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 #include "netdissect.h"
  33 #include "addrtoname.h"
  34 #include "extract.h"
  35
  36 #include "af.h"
  37
  38
  39 /*
  40  * RFC 1058 and RFC 2453 header of packet.
  41  *
  42  *  0                   1                   2                   3 3
  43  *  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
  44  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  45  * | Command (1)   | Version (1)   |           unused              |
  46  * +---------------+---------------+-------------------------------+
  47  */
  48 struct rip {
  49         nd_uint8_t rip_cmd;             /* request/response */
  50         nd_uint8_t rip_vers;            /* protocol version # */
  51         nd_byte    unused[2];           /* unused */
  52 };
  53
  54 #define RIPCMD_REQUEST          1       /* want info */
  55 #define RIPCMD_RESPONSE         2       /* responding to request */
  56 #define RIPCMD_TRACEON          3       /* turn tracing on */
  57 #define RIPCMD_TRACEOFF         4       /* turn it off */
  58 /* 5 is reserved */
  59 #define RIPCMD_TRIGREQ          6
  60 #define RIPCMD_TRIGRESP         7
  61 #define RIPCMD_TRIGACK          8
  62 #define RIPCMD_UPDREQ           9
  63 #define RIPCMD_UPDRESP          10
  64 #define RIPCMD_UPDACK           11
  65
  66 static const struct tok rip_cmd_values[] = {
  67     { RIPCMD_REQUEST,           "Request" },
  68     { RIPCMD_RESPONSE,          "Response" },
  69     { RIPCMD_TRACEON,           "Trace on" },
  70     { RIPCMD_TRACEOFF,          "Trace off" },
  71     { RIPCMD_TRIGREQ,           "Triggered Request" },
  72     { RIPCMD_TRIGRESP,          "Triggered Response" },
  73     { RIPCMD_TRIGACK,           "Triggered Acknowledgement" },
  74     { RIPCMD_UPDREQ,            "Update Request" },
  75     { RIPCMD_UPDRESP,           "Update Response" },
  76     { RIPCMD_UPDACK,            "Update Acknowledge" },
  77     { 0, NULL}
  78 };
  79
  80 #define RIP_AUTHLEN  16
  81 #define RIP_ROUTELEN 20
  82
  83 /*
  84  * First 4 bytes of all RIPv1/RIPv2 entries.
  85  */
  86 struct rip_entry_header {
  87         nd_uint16_t rip_family;
  88         nd_uint16_t rip_tag;
  89 };
  90
  91 /*
  92  * RFC 1058 entry.
  93  *
  94  *  0                   1                   2                   3 3
  95  *  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
  96  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  97  * | Address Family Identifier (2) |       must be zero (2)        |
  98  * +-------------------------------+-------------------------------+
  99  * |                         IP Address (4)                        |
 100  * +---------------------------------------------------------------+
 101  * |                        must be zero (4)                       |
 102  * +---------------------------------------------------------------+
 103  * |                        must be zero (4)                       |
 104  * +---------------------------------------------------------------+
 105  * |                         Metric (4)                            |
 106  * +---------------------------------------------------------------+
 107  */
 108 struct rip_netinfo_v1 {
 109         nd_uint16_t rip_family;
 110         nd_byte     rip_mbz1[2];
 111         nd_ipv4     rip_dest;
 112         nd_byte     rip_mbz2[4];
 113         nd_byte     rip_mbz3[4];
 114         nd_uint32_t rip_metric;         /* cost of route */
 115 };
 116
 117
 118 /*
 119  * RFC 2453 route entry
 120  *
 121  *  0                   1                   2                   3 3
 122  *  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
 123  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 124  * | Address Family Identifier (2) |        Route Tag (2)          |
 125  * +-------------------------------+-------------------------------+
 126  * |                         IP Address (4)                        |
 127  * +---------------------------------------------------------------+
 128  * |                         Subnet Mask (4)                       |
 129  * +---------------------------------------------------------------+
 130  * |                         Next Hop (4)                          |
 131  * +---------------------------------------------------------------+
 132  * |                         Metric (4)                            |
 133  * +---------------------------------------------------------------+
 134  *
 135  */
 136
 137 struct rip_netinfo_v2 {
 138         nd_uint16_t rip_family;
 139         nd_uint16_t rip_tag;
 140         nd_ipv4     rip_dest;
 141         nd_uint32_t rip_dest_mask;
 142         nd_ipv4     rip_router;
 143         nd_uint32_t rip_metric;         /* cost of route */
 144 };
 145
 146 /*
 147  * RFC 2453 authentication entry
 148  *
 149  *  0                   1                   2                   3 3
 150  *  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
 151  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 152  * |            0xFFFF             |    Authentication Type (2)    |
 153  * +-------------------------------+-------------------------------+
 154  * -                      Authentication (16)                      -
 155  * +---------------------------------------------------------------+
 156  */
 157
 158 struct rip_auth_v2 {
 159         nd_uint16_t rip_family;
 160         nd_uint16_t rip_tag;
 161         nd_byte     rip_auth[16];
 162 };
 163
 164 /*
 165  * RFC 4822 Cryptographic Authentication entry.
 166  *
 167  *  0                   1                   2                   3 3
 168  *  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
 169  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 170  * |     RIPv2 Packet Length       |   Key ID      | Auth Data Len |
 171  * +---------------+---------------+---------------+---------------+
 172  * |               Sequence Number (non-decreasing)                |
 173  * +---------------+---------------+---------------+---------------+
 174  * |                      reserved must be zero                    |
 175  * +---------------+---------------+---------------+---------------+
 176  * |                      reserved must be zero                    |
 177  * +---------------+---------------+---------------+---------------+
 178  */
 179 struct rip_auth_crypto_v2 {
 180         nd_uint16_t rip_packet_len;
 181         nd_uint8_t  rip_key_id;
 182         nd_uint8_t  rip_auth_data_len;
 183         nd_uint32_t rip_seq_num;
 184         nd_byte     rip_mbz1[4];
 185         nd_byte     rip_mbz2[4];
 186 };
 187
 188 static unsigned
 189 rip_entry_print_v1(netdissect_options *ndo, const u_char *p,
 190                    unsigned remaining)
 191 {
 192         const struct rip_entry_header *eh = (const struct rip_entry_header *)p;
 193         u_short family;
 194         const struct rip_netinfo_v1 *ni = (const struct rip_netinfo_v1 *)p;
 195
 196         /* RFC 1058 */
 197         if (remaining < RIP_ROUTELEN)
 198                 return (0);
 199         ND_TCHECK_SIZE(ni);
 200         family = GET_BE_U_2(ni->rip_family);
 201         if (family != BSD_AFNUM_INET && family != 0) {
 202                 ND_PRINT("\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family));
 203                 print_unknown_data(ndo, p + sizeof(*eh), "\n\t  ", RIP_ROUTELEN - sizeof(*eh));
 204                 return (RIP_ROUTELEN);
 205         }
 206         if (GET_BE_U_2(ni->rip_mbz1) ||
 207             GET_BE_U_4(ni->rip_mbz2) ||
 208             GET_BE_U_4(ni->rip_mbz3)) {
 209                 /* MBZ fields not zero */
 210                 print_unknown_data(ndo, p, "\n\t  ", RIP_ROUTELEN);
 211                 return (RIP_ROUTELEN);
 212         }
 213         if (family == 0) {
 214                 ND_PRINT("\n\t  AFI 0, %s, metric: %u",
 215                          GET_IPADDR_STRING(ni->rip_dest),
 216                          GET_BE_U_4(ni->rip_metric));
 217                 return (RIP_ROUTELEN);
 218         } /* BSD_AFNUM_INET */
 219         ND_PRINT("\n\t  %s, metric: %u",
 220                  GET_IPADDR_STRING(ni->rip_dest),
 221                  GET_BE_U_4(ni->rip_metric));
 222         return (RIP_ROUTELEN);
 223 trunc:
 224         return 0;
 225 }
 226
 227 static unsigned
 228 rip_entry_print_v2(netdissect_options *ndo, const u_char *p,
 229                    unsigned remaining)
 230 {
 231         const struct rip_entry_header *eh = (const struct rip_entry_header *)p;
 232         u_short family;
 233         const struct rip_netinfo_v2 *ni;
 234
 235         if (remaining < sizeof(*eh))
 236                 return (0);
 237         ND_TCHECK_SIZE(eh);
 238         family = GET_BE_U_2(eh->rip_family);
 239         if (family == 0xFFFF) { /* variable-sized authentication structures */
 240                 uint16_t auth_type = GET_BE_U_2(eh->rip_tag);
 241
 242                 p += sizeof(*eh);
 243                 remaining -= sizeof(*eh);
 244                 if (auth_type == 2) {
 245                         ND_PRINT("\n\t  Simple Text Authentication data: ");
 246                         nd_printjnp(ndo, p, RIP_AUTHLEN);
 247                 } else if (auth_type == 3) {
 248                         const struct rip_auth_crypto_v2 *ch;
 249
 250                         ch = (const struct rip_auth_crypto_v2 *)p;
 251                         ND_TCHECK_SIZE(ch);
 252                         if (remaining < sizeof(*ch))
 253                                 return (0);
 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                 ND_TCHECK_SIZE(ni);
 279                 if (remaining < sizeof(*ni))
 280                         return (0);
 281                 ND_PRINT("\n\t  AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
 282                          tok2str(bsd_af_values, "%u", family),
 283                          GET_IPADDR_STRING(ni->rip_dest),
 284                          mask2plen(GET_BE_U_4(ni->rip_dest_mask)),
 285                          GET_BE_U_2(ni->rip_tag),
 286                          GET_BE_U_4(ni->rip_metric));
 287                 if (GET_BE_U_4(ni->rip_router))
 288                         ND_PRINT("%s", GET_IPADDR_STRING(ni->rip_router));
 289                 else
 290                         ND_PRINT("self");
 291         }
 292         return (RIP_ROUTELEN);
 293 trunc:
 294         return 0;
 295 }
 296
 297 void
 298 rip_print(netdissect_options *ndo,
 299           const u_char *dat, u_int length)
 300 {
 301         const struct rip *rp;
 302         uint8_t vers, cmd;
 303         const u_char *p;
 304         u_int len, routecount;
 305         unsigned entry_size;
 306
 307         ndo->ndo_protocol = "rip";
 308         if (ndo->ndo_snapend < dat) {
 309                 nd_print_trunc(ndo);
 310                 return;
 311         }
 312         len = ND_BYTES_AVAILABLE_AFTER(dat);
 313         if (len > length)
 314                 len = length;
 315         if (len < sizeof(*rp)) {
 316                 nd_print_trunc(ndo);
 317                 return;
 318         }
 319         len -= sizeof(*rp);
 320
 321         rp = (const struct rip *)dat;
 322
 323         ND_TCHECK_SIZE(rp);
 324         vers = GET_U_1(rp->rip_vers);
 325         ND_PRINT("%sRIPv%u",
 326                  (ndo->ndo_vflag >= 1) ? "\n\t" : "",
 327                  vers);
 328
 329         /* dump version and lets see if we know the commands name*/
 330         cmd = GET_U_1(rp->rip_cmd);
 331         ND_PRINT(", %s, length: %u",
 332                 tok2str(rip_cmd_values, "unknown command (%u)", cmd),
 333                 length);
 334
 335         if (ndo->ndo_vflag < 1)
 336                 return;
 337
 338         switch (cmd) {
 339
 340         case RIPCMD_REQUEST:
 341         case RIPCMD_RESPONSE:
 342                 switch (vers) {
 343
 344                 case 1:
 345                         routecount = length / RIP_ROUTELEN;
 346                         ND_PRINT(", routes: %u", routecount);
 347                         p = (const u_char *)(rp + 1);
 348                         while (len != 0) {
 349                                 entry_size = rip_entry_print_v1(ndo, p, len);
 350                                 if (entry_size == 0) {
 351                                         /* Error */
 352                                         nd_print_trunc(ndo);
 353                                         break;
 354                                 }
 355                                 if (len < entry_size) {
 356                                         ND_PRINT(" [remaining entries length %u < %u]",
 357                                                  len, entry_size);
 358                                         nd_print_invalid(ndo);
 359                                         break;
 360                                 }
 361                                 p += entry_size;
 362                                 len -= entry_size;
 363                         }
 364                         break;
 365
 366                 case 2:
 367                         routecount = length / RIP_ROUTELEN;
 368                         ND_PRINT(", routes: %u or less", routecount);
 369                         p = (const u_char *)(rp + 1);
 370                         while (len != 0) {
 371                                 entry_size = rip_entry_print_v2(ndo, p, len);
 372                                 if (entry_size == 0) {
 373                                         /* Error */
 374                                         nd_print_trunc(ndo);
 375                                         break;
 376                                 }
 377                                 if (len < entry_size) {
 378                                         ND_PRINT(" [remaining entries length %u < %u]",
 379                                                  len, entry_size);
 380                                         nd_print_invalid(ndo);
 381                                         break;
 382                                 }
 383                                 p += entry_size;
 384                                 len -= entry_size;
 385                         }
 386                         break;
 387
 388                 default:
 389                         ND_PRINT(", unknown version");
 390                         break;
 391                 }
 392                 break;
 393
 394         case RIPCMD_TRACEON:
 395         case RIPCMD_TRACEOFF:
 396         case RIPCMD_TRIGREQ:
 397         case RIPCMD_TRIGRESP:
 398         case RIPCMD_TRIGACK:
 399         case RIPCMD_UPDREQ:
 400         case RIPCMD_UPDRESP:
 401         case RIPCMD_UPDACK:
 402                 break;
 403
 404         default:
 405                 if (ndo->ndo_vflag <= 1) {
 406                         if (!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
 407                                 return;
 408                 }
 409                 break;
 410         }
 411         /* do we want to see an additionally hexdump ? */
 412         if (ndo->ndo_vflag> 1) {
 413                 if (!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
 414                         return;
 415         }
 416 trunc:
 417         return;
 418 }