epan/dissectors/packet-pw-hdlc.c

   1 /* packet-pw-hdlc.c
   2  * Routines for HDLC PW dissection as per RFC4618.
   3  * Copyright 2009, Dmitry Trebich, Artem Tamazov <artem.tamazov@tellabs.com>
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  *
  25  * History:
  26  * ---------------------------------
  27  * 02.03.2009 Initial implementation, supports:
  28  * - HDLC mode (rfc4618 5.1), no CW, payload is PPP (PPP in HDLC-like Framing (rfc1662)).
  29  * - FR port mode (rfc4618 5.2), no CW.
  30  *
  31  * [informative: Not supported yet:
  32  * - All kinds of HDLC PW with CW.
  33  * - PPP mode (rfc4618 5.3).
  34  * - For HDLC mode, decoding payloads other than PPP.]
  35  */
  36
  37 #ifdef HAVE_CONFIG_H
  38 # include "config.h"
  39 #endif
  40
  41 #include <stdlib.h>
  42 #include <glib.h>
  43 #include <epan/packet.h>
  44
  45 #include "packet-mpls.h"
  46
  47 static dissector_handle_t ppp_handle;
  48 static dissector_handle_t fr_handle;
  49
  50 static gint proto_pw_hdlc_nocw_fr = -1;
  51 static gint proto_pw_hdlc_nocw_hdlc_ppp = -1;
  52
  53 static gint ett_pw_hdlc = -1;
  54
  55 static int hf_pw_hdlc = -1;
  56 static int hf_pw_hdlc_address_field = -1;
  57 static int hf_pw_hdlc_address = -1;
  58 static int hf_pw_hdlc_cr_bit = -1;
  59 static int hf_pw_hdlc_control_field = -1;
  60 static int hf_pw_hdlc_pf_bit = -1;
  61
  62 static void dissect_pw_hdlc_nocw_fr( tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree )
  63 {
  64         call_dissector( fr_handle, tvb, pinfo, tree );
  65 }
  66
  67
  68 static void dissect_pw_hdlc_nocw_hdlc_ppp( tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree )
  69 {
  70         if (tvb_reported_length_remaining(tvb, 0) < 2)
  71         {
  72                 if (tree)
  73                 {
  74                         proto_tree_add_text(tree, tvb, 0, -1, "Error processing message");
  75                 }
  76                 return;
  77         }
  78
  79         if (tree)
  80         {
  81                 proto_tree  *tr;
  82                 proto_item  *item;
  83                 proto_item  *item_address;
  84                 proto_item  *item_control;
  85                 guint8      addr;
  86                 guint8      control;
  87
  88                 addr    = tvb_get_guint8(tvb, 0);
  89                 control = tvb_get_guint8(tvb, 1);
  90
  91                 item = proto_tree_add_item( tree, proto_pw_hdlc_nocw_hdlc_ppp, tvb, 0, 2, FALSE );
  92
  93                 tr = proto_item_add_subtree( item, ett_pw_hdlc );
  94
  95                 item_address = proto_tree_add_uint( tr, hf_pw_hdlc_address_field, tvb, 0, 1, addr );
  96                 item_control = proto_tree_add_uint_format( tr, hf_pw_hdlc_control_field, tvb, 1, 1, control, "Control field: 0x%x", control );
  97
  98                 tr = proto_item_add_subtree( item_address, ett_pw_hdlc );
  99
 100                 if ( 0x3F == (( addr & 0xFC ) >> 2 ))
 101                         proto_tree_add_uint_format( tr, hf_pw_hdlc_address, tvb, 0, 1, 0xFC, "Address: 0x%x (All stations)", 0x3F );
 102                 else
 103                         proto_tree_add_uint( tr, hf_pw_hdlc_address, tvb, 0, 1, ( addr & 0xFC ) >> 2 );
 104
 105                 proto_tree_add_uint( tr, hf_pw_hdlc_cr_bit, tvb, 0, 1, ( addr & 2 ) >> 1 );
 106
 107                 tr = proto_item_add_subtree( item_control, ett_pw_hdlc );
 108
 109                 if ( control & 1 )
 110                 {
 111                         if ( control & 2 )
 112                         {
 113                                 guint8 modifier2;
 114                                 guint8 modifier3;
 115
 116                                 proto_tree_add_text( tr, tvb, 1, 1, "U frame" );
 117
 118                                 proto_tree_add_uint( tr, hf_pw_hdlc_pf_bit, tvb, 1, 1, ( control & 0x10 ) >> 4 );
 119
 120                                 modifier2 = (( control & 0xC ) >> 2 );
 121                                 modifier3 = (( control & 0xE0 ) >> 5 );
 122
 123                                 /**/ if ( modifier2 == 0 && modifier3 == 0 )
 124                                         proto_tree_add_text( tr, tvb, 1, 1,
 125                                                 "Modifier: UI - Unnumbered information" );
 126                                 else if ( modifier2 == 0 && modifier3 == 1 )
 127                                         proto_tree_add_text( tr, tvb, 1, 1,
 128                                                 "Modifier: UP - Unnumbered poll" );
 129                                 else if ( modifier2 == 0 && modifier3 == 2 )
 130                                         proto_tree_add_text( tr, tvb, 1, 1,
 131                                                 "Modifier: DISC/RD - Disconnect/Request disconnect" );
 132                                 else if ( modifier2 == 0 && modifier3 == 3 )
 133                                         proto_tree_add_text( tr, tvb, 1, 1,
 134                                                 "Modifier: UA - Unnumbered acknowledgment" );
 135                                 else if ( modifier2 == 0 && modifier3 == 4 )
 136                                         proto_tree_add_text( tr, tvb, 1, 1,
 137                                                 "Modifier: SNRM - Set normal response mode" );
 138                                 else if ( modifier2 == 0 && modifier3 == 7 )
 139                                         proto_tree_add_text( tr, tvb, 1, 1,
 140                                                 "Modifier: TEST - Test" );
 141                                 else if ( modifier2 == 1 && modifier3 == 0 )
 142                                         proto_tree_add_text( tr, tvb, 1, 1,
 143                                                 "Modifier: SIM/RIM"
 144                                                 " - Set initialization mode/Request initialization mode" );
 145                                 else if ( modifier2 == 1 && modifier3 == 4 )
 146                                         proto_tree_add_text( tr, tvb, 1, 1,
 147                                                 "Modifier: FRMR - Frame reject" );
 148                                 else if ( modifier2 == 3 && modifier3 == 0 )
 149                                         proto_tree_add_text( tr, tvb, 1, 1,
 150                                                 "Modifier: SARM/DM"
 151                                                 " - Set asynchronous response mode/Disconnect mode" );
 152                                 else if ( modifier2 == 3 && modifier3 == 1 )
 153                                         proto_tree_add_text( tr, tvb, 1, 1,
 154                                                 "Modifier: SABM - Set asynchronous balanced mode" );
 155                                 else if ( modifier2 == 3 && modifier3 == 2 )
 156                                         proto_tree_add_text( tr, tvb, 1, 1,
 157                                                 "Modifier: SARME - Set asynchronous response extended mode" );
 158                                 else if ( modifier2 == 3 && modifier3 == 3 )
 159                                         proto_tree_add_text( tr, tvb, 1, 1,
 160                                                 "Modifier: SABME - Set asynchronous balanced extended mode" );
 161                                 else if ( modifier2 == 3 && modifier3 == 4 )
 162                                         proto_tree_add_text( tr, tvb, 1, 1,
 163                                                 "Modifier: RSET - Reset" );
 164                                 else if ( modifier2 == 3 && modifier3 == 5 )
 165                                         proto_tree_add_text( tr, tvb, 1, 1,
 166                                                 "Modifier: XID - Exchange identification" );
 167                                 else if ( modifier2 == 3 && modifier3 == 6 )
 168                                         proto_tree_add_text( tr, tvb, 1, 1,
 169                                                 "Modifier: SNRME - Set normal response extended mode" );
 170                         }
 171                         else
 172                         {
 173                                 proto_tree_add_text( tr, tvb, 1, 1, "S frame" );
 174                         }
 175                 }
 176                 else
 177                 {
 178                         proto_tree_add_text( tr, tvb, 1, 1, "I frame" );
 179                 }
 180         }
 181         call_dissector( ppp_handle, tvb_new_subset_remaining(tvb, 2), pinfo, tree );
 182 }
 183
 184 void proto_register_pw_hdlc(void)
 185 {
 186         static hf_register_info hf[] = {
 187                 {
 188                         &hf_pw_hdlc,
 189                         {
 190                                 "PW HDLC", "pw_hdlc", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL
 191                         }
 192                 },
 193                 {
 194                         &hf_pw_hdlc_address_field,
 195                         {
 196                                 "Address field", "pw_hdlc.address_field",
 197                                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL
 198                         }
 199                 },
 200                 {
 201                         &hf_pw_hdlc_address,
 202                         {
 203                                 "Address", "pw_hdlc.address",
 204                                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL
 205                         }
 206                 },
 207                 {
 208                         &hf_pw_hdlc_cr_bit,
 209                         {
 210                                 "C/R bit", "pw_hdlc.cr_bit",
 211                                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL
 212                         }
 213                 },
 214                 {
 215                         &hf_pw_hdlc_control_field,
 216                         {
 217                                 "Control field", "pw_hdlc.control_field",
 218                                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL
 219                         }
 220                 },
 221                 {
 222                         &hf_pw_hdlc_pf_bit,
 223                         {
 224                                 "Poll/Final bit", "pw_hdlc.pf_bit",
 225                                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL
 226                         }
 227                 }
 228         };
 229
 230         static gint *ett[] = {
 231                 &ett_pw_hdlc
 232         };
 233
 234         proto_pw_hdlc_nocw_fr = proto_register_protocol("HDLC PW, FR port mode (no CW)", /*not displayed*/
 235                                                         "HDLC PW, FR port mode (no CW)",
 236                                                         "pw_hdlc_nocw_fr" );
 237         proto_pw_hdlc_nocw_hdlc_ppp = proto_register_protocol("HDLC-like framing for PPP",
 238                                                               "HDLC PW with PPP payload (no CW)",
 239                                                               "pw_hdlc_nocw_hdlc_ppp" );
 240
 241         proto_register_field_array(proto_pw_hdlc_nocw_fr, hf, array_length(hf));
 242         proto_register_subtree_array(ett, array_length(ett));
 243
 244         register_dissector("pw_hdlc_nocw_fr", dissect_pw_hdlc_nocw_fr, proto_pw_hdlc_nocw_fr );
 245         register_dissector("pw_hdlc_nocw_hdlc_ppp", dissect_pw_hdlc_nocw_hdlc_ppp, proto_pw_hdlc_nocw_hdlc_ppp );
 246 }
 247
 248 void proto_reg_handoff_pw_hdlc(void)
 249 {
 250         dissector_handle_t handle;
 251
 252         handle = find_dissector("pw_hdlc_nocw_fr");
 253         dissector_add( "mpls.label", LABEL_INVALID, handle );
 254
 255         handle = find_dissector("pw_hdlc_nocw_hdlc_ppp");
 256         dissector_add( "mpls.label", LABEL_INVALID, handle );
 257
 258         ppp_handle = find_dissector( "ppp" );
 259         fr_handle = find_dissector( "fr" );
 260 }