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 #ifdef HAVE_CONFIG_H
  25 #include "config.h"
  26 #endif
  27
  28 #include <netdissect-stdinc.h>
  29
  30 #include <stdio.h>
  31
  32 #include "netdissect.h"
  33 #include "addrtoname.h"
  34 #include "extract.h"
  35
  36 #include "af.h"
  37
  38 static const char tstr[] = "[|rip]";
  39
  40 struct rip {
  41         uint8_t rip_cmd;                /* request/response */
  42         uint8_t rip_vers;               /* protocol version # */
  43         uint8_t unused[2];              /* unused */
  44 };
  45
  46 #define RIPCMD_REQUEST          1       /* want info */
  47 #define RIPCMD_RESPONSE         2       /* responding to request */
  48 #define RIPCMD_TRACEON          3       /* turn tracing on */
  49 #define RIPCMD_TRACEOFF         4       /* turn it off */
  50 #define RIPCMD_POLL             5       /* want info from everybody */
  51 #define RIPCMD_POLLENTRY        6       /* poll for entry */
  52
  53 static const struct tok rip_cmd_values[] = {
  54     { RIPCMD_REQUEST,           "Request" },
  55     { RIPCMD_RESPONSE,          "Response" },
  56     { RIPCMD_TRACEON,           "Trace on" },
  57     { RIPCMD_TRACEOFF,          "Trace off" },
  58     { RIPCMD_POLL,              "Poll" },
  59     { RIPCMD_POLLENTRY,         "Poll Entry" },
  60     { 0, NULL}
  61 };
  62
  63 #define RIP_AUTHLEN  16
  64 #define RIP_ROUTELEN 20
  65
  66 /*
  67  * rfc 1723
  68  *
  69  *  0                   1                   2                   3 3
  70  *  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
  71  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  72  * | Command (1)   | Version (1)   |           unused              |
  73  * +---------------+---------------+-------------------------------+
  74  * | Address Family Identifier (2) |        Route Tag (2)          |
  75  * +-------------------------------+-------------------------------+
  76  * |                         IP Address (4)                        |
  77  * +---------------------------------------------------------------+
  78  * |                         Subnet Mask (4)                       |
  79  * +---------------------------------------------------------------+
  80  * |                         Next Hop (4)                          |
  81  * +---------------------------------------------------------------+
  82  * |                         Metric (4)                            |
  83  * +---------------------------------------------------------------+
  84  *
  85  */
  86
  87 struct rip_netinfo {
  88         uint16_t rip_family;
  89         uint16_t rip_tag;
  90         uint32_t rip_dest;
  91         uint32_t rip_dest_mask;
  92         uint32_t rip_router;
  93         uint32_t rip_metric;            /* cost of route */
  94 };
  95
  96 static void
  97 rip_entry_print_v1(netdissect_options *ndo,
  98                    register const struct rip_netinfo *ni)
  99 {
 100         register u_short family;
 101
 102         /* RFC 1058 */
 103         family = EXTRACT_16BITS(&ni->rip_family);
 104         if (family != BSD_AFNUM_INET && family != 0) {
 105                 ND_PRINT((ndo, "\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family)));
 106                 print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
 107                 return;
 108         }
 109         if (EXTRACT_16BITS(&ni->rip_tag) ||
 110             EXTRACT_32BITS(&ni->rip_dest_mask) ||
 111             EXTRACT_32BITS(&ni->rip_router)) {
 112                 /* MBZ fields not zero */
 113                 print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
 114                 return;
 115         }
 116         if (family == 0) {
 117                 ND_PRINT((ndo, "\n\t  AFI 0, %s, metric: %u",
 118                         ipaddr_string(ndo, &ni->rip_dest),
 119                         EXTRACT_32BITS(&ni->rip_metric)));
 120                 return;
 121         } /* BSD_AFNUM_INET */
 122         ND_PRINT((ndo, "\n\t  %s, metric: %u",
 123                ipaddr_string(ndo, &ni->rip_dest),
 124                EXTRACT_32BITS(&ni->rip_metric)));
 125 }
 126
 127 static unsigned
 128 rip_entry_print_v2(netdissect_options *ndo,
 129                    register const struct rip_netinfo *ni, const unsigned remaining)
 130 {
 131         register u_short family;
 132
 133         family = EXTRACT_16BITS(&ni->rip_family);
 134         if (family == 0xFFFF) { /* variable-sized authentication structures */
 135                 uint16_t auth_type = EXTRACT_16BITS(&ni->rip_tag);
 136                 if (auth_type == 2) {
 137                         register const u_char *p = (const u_char *)&ni->rip_dest;
 138                         u_int i = 0;
 139                         ND_PRINT((ndo, "\n\t  Simple Text Authentication data: "));
 140                         for (; i < RIP_AUTHLEN; p++, i++)
 141                                 ND_PRINT((ndo, "%c", ND_ISPRINT(*p) ? *p : '.'));
 142                 } else if (auth_type == 3) {
 143                         ND_PRINT((ndo, "\n\t  Auth header:"));
 144                         ND_PRINT((ndo, " Packet Len %u,", EXTRACT_16BITS((const uint8_t *)ni + 4)));
 145                         ND_PRINT((ndo, " Key-ID %u,", *((const uint8_t *)ni + 6)));
 146                         ND_PRINT((ndo, " Auth Data Len %u,", *((const uint8_t *)ni + 7)));
 147                         ND_PRINT((ndo, " SeqNo %u,", EXTRACT_32BITS(&ni->rip_dest_mask)));
 148                         ND_PRINT((ndo, " MBZ %u,", EXTRACT_32BITS(&ni->rip_router)));
 149                         ND_PRINT((ndo, " MBZ %u", EXTRACT_32BITS(&ni->rip_metric)));
 150                 } else if (auth_type == 1) {
 151                         ND_PRINT((ndo, "\n\t  Auth trailer:"));
 152                         print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
 153                         return remaining; /* AT spans till the packet end */
 154                 } else {
 155                         ND_PRINT((ndo, "\n\t  Unknown (%u) Authentication data:",
 156                                EXTRACT_16BITS(&ni->rip_tag)));
 157                         print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
 158                 }
 159         } else if (family != BSD_AFNUM_INET && family != 0) {
 160                 ND_PRINT((ndo, "\n\t  AFI %s", tok2str(bsd_af_values, "Unknown (%u)", family)));
 161                 print_unknown_data(ndo, (const uint8_t *)&ni->rip_tag, "\n\t  ", RIP_ROUTELEN-2);
 162         } else { /* BSD_AFNUM_INET or AFI 0 */
 163                 ND_PRINT((ndo, "\n\t  AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
 164                        tok2str(bsd_af_values, "%u", family),
 165                        ipaddr_string(ndo, &ni->rip_dest),
 166                        mask2plen(EXTRACT_32BITS(&ni->rip_dest_mask)),
 167                        EXTRACT_16BITS(&ni->rip_tag),
 168                        EXTRACT_32BITS(&ni->rip_metric)));
 169                 if (EXTRACT_32BITS(&ni->rip_router))
 170                         ND_PRINT((ndo, "%s", ipaddr_string(ndo, &ni->rip_router)));
 171                 else
 172                         ND_PRINT((ndo, "self"));
 173         }
 174         return sizeof (*ni);
 175 }
 176
 177 void
 178 rip_print(netdissect_options *ndo,
 179           const u_char *dat, u_int length)
 180 {
 181         register const struct rip *rp;
 182         register const struct rip_netinfo *ni;
 183         register u_int i, j;
 184
 185         if (ndo->ndo_snapend < dat) {
 186                 ND_PRINT((ndo, " %s", tstr));
 187                 return;
 188         }
 189         i = ndo->ndo_snapend - dat;
 190         if (i > length)
 191                 i = length;
 192         if (i < sizeof(*rp)) {
 193                 ND_PRINT((ndo, " %s", tstr));
 194                 return;
 195         }
 196         i -= sizeof(*rp);
 197
 198         rp = (const struct rip *)dat;
 199
 200         ND_PRINT((ndo, "%sRIPv%u",
 201                (ndo->ndo_vflag >= 1) ? "\n\t" : "",
 202                rp->rip_vers));
 203
 204         switch (rp->rip_vers) {
 205         case 0:
 206                 /*
 207                  * RFC 1058.
 208                  *
 209                  * XXX - RFC 1058 says
 210                  *
 211                  * 0  Datagrams whose version number is zero are to be ignored.
 212                  *    These are from a previous version of the protocol, whose
 213                  *    packet format was machine-specific.
 214                  *
 215                  * so perhaps we should just dump the packet, in hex.
 216                  */
 217                 print_unknown_data(ndo, (const uint8_t *)&rp->rip_cmd, "\n\t", length);
 218                 break;
 219         default:
 220                 /* dump version and lets see if we know the commands name*/
 221                 ND_PRINT((ndo, ", %s, length: %u",
 222                        tok2str(rip_cmd_values,
 223                                "unknown command (%u)",
 224                                rp->rip_cmd),
 225                        length));
 226
 227                 if (ndo->ndo_vflag < 1)
 228                     return;
 229
 230                 switch (rp->rip_cmd) {
 231                 case RIPCMD_REQUEST:
 232                 case RIPCMD_RESPONSE:
 233                         j = length / sizeof(*ni);
 234                         ND_PRINT((ndo, ", routes: %u%s", j, rp->rip_vers == 2 ? " or less" : ""));
 235                         ni = (const struct rip_netinfo *)(rp + 1);
 236                         for (; i >= sizeof(*ni); ++ni) {
 237                                 if (rp->rip_vers == 1)
 238                                 {
 239                                         rip_entry_print_v1(ndo, ni);
 240                                         i -= sizeof(*ni);
 241                                 }
 242                                 else if (rp->rip_vers == 2)
 243                                         i -= rip_entry_print_v2(ndo, ni, i);
 244                                 else
 245                                     break;
 246                         }
 247                         if (i)
 248                                 ND_PRINT((ndo, "%s", tstr));
 249                         break;
 250
 251                 case RIPCMD_TRACEOFF:
 252                 case RIPCMD_POLL:
 253                 case RIPCMD_POLLENTRY:
 254                         break;
 255
 256                 case RIPCMD_TRACEON:
 257                     /* fall through */
 258                 default:
 259                     if (ndo->ndo_vflag <= 1) {
 260                         if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
 261                             return;
 262                     }
 263                     break;
 264                 }
 265                 /* do we want to see an additionally hexdump ? */
 266                 if (ndo->ndo_vflag> 1) {
 267                     if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
 268                         return;
 269                 }
 270         }
 271 }
 272
 273