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 1.17 1999-11-22 04:30:34 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 "extract.h"
  50 #include "addrtoname.h"
  51
  52 /*
  53  * DVMRP message types and flag values shamelessly stolen from
  54  * mrouted/dvmrp.h.
  55  */
  56 #define DVMRP_PROBE             1       /* for finding neighbors */
  57 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  58 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  59                                         /*
  60                                          * of this router's neighbors
  61                                          */
  62 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  63 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  64 #define DVMRP_NEIGHBORS2        6
  65 #define DVMRP_PRUNE             7       /* prune message */
  66 #define DVMRP_GRAFT             8       /* graft message */
  67 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  68
  69 /*
  70  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  71  */
  72 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  73 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  74 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  75 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  76 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  77
  78 static void print_probe(const u_char *, const u_char *, u_int);
  79 static void print_report(const u_char *, const u_char *, u_int);
  80 static void print_neighbors(const u_char *, const u_char *, u_int);
  81 static void print_neighbors2(const u_char *, const u_char *, u_int);
  82 static void print_prune(const u_char *, const u_char *, u_int);
  83 static void print_graft(const u_char *, const u_char *, u_int);
  84 static void print_graft_ack(const u_char *, const u_char *, u_int);
  85
  86 static u_int32_t target_level;
  87
  88 void
  89 dvmrp_print(register const u_char *bp, register u_int len)
  90 {
  91         register const u_char *ep;
  92         register u_char type;
  93
  94         ep = (const u_char *)snapend;
  95         if (bp >= ep)
  96                 return;
  97
  98         type = bp[1];
  99         bp += 8;
 100         /*
 101          * Skip IGMP header
 102          */
 103
 104         len -= 8;
 105
 106         switch (type) {
 107
 108         case DVMRP_PROBE:
 109                 printf(" Probe");
 110                 if (vflag)
 111                         print_probe(bp, ep, len);
 112                 break;
 113
 114         case DVMRP_REPORT:
 115                 printf(" Report");
 116                 if (vflag)
 117                         print_report(bp, ep, len);
 118                 break;
 119
 120         case DVMRP_ASK_NEIGHBORS:
 121                 printf(" Ask-neighbors(old)");
 122                 break;
 123
 124         case DVMRP_NEIGHBORS:
 125                 printf(" Neighbors(old)");
 126                 print_neighbors(bp, ep, len);
 127                 break;
 128
 129         case DVMRP_ASK_NEIGHBORS2:
 130                 printf(" Ask-neighbors2");
 131                 break;
 132
 133         case DVMRP_NEIGHBORS2:
 134                 printf(" Neighbors2");
 135                 /*
 136                  * extract version and capabilities from IGMP group
 137                  * address field
 138                  */
 139                 bp -= 4;
 140                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 141                     (bp[2] << 8) | bp[3];
 142                 bp += 4;
 143                 print_neighbors2(bp, ep, len);
 144                 break;
 145
 146         case DVMRP_PRUNE:
 147                 printf(" Prune");
 148                 print_prune(bp, ep, len);
 149                 break;
 150
 151         case DVMRP_GRAFT:
 152                 printf(" Graft");
 153                 print_graft(bp, ep, len);
 154                 break;
 155
 156         case DVMRP_GRAFT_ACK:
 157                 printf(" Graft-ACK");
 158                 print_graft_ack(bp, ep, len);
 159                 break;
 160
 161         default:
 162                 printf(" [type %d]", type);
 163                 break;
 164         }
 165 }
 166
 167 static void
 168 print_report(register const u_char *bp, register const u_char *ep,
 169     register u_int len)
 170 {
 171         register u_int32_t mask, origin;
 172         register int metric, i, width, done;
 173
 174         while (len > 0) {
 175                 if (len < 3) {
 176                         printf(" [|]");
 177                         return;
 178                 }
 179                 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 180                 width = 1;
 181                 if (bp[0])
 182                         width = 2;
 183                 if (bp[1])
 184                         width = 3;
 185                 if (bp[2])
 186                         width = 4;
 187
 188                 printf("\n\tMask %s", intoa(htonl(mask)));
 189                 bp += 3;
 190                 len -= 3;
 191                 do {
 192                         if (bp + width + 1 > ep) {
 193                                 printf(" [|]");
 194                                 return;
 195                         }
 196                         if (len < width + 1) {
 197                                 printf("\n\t  [Truncated Report]");
 198                                 return;
 199                         }
 200                         origin = 0;
 201                         for (i = 0; i < width; ++i)
 202                                 origin = origin << 8 | *bp++;
 203                         for ( ; i < 4; ++i)
 204                                 origin <<= 8;
 205
 206                         metric = *bp++;
 207                         done = metric & 0x80;
 208                         metric &= 0x7f;
 209                         printf("\n\t  %s metric %d", intoa(htonl(origin)),
 210                                 metric);
 211                         len -= width + 1;
 212                 } while (!done);
 213         }
 214 }
 215
 216 static void
 217 print_probe(register const u_char *bp, register const u_char *ep,
 218     register u_int len)
 219 {
 220         register u_int32_t genid;
 221
 222         TCHECK2(bp[0], 4);
 223         if ((len < 4) || ((bp + 4) > ep)) {
 224                 /* { (ctags) */
 225                 printf(" [|}");
 226                 return;
 227         }
 228         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 229         bp += 4;
 230         len -= 4;
 231         printf("\n\tgenid %u", genid);
 232
 233         while ((len > 0) && (bp < ep)) {
 234                 TCHECK2(bp[0], 4);
 235                 printf("\n\tneighbor %s", ipaddr_string(bp));
 236                 bp += 4; len -= 4;
 237         }
 238         return;
 239 trunc:
 240         (void)printf("[|dvmrp]");
 241 }
 242
 243 static void
 244 print_neighbors(register const u_char *bp, register const u_char *ep,
 245     register u_int len)
 246 {
 247         const u_char *laddr;
 248         register u_char metric;
 249         register u_char thresh;
 250         register int ncount;
 251
 252         while (len > 0 && bp < ep) {
 253                 TCHECK2(bp[0], 7);
 254                 laddr = bp;
 255                 bp += 4;
 256                 metric = *bp++;
 257                 thresh = *bp++;
 258                 ncount = *bp++;
 259                 len -= 7;
 260                 while (--ncount >= 0) {
 261                         TCHECK2(bp[0], 4);
 262                         printf(" [%s ->", ipaddr_string(laddr));
 263                         printf(" %s, (%d/%d)]",
 264                                    ipaddr_string(bp), metric, thresh);
 265                         bp += 4;
 266                         len -= 4;
 267                 }
 268         }
 269         return;
 270 trunc:
 271         (void)printf("[|dvmrp]");
 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         const u_char *laddr;
 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                 TCHECK2(bp[0], 8);
 288                 laddr = bp;
 289                 bp += 4;
 290                 metric = *bp++;
 291                 thresh = *bp++;
 292                 flags = *bp++;
 293                 ncount = *bp++;
 294                 len -= 8;
 295                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 296                         printf(" [%s -> ", ipaddr_string(laddr));
 297                         printf("%s (%d/%d", ipaddr_string(bp),
 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                         bp += 4;
 311                         len -= 4;
 312                 }
 313                 if (ncount != -1) {
 314                         printf(" [|]");
 315                         return;
 316                 }
 317         }
 318         return;
 319 trunc:
 320         (void)printf("[|dvmrp]");
 321 }
 322
 323 static void
 324 print_prune(register const u_char *bp, register const u_char *ep,
 325     register u_int len)
 326 {
 327         TCHECK2(bp[0], 12);
 328         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 329         bp += 8;
 330         (void)printf(" timer ");
 331         relts_print(EXTRACT_32BITS(bp));
 332         return;
 333 trunc:
 334         (void)printf("[|dvmrp]");
 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         TCHECK2(bp[0], 8);
 342         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 343         return;
 344 trunc:
 345         (void)printf("[|dvmrp]");
 346 }
 347
 348 static void
 349 print_graft_ack(register const u_char *bp, register const u_char *ep,
 350     register u_int len)
 351 {
 352         TCHECK2(bp[0], 8);
 353         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 354         return;
 355 trunc:
 356         (void)printf("[|dvmrp]");
 357 }