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[] _U_ =
  24     "@(#) $Header: /tcpdump/master/tcpdump/print-dvmrp.c,v 1.27 2003-11-19 09:42:04 guy 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 int print_probe(const u_char *, const u_char *, u_int);
  66 static int print_report(const u_char *, const u_char *, u_int);
  67 static int print_neighbors(const u_char *, const u_char *, u_int);
  68 static int print_neighbors2(const u_char *, const u_char *, u_int);
  69 static int print_prune(const u_char *);
  70 static int print_graft(const u_char *);
  71 static int print_graft_ack(const u_char *);
  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         TCHECK(bp[1]);
  86         type = bp[1];
  87
  88         /* Skip IGMP header */
  89         bp += 8;
  90         len -= 8;
  91
  92         switch (type) {
  93
  94         case DVMRP_PROBE:
  95                 printf(" Probe");
  96                 if (vflag) {
  97                         if (print_probe(bp, ep, len) < 0)
  98                                 goto trunc;
  99                 }
 100                 break;
 101
 102         case DVMRP_REPORT:
 103                 printf(" Report");
 104                 if (vflag > 1) {
 105                         if (print_report(bp, ep, len) < 0)
 106                                 goto trunc;
 107                 }
 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                 if (print_neighbors(bp, ep, len) < 0)
 117                         goto trunc;
 118                 break;
 119
 120         case DVMRP_ASK_NEIGHBORS2:
 121                 printf(" Ask-neighbors2");
 122                 break;
 123
 124         case DVMRP_NEIGHBORS2:
 125                 printf(" Neighbors2");
 126                 /*
 127                  * extract version and capabilities from IGMP group
 128                  * address field
 129                  */
 130                 bp -= 4;
 131                 TCHECK2(bp[0], 4);
 132                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 133                     (bp[2] << 8) | bp[3];
 134                 bp += 4;
 135                 if (print_neighbors2(bp, ep, len) < 0)
 136                         goto trunc;
 137                 break;
 138
 139         case DVMRP_PRUNE:
 140                 printf(" Prune");
 141                 if (print_prune(bp) < 0)
 142                         goto trunc;
 143                 break;
 144
 145         case DVMRP_GRAFT:
 146                 printf(" Graft");
 147                 if (print_graft(bp) < 0)
 148                         goto trunc;
 149                 break;
 150
 151         case DVMRP_GRAFT_ACK:
 152                 printf(" Graft-ACK");
 153                 if (print_graft_ack(bp) < 0)
 154                         goto trunc;
 155                 break;
 156
 157         default:
 158                 printf(" [type %d]", type);
 159                 break;
 160         }
 161         return;
 162
 163 trunc:
 164         printf("[|dvmrp]");
 165         return;
 166 }
 167
 168 static int
 169 print_report(register const u_char *bp, register const u_char *ep,
 170     register u_int len)
 171 {
 172         register u_int32_t mask, origin;
 173         register int metric, done;
 174         register u_int i, width;
 175
 176         while (len > 0) {
 177                 if (len < 3) {
 178                         printf(" [|]");
 179                         return (0);
 180                 }
 181                 TCHECK2(bp[0], 3);
 182                 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 183                 width = 1;
 184                 if (bp[0])
 185                         width = 2;
 186                 if (bp[1])
 187                         width = 3;
 188                 if (bp[2])
 189                         width = 4;
 190
 191                 printf("\n\tMask %s", intoa(htonl(mask)));
 192                 bp += 3;
 193                 len -= 3;
 194                 do {
 195                         if (bp + width + 1 > ep) {
 196                                 printf(" [|]");
 197                                 return (0);
 198                         }
 199                         if (len < width + 1) {
 200                                 printf("\n\t  [Truncated Report]");
 201                                 return (0);
 202                         }
 203                         origin = 0;
 204                         for (i = 0; i < width; ++i) {
 205                                 TCHECK(*bp);
 206                                 origin = origin << 8 | *bp++;
 207                         }
 208                         for ( ; i < 4; ++i)
 209                                 origin <<= 8;
 210
 211                         TCHECK(*bp);
 212                         metric = *bp++;
 213                         done = metric & 0x80;
 214                         metric &= 0x7f;
 215                         printf("\n\t  %s metric %d", intoa(htonl(origin)),
 216                                 metric);
 217                         len -= width + 1;
 218                 } while (!done);
 219         }
 220         return (0);
 221 trunc:
 222         return (-1);
 223 }
 224
 225 static int
 226 print_probe(register const u_char *bp, register const u_char *ep,
 227     register u_int len)
 228 {
 229         register u_int32_t genid;
 230
 231         TCHECK2(bp[0], 4);
 232         if ((len < 4) || ((bp + 4) > ep)) {
 233                 /* { (ctags) */
 234                 printf(" [|}");
 235                 return (0);
 236         }
 237         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 238         bp += 4;
 239         len -= 4;
 240         if (vflag > 1)
 241                 printf("\n\t");
 242         else
 243                 printf(" ");
 244         printf("genid %u", genid);
 245         if (vflag < 2)
 246                 return (0);
 247
 248         while ((len > 0) && (bp < ep)) {
 249                 TCHECK2(bp[0], 4);
 250                 printf("\n\tneighbor %s", ipaddr_string(bp));
 251                 bp += 4; len -= 4;
 252         }
 253         return (0);
 254 trunc:
 255         return (-1);
 256 }
 257
 258 static int
 259 print_neighbors(register const u_char *bp, register const u_char *ep,
 260     register u_int len)
 261 {
 262         const u_char *laddr;
 263         register u_char metric;
 264         register u_char thresh;
 265         register int ncount;
 266
 267         while (len > 0 && bp < ep) {
 268                 TCHECK2(bp[0], 7);
 269                 laddr = bp;
 270                 bp += 4;
 271                 metric = *bp++;
 272                 thresh = *bp++;
 273                 ncount = *bp++;
 274                 len -= 7;
 275                 while (--ncount >= 0) {
 276                         TCHECK2(bp[0], 4);
 277                         printf(" [%s ->", ipaddr_string(laddr));
 278                         printf(" %s, (%d/%d)]",
 279                                    ipaddr_string(bp), metric, thresh);
 280                         bp += 4;
 281                         len -= 4;
 282                 }
 283         }
 284         return (0);
 285 trunc:
 286         return (-1);
 287 }
 288
 289 static int
 290 print_neighbors2(register const u_char *bp, register const u_char *ep,
 291     register u_int len)
 292 {
 293         const u_char *laddr;
 294         register u_char metric, thresh, flags;
 295         register int ncount;
 296
 297         printf(" (v %d.%d):",
 298                (int)target_level & 0xff,
 299                (int)(target_level >> 8) & 0xff);
 300
 301         while (len > 0 && bp < ep) {
 302                 TCHECK2(bp[0], 8);
 303                 laddr = bp;
 304                 bp += 4;
 305                 metric = *bp++;
 306                 thresh = *bp++;
 307                 flags = *bp++;
 308                 ncount = *bp++;
 309                 len -= 8;
 310                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 311                         printf(" [%s -> ", ipaddr_string(laddr));
 312                         printf("%s (%d/%d", ipaddr_string(bp),
 313                                      metric, thresh);
 314                         if (flags & DVMRP_NF_TUNNEL)
 315                                 printf("/tunnel");
 316                         if (flags & DVMRP_NF_SRCRT)
 317                                 printf("/srcrt");
 318                         if (flags & DVMRP_NF_QUERIER)
 319                                 printf("/querier");
 320                         if (flags & DVMRP_NF_DISABLED)
 321                                 printf("/disabled");
 322                         if (flags & DVMRP_NF_DOWN)
 323                                 printf("/down");
 324                         printf(")]");
 325                         bp += 4;
 326                         len -= 4;
 327                 }
 328                 if (ncount != -1) {
 329                         printf(" [|]");
 330                         return (0);
 331                 }
 332         }
 333         return (0);
 334 trunc:
 335         return (-1);
 336 }
 337
 338 static int
 339 print_prune(register const u_char *bp)
 340 {
 341         TCHECK2(bp[0], 12);
 342         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 343         bp += 8;
 344         (void)printf(" timer ");
 345         relts_print(EXTRACT_32BITS(bp));
 346         return (0);
 347 trunc:
 348         return (-1);
 349 }
 350
 351 static int
 352 print_graft(register const u_char *bp)
 353 {
 354         TCHECK2(bp[0], 8);
 355         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 356         return (0);
 357 trunc:
 358         return (-1);
 359 }
 360
 361 static int
 362 print_graft_ack(register const u_char *bp)
 363 {
 364         TCHECK2(bp[0], 8);
 365         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 366         return (0);
 367 trunc:
 368         return (-1);
 369 }