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 1.13 1999-10-07 23:47:11 mcr 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 #include <netinet/tcpip.h>
  39
  40 #include <stdio.h>
  41 #include <string.h>
  42 #include <stdlib.h>
  43 #include <unistd.h>
  44
  45 #include "interface.h"
  46 #include "addrtoname.h"
  47
  48 /*
  49  * DVMRP message types and flag values shamelessly stolen from
  50  * mrouted/dvmrp.h.
  51  */
  52 #define DVMRP_PROBE             1       /* for finding neighbors */
  53 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  54 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  55                                         /*
  56                                          * of this router's neighbors
  57                                          */
  58 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  59 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  60 #define DVMRP_NEIGHBORS2        6
  61 #define DVMRP_PRUNE             7       /* prune message */
  62 #define DVMRP_GRAFT             8       /* graft message */
  63 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  64
  65 /*
  66  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  67  */
  68 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  69 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  70 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  71 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  72 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  73
  74 static void print_probe(const u_char *, const u_char *, u_int);
  75 static void print_report(const u_char *, const u_char *, u_int);
  76 static void print_neighbors(const u_char *, const u_char *, u_int);
  77 static void print_neighbors2(const u_char *, const u_char *, u_int);
  78 static void print_prune(const u_char *, const u_char *, u_int);
  79 static void print_graft(const u_char *, const u_char *, u_int);
  80 static void print_graft_ack(const u_char *, const u_char *, u_int);
  81
  82 static u_int32_t target_level;
  83
  84 void
  85 dvmrp_print(register const u_char *bp, register u_int len)
  86 {
  87         register const u_char *ep;
  88         register u_char type;
  89
  90         ep = (const u_char *)snapend;
  91         if (bp >= ep)
  92                 return;
  93
  94         type = bp[1];
  95         bp += 8;
  96         /*
  97          * Skip IGMP header
  98          */
  99
 100         len -= 8;
 101
 102         switch (type) {
 103
 104         case DVMRP_PROBE:
 105                 printf(" Probe");
 106                 if (vflag)
 107                         print_probe(bp, ep, len);
 108                 break;
 109
 110         case DVMRP_REPORT:
 111                 printf(" Report");
 112                 if (vflag)
 113                         print_report(bp, ep, len);
 114                 break;
 115
 116         case DVMRP_ASK_NEIGHBORS:
 117                 printf(" Ask-neighbors(old)");
 118                 break;
 119
 120         case DVMRP_NEIGHBORS:
 121                 printf(" Neighbors(old)");
 122                 print_neighbors(bp, ep, len);
 123                 break;
 124
 125         case DVMRP_ASK_NEIGHBORS2:
 126                 printf(" Ask-neighbors2");
 127                 break;
 128
 129         case DVMRP_NEIGHBORS2:
 130                 printf(" Neighbors2");
 131                 /*
 132                  * extract version and capabilities from IGMP group
 133                  * address field
 134                  */
 135                 bp -= 4;
 136                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 137                     (bp[2] << 8) | bp[3];
 138                 bp += 4;
 139                 print_neighbors2(bp, ep, len);
 140                 break;
 141
 142         case DVMRP_PRUNE:
 143                 printf(" Prune");
 144                 print_prune(bp, ep, len);
 145                 break;
 146
 147         case DVMRP_GRAFT:
 148                 printf(" Graft");
 149                 print_graft(bp, ep, len);
 150                 break;
 151
 152         case DVMRP_GRAFT_ACK:
 153                 printf(" Graft-ACK");
 154                 print_graft_ack(bp, ep, len);
 155                 break;
 156
 157         default:
 158                 printf(" [type %d]", type);
 159                 break;
 160         }
 161 }
 162
 163 static void
 164 print_report(register const u_char *bp, register const u_char *ep,
 165     register u_int len)
 166 {
 167         register u_int32_t mask, origin;
 168         register int metric, i, width, done;
 169
 170         while (len > 0) {
 171                 if (len < 3) {
 172                         printf(" [|]");
 173                         return;
 174                 }
 175                 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 176                 width = 1;
 177                 if (bp[0])
 178                         width = 2;
 179                 if (bp[1])
 180                         width = 3;
 181                 if (bp[2])
 182                         width = 4;
 183
 184                 printf("\n\tMask %s", intoa(htonl(mask)));
 185                 bp += 3;
 186                 len -= 3;
 187                 do {
 188                         if (bp + width + 1 > ep) {
 189                                 printf(" [|]");
 190                                 return;
 191                         }
 192                         if (len < width + 1) {
 193                                 printf("\n\t  [Truncated Report]");
 194                                 return;
 195                         }
 196                         origin = 0;
 197                         for (i = 0; i < width; ++i)
 198                                 origin = origin << 8 | *bp++;
 199                         for ( ; i < 4; ++i)
 200                                 origin <<= 8;
 201
 202                         metric = *bp++;
 203                         done = metric & 0x80;
 204                         metric &= 0x7f;
 205                         printf("\n\t  %s metric %d", intoa(htonl(origin)),
 206                                 metric);
 207                         len -= width + 1;
 208                 } while (!done);
 209         }
 210 }
 211
 212 #define GET_ADDR(to) (memcpy((char *)to, (char *)bp, 4), bp += 4)
 213
 214 static void
 215 print_probe(register const u_char *bp, register const u_char *ep,
 216     register u_int len)
 217 {
 218         register u_int32_t genid;
 219         u_char neighbor[4];
 220
 221         if ((len < 4) || ((bp + 4) > ep)) {
 222                 /* { (ctags) */
 223                 printf(" [|}");
 224                 return;
 225         }
 226         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 227         bp += 4;
 228         len -= 4;
 229         printf("\n\tgenid %u", genid);
 230
 231         while ((len > 0) && (bp < ep)) {
 232                 if ((len < 4) || ((bp + 4) > ep)) {
 233                         printf(" [|]");
 234                         return;
 235                 }
 236                 GET_ADDR(neighbor);
 237                 len -= 4;
 238                 printf("\n\tneighbor %s", ipaddr_string(neighbor));
 239         }
 240 }
 241
 242 static void
 243 print_neighbors(register const u_char *bp, register const u_char *ep,
 244     register u_int len)
 245 {
 246         u_char laddr[4], neighbor[4];
 247         register u_char metric;
 248         register u_char thresh;
 249         register int ncount;
 250
 251         while (len > 0 && bp < ep) {
 252                 if (len < 7 || (bp + 7) >= ep) {
 253                         printf(" [|]");
 254                         return;
 255                 }
 256                 GET_ADDR(laddr);
 257                 metric = *bp++;
 258                 thresh = *bp++;
 259                 ncount = *bp++;
 260                 len -= 7;
 261                 while (--ncount >= 0 && (len >= 4) && (bp + 4) < ep) {
 262                         GET_ADDR(neighbor);
 263                         printf(" [%s ->", ipaddr_string(laddr));
 264                         printf(" %s, (%d/%d)]",
 265                                    ipaddr_string(neighbor), metric, thresh);
 266                         len -= 4;
 267                 }
 268         }
 269 }
 270
 271 static void
 272 print_neighbors2(register const u_char *bp, register const u_char *ep,
 273     register u_int len)
 274 {
 275         u_char laddr[4], neighbor[4];
 276         register u_char metric, thresh, flags;
 277         register int ncount;
 278
 279         printf(" (v %d.%d):",
 280                (int)target_level & 0xff,
 281                (int)(target_level >> 8) & 0xff);
 282
 283         while (len > 0 && bp < ep) {
 284                 if (len < 8 || (bp + 8) >= ep) {
 285                         printf(" [|]");
 286                         return;
 287                 }
 288                 GET_ADDR(laddr);
 289                 metric = *bp++;
 290                 thresh = *bp++;
 291                 flags = *bp++;
 292                 ncount = *bp++;
 293                 len -= 8;
 294                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 295                         GET_ADDR(neighbor);
 296                         printf(" [%s -> ", ipaddr_string(laddr));
 297                         printf("%s (%d/%d", ipaddr_string(neighbor),
 298                                      metric, thresh);
 299                         if (flags & DVMRP_NF_TUNNEL)
 300                                 printf("/tunnel");
 301                         if (flags & DVMRP_NF_SRCRT)
 302                                 printf("/srcrt");
 303                         if (flags & DVMRP_NF_QUERIER)
 304                                 printf("/querier");
 305                         if (flags & DVMRP_NF_DISABLED)
 306                                 printf("/disabled");
 307                         if (flags & DVMRP_NF_DOWN)
 308                                 printf("/down");
 309                         printf(")]");
 310                         len -= 4;
 311                 }
 312                 if (ncount != -1) {
 313                         printf(" [|]");
 314                         return;
 315                 }
 316         }
 317 }
 318
 319 static void
 320 print_prune(register const u_char *bp, register const u_char *ep,
 321     register u_int len)
 322 {
 323         union a {
 324                 u_char b[4];
 325                 u_int32_t i;
 326         } prune_timer;
 327
 328         if (len < 12 || (bp + 12) > ep) {
 329                 printf(" [|]");
 330                 return;
 331         }
 332         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 333         bp += 8;
 334         GET_ADDR(prune_timer.b);
 335         printf(" timer %d", (int)ntohl(prune_timer.i));
 336 }
 337
 338 static void
 339 print_graft(register const u_char *bp, register const u_char *ep,
 340     register u_int len)
 341 {
 342
 343         if (len < 8 || (bp + 8) > ep) {
 344                 printf(" [|]");
 345                 return;
 346         }
 347         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 348 }
 349
 350 static void
 351 print_graft_ack(register const u_char *bp, register const u_char *ep,
 352     register u_int len)
 353 {
 354
 355         if (len < 8 || (bp + 8) > ep) {
 356                 printf(" [|]");
 357                 return;
 358         }
 359         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 360 }