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