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 */
  25
  26 #ifdef HAVE_CONFIG_H
  27 #include "config.h"
  28 #endif
  29
  30 #include <netdissect-stdinc.h>
  31
  32 #include <stdio.h>
  33
  34 #include "netdissect.h"
  35 #include "addrtoname.h"
  36 #include "extract.h"
  37
  38 #include "af.h"
  39
  40 static const char tstr[] = "[|rip]";
  41
  42 struct rip {
  43         nd_uint8_t rip_cmd;             /* request/response */
  44         nd_uint8_t rip_vers;            /* protocol version # */
  45         nd_byte    unused[2];           /* unused */
  46 };
  47
  48 #define RIPCMD_REQUEST          1       /* want info */
  49 #define RIPCMD_RESPONSE         2       /* responding to request */
  50 #define RIPCMD_TRACEON          3       /* turn tracing on */
  51 #define RIPCMD_TRACEOFF         4       /* turn it off */
  52 #define RIPCMD_POLL             5       /* want info from everybody */
  53 #define RIPCMD_POLLENTRY        6       /* poll for entry */
  54
  55 static const struct tok rip_cmd_values[] = {
  56     { RIPCMD_REQUEST,           "Request" },
  57     { RIPCMD_RESPONSE,          "Response" },
  58     { RIPCMD_TRACEON,           "Trace on" },
  59     { RIPCMD_TRACEOFF,          "Trace off" },
  60     { RIPCMD_POLL,              "Poll" },
  61     { RIPCMD_POLLENTRY,         "Poll Entry" },
  62     { 0, NULL}
  63 };
  64
  65 #define RIP_AUTHLEN  16
  66 #define RIP_ROUTELEN 20
  67
  68 /*
  69  * rfc 1723
  70  *
  71  *  0                   1                   2                   3 3
  72  *  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
  73  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  74  * | Command (1)   | Version (1)   |           unused              |
  75  * +---------------+---------------+-------------------------------+
  76  * | Address Family Identifier (2) |        Route Tag (2)          |
  77  * +-------------------------------+-------------------------------+
  78  * |                         IP Address (4)                        |
  79  * +---------------------------------------------------------------+
  80  * |                         Subnet Mask (4)                       |
  81  * +---------------------------------------------------------------+
  82  * |                         Next Hop (4)                          |
  83  * +---------------------------------------------------------------+
  84  * |                         Metric (4)                            |
  85  * +---------------------------------------------------------------+
  86  *
  87  */
  88
  89 struct rip_netinfo {
  90         nd_uint16_t rip_family;
  91         nd_uint16_t rip_tag;
  92         nd_uint32_t rip_dest;
  93         nd_uint32_t rip_dest_mask;
  94         nd_uint32_t rip_router;
  95         nd_uint32_t rip_metric;         /* cost of route */
  96 };
  97
  98 static void
  99 rip_entry_print_v1(netdissect_options *ndo,
 100                    const struct rip_netinfo *ni)
 101 {
 102         u_short family;
 103
 104         /* RFC 1058 */
 105         family = EXTRACT_BE_U_2(ni->rip_family);
 106         if (family != BSD_AFNUM_INET && family != 0) {
 107                 ND_PRINT("\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family));
 108                 print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
 109                 return;
 110         }
 111         if (EXTRACT_BE_U_2(ni->rip_tag) ||
 112             EXTRACT_BE_U_4(ni->rip_dest_mask) ||
 113             EXTRACT_BE_U_4(ni->rip_router)) {
 114                 /* MBZ fields not zero */
 115                 print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
 116                 return;
 117         }
 118         if (family == 0) {
 119                 ND_PRINT("\n\t  AFI 0, %s, metric: %u",
 120                         ipaddr_string(ndo, &ni->rip_dest),
 121                         EXTRACT_BE_U_4(ni->rip_metric));
 122                 return;
 123         } /* BSD_AFNUM_INET */
 124         ND_PRINT("\n\t  %s, metric: %u",
 125                ipaddr_string(ndo, &ni->rip_dest),
 126                EXTRACT_BE_U_4(ni->rip_metric));
 127 }
 128
 129 static unsigned
 130 rip_entry_print_v2(netdissect_options *ndo,
 131                    const struct rip_netinfo *ni, const unsigned remaining)
 132 {
 133         u_short family;
 134
 135         family = EXTRACT_BE_U_2(ni->rip_family);
 136         if (family == 0xFFFF) { /* variable-sized authentication structures */
 137                 uint16_t auth_type = EXTRACT_BE_U_2(ni->rip_tag);
 138                 if (auth_type == 2) {
 139                         const u_char *p = (const u_char *)&ni->rip_dest;
 140                         u_int i = 0;
 141                         ND_PRINT("\n\t  Simple Text Authentication data: ");
 142                         for (; i < RIP_AUTHLEN; p++, i++)
 143                                 ND_PRINT("%c",
 144                                          ND_ISPRINT(EXTRACT_U_1(p)) ? EXTRACT_U_1(p) : '.');
 145                 } else if (auth_type == 3) {
 146                         ND_PRINT("\n\t  Auth header:");
 147                         ND_PRINT(" Packet Len %u,", EXTRACT_BE_U_2((const uint8_t *)ni + 4));
 148                         ND_PRINT(" Key-ID %u,", EXTRACT_U_1((const uint8_t *)ni + 6));
 149                         ND_PRINT(" Auth Data Len %u,", EXTRACT_U_1((const uint8_t *)ni + 7));
 150                         ND_PRINT(" SeqNo %u,", EXTRACT_BE_U_4(ni->rip_dest_mask));
 151                         ND_PRINT(" MBZ %u,", EXTRACT_BE_U_4(ni->rip_router));
 152                         ND_PRINT(" MBZ %u", EXTRACT_BE_U_4(ni->rip_metric));
 153                 } else if (auth_type == 1) {
 154                         ND_PRINT("\n\t  Auth trailer:");
 155                         print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
 156                         return remaining; /* AT spans till the packet end */
 157                 } else {
 158                         ND_PRINT("\n\t  Unknown (%u) Authentication data:",
 159                                EXTRACT_BE_U_2(ni->rip_tag));
 160                         print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
 161                 }
 162         } else if (family != BSD_AFNUM_INET && family != 0) {
 163                 ND_PRINT("\n\t  AFI %s", tok2str(bsd_af_values, "Unknown (%u)", family));
 164                 print_unknown_data(ndo, (const uint8_t *)&ni->rip_tag, "\n\t  ", RIP_ROUTELEN-2);
 165         } else { /* BSD_AFNUM_INET or AFI 0 */
 166                 ND_PRINT("\n\t  AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
 167                        tok2str(bsd_af_values, "%u", family),
 168                        ipaddr_string(ndo, &ni->rip_dest),
 169                        mask2plen(EXTRACT_BE_U_4(ni->rip_dest_mask)),
 170                        EXTRACT_BE_U_2(ni->rip_tag),
 171                        EXTRACT_BE_U_4(ni->rip_metric));
 172                 if (EXTRACT_BE_U_4(ni->rip_router))
 173                         ND_PRINT("%s", ipaddr_string(ndo, &ni->rip_router));
 174                 else
 175                         ND_PRINT("self");
 176         }
 177         return sizeof (*ni);
 178 }
 179
 180 void
 181 rip_print(netdissect_options *ndo,
 182           const u_char *dat, u_int length)
 183 {
 184         const struct rip *rp;
 185         uint8_t vers, cmd;
 186         const struct rip_netinfo *ni;
 187         u_int i, j;
 188
 189         if (ndo->ndo_snapend < dat) {
 190                 ND_PRINT(" %s", tstr);
 191                 return;
 192         }
 193         i = ndo->ndo_snapend - dat;
 194         if (i > length)
 195                 i = length;
 196         if (i < sizeof(*rp)) {
 197                 ND_PRINT(" %s", tstr);
 198                 return;
 199         }
 200         i -= sizeof(*rp);
 201
 202         rp = (const struct rip *)dat;
 203
 204         vers = EXTRACT_U_1(rp->rip_vers);
 205         ND_PRINT("%sRIPv%u",
 206                (ndo->ndo_vflag >= 1) ? "\n\t" : "",
 207                vers);
 208
 209         switch (vers) {
 210         case 0:
 211                 /*
 212                  * RFC 1058.
 213                  *
 214                  * XXX - RFC 1058 says
 215                  *
 216                  * 0  Datagrams whose version number is zero are to be ignored.
 217                  *    These are from a previous version of the protocol, whose
 218                  *    packet format was machine-specific.
 219                  *
 220                  * so perhaps we should just dump the packet, in hex.
 221                  */
 222                 print_unknown_data(ndo, (const uint8_t *)&rp->rip_cmd, "\n\t", length);
 223                 break;
 224         default:
 225                 /* dump version and lets see if we know the commands name*/
 226                 cmd = EXTRACT_U_1(rp->rip_cmd);
 227                 ND_PRINT(", %s, length: %u",
 228                        tok2str(rip_cmd_values,
 229                                "unknown command (%u)",
 230                                cmd),
 231                        length);
 232
 233                 if (ndo->ndo_vflag < 1)
 234                     return;
 235
 236                 switch (cmd) {
 237                 case RIPCMD_REQUEST:
 238                 case RIPCMD_RESPONSE:
 239                         j = length / sizeof(*ni);
 240                         ND_PRINT(", routes: %u%s", j, vers == 2 ? " or less" : "");
 241                         ni = (const struct rip_netinfo *)(rp + 1);
 242                         for (; i >= sizeof(*ni); ++ni) {
 243                                 if (vers == 1)
 244                                 {
 245                                         rip_entry_print_v1(ndo, ni);
 246                                         i -= sizeof(*ni);
 247                                 }
 248                                 else if (vers == 2)
 249                                         i -= rip_entry_print_v2(ndo, ni, i);
 250                                 else
 251                                     break;
 252                         }
 253                         if (i)
 254                                 ND_PRINT("%s", tstr);
 255                         break;
 256
 257                 case RIPCMD_TRACEOFF:
 258                 case RIPCMD_POLL:
 259                 case RIPCMD_POLLENTRY:
 260                         break;
 261
 262                 case RIPCMD_TRACEON:
 263                     /* fall through */
 264                 default:
 265                     if (ndo->ndo_vflag <= 1) {
 266                         if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
 267                             return;
 268                     }
 269                     break;
 270                 }
 271                 /* do we want to see an additionally hexdump ? */
 272                 if (ndo->ndo_vflag> 1) {
 273                     if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
 274                         return;
 275                 }
 276         }
 277 }
 278
 279