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  * Ethereal - Network traffic analyzer
  11  * By Gerald Combs <gerald@ethereal.com>
  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 #ifdef NEED_SNPRINTF_H
  41 # include "snprintf.h"
  42 #endif
  43
  44 #include <epan/packet.h>
  45 #include "packet-ipdc.h"
  46 #include "packet-tcp.h"
  47 #include <epan/packet.h>
  48 #include <epan/ipproto.h>
  49 #include <epan/prefs.h>
  50
  51 static int proto_ipdc = -1;
  52 static int hf_ipdc_nr = -1;
  53 static int hf_ipdc_ns = -1;
  54 static int hf_ipdc_payload_len = -1;
  55 static int hf_ipdc_protocol_id = -1;
  56 static int hf_ipdc_trans_id_size = -1;
  57 static int hf_ipdc_trans_id = -1;
  58 static int hf_ipdc_message_code = -1;
  59
  60 static gint ett_ipdc = -1;
  61 static gint ett_ipdc_tag = -1;
  62
  63 static gboolean ipdc_desegment = TRUE;
  64 static gint ipdc_port_pref = TCP_PORT_IPDC;
  65 static gboolean new_packet = FALSE;
  66
  67 static dissector_handle_t q931_handle;
  68
  69 void proto_reg_handoff_ipdc(void);
  70
  71
  72 static guint
  73 get_ipdc_pdu_len(tvbuff_t *tvb, int offset)
  74 {
  75         return tvb_get_ntohs(tvb,offset+2)+4;
  76 }
  77
  78 static void
  79 dissect_ipdc_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  80 {
  81         proto_item *ti;
  82         proto_tree *ipdc_tree;
  83         proto_item *ipdc_tag;
  84         proto_tree *tag_tree;
  85         tvbuff_t *q931_tvb;
  86
  87         char *des;
  88         char *enum_val;
  89         char *tmp_str;
  90         char tmp_tag_text[IPDC_STR_LEN + 1];
  91         const value_string *val_ptr;
  92         guint32 type;
  93         guint len;
  94         guint i;
  95         guint status;
  96         gshort tag;
  97         guint32 tmp_tag;
  98
  99         gshort nr = tvb_get_guint8(tvb,0);
 100         gshort ns = tvb_get_guint8(tvb,1);
 101         guint16 payload_len = (guint16) get_ipdc_pdu_len(tvb,0);
 102
 103         gshort protocol_id;
 104         gshort trans_id_size;
 105         guint32 trans_id;
 106         guint16 message_code;
 107         guint16 offset;
 108
 109         /* display IPDC protocol ID */
 110         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 111                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "IPDC");
 112
 113         /* short frame... */
 114         if (payload_len < 4)
 115                 return;
 116
 117         /* clear info column and display send/receive sequence numbers */
 118         if (check_col(pinfo->cinfo, COL_INFO)) {
 119                 if (new_packet == TRUE) {
 120                         col_clear(pinfo->cinfo, COL_INFO);
 121                         new_packet = FALSE;
 122                 }
 123                 col_append_fstr(pinfo->cinfo, COL_INFO, "r=%u s=%u ",
 124                 nr, ns);
 125         }
 126
 127         if (payload_len == 4) {
 128                 if (!tree)
 129                         return;
 130
 131                 ti = proto_tree_add_item(tree, proto_ipdc, tvb, 0, -1, FALSE);
 132                 ipdc_tree = proto_item_add_subtree(ti, ett_ipdc);
 133                 proto_tree_add_item(ipdc_tree, hf_ipdc_nr, tvb, 0, 1, nr);
 134                 proto_tree_add_item(ipdc_tree, hf_ipdc_ns, tvb, 1, 1, ns);
 135                 proto_tree_add_uint(ipdc_tree, hf_ipdc_payload_len, tvb, 2, 2,
 136                         payload_len);
 137
 138                 return;
 139         }
 140
 141         /* IPDC tags present - display message code and trans. ID */
 142         protocol_id = tvb_get_guint8(tvb,4);
 143         trans_id_size = TRANS_ID_SIZE_IPDC;
 144         trans_id = tvb_get_ntohl(tvb,6);
 145         message_code = tvb_get_ntohs(tvb,6+trans_id_size);
 146         offset = 6 + trans_id_size + 2; /* past message_code */
 147
 148         if (check_col(pinfo->cinfo, COL_INFO))
 149                 col_append_fstr(pinfo->cinfo, COL_INFO,
 150                         "TID=%x %s ",
 151                         trans_id,
 152                         val_to_str(message_code, message_code_vals,
 153                         TEXT_UNDEFINED));
 154
 155         if (!tree)
 156                 return;
 157
 158         ti = proto_tree_add_item(tree, proto_ipdc, tvb, 0, -1, FALSE);
 159         ipdc_tree = proto_item_add_subtree(ti, ett_ipdc);
 160
 161         proto_tree_add_item(ipdc_tree, hf_ipdc_nr, tvb, 0, 1, nr);
 162         proto_tree_add_item(ipdc_tree, hf_ipdc_ns, tvb, 1, 1, ns);
 163         proto_tree_add_uint(ipdc_tree, hf_ipdc_payload_len, tvb,
 164                 2, 2, payload_len);
 165
 166         proto_tree_add_item(ipdc_tree, hf_ipdc_protocol_id, tvb,
 167                 4, 1, protocol_id);
 168         proto_tree_add_item(ipdc_tree, hf_ipdc_trans_id_size, tvb,
 169                 5, 1, trans_id_size);
 170         proto_tree_add_item(ipdc_tree, hf_ipdc_trans_id, tvb,
 171                 6, trans_id_size, trans_id);
 172         proto_tree_add_item(ipdc_tree, hf_ipdc_message_code, tvb,
 173                 6 + trans_id_size + 1, 1, message_code);
 174
 175         ipdc_tag = proto_tree_add_text(ipdc_tree, tvb, offset,
 176         payload_len - offset, "IPDC tags");
 177         tag_tree = proto_item_add_subtree(ipdc_tag, ett_ipdc_tag);
 178
 179         /* iterate through tags. first byte is tag, second is length,
 180            in bytes, following is tag data. tag of 0x0 should be
 181            end of tags. */
 182         for (;;) {
 183                 tag = tvb_get_guint8(tvb, offset);
 184
 185                 if (tag == 0x0) {
 186                         if (offset == payload_len - 1) {
 187                                 proto_tree_add_text(tag_tree, tvb,
 188                                 offset, 1, "end of tags");
 189                         } else {
 190                                 proto_tree_add_text(tag_tree, tvb,
 191                                 offset, 1, "data trailing end of tags");
 192                         }
 193
 194                         break;
 195                 }
 196
 197                 len = tvb_get_guint8(tvb,offset+1);
 198                 des = val_to_str(tag, tag_description, TEXT_UNDEFINED);
 199                 /* lookup tag type */
 200                 for (i = 0; (ipdc_tag_types[i].tag != tag &&
 201                         ipdc_tag_types[i].type != IPDC_UNKNOWN); i++)
 202                 ;
 203                 type = ipdc_tag_types[i].type;
 204
 205                 tmp_tag = 0;
 206
 207                 switch (type) {
 208                         /* simple IPDC_ASCII strings */
 209                         case IPDC_ASCII:
 210                                 tmp_str = tvb_memdup(tvb, offset + 2, len);
 211                                 strncpy(tmp_tag_text, tmp_str, len);
 212                                 tmp_tag_text[len] = 0;
 213                                 free(tmp_str);
 214                                 proto_tree_add_text(tag_tree, tvb, offset,
 215                                 len + 2, "0x%2.2x: %s: %s", tag, des,
 216                                 tmp_tag_text);
 217                         break;
 218
 219                         /* unsigned integers, or bytes */
 220                         case IPDC_UINT:
 221                         case IPDC_BYTE:
 222                                 for (i = 0; i < len; i++)
 223                                         tmp_tag += tvb_get_guint8(tvb,
 224                                                 offset + 2 + i) * (guint32)
 225                                                         pow(256, len - (i + 1));
 226
 227                                 if (len == 1)
 228                                         enum_val =
 229                                                 val_to_str(IPDC_TAG(tag) +
 230                                                 tmp_tag,
 231                                                 tag_enum_type, TEXT_UNDEFINED);
 232
 233                                 if (len == 1 &&
 234                                         strcmp(enum_val, TEXT_UNDEFINED) != 0) {
 235                                         proto_tree_add_text(tag_tree, tvb,
 236                                                 offset, len + 2,
 237                                                 "0x%2.2x: %s: %s",
 238                                                 tag, des, enum_val);
 239                                 } else {
 240                                         proto_tree_add_text(tag_tree, tvb,
 241                                                 offset, len + 2,
 242                                                 "0x%2.2x: %s: %u",
 243                                                 tag, des, tmp_tag);
 244                                 }
 245                         break;
 246
 247                         /* IP addresses */
 248                         case IPDC_IPA:
 249                                 switch (len) {
 250                                         case 4:
 251                                                 g_snprintf(tmp_tag_text,
 252                                                 IPDC_STR_LEN,
 253                                                 "%u.%u.%u.%u",
 254                                                 tvb_get_guint8(tvb, offset + 2),
 255                                                 tvb_get_guint8(tvb, offset + 3),
 256                                                 tvb_get_guint8(tvb, offset + 4),
 257                                                 tvb_get_guint8(tvb, offset + 5)
 258                                                 );
 259                                         break;
 260
 261                                         case 6:
 262                                                 g_snprintf(tmp_tag_text,
 263                                                 IPDC_STR_LEN,
 264                                                 "%u.%u.%u.%u:%u",
 265                                                 tvb_get_guint8(tvb, offset + 2),
 266                                                 tvb_get_guint8(tvb, offset + 3),
 267                                                 tvb_get_guint8(tvb, offset + 4),
 268                                                 tvb_get_guint8(tvb, offset + 5),
 269                                                 tvb_get_ntohs(tvb, offset + 6));
 270                                         break;
 271
 272                                         default:
 273                                                 g_snprintf(tmp_tag_text,
 274                                                 IPDC_STR_LEN,
 275                                                 "Invalid IP address length %u",
 276                                                  len);
 277                                 }
 278
 279                                 proto_tree_add_text(tag_tree, tvb,
 280                                         offset, len + 2,
 281                                         "0x%2.2x: %s: %s",
 282                                         tag, des, tmp_tag_text);
 283                         break;
 284
 285                         /* Line status arrays */
 286                         case IPDC_LINESTATUS:
 287                         case IPDC_CHANNELSTATUS:
 288                                 proto_tree_add_text(tag_tree, tvb, offset,
 289                                 len + 2, "0x%2.2x: %s", tag, des);
 290                                 val_ptr = (type == IPDC_LINESTATUS) ?
 291                                         line_status_vals : channel_status_vals;
 292
 293                                 for (i = 0; i < len; i++) {
 294                                         status = tvb_get_guint8(tvb,offset+2+i);
 295
 296                                         proto_tree_add_text(tag_tree, tvb,
 297                                                 offset + 2 + i, 1,
 298                                                 " %.2u: %.2x (%s)",
 299                                                 i + 1, status,
 300                                                 val_to_str(status,
 301                                                 val_ptr,
 302                                                 TEXT_UNDEFINED));
 303                                 }
 304                         break;
 305
 306                         case IPDC_Q931:
 307                                 q931_tvb =
 308                                         tvb_new_subset(tvb, offset+2, len, len);
 309                                 call_dissector(q931_handle,q931_tvb,pinfo,tree);
 310                         break;
 311
 312                         case IPDC_ENCTYPE:
 313                                 proto_tree_add_text(tag_tree, tvb,
 314                                         offset, len + 2,
 315                                         "0x%2.2x: %s: %s",
 316                                         tag, des, val_to_str(
 317                                         tvb_get_guint8(tvb,offset+2),
 318                                         encoding_type_vals,
 319                                         TEXT_UNDEFINED));
 320
 321                                 if (len == 2) {
 322                                         proto_tree_add_text(tag_tree, tvb,
 323                                                 offset, len + 2,
 324                                                 "0x%2.2x: %s: %u",
 325                                                 tag, des,
 326                                                 tvb_get_guint8(tvb,offset+3));
 327                                 }
 328                         break;
 329
 330                         /* default */
 331                         default:
 332                                 proto_tree_add_text(tag_tree, tvb, offset,
 333                                 len + 2, "0x%2.2x: %s", tag, des);
 334                 } /* switch */
 335
 336                 offset += len + 2;
 337         }
 338 }
 339
 340 static void
 341 dissect_ipdc_tcp_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 342 {
 343         dissect_ipdc_common(tvb, pinfo, tree);
 344 }
 345
 346 static void
 347 dissect_ipdc_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 348 {
 349         new_packet = TRUE;
 350         tcp_dissect_pdus(tvb, pinfo, tree, ipdc_desegment, 4,
 351                 get_ipdc_pdu_len, dissect_ipdc_tcp_pdu);
 352 }
 353
 354 void
 355 proto_register_ipdc(void)
 356 {
 357
 358         static hf_register_info hf[] = {
 359                 { &hf_ipdc_nr,
 360                         { "N(r)",       "ipdc.nr",
 361                         FT_UINT8, BASE_DEC, NULL, 0x0,
 362                         "Receive sequence number", HFILL }
 363                 },
 364
 365                 { &hf_ipdc_ns,
 366                         { "N(s)",       "ipdc.ns",
 367                         FT_UINT8, BASE_DEC, NULL, 0x0,
 368                         "Transmit sequence number", HFILL }
 369                 },
 370
 371                 { &hf_ipdc_payload_len,
 372                         { "Payload length",     "ipdc.length",
 373                         FT_UINT16, BASE_DEC, NULL, 0x0,
 374                         "Payload length", HFILL }
 375                 },
 376
 377                 { &hf_ipdc_protocol_id,
 378                         { "Protocol ID",        "ipdc.protocol_id",
 379                         FT_UINT8, BASE_HEX, NULL, 0x0,
 380                         "Protocol ID", HFILL }
 381                 },
 382
 383                 { &hf_ipdc_trans_id_size,
 384                         { "Transaction ID size",        "ipdc.trans_id_size",
 385                         FT_UINT8, BASE_DEC, NULL, 0x0,
 386                         "Transaction ID size", HFILL }
 387                 },
 388
 389                 { &hf_ipdc_trans_id,
 390                         { "Transaction ID",     "ipdc.trans_id",
 391                         FT_BYTES, BASE_HEX, NULL, 0x0,
 392                         "Transaction ID", HFILL }
 393                 },
 394
 395                 { &hf_ipdc_message_code,
 396                         { "Message code",       "ipdc.message_code",
 397                         FT_UINT16, BASE_HEX, VALS(message_code_vals), 0x0,
 398                         "Message Code", HFILL }
 399                 },
 400         };
 401
 402         static gint *ett[] = {
 403                 &ett_ipdc,
 404                 &ett_ipdc_tag,
 405         };
 406
 407         module_t *ipdc_module;
 408
 409         proto_ipdc = proto_register_protocol("IP Device Control (SS7 over IP)",
 410             "IPDC", "ipdc");
 411         proto_register_field_array(proto_ipdc, hf, array_length(hf));
 412         proto_register_subtree_array(ett, array_length(ett));
 413
 414         ipdc_module = prefs_register_protocol(proto_ipdc, proto_reg_handoff_ipdc);
 415         prefs_register_bool_preference(ipdc_module, "desegment_ipdc_messages",
 416                 "Reassemble IPDC messages spanning multiple TCP segments",
 417                 "Whether the IPDC dissector should reassemble messages spanning multiple TCP segments."
 418                 " To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
 419                 &ipdc_desegment);
 420         prefs_register_uint_preference(ipdc_module, "tcp.port",
 421                 "IPDC monitoring port",
 422                 "Set the IPDC monitoring port", 10,
 423                 &ipdc_port_pref);
 424 }
 425
 426 void
 427 proto_reg_handoff_ipdc(void)
 428 {
 429         static gint last_ipdc_port_pref = 0;
 430         static dissector_handle_t ipdc_tcp_handle = NULL;
 431
 432         if (ipdc_tcp_handle) {
 433                 dissector_delete("tcp.port", last_ipdc_port_pref,
 434                         ipdc_tcp_handle);
 435         } else {
 436                 ipdc_tcp_handle =
 437                         create_dissector_handle(dissect_ipdc_tcp, proto_ipdc);
 438                 q931_handle = find_dissector("q931");
 439         }
 440
 441         last_ipdc_port_pref = ipdc_port_pref;
 442         dissector_add("tcp.port", ipdc_port_pref, ipdc_tcp_handle);
 443 }