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 1.18 2000-09-23 08:26:33 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 #include <netinet/in_systm.h>
  37 #include <netinet/ip.h>
  38 #include <netinet/ip_var.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 "extract.h"
  47 #include "addrtoname.h"
  48
  49 /*
  50  * DVMRP message types and flag values shamelessly stolen from
  51  * mrouted/dvmrp.h.
  52  */
  53 #define DVMRP_PROBE             1       /* for finding neighbors */
  54 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  55 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  56                                         /*
  57                                          * of this router's neighbors
  58                                          */
  59 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  60 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  61 #define DVMRP_NEIGHBORS2        6
  62 #define DVMRP_PRUNE             7       /* prune message */
  63 #define DVMRP_GRAFT             8       /* graft message */
  64 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  65
  66 /*
  67  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  68  */
  69 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  70 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  71 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  72 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  73 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  74
  75 static void print_probe(const u_char *, const u_char *, u_int);
  76 static void print_report(const u_char *, const u_char *, u_int);
  77 static void print_neighbors(const u_char *, const u_char *, u_int);
  78 static void print_neighbors2(const u_char *, const u_char *, u_int);
  79 static void print_prune(const u_char *, const u_char *, u_int);
  80 static void print_graft(const u_char *, const u_char *, u_int);
  81 static void print_graft_ack(const u_char *, const u_char *, u_int);
  82
  83 static u_int32_t target_level;
  84
  85 void
  86 dvmrp_print(register const u_char *bp, register u_int len)
  87 {
  88         register const u_char *ep;
  89         register u_char type;
  90
  91         ep = (const u_char *)snapend;
  92         if (bp >= ep)
  93                 return;
  94
  95         type = bp[1];
  96         bp += 8;
  97         /*
  98          * Skip IGMP header
  99          */
 100
 101         len -= 8;
 102
 103         switch (type) {
 104
 105         case DVMRP_PROBE:
 106                 printf(" Probe");
 107                 if (vflag)
 108                         print_probe(bp, ep, len);
 109                 break;
 110
 111         case DVMRP_REPORT:
 112                 printf(" Report");
 113                 if (vflag)
 114                         print_report(bp, ep, len);
 115                 break;
 116
 117         case DVMRP_ASK_NEIGHBORS:
 118                 printf(" Ask-neighbors(old)");
 119                 break;
 120
 121         case DVMRP_NEIGHBORS:
 122                 printf(" Neighbors(old)");
 123                 print_neighbors(bp, ep, len);
 124                 break;
 125
 126         case DVMRP_ASK_NEIGHBORS2:
 127                 printf(" Ask-neighbors2");
 128                 break;
 129
 130         case DVMRP_NEIGHBORS2:
 131                 printf(" Neighbors2");
 132                 /*
 133                  * extract version and capabilities from IGMP group
 134                  * address field
 135                  */
 136                 bp -= 4;
 137                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 138                     (bp[2] << 8) | bp[3];
 139                 bp += 4;
 140                 print_neighbors2(bp, ep, len);
 141                 break;
 142
 143         case DVMRP_PRUNE:
 144                 printf(" Prune");
 145                 print_prune(bp, ep, len);
 146                 break;
 147
 148         case DVMRP_GRAFT:
 149                 printf(" Graft");
 150                 print_graft(bp, ep, len);
 151                 break;
 152
 153         case DVMRP_GRAFT_ACK:
 154                 printf(" Graft-ACK");
 155                 print_graft_ack(bp, ep, len);
 156                 break;
 157
 158         default:
 159                 printf(" [type %d]", type);
 160                 break;
 161         }
 162 }
 163
 164 static void
 165 print_report(register const u_char *bp, register const u_char *ep,
 166     register u_int len)
 167 {
 168         register u_int32_t mask, origin;
 169         register int metric, i, width, done;
 170
 171         while (len > 0) {
 172                 if (len < 3) {
 173                         printf(" [|]");
 174                         return;
 175                 }
 176                 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 177                 width = 1;
 178                 if (bp[0])
 179                         width = 2;
 180                 if (bp[1])
 181                         width = 3;
 182                 if (bp[2])
 183                         width = 4;
 184
 185                 printf("\n\tMask %s", intoa(htonl(mask)));
 186                 bp += 3;
 187                 len -= 3;
 188                 do {
 189                         if (bp + width + 1 > ep) {
 190                                 printf(" [|]");
 191                                 return;
 192                         }
 193                         if (len < width + 1) {
 194                                 printf("\n\t  [Truncated Report]");
 195                                 return;
 196                         }
 197                         origin = 0;
 198                         for (i = 0; i < width; ++i)
 199                                 origin = origin << 8 | *bp++;
 200                         for ( ; i < 4; ++i)
 201                                 origin <<= 8;
 202
 203                         metric = *bp++;
 204                         done = metric & 0x80;
 205                         metric &= 0x7f;
 206                         printf("\n\t  %s metric %d", intoa(htonl(origin)),
 207                                 metric);
 208                         len -= width + 1;
 209                 } while (!done);
 210         }
 211 }
 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
 219         TCHECK2(bp[0], 4);
 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                 TCHECK2(bp[0], 4);
 232                 printf("\n\tneighbor %s", ipaddr_string(bp));
 233                 bp += 4; len -= 4;
 234         }
 235         return;
 236 trunc:
 237         (void)printf("[|dvmrp]");
 238 }
 239
 240 static void
 241 print_neighbors(register const u_char *bp, register const u_char *ep,
 242     register u_int len)
 243 {
 244         const u_char *laddr;
 245         register u_char metric;
 246         register u_char thresh;
 247         register int ncount;
 248
 249         while (len > 0 && bp < ep) {
 250                 TCHECK2(bp[0], 7);
 251                 laddr = bp;
 252                 bp += 4;
 253                 metric = *bp++;
 254                 thresh = *bp++;
 255                 ncount = *bp++;
 256                 len -= 7;
 257                 while (--ncount >= 0) {
 258                         TCHECK2(bp[0], 4);
 259                         printf(" [%s ->", ipaddr_string(laddr));
 260                         printf(" %s, (%d/%d)]",
 261                                    ipaddr_string(bp), metric, thresh);
 262                         bp += 4;
 263                         len -= 4;
 264                 }
 265         }
 266         return;
 267 trunc:
 268         (void)printf("[|dvmrp]");
 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         const u_char *laddr;
 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                 TCHECK2(bp[0], 8);
 285                 laddr = bp;
 286                 bp += 4;
 287                 metric = *bp++;
 288                 thresh = *bp++;
 289                 flags = *bp++;
 290                 ncount = *bp++;
 291                 len -= 8;
 292                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 293                         printf(" [%s -> ", ipaddr_string(laddr));
 294                         printf("%s (%d/%d", ipaddr_string(bp),
 295                                      metric, thresh);
 296                         if (flags & DVMRP_NF_TUNNEL)
 297                                 printf("/tunnel");
 298                         if (flags & DVMRP_NF_SRCRT)
 299                                 printf("/srcrt");
 300                         if (flags & DVMRP_NF_QUERIER)
 301                                 printf("/querier");
 302                         if (flags & DVMRP_NF_DISABLED)
 303                                 printf("/disabled");
 304                         if (flags & DVMRP_NF_DOWN)
 305                                 printf("/down");
 306                         printf(")]");
 307                         bp += 4;
 308                         len -= 4;
 309                 }
 310                 if (ncount != -1) {
 311                         printf(" [|]");
 312                         return;
 313                 }
 314         }
 315         return;
 316 trunc:
 317         (void)printf("[|dvmrp]");
 318 }
 319
 320 static void
 321 print_prune(register const u_char *bp, register const u_char *ep,
 322     register u_int len)
 323 {
 324         TCHECK2(bp[0], 12);
 325         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 326         bp += 8;
 327         (void)printf(" timer ");
 328         relts_print(EXTRACT_32BITS(bp));
 329         return;
 330 trunc:
 331         (void)printf("[|dvmrp]");
 332 }
 333
 334 static void
 335 print_graft(register const u_char *bp, register const u_char *ep,
 336     register u_int len)
 337 {
 338         TCHECK2(bp[0], 8);
 339         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 340         return;
 341 trunc:
 342         (void)printf("[|dvmrp]");
 343 }
 344
 345 static void
 346 print_graft_ack(register const u_char *bp, register const u_char *ep,
 347     register u_int len)
 348 {
 349         TCHECK2(bp[0], 8);
 350         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 351         return;
 352 trunc:
 353         (void)printf("[|dvmrp]");
 354 }