The Tcpdump Group git mirrors - tcpdump/blob - print-rip.c

   1 /*
   2  * Copyright (c) 1989, 1990, 1991, 1993, 1994, 1996
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  */
  21
  22 /* \summary: Routing Information Protocol (RIP) printer */
  23
  24 /* specification: RFC 1058, RFC 2453, RFC 4822 */
  25
  26 #ifdef HAVE_CONFIG_H
  27 #include <config.h>
  28 #endif
  29
  30 #include "netdissect-stdinc.h"
  31
  32 #define ND_LONGJMP_FROM_TCHECK
  33 #include "netdissect.h"
  34 #include "addrtoname.h"
  35 #include "extract.h"
  36
  37 #include "af.h"
  38
  39
  40 /*
  41  * RFC 1058 and RFC 2453 header of packet.
  42  *
  43  *  0                   1                   2                   3 3
  44  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  45  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  46  * | Command (1)   | Version (1)   |           unused              |
  47  * +---------------+---------------+-------------------------------+
  48  */
  49 struct rip {
  50         nd_uint8_t rip_cmd;             /* request/response */
  51         nd_uint8_t rip_vers;            /* protocol version # */
  52         nd_byte    unused[2];           /* unused */
  53 };
  54
  55 #define RIPCMD_REQUEST          1       /* want info */
  56 #define RIPCMD_RESPONSE         2       /* responding to request */
  57 #define RIPCMD_TRACEON          3       /* turn tracing on */
  58 #define RIPCMD_TRACEOFF         4       /* turn it off */
  59 /* 5 is reserved */
  60 #define RIPCMD_TRIGREQ          6
  61 #define RIPCMD_TRIGRESP         7
  62 #define RIPCMD_TRIGACK          8
  63 #define RIPCMD_UPDREQ           9
  64 #define RIPCMD_UPDRESP          10
  65 #define RIPCMD_UPDACK           11
  66
  67 static const struct tok rip_cmd_values[] = {
  68     { RIPCMD_REQUEST,           "Request" },
  69     { RIPCMD_RESPONSE,          "Response" },
  70     { RIPCMD_TRACEON,           "Trace on" },
  71     { RIPCMD_TRACEOFF,          "Trace off" },
  72     { RIPCMD_TRIGREQ,           "Triggered Request" },
  73     { RIPCMD_TRIGRESP,          "Triggered Response" },
  74     { RIPCMD_TRIGACK,           "Triggered Acknowledgement" },
  75     { RIPCMD_UPDREQ,            "Update Request" },
  76     { RIPCMD_UPDRESP,           "Update Response" },
  77     { RIPCMD_UPDACK,            "Update Acknowledge" },
  78     { 0, NULL}
  79 };
  80
  81 #define RIP_AUTHLEN  16
  82 #define RIP_ROUTELEN 20
  83
  84 /*
  85  * First 4 bytes of all RIPv1/RIPv2 entries.
  86  */
  87 struct rip_entry_header {
  88         nd_uint16_t rip_family;
  89         nd_uint16_t rip_tag;
  90 };
  91
  92 /*
  93  * RFC 1058 entry.
  94  *
  95  *  0                   1                   2                   3 3
  96  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  97  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  98  * | Address Family Identifier (2) |       must be zero (2)        |
  99  * +-------------------------------+-------------------------------+
 100  * |                         IP Address (4)                        |
 101  * +---------------------------------------------------------------+
 102  * |                        must be zero (4)                       |
 103  * +---------------------------------------------------------------+
 104  * |                        must be zero (4)                       |
 105  * +---------------------------------------------------------------+
 106  * |                         Metric (4)                            |
 107  * +---------------------------------------------------------------+
 108  */
 109 struct rip_netinfo_v1 {
 110         nd_uint16_t rip_family;
 111         nd_byte     rip_mbz1[2];
 112         nd_ipv4     rip_dest;
 113         nd_byte     rip_mbz2[4];
 114         nd_byte     rip_mbz3[4];
 115         nd_uint32_t rip_metric;         /* cost of route */
 116 };
 117
 118
 119 /*
 120  * RFC 2453 route entry
 121  *
 122  *  0                   1                   2                   3 3
 123  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 124  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 125  * | Address Family Identifier (2) |        Route Tag (2)          |
 126  * +-------------------------------+-------------------------------+
 127  * |                         IP Address (4)                        |
 128  * +---------------------------------------------------------------+
 129  * |                         Subnet Mask (4)                       |
 130  * +---------------------------------------------------------------+
 131  * |                         Next Hop (4)                          |
 132  * +---------------------------------------------------------------+
 133  * |                         Metric (4)                            |
 134  * +---------------------------------------------------------------+
 135  *
 136  */
 137
 138 struct rip_netinfo_v2 {
 139         nd_uint16_t rip_family;
 140         nd_uint16_t rip_tag;
 141         nd_ipv4     rip_dest;
 142         nd_uint32_t rip_dest_mask;
 143         nd_ipv4     rip_router;
 144         nd_uint32_t rip_metric;         /* cost of route */
 145 };
 146
 147 /*
 148  * RFC 2453 authentication entry
 149  *
 150  *  0                   1                   2                   3 3
 151  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 152  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 153  * |            0xFFFF             |    Authentication Type (2)    |
 154  * +-------------------------------+-------------------------------+
 155  * -                      Authentication (16)                      -
 156  * +---------------------------------------------------------------+
 157  */
 158
 159 struct rip_auth_v2 {
 160         nd_uint16_t rip_family;
 161         nd_uint16_t rip_tag;
 162         nd_byte     rip_auth[16];
 163 };
 164
 165 /*
 166  * RFC 4822 Cryptographic Authentication entry.
 167  *
 168  *  0                   1                   2                   3 3
 169  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 170  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 171  * |     RIPv2 Packet Length       |   Key ID      | Auth Data Len |
 172  * +---------------+---------------+---------------+---------------+
 173  * |               Sequence Number (non-decreasing)                |
 174  * +---------------+---------------+---------------+---------------+
 175  * |                      reserved must be zero                    |
 176  * +---------------+---------------+---------------+---------------+
 177  * |                      reserved must be zero                    |
 178  * +---------------+---------------+---------------+---------------+
 179  */
 180 struct rip_auth_crypto_v2 {
 181         nd_uint16_t rip_packet_len;
 182         nd_uint8_t  rip_key_id;
 183         nd_uint8_t  rip_auth_data_len;
 184         nd_uint32_t rip_seq_num;
 185         nd_byte     rip_mbz1[4];
 186         nd_byte     rip_mbz2[4];
 187 };
 188
 189 static unsigned
 190 rip_entry_print_v1(netdissect_options *ndo, const u_char *p,
 191                    unsigned remaining)
 192 {
 193         const struct rip_entry_header *eh = (const struct rip_entry_header *)p;
 194         u_short family;
 195         const struct rip_netinfo_v1 *ni = (const struct rip_netinfo_v1 *)p;
 196
 197         /* RFC 1058 */
 198         if (remaining < RIP_ROUTELEN)
 199                 goto invalid;
 200         ND_TCHECK_SIZE(ni);
 201         family = GET_BE_U_2(ni->rip_family);
 202         if (family != BSD_AFNUM_INET && family != 0) {
 203                 ND_PRINT("\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family));
 204                 print_unknown_data(ndo, p + sizeof(*eh), "\n\t  ", RIP_ROUTELEN - sizeof(*eh));
 205                 return (RIP_ROUTELEN);
 206         }
 207         if (GET_BE_U_2(ni->rip_mbz1) ||
 208             GET_BE_U_4(ni->rip_mbz2) ||
 209             GET_BE_U_4(ni->rip_mbz3)) {
 210                 /* MBZ fields not zero */
 211                 print_unknown_data(ndo, p, "\n\t  ", RIP_ROUTELEN);
 212                 return (RIP_ROUTELEN);
 213         }
 214         if (family == 0) {
 215                 ND_PRINT("\n\t  AFI 0, %s, metric: %u",
 216                          GET_IPADDR_STRING(ni->rip_dest),
 217                          GET_BE_U_4(ni->rip_metric));
 218                 return (RIP_ROUTELEN);
 219         } /* BSD_AFNUM_INET */
 220         ND_PRINT("\n\t  %s, metric: %u",
 221                  GET_IPADDR_STRING(ni->rip_dest),
 222                  GET_BE_U_4(ni->rip_metric));
 223         return (RIP_ROUTELEN);
 224 invalid:
 225         return 0;
 226 }
 227
 228 static unsigned
 229 rip_entry_print_v2(netdissect_options *ndo, const u_char *p,
 230                    unsigned remaining)
 231 {
 232         const struct rip_entry_header *eh = (const struct rip_entry_header *)p;
 233         u_short family;
 234         const struct rip_netinfo_v2 *ni;
 235
 236         if (remaining < sizeof(*eh))
 237                 goto invalid;
 238         ND_TCHECK_SIZE(eh);
 239         family = GET_BE_U_2(eh->rip_family);
 240         if (family == 0xFFFF) { /* variable-sized authentication structures */
 241                 uint16_t auth_type = GET_BE_U_2(eh->rip_tag);
 242
 243                 p += sizeof(*eh);
 244                 remaining -= sizeof(*eh);
 245                 if (auth_type == 2) {
 246                         ND_PRINT("\n\t  Simple Text Authentication data: ");
 247                         nd_printjnp(ndo, p, RIP_AUTHLEN);
 248                 } else if (auth_type == 3) {
 249                         const struct rip_auth_crypto_v2 *ch;
 250
 251                         ch = (const struct rip_auth_crypto_v2 *)p;
 252                         if (remaining < sizeof(*ch))
 253                                 goto invalid;
 254                         ND_PRINT("\n\t  Auth header:");
 255                         ND_PRINT(" Packet Len %u,",
 256                                  GET_BE_U_2(ch->rip_packet_len));
 257                         ND_PRINT(" Key-ID %u,", GET_U_1(ch->rip_key_id));
 258                         ND_PRINT(" Auth Data Len %u,",
 259                                  GET_U_1(ch->rip_auth_data_len));
 260                         ND_PRINT(" SeqNo %u,", GET_BE_U_4(ch->rip_seq_num));
 261                         ND_PRINT(" MBZ %u,", GET_BE_U_4(ch->rip_mbz1));
 262                         ND_PRINT(" MBZ %u", GET_BE_U_4(ch->rip_mbz2));
 263                 } else if (auth_type == 1) {
 264                         ND_PRINT("\n\t  Auth trailer:");
 265                         print_unknown_data(ndo, p, "\n\t  ", remaining);
 266                         return (sizeof(*eh) + remaining); /* AT spans till the packet end */
 267                 } else {
 268                         ND_PRINT("\n\t  Unknown (%u) Authentication data:",
 269                                  auth_type);
 270                         print_unknown_data(ndo, p, "\n\t  ", remaining);
 271                         return (sizeof(*eh) + remaining); /* we don't know how long this is, so we go to the packet end */
 272                 }
 273         } else if (family != BSD_AFNUM_INET && family != 0) {
 274                 ND_PRINT("\n\t  AFI %s", tok2str(bsd_af_values, "Unknown (%u)", family));
 275                 print_unknown_data(ndo, p + sizeof(*eh), "\n\t  ", RIP_ROUTELEN - sizeof(*eh));
 276         } else { /* BSD_AFNUM_INET or AFI 0 */
 277                 ni = (const struct rip_netinfo_v2 *)p;
 278                 if (remaining < sizeof(*ni))
 279                         goto invalid;
 280                 ND_PRINT("\n\t  AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
 281                          tok2str(bsd_af_values, "%u", family),
 282                          GET_IPADDR_STRING(ni->rip_dest),
 283                          mask2plen(GET_BE_U_4(ni->rip_dest_mask)),
 284                          GET_BE_U_2(ni->rip_tag),
 285                          GET_BE_U_4(ni->rip_metric));
 286                 if (GET_BE_U_4(ni->rip_router))
 287                         ND_PRINT("%s", GET_IPADDR_STRING(ni->rip_router));
 288                 else
 289                         ND_PRINT("self");
 290         }
 291         return (RIP_ROUTELEN);
 292 invalid:
 293         return 0;
 294 }
 295
 296 void
 297 rip_print(netdissect_options *ndo,
 298           const u_char *p, u_int len)
 299 {
 300         const struct rip *rp;
 301         uint8_t vers, cmd;
 302         unsigned entry_size;
 303
 304         ndo->ndo_protocol = "rip";
 305         if (len < sizeof(*rp)) {
 306                 ND_PRINT(" (packet length %u)", len);
 307                 goto invalid;
 308         }
 309
 310         rp = (const struct rip *)p;
 311
 312         vers = GET_U_1(rp->rip_vers);
 313         ND_PRINT("%sRIPv%u",
 314                  (ndo->ndo_vflag >= 1) ? "\n\t" : "",
 315                  vers);
 316
 317         /* dump version and lets see if we know the commands name*/
 318         cmd = GET_U_1(rp->rip_cmd);
 319         ND_PRINT(", %s, length: %u",
 320                 tok2str(rip_cmd_values, "unknown command (%u)", cmd),
 321                 len);
 322
 323         ND_TCHECK_SIZE(rp);
 324         if (ndo->ndo_vflag < 1)
 325                 return;
 326         p += sizeof(*rp);
 327         len -= sizeof(*rp);
 328
 329         switch (cmd) {
 330
 331         case RIPCMD_REQUEST:
 332         case RIPCMD_RESPONSE:
 333                 switch (vers) {
 334
 335                 case 1:
 336                         ND_PRINT(", routes: %u", len / RIP_ROUTELEN);
 337                         while (len != 0) {
 338                                 entry_size = rip_entry_print_v1(ndo, p, len);
 339                                 if (entry_size == 0) {
 340                                         /* Error */
 341                                         goto invalid;
 342                                 }
 343                                 if (len < entry_size) {
 344                                         ND_PRINT(" [remaining entries length %u < %u]",
 345                                                  len, entry_size);
 346                                         goto invalid;
 347                                 }
 348                                 p += entry_size;
 349                                 len -= entry_size;
 350                         }
 351                         break;
 352
 353                 case 2:
 354                         ND_PRINT(", routes: %u or less", len / RIP_ROUTELEN);
 355                         while (len != 0) {
 356                                 entry_size = rip_entry_print_v2(ndo, p, len);
 357                                 if (entry_size == 0) {
 358                                         /* Error */
 359                                         goto invalid;
 360                                 }
 361                                 if (len < entry_size) {
 362                                         ND_PRINT(" [remaining entries length %u < %u]",
 363                                                  len, entry_size);
 364                                         goto invalid;
 365                                 }
 366                                 p += entry_size;
 367                                 len -= entry_size;
 368                         }
 369                         break;
 370
 371                 default:
 372                         ND_PRINT(", unknown version");
 373                         break;
 374                 }
 375                 break;
 376
 377         case RIPCMD_TRACEON:
 378         case RIPCMD_TRACEOFF:
 379         case RIPCMD_TRIGREQ:
 380         case RIPCMD_TRIGRESP:
 381         case RIPCMD_TRIGACK:
 382         case RIPCMD_UPDREQ:
 383         case RIPCMD_UPDRESP:
 384         case RIPCMD_UPDACK:
 385                 break;
 386
 387         default:
 388                 if (ndo->ndo_vflag <= 1) {
 389                         if (!print_unknown_data(ndo, p, "\n\t", len))
 390                                 return;
 391                 }
 392                 break;
 393         }
 394         /* do we want to see an additionally hexdump ? */
 395         if (ndo->ndo_vflag> 1) {
 396                 if (!print_unknown_data(ndo, p, "\n\t", len))
 397                         return;
 398         }
 399         return;
 400 invalid:
 401         nd_print_invalid(ndo);
 402         ND_TCHECK_LEN(p, len);
 403 }