epan/dissectors/packet-ipdc.c

   1 /* packet-ipdc.c
   2  * Routines for IP Device Control (SS7 over IP) dissection
   3  * Copyright Lucent Technologies 2004
   4  * Josh Bailey <joshbailey@lucent.com> and Ruud Linders <ruud@lucent.com>
   5  *
   6  * Using IPDC spec 0.20.2
   7  *
   8  * $Id$
   9  *
  10  * Wireshark - Network traffic analyzer
  11  * By Gerald Combs <gerald@wireshark.org>
  12  * Copyright 1998 Gerald Combs
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version 2
  17  * of the License, or (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36
  37 #include <glib.h>
  38 #include <math.h>
  39
  40 #include <epan/packet.h>
  41 #include <epan/emem.h>
  42 #include "packet-ipdc.h"
  43 #include "packet-tcp.h"
  44 #include <epan/ipproto.h>
  45 #include <epan/prefs.h>
  46
  47 static int proto_ipdc = -1;
  48 static int hf_ipdc_nr = -1;
  49 static int hf_ipdc_ns = -1;
  50 static int hf_ipdc_payload_len = -1;
  51 static int hf_ipdc_protocol_id = -1;
  52 static int hf_ipdc_trans_id_size = -1;
  53 static int hf_ipdc_trans_id = -1;
  54 static int hf_ipdc_message_code = -1;
  55
  56 static gint ett_ipdc = -1;
  57 static gint ett_ipdc_tag = -1;
  58
  59 static gboolean ipdc_desegment = TRUE;
  60 static guint ipdc_port_pref = TCP_PORT_IPDC;
  61 static gboolean new_packet = FALSE;
  62
  63 static dissector_handle_t q931_handle;
  64
  65 void proto_reg_handoff_ipdc(void);
  66
  67
  68 static guint
  69 get_ipdc_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
  70 {
  71         /* lower 10 bits only */
  72         guint raw_len = (tvb_get_ntohs(tvb,offset+2) & 0x03FF);
  73
  74         return raw_len + 4;
  75 }
  76
  77 static void
  78 dissect_ipdc_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  79 {
  80         proto_item *ti;
  81         proto_tree *ipdc_tree;
  82         proto_item *ipdc_tag;
  83         proto_tree *tag_tree;
  84         tvbuff_t *q931_tvb;
  85
  86         const char *des;
  87         const char *enum_val = "";
  88         char tmp_tag_text[IPDC_STR_LEN + 1];
  89         const value_string *val_ptr;
  90         guint32 type;
  91         guint len;
  92         guint i;
  93         guint status;
  94         gshort tag;
  95         guint32 tmp_tag;
  96
  97         gshort nr = tvb_get_guint8(tvb,0);
  98         gshort ns = tvb_get_guint8(tvb,1);
  99         guint payload_len = get_ipdc_pdu_len(pinfo,tvb,0);
 100
 101         gshort protocol_id;
 102         gshort trans_id_size;
 103         guint32 trans_id;
 104         guint16 message_code;
 105         guint16 offset;
 106
 107         /* display IPDC protocol ID */
 108         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 109                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "IPDC");
 110
 111         /* short frame... */
 112         if (payload_len < 4)
 113                 return;
 114
 115         /* clear info column and display send/receive sequence numbers */
 116         if (check_col(pinfo->cinfo, COL_INFO)) {
 117                 if (new_packet == TRUE) {
 118                         col_clear(pinfo->cinfo, COL_INFO);
 119                         new_packet = FALSE;
 120                 }
 121                 col_append_fstr(pinfo->cinfo, COL_INFO, "r=%u s=%u ",
 122                 nr, ns);
 123         }
 124
 125         if (payload_len == 4) {
 126                 if (!tree)
 127                         return;
 128
 129                 ti = proto_tree_add_item(tree, proto_ipdc, tvb, 0, -1, FALSE);
 130                 ipdc_tree = proto_item_add_subtree(ti, ett_ipdc);
 131                 proto_tree_add_item(ipdc_tree, hf_ipdc_nr, tvb, 0, 1, nr);
 132                 proto_tree_add_item(ipdc_tree, hf_ipdc_ns, tvb, 1, 1, ns);
 133                 proto_tree_add_uint(ipdc_tree, hf_ipdc_payload_len, tvb, 2, 2,
 134                         payload_len);
 135
 136                 return;
 137         }
 138
 139         /* IPDC tags present - display message code and trans. ID */
 140         protocol_id = tvb_get_guint8(tvb,4);
 141         trans_id_size = TRANS_ID_SIZE_IPDC; /* tvb_get_guint8(tvb,5); */
 142         trans_id = tvb_get_ntohl(tvb,6);
 143         message_code = tvb_get_ntohs(tvb,6+trans_id_size);
 144         offset = 6 + trans_id_size + 2; /* past message_code */
 145
 146         if (check_col(pinfo->cinfo, COL_INFO))
 147                 col_append_fstr(pinfo->cinfo, COL_INFO,
 148                         "TID=%x %s ",
 149                         trans_id,
 150                         val_to_str(message_code, message_code_vals,
 151                         TEXT_UNDEFINED));
 152
 153         if (!tree)
 154                 return;
 155
 156         ti = proto_tree_add_item(tree, proto_ipdc, tvb, 0, -1, FALSE);
 157         ipdc_tree = proto_item_add_subtree(ti, ett_ipdc);
 158
 159         proto_tree_add_item(ipdc_tree, hf_ipdc_nr, tvb, 0, 1, nr);
 160         proto_tree_add_item(ipdc_tree, hf_ipdc_ns, tvb, 1, 1, ns);
 161         proto_tree_add_uint(ipdc_tree, hf_ipdc_payload_len, tvb,
 162                 2, 2, payload_len);
 163
 164         proto_tree_add_item(ipdc_tree, hf_ipdc_protocol_id, tvb,
 165                 4, 1, protocol_id);
 166         proto_tree_add_item(ipdc_tree, hf_ipdc_trans_id_size, tvb,
 167                 5, 1, trans_id_size);
 168         proto_tree_add_item(ipdc_tree, hf_ipdc_trans_id, tvb,
 169                 6, trans_id_size, trans_id);
 170         proto_tree_add_item(ipdc_tree, hf_ipdc_message_code, tvb,
 171                 6 + trans_id_size + 1, 1, message_code);
 172
 173         ipdc_tag = proto_tree_add_text(ipdc_tree, tvb, offset,
 174         payload_len - offset, "IPDC tags");
 175         tag_tree = proto_item_add_subtree(ipdc_tag, ett_ipdc_tag);
 176
 177         /* iterate through tags. first byte is tag, second is length,
 178            in bytes, following is tag data. tag of 0x0 should be
 179            end of tags. */
 180         for (;;) {
 181                 tag = tvb_get_guint8(tvb, offset);
 182
 183                 if (tag == 0x0) {
 184                         if (offset == payload_len - 1) {
 185                                 proto_tree_add_text(tag_tree, tvb,
 186                                 offset, 1, "end of tags");
 187                         } else {
 188                                 proto_tree_add_text(tag_tree, tvb,
 189                                 offset, 1, "data trailing end of tags");
 190                         }
 191
 192                         break;
 193                 }
 194
 195                 len = tvb_get_guint8(tvb,offset+1);
 196                 des = val_to_str(tag, tag_description, TEXT_UNDEFINED);
 197                 /* lookup tag type */
 198                 for (i = 0; (ipdc_tag_types[i].tag != tag &&
 199                         ipdc_tag_types[i].type != IPDC_UNKNOWN); i++)
 200                 ;
 201                 type = ipdc_tag_types[i].type;
 202
 203                 tmp_tag = 0;
 204
 205                 switch (type) {
 206                         /* simple IPDC_ASCII strings */
 207                         case IPDC_ASCII:
 208                                 DISSECTOR_ASSERT(len<=IPDC_STR_LEN);
 209                                 tvb_memcpy(tvb, tmp_tag_text, offset+2, len);
 210                                 tmp_tag_text[len] = 0;
 211                                 proto_tree_add_text(tag_tree, tvb, offset,
 212                                 len + 2, "0x%2.2x: %s: %s", tag, des,
 213                                 tmp_tag_text);
 214                         break;
 215
 216                         /* unsigned integers, or bytes */
 217                         case IPDC_UINT:
 218                         case IPDC_BYTE:
 219                                 for (i = 0; i < len; i++)
 220                                         tmp_tag += tvb_get_guint8(tvb,
 221                                                 offset + 2 + i) * (guint32)
 222                                                         pow(256, len - (i + 1));
 223
 224                                 if (len == 1)
 225                                         enum_val =
 226                                                 val_to_str(IPDC_TAG(tag) +
 227                                                 tmp_tag,
 228                                                 tag_enum_type, TEXT_UNDEFINED);
 229
 230                                 if (len == 1 &&
 231                                         strcmp(enum_val, TEXT_UNDEFINED) != 0) {
 232                                         proto_tree_add_text(tag_tree, tvb,
 233                                                 offset, len + 2,
 234                                                 "0x%2.2x: %s: %s",
 235                                                 tag, des, enum_val);
 236                                 } else {
 237                                         proto_tree_add_text(tag_tree, tvb,
 238                                                 offset, len + 2,
 239                                                 "0x%2.2x: %s: %u",
 240                                                 tag, des, tmp_tag);
 241                                 }
 242                         break;
 243
 244                         /* IP addresses */
 245                         case IPDC_IPA:
 246                                 switch (len) {
 247                                         case 4:
 248                                                 g_snprintf(tmp_tag_text,
 249                                                 IPDC_STR_LEN,
 250                                                 "%u.%u.%u.%u",
 251                                                 tvb_get_guint8(tvb, offset + 2),
 252                                                 tvb_get_guint8(tvb, offset + 3),
 253                                                 tvb_get_guint8(tvb, offset + 4),
 254                                                 tvb_get_guint8(tvb, offset + 5)
 255                                                 );
 256                                         break;
 257
 258                                         case 6:
 259                                                 g_snprintf(tmp_tag_text,
 260                                                 IPDC_STR_LEN,
 261                                                 "%u.%u.%u.%u:%u",
 262                                                 tvb_get_guint8(tvb, offset + 2),
 263                                                 tvb_get_guint8(tvb, offset + 3),
 264                                                 tvb_get_guint8(tvb, offset + 4),
 265                                                 tvb_get_guint8(tvb, offset + 5),
 266                                                 tvb_get_ntohs(tvb, offset + 6));
 267                                         break;
 268
 269                                         default:
 270                                                 g_snprintf(tmp_tag_text,
 271                                                 IPDC_STR_LEN,
 272                                                 "Invalid IP address length %u",
 273                                                  len);
 274                                 }
 275
 276                                 proto_tree_add_text(tag_tree, tvb,
 277                                         offset, len + 2,
 278                                         "0x%2.2x: %s: %s",
 279                                         tag, des, tmp_tag_text);
 280                         break;
 281
 282                         /* Line status arrays */
 283                         case IPDC_LINESTATUS:
 284                         case IPDC_CHANNELSTATUS:
 285                                 proto_tree_add_text(tag_tree, tvb, offset,
 286                                 len + 2, "0x%2.2x: %s", tag, des);
 287                                 val_ptr = (type == IPDC_LINESTATUS) ?
 288                                         line_status_vals : channel_status_vals;
 289
 290                                 for (i = 0; i < len; i++) {
 291                                         status = tvb_get_guint8(tvb,offset+2+i);
 292
 293                                         proto_tree_add_text(tag_tree, tvb,
 294                                                 offset + 2 + i, 1,
 295                                                 " %.2u: %.2x (%s)",
 296                                                 i + 1, status,
 297                                                 val_to_str(status,
 298                                                 val_ptr,
 299                                                 TEXT_UNDEFINED));
 300                                 }
 301                         break;
 302
 303                         case IPDC_Q931:
 304                                 q931_tvb =
 305                                         tvb_new_subset(tvb, offset+2, len, len);
 306                                 call_dissector(q931_handle,q931_tvb,pinfo,tree);
 307                         break;
 308
 309                         case IPDC_ENCTYPE:
 310                                 proto_tree_add_text(tag_tree, tvb,
 311                                         offset, len + 2,
 312                                         "0x%2.2x: %s: %s",
 313                                         tag, des, val_to_str(
 314                                         tvb_get_guint8(tvb,offset+2),
 315                                         encoding_type_vals,
 316                                         TEXT_UNDEFINED));
 317
 318                                 if (len == 2) {
 319                                         proto_tree_add_text(tag_tree, tvb,
 320                                                 offset, len + 2,
 321                                                 "0x%2.2x: %s: %u",
 322                                                 tag, des,
 323                                                 tvb_get_guint8(tvb,offset+3));
 324                                 }
 325                         break;
 326
 327                         /* default */
 328                         default:
 329                                 proto_tree_add_text(tag_tree, tvb, offset,
 330                                 len + 2, "0x%2.2x: %s", tag, des);
 331                 } /* switch */
 332
 333                 offset += len + 2;
 334         }
 335 }
 336
 337 static void
 338 dissect_ipdc_tcp_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 339 {
 340         dissect_ipdc_common(tvb, pinfo, tree);
 341 }
 342
 343 static void
 344 dissect_ipdc_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 345 {
 346         new_packet = TRUE;
 347         tcp_dissect_pdus(tvb, pinfo, tree, ipdc_desegment, 4,
 348                 get_ipdc_pdu_len, dissect_ipdc_tcp_pdu);
 349 }
 350
 351 void
 352 proto_register_ipdc(void)
 353 {
 354
 355         static hf_register_info hf[] = {
 356                 { &hf_ipdc_nr,
 357                         { "N(r)",       "ipdc.nr",
 358                         FT_UINT8, BASE_DEC, NULL, 0x0,
 359                         "Receive sequence number", HFILL }
 360                 },
 361
 362                 { &hf_ipdc_ns,
 363                         { "N(s)",       "ipdc.ns",
 364                         FT_UINT8, BASE_DEC, NULL, 0x0,
 365                         "Transmit sequence number", HFILL }
 366                 },
 367
 368                 { &hf_ipdc_payload_len,
 369                         { "Payload length",     "ipdc.length",
 370                         FT_UINT16, BASE_DEC, NULL, 0x0,
 371                         "Payload length", HFILL }
 372                 },
 373
 374                 { &hf_ipdc_protocol_id,
 375                         { "Protocol ID",        "ipdc.protocol_id",
 376                         FT_UINT8, BASE_HEX, NULL, 0x0,
 377                         "Protocol ID", HFILL }
 378                 },
 379
 380                 { &hf_ipdc_trans_id_size,
 381                         { "Transaction ID size",        "ipdc.trans_id_size",
 382                         FT_UINT8, BASE_DEC, NULL, 0x0,
 383                         "Transaction ID size", HFILL }
 384                 },
 385
 386                 { &hf_ipdc_trans_id,
 387                         { "Transaction ID",     "ipdc.trans_id",
 388                         FT_BYTES, BASE_HEX, NULL, 0x0,
 389                         "Transaction ID", HFILL }
 390                 },
 391
 392                 { &hf_ipdc_message_code,
 393                         { "Message code",       "ipdc.message_code",
 394                         FT_UINT16, BASE_HEX, VALS(message_code_vals), 0x0,
 395                         "Message Code", HFILL }
 396                 },
 397         };
 398
 399         static gint *ett[] = {
 400                 &ett_ipdc,
 401                 &ett_ipdc_tag,
 402         };
 403
 404         module_t *ipdc_module;
 405
 406         proto_ipdc = proto_register_protocol("IP Device Control (SS7 over IP)",
 407             "IPDC", "ipdc");
 408         proto_register_field_array(proto_ipdc, hf, array_length(hf));
 409         proto_register_subtree_array(ett, array_length(ett));
 410
 411         ipdc_module = prefs_register_protocol(proto_ipdc, proto_reg_handoff_ipdc);
 412         prefs_register_bool_preference(ipdc_module, "desegment_ipdc_messages",
 413                 "Reassemble IPDC messages spanning multiple TCP segments",
 414                 "Whether the IPDC dissector should reassemble messages spanning multiple TCP segments."
 415                 " To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
 416                 &ipdc_desegment);
 417         prefs_register_uint_preference(ipdc_module, "tcp.port",
 418                 "IPDC monitoring port",
 419                 "Set the IPDC monitoring port", 10,
 420                 &ipdc_port_pref);
 421 }
 422
 423 void
 424 proto_reg_handoff_ipdc(void)
 425 {
 426         static guint last_ipdc_port_pref = 0;
 427         static dissector_handle_t ipdc_tcp_handle = NULL;
 428
 429         if (ipdc_tcp_handle) {
 430                 dissector_delete("tcp.port", last_ipdc_port_pref,
 431                         ipdc_tcp_handle);
 432         } else {
 433                 ipdc_tcp_handle =
 434                         create_dissector_handle(dissect_ipdc_tcp, proto_ipdc);
 435                 q931_handle = find_dissector("q931");
 436         }
 437
 438         last_ipdc_port_pref = ipdc_port_pref;
 439         dissector_add("tcp.port", ipdc_port_pref, ipdc_tcp_handle);
 440 }