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 1.21 2001-05-10 05:30:20 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
  37 #include <stdio.h>
  38 #include <string.h>
  39 #include <stdlib.h>
  40 #include <unistd.h>
  41
  42 #include "interface.h"
  43 #include "extract.h"
  44 #include "addrtoname.h"
  45
  46 /*
  47  * DVMRP message types and flag values shamelessly stolen from
  48  * mrouted/dvmrp.h.
  49  */
  50 #define DVMRP_PROBE             1       /* for finding neighbors */
  51 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  52 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  53                                         /* of this router's neighbors */
  54 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  55 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  56 #define DVMRP_NEIGHBORS2        6
  57 #define DVMRP_PRUNE             7       /* prune message */
  58 #define DVMRP_GRAFT             8       /* graft message */
  59 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  60
  61 /*
  62  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  63  */
  64 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  65 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  66 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  67 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  68 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  69
  70 static void print_probe(const u_char *, const u_char *, u_int);
  71 static void print_report(const u_char *, const u_char *, u_int);
  72 static void print_neighbors(const u_char *, const u_char *, u_int);
  73 static void print_neighbors2(const u_char *, const u_char *, u_int);
  74 static void print_prune(const u_char *, const u_char *, u_int);
  75 static void print_graft(const u_char *, const u_char *, u_int);
  76 static void print_graft_ack(const u_char *, const u_char *, u_int);
  77
  78 static u_int32_t target_level;
  79
  80 void
  81 dvmrp_print(register const u_char *bp, register u_int len)
  82 {
  83         register const u_char *ep;
  84         register u_char type;
  85
  86         ep = (const u_char *)snapend;
  87         if (bp >= ep)
  88                 return;
  89
  90         type = bp[1];
  91
  92         /* Skip IGMP header */
  93         bp += 8;
  94         len -= 8;
  95
  96         switch (type) {
  97
  98         case DVMRP_PROBE:
  99                 printf(" Probe");
 100                 if (vflag)
 101                         print_probe(bp, ep, len);
 102                 break;
 103
 104         case DVMRP_REPORT:
 105                 printf(" Report");
 106                 if (vflag > 1)
 107                         print_report(bp, ep, len);
 108                 break;
 109
 110         case DVMRP_ASK_NEIGHBORS:
 111                 printf(" Ask-neighbors(old)");
 112                 break;
 113
 114         case DVMRP_NEIGHBORS:
 115                 printf(" Neighbors(old)");
 116                 print_neighbors(bp, ep, len);
 117                 break;
 118
 119         case DVMRP_ASK_NEIGHBORS2:
 120                 printf(" Ask-neighbors2");
 121                 break;
 122
 123         case DVMRP_NEIGHBORS2:
 124                 printf(" Neighbors2");
 125                 /*
 126                  * extract version and capabilities from IGMP group
 127                  * address field
 128                  */
 129                 bp -= 4;
 130                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 131                     (bp[2] << 8) | bp[3];
 132                 bp += 4;
 133                 print_neighbors2(bp, ep, len);
 134                 break;
 135
 136         case DVMRP_PRUNE:
 137                 printf(" Prune");
 138                 print_prune(bp, ep, len);
 139                 break;
 140
 141         case DVMRP_GRAFT:
 142                 printf(" Graft");
 143                 print_graft(bp, ep, len);
 144                 break;
 145
 146         case DVMRP_GRAFT_ACK:
 147                 printf(" Graft-ACK");
 148                 print_graft_ack(bp, ep, len);
 149                 break;
 150
 151         default:
 152                 printf(" [type %d]", type);
 153                 break;
 154         }
 155 }
 156
 157 static void
 158 print_report(register const u_char *bp, register const u_char *ep,
 159     register u_int len)
 160 {
 161         register u_int32_t mask, origin;
 162         register int metric, i, width, done;
 163
 164         while (len > 0) {
 165                 if (len < 3) {
 166                         printf(" [|]");
 167                         return;
 168                 }
 169                 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 170                 width = 1;
 171                 if (bp[0])
 172                         width = 2;
 173                 if (bp[1])
 174                         width = 3;
 175                 if (bp[2])
 176                         width = 4;
 177
 178                 printf("\n\tMask %s", intoa(htonl(mask)));
 179                 bp += 3;
 180                 len -= 3;
 181                 do {
 182                         if (bp + width + 1 > ep) {
 183                                 printf(" [|]");
 184                                 return;
 185                         }
 186                         if (len < width + 1) {
 187                                 printf("\n\t  [Truncated Report]");
 188                                 return;
 189                         }
 190                         origin = 0;
 191                         for (i = 0; i < width; ++i)
 192                                 origin = origin << 8 | *bp++;
 193                         for ( ; i < 4; ++i)
 194                                 origin <<= 8;
 195
 196                         metric = *bp++;
 197                         done = metric & 0x80;
 198                         metric &= 0x7f;
 199                         printf("\n\t  %s metric %d", intoa(htonl(origin)),
 200                                 metric);
 201                         len -= width + 1;
 202                 } while (!done);
 203         }
 204 }
 205
 206 static void
 207 print_probe(register const u_char *bp, register const u_char *ep,
 208     register u_int len)
 209 {
 210         register u_int32_t genid;
 211
 212         TCHECK2(bp[0], 4);
 213         if ((len < 4) || ((bp + 4) > ep)) {
 214                 /* { (ctags) */
 215                 printf(" [|}");
 216                 return;
 217         }
 218         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 219         bp += 4;
 220         len -= 4;
 221         if (vflag > 1)
 222                 printf("\n\t");
 223         else
 224                 printf(" ");
 225         printf("genid %u", genid);
 226         if (vflag < 2)
 227                 return;
 228
 229         while ((len > 0) && (bp < ep)) {
 230                 TCHECK2(bp[0], 4);
 231                 printf("\n\tneighbor %s", ipaddr_string(bp));
 232                 bp += 4; len -= 4;
 233         }
 234         return;
 235 trunc:
 236         (void)printf("[|dvmrp]");
 237 }
 238
 239 static void
 240 print_neighbors(register const u_char *bp, register const u_char *ep,
 241     register u_int len)
 242 {
 243         const u_char *laddr;
 244         register u_char metric;
 245         register u_char thresh;
 246         register int ncount;
 247
 248         while (len > 0 && bp < ep) {
 249                 TCHECK2(bp[0], 7);
 250                 laddr = bp;
 251                 bp += 4;
 252                 metric = *bp++;
 253                 thresh = *bp++;
 254                 ncount = *bp++;
 255                 len -= 7;
 256                 while (--ncount >= 0) {
 257                         TCHECK2(bp[0], 4);
 258                         printf(" [%s ->", ipaddr_string(laddr));
 259                         printf(" %s, (%d/%d)]",
 260                                    ipaddr_string(bp), metric, thresh);
 261                         bp += 4;
 262                         len -= 4;
 263                 }
 264         }
 265         return;
 266 trunc:
 267         (void)printf("[|dvmrp]");
 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         const u_char *laddr;
 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                 TCHECK2(bp[0], 8);
 284                 laddr = bp;
 285                 bp += 4;
 286                 metric = *bp++;
 287                 thresh = *bp++;
 288                 flags = *bp++;
 289                 ncount = *bp++;
 290                 len -= 8;
 291                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 292                         printf(" [%s -> ", ipaddr_string(laddr));
 293                         printf("%s (%d/%d", ipaddr_string(bp),
 294                                      metric, thresh);
 295                         if (flags & DVMRP_NF_TUNNEL)
 296                                 printf("/tunnel");
 297                         if (flags & DVMRP_NF_SRCRT)
 298                                 printf("/srcrt");
 299                         if (flags & DVMRP_NF_QUERIER)
 300                                 printf("/querier");
 301                         if (flags & DVMRP_NF_DISABLED)
 302                                 printf("/disabled");
 303                         if (flags & DVMRP_NF_DOWN)
 304                                 printf("/down");
 305                         printf(")]");
 306                         bp += 4;
 307                         len -= 4;
 308                 }
 309                 if (ncount != -1) {
 310                         printf(" [|]");
 311                         return;
 312                 }
 313         }
 314         return;
 315 trunc:
 316         (void)printf("[|dvmrp]");
 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         TCHECK2(bp[0], 12);
 324         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 325         bp += 8;
 326         (void)printf(" timer ");
 327         relts_print(EXTRACT_32BITS(bp));
 328         return;
 329 trunc:
 330         (void)printf("[|dvmrp]");
 331 }
 332
 333 static void
 334 print_graft(register const u_char *bp, register const u_char *ep,
 335     register u_int len)
 336 {
 337         TCHECK2(bp[0], 8);
 338         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 339         return;
 340 trunc:
 341         (void)printf("[|dvmrp]");
 342 }
 343
 344 static void
 345 print_graft_ack(register const u_char *bp, register const u_char *ep,
 346     register u_int len)
 347 {
 348         TCHECK2(bp[0], 8);
 349         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 350         return;
 351 trunc:
 352         (void)printf("[|dvmrp]");
 353 }