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 1.16 1999-11-21 09:36:51 fenner 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 #include <netinet/in_systm.h>
  37 #include <netinet/ip.h>
  38 #include <netinet/ip_var.h>
  39 #include <netinet/udp.h>
  40 #include <netinet/udp_var.h>
  41 #include <netinet/tcp.h>
  42
  43 #include <stdio.h>
  44 #include <string.h>
  45 #include <stdlib.h>
  46 #include <unistd.h>
  47
  48 #include "interface.h"
  49 #include "addrtoname.h"
  50
  51 /*
  52  * DVMRP message types and flag values shamelessly stolen from
  53  * mrouted/dvmrp.h.
  54  */
  55 #define DVMRP_PROBE             1       /* for finding neighbors */
  56 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  57 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  58                                         /*
  59                                          * of this router's neighbors
  60                                          */
  61 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  62 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  63 #define DVMRP_NEIGHBORS2        6
  64 #define DVMRP_PRUNE             7       /* prune message */
  65 #define DVMRP_GRAFT             8       /* graft message */
  66 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  67
  68 /*
  69  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  70  */
  71 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  72 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  73 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  74 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  75 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  76
  77 static void print_probe(const u_char *, const u_char *, u_int);
  78 static void print_report(const u_char *, const u_char *, u_int);
  79 static void print_neighbors(const u_char *, const u_char *, u_int);
  80 static void print_neighbors2(const u_char *, const u_char *, u_int);
  81 static void print_prune(const u_char *, const u_char *, u_int);
  82 static void print_graft(const u_char *, const u_char *, u_int);
  83 static void print_graft_ack(const u_char *, const u_char *, u_int);
  84
  85 static u_int32_t target_level;
  86
  87 void
  88 dvmrp_print(register const u_char *bp, register u_int len)
  89 {
  90         register const u_char *ep;
  91         register u_char type;
  92
  93         ep = (const u_char *)snapend;
  94         if (bp >= ep)
  95                 return;
  96
  97         type = bp[1];
  98         bp += 8;
  99         /*
 100          * Skip IGMP header
 101          */
 102
 103         len -= 8;
 104
 105         switch (type) {
 106
 107         case DVMRP_PROBE:
 108                 printf(" Probe");
 109                 if (vflag)
 110                         print_probe(bp, ep, len);
 111                 break;
 112
 113         case DVMRP_REPORT:
 114                 printf(" Report");
 115                 if (vflag)
 116                         print_report(bp, ep, len);
 117                 break;
 118
 119         case DVMRP_ASK_NEIGHBORS:
 120                 printf(" Ask-neighbors(old)");
 121                 break;
 122
 123         case DVMRP_NEIGHBORS:
 124                 printf(" Neighbors(old)");
 125                 print_neighbors(bp, ep, len);
 126                 break;
 127
 128         case DVMRP_ASK_NEIGHBORS2:
 129                 printf(" Ask-neighbors2");
 130                 break;
 131
 132         case DVMRP_NEIGHBORS2:
 133                 printf(" Neighbors2");
 134                 /*
 135                  * extract version and capabilities from IGMP group
 136                  * address field
 137                  */
 138                 bp -= 4;
 139                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 140                     (bp[2] << 8) | bp[3];
 141                 bp += 4;
 142                 print_neighbors2(bp, ep, len);
 143                 break;
 144
 145         case DVMRP_PRUNE:
 146                 printf(" Prune");
 147                 print_prune(bp, ep, len);
 148                 break;
 149
 150         case DVMRP_GRAFT:
 151                 printf(" Graft");
 152                 print_graft(bp, ep, len);
 153                 break;
 154
 155         case DVMRP_GRAFT_ACK:
 156                 printf(" Graft-ACK");
 157                 print_graft_ack(bp, ep, len);
 158                 break;
 159
 160         default:
 161                 printf(" [type %d]", type);
 162                 break;
 163         }
 164 }
 165
 166 static void
 167 print_report(register const u_char *bp, register const u_char *ep,
 168     register u_int len)
 169 {
 170         register u_int32_t mask, origin;
 171         register int metric, i, width, done;
 172
 173         while (len > 0) {
 174                 if (len < 3) {
 175                         printf(" [|]");
 176                         return;
 177                 }
 178                 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 179                 width = 1;
 180                 if (bp[0])
 181                         width = 2;
 182                 if (bp[1])
 183                         width = 3;
 184                 if (bp[2])
 185                         width = 4;
 186
 187                 printf("\n\tMask %s", intoa(htonl(mask)));
 188                 bp += 3;
 189                 len -= 3;
 190                 do {
 191                         if (bp + width + 1 > ep) {
 192                                 printf(" [|]");
 193                                 return;
 194                         }
 195                         if (len < width + 1) {
 196                                 printf("\n\t  [Truncated Report]");
 197                                 return;
 198                         }
 199                         origin = 0;
 200                         for (i = 0; i < width; ++i)
 201                                 origin = origin << 8 | *bp++;
 202                         for ( ; i < 4; ++i)
 203                                 origin <<= 8;
 204
 205                         metric = *bp++;
 206                         done = metric & 0x80;
 207                         metric &= 0x7f;
 208                         printf("\n\t  %s metric %d", intoa(htonl(origin)),
 209                                 metric);
 210                         len -= width + 1;
 211                 } while (!done);
 212         }
 213 }
 214
 215 #define GET_ADDR(to) (memcpy((char *)to, (char *)bp, 4), bp += 4)
 216
 217 static void
 218 print_probe(register const u_char *bp, register const u_char *ep,
 219     register u_int len)
 220 {
 221         register u_int32_t genid;
 222         u_char neighbor[4];
 223
 224         if ((len < 4) || ((bp + 4) > ep)) {
 225                 /* { (ctags) */
 226                 printf(" [|}");
 227                 return;
 228         }
 229         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 230         bp += 4;
 231         len -= 4;
 232         printf("\n\tgenid %u", genid);
 233
 234         while ((len > 0) && (bp < ep)) {
 235                 if ((len < 4) || ((bp + 4) > ep)) {
 236                         printf(" [|]");
 237                         return;
 238                 }
 239                 GET_ADDR(neighbor);
 240                 len -= 4;
 241                 printf("\n\tneighbor %s", ipaddr_string(neighbor));
 242         }
 243 }
 244
 245 static void
 246 print_neighbors(register const u_char *bp, register const u_char *ep,
 247     register u_int len)
 248 {
 249         u_char laddr[4], neighbor[4];
 250         register u_char metric;
 251         register u_char thresh;
 252         register int ncount;
 253
 254         while (len > 0 && bp < ep) {
 255                 if (len < 7 || (bp + 7) >= ep) {
 256                         printf(" [|]");
 257                         return;
 258                 }
 259                 GET_ADDR(laddr);
 260                 metric = *bp++;
 261                 thresh = *bp++;
 262                 ncount = *bp++;
 263                 len -= 7;
 264                 while (--ncount >= 0 && (len >= 4) && (bp + 4) < ep) {
 265                         GET_ADDR(neighbor);
 266                         printf(" [%s ->", ipaddr_string(laddr));
 267                         printf(" %s, (%d/%d)]",
 268                                    ipaddr_string(neighbor), metric, thresh);
 269                         len -= 4;
 270                 }
 271         }
 272 }
 273
 274 static void
 275 print_neighbors2(register const u_char *bp, register const u_char *ep,
 276     register u_int len)
 277 {
 278         u_char laddr[4], neighbor[4];
 279         register u_char metric, thresh, flags;
 280         register int ncount;
 281
 282         printf(" (v %d.%d):",
 283                (int)target_level & 0xff,
 284                (int)(target_level >> 8) & 0xff);
 285
 286         while (len > 0 && bp < ep) {
 287                 if (len < 8 || (bp + 8) >= ep) {
 288                         printf(" [|]");
 289                         return;
 290                 }
 291                 GET_ADDR(laddr);
 292                 metric = *bp++;
 293                 thresh = *bp++;
 294                 flags = *bp++;
 295                 ncount = *bp++;
 296                 len -= 8;
 297                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 298                         GET_ADDR(neighbor);
 299                         printf(" [%s -> ", ipaddr_string(laddr));
 300                         printf("%s (%d/%d", ipaddr_string(neighbor),
 301                                      metric, thresh);
 302                         if (flags & DVMRP_NF_TUNNEL)
 303                                 printf("/tunnel");
 304                         if (flags & DVMRP_NF_SRCRT)
 305                                 printf("/srcrt");
 306                         if (flags & DVMRP_NF_QUERIER)
 307                                 printf("/querier");
 308                         if (flags & DVMRP_NF_DISABLED)
 309                                 printf("/disabled");
 310                         if (flags & DVMRP_NF_DOWN)
 311                                 printf("/down");
 312                         printf(")]");
 313                         len -= 4;
 314                 }
 315                 if (ncount != -1) {
 316                         printf(" [|]");
 317                         return;
 318                 }
 319         }
 320 }
 321
 322 static void
 323 print_prune(register const u_char *bp, register const u_char *ep,
 324     register u_int len)
 325 {
 326         union a {
 327                 u_char b[4];
 328                 u_int32_t i;
 329         } prune_timer;
 330
 331         if (len < 12 || (bp + 12) > ep) {
 332                 printf(" [|]");
 333                 return;
 334         }
 335         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 336         bp += 8;
 337         GET_ADDR(prune_timer.b);
 338         printf(" timer %d", (int)ntohl(prune_timer.i));
 339 }
 340
 341 static void
 342 print_graft(register const u_char *bp, register const u_char *ep,
 343     register u_int len)
 344 {
 345
 346         if (len < 8 || (bp + 8) > ep) {
 347                 printf(" [|]");
 348                 return;
 349         }
 350         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 351 }
 352
 353 static void
 354 print_graft_ack(register const u_char *bp, register const u_char *ep,
 355     register u_int len)
 356 {
 357
 358         if (len < 8 || (bp + 8) > ep) {
 359                 printf(" [|]");
 360                 return;
 361         }
 362         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 363 }