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