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