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 /* http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml
  38  *
  39  * exlm-agent     3002
  40  * cgms           3003
  41  * ii-admin       3006
  42  * vrml-multi-use 4200-4299
  43  * commplex-main  5000
  44  */
  45 #define IPA_TCP_PORTS "3002,3003,3006,4249,4250,5000"
  46 #define IPA_UDP_PORTS "3006"
  47
  48 static dissector_handle_t ipa_handle;
  49 static range_t *global_ipa_tcp_ports = NULL;
  50 static range_t *global_ipa_udp_ports = NULL;
  51 static gboolean global_ipa_in_root = FALSE;
  52 static gboolean global_ipa_in_info = FALSE;
  53
  54 /* Initialize the protocol and registered fields */
  55 static int proto_ipa = -1;
  56 static int proto_ipaccess = -1;
  57
  58 static int hf_ipa_data_len = -1;
  59 static int hf_ipa_protocol = -1;
  60 static int hf_ipa_hsl_debug = -1;
  61 static int hf_ipa_osmo_proto = -1;
  62 static int hf_ipa_osmo_ctrl_data = -1;
  63
  64 static int hf_ipaccess_msgtype = -1;
  65 static int hf_ipaccess_attr_tag = -1;
  66 static int hf_ipaccess_attr_string = -1;
  67
  68 /* Initialize the subtree pointers */
  69 static gint ett_ipa = -1;
  70 static gint ett_ipaccess = -1;
  71
  72 enum {
  73         SUB_OML,
  74         SUB_RSL,
  75         SUB_SCCP,
  76         SUB_MGCP,
  77 /*      SUB_IPACCESS, */
  78         SUB_DATA,
  79
  80         SUB_MAX
  81 };
  82
  83 static dissector_handle_t sub_handles[SUB_MAX];
  84 static dissector_table_t osmo_dissector_table;
  85
  86
  87 #define ABISIP_RSL_MAX  0x20
  88 #define HSL_DEBUG       0xdd
  89 #define OSMO_EXT        0xee
  90 #define IPA_MGCP        0xfc
  91 #define AIP_SCCP        0xfd
  92 #define ABISIP_IPACCESS 0xfe
  93 #define ABISIP_OML      0xff
  94 #define IPAC_PROTO_EXT_CTRL     0x00
  95 #define IPAC_PROTO_EXT_MGCP     0x01
  96
  97 static const value_string ipa_protocol_vals[] = {
  98         { 0x00,         "RSL" },
  99         { 0xdd,         "HSL Debug" },
 100         { 0xee,         "OSMO EXT" },
 101         { 0xfc,         "MGCP (old)" },
 102         { 0xfd,         "SCCP" },
 103         { 0xfe,         "IPA" },
 104         { 0xff,         "OML" },
 105         { 0,            NULL }
 106 };
 107
 108 static const value_string ipaccess_msgtype_vals[] = {
 109         { 0x00,         "PING?" },
 110         { 0x01,         "PONG!" },
 111         { 0x04,         "IDENTITY REQUEST" },
 112         { 0x05,         "IDENTITY RESPONSE" },
 113         { 0x06,         "IDENTITY ACK" },
 114         { 0x07,         "IDENTITY NACK" },
 115         { 0x08,         "PROXY REQUEST" },
 116         { 0x09,         "PROXY ACK" },
 117         { 0x0a,         "PROXY NACK" },
 118         { 0,            NULL }
 119 };
 120
 121 static const value_string ipaccess_idtag_vals[] = {
 122         { 0x00,         "Serial Number" },
 123         { 0x01,         "Unit Name" },
 124         { 0x02,         "Location" },
 125         { 0x03,         "Unit Type" },
 126         { 0x04,         "Equipment Version" },
 127         { 0x05,         "Software Version" },
 128         { 0x06,         "IP Address" },
 129         { 0x07,         "MAC Address" },
 130         { 0x08,         "Unit ID" },
 131         { 0,            NULL }
 132 };
 133
 134 static const value_string ipa_osmo_proto_vals[] = {
 135         { 0x00,         "CTRL" },
 136         { 0x01,         "MGCP" },
 137         { 0x02,         "LAC" },
 138         { 0x03,         "SMSC" },
 139         { 0,            NULL }
 140 };
 141
 142
 143 static gint
 144 dissect_ipa_attr(tvbuff_t *tvb, int base_offs, proto_tree *tree)
 145 {
 146         guint8 len, attr_type;
 147
 148         int offset = base_offs;
 149
 150         while (tvb_reported_length_remaining(tvb, offset) > 0) {
 151                 attr_type = tvb_get_guint8(tvb, offset);
 152
 153                 switch (attr_type) {
 154                 case 0x00:      /* a string prefixed by its length */
 155                         len = tvb_get_guint8(tvb, offset+1);
 156                         proto_tree_add_item(tree, hf_ipaccess_attr_tag,
 157                                             tvb, offset+2, 1, ENC_BIG_ENDIAN);
 158                         proto_tree_add_item(tree, hf_ipaccess_attr_string,
 159                                             tvb, offset+3, len-1, ENC_ASCII|ENC_NA);
 160                         break;
 161                 case 0x01:      /* a single-byte reqest for a certain attr */
 162                         len = 0;
 163                         proto_tree_add_item(tree, hf_ipaccess_attr_tag,
 164                                             tvb, offset+1, 1, ENC_BIG_ENDIAN);
 165                         break;
 166                 default:
 167                         len = 0;
 168                         proto_tree_add_text(tree, tvb, offset+1, 1,
 169                                             "unknown attribute type 0x%02x",
 170                                             attr_type);
 171                         break;
 172                 };
 173                 offset += len + 2;
 174         };
 175         return offset;
 176 }
 177
 178 /* Dissect an ip.access specific message */
 179 static gint
 180 dissect_ipaccess(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 181 {
 182         proto_item *ti;
 183         proto_tree *ipaccess_tree;
 184         guint8 msg_type;
 185
 186         msg_type = tvb_get_guint8(tvb, 0);
 187
 188         col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
 189                         val_to_str(msg_type, ipaccess_msgtype_vals,
 190                                    "unknown 0x%02x"));
 191         if (tree) {
 192                 ti = proto_tree_add_item(tree, proto_ipaccess, tvb, 0, -1, ENC_BIG_ENDIAN);
 193                 ipaccess_tree = proto_item_add_subtree(ti, ett_ipaccess);
 194                 proto_tree_add_item(ipaccess_tree, hf_ipaccess_msgtype,
 195                                     tvb, 0, 1, ENC_BIG_ENDIAN);
 196                 switch (msg_type) {
 197                 case 4:
 198                 case 5:
 199                         dissect_ipa_attr(tvb, 1, ipaccess_tree);
 200                         break;
 201                 }
 202         }
 203
 204         return 1;
 205 }
 206
 207 /* Dissect the osmocom extension header */
 208 static gint
 209 dissect_osmo(tvbuff_t *tvb, packet_info *pinfo, proto_tree *ipatree, proto_tree *tree)
 210 {
 211         tvbuff_t *next_tvb;
 212         guint8 osmo_proto;
 213
 214         osmo_proto = tvb_get_guint8(tvb, 0);
 215
 216         col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
 217                         val_to_str(osmo_proto, ipa_osmo_proto_vals,
 218                                    "unknown 0x%02x"));
 219         if (ipatree) {
 220                 proto_tree_add_item(ipatree, hf_ipa_osmo_proto,
 221                                     tvb, 0, 1, ENC_BIG_ENDIAN);
 222         }
 223
 224         next_tvb = tvb_new_subset_remaining(tvb, 1);
 225
 226         /* Call any subdissectors that registered for this protocol */
 227         if (dissector_try_uint(osmo_dissector_table, osmo_proto, next_tvb, pinfo, tree))
 228                 return 1;
 229
 230         /* Fallback to the standard MGCP dissector */
 231         if (osmo_proto == IPAC_PROTO_EXT_MGCP) {
 232                 call_dissector(sub_handles[SUB_MGCP], next_tvb, pinfo, tree);
 233                 return 1;
 234         /* Simply display the CTRL data as text */
 235         } else if (osmo_proto == IPAC_PROTO_EXT_CTRL) {
 236                 if (tree) {
 237                         proto_tree_add_item(tree, hf_ipa_osmo_ctrl_data, next_tvb, 0, -1, ENC_ASCII|ENC_NA);
 238                 }
 239                 return 1;
 240         }
 241
 242         call_dissector(sub_handles[SUB_DATA], next_tvb, pinfo, tree);
 243
 244         return 1;
 245 }
 246
 247
 248
 249 /* Code to actually dissect the packets */
 250 static void
 251 dissect_ipa(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 252 {
 253         gint remaining;
 254         gint header_length = 3;
 255         int offset = 0;
 256
 257         col_set_str(pinfo->cinfo, COL_PROTOCOL, "IPA");
 258         col_clear(pinfo->cinfo, COL_INFO);
 259
 260         while ((remaining = tvb_reported_length_remaining(tvb, offset)) > 0) {
 261                 proto_item *ti;
 262                 proto_tree *ipa_tree = NULL;
 263                 guint16 len, msg_type;
 264                 tvbuff_t *next_tvb;
 265
 266                 len = tvb_get_ntohs(tvb, offset);
 267                 msg_type = tvb_get_guint8(tvb, offset+2);
 268
 269                 col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
 270                                 val_to_str(msg_type, ipa_protocol_vals,
 271                                            "unknown 0x%02x"));
 272
 273                 /*
 274                  * The IPA header is different depending on the transport protocol.
 275                  * With UDP there seems to be a fourth byte for the IPA header.
 276                  * We attempt to detect this by checking if the length from the
 277                  * header + four bytes of the IPA header equals the remaining size.
 278                  */
 279                 if ((pinfo->ipproto == IP_PROTO_UDP) && (len + 4 == remaining)) {
 280                         header_length++;
 281                 }
 282
 283                 if (tree) {
 284                         ti = proto_tree_add_protocol_format(tree, proto_ipa,
 285                                         tvb, offset, len+header_length,
 286                                         "IPA protocol ip.access, type: %s",
 287                                         val_to_str(msg_type, ipa_protocol_vals,
 288                                                    "unknown 0x%02x"));
 289                         ipa_tree = proto_item_add_subtree(ti, ett_ipa);
 290                         proto_tree_add_item(ipa_tree, hf_ipa_data_len,
 291                                             tvb, offset, 2, ENC_BIG_ENDIAN);
 292                         proto_tree_add_item(ipa_tree, hf_ipa_protocol,
 293                                             tvb, offset+2, 1, ENC_BIG_ENDIAN);
 294                 }
 295
 296                 next_tvb = tvb_new_subset(tvb, offset+header_length, len, len);
 297
 298                 switch (msg_type) {
 299                 case ABISIP_OML:
 300                         /* hand this off to the standard A-bis OML dissector */
 301                         if (sub_handles[SUB_OML])
 302                                 call_dissector(sub_handles[SUB_OML], next_tvb,
 303                                                  pinfo, tree);
 304                         break;
 305                 case ABISIP_IPACCESS:
 306                         dissect_ipaccess(next_tvb, pinfo, tree);
 307                         break;
 308                 case AIP_SCCP:
 309                         /* hand this off to the standard SCCP dissector */
 310                         call_dissector(sub_handles[SUB_SCCP], next_tvb, pinfo, tree);
 311                         break;
 312                 case IPA_MGCP:
 313                         /* hand this off to the standard MGCP dissector */
 314                         call_dissector(sub_handles[SUB_MGCP], next_tvb, pinfo, tree);
 315                         break;
 316                 case OSMO_EXT:
 317                         dissect_osmo(next_tvb, pinfo, ipa_tree, tree);
 318                         break;
 319                 case HSL_DEBUG:
 320                         if (tree) {
 321                                 proto_tree_add_item(ipa_tree, hf_ipa_hsl_debug,
 322                                                     next_tvb, 0, len, ENC_ASCII|ENC_NA);
 323                                 if (global_ipa_in_root == TRUE)
 324                                         proto_tree_add_item(tree, hf_ipa_hsl_debug,
 325                                                             next_tvb, 0, len, ENC_ASCII|ENC_NA);
 326                         }
 327                         if (global_ipa_in_info == TRUE)
 328                                 col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
 329                                                 tvb_get_stringz(next_tvb, 0, NULL));
 330                         break;
 331                 default:
 332                         if (msg_type < ABISIP_RSL_MAX) {
 333                                 /* hand this off to the standard A-bis RSL dissector */
 334                                 call_dissector(sub_handles[SUB_RSL], next_tvb, pinfo, tree);
 335                         }
 336                         break;
 337                 }
 338                 offset += len + header_length;
 339         }
 340 }
 341
 342 void proto_reg_handoff_gsm_ipa(void);
 343
 344 void proto_register_ipa(void)
 345 {
 346         module_t *ipa_module;
 347
 348         static hf_register_info hf[] = {
 349                 {&hf_ipa_data_len,
 350                  {"DataLen", "ipa.data_len",
 351                   FT_UINT16, BASE_DEC, NULL, 0x0,
 352                   "The length of the data (in bytes)", HFILL}
 353                  },
 354                 {&hf_ipa_protocol,
 355                  {"Protocol", "ipa.protocol",
 356                   FT_UINT8, BASE_HEX, VALS(ipa_protocol_vals), 0x0,
 357                   "The IPA Sub-Protocol", HFILL}
 358                  },
 359                 {&hf_ipa_hsl_debug,
 360                  {"Debug Message", "ipa.hsl_debug",
 361                   FT_STRING, BASE_NONE, NULL, 0,
 362                   "Hay Systems Limited debug message", HFILL}
 363                 },
 364                 {&hf_ipa_osmo_proto,
 365                  {"Osmo ext protocol", "ipa.osmo.protocol",
 366                   FT_UINT8, BASE_HEX, VALS(ipa_osmo_proto_vals), 0x0,
 367                   "The osmo extension protocol", HFILL}
 368                 },
 369
 370                 {&hf_ipa_osmo_ctrl_data,
 371                  {"CTRL data", "ipa.ctrl.data",
 372                   FT_STRING, BASE_NONE, NULL, 0x0,
 373                   "Control interface data", HFILL}
 374                 },
 375
 376         };
 377         static hf_register_info hf_ipa[] = {
 378                 {&hf_ipaccess_msgtype,
 379                  {"MessageType", "ipaccess.msg_type",
 380                   FT_UINT8, BASE_HEX, VALS(ipaccess_msgtype_vals), 0x0,
 381                   "Type of ip.access messsage", HFILL}
 382                  },
 383                 {&hf_ipaccess_attr_tag,
 384                  {"Tag", "ipaccess.attr_tag",
 385                   FT_UINT8, BASE_HEX, VALS(ipaccess_idtag_vals), 0x0,
 386                   "Attribute Tag", HFILL}
 387                  },
 388                 {&hf_ipaccess_attr_string,
 389                  {"String", "ipaccess.attr_string",
 390                   FT_STRING, BASE_NONE, NULL, 0x0,
 391                   "String attribute", HFILL}
 392                  },
 393         };
 394
 395         static gint *ett[] = {
 396                 &ett_ipa,
 397                 &ett_ipaccess,
 398         };
 399
 400         proto_ipa =
 401             proto_register_protocol("GSM over IP protocol as used by ip.access",
 402                                     "GSM over IP", "gsm_ipa");
 403         proto_ipaccess =
 404             proto_register_protocol("GSM over IP ip.access CCM sub-protocol",
 405                                     "IPA", "ipaccess");
 406
 407         proto_register_field_array(proto_ipa, hf, array_length(hf));
 408         proto_register_field_array(proto_ipaccess, hf_ipa, array_length(hf_ipa));
 409         proto_register_subtree_array(ett, array_length(ett));
 410
 411         register_dissector("gsm_ipa", dissect_ipa, proto_ipa);
 412
 413         /* Register table for subdissectors */
 414         osmo_dissector_table = register_dissector_table("ipa.osmo.protocol",
 415                                         "ip.access Protocol", FT_UINT8, BASE_DEC);
 416
 417
 418         range_convert_str(&global_ipa_tcp_ports, IPA_TCP_PORTS, MAX_TCP_PORT);
 419         range_convert_str(&global_ipa_udp_ports, IPA_UDP_PORTS, MAX_UDP_PORT);
 420         ipa_module = prefs_register_protocol(proto_ipa,
 421                                              proto_reg_handoff_gsm_ipa);
 422
 423         prefs_register_range_preference(ipa_module, "tcp_ports",
 424                                         "GSM IPA TCP Port(s)",
 425                                         "Set the port(s) for ip.access IPA"
 426                                         " (default: " IPA_TCP_PORTS ")",
 427                                         &global_ipa_tcp_ports, MAX_TCP_PORT);
 428         prefs_register_range_preference(ipa_module, "udp_ports",
 429                                         "GSM IPA UDP Port(s)",
 430                                         "Set the port(s) for ip.access IPA"
 431                                         " (default: " IPA_UDP_PORTS ")",
 432                                         &global_ipa_udp_ports, MAX_UDP_PORT);
 433
 434         prefs_register_bool_preference(ipa_module, "hsl_debug_in_root_tree",
 435                                         "HSL Debug messages in root protocol tree",
 436                                         NULL, &global_ipa_in_root);
 437         prefs_register_bool_preference(ipa_module, "hsl_debug_in_info",
 438                                         "HSL Debug messages in INFO column",
 439                                         NULL, &global_ipa_in_info);
 440 }
 441
 442 static void ipa_tcp_delete_callback(guint32 port)
 443 {
 444         if (port)
 445                 dissector_delete_uint("tcp.port", port, ipa_handle);
 446 }
 447
 448 static void ipa_udp_delete_callback(guint32 port)
 449 {
 450         if (port)
 451                 dissector_delete_uint("udp.port", port, ipa_handle);
 452 }
 453
 454 static void ipa_tcp_add_callback(guint32 port)
 455 {
 456         if (port)
 457                 dissector_add_uint("tcp.port", port, ipa_handle);
 458 }
 459
 460 static void ipa_udp_add_callback(guint32 port)
 461 {
 462         if (port)
 463                 dissector_add_uint("udp.port", port, ipa_handle);
 464 }
 465
 466 void proto_reg_handoff_gsm_ipa(void)
 467 {
 468         static gboolean ipa_initialized = FALSE;
 469         static range_t *ipa_tcp_ports, *ipa_udp_ports;
 470
 471         if (!ipa_initialized) {
 472                 sub_handles[SUB_RSL] = find_dissector("gsm_abis_rsl");
 473                 sub_handles[SUB_OML] = find_dissector("gsm_abis_oml");
 474                 sub_handles[SUB_SCCP] = find_dissector("sccp");
 475                 sub_handles[SUB_MGCP] = find_dissector("mgcp");
 476                 sub_handles[SUB_DATA] = find_dissector("data");
 477
 478                 ipa_handle = create_dissector_handle(dissect_ipa, proto_ipa);
 479                 ipa_initialized = TRUE;
 480         } else {
 481                 range_foreach(ipa_tcp_ports, ipa_tcp_delete_callback);
 482                 g_free(ipa_tcp_ports);
 483                 range_foreach(ipa_udp_ports, ipa_udp_delete_callback);
 484                 g_free(ipa_udp_ports);
 485         }
 486
 487         ipa_tcp_ports = range_copy(global_ipa_tcp_ports);
 488         ipa_udp_ports = range_copy(global_ipa_udp_ports);
 489
 490         range_foreach(ipa_tcp_ports, ipa_tcp_add_callback);
 491         range_foreach(ipa_udp_ports, ipa_udp_add_callback);
 492 }