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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 #include "config.h"
  38
  39 #include <glib.h>
  40
  41 #include <epan/packet.h>
  42
  43 #include "packet-mpls.h"
  44
  45 static dissector_handle_t ppp_handle;
  46 static dissector_handle_t fr_handle;
  47
  48 static gint proto_pw_hdlc_nocw_fr = -1;
  49 static gint proto_pw_hdlc_nocw_hdlc_ppp = -1;
  50
  51 static gint ett_pw_hdlc = -1;
  52
  53 /* static int hf_pw_hdlc = -1; */
  54 static int hf_pw_hdlc_address_field = -1;
  55 static int hf_pw_hdlc_address = -1;
  56 static int hf_pw_hdlc_cr_bit = -1;
  57 static int hf_pw_hdlc_control_field = -1;
  58 static int hf_pw_hdlc_pf_bit = -1;
  59 static int hf_pw_hdlc_modifier = -1;
  60
  61 static const value_string pw_hdlc_modifier_vals[] = {
  62         {0x00, "UI - Unnumbered information" },
  63         {0x08, "UP - Unnumbered poll" },
  64         {0x10, "DISC/RD - Disconnect/Request disconnect" },
  65         {0x18, "UA - Unnumbered acknowledgment" },
  66         {0x20, "SNRM - Set normal response mode" },
  67         {0x38, "TEST - Test" },
  68         {0x01, "SIM/RIM - Set initialization mode/Request initialization mode" },
  69         {0x21, "FRMR - Frame reject" },
  70         {0x03, "SARM/DM - Set asynchronous response mode/Disconnect mode" },
  71         {0x0B, "SABM - Set asynchronous balanced mode" },
  72         {0x13, "SARME - Set asynchronous response extended mode" },
  73         {0x1B, "SABME - Set asynchronous balanced extended mode" },
  74         {0x23, "RSET - Reset" },
  75         {0x2B, "XID - Exchange identification" },
  76         {0x33, "SNRME - Set normal response extended mode" },
  77         {0, NULL }
  78 };
  79
  80 static void dissect_pw_hdlc_nocw_fr( tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree )
  81 {
  82         call_dissector( fr_handle, tvb, pinfo, tree );
  83 }
  84
  85
  86 static void dissect_pw_hdlc_nocw_hdlc_ppp( tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree )
  87 {
  88         if (tvb_reported_length_remaining(tvb, 0) < 2)
  89         {
  90                 proto_tree_add_text(tree, tvb, 0, -1, "Error processing message");
  91                 return;
  92         }
  93
  94         if (tree)
  95         {
  96                 proto_tree  *tr;
  97                 proto_item  *item;
  98                 proto_item  *item_address;
  99                 proto_item  *item_control;
 100                 guint8      addr;
 101                 guint8      control;
 102
 103                 addr    = tvb_get_guint8(tvb, 0);
 104                 control = tvb_get_guint8(tvb, 1);
 105
 106                 item = proto_tree_add_item( tree, proto_pw_hdlc_nocw_hdlc_ppp, tvb, 0, 2, ENC_NA );
 107
 108                 tr = proto_item_add_subtree( item, ett_pw_hdlc );
 109
 110                 item_address = proto_tree_add_item( tr, hf_pw_hdlc_address_field, tvb, 0, 1, ENC_NA );
 111                 item_control = proto_tree_add_item( tr, hf_pw_hdlc_control_field, tvb, 1, 1, ENC_NA );
 112
 113                 tr = proto_item_add_subtree( item_address, ett_pw_hdlc );
 114
 115                 if ( 0x3F == (( addr & 0xFC ) >> 2 ))
 116                         proto_tree_add_uint_format_value( tr, hf_pw_hdlc_address, tvb, 0, 1, 0xFC, "0x%x (All stations)", 0x3F );
 117                 else
 118                         proto_tree_add_uint( tr, hf_pw_hdlc_address, tvb, 0, 1, ( addr & 0xFC ) >> 2 );
 119
 120                 proto_tree_add_uint( tr, hf_pw_hdlc_cr_bit, tvb, 0, 1, ( addr & 2 ) >> 1 );
 121
 122                 tr = proto_item_add_subtree( item_control, ett_pw_hdlc );
 123
 124                 if ( control & 1 )
 125                 {
 126                         if ( control & 2 )
 127                         {
 128                                 proto_tree_add_text( tr, tvb, 1, 1, "U frame" );
 129
 130                                 proto_tree_add_uint( tr, hf_pw_hdlc_pf_bit, tvb, 1, 1, ( control & 0x10 ) >> 4 );
 131                                 proto_tree_add_uint( tr, hf_pw_hdlc_modifier, tvb, 1, 1, (control & 0xEC) >> 2);
 132                         }
 133                         else
 134                         {
 135                                 proto_tree_add_text( tr, tvb, 1, 1, "S frame" );
 136                         }
 137                 }
 138                 else
 139                 {
 140                         proto_tree_add_text( tr, tvb, 1, 1, "I frame" );
 141                 }
 142         }
 143         call_dissector( ppp_handle, tvb_new_subset_remaining(tvb, 2), pinfo, tree );
 144 }
 145
 146 void proto_register_pw_hdlc(void)
 147 {
 148         static hf_register_info hf[] = {
 149 #if 0
 150                 {
 151                         &hf_pw_hdlc,
 152                         {
 153                                 "PW HDLC", "pw_hdlc", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL
 154                         }
 155                 },
 156 #endif
 157                 {
 158                         &hf_pw_hdlc_address_field,
 159                         {
 160                                 "Address field", "pw_hdlc.address_field",
 161                                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL
 162                         }
 163                 },
 164                 {
 165                         &hf_pw_hdlc_address,
 166                         {
 167                                 "Address", "pw_hdlc.address",
 168                                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL
 169                         }
 170                 },
 171                 {
 172                         &hf_pw_hdlc_cr_bit,
 173                         {
 174                                 "C/R bit", "pw_hdlc.cr_bit",
 175                                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL
 176                         }
 177                 },
 178                 {
 179                         &hf_pw_hdlc_control_field,
 180                         {
 181                                 "Control field", "pw_hdlc.control_field",
 182                                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL
 183                         }
 184                 },
 185                 {
 186                         &hf_pw_hdlc_pf_bit,
 187                         {
 188                                 "Poll/Final bit", "pw_hdlc.pf_bit",
 189                                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL
 190                         }
 191                 },
 192                 {
 193                         &hf_pw_hdlc_modifier,
 194                         {
 195                                 "Modifier", "pw_hdlc.modifier",
 196                                 FT_UINT8, BASE_HEX, VALS(pw_hdlc_modifier_vals), 0x0, NULL, HFILL
 197                         }
 198                 }
 199         };
 200
 201         static gint *ett[] = {
 202                 &ett_pw_hdlc
 203         };
 204
 205         proto_pw_hdlc_nocw_fr = proto_register_protocol("HDLC PW, FR port mode (no CW)", /*not displayed*/
 206                                                         "HDLC PW, FR port mode (no CW)",
 207                                                         "pw_hdlc_nocw_fr" );
 208         proto_pw_hdlc_nocw_hdlc_ppp = proto_register_protocol("HDLC-like framing for PPP",
 209                                                               "HDLC PW with PPP payload (no CW)",
 210                                                               "pw_hdlc_nocw_hdlc_ppp" );
 211
 212         proto_register_field_array(proto_pw_hdlc_nocw_fr, hf, array_length(hf));
 213         proto_register_subtree_array(ett, array_length(ett));
 214
 215         register_dissector("pw_hdlc_nocw_fr", dissect_pw_hdlc_nocw_fr, proto_pw_hdlc_nocw_fr );
 216         register_dissector("pw_hdlc_nocw_hdlc_ppp", dissect_pw_hdlc_nocw_hdlc_ppp, proto_pw_hdlc_nocw_hdlc_ppp );
 217 }
 218
 219 void proto_reg_handoff_pw_hdlc(void)
 220 {
 221         dissector_handle_t handle;
 222
 223         handle = find_dissector("pw_hdlc_nocw_fr");
 224         dissector_add_uint( "mpls.label", MPLS_LABEL_INVALID, handle );
 225
 226         handle = find_dissector("pw_hdlc_nocw_hdlc_ppp");
 227         dissector_add_uint( "mpls.label", MPLS_LABEL_INVALID, handle );
 228
 229         ppp_handle = find_dissector( "ppp" );
 230         fr_handle = find_dissector( "fr" );
 231 }