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  * $Id: packet-ipdc.c,v 1.4 2004/03/21 19:57:14 jmayer Exp $
   7  *
   8  * Ethereal - Network traffic analyzer
   9  * By Gerald Combs <gerald@ethereal.com>
  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 <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34
  35 #include <glib.h>
  36 #include <math.h>
  37
  38 #ifdef NEED_SNPRINTF_H
  39 # include "snprintf.h"
  40 #endif
  41
  42 #include <epan/packet.h>
  43 #include "packet-ipdc.h"
  44 #include "packet-tcp.h"
  45 #include <epan/packet.h>
  46 #include "ipproto.h"
  47 #include "prefs.h"
  48
  49 static int proto_ipdc = -1;
  50 static int hf_ipdc_nr = -1;
  51 static int hf_ipdc_ns = -1;
  52 static int hf_ipdc_payload_len = -1;
  53 static int hf_ipdc_protocol_id = -1;
  54 static int hf_ipdc_trans_id_size = -1;
  55 static int hf_ipdc_trans_id = -1;
  56 static int hf_ipdc_message_code = -1;
  57
  58 static gint ett_ipdc = -1;
  59 static gint ett_ipdc_tag = -1;
  60
  61 static gboolean ipdc_desegment = TRUE;
  62 static gint ipdc_port_pref = TCP_PORT_IPDC;
  63
  64 static dissector_handle_t q931_handle;
  65
  66 void proto_reg_handoff_ipdc(void);
  67
  68
  69 static guint
  70 get_ipdc_pdu_len(tvbuff_t *tvb, int offset)
  71 {
  72         return tvb_get_ntohs(tvb,offset+2)+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         char *des;
  85         char *enum_val;
  86         char *tmp_str;
  87         char tmp_tag_text[255+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         guint16 payload_len = (guint16) get_ipdc_pdu_len(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         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 108                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "IPDC");
 109
 110         /* short frame... */
 111         if (payload_len < 4)
 112                 return;
 113
 114         /* clear info column and display send/receive sequence numbers */
 115         if (check_col(pinfo->cinfo, COL_INFO)) {
 116                 col_set_str(pinfo->cinfo, COL_INFO, "");
 117                 col_append_fstr(pinfo->cinfo, COL_INFO, "N(r)=%u N(s)=%u ",
 118                 nr, ns);
 119         }
 120
 121         if (payload_len == 4) {
 122                 if (!tree)
 123                         return;
 124
 125                 ti = proto_tree_add_item(tree, proto_ipdc, tvb, 0, -1, FALSE);
 126                 ipdc_tree = proto_item_add_subtree(ti, ett_ipdc);
 127                 proto_tree_add_item(ipdc_tree, hf_ipdc_nr, tvb, 0, 1, nr);
 128                 proto_tree_add_item(ipdc_tree, hf_ipdc_ns, tvb, 1, 1, ns);
 129                 proto_tree_add_uint(ipdc_tree, hf_ipdc_payload_len, tvb, 2, 2,
 130                         payload_len);
 131
 132                 return;
 133         }
 134
 135         /* IPDC tags present - display message code and trans. ID */
 136         protocol_id = tvb_get_guint8(tvb,4);
 137         trans_id_size = TRANS_ID_SIZE_IPDC;
 138         trans_id = tvb_get_ntohl(tvb,6);
 139         message_code = tvb_get_ntohs(tvb,6+trans_id_size);
 140         offset = 6 + trans_id_size + 2; /* past message_code */
 141
 142         if (check_col(pinfo->cinfo, COL_INFO))
 143                 col_append_fstr(pinfo->cinfo, COL_INFO,
 144                         "TransID=%x %s ",
 145                         trans_id,
 146                         val_to_str(message_code, message_code_vals,
 147                         TEXT_UNDEFINED));
 148
 149         if (!tree)
 150                 return;
 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                                 tmp_str = tvb_memdup(tvb, offset + 2, len);
 205                                 strncpy(tmp_tag_text, tmp_str, len);
 206                                 tmp_tag_text[len] = 0;
 207                                 free(tmp_str);
 208                                 proto_tree_add_text(tag_tree, tvb, offset,
 209                                 len + 2, "0x%2.2x: %s: %s", tag, des,
 210                                 tmp_tag_text);
 211                         break;
 212
 213                         /* unsigned integers, or bytes */
 214                         case IPDC_UINT:
 215                         case IPDC_BYTE:
 216                                 for (i = 0; i < len; i++)
 217                                         tmp_tag += tvb_get_guint8(tvb,
 218                                                 offset + 2 + i) * (guint32)
 219                                                         pow(256, len - (i + 1));
 220
 221                                 if (len == 1)
 222                                         enum_val =
 223                                                 val_to_str( IPDC_TAG(tag) +
 224                                                 tmp_tag,
 225                                                 tag_enum_type, TEXT_UNDEFINED);
 226
 227                                 if (len == 1 &&
 228                                         strcmp(enum_val, TEXT_UNDEFINED) != 0) {
 229                                         proto_tree_add_text(tag_tree, tvb,
 230                                                 offset, len + 2,
 231                                                 "0x%2.2x: %s: %s",
 232                                                 tag, des, enum_val);
 233                                 } else {
 234                                         proto_tree_add_text(tag_tree, tvb,
 235                                                 offset, len + 2,
 236                                                 "0x%2.2x: %s: %u",
 237                                                 tag, des, tmp_tag);
 238                                 }
 239                         break;
 240
 241                         /* IP addresses */
 242                         case IPDC_IPA:
 243                                 if (len == 4) {
 244                                         sprintf(tmp_tag_text, "%u.%u.%u.%u",
 245                                         tvb_get_guint8(tvb, offset + 2),
 246                                         tvb_get_guint8(tvb, offset + 3),
 247                                         tvb_get_guint8(tvb, offset + 4),
 248                                         tvb_get_guint8(tvb, offset + 5));
 249                                 } else if (len == 6) {
 250                                         sprintf(tmp_tag_text, "%u.%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                                         tvb_get_ntohs(tvb, offset + 6));
 256                                 } else {
 257                                         sprintf(tmp_tag_text,
 258                                         "Invalid IP address length %u", len);
 259                                 }
 260
 261                                 proto_tree_add_text(tag_tree, tvb,
 262                                         offset, len + 2,
 263                                         "0x%2.2x: %s: %s",
 264                                         tag, des, tmp_tag_text);
 265                         break;
 266
 267                         /* Line status arrays */
 268                         case IPDC_LINESTATUS:
 269                         case IPDC_CHANNELSTATUS:
 270                                 proto_tree_add_text(tag_tree, tvb, offset,
 271                                 len + 2, "0x%2.2x: %s", tag, des);
 272                                 val_ptr = (type == IPDC_LINESTATUS) ?
 273                                         line_status_vals : channel_status_vals;
 274
 275                                 for (i = 0; i < len; i++) {
 276                                         status = tvb_get_guint8(tvb,offset+2+i);
 277
 278                                         proto_tree_add_text(tag_tree, tvb,
 279                                                 offset + 2 + i, 1,
 280                                                 " %.2u: %.2x (%s)",
 281                                                 i + 1, status,
 282                                                 val_to_str(status,
 283                                                 val_ptr,
 284                                                 TEXT_UNDEFINED));
 285                                 }
 286                         break;
 287
 288                         case IPDC_Q931:
 289                                 q931_tvb =
 290                                         tvb_new_subset(tvb, offset+2, len, len);
 291                                 call_dissector(q931_handle,q931_tvb,pinfo,tree);
 292                         break;
 293
 294                         /* default */
 295                         default:
 296                                 proto_tree_add_text(tag_tree, tvb, offset,
 297                                 len + 2, "0x%2.2x: %s", tag, des);
 298                         break;
 299                 } /* switch */
 300
 301                 offset += len + 2;
 302         }
 303 }
 304
 305 static void
 306 dissect_ipdc_tcp_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 307 {
 308         dissect_ipdc_common(tvb, pinfo, tree);
 309 }
 310
 311 static void
 312 dissect_ipdc_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 313 {
 314         tcp_dissect_pdus(tvb, pinfo, tree, ipdc_desegment, 4,
 315                 get_ipdc_pdu_len, dissect_ipdc_tcp_pdu);
 316 }
 317
 318 void
 319 proto_register_ipdc(void)
 320 {
 321
 322         static hf_register_info hf[] = {
 323                 { &hf_ipdc_nr,
 324                         { "N(r)",       "ipdc.nr",
 325                         FT_UINT8, BASE_DEC, NULL, 0x0,
 326                         "Receive sequence number", HFILL }
 327                 },
 328
 329                 { &hf_ipdc_ns,
 330                         { "N(s)",       "ipdc.ns",
 331                         FT_UINT8, BASE_DEC, NULL, 0x0,
 332                         "Transmit sequence number", HFILL }
 333                 },
 334
 335                 { &hf_ipdc_payload_len,
 336                         { "Payload length",     "ipdc.length",
 337                         FT_UINT16, BASE_DEC, NULL, 0x0,
 338                         "Payload length", HFILL }
 339                 },
 340
 341                 { &hf_ipdc_protocol_id,
 342                         { "Protocol ID",        "ipdc.protocol_id",
 343                         FT_UINT8, BASE_HEX, NULL, 0x0,
 344                         "Protocol ID", HFILL }
 345                 },
 346
 347                 { &hf_ipdc_trans_id_size,
 348                         { "Transaction ID size",        "ipdc.trans_id_size",
 349                         FT_UINT8, BASE_DEC, NULL, 0x0,
 350                         "Transaction ID size", HFILL }
 351                 },
 352
 353                 { &hf_ipdc_trans_id,
 354                         { "Transaction ID",     "ipdc.trans_id",
 355                         FT_BYTES, BASE_HEX, NULL, 0x0,
 356                         "Transaction ID", HFILL }
 357                 },
 358
 359                 { &hf_ipdc_message_code,
 360                         { "Message code",       "ipdc.message_code",
 361                         FT_UINT16, BASE_HEX, VALS(message_code_vals), 0x0,
 362                         "Message Code", HFILL }
 363                 },
 364         };
 365
 366         static gint *ett[] = {
 367                 &ett_ipdc,
 368                 &ett_ipdc_tag,
 369         };
 370
 371         module_t *ipdc_module;
 372
 373         proto_ipdc = proto_register_protocol("IP Device Control (SS7 over IP)",
 374             "IPDC", "ipdc");
 375         proto_register_field_array(proto_ipdc, hf, array_length(hf));
 376         proto_register_subtree_array(ett, array_length(ett));
 377
 378         ipdc_module = prefs_register_protocol(proto_ipdc, proto_reg_handoff_ipdc);
 379         prefs_register_bool_preference(ipdc_module, "desegment_ipdc_messages",
 380                 "Desegment all IPDC messages spanning multiple TCP segments",
 381                 "Whether the IPDC dissector should desegment all messages spanning multiple TCP segments",
 382                 &ipdc_desegment);
 383         prefs_register_uint_preference(ipdc_module, "tcp.port",
 384                 "IPDC monitoring port",
 385                 "Set the IPDC monitoring port", 10,
 386                 &ipdc_port_pref);
 387 }
 388
 389 void
 390 proto_reg_handoff_ipdc(void)
 391 {
 392         static gint last_ipdc_port_pref = 0;
 393         static dissector_handle_t ipdc_tcp_handle = NULL;
 394
 395         if (ipdc_tcp_handle) {
 396                 dissector_delete("tcp.port", last_ipdc_port_pref,
 397                         ipdc_tcp_handle);
 398         } else {
 399                 ipdc_tcp_handle =
 400                         create_dissector_handle(dissect_ipdc_tcp, proto_ipdc);
 401                 q931_handle = find_dissector("q931");
 402         }
 403
 404         last_ipdc_port_pref = ipdc_port_pref;
 405         dissector_add("tcp.port", ipdc_port_pref, ipdc_tcp_handle);
 406 }