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