipv6,
  };

  proto_ipv6 = proto_register_protocol("Internet Protocol Version 6", "IPv6", "ipv6");
  proto_register_field_array(proto_ipv6, hf, array_length(hf));
  proto_register_subtree_array(ett, array_length(ett));
}

void
proto_reg_handoff_ipv6(void)
{
	dissector_add("ethertype", ETHERTYPE_IPv6, dissect_ipv6, proto_ipv6);
	dissector_add("ppp.protocol", PPP_IPV6, dissect_ipv6, proto_ipv6);
	dissector_add("ip.proto", IP_PROTO_IPV6, dissect_ipv6, proto_ipv6);
	dissector_add("null.type", BSD_AF_INET6_BSD, dissect_ipv6, proto_ipv6);
	dissector_add("null.type", BSD_AF_INET6_FREEBSD, dissect_ipv6, proto_ipv6);
	dissector_add("ip.proto", IP_PROTO_NONE, dissect_ipv6_none, proto_ipv6);
}