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 #include <config.h>
  27
  28 #include "netdissect-stdinc.h"
  29
  30 #include "netdissect.h"
  31 #include "addrtoname.h"
  32 #include "extract.h"
  33
  34 #include "af.h"
  35
  36
  37 /*
  38  * RFC 1058 and RFC 2453 header of packet.
  39  *
  40  *  0                   1                   2                   3 3
  41  *  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
  42  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  43  * | Command (1)   | Version (1)   |           unused              |
  44  * +---------------+---------------+-------------------------------+
  45  */
  46 struct rip {
  47         nd_uint8_t rip_cmd;             /* request/response */
  48         nd_uint8_t rip_vers;            /* protocol version # */
  49         nd_byte    unused[2];           /* unused */
  50 };
  51
  52 #define RIPCMD_REQUEST          1       /* want info */
  53 #define RIPCMD_RESPONSE         2       /* responding to request */
  54 #define RIPCMD_TRACEON          3       /* turn tracing on */
  55 #define RIPCMD_TRACEOFF         4       /* turn it off */
  56 /* 5 is reserved */
  57 #define RIPCMD_TRIGREQ          6
  58 #define RIPCMD_TRIGRESP         7
  59 #define RIPCMD_TRIGACK          8
  60 #define RIPCMD_UPDREQ           9
  61 #define RIPCMD_UPDRESP          10
  62 #define RIPCMD_UPDACK           11
  63
  64 static const struct tok rip_cmd_values[] = {
  65     { RIPCMD_REQUEST,           "Request" },
  66     { RIPCMD_RESPONSE,          "Response" },
  67     { RIPCMD_TRACEON,           "Trace on" },
  68     { RIPCMD_TRACEOFF,          "Trace off" },
  69     { RIPCMD_TRIGREQ,           "Triggered Request" },
  70     { RIPCMD_TRIGRESP,          "Triggered Response" },
  71     { RIPCMD_TRIGACK,           "Triggered Acknowledgement" },
  72     { RIPCMD_UPDREQ,            "Update Request" },
  73     { RIPCMD_UPDRESP,           "Update Response" },
  74     { RIPCMD_UPDACK,            "Update Acknowledge" },
  75     { 0, NULL}
  76 };
  77
  78 #define RIP_AUTHLEN  16
  79 #define RIP_ROUTELEN 20
  80
  81 /*
  82  * First 4 bytes of all RIPv1/RIPv2 entries.
  83  */
  84 struct rip_entry_header {
  85         nd_uint16_t rip_family;
  86         nd_uint16_t rip_tag;
  87 };
  88
  89 /*
  90  * RFC 1058 entry.
  91  *
  92  *  0                   1                   2                   3 3
  93  *  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
  94  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  95  * | Address Family Identifier (2) |       must be zero (2)        |
  96  * +-------------------------------+-------------------------------+
  97  * |                         IP Address (4)                        |
  98  * +---------------------------------------------------------------+
  99  * |                        must be zero (4)                       |
 100  * +---------------------------------------------------------------+
 101  * |                        must be zero (4)                       |
 102  * +---------------------------------------------------------------+
 103  * |                         Metric (4)                            |
 104  * +---------------------------------------------------------------+
 105  */
 106 struct rip_netinfo_v1 {
 107         nd_uint16_t rip_family;
 108         nd_byte     rip_mbz1[2];
 109         nd_ipv4     rip_dest;
 110         nd_byte     rip_mbz2[4];
 111         nd_byte     rip_mbz3[4];
 112         nd_uint32_t rip_metric;         /* cost of route */
 113 };
 114
 115
 116 /*
 117  * RFC 2453 route entry
 118  *
 119  *  0                   1                   2                   3 3
 120  *  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
 121  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 122  * | Address Family Identifier (2) |        Route Tag (2)          |
 123  * +-------------------------------+-------------------------------+
 124  * |                         IP Address (4)                        |
 125  * +---------------------------------------------------------------+
 126  * |                         Subnet Mask (4)                       |
 127  * +---------------------------------------------------------------+
 128  * |                         Next Hop (4)                          |
 129  * +---------------------------------------------------------------+
 130  * |                         Metric (4)                            |
 131  * +---------------------------------------------------------------+
 132  *
 133  */
 134
 135 struct rip_netinfo_v2 {
 136         nd_uint16_t rip_family;
 137         nd_uint16_t rip_tag;
 138         nd_ipv4     rip_dest;
 139         nd_uint32_t rip_dest_mask;
 140         nd_ipv4     rip_router;
 141         nd_uint32_t rip_metric;         /* cost of route */
 142 };
 143
 144 /*
 145  * RFC 2453 authentication entry
 146  *
 147  *  0                   1                   2                   3 3
 148  *  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
 149  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 150  * |            0xFFFF             |    Authentication Type (2)    |
 151  * +-------------------------------+-------------------------------+
 152  * -                      Authentication (16)                      -
 153  * +---------------------------------------------------------------+
 154  */
 155
 156 struct rip_auth_v2 {
 157         nd_uint16_t rip_family;
 158         nd_uint16_t rip_tag;
 159         nd_byte     rip_auth[16];
 160 };
 161
 162 /*
 163  * RFC 4822 Cryptographic Authentication entry.
 164  *
 165  *  0                   1                   2                   3 3
 166  *  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
 167  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 168  * |     RIPv2 Packet Length       |   Key ID      | Auth Data Len |
 169  * +---------------+---------------+---------------+---------------+
 170  * |               Sequence Number (non-decreasing)                |
 171  * +---------------+---------------+---------------+---------------+
 172  * |                      reserved must be zero                    |
 173  * +---------------+---------------+---------------+---------------+
 174  * |                      reserved must be zero                    |
 175  * +---------------+---------------+---------------+---------------+
 176  */
 177 struct rip_auth_crypto_v2 {
 178         nd_uint16_t rip_packet_len;
 179         nd_uint8_t  rip_key_id;
 180         nd_uint8_t  rip_auth_data_len;
 181         nd_uint32_t rip_seq_num;
 182         nd_byte     rip_mbz1[4];
 183         nd_byte     rip_mbz2[4];
 184 };
 185
 186 static unsigned
 187 rip_entry_print_v1(netdissect_options *ndo, const u_char *p,
 188                    unsigned remaining)
 189 {
 190         const struct rip_entry_header *eh = (const struct rip_entry_header *)p;
 191         u_short family;
 192         const struct rip_netinfo_v1 *ni = (const struct rip_netinfo_v1 *)p;
 193
 194         /* RFC 1058 */
 195         if (remaining < RIP_ROUTELEN)
 196                 return (0);
 197         ND_TCHECK_SIZE(ni);
 198         family = GET_BE_U_2(ni->rip_family);
 199         if (family != BSD_AFNUM_INET && family != 0) {
 200                 ND_PRINT("\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family));
 201                 print_unknown_data(ndo, p + sizeof(*eh), "\n\t  ", RIP_ROUTELEN - sizeof(*eh));
 202                 return (RIP_ROUTELEN);
 203         }
 204         if (GET_BE_U_2(ni->rip_mbz1) ||
 205             GET_BE_U_4(ni->rip_mbz2) ||
 206             GET_BE_U_4(ni->rip_mbz3)) {
 207                 /* MBZ fields not zero */
 208                 print_unknown_data(ndo, p, "\n\t  ", RIP_ROUTELEN);
 209                 return (RIP_ROUTELEN);
 210         }
 211         if (family == 0) {
 212                 ND_PRINT("\n\t  AFI 0, %s, metric: %u",
 213                          GET_IPADDR_STRING(ni->rip_dest),
 214                          GET_BE_U_4(ni->rip_metric));
 215                 return (RIP_ROUTELEN);
 216         } /* BSD_AFNUM_INET */
 217         ND_PRINT("\n\t  %s, metric: %u",
 218                  GET_IPADDR_STRING(ni->rip_dest),
 219                  GET_BE_U_4(ni->rip_metric));
 220         return (RIP_ROUTELEN);
 221 trunc:
 222         return 0;
 223 }
 224
 225 static unsigned
 226 rip_entry_print_v2(netdissect_options *ndo, const u_char *p,
 227                    unsigned remaining)
 228 {
 229         const struct rip_entry_header *eh = (const struct rip_entry_header *)p;
 230         u_short family;
 231         const struct rip_netinfo_v2 *ni;
 232
 233         if (remaining < sizeof(*eh))
 234                 return (0);
 235         ND_TCHECK_SIZE(eh);
 236         family = GET_BE_U_2(eh->rip_family);
 237         if (family == 0xFFFF) { /* variable-sized authentication structures */
 238                 uint16_t auth_type = GET_BE_U_2(eh->rip_tag);
 239
 240                 p += sizeof(*eh);
 241                 remaining -= sizeof(*eh);
 242                 if (auth_type == 2) {
 243                         ND_PRINT("\n\t  Simple Text Authentication data: ");
 244                         nd_printjnp(ndo, p, RIP_AUTHLEN);
 245                 } else if (auth_type == 3) {
 246                         const struct rip_auth_crypto_v2 *ch;
 247
 248                         ch = (const struct rip_auth_crypto_v2 *)p;
 249                         ND_TCHECK_SIZE(ch);
 250                         if (remaining < sizeof(*ch))
 251                                 return (0);
 252                         ND_PRINT("\n\t  Auth header:");
 253                         ND_PRINT(" Packet Len %u,",
 254                                  GET_BE_U_2(ch->rip_packet_len));
 255                         ND_PRINT(" Key-ID %u,", GET_U_1(ch->rip_key_id));
 256                         ND_PRINT(" Auth Data Len %u,",
 257                                  GET_U_1(ch->rip_auth_data_len));
 258                         ND_PRINT(" SeqNo %u,", GET_BE_U_4(ch->rip_seq_num));
 259                         ND_PRINT(" MBZ %u,", GET_BE_U_4(ch->rip_mbz1));
 260                         ND_PRINT(" MBZ %u", GET_BE_U_4(ch->rip_mbz2));
 261                 } else if (auth_type == 1) {
 262                         ND_PRINT("\n\t  Auth trailer:");
 263                         print_unknown_data(ndo, p, "\n\t  ", remaining);
 264                         return (sizeof(*eh) + remaining); /* AT spans till the packet end */
 265                 } else {
 266                         ND_PRINT("\n\t  Unknown (%u) Authentication data:",
 267                                  auth_type);
 268                         print_unknown_data(ndo, p, "\n\t  ", remaining);
 269                         return (sizeof(*eh) + remaining); /* we don't know how long this is, so we go to the packet end */
 270                 }
 271         } else if (family != BSD_AFNUM_INET && family != 0) {
 272                 ND_PRINT("\n\t  AFI %s", tok2str(bsd_af_values, "Unknown (%u)", family));
 273                 print_unknown_data(ndo, p + sizeof(*eh), "\n\t  ", RIP_ROUTELEN - sizeof(*eh));
 274         } else { /* BSD_AFNUM_INET or AFI 0 */
 275                 ni = (const struct rip_netinfo_v2 *)p;
 276                 ND_TCHECK_SIZE(ni);
 277                 if (remaining < sizeof(*ni))
 278                         return (0);
 279                 ND_PRINT("\n\t  AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
 280                          tok2str(bsd_af_values, "%u", family),
 281                          GET_IPADDR_STRING(ni->rip_dest),
 282                          mask2plen(GET_BE_U_4(ni->rip_dest_mask)),
 283                          GET_BE_U_2(ni->rip_tag),
 284                          GET_BE_U_4(ni->rip_metric));
 285                 if (GET_BE_U_4(ni->rip_router))
 286                         ND_PRINT("%s", GET_IPADDR_STRING(ni->rip_router));
 287                 else
 288                         ND_PRINT("self");
 289         }
 290         return (RIP_ROUTELEN);
 291 trunc:
 292         return 0;
 293 }
 294
 295 void
 296 rip_print(netdissect_options *ndo,
 297           const u_char *dat, u_int length)
 298 {
 299         const struct rip *rp;
 300         uint8_t vers, cmd;
 301         const u_char *p;
 302         u_int len, routecount;
 303         unsigned entry_size;
 304
 305         ndo->ndo_protocol = "rip";
 306         if (ndo->ndo_snapend < dat) {
 307                 nd_print_trunc(ndo);
 308                 return;
 309         }
 310         len = ND_BYTES_AVAILABLE_AFTER(dat);
 311         if (len > length)
 312                 len = length;
 313         if (len < sizeof(*rp)) {
 314                 nd_print_trunc(ndo);
 315                 return;
 316         }
 317         len -= sizeof(*rp);
 318
 319         rp = (const struct rip *)dat;
 320
 321         ND_TCHECK_SIZE(rp);
 322         vers = GET_U_1(rp->rip_vers);
 323         ND_PRINT("%sRIPv%u",
 324                  (ndo->ndo_vflag >= 1) ? "\n\t" : "",
 325                  vers);
 326
 327         /* dump version and lets see if we know the commands name*/
 328         cmd = GET_U_1(rp->rip_cmd);
 329         ND_PRINT(", %s, length: %u",
 330                 tok2str(rip_cmd_values, "unknown command (%u)", cmd),
 331                 length);
 332
 333         if (ndo->ndo_vflag < 1)
 334                 return;
 335
 336         switch (cmd) {
 337
 338         case RIPCMD_REQUEST:
 339         case RIPCMD_RESPONSE:
 340                 switch (vers) {
 341
 342                 case 1:
 343                         routecount = length / RIP_ROUTELEN;
 344                         ND_PRINT(", routes: %u", routecount);
 345                         p = (const u_char *)(rp + 1);
 346                         while (len != 0) {
 347                                 entry_size = rip_entry_print_v1(ndo, p, len);
 348                                 if (entry_size == 0) {
 349                                         /* Error */
 350                                         nd_print_trunc(ndo);
 351                                         break;
 352                                 }
 353                                 if (len < entry_size) {
 354                                         ND_PRINT(" [remaining entries length %u < %u]",
 355                                                  len, entry_size);
 356                                         nd_print_invalid(ndo);
 357                                         break;
 358                                 }
 359                                 p += entry_size;
 360                                 len -= entry_size;
 361                         }
 362                         break;
 363
 364                 case 2:
 365                         routecount = length / RIP_ROUTELEN;
 366                         ND_PRINT(", routes: %u or less", routecount);
 367                         p = (const u_char *)(rp + 1);
 368                         while (len != 0) {
 369                                 entry_size = rip_entry_print_v2(ndo, p, len);
 370                                 if (entry_size == 0) {
 371                                         /* Error */
 372                                         nd_print_trunc(ndo);
 373                                         break;
 374                                 }
 375                                 if (len < entry_size) {
 376                                         ND_PRINT(" [remaining entries length %u < %u]",
 377                                                  len, entry_size);
 378                                         nd_print_invalid(ndo);
 379                                         break;
 380                                 }
 381                                 p += entry_size;
 382                                 len -= entry_size;
 383                         }
 384                         break;
 385
 386                 default:
 387                         ND_PRINT(", unknown version");
 388                         break;
 389                 }
 390                 break;
 391
 392         case RIPCMD_TRACEON:
 393         case RIPCMD_TRACEOFF:
 394         case RIPCMD_TRIGREQ:
 395         case RIPCMD_TRIGRESP:
 396         case RIPCMD_TRIGACK:
 397         case RIPCMD_UPDREQ:
 398         case RIPCMD_UPDRESP:
 399         case RIPCMD_UPDACK:
 400                 break;
 401
 402         default:
 403                 if (ndo->ndo_vflag <= 1) {
 404                         if (!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
 405                                 return;
 406                 }
 407                 break;
 408         }
 409         /* do we want to see an additionally hexdump ? */
 410         if (ndo->ndo_vflag> 1) {
 411                 if (!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
 412                         return;
 413         }
 414 trunc:
 415         return;
 416 }