The Tcpdump Group git mirrors - tcpdump/blob - print-dvmrp.c

   1 /*
   2  * Copyright (c) 1995, 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 #ifndef lint
  23 static const char rcsid[] =
  24     "@(#) $Header: /tcpdump/master/tcpdump/print-dvmrp.c,v 1.20 2000-09-29 04:58:36 guy Exp $ (LBL)";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <sys/param.h>
  32 #include <sys/time.h>
  33 #include <sys/socket.h>
  34
  35 #include <netinet/in.h>
  36
  37 #include <stdio.h>
  38 #include <string.h>
  39 #include <stdlib.h>
  40 #include <unistd.h>
  41
  42 #include "interface.h"
  43 #include "extract.h"
  44 #include "addrtoname.h"
  45
  46 /*
  47  * DVMRP message types and flag values shamelessly stolen from
  48  * mrouted/dvmrp.h.
  49  */
  50 #define DVMRP_PROBE             1       /* for finding neighbors */
  51 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  52 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  53                                         /*
  54                                          * of this router's neighbors
  55                                          */
  56 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  57 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  58 #define DVMRP_NEIGHBORS2        6
  59 #define DVMRP_PRUNE             7       /* prune message */
  60 #define DVMRP_GRAFT             8       /* graft message */
  61 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  62
  63 /*
  64  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  65  */
  66 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  67 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  68 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  69 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  70 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  71
  72 static void print_probe(const u_char *, const u_char *, u_int);
  73 static void print_report(const u_char *, const u_char *, u_int);
  74 static void print_neighbors(const u_char *, const u_char *, u_int);
  75 static void print_neighbors2(const u_char *, const u_char *, u_int);
  76 static void print_prune(const u_char *, const u_char *, u_int);
  77 static void print_graft(const u_char *, const u_char *, u_int);
  78 static void print_graft_ack(const u_char *, const u_char *, u_int);
  79
  80 static u_int32_t target_level;
  81
  82 void
  83 dvmrp_print(register const u_char *bp, register u_int len)
  84 {
  85         register const u_char *ep;
  86         register u_char type;
  87
  88         ep = (const u_char *)snapend;
  89         if (bp >= ep)
  90                 return;
  91
  92         type = bp[1];
  93         bp += 8;
  94         /*
  95          * Skip IGMP header
  96          */
  97
  98         len -= 8;
  99
 100         switch (type) {
 101
 102         case DVMRP_PROBE:
 103                 printf(" Probe");
 104                 if (vflag)
 105                         print_probe(bp, ep, len);
 106                 break;
 107
 108         case DVMRP_REPORT:
 109                 printf(" Report");
 110                 if (vflag)
 111                         print_report(bp, ep, len);
 112                 break;
 113
 114         case DVMRP_ASK_NEIGHBORS:
 115                 printf(" Ask-neighbors(old)");
 116                 break;
 117
 118         case DVMRP_NEIGHBORS:
 119                 printf(" Neighbors(old)");
 120                 print_neighbors(bp, ep, len);
 121                 break;
 122
 123         case DVMRP_ASK_NEIGHBORS2:
 124                 printf(" Ask-neighbors2");
 125                 break;
 126
 127         case DVMRP_NEIGHBORS2:
 128                 printf(" Neighbors2");
 129                 /*
 130                  * extract version and capabilities from IGMP group
 131                  * address field
 132                  */
 133                 bp -= 4;
 134                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 135                     (bp[2] << 8) | bp[3];
 136                 bp += 4;
 137                 print_neighbors2(bp, ep, len);
 138                 break;
 139
 140         case DVMRP_PRUNE:
 141                 printf(" Prune");
 142                 print_prune(bp, ep, len);
 143                 break;
 144
 145         case DVMRP_GRAFT:
 146                 printf(" Graft");
 147                 print_graft(bp, ep, len);
 148                 break;
 149
 150         case DVMRP_GRAFT_ACK:
 151                 printf(" Graft-ACK");
 152                 print_graft_ack(bp, ep, len);
 153                 break;
 154
 155         default:
 156                 printf(" [type %d]", type);
 157                 break;
 158         }
 159 }
 160
 161 static void
 162 print_report(register const u_char *bp, register const u_char *ep,
 163     register u_int len)
 164 {
 165         register u_int32_t mask, origin;
 166         register int metric, i, width, done;
 167
 168         while (len > 0) {
 169                 if (len < 3) {
 170                         printf(" [|]");
 171                         return;
 172                 }
 173                 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 174                 width = 1;
 175                 if (bp[0])
 176                         width = 2;
 177                 if (bp[1])
 178                         width = 3;
 179                 if (bp[2])
 180                         width = 4;
 181
 182                 printf("\n\tMask %s", intoa(htonl(mask)));
 183                 bp += 3;
 184                 len -= 3;
 185                 do {
 186                         if (bp + width + 1 > ep) {
 187                                 printf(" [|]");
 188                                 return;
 189                         }
 190                         if (len < width + 1) {
 191                                 printf("\n\t  [Truncated Report]");
 192                                 return;
 193                         }
 194                         origin = 0;
 195                         for (i = 0; i < width; ++i)
 196                                 origin = origin << 8 | *bp++;
 197                         for ( ; i < 4; ++i)
 198                                 origin <<= 8;
 199
 200                         metric = *bp++;
 201                         done = metric & 0x80;
 202                         metric &= 0x7f;
 203                         printf("\n\t  %s metric %d", intoa(htonl(origin)),
 204                                 metric);
 205                         len -= width + 1;
 206                 } while (!done);
 207         }
 208 }
 209
 210 static void
 211 print_probe(register const u_char *bp, register const u_char *ep,
 212     register u_int len)
 213 {
 214         register u_int32_t genid;
 215
 216         TCHECK2(bp[0], 4);
 217         if ((len < 4) || ((bp + 4) > ep)) {
 218                 /* { (ctags) */
 219                 printf(" [|}");
 220                 return;
 221         }
 222         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 223         bp += 4;
 224         len -= 4;
 225         printf("\n\tgenid %u", genid);
 226
 227         while ((len > 0) && (bp < ep)) {
 228                 TCHECK2(bp[0], 4);
 229                 printf("\n\tneighbor %s", ipaddr_string(bp));
 230                 bp += 4; len -= 4;
 231         }
 232         return;
 233 trunc:
 234         (void)printf("[|dvmrp]");
 235 }
 236
 237 static void
 238 print_neighbors(register const u_char *bp, register const u_char *ep,
 239     register u_int len)
 240 {
 241         const u_char *laddr;
 242         register u_char metric;
 243         register u_char thresh;
 244         register int ncount;
 245
 246         while (len > 0 && bp < ep) {
 247                 TCHECK2(bp[0], 7);
 248                 laddr = bp;
 249                 bp += 4;
 250                 metric = *bp++;
 251                 thresh = *bp++;
 252                 ncount = *bp++;
 253                 len -= 7;
 254                 while (--ncount >= 0) {
 255                         TCHECK2(bp[0], 4);
 256                         printf(" [%s ->", ipaddr_string(laddr));
 257                         printf(" %s, (%d/%d)]",
 258                                    ipaddr_string(bp), metric, thresh);
 259                         bp += 4;
 260                         len -= 4;
 261                 }
 262         }
 263         return;
 264 trunc:
 265         (void)printf("[|dvmrp]");
 266 }
 267
 268 static void
 269 print_neighbors2(register const u_char *bp, register const u_char *ep,
 270     register u_int len)
 271 {
 272         const u_char *laddr;
 273         register u_char metric, thresh, flags;
 274         register int ncount;
 275
 276         printf(" (v %d.%d):",
 277                (int)target_level & 0xff,
 278                (int)(target_level >> 8) & 0xff);
 279
 280         while (len > 0 && bp < ep) {
 281                 TCHECK2(bp[0], 8);
 282                 laddr = bp;
 283                 bp += 4;
 284                 metric = *bp++;
 285                 thresh = *bp++;
 286                 flags = *bp++;
 287                 ncount = *bp++;
 288                 len -= 8;
 289                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 290                         printf(" [%s -> ", ipaddr_string(laddr));
 291                         printf("%s (%d/%d", ipaddr_string(bp),
 292                                      metric, thresh);
 293                         if (flags & DVMRP_NF_TUNNEL)
 294                                 printf("/tunnel");
 295                         if (flags & DVMRP_NF_SRCRT)
 296                                 printf("/srcrt");
 297                         if (flags & DVMRP_NF_QUERIER)
 298                                 printf("/querier");
 299                         if (flags & DVMRP_NF_DISABLED)
 300                                 printf("/disabled");
 301                         if (flags & DVMRP_NF_DOWN)
 302                                 printf("/down");
 303                         printf(")]");
 304                         bp += 4;
 305                         len -= 4;
 306                 }
 307                 if (ncount != -1) {
 308                         printf(" [|]");
 309                         return;
 310                 }
 311         }
 312         return;
 313 trunc:
 314         (void)printf("[|dvmrp]");
 315 }
 316
 317 static void
 318 print_prune(register const u_char *bp, register const u_char *ep,
 319     register u_int len)
 320 {
 321         TCHECK2(bp[0], 12);
 322         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 323         bp += 8;
 324         (void)printf(" timer ");
 325         relts_print(EXTRACT_32BITS(bp));
 326         return;
 327 trunc:
 328         (void)printf("[|dvmrp]");
 329 }
 330
 331 static void
 332 print_graft(register const u_char *bp, register const u_char *ep,
 333     register u_int len)
 334 {
 335         TCHECK2(bp[0], 8);
 336         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 337         return;
 338 trunc:
 339         (void)printf("[|dvmrp]");
 340 }
 341
 342 static void
 343 print_graft_ack(register const u_char *bp, register const u_char *ep,
 344     register u_int len)
 345 {
 346         TCHECK2(bp[0], 8);
 347         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 348         return;
 349 trunc:
 350         (void)printf("[|dvmrp]");
 351 }