epan/dissectors/packet-esis.c

   1 /* packet-esis.c
   2  * Routines for ISO/OSI End System to Intermediate System
   3  * Routing Exchange Protocol ISO 9542.
   4  *
   5  * Ralf Schneider <Ralf.Schneider@t-online.de>
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * SPDX-License-Identifier: GPL-2.0-or-later
  12  */
  13
  14 #include "config.h"
  15
  16 #include <epan/packet.h>
  17 #include <epan/expert.h>
  18 #include <epan/nlpid.h>
  19 #include <epan/unit_strings.h>
  20 #include "packet-osi.h"
  21 #include "packet-osi-options.h"
  22
  23 /* The version we support is 1 */
  24 #define ESIS_REQUIRED_VERSION    1
  25
  26 /* ESIS PDU types */
  27 #define ESIS_ESH_PDU    02
  28 #define ESIS_ISH_PDU    04
  29 #define ESIS_RD_PDU     06
  30
  31 /* The length of the fixed part */
  32 #define ESIS_HDR_FIXED_LENGTH 9
  33
  34 void proto_register_esis(void);
  35 void proto_reg_handoff_esis(void);
  36
  37 /* esis base header */
  38 static int  proto_esis;
  39
  40 static int  hf_esis_nlpi;
  41 static int  hf_esis_length;
  42 static int  hf_esis_version;
  43 static int  hf_esis_reserved;
  44 static int  hf_esis_type;
  45 static int  hf_esis_holdtime;
  46 static int  hf_esis_checksum;
  47 static int  hf_esis_checksum_status;
  48 /* Generated from convert_proto_tree_add_text.pl */
  49 static int hf_esis_dal;
  50 static int hf_esis_number_of_source_addresses;
  51 static int hf_esis_netl;
  52 static int hf_esis_sal;
  53 static int hf_esis_sa;
  54 static int hf_esis_bsnpal;
  55 static int hf_esis_net;
  56 static int hf_esis_da;
  57 static int hf_esis_bsnpa;
  58
  59 static int ett_esis;
  60 static int ett_esis_area_addr;
  61 static int ett_esis_network;
  62 static int ett_esis_dest_addr;
  63 static int ett_esis_subnetwork;
  64
  65
  66 static expert_field ei_esis_version;
  67 static expert_field ei_esis_length;
  68 static expert_field ei_esis_type;
  69 static expert_field ei_esis_checksum;
  70
  71 static dissector_handle_t esis_handle;
  72
  73 static const value_string esis_vals[] = {
  74   { ESIS_ESH_PDU, "ES HELLO"},
  75   { ESIS_ISH_PDU, "IS HELLO"},
  76   { ESIS_RD_PDU,  "RD REQUEST"},
  77   { 0,             NULL} };
  78
  79 /* ################## Descriptions ###########################################*/
  80 /* Parameters for the ESH PDU
  81  * Source Address Parameter:
  82  *
  83  * Octet:    Length:   Parameter Type:
  84  *     10          1   Number of Source Addresses ( NSAPs served by this Network
  85  *     11          1   Source Address Length Indicator ( SAL )     #    Entity )
  86  * 12-m-1   variable   Source Address ( NSAP )
  87  *      m              Options, dissected in osi.c
  88  *
  89  *
  90  * Parameter for the ISH PDU:
  91  * Network Entity Title Parameter:
  92  *
  93  * Octet:    Length:   Parameter Type:
  94  *     10          1   Network Entity Title Length Indicator ( NETL )
  95  * 11-m-1   variable   Network Entity Title ( NET )
  96  *      m              Options, dissected in osi.c
  97  *
  98  *
  99  * Parameter for the RD PDU:
 100  * When re-directed to an IS:
 101  *
 102  *  Octet:   Length:   Parameter Type:
 103  *      10         1   Destination Address Length Indicator ( DAL )
 104  *  11>m-1  variable   Destination Address ( DA )
 105  *       m         1   Subnetwork Address Length Indicator ( BSNPAL )
 106  * m+1>n-1  variable   Subnetwork Address ( BSNPA )
 107  *       n         1   Network Entity Title Length Indicator ( NETL )
 108  * n+1>p-1  variable   Network Entity Title ( NET )
 109  *       p             Options, dissected in osi.c
 110  *
 111  *
 112  * Parameter for the RD PDU:
 113  * When re-directed to an ES:
 114  *
 115  *  Octet:   Length:   Parameter Type:
 116  *      10         1   Destination Address Length Indicator ( DAL )
 117  *  11>m-1  variable   Destination Address ( DA )
 118  *       m         1   Subnetwork Address Length Indicator ( BSNPAL )
 119  * m+1>n-1  variable   Subnetwork Address ( BSNPA )
 120  *       n         1   Network Entity Title Length Indicator ( NETL ) == 0
 121  *     n+1             Options, dissected in osi.c
 122  *
 123  */
 124
 125 /* ############################ Tool Functions ############################## */
 126
 127
 128 static void
 129 esis_dissect_esh_pdu( uint8_t len, tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo) {
 130     proto_tree *esis_area_tree;
 131     int         offset  = 0;
 132     unsigned    no_sa, sal;
 133
 134     proto_item  *ti;
 135
 136     offset += ESIS_HDR_FIXED_LENGTH;
 137
 138     ti = proto_tree_add_item_ret_uint( tree, hf_esis_number_of_source_addresses, tvb, offset, 1, ENC_NA, &no_sa);
 139     len--;
 140     offset++;
 141
 142     esis_area_tree = proto_item_add_subtree( ti, ett_esis_area_addr );
 143     while ( no_sa-- > 0 ) {
 144       proto_tree_add_item_ret_uint(esis_area_tree, hf_esis_sal, tvb, offset, 1, ENC_NA, &sal);
 145       offset++;
 146       proto_tree_add_string(esis_area_tree, hf_esis_sa, tvb, offset, sal, print_nsap_net( pinfo->pool, tvb, offset, sal ) );
 147       offset += sal;
 148       len    -= ( sal + 1 );
 149     }
 150     dissect_osi_options( len, tvb, offset, tree, pinfo );
 151
 152 } /* esis_dissect_esh_pdu */
 153
 154 static void
 155 esis_dissect_ish_pdu( uint8_t len, tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo) {
 156
 157     int   offset  = 0;
 158     int   netl    = 0;
 159     proto_tree* network_tree;
 160
 161     offset += ESIS_HDR_FIXED_LENGTH;
 162
 163     netl = (int) tvb_get_uint8(tvb, offset);
 164     network_tree = proto_tree_add_subtree( tree, tvb, offset, netl + 1, ett_esis_network, NULL,
 165                          "### Network Entity Title Section ###");
 166     proto_tree_add_uint(network_tree, hf_esis_netl, tvb, offset++, 1, netl);
 167     proto_tree_add_string(network_tree, hf_esis_net, tvb, offset, netl, print_nsap_net( pinfo->pool, tvb, offset, netl ) );
 168     offset += netl;
 169     len    -= ( netl + 1 );
 170
 171     dissect_osi_options( len, tvb, offset, network_tree, pinfo );
 172 }
 173
 174 static void
 175 esis_dissect_redirect_pdu( uint8_t len, tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo) {
 176
 177     int   offset  = 0;
 178     int   tmpl    = 0;
 179     proto_tree *dest_tree, *subnet_tree, *network_tree;
 180
 181     offset += ESIS_HDR_FIXED_LENGTH;
 182
 183     tmpl = (int) tvb_get_uint8(tvb, offset);
 184     dest_tree = proto_tree_add_subtree( tree, tvb, offset, tmpl + 1, ett_esis_dest_addr, NULL,
 185                          "### Destination Address Section ###" );
 186     proto_tree_add_uint(dest_tree, hf_esis_dal, tvb, offset++, 1, tmpl);
 187     proto_tree_add_string( dest_tree, hf_esis_da, tvb, offset, tmpl,
 188                          print_nsap_net( pinfo->pool, tvb, offset, tmpl ) );
 189     offset += tmpl;
 190     len    -= ( tmpl + 1 );
 191     tmpl    = (int) tvb_get_uint8(tvb, offset);
 192
 193     subnet_tree = proto_tree_add_subtree( tree, tvb, offset, tmpl + 1, ett_esis_subnetwork, NULL,
 194                          "###  Subnetwork Address Section ###");
 195     proto_tree_add_uint(subnet_tree, hf_esis_bsnpal, tvb, offset++, 1, tmpl);
 196     proto_tree_add_item(subnet_tree, hf_esis_bsnpa, tvb, offset, tmpl, ENC_NA);
 197     offset += tmpl;
 198     len    -= ( tmpl + 1 );
 199     tmpl    = (int) tvb_get_uint8(tvb, offset);
 200
 201     if ( 0 == tmpl ) {
 202       network_tree = proto_tree_add_subtree( tree, tvb, offset, 1, ett_esis_network, NULL,
 203                            "### No Network Entity Title Section ###" );
 204       offset++;
 205       len--;
 206     }
 207     else {
 208       network_tree = proto_tree_add_subtree( tree, tvb, offset, 1, ett_esis_network, NULL,
 209                            "### Network Entity Title Section ###" );
 210       proto_tree_add_uint(network_tree, hf_esis_netl, tvb, offset++, 1, tmpl);
 211       proto_tree_add_string( network_tree, hf_esis_net, tvb, offset, tmpl,
 212                            print_nsap_net( pinfo->pool, tvb, offset, tmpl ) );
 213       offset += tmpl;
 214       len    -= ( tmpl + 1 );
 215     }
 216     dissect_osi_options( len, tvb, offset, network_tree, pinfo );
 217 }
 218
 219
 220 /*
 221  * Name: dissect_esis()
 222  *
 223  * Description:
 224  *   Main entry area for esis de-mangling.  This will build the
 225  *   main esis tree data and call the sub-protocols as needed.
 226  *
 227  * Input:
 228  *   tvbuff *      : tvbuff referring to packet data
 229  *   packet_info * : info for current packet
 230  *   proto_tree *  : tree of display data.  May be NULL.
 231  *
 232  * Output:
 233  *   void, but we will add to the proto_tree if it is not NULL.
 234  */
 235 static int
 236 dissect_esis(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) {
 237   uint8_t version, length;
 238   proto_item *ti, *type_item;
 239   proto_tree *esis_tree    = NULL;
 240   uint8_t     variable_len, type;
 241   uint16_t    checksum;
 242
 243   col_set_str(pinfo->cinfo, COL_PROTOCOL, "ESIS");
 244   col_clear(pinfo->cinfo, COL_INFO);
 245
 246     ti = proto_tree_add_item(tree, proto_esis, tvb, 0, -1, ENC_NA);
 247     esis_tree = proto_item_add_subtree(ti, ett_esis);
 248
 249     proto_tree_add_item( esis_tree, hf_esis_nlpi, tvb, 0, 1, ENC_BIG_ENDIAN);
 250     ti = proto_tree_add_item( esis_tree, hf_esis_length, tvb, 1, 1, ENC_BIG_ENDIAN );
 251     length = tvb_get_uint8(tvb, 1);
 252     if (length < ESIS_HDR_FIXED_LENGTH) {
 253       expert_add_info_format(pinfo, ti, &ei_esis_length,
 254                            "Bogus ESIS length (%u, must be >= %u)",
 255                            length, ESIS_HDR_FIXED_LENGTH );
 256     }
 257
 258     version = tvb_get_uint8(tvb, 2);
 259     ti = proto_tree_add_item( esis_tree, hf_esis_version, tvb, 2, 1, ENC_BIG_ENDIAN);
 260     if (version != ESIS_REQUIRED_VERSION){
 261       expert_add_info_format(pinfo, ti, &ei_esis_version,
 262                            "Unknown ESIS version (%u vs %u)",
 263                            version, ESIS_REQUIRED_VERSION );
 264     }
 265
 266     proto_tree_add_item( esis_tree, hf_esis_reserved, tvb, 3, 1, ENC_BIG_ENDIAN);
 267
 268     type_item = proto_tree_add_item( esis_tree, hf_esis_type, tvb, 4, 1, ENC_BIG_ENDIAN);
 269     type = tvb_get_uint8(tvb, 4) & OSI_PDU_TYPE_MASK;
 270
 271     proto_tree_add_item(esis_tree, hf_esis_holdtime, tvb, 5, 2, ENC_BIG_ENDIAN);
 272
 273     checksum = tvb_get_ntohs(tvb, 7);
 274     if (checksum == 0) {
 275         /* No checksum present */
 276         proto_tree_add_checksum(esis_tree, tvb, 7, hf_esis_checksum, -1, NULL, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NOT_PRESENT);
 277     } else {
 278         uint32_t c0 = 0, c1 = 0;
 279
 280         if (osi_calc_checksum(tvb, 0, length, &c0, &c1)) {
 281             /* Successfully processed checksum, verify it */
 282             proto_tree_add_checksum(esis_tree, tvb, 7, hf_esis_checksum, hf_esis_checksum_status, &ei_esis_checksum, pinfo, c0 | c1, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY|PROTO_CHECKSUM_ZERO);
 283         } else {
 284             proto_tree_add_checksum(esis_tree, tvb, 7, hf_esis_checksum, hf_esis_checksum_status, &ei_esis_checksum, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);
 285         }
 286     }
 287
 288   /*
 289    * Let us make sure we use the same names for all our decodes
 290    * here.  First, dump the name into info column, and THEN
 291    * dispatch the sub-type.
 292    */
 293   col_add_str(pinfo->cinfo, COL_INFO,
 294                 val_to_str( type, esis_vals,
 295                             "Unknown (0x%x)" ) );
 296
 297   variable_len = length - ESIS_HDR_FIXED_LENGTH;
 298
 299   switch (type) {
 300   case ESIS_ESH_PDU:
 301     esis_dissect_esh_pdu( variable_len, tvb, esis_tree, pinfo);
 302     break;
 303   case ESIS_ISH_PDU:
 304     esis_dissect_ish_pdu( variable_len, tvb, esis_tree, pinfo);
 305     break;
 306   case ESIS_RD_PDU:
 307     esis_dissect_redirect_pdu( variable_len, tvb, esis_tree, pinfo);
 308     break;
 309   default:
 310     expert_add_info(pinfo, type_item, &ei_esis_type);
 311   }
 312   return tvb_captured_length(tvb);
 313 } /* dissect_esis */
 314
 315
 316 /*
 317  * Name: proto_register_esis()
 318  *
 319  * Description:
 320  *      main register for esis protocol set.  We register some display
 321  *      formats and the protocol module variables.
 322  *
 323  *      NOTE: this procedure to autolinked by the makefile process that
 324  *      builds register.c
 325  *
 326  * Input:
 327  *      void
 328  *
 329  * Output:
 330  *      void
 331  */
 332 void
 333 proto_register_esis(void) {
 334   static hf_register_info hf[] = {
 335     { &hf_esis_nlpi,
 336       { "Network Layer Protocol Identifier", "esis.nlpi",
 337         FT_UINT8, BASE_HEX, VALS(nlpid_vals), 0x0, NULL, HFILL }},
 338
 339     { &hf_esis_length,
 340       { "PDU Length", "esis.length",  FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
 341
 342     { &hf_esis_version,
 343       { "Version", "esis.ver",  FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
 344
 345     { &hf_esis_reserved,
 346       { "Reserved(==0)", "esis.res",  FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
 347
 348     { &hf_esis_type,
 349       { "PDU Type", "esis.type",      FT_UINT8, BASE_DEC, VALS(esis_vals), OSI_PDU_TYPE_MASK, NULL, HFILL }},
 350
 351     { &hf_esis_holdtime,
 352       { "Holding Time", "esis.htime", FT_UINT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_second_seconds), 0x0, NULL, HFILL }},
 353
 354     { &hf_esis_checksum,
 355       { "Checksum", "esis.chksum",    FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }},
 356
 357     { &hf_esis_checksum_status,
 358       { "Checksum Status", "esis.chksum.status",    FT_UINT8, BASE_NONE, VALS(proto_checksum_vals), 0x0, NULL, HFILL }},
 359
 360       /* Generated from convert_proto_tree_add_text.pl */
 361       { &hf_esis_number_of_source_addresses, { "Number of Source Addresses (SA, Format: NSAP)", "esis.number_of_source_addresses", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
 362       { &hf_esis_sal, { "SAL", "esis.sal", FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_octet_octets), 0x0, NULL, HFILL }},
 363       { &hf_esis_sa, { "SA", "esis.sa", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 364       { &hf_esis_netl, { "NETL", "esis.netl", FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_octet_octets), 0x0, NULL, HFILL }},
 365       { &hf_esis_dal, { "DAL", "esis.dal", FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_octet_octets), 0x0, NULL, HFILL }},
 366       { &hf_esis_bsnpal, { "BSNPAL", "esis.bsnpal", FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_octet_octets), 0x0, NULL, HFILL }},
 367       { &hf_esis_net, { "NET", "esis.net", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 368       { &hf_esis_da, { "DA", "esis.da", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 369       { &hf_esis_bsnpa, { "BSNPA", "esis.bsnpa", FT_SYSTEM_ID, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 370   };
 371
 372   static int *ett[] = {
 373     &ett_esis,
 374     &ett_esis_area_addr,
 375     &ett_esis_network,
 376     &ett_esis_dest_addr,
 377     &ett_esis_subnetwork
 378   };
 379
 380   static ei_register_info ei[] = {
 381     { &ei_esis_version, { "esis.ver.unknown", PI_PROTOCOL, PI_WARN, "Unknown ESIS version", EXPFILL }},
 382     { &ei_esis_length, { "esis.length.invalid", PI_MALFORMED, PI_ERROR, "Bogus ESIS length", EXPFILL }},
 383     { &ei_esis_type, { "esis.type.unknown", PI_PROTOCOL, PI_WARN, "Unknown ESIS packet type", EXPFILL }},
 384     { &ei_esis_checksum, { "esis.bad_checksum", PI_CHECKSUM, PI_ERROR, "Bad checksum", EXPFILL }},
 385   };
 386
 387   expert_module_t* expert_esis;
 388
 389   proto_esis = proto_register_protocol( PROTO_STRING_ESIS, "ESIS", "esis");
 390   proto_register_field_array(proto_esis, hf, array_length(hf));
 391   proto_register_subtree_array(ett, array_length(ett));
 392   expert_esis = expert_register_protocol(proto_esis);
 393   expert_register_field_array(expert_esis, ei, array_length(ei));
 394   esis_handle = register_dissector("esis", dissect_esis, proto_esis);
 395 }
 396
 397 void
 398 proto_reg_handoff_esis(void)
 399 {
 400   dissector_add_uint("osinl.incl", NLPID_ISO9542_ESIS, esis_handle);
 401 }
 402
 403 /*
 404  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 405  *
 406  * Local Variables:
 407  * c-basic-offset: 2
 408  * tab-width: 8
 409  * indent-tabs-mode: nil
 410  * End:
 411  *
 412  * ex: set shiftwidth=2 tabstop=8 expandtab:
 413  * :indentSize=2:tabSize=8:noTabs=true:
 414  */