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 1.22 2002-08-01 08:53:05 risso Exp $ (LBL)";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <tcpdump-stdinc.h>
  32
  33 #include <stdio.h>
  34 #include <string.h>
  35 #include <stdlib.h>
  36
  37 #include "interface.h"
  38 #include "extract.h"
  39 #include "addrtoname.h"
  40
  41 /*
  42  * DVMRP message types and flag values shamelessly stolen from
  43  * mrouted/dvmrp.h.
  44  */
  45 #define DVMRP_PROBE             1       /* for finding neighbors */
  46 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  47 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  48                                         /* of this router's neighbors */
  49 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  50 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  51 #define DVMRP_NEIGHBORS2        6
  52 #define DVMRP_PRUNE             7       /* prune message */
  53 #define DVMRP_GRAFT             8       /* graft message */
  54 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  55
  56 /*
  57  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  58  */
  59 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  60 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  61 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  62 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  63 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  64
  65 static void print_probe(const u_char *, const u_char *, u_int);
  66 static void print_report(const u_char *, const u_char *, u_int);
  67 static void print_neighbors(const u_char *, const u_char *, u_int);
  68 static void print_neighbors2(const u_char *, const u_char *, u_int);
  69 static void print_prune(const u_char *, const u_char *, u_int);
  70 static void print_graft(const u_char *, const u_char *, u_int);
  71 static void print_graft_ack(const u_char *, const u_char *, u_int);
  72
  73 static u_int32_t target_level;
  74
  75 void
  76 dvmrp_print(register const u_char *bp, register u_int len)
  77 {
  78         register const u_char *ep;
  79         register u_char type;
  80
  81         ep = (const u_char *)snapend;
  82         if (bp >= ep)
  83                 return;
  84
  85         type = bp[1];
  86
  87         /* Skip IGMP header */
  88         bp += 8;
  89         len -= 8;
  90
  91         switch (type) {
  92
  93         case DVMRP_PROBE:
  94                 printf(" Probe");
  95                 if (vflag)
  96                         print_probe(bp, ep, len);
  97                 break;
  98
  99         case DVMRP_REPORT:
 100                 printf(" Report");
 101                 if (vflag > 1)
 102                         print_report(bp, ep, len);
 103                 break;
 104
 105         case DVMRP_ASK_NEIGHBORS:
 106                 printf(" Ask-neighbors(old)");
 107                 break;
 108
 109         case DVMRP_NEIGHBORS:
 110                 printf(" Neighbors(old)");
 111                 print_neighbors(bp, ep, len);
 112                 break;
 113
 114         case DVMRP_ASK_NEIGHBORS2:
 115                 printf(" Ask-neighbors2");
 116                 break;
 117
 118         case DVMRP_NEIGHBORS2:
 119                 printf(" Neighbors2");
 120                 /*
 121                  * extract version and capabilities from IGMP group
 122                  * address field
 123                  */
 124                 bp -= 4;
 125                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 126                     (bp[2] << 8) | bp[3];
 127                 bp += 4;
 128                 print_neighbors2(bp, ep, len);
 129                 break;
 130
 131         case DVMRP_PRUNE:
 132                 printf(" Prune");
 133                 print_prune(bp, ep, len);
 134                 break;
 135
 136         case DVMRP_GRAFT:
 137                 printf(" Graft");
 138                 print_graft(bp, ep, len);
 139                 break;
 140
 141         case DVMRP_GRAFT_ACK:
 142                 printf(" Graft-ACK");
 143                 print_graft_ack(bp, ep, len);
 144                 break;
 145
 146         default:
 147                 printf(" [type %d]", type);
 148                 break;
 149         }
 150 }
 151
 152 static void
 153 print_report(register const u_char *bp, register const u_char *ep,
 154     register u_int len)
 155 {
 156         register u_int32_t mask, origin;
 157         register int metric, i, width, done;
 158
 159         while (len > 0) {
 160                 if (len < 3) {
 161                         printf(" [|]");
 162                         return;
 163                 }
 164                 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 165                 width = 1;
 166                 if (bp[0])
 167                         width = 2;
 168                 if (bp[1])
 169                         width = 3;
 170                 if (bp[2])
 171                         width = 4;
 172
 173                 printf("\n\tMask %s", intoa(htonl(mask)));
 174                 bp += 3;
 175                 len -= 3;
 176                 do {
 177                         if (bp + width + 1 > ep) {
 178                                 printf(" [|]");
 179                                 return;
 180                         }
 181                         if (len < width + 1) {
 182                                 printf("\n\t  [Truncated Report]");
 183                                 return;
 184                         }
 185                         origin = 0;
 186                         for (i = 0; i < width; ++i)
 187                                 origin = origin << 8 | *bp++;
 188                         for ( ; i < 4; ++i)
 189                                 origin <<= 8;
 190
 191                         metric = *bp++;
 192                         done = metric & 0x80;
 193                         metric &= 0x7f;
 194                         printf("\n\t  %s metric %d", intoa(htonl(origin)),
 195                                 metric);
 196                         len -= width + 1;
 197                 } while (!done);
 198         }
 199 }
 200
 201 static void
 202 print_probe(register const u_char *bp, register const u_char *ep,
 203     register u_int len)
 204 {
 205         register u_int32_t genid;
 206
 207         TCHECK2(bp[0], 4);
 208         if ((len < 4) || ((bp + 4) > ep)) {
 209                 /* { (ctags) */
 210                 printf(" [|}");
 211                 return;
 212         }
 213         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 214         bp += 4;
 215         len -= 4;
 216         if (vflag > 1)
 217                 printf("\n\t");
 218         else
 219                 printf(" ");
 220         printf("genid %u", genid);
 221         if (vflag < 2)
 222                 return;
 223
 224         while ((len > 0) && (bp < ep)) {
 225                 TCHECK2(bp[0], 4);
 226                 printf("\n\tneighbor %s", ipaddr_string(bp));
 227                 bp += 4; len -= 4;
 228         }
 229         return;
 230 trunc:
 231         (void)printf("[|dvmrp]");
 232 }
 233
 234 static void
 235 print_neighbors(register const u_char *bp, register const u_char *ep,
 236     register u_int len)
 237 {
 238         const u_char *laddr;
 239         register u_char metric;
 240         register u_char thresh;
 241         register int ncount;
 242
 243         while (len > 0 && bp < ep) {
 244                 TCHECK2(bp[0], 7);
 245                 laddr = bp;
 246                 bp += 4;
 247                 metric = *bp++;
 248                 thresh = *bp++;
 249                 ncount = *bp++;
 250                 len -= 7;
 251                 while (--ncount >= 0) {
 252                         TCHECK2(bp[0], 4);
 253                         printf(" [%s ->", ipaddr_string(laddr));
 254                         printf(" %s, (%d/%d)]",
 255                                    ipaddr_string(bp), metric, thresh);
 256                         bp += 4;
 257                         len -= 4;
 258                 }
 259         }
 260         return;
 261 trunc:
 262         (void)printf("[|dvmrp]");
 263 }
 264
 265 static void
 266 print_neighbors2(register const u_char *bp, register const u_char *ep,
 267     register u_int len)
 268 {
 269         const u_char *laddr;
 270         register u_char metric, thresh, flags;
 271         register int ncount;
 272
 273         printf(" (v %d.%d):",
 274                (int)target_level & 0xff,
 275                (int)(target_level >> 8) & 0xff);
 276
 277         while (len > 0 && bp < ep) {
 278                 TCHECK2(bp[0], 8);
 279                 laddr = bp;
 280                 bp += 4;
 281                 metric = *bp++;
 282                 thresh = *bp++;
 283                 flags = *bp++;
 284                 ncount = *bp++;
 285                 len -= 8;
 286                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 287                         printf(" [%s -> ", ipaddr_string(laddr));
 288                         printf("%s (%d/%d", ipaddr_string(bp),
 289                                      metric, thresh);
 290                         if (flags & DVMRP_NF_TUNNEL)
 291                                 printf("/tunnel");
 292                         if (flags & DVMRP_NF_SRCRT)
 293                                 printf("/srcrt");
 294                         if (flags & DVMRP_NF_QUERIER)
 295                                 printf("/querier");
 296                         if (flags & DVMRP_NF_DISABLED)
 297                                 printf("/disabled");
 298                         if (flags & DVMRP_NF_DOWN)
 299                                 printf("/down");
 300                         printf(")]");
 301                         bp += 4;
 302                         len -= 4;
 303                 }
 304                 if (ncount != -1) {
 305                         printf(" [|]");
 306                         return;
 307                 }
 308         }
 309         return;
 310 trunc:
 311         (void)printf("[|dvmrp]");
 312 }
 313
 314 static void
 315 print_prune(register const u_char *bp, register const u_char *ep,
 316     register u_int len)
 317 {
 318         TCHECK2(bp[0], 12);
 319         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 320         bp += 8;
 321         (void)printf(" timer ");
 322         relts_print(EXTRACT_32BITS(bp));
 323         return;
 324 trunc:
 325         (void)printf("[|dvmrp]");
 326 }
 327
 328 static void
 329 print_graft(register const u_char *bp, register const u_char *ep,
 330     register u_int len)
 331 {
 332         TCHECK2(bp[0], 8);
 333         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 334         return;
 335 trunc:
 336         (void)printf("[|dvmrp]");
 337 }
 338
 339 static void
 340 print_graft_ack(register const u_char *bp, register const u_char *ep,
 341     register u_int len)
 342 {
 343         TCHECK2(bp[0], 8);
 344         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 345         return;
 346 trunc:
 347         (void)printf("[|dvmrp]");
 348 }