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 #define NETDISSECT_REWORKED
  23 #ifdef HAVE_CONFIG_H
  24 #include "config.h"
  25 #endif
  26
  27 #include <tcpdump-stdinc.h>
  28
  29 #include "interface.h"
  30 #include "extract.h"
  31 #include "addrtoname.h"
  32
  33 /*
  34  * DVMRP message types and flag values shamelessly stolen from
  35  * mrouted/dvmrp.h.
  36  */
  37 #define DVMRP_PROBE             1       /* for finding neighbors */
  38 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  39 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  40                                         /* of this router's neighbors */
  41 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  42 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  43 #define DVMRP_NEIGHBORS2        6
  44 #define DVMRP_PRUNE             7       /* prune message */
  45 #define DVMRP_GRAFT             8       /* graft message */
  46 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  47
  48 /*
  49  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  50  */
  51 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  52 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  53 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  54 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  55 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  56
  57 static int print_probe(netdissect_options *, const u_char *, const u_char *, u_int);
  58 static int print_report(netdissect_options *, const u_char *, const u_char *, u_int);
  59 static int print_neighbors(netdissect_options *, const u_char *, const u_char *, u_int);
  60 static int print_neighbors2(netdissect_options *, const u_char *, const u_char *, u_int);
  61 static int print_prune(netdissect_options *, const u_char *);
  62 static int print_graft(netdissect_options *, const u_char *);
  63 static int print_graft_ack(netdissect_options *, const u_char *);
  64
  65 static uint32_t target_level;
  66
  67 void
  68 dvmrp_print(netdissect_options *ndo,
  69             register const u_char *bp, register u_int len)
  70 {
  71         register const u_char *ep;
  72         register u_char type;
  73
  74         ep = (const u_char *)ndo->ndo_snapend;
  75         if (bp >= ep)
  76                 return;
  77
  78         ND_TCHECK(bp[1]);
  79         type = bp[1];
  80
  81         /* Skip IGMP header */
  82         bp += 8;
  83         len -= 8;
  84
  85         switch (type) {
  86
  87         case DVMRP_PROBE:
  88                 ND_PRINT((ndo, " Probe"));
  89                 if (ndo->ndo_vflag) {
  90                         if (print_probe(ndo, bp, ep, len) < 0)
  91                                 goto trunc;
  92                 }
  93                 break;
  94
  95         case DVMRP_REPORT:
  96                 ND_PRINT((ndo, " Report"));
  97                 if (ndo->ndo_vflag > 1) {
  98                         if (print_report(ndo, bp, ep, len) < 0)
  99                                 goto trunc;
 100                 }
 101                 break;
 102
 103         case DVMRP_ASK_NEIGHBORS:
 104                 ND_PRINT((ndo, " Ask-neighbors(old)"));
 105                 break;
 106
 107         case DVMRP_NEIGHBORS:
 108                 ND_PRINT((ndo, " Neighbors(old)"));
 109                 if (print_neighbors(ndo, bp, ep, len) < 0)
 110                         goto trunc;
 111                 break;
 112
 113         case DVMRP_ASK_NEIGHBORS2:
 114                 ND_PRINT((ndo, " Ask-neighbors2"));
 115                 break;
 116
 117         case DVMRP_NEIGHBORS2:
 118                 ND_PRINT((ndo, " Neighbors2"));
 119                 /*
 120                  * extract version and capabilities from IGMP group
 121                  * address field
 122                  */
 123                 bp -= 4;
 124                 ND_TCHECK2(bp[0], 4);
 125                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 126                     (bp[2] << 8) | bp[3];
 127                 bp += 4;
 128                 if (print_neighbors2(ndo, bp, ep, len) < 0)
 129                         goto trunc;
 130                 break;
 131
 132         case DVMRP_PRUNE:
 133                 ND_PRINT((ndo, " Prune"));
 134                 if (print_prune(ndo, bp) < 0)
 135                         goto trunc;
 136                 break;
 137
 138         case DVMRP_GRAFT:
 139                 ND_PRINT((ndo, " Graft"));
 140                 if (print_graft(ndo, bp) < 0)
 141                         goto trunc;
 142                 break;
 143
 144         case DVMRP_GRAFT_ACK:
 145                 ND_PRINT((ndo, " Graft-ACK"));
 146                 if (print_graft_ack(ndo, bp) < 0)
 147                         goto trunc;
 148                 break;
 149
 150         default:
 151                 ND_PRINT((ndo, " [type %d]", type));
 152                 break;
 153         }
 154         return;
 155
 156 trunc:
 157         ND_PRINT((ndo, "[|dvmrp]"));
 158         return;
 159 }
 160
 161 static int
 162 print_report(netdissect_options *ndo,
 163              register const u_char *bp, register const u_char *ep,
 164              register u_int len)
 165 {
 166         register uint32_t mask, origin;
 167         register int metric, done;
 168         register u_int i, width;
 169
 170         while (len > 0) {
 171                 if (len < 3) {
 172                         ND_PRINT((ndo, " [|]"));
 173                         return (0);
 174                 }
 175                 ND_TCHECK2(bp[0], 3);
 176                 mask = (uint32_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                 ND_PRINT((ndo, "\n\tMask %s", intoa(htonl(mask))));
 186                 bp += 3;
 187                 len -= 3;
 188                 do {
 189                         if (bp + width + 1 > ep) {
 190                                 ND_PRINT((ndo, " [|]"));
 191                                 return (0);
 192                         }
 193                         if (len < width + 1) {
 194                                 ND_PRINT((ndo, "\n\t  [Truncated Report]"));
 195                                 return (0);
 196                         }
 197                         origin = 0;
 198                         for (i = 0; i < width; ++i) {
 199                                 ND_TCHECK(*bp);
 200                                 origin = origin << 8 | *bp++;
 201                         }
 202                         for ( ; i < 4; ++i)
 203                                 origin <<= 8;
 204
 205                         ND_TCHECK(*bp);
 206                         metric = *bp++;
 207                         done = metric & 0x80;
 208                         metric &= 0x7f;
 209                         ND_PRINT((ndo, "\n\t  %s metric %d", intoa(htonl(origin)),
 210                                 metric));
 211                         len -= width + 1;
 212                 } while (!done);
 213         }
 214         return (0);
 215 trunc:
 216         return (-1);
 217 }
 218
 219 static int
 220 print_probe(netdissect_options *ndo,
 221             register const u_char *bp, register const u_char *ep,
 222             register u_int len)
 223 {
 224         register uint32_t genid;
 225
 226         ND_TCHECK2(bp[0], 4);
 227         if ((len < 4) || ((bp + 4) > ep)) {
 228                 /* { (ctags) */
 229                 ND_PRINT((ndo, " [|}"));
 230                 return (0);
 231         }
 232         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 233         bp += 4;
 234         len -= 4;
 235         ND_PRINT((ndo, ndo->ndo_vflag > 1 ? "\n\t" : " "));
 236         ND_PRINT((ndo, "genid %u", genid));
 237         if (ndo->ndo_vflag < 2)
 238                 return (0);
 239
 240         while ((len > 0) && (bp < ep)) {
 241                 ND_TCHECK2(bp[0], 4);
 242                 ND_PRINT((ndo, "\n\tneighbor %s", ipaddr_string(ndo, bp)));
 243                 bp += 4; len -= 4;
 244         }
 245         return (0);
 246 trunc:
 247         return (-1);
 248 }
 249
 250 static int
 251 print_neighbors(netdissect_options *ndo,
 252                 register const u_char *bp, register const u_char *ep,
 253                 register u_int len)
 254 {
 255         const u_char *laddr;
 256         register u_char metric;
 257         register u_char thresh;
 258         register int ncount;
 259
 260         while (len > 0 && bp < ep) {
 261                 ND_TCHECK2(bp[0], 7);
 262                 laddr = bp;
 263                 bp += 4;
 264                 metric = *bp++;
 265                 thresh = *bp++;
 266                 ncount = *bp++;
 267                 len -= 7;
 268                 while (--ncount >= 0) {
 269                         ND_TCHECK2(bp[0], 4);
 270                         ND_PRINT((ndo, " [%s ->", ipaddr_string(ndo, laddr)));
 271                         ND_PRINT((ndo, " %s, (%d/%d)]",
 272                                    ipaddr_string(ndo, bp), metric, thresh));
 273                         bp += 4;
 274                         len -= 4;
 275                 }
 276         }
 277         return (0);
 278 trunc:
 279         return (-1);
 280 }
 281
 282 static int
 283 print_neighbors2(netdissect_options *ndo,
 284                  register const u_char *bp, register const u_char *ep,
 285                  register u_int len)
 286 {
 287         const u_char *laddr;
 288         register u_char metric, thresh, flags;
 289         register int ncount;
 290
 291         ND_PRINT((ndo, " (v %d.%d):",
 292                (int)target_level & 0xff,
 293                (int)(target_level >> 8) & 0xff));
 294
 295         while (len > 0 && bp < ep) {
 296                 ND_TCHECK2(bp[0], 8);
 297                 laddr = bp;
 298                 bp += 4;
 299                 metric = *bp++;
 300                 thresh = *bp++;
 301                 flags = *bp++;
 302                 ncount = *bp++;
 303                 len -= 8;
 304                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 305                         ND_PRINT((ndo, " [%s -> ", ipaddr_string(ndo, laddr)));
 306                         ND_PRINT((ndo, "%s (%d/%d", ipaddr_string(ndo, bp),
 307                                      metric, thresh));
 308                         if (flags & DVMRP_NF_TUNNEL)
 309                                 ND_PRINT((ndo, "/tunnel"));
 310                         if (flags & DVMRP_NF_SRCRT)
 311                                 ND_PRINT((ndo, "/srcrt"));
 312                         if (flags & DVMRP_NF_QUERIER)
 313                                 ND_PRINT((ndo, "/querier"));
 314                         if (flags & DVMRP_NF_DISABLED)
 315                                 ND_PRINT((ndo, "/disabled"));
 316                         if (flags & DVMRP_NF_DOWN)
 317                                 ND_PRINT((ndo, "/down"));
 318                         ND_PRINT((ndo, ")]"));
 319                         bp += 4;
 320                         len -= 4;
 321                 }
 322                 if (ncount != -1) {
 323                         ND_PRINT((ndo, " [|]"));
 324                         return (0);
 325                 }
 326         }
 327         return (0);
 328 trunc:
 329         return (-1);
 330 }
 331
 332 static int
 333 print_prune(netdissect_options *ndo,
 334             register const u_char *bp)
 335 {
 336         ND_TCHECK2(bp[0], 12);
 337         ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
 338         bp += 8;
 339         ND_PRINT((ndo, " timer "));
 340         relts_print(ndo, EXTRACT_32BITS(bp));
 341         return (0);
 342 trunc:
 343         return (-1);
 344 }
 345
 346 static int
 347 print_graft(netdissect_options *ndo,
 348             register const u_char *bp)
 349 {
 350         ND_TCHECK2(bp[0], 8);
 351         ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
 352         return (0);
 353 trunc:
 354         return (-1);
 355 }
 356
 357 static int
 358 print_graft_ack(netdissect_options *ndo,
 359                 register const u_char *bp)
 360 {
 361         ND_TCHECK2(bp[0], 8);
 362         ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
 363         return (0);
 364 trunc:
 365         return (-1);
 366 }