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