epan/dissectors/packet-rip.c

   1 /* packet-rip.c
   2  * Routines for RIPv1 and RIPv2 packet disassembly
   3  * RFC1058 (STD 34), RFC1388, RFC1723, RFC2453 (STD 56)
   4  * (c) Copyright Hannes R. Boehm <hannes@boehm.org>
   5  *
   6  * RFC2082 ( Keyed Message Digest Algorithm )
   7  *   Emanuele Caratti  <wiz@iol.it>
   8  *
   9  * $Id$
  10  *
  11  * Wireshark - Network traffic analyzer
  12  * By Gerald Combs <gerald@wireshark.org>
  13  * Copyright 1998 Gerald Combs
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License
  17  * as published by the Free Software Foundation; either version 2
  18  * of the License, or (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  * GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program; if not, write to the Free Software
  27  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  28  */
  29
  30 #define NEW_PROTO_TREE_API
  31
  32 #include "config.h"
  33
  34 #include <glib.h>
  35 #include <epan/packet.h>
  36 #include <epan/emem.h>
  37 #include <epan/prefs.h>
  38
  39 #define UDP_PORT_RIP    520
  40
  41 #define RIPv1   1
  42 #define RIPv2   2
  43
  44 static const value_string version_vals[] = {
  45         { RIPv1, "RIPv1" },
  46         { RIPv2, "RIPv2" },
  47         { 0,     NULL }
  48 };
  49
  50 static const value_string command_vals[] = {
  51         { 1, "Request" },
  52         { 2, "Response" },
  53         { 3, "Traceon" },
  54         { 4, "Traceoff" },
  55         { 5, "Vendor specific (Sun)" },
  56         { 0, NULL }
  57 };
  58
  59 #define AFVAL_UNSPEC    0
  60 #define AFVAL_IP        2
  61
  62 static const value_string family_vals[] = {
  63         { AFVAL_UNSPEC, "Unspecified" },
  64         { AFVAL_IP,     "IP" },
  65         { 0,            NULL }
  66 };
  67
  68 #define AUTH_IP_ROUTE           1
  69 #define AUTH_PASSWORD           2
  70 #define AUTH_KEYED_MSG_DIGEST   3
  71
  72 static const value_string rip_auth_type[] = {
  73         { AUTH_IP_ROUTE,                "IP Route" },
  74         { AUTH_PASSWORD,                "Simple Password" },
  75         { AUTH_KEYED_MSG_DIGEST,        "Keyed Message Digest" },
  76         { 0,                            NULL }
  77 };
  78
  79 #define RIP_HEADER_LENGTH 4
  80 #define RIP_ENTRY_LENGTH 20
  81 #define MD5_AUTH_DATA_LEN 16
  82
  83 static gboolean pref_display_routing_domain = FALSE;
  84
  85 void proto_reg_handoff_rip(void);
  86
  87
  88 static dissector_handle_t rip_handle;
  89
  90 static header_field_info *hfi_rip = NULL;
  91
  92 #define RIP_HFI_INIT HFI_INIT(proto_rip)
  93
  94 static header_field_info hfi_rip_command RIP_HFI_INIT =
  95         { "Command", "rip.command", FT_UINT8, BASE_DEC,
  96           VALS(command_vals), 0, "What type of RIP Command is this", HFILL };
  97
  98 static header_field_info hfi_rip_version RIP_HFI_INIT =
  99         { "Version", "rip.version", FT_UINT8, BASE_DEC,
 100           VALS(version_vals), 0, "Version of the RIP protocol", HFILL };
 101
 102 static header_field_info hfi_rip_routing_domain RIP_HFI_INIT =
 103         { "Routing Domain", "rip.routing_domain", FT_UINT16, BASE_DEC,
 104           NULL, 0, "RIPv2 Routing Domain", HFILL };
 105
 106 static header_field_info hfi_rip_ip RIP_HFI_INIT =
 107         { "IP Address", "rip.ip", FT_IPv4, BASE_NONE,
 108           NULL, 0, NULL, HFILL};
 109
 110 static header_field_info hfi_rip_netmask RIP_HFI_INIT =
 111         { "Netmask", "rip.netmask", FT_IPv4, BASE_NONE,
 112           NULL, 0, NULL, HFILL};
 113
 114 static header_field_info hfi_rip_next_hop RIP_HFI_INIT =
 115         { "Next Hop", "rip.next_hop", FT_IPv4, BASE_NONE,
 116           NULL, 0, "Next Hop router for this route", HFILL};
 117
 118 static header_field_info hfi_rip_metric RIP_HFI_INIT =
 119         { "Metric", "rip.metric", FT_UINT16, BASE_DEC,
 120           NULL, 0, "Metric for this route", HFILL };
 121
 122 static header_field_info hfi_rip_auth RIP_HFI_INIT =
 123         { "Authentication type", "rip.auth.type", FT_UINT16, BASE_DEC,
 124           VALS(rip_auth_type), 0, "Type of authentication", HFILL };
 125
 126 static header_field_info hfi_rip_auth_passwd RIP_HFI_INIT =
 127         { "Password", "rip.auth.passwd", FT_STRING, BASE_NONE,
 128           NULL, 0, "Authentication password", HFILL };
 129
 130 static header_field_info hfi_rip_family RIP_HFI_INIT =
 131         { "Address Family", "rip.family", FT_UINT16, BASE_DEC,
 132           VALS(family_vals), 0, NULL, HFILL };
 133
 134 static header_field_info hfi_rip_route_tag RIP_HFI_INIT =
 135         { "Route Tag", "rip.route_tag", FT_UINT16, BASE_DEC,
 136           NULL, 0, NULL, HFILL };
 137
 138 static gint ett_rip = -1;
 139 static gint ett_rip_vec = -1;
 140 static gint ett_auth_vec = -1;
 141
 142 static void dissect_unspec_rip_vektor(tvbuff_t *tvb, int offset, guint8 version,
 143     proto_tree *tree);
 144 static void dissect_ip_rip_vektor(tvbuff_t *tvb, int offset, guint8 version,
 145     proto_tree *tree);
 146 static gint dissect_rip_authentication(tvbuff_t *tvb, int offset,
 147     proto_tree *tree);
 148
 149 static void
 150 dissect_rip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 151 {
 152     int offset = 0;
 153     proto_tree *rip_tree = NULL;
 154     proto_item *ti;
 155     guint8 command;
 156     guint8 version;
 157     guint16 family;
 158     gint trailer_len = 0;
 159     gboolean is_md5_auth = FALSE;
 160
 161     col_set_str(pinfo->cinfo, COL_PROTOCOL, "RIP");
 162     col_clear(pinfo->cinfo, COL_INFO);
 163
 164     command = tvb_get_guint8(tvb, 0);
 165     version = tvb_get_guint8(tvb, 1);
 166
 167     col_set_str(pinfo->cinfo, COL_PROTOCOL,
 168                     val_to_str_const(version, version_vals, "RIP"));
 169     col_add_str(pinfo->cinfo, COL_INFO,
 170                     val_to_str(command, command_vals, "Unknown command (%u)"));
 171
 172     if (tree) {
 173         ti = proto_tree_add_item(tree, hfi_rip, tvb, 0, -1, ENC_NA);
 174         rip_tree = proto_item_add_subtree(ti, ett_rip);
 175
 176         proto_tree_add_uint(rip_tree, &hfi_rip_command, tvb, 0, 1, command);
 177         proto_tree_add_uint(rip_tree, &hfi_rip_version, tvb, 1, 1, version);
 178         if (version == RIPv2 && pref_display_routing_domain == TRUE)
 179             proto_tree_add_uint(rip_tree, &hfi_rip_routing_domain, tvb, 2, 2,
 180                         tvb_get_ntohs(tvb, 2));
 181
 182         /* skip header */
 183         offset = RIP_HEADER_LENGTH;
 184
 185         /* zero or more entries */
 186         while (tvb_reported_length_remaining(tvb, offset) > trailer_len ) {
 187             family = tvb_get_ntohs(tvb, offset);
 188             switch (family) {
 189             case AFVAL_UNSPEC: /* Unspecified */
 190                 /*
 191                  * There should be one entry in the request, and a metric
 192                  * of infinity, meaning "show the entire routing table".
 193                  */
 194                 dissect_unspec_rip_vektor(tvb, offset, version, rip_tree);
 195                 break;
 196             case AFVAL_IP: /* IP */
 197                 dissect_ip_rip_vektor(tvb, offset, version, rip_tree);
 198                 break;
 199             case 0xFFFF:
 200                 if( offset == RIP_HEADER_LENGTH ) {
 201                         trailer_len=dissect_rip_authentication(tvb, offset, rip_tree);
 202                         is_md5_auth = TRUE;
 203                 break;
 204                 }
 205                 if(is_md5_auth && tvb_reported_length_remaining(tvb, offset) == 20)
 206                         break;
 207                 /* Intentional fall through: auth Entry MUST be the first! */
 208             default:
 209                 proto_tree_add_text(rip_tree, tvb, offset,
 210                                 RIP_ENTRY_LENGTH, "Unknown address family %u",
 211                                 family);
 212                 break;
 213             }
 214
 215             offset += RIP_ENTRY_LENGTH;
 216         }
 217     }
 218 }
 219
 220 static void
 221 dissect_unspec_rip_vektor(tvbuff_t *tvb, int offset, guint8 version,
 222                       proto_tree *tree)
 223 {
 224     proto_item *ti;
 225     proto_tree *rip_vektor_tree;
 226     guint32 metric;
 227
 228     metric = tvb_get_ntohl(tvb, offset+16);
 229     ti = proto_tree_add_text(tree, tvb, offset,
 230                              RIP_ENTRY_LENGTH, "Address not specified, Metric: %u",
 231                              metric);
 232     rip_vektor_tree = proto_item_add_subtree(ti, ett_rip_vec);
 233
 234     proto_tree_add_item(rip_vektor_tree, &hfi_rip_family, tvb, offset, 2, ENC_BIG_ENDIAN);
 235     if (version == RIPv2) {
 236         proto_tree_add_item(rip_vektor_tree, &hfi_rip_route_tag, tvb, offset+2, 2,
 237                         ENC_BIG_ENDIAN);
 238         proto_tree_add_item(rip_vektor_tree, &hfi_rip_netmask, tvb, offset+8, 4,
 239                             ENC_BIG_ENDIAN);
 240         proto_tree_add_item(rip_vektor_tree, &hfi_rip_next_hop, tvb, offset+12, 4,
 241                             ENC_BIG_ENDIAN);
 242     }
 243     proto_tree_add_uint(rip_vektor_tree, &hfi_rip_metric, tvb,
 244                         offset+16, 4, metric);
 245 }
 246
 247 static void
 248 dissect_ip_rip_vektor(tvbuff_t *tvb, int offset, guint8 version,
 249                       proto_tree *tree)
 250 {
 251     proto_item *ti;
 252     proto_tree *rip_vektor_tree;
 253     guint32 metric;
 254
 255     metric = tvb_get_ntohl(tvb, offset+16);
 256     ti = proto_tree_add_text(tree, tvb, offset,
 257                              RIP_ENTRY_LENGTH, "IP Address: %s, Metric: %u",
 258                              tvb_ip_to_str(tvb, offset+4), metric);
 259     rip_vektor_tree = proto_item_add_subtree(ti, ett_rip_vec);
 260
 261     proto_tree_add_item(rip_vektor_tree, &hfi_rip_family, tvb, offset, 2, ENC_BIG_ENDIAN);
 262     if (version == RIPv2) {
 263         proto_tree_add_item(rip_vektor_tree, &hfi_rip_route_tag, tvb, offset+2, 2,
 264                         ENC_BIG_ENDIAN);
 265     }
 266
 267     proto_tree_add_item(rip_vektor_tree, &hfi_rip_ip, tvb, offset+4, 4, ENC_BIG_ENDIAN);
 268
 269     if (version == RIPv2) {
 270         proto_tree_add_item(rip_vektor_tree, &hfi_rip_netmask, tvb, offset+8, 4,
 271                             ENC_BIG_ENDIAN);
 272         proto_tree_add_item(rip_vektor_tree, &hfi_rip_next_hop, tvb, offset+12, 4,
 273                             ENC_BIG_ENDIAN);
 274     }
 275     proto_tree_add_uint(rip_vektor_tree, &hfi_rip_metric, tvb,
 276                         offset+16, 4, metric);
 277 }
 278
 279 static gint
 280 dissect_rip_authentication(tvbuff_t *tvb, int offset, proto_tree *tree)
 281 {
 282     proto_item *ti;
 283     proto_tree *rip_authentication_tree;
 284     guint16 authtype;
 285     guint32 val, digest_off, auth_data_len;
 286
 287     auth_data_len = 0;
 288     authtype = tvb_get_ntohs(tvb, offset + 2);
 289
 290     ti = proto_tree_add_text(tree, tvb, offset, RIP_ENTRY_LENGTH,
 291                         "Authentication: %s", val_to_str( authtype, rip_auth_type, "Unknown (%u)" ) );
 292     rip_authentication_tree = proto_item_add_subtree(ti, ett_rip_vec);
 293
 294     proto_tree_add_uint(rip_authentication_tree, &hfi_rip_auth, tvb, offset+2, 2,
 295                 authtype);
 296
 297     switch ( authtype ) {
 298
 299     case AUTH_PASSWORD: /* Plain text password */
 300         proto_tree_add_item(rip_authentication_tree, &hfi_rip_auth_passwd,
 301                         tvb, offset+4, 16, ENC_ASCII|ENC_NA);
 302         break;
 303
 304     case AUTH_KEYED_MSG_DIGEST: /* Keyed MD5 rfc 2082 */
 305         digest_off = tvb_get_ntohs( tvb, offset+4 );
 306         proto_tree_add_text( rip_authentication_tree, tvb, offset+4, 2,
 307                         "Digest Offset: %u" , digest_off );
 308         val = tvb_get_guint8( tvb, offset+6 );
 309         proto_tree_add_text( rip_authentication_tree, tvb, offset+6, 1,
 310                         "Key ID: %u" , val );
 311         auth_data_len = tvb_get_guint8( tvb, offset+7 );
 312         proto_tree_add_text( rip_authentication_tree, tvb, offset+7, 1,
 313                         "Auth Data Len: %u" , auth_data_len );
 314         val = tvb_get_ntohl( tvb, offset+8 );
 315         proto_tree_add_text( rip_authentication_tree, tvb, offset+8, 4,
 316                         "Seq num: %u" , val );
 317         proto_tree_add_text( rip_authentication_tree, tvb, offset+12, 8,
 318                         "Zero Padding" );
 319         ti = proto_tree_add_text( rip_authentication_tree, tvb, offset-4+digest_off,
 320                         MD5_AUTH_DATA_LEN+4, "Authentication Data Trailer" );
 321         rip_authentication_tree = proto_item_add_subtree(ti, ett_auth_vec );
 322         proto_tree_add_text( rip_authentication_tree, tvb, offset-4+digest_off+4,
 323                         MD5_AUTH_DATA_LEN, "Authentication Data: %s",
 324                         tvb_bytes_to_str_punct(tvb, offset-4+digest_off+4,
 325                                                MD5_AUTH_DATA_LEN, ' '));
 326         break;
 327     }
 328     return auth_data_len;
 329 }
 330
 331 void
 332 proto_register_rip(void)
 333 {
 334 #ifndef HAVE_HFI_SECTION_INIT
 335         static header_field_info *hfi[] = {
 336                 &hfi_rip_command,
 337                 &hfi_rip_version,
 338                 &hfi_rip_family,
 339                 &hfi_rip_routing_domain,
 340                 &hfi_rip_ip,
 341                 &hfi_rip_netmask,
 342                 &hfi_rip_next_hop,
 343                 &hfi_rip_metric,
 344                 &hfi_rip_auth,
 345                 &hfi_rip_auth_passwd,
 346                 &hfi_rip_route_tag,
 347         };
 348 #endif /* HAVE_HFI_SECTION_INIT */
 349
 350         static gint *ett[] = {
 351                 &ett_rip,
 352                 &ett_rip_vec,
 353                 &ett_auth_vec,
 354         };
 355
 356         module_t *rip_module;
 357         int proto_rip;
 358
 359         proto_rip = proto_register_protocol("Routing Information Protocol",
 360                                 "RIP", "rip");
 361         hfi_rip = proto_registrar_get_nth(proto_rip);
 362
 363         proto_register_fields(proto_rip, hfi, array_length(hfi));
 364         proto_register_subtree_array(ett, array_length(ett));
 365
 366         rip_module = prefs_register_protocol(proto_rip, proto_reg_handoff_rip);
 367
 368         prefs_register_bool_preference(rip_module, "display_routing_domain", "Display Routing Domain field", "Display the third and forth bytes of the RIPv2 header as the Routing Domain field (introduced in RFC 1388 [January 1993] and obsolete as of RFC 1723 [November 1994])", &pref_display_routing_domain);
 369
 370         rip_handle = create_dissector_handle(dissect_rip, proto_rip);
 371 }
 372
 373 void
 374 proto_reg_handoff_rip(void)
 375 {
 376         dissector_add_uint("udp.port", UDP_PORT_RIP, rip_handle);
 377 }