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  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version 2
  12  * of the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  22  *
  23  * History:
  24  * ---------------------------------
  25  * 02.03.2009 Initial implementation, supports:
  26  * - HDLC mode (rfc4618 5.1), no CW, payload is PPP (PPP in HDLC-like Framing (rfc1662)).
  27  * - FR port mode (rfc4618 5.2), no CW.
  28  *
  29  * [informative: Not supported yet:
  30  * - All kinds of HDLC PW with CW.
  31  * - PPP mode (rfc4618 5.3).
  32  * - For HDLC mode, decoding payloads other than PPP.]
  33  */
  34
  35 #include "config.h"
  36
  37 #include <glib.h>
  38
  39 #include <epan/packet.h>
  40
  41 #include "packet-mpls.h"
  42
  43 void proto_register_pw_hdlc(void);
  44 void proto_reg_handoff_pw_hdlc(void);
  45
  46 static dissector_handle_t ppp_handle;
  47 static dissector_handle_t fr_handle;
  48
  49 static gint proto_pw_hdlc_nocw_fr = -1;
  50 static gint proto_pw_hdlc_nocw_hdlc_ppp = -1;
  51
  52 static gint ett_pw_hdlc = -1;
  53
  54 /* static int hf_pw_hdlc = -1; */
  55 static int hf_pw_hdlc_address_field = -1;
  56 static int hf_pw_hdlc_address = -1;
  57 static int hf_pw_hdlc_cr_bit = -1;
  58 static int hf_pw_hdlc_control_field = -1;
  59 static int hf_pw_hdlc_pf_bit = -1;
  60 static int hf_pw_hdlc_modifier = -1;
  61
  62 static const value_string pw_hdlc_modifier_vals[] = {
  63         {0x00, "UI - Unnumbered information" },
  64         {0x08, "UP - Unnumbered poll" },
  65         {0x10, "DISC/RD - Disconnect/Request disconnect" },
  66         {0x18, "UA - Unnumbered acknowledgment" },
  67         {0x20, "SNRM - Set normal response mode" },
  68         {0x38, "TEST - Test" },
  69         {0x01, "SIM/RIM - Set initialization mode/Request initialization mode" },
  70         {0x21, "FRMR - Frame reject" },
  71         {0x03, "SARM/DM - Set asynchronous response mode/Disconnect mode" },
  72         {0x0B, "SABM - Set asynchronous balanced mode" },
  73         {0x13, "SARME - Set asynchronous response extended mode" },
  74         {0x1B, "SABME - Set asynchronous balanced extended mode" },
  75         {0x23, "RSET - Reset" },
  76         {0x2B, "XID - Exchange identification" },
  77         {0x33, "SNRME - Set normal response extended mode" },
  78         {0, NULL }
  79 };
  80
  81 static void dissect_pw_hdlc_nocw_fr( tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree )
  82 {
  83         call_dissector( fr_handle, tvb, pinfo, tree );
  84 }
  85
  86
  87 static void dissect_pw_hdlc_nocw_hdlc_ppp( tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree )
  88 {
  89         if (tvb_reported_length_remaining(tvb, 0) < 2)
  90         {
  91                 proto_tree_add_text(tree, tvb, 0, -1, "Error processing message");
  92                 return;
  93         }
  94
  95         if (tree)
  96         {
  97                 proto_tree  *tr;
  98                 proto_item  *item;
  99                 proto_item  *item_address;
 100                 proto_item  *item_control;
 101                 guint8      addr;
 102                 guint8      control;
 103
 104                 addr    = tvb_get_guint8(tvb, 0);
 105                 control = tvb_get_guint8(tvb, 1);
 106
 107                 item = proto_tree_add_item( tree, proto_pw_hdlc_nocw_hdlc_ppp, tvb, 0, 2, ENC_NA );
 108
 109                 tr = proto_item_add_subtree( item, ett_pw_hdlc );
 110
 111                 item_address = proto_tree_add_item( tr, hf_pw_hdlc_address_field, tvb, 0, 1, ENC_NA );
 112                 item_control = proto_tree_add_item( tr, hf_pw_hdlc_control_field, tvb, 1, 1, ENC_NA );
 113
 114                 tr = proto_item_add_subtree( item_address, ett_pw_hdlc );
 115
 116                 if ( 0x3F == (( addr & 0xFC ) >> 2 ))
 117                         proto_tree_add_uint_format_value( tr, hf_pw_hdlc_address, tvb, 0, 1, 0xFC, "0x%x (All stations)", 0x3F );
 118                 else
 119                         proto_tree_add_uint( tr, hf_pw_hdlc_address, tvb, 0, 1, ( addr & 0xFC ) >> 2 );
 120
 121                 proto_tree_add_uint( tr, hf_pw_hdlc_cr_bit, tvb, 0, 1, ( addr & 2 ) >> 1 );
 122
 123                 tr = proto_item_add_subtree( item_control, ett_pw_hdlc );
 124
 125                 if ( control & 1 )
 126                 {
 127                         if ( control & 2 )
 128                         {
 129                                 proto_tree_add_text( tr, tvb, 1, 1, "U frame" );
 130
 131                                 proto_tree_add_uint( tr, hf_pw_hdlc_pf_bit, tvb, 1, 1, ( control & 0x10 ) >> 4 );
 132                                 proto_tree_add_uint( tr, hf_pw_hdlc_modifier, tvb, 1, 1, (control & 0xEC) >> 2);
 133                         }
 134                         else
 135                         {
 136                                 proto_tree_add_text( tr, tvb, 1, 1, "S frame" );
 137                         }
 138                 }
 139                 else
 140                 {
 141                         proto_tree_add_text( tr, tvb, 1, 1, "I frame" );
 142                 }
 143         }
 144         call_dissector( ppp_handle, tvb_new_subset_remaining(tvb, 2), pinfo, tree );
 145 }
 146
 147 void proto_register_pw_hdlc(void)
 148 {
 149         static hf_register_info hf[] = {
 150 #if 0
 151                 {
 152                         &hf_pw_hdlc,
 153                         {
 154                                 "PW HDLC", "pw_hdlc", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL
 155                         }
 156                 },
 157 #endif
 158                 {
 159                         &hf_pw_hdlc_address_field,
 160                         {
 161                                 "Address field", "pw_hdlc.address_field",
 162                                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL
 163                         }
 164                 },
 165                 {
 166                         &hf_pw_hdlc_address,
 167                         {
 168                                 "Address", "pw_hdlc.address",
 169                                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL
 170                         }
 171                 },
 172                 {
 173                         &hf_pw_hdlc_cr_bit,
 174                         {
 175                                 "C/R bit", "pw_hdlc.cr_bit",
 176                                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL
 177                         }
 178                 },
 179                 {
 180                         &hf_pw_hdlc_control_field,
 181                         {
 182                                 "Control field", "pw_hdlc.control_field",
 183                                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL
 184                         }
 185                 },
 186                 {
 187                         &hf_pw_hdlc_pf_bit,
 188                         {
 189                                 "Poll/Final bit", "pw_hdlc.pf_bit",
 190                                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL
 191                         }
 192                 },
 193                 {
 194                         &hf_pw_hdlc_modifier,
 195                         {
 196                                 "Modifier", "pw_hdlc.modifier",
 197                                 FT_UINT8, BASE_HEX, VALS(pw_hdlc_modifier_vals), 0x0, NULL, HFILL
 198                         }
 199                 }
 200         };
 201
 202         static gint *ett[] = {
 203                 &ett_pw_hdlc
 204         };
 205
 206         proto_pw_hdlc_nocw_fr = proto_register_protocol("HDLC PW, FR port mode (no CW)", /*not displayed*/
 207                                                         "HDLC PW, FR port mode (no CW)",
 208                                                         "pw_hdlc_nocw_fr" );
 209         proto_pw_hdlc_nocw_hdlc_ppp = proto_register_protocol("HDLC-like framing for PPP",
 210                                                               "HDLC PW with PPP payload (no CW)",
 211                                                               "pw_hdlc_nocw_hdlc_ppp" );
 212
 213         proto_register_field_array(proto_pw_hdlc_nocw_fr, hf, array_length(hf));
 214         proto_register_subtree_array(ett, array_length(ett));
 215
 216         register_dissector("pw_hdlc_nocw_fr", dissect_pw_hdlc_nocw_fr, proto_pw_hdlc_nocw_fr );
 217         register_dissector("pw_hdlc_nocw_hdlc_ppp", dissect_pw_hdlc_nocw_hdlc_ppp, proto_pw_hdlc_nocw_hdlc_ppp );
 218 }
 219
 220 void proto_reg_handoff_pw_hdlc(void)
 221 {
 222         dissector_handle_t handle;
 223
 224         handle = find_dissector("pw_hdlc_nocw_fr");
 225         dissector_add_uint( "mpls.label", MPLS_LABEL_INVALID, handle );
 226
 227         handle = find_dissector("pw_hdlc_nocw_hdlc_ppp");
 228         dissector_add_uint( "mpls.label", MPLS_LABEL_INVALID, handle );
 229
 230         ppp_handle = find_dissector( "ppp" );
 231         fr_handle = find_dissector( "fr" );
 232 }