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 1.15 1999-10-30 05:11:12 itojun Exp $ (LBL)";
  25 #endif
  26
  27 #include <sys/param.h>
  28 #include <sys/time.h>
  29 #include <sys/socket.h>
  30
  31 #include <netinet/in.h>
  32 #include <netinet/in_systm.h>
  33 #include <netinet/ip.h>
  34 #include <netinet/ip_var.h>
  35 #include <netinet/udp.h>
  36 #include <netinet/udp_var.h>
  37 #include <netinet/tcp.h>
  38
  39 #include <stdio.h>
  40 #include <string.h>
  41 #include <stdlib.h>
  42 #include <unistd.h>
  43
  44 #include "interface.h"
  45 #include "addrtoname.h"
  46
  47 /*
  48  * DVMRP message types and flag values shamelessly stolen from
  49  * mrouted/dvmrp.h.
  50  */
  51 #define DVMRP_PROBE             1       /* for finding neighbors */
  52 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  53 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  54                                         /*
  55                                          * of this router's neighbors
  56                                          */
  57 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  58 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  59 #define DVMRP_NEIGHBORS2        6
  60 #define DVMRP_PRUNE             7       /* prune message */
  61 #define DVMRP_GRAFT             8       /* graft message */
  62 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  63
  64 /*
  65  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  66  */
  67 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  68 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  69 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  70 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  71 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  72
  73 static void print_probe(const u_char *, const u_char *, u_int);
  74 static void print_report(const u_char *, const u_char *, u_int);
  75 static void print_neighbors(const u_char *, const u_char *, u_int);
  76 static void print_neighbors2(const u_char *, const u_char *, u_int);
  77 static void print_prune(const u_char *, const u_char *, u_int);
  78 static void print_graft(const u_char *, const u_char *, u_int);
  79 static void print_graft_ack(const u_char *, const u_char *, u_int);
  80
  81 static u_int32_t target_level;
  82
  83 void
  84 dvmrp_print(register const u_char *bp, register u_int len)
  85 {
  86         register const u_char *ep;
  87         register u_char type;
  88
  89         ep = (const u_char *)snapend;
  90         if (bp >= ep)
  91                 return;
  92
  93         type = bp[1];
  94         bp += 8;
  95         /*
  96          * Skip IGMP header
  97          */
  98
  99         len -= 8;
 100
 101         switch (type) {
 102
 103         case DVMRP_PROBE:
 104                 printf(" Probe");
 105                 if (vflag)
 106                         print_probe(bp, ep, len);
 107                 break;
 108
 109         case DVMRP_REPORT:
 110                 printf(" Report");
 111                 if (vflag)
 112                         print_report(bp, ep, len);
 113                 break;
 114
 115         case DVMRP_ASK_NEIGHBORS:
 116                 printf(" Ask-neighbors(old)");
 117                 break;
 118
 119         case DVMRP_NEIGHBORS:
 120                 printf(" Neighbors(old)");
 121                 print_neighbors(bp, ep, len);
 122                 break;
 123
 124         case DVMRP_ASK_NEIGHBORS2:
 125                 printf(" Ask-neighbors2");
 126                 break;
 127
 128         case DVMRP_NEIGHBORS2:
 129                 printf(" Neighbors2");
 130                 /*
 131                  * extract version and capabilities from IGMP group
 132                  * address field
 133                  */
 134                 bp -= 4;
 135                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 136                     (bp[2] << 8) | bp[3];
 137                 bp += 4;
 138                 print_neighbors2(bp, ep, len);
 139                 break;
 140
 141         case DVMRP_PRUNE:
 142                 printf(" Prune");
 143                 print_prune(bp, ep, len);
 144                 break;
 145
 146         case DVMRP_GRAFT:
 147                 printf(" Graft");
 148                 print_graft(bp, ep, len);
 149                 break;
 150
 151         case DVMRP_GRAFT_ACK:
 152                 printf(" Graft-ACK");
 153                 print_graft_ack(bp, ep, len);
 154                 break;
 155
 156         default:
 157                 printf(" [type %d]", type);
 158                 break;
 159         }
 160 }
 161
 162 static void
 163 print_report(register const u_char *bp, register const u_char *ep,
 164     register u_int len)
 165 {
 166         register u_int32_t mask, origin;
 167         register int metric, i, width, done;
 168
 169         while (len > 0) {
 170                 if (len < 3) {
 171                         printf(" [|]");
 172                         return;
 173                 }
 174                 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 175                 width = 1;
 176                 if (bp[0])
 177                         width = 2;
 178                 if (bp[1])
 179                         width = 3;
 180                 if (bp[2])
 181                         width = 4;
 182
 183                 printf("\n\tMask %s", intoa(htonl(mask)));
 184                 bp += 3;
 185                 len -= 3;
 186                 do {
 187                         if (bp + width + 1 > ep) {
 188                                 printf(" [|]");
 189                                 return;
 190                         }
 191                         if (len < width + 1) {
 192                                 printf("\n\t  [Truncated Report]");
 193                                 return;
 194                         }
 195                         origin = 0;
 196                         for (i = 0; i < width; ++i)
 197                                 origin = origin << 8 | *bp++;
 198                         for ( ; i < 4; ++i)
 199                                 origin <<= 8;
 200
 201                         metric = *bp++;
 202                         done = metric & 0x80;
 203                         metric &= 0x7f;
 204                         printf("\n\t  %s metric %d", intoa(htonl(origin)),
 205                                 metric);
 206                         len -= width + 1;
 207                 } while (!done);
 208         }
 209 }
 210
 211 #define GET_ADDR(to) (memcpy((char *)to, (char *)bp, 4), bp += 4)
 212
 213 static void
 214 print_probe(register const u_char *bp, register const u_char *ep,
 215     register u_int len)
 216 {
 217         register u_int32_t genid;
 218         u_char neighbor[4];
 219
 220         if ((len < 4) || ((bp + 4) > ep)) {
 221                 /* { (ctags) */
 222                 printf(" [|}");
 223                 return;
 224         }
 225         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 226         bp += 4;
 227         len -= 4;
 228         printf("\n\tgenid %u", genid);
 229
 230         while ((len > 0) && (bp < ep)) {
 231                 if ((len < 4) || ((bp + 4) > ep)) {
 232                         printf(" [|]");
 233                         return;
 234                 }
 235                 GET_ADDR(neighbor);
 236                 len -= 4;
 237                 printf("\n\tneighbor %s", ipaddr_string(neighbor));
 238         }
 239 }
 240
 241 static void
 242 print_neighbors(register const u_char *bp, register const u_char *ep,
 243     register u_int len)
 244 {
 245         u_char laddr[4], neighbor[4];
 246         register u_char metric;
 247         register u_char thresh;
 248         register int ncount;
 249
 250         while (len > 0 && bp < ep) {
 251                 if (len < 7 || (bp + 7) >= ep) {
 252                         printf(" [|]");
 253                         return;
 254                 }
 255                 GET_ADDR(laddr);
 256                 metric = *bp++;
 257                 thresh = *bp++;
 258                 ncount = *bp++;
 259                 len -= 7;
 260                 while (--ncount >= 0 && (len >= 4) && (bp + 4) < ep) {
 261                         GET_ADDR(neighbor);
 262                         printf(" [%s ->", ipaddr_string(laddr));
 263                         printf(" %s, (%d/%d)]",
 264                                    ipaddr_string(neighbor), metric, thresh);
 265                         len -= 4;
 266                 }
 267         }
 268 }
 269
 270 static void
 271 print_neighbors2(register const u_char *bp, register const u_char *ep,
 272     register u_int len)
 273 {
 274         u_char laddr[4], neighbor[4];
 275         register u_char metric, thresh, flags;
 276         register int ncount;
 277
 278         printf(" (v %d.%d):",
 279                (int)target_level & 0xff,
 280                (int)(target_level >> 8) & 0xff);
 281
 282         while (len > 0 && bp < ep) {
 283                 if (len < 8 || (bp + 8) >= ep) {
 284                         printf(" [|]");
 285                         return;
 286                 }
 287                 GET_ADDR(laddr);
 288                 metric = *bp++;
 289                 thresh = *bp++;
 290                 flags = *bp++;
 291                 ncount = *bp++;
 292                 len -= 8;
 293                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 294                         GET_ADDR(neighbor);
 295                         printf(" [%s -> ", ipaddr_string(laddr));
 296                         printf("%s (%d/%d", ipaddr_string(neighbor),
 297                                      metric, thresh);
 298                         if (flags & DVMRP_NF_TUNNEL)
 299                                 printf("/tunnel");
 300                         if (flags & DVMRP_NF_SRCRT)
 301                                 printf("/srcrt");
 302                         if (flags & DVMRP_NF_QUERIER)
 303                                 printf("/querier");
 304                         if (flags & DVMRP_NF_DISABLED)
 305                                 printf("/disabled");
 306                         if (flags & DVMRP_NF_DOWN)
 307                                 printf("/down");
 308                         printf(")]");
 309                         len -= 4;
 310                 }
 311                 if (ncount != -1) {
 312                         printf(" [|]");
 313                         return;
 314                 }
 315         }
 316 }
 317
 318 static void
 319 print_prune(register const u_char *bp, register const u_char *ep,
 320     register u_int len)
 321 {
 322         union a {
 323                 u_char b[4];
 324                 u_int32_t i;
 325         } prune_timer;
 326
 327         if (len < 12 || (bp + 12) > ep) {
 328                 printf(" [|]");
 329                 return;
 330         }
 331         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 332         bp += 8;
 333         GET_ADDR(prune_timer.b);
 334         printf(" timer %d", (int)ntohl(prune_timer.i));
 335 }
 336
 337 static void
 338 print_graft(register const u_char *bp, register const u_char *ep,
 339     register u_int len)
 340 {
 341
 342         if (len < 8 || (bp + 8) > ep) {
 343                 printf(" [|]");
 344                 return;
 345         }
 346         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 347 }
 348
 349 static void
 350 print_graft_ack(register const u_char *bp, register const u_char *ep,
 351     register u_int len)
 352 {
 353
 354         if (len < 8 || (bp + 8) > ep) {
 355                 printf(" [|]");
 356                 return;
 357         }
 358         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 359 }