epan/dissectors/packet-raw.c

   1 /* packet-raw.c
   2  * Routines for raw packet disassembly
   3  *
   4  * $Id$
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  *
   9  * This file created and by Mike Hall <mlh@io.com>
  10  * Copyright 1998
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  25  */
  26
  27 #include "config.h"
  28
  29 #include <string.h>
  30 #include <glib.h>
  31 #include <epan/packet.h>
  32 #include <epan/prefs.h>
  33 #include "packet-raw.h"
  34 #include "packet-ip.h"
  35 #include "packet-ppp.h"
  36
  37 static int proto_raw = -1;
  38 static gint ett_raw = -1;
  39
  40 static const char zeroes[10] = {0,0,0,0,0,0,0,0,0,0};
  41
  42 static dissector_handle_t ip_handle;
  43 static dissector_handle_t ipv6_handle;
  44 static dissector_handle_t data_handle;
  45 static dissector_handle_t ppp_hdlc_handle;
  46
  47 void
  48 capture_raw(const guchar *pd, int len, packet_counts *ld)
  49 {
  50   /* So far, the only time we get raw connection types are with Linux and
  51    * Irix PPP connections.  We can't tell what type of data is coming down
  52    * the line, so our safest bet is IP. - GCC
  53    */
  54
  55   /* Currently, the Linux 2.1.xxx PPP driver passes back some of the header
  56    * sometimes.  This check should be removed when 2.2 is out.
  57    */
  58   if (BYTES_ARE_IN_FRAME(0,len,2) && pd[0] == 0xff && pd[1] == 0x03) {
  59     capture_ppp_hdlc(pd, 0, len, ld);
  60   }
  61   /* The Linux ISDN driver sends a fake MAC address before the PPP header
  62    * on its ippp interfaces... */
  63   else if (BYTES_ARE_IN_FRAME(0,len,8) && pd[6] == 0xff && pd[7] == 0x03) {
  64     capture_ppp_hdlc(pd, 6, len, ld);
  65   }
  66   /* ...except when it just puts out one byte before the PPP header... */
  67   else if (BYTES_ARE_IN_FRAME(0,len,3) && pd[1] == 0xff && pd[2] == 0x03) {
  68     capture_ppp_hdlc(pd, 1, len, ld);
  69   }
  70   /* ...and if the connection is currently down, it sends 10 bytes of zeroes
  71    * instead of a fake MAC address and PPP header. */
  72   else if (BYTES_ARE_IN_FRAME(0,len,10) && memcmp(pd, zeroes, 10) == 0) {
  73     capture_ip(pd, 10, len, ld);
  74   }
  75   else {
  76     /*
  77      * OK, is this IPv4 or IPv6?
  78      */
  79     if (BYTES_ARE_IN_FRAME(0,len,1)) {
  80       switch (pd[0] & 0xF0) {
  81
  82       case 0x40:
  83         /* IPv4 */
  84         capture_ip(pd, 0, len, ld);
  85         break;
  86
  87 #if 0
  88       case 0x60:
  89         /* IPv6 */
  90         capture_ipv6(pd, 0, len, ld);
  91         break;
  92 #endif
  93       }
  94     }
  95   }
  96 }
  97
  98 static void
  99 dissect_raw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 100 {
 101   proto_tree    *fh_tree;
 102   proto_item    *ti;
 103   tvbuff_t      *next_tvb;
 104
 105   /* load the top pane info. This should be overwritten by
 106      the next protocol in the stack */
 107   col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "N/A");
 108   col_set_str(pinfo->cinfo, COL_RES_DL_DST, "N/A");
 109   col_set_str(pinfo->cinfo, COL_PROTOCOL, "N/A");
 110   col_set_str(pinfo->cinfo, COL_INFO, "Raw packet data");
 111
 112   /* populate a tree in the second pane with the status of the link
 113      layer (ie none) */
 114   if (tree) {
 115     ti = proto_tree_add_item(tree, proto_raw, tvb, 0, 0, ENC_NA);
 116     fh_tree = proto_item_add_subtree(ti, ett_raw);
 117     proto_tree_add_text(fh_tree, tvb, 0, 0, "No link information available");
 118   }
 119
 120   if (pinfo->fd->lnk_t == WTAP_ENCAP_RAW_IP4) {
 121     call_dissector(ip_handle, tvb, pinfo, tree);
 122   }
 123   else if (pinfo->fd->lnk_t == WTAP_ENCAP_RAW_IP6) {
 124     call_dissector(ipv6_handle, tvb, pinfo, tree);
 125   }
 126   else
 127
 128   /* So far, the only time we get raw connection types are with Linux and
 129    * Irix PPP connections.  We can't tell what type of data is coming down
 130    * the line, so our safest bet is IP. - GCC
 131    */
 132
 133   /* Currently, the Linux 2.1.xxx PPP driver passes back some of the header
 134    * sometimes.  This check should be removed when 2.2 is out.
 135    */
 136   if (tvb_get_ntohs(tvb, 0) == 0xff03) {
 137         call_dissector(ppp_hdlc_handle, tvb, pinfo, tree);
 138   }
 139   /* The Linux ISDN driver sends a fake MAC address before the PPP header
 140    * on its ippp interfaces... */
 141   else if (tvb_get_ntohs(tvb, 6) == 0xff03) {
 142         next_tvb = tvb_new_subset_remaining(tvb, 6);
 143         call_dissector(ppp_hdlc_handle, next_tvb, pinfo, tree);
 144   }
 145   /* ...except when it just puts out one byte before the PPP header... */
 146   else if (tvb_get_ntohs(tvb, 1) == 0xff03) {
 147         next_tvb = tvb_new_subset_remaining(tvb, 1);
 148         call_dissector(ppp_hdlc_handle, next_tvb, pinfo, tree);
 149   }
 150   /* ...and if the connection is currently down, it sends 10 bytes of zeroes
 151    * instead of a fake MAC address and PPP header. */
 152   else if (tvb_memeql(tvb, 0, zeroes,10) == 0) {
 153         next_tvb = tvb_new_subset_remaining(tvb, 10);
 154         call_dissector(ip_handle, next_tvb, pinfo, tree);
 155   }
 156   else {
 157         /*
 158          * OK, is this IPv4 or IPv6?
 159          */
 160         switch (tvb_get_guint8(tvb, 0) & 0xF0) {
 161
 162         case 0x40:
 163           /* IPv4 */
 164           call_dissector(ip_handle, tvb, pinfo, tree);
 165           break;
 166
 167         case 0x60:
 168           /* IPv6 */
 169           call_dissector(ipv6_handle, tvb, pinfo, tree);
 170           break;
 171
 172         default:
 173           /* None of the above. */
 174           call_dissector(data_handle, tvb, pinfo, tree);
 175           break;
 176         }
 177   }
 178 }
 179
 180 void
 181 proto_register_raw(void)
 182 {
 183   static gint *ett[] = {
 184     &ett_raw,
 185   };
 186
 187   proto_raw = proto_register_protocol("Raw packet data", "Raw", "raw");
 188   proto_register_subtree_array(ett, array_length(ett));
 189 }
 190
 191 void
 192 proto_reg_handoff_raw(void)
 193 {
 194   dissector_handle_t raw_handle;
 195
 196   /*
 197    * Get handles for the IP, IPv6, undissected-data, and
 198    * PPP-in-HDLC-like-framing dissectors.
 199    */
 200   ip_handle = find_dissector("ip");
 201   ipv6_handle = find_dissector("ipv6");
 202   data_handle = find_dissector("data");
 203   ppp_hdlc_handle = find_dissector("ppp_hdlc");
 204   raw_handle = create_dissector_handle(dissect_raw, proto_raw);
 205   dissector_add_uint("wtap_encap", WTAP_ENCAP_RAW_IP, raw_handle);
 206   dissector_add_uint("wtap_encap", WTAP_ENCAP_RAW_IP4, raw_handle);
 207   dissector_add_uint("wtap_encap", WTAP_ENCAP_RAW_IP6, raw_handle);
 208 }