epan/dissectors/packet-gsm_ipa.c

   1 /* packet-gsm_ipa.c
   2  * Routines for packet dissection of ip.access GSM over IP
   3  * Copyright 2009 by Harald Welte <laforge@gnumonks.org>
   4  * Copyright 2009, 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
   5  *
   6  * $Id$
   7  *
   8  * Wireshark - Network traffic analyzer
   9  * By Gerald Combs <gerald@wireshark.org>
  10  * Copyright 1998 Gerald Combs
  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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <glib.h>
  32
  33 #include <epan/packet.h>
  34 #include <epan/ipproto.h>
  35 #include <epan/prefs.h>
  36
  37 #define IPA_TCP_PORTS "3002,3003,3006,5000"
  38 #define IPA_UDP_PORTS "3006"
  39
  40 static dissector_handle_t ipa_handle;
  41 static range_t *global_ipa_tcp_ports = NULL;
  42 static range_t *global_ipa_udp_ports = NULL;
  43 static gboolean global_ipa_in_root = FALSE;
  44 static gboolean global_ipa_in_info = FALSE;
  45
  46 /* Initialize the protocol and registered fields */
  47 static int proto_ipa = -1;
  48 static int proto_ipaccess = -1;
  49
  50 static int hf_ipa_data_len = -1;
  51 static int hf_ipa_protocol = -1;
  52 static int hf_ipa_hsl_debug = -1;
  53
  54 static int hf_ipaccess_msgtype = -1;
  55 static int hf_ipaccess_attr_tag = -1;
  56 static int hf_ipaccess_attr_string = -1;
  57
  58 /* Initialize the subtree pointers */
  59 static gint ett_ipa = -1;
  60 static gint ett_ipaccess = -1;
  61
  62 enum {
  63         SUB_OML,
  64         SUB_RSL,
  65         SUB_SCCP,
  66         SUB_MGCP,
  67 /*      SUB_IPACCESS, */
  68
  69         SUB_MAX
  70 };
  71
  72 static dissector_handle_t sub_handles[SUB_MAX];
  73
  74 #define ABISIP_RSL_MAX  0x20
  75 #define HSL_DEBUG       0xdd
  76 #define IPA_MGCP        0xfc
  77 #define AIP_SCCP        0xfd
  78 #define ABISIP_IPACCESS 0xfe
  79 #define ABISIP_OML      0xff
  80
  81 static const value_string ipa_protocol_vals[] = {
  82         { 0x00,         "RSL" },
  83         { 0xdd,         "HSL Debug" },
  84         { 0xfc,         "MGCP" },
  85         { 0xfd,         "SCCP" },
  86         { 0xfe,         "IPA" },
  87         { 0xff,         "OML" },
  88         { 0,            NULL }
  89 };
  90
  91 static const value_string ipaccess_msgtype_vals[] = {
  92         { 0x00,         "PING?" },
  93         { 0x01,         "PONG!" },
  94         { 0x04,         "IDENTITY REQUEST" },
  95         { 0x05,         "IDENTITY RESPONSE" },
  96         { 0x06,         "IDENTITY ACK" },
  97         { 0x07,         "IDENTITY NACK" },
  98         { 0x08,         "PROXY REQUEST" },
  99         { 0x09,         "PROXY ACK" },
 100         { 0x0a,         "PROXY NACK" },
 101         { 0,            NULL }
 102 };
 103
 104 static const value_string ipaccess_idtag_vals[] = {
 105         { 0x00,         "Serial Number" },
 106         { 0x01,         "Unit Name" },
 107         { 0x02,         "Location" },
 108         { 0x03,         "Unit Type" },
 109         { 0x04,         "Equipment Version" },
 110         { 0x05,         "Software Version" },
 111         { 0x06,         "IP Address" },
 112         { 0x07,         "MAC Address" },
 113         { 0x08,         "Unit ID" },
 114         { 0,            NULL }
 115 };
 116
 117 static gint
 118 dissect_ipa_attr(tvbuff_t *tvb, int base_offs, proto_tree *tree)
 119 {
 120         guint8 len, attr_type;
 121
 122         int offset = base_offs;
 123
 124         while (tvb_reported_length_remaining(tvb, offset) > 0) {
 125                 attr_type = tvb_get_guint8(tvb, offset);
 126
 127                 switch (attr_type) {
 128                 case 0x00:      /* a string prefixed by its length */
 129                         len = tvb_get_guint8(tvb, offset+1);
 130                         proto_tree_add_item(tree, hf_ipaccess_attr_tag,
 131                                             tvb, offset+2, 1, FALSE);
 132                         proto_tree_add_item(tree, hf_ipaccess_attr_string,
 133                                             tvb, offset+3, len-1, FALSE);
 134                         break;
 135                 case 0x01:      /* a single-byte reqest for a certain attr */
 136                         len = 0;
 137                         proto_tree_add_item(tree, hf_ipaccess_attr_tag,
 138                                             tvb, offset+1, 1, FALSE);
 139                         break;
 140                 default:
 141                         len = 0;
 142                         proto_tree_add_text(tree, tvb, offset+1, 1,
 143                                             "unknown attribute type 0x%02x",
 144                                             attr_type);
 145                         break;
 146                 };
 147                 offset += len + 2;
 148         };
 149         return offset;
 150 }
 151
 152 /* Dissect an ip.access specific message */
 153 static gint
 154 dissect_ipaccess(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 155 {
 156         proto_item *ti;
 157         proto_tree *ipaccess_tree;
 158         guint8 msg_type;
 159
 160         msg_type = tvb_get_guint8(tvb, 0);
 161
 162         col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
 163                         val_to_str(msg_type, ipaccess_msgtype_vals,
 164                                    "unknown 0x%02x"));
 165         if (tree) {
 166                 ti = proto_tree_add_item(tree, proto_ipaccess, tvb, 0, -1, FALSE);
 167                 ipaccess_tree = proto_item_add_subtree(ti, ett_ipaccess);
 168                 proto_tree_add_item(ipaccess_tree, hf_ipaccess_msgtype,
 169                                     tvb, 0, 1, FALSE);
 170                 switch (msg_type) {
 171                 case 4:
 172                 case 5:
 173                         dissect_ipa_attr(tvb, 1, ipaccess_tree);
 174                         break;
 175                 }
 176         }
 177
 178         return 1;
 179 }
 180
 181
 182 /* Code to actually dissect the packets */
 183 static void
 184 dissect_ipa(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 185 {
 186         gint remaining;
 187         gint header_length = 3;
 188         int offset = 0;
 189
 190         col_set_str(pinfo->cinfo, COL_PROTOCOL, "IPA");
 191         col_clear(pinfo->cinfo, COL_INFO);
 192
 193         while ((remaining = tvb_reported_length_remaining(tvb, offset)) > 0) {
 194                 proto_item *ti;
 195                 proto_tree *ipa_tree = NULL;
 196                 guint16 len, msg_type;
 197                 tvbuff_t *next_tvb;
 198
 199                 len = tvb_get_ntohs(tvb, offset);
 200                 msg_type = tvb_get_guint8(tvb, offset+2);
 201
 202                 col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
 203                                 val_to_str(msg_type, ipa_protocol_vals,
 204                                            "unknown 0x%02x"));
 205
 206                 /*
 207                  * The IPA header is different depending on the transport protocol.
 208                  * With UDP there seems to be a fourth byte for the IPA header.
 209                  * We attempt to detect this by checking if the length from the
 210                  * header + four bytes of the IPA header equals the remaining size.
 211                  */
 212                 if ((pinfo->ipproto == IP_PROTO_UDP) && (len + 4 == remaining)) {
 213                         header_length++;
 214                 }
 215
 216                 if (tree) {
 217                         ti = proto_tree_add_protocol_format(tree, proto_ipa,
 218                                         tvb, offset, len+header_length,
 219                                         "IPA protocol ip.access, type: %s",
 220                                         val_to_str(msg_type, ipa_protocol_vals,
 221                                                    "unknown 0x%02x"));
 222                         ipa_tree = proto_item_add_subtree(ti, ett_ipa);
 223                         proto_tree_add_item(ipa_tree, hf_ipa_data_len,
 224                                             tvb, offset, 2, FALSE);
 225                         proto_tree_add_item(ipa_tree, hf_ipa_protocol,
 226                                             tvb, offset+2, 1, FALSE);
 227                 }
 228
 229                 next_tvb = tvb_new_subset(tvb, offset+header_length, len, len);
 230
 231                 switch (msg_type) {
 232                 case ABISIP_OML:
 233                         /* hand this off to the standard A-bis OML dissector */
 234                         if (sub_handles[SUB_OML])
 235                                 call_dissector(sub_handles[SUB_OML], next_tvb,
 236                                                  pinfo, tree);
 237                         break;
 238                 case ABISIP_IPACCESS:
 239                         dissect_ipaccess(next_tvb, pinfo, tree);
 240                         break;
 241                 case AIP_SCCP:
 242                         /* hand this off to the standard SCCP dissector */
 243                         call_dissector(sub_handles[SUB_SCCP], next_tvb, pinfo, tree);
 244                         break;
 245                 case IPA_MGCP:
 246                         /* hand this off to the standard MGCP dissector */
 247                         call_dissector(sub_handles[SUB_MGCP], next_tvb, pinfo, tree);
 248                         break;
 249                 case HSL_DEBUG:
 250                         if (tree) {
 251                                 proto_tree_add_item(ipa_tree, hf_ipa_hsl_debug,
 252                                                     next_tvb, 0, len, FALSE);
 253                                 if (global_ipa_in_root == TRUE)
 254                                         proto_tree_add_item(tree, hf_ipa_hsl_debug,
 255                                                             next_tvb, 0, len, FALSE);
 256                         }
 257                         if (global_ipa_in_info == TRUE)
 258                                 col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
 259                                                 tvb_get_stringz(next_tvb, 0, NULL));
 260                         break;
 261                 default:
 262                         if (msg_type < ABISIP_RSL_MAX) {
 263                                 /* hand this off to the standard A-bis RSL dissector */
 264                                 call_dissector(sub_handles[SUB_RSL], next_tvb, pinfo, tree);
 265                         }
 266                         break;
 267                 }
 268                 offset += len + header_length;
 269         }
 270 }
 271
 272 void proto_reg_handoff_gsm_ipa(void);
 273
 274 void proto_register_ipa(void)
 275 {
 276         module_t *ipa_module;
 277
 278         static hf_register_info hf[] = {
 279                 {&hf_ipa_data_len,
 280                  {"DataLen", "ipa.data_len",
 281                   FT_UINT16, BASE_DEC, NULL, 0x0,
 282                   "The length of the data (in bytes)", HFILL}
 283                  },
 284                 {&hf_ipa_protocol,
 285                  {"Protocol", "ipa.protocol",
 286                   FT_UINT8, BASE_HEX, VALS(ipa_protocol_vals), 0x0,
 287                   "The IPA Sub-Protocol", HFILL}
 288                  },
 289                 {&hf_ipa_hsl_debug,
 290                  {"Debug Message", "ipa.hsl_debug",
 291                   FT_STRING, BASE_NONE, NULL, 0,
 292                   "Hay Systems Limited debug message", HFILL}
 293                 },
 294         };
 295         static hf_register_info hf_ipa[] = {
 296                 {&hf_ipaccess_msgtype,
 297                  {"MessageType", "ipaccess.msg_type",
 298                   FT_UINT8, BASE_HEX, VALS(ipaccess_msgtype_vals), 0x0,
 299                   "Type of ip.access messsage", HFILL}
 300                  },
 301                 {&hf_ipaccess_attr_tag,
 302                  {"Tag", "ipaccess.attr_tag",
 303                   FT_UINT8, BASE_HEX, VALS(ipaccess_idtag_vals), 0x0,
 304                   "Attribute Tag", HFILL}
 305                  },
 306                 {&hf_ipaccess_attr_string,
 307                  {"String", "ipaccess.attr_string",
 308                   FT_STRING, BASE_NONE, NULL, 0x0,
 309                   "String attribute", HFILL}
 310                  },
 311         };
 312
 313         static gint *ett[] = {
 314                 &ett_ipa,
 315                 &ett_ipaccess,
 316         };
 317
 318         proto_ipa =
 319             proto_register_protocol("GSM over IP protocol as used by ip.access",
 320                                     "GSM over IP", "gsm_ipa");
 321         proto_ipaccess =
 322             proto_register_protocol("GSM over IP ip.access CCM sub-protocol",
 323                                     "IPA", "ipaccess");
 324
 325         proto_register_field_array(proto_ipa, hf, array_length(hf));
 326         proto_register_field_array(proto_ipaccess, hf_ipa, array_length(hf_ipa));
 327         proto_register_subtree_array(ett, array_length(ett));
 328
 329         register_dissector("gsm_ipa", dissect_ipa, proto_ipa);
 330
 331         range_convert_str(&global_ipa_tcp_ports, IPA_TCP_PORTS, MAX_TCP_PORT);
 332         range_convert_str(&global_ipa_udp_ports, IPA_UDP_PORTS, MAX_UDP_PORT);
 333         ipa_module = prefs_register_protocol(proto_ipa,
 334                                              proto_reg_handoff_gsm_ipa);
 335
 336         prefs_register_range_preference(ipa_module, "tcp_ports",
 337                                         "GSM IPA TCP Port(s)",
 338                                         "Set the port(s) for ip.access IPA"
 339                                         " (default: " IPA_TCP_PORTS ")",
 340                                         &global_ipa_tcp_ports, MAX_TCP_PORT);
 341         prefs_register_range_preference(ipa_module, "udp_ports",
 342                                         "GSM IPA UDP Port(s)",
 343                                         "Set the port(s) for ip.access IPA"
 344                                         " (default: " IPA_UDP_PORTS ")",
 345                                         &global_ipa_udp_ports, MAX_UDP_PORT);
 346
 347         prefs_register_bool_preference(ipa_module, "hsl_debug_in_root_tree",
 348                                         "HSL Debug messages in root protocol tree",
 349                                         NULL, &global_ipa_in_root);
 350         prefs_register_bool_preference(ipa_module, "hsl_debug_in_info",
 351                                         "HSL Debug messages in INFO column",
 352                                         NULL, &global_ipa_in_info);
 353 }
 354
 355 static void ipa_tcp_delete_callback(guint32 port)
 356 {
 357         if (port)
 358                 dissector_delete_uint("tcp.port", port, ipa_handle);
 359 }
 360
 361 static void ipa_udp_delete_callback(guint32 port)
 362 {
 363         if (port)
 364                 dissector_delete_uint("udp.port", port, ipa_handle);
 365 }
 366
 367 static void ipa_tcp_add_callback(guint32 port)
 368 {
 369         if (port)
 370                 dissector_add_uint("tcp.port", port, ipa_handle);
 371 }
 372
 373 static void ipa_udp_add_callback(guint32 port)
 374 {
 375         if (port)
 376                 dissector_add_uint("udp.port", port, ipa_handle);
 377 }
 378
 379 void proto_reg_handoff_gsm_ipa(void)
 380 {
 381         static gboolean ipa_initialized = FALSE;
 382         static range_t *ipa_tcp_ports, *ipa_udp_ports;
 383
 384         if (!ipa_initialized) {
 385                 sub_handles[SUB_RSL] = find_dissector("gsm_abis_rsl");
 386                 sub_handles[SUB_OML] = find_dissector("gsm_abis_oml");
 387                 sub_handles[SUB_SCCP] = find_dissector("sccp");
 388                 sub_handles[SUB_MGCP] = find_dissector("mgcp");
 389
 390                 ipa_handle = create_dissector_handle(dissect_ipa, proto_ipa);
 391                 ipa_initialized = TRUE;
 392         } else {
 393                 range_foreach(ipa_tcp_ports, ipa_tcp_delete_callback);
 394                 g_free(ipa_tcp_ports);
 395                 range_foreach(ipa_udp_ports, ipa_udp_delete_callback);
 396                 g_free(ipa_udp_ports);
 397         }
 398
 399         ipa_tcp_ports = range_copy(global_ipa_tcp_ports);
 400         ipa_udp_ports = range_copy(global_ipa_udp_ports);
 401
 402         range_foreach(ipa_tcp_ports, ipa_tcp_add_callback);
 403         range_foreach(ipa_udp_ports, ipa_udp_add_callback);
 404 }