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 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 #include <netdissect-stdinc.h>
  27
  28 #include "netdissect.h"
  29 #include "extract.h"
  30 #include "addrtoname.h"
  31
  32 /*
  33  * DVMRP message types and flag values shamelessly stolen from
  34  * mrouted/dvmrp.h.
  35  */
  36 #define DVMRP_PROBE             1       /* for finding neighbors */
  37 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  38 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  39                                         /* of this router's neighbors */
  40 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  41 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  42 #define DVMRP_NEIGHBORS2        6
  43 #define DVMRP_PRUNE             7       /* prune message */
  44 #define DVMRP_GRAFT             8       /* graft message */
  45 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  46
  47 /*
  48  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  49  */
  50 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  51 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  52 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  53 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  54 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  55
  56 static int print_probe(netdissect_options *, const u_char *, const u_char *, u_int);
  57 static int print_report(netdissect_options *, const u_char *, const u_char *, u_int);
  58 static int print_neighbors(netdissect_options *, const u_char *, const u_char *, u_int);
  59 static int print_neighbors2(netdissect_options *, const u_char *, const u_char *, u_int);
  60 static int print_prune(netdissect_options *, const u_char *);
  61 static int print_graft(netdissect_options *, const u_char *);
  62 static int print_graft_ack(netdissect_options *, const u_char *);
  63
  64 static uint32_t target_level;
  65
  66 void
  67 dvmrp_print(netdissect_options *ndo,
  68             register const u_char *bp, register u_int len)
  69 {
  70         register const u_char *ep;
  71         register u_char type;
  72
  73         ep = (const u_char *)ndo->ndo_snapend;
  74         if (bp >= ep)
  75                 return;
  76
  77         ND_TCHECK(bp[1]);
  78         type = bp[1];
  79
  80         /* Skip IGMP header */
  81         bp += 8;
  82         len -= 8;
  83
  84         switch (type) {
  85
  86         case DVMRP_PROBE:
  87                 ND_PRINT((ndo, " Probe"));
  88                 if (ndo->ndo_vflag) {
  89                         if (print_probe(ndo, bp, ep, len) < 0)
  90                                 goto trunc;
  91                 }
  92                 break;
  93
  94         case DVMRP_REPORT:
  95                 ND_PRINT((ndo, " Report"));
  96                 if (ndo->ndo_vflag > 1) {
  97                         if (print_report(ndo, bp, ep, len) < 0)
  98                                 goto trunc;
  99                 }
 100                 break;
 101
 102         case DVMRP_ASK_NEIGHBORS:
 103                 ND_PRINT((ndo, " Ask-neighbors(old)"));
 104                 break;
 105
 106         case DVMRP_NEIGHBORS:
 107                 ND_PRINT((ndo, " Neighbors(old)"));
 108                 if (print_neighbors(ndo, bp, ep, len) < 0)
 109                         goto trunc;
 110                 break;
 111
 112         case DVMRP_ASK_NEIGHBORS2:
 113                 ND_PRINT((ndo, " Ask-neighbors2"));
 114                 break;
 115
 116         case DVMRP_NEIGHBORS2:
 117                 ND_PRINT((ndo, " Neighbors2"));
 118                 /*
 119                  * extract version and capabilities from IGMP group
 120                  * address field
 121                  */
 122                 bp -= 4;
 123                 ND_TCHECK2(bp[0], 4);
 124                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 125                     (bp[2] << 8) | bp[3];
 126                 bp += 4;
 127                 if (print_neighbors2(ndo, bp, ep, len) < 0)
 128                         goto trunc;
 129                 break;
 130
 131         case DVMRP_PRUNE:
 132                 ND_PRINT((ndo, " Prune"));
 133                 if (print_prune(ndo, bp) < 0)
 134                         goto trunc;
 135                 break;
 136
 137         case DVMRP_GRAFT:
 138                 ND_PRINT((ndo, " Graft"));
 139                 if (print_graft(ndo, bp) < 0)
 140                         goto trunc;
 141                 break;
 142
 143         case DVMRP_GRAFT_ACK:
 144                 ND_PRINT((ndo, " Graft-ACK"));
 145                 if (print_graft_ack(ndo, bp) < 0)
 146                         goto trunc;
 147                 break;
 148
 149         default:
 150                 ND_PRINT((ndo, " [type %d]", type));
 151                 break;
 152         }
 153         return;
 154
 155 trunc:
 156         ND_PRINT((ndo, "[|dvmrp]"));
 157         return;
 158 }
 159
 160 static int
 161 print_report(netdissect_options *ndo,
 162              register const u_char *bp, register const u_char *ep,
 163              register u_int len)
 164 {
 165         register uint32_t mask, origin;
 166         register int metric, done;
 167         register u_int i, width;
 168
 169         while (len > 0) {
 170                 if (len < 3) {
 171                         ND_PRINT((ndo, " [|]"));
 172                         return (0);
 173                 }
 174                 ND_TCHECK2(bp[0], 3);
 175                 mask = (uint32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 176                 width = 1;
 177                 if (bp[0])
 178                         width = 2;
 179                 if (bp[1])
 180                         width = 3;
 181                 if (bp[2])
 182                         width = 4;
 183
 184                 ND_PRINT((ndo, "\n\tMask %s", intoa(htonl(mask))));
 185                 bp += 3;
 186                 len -= 3;
 187                 do {
 188                         if (bp + width + 1 > ep) {
 189                                 ND_PRINT((ndo, " [|]"));
 190                                 return (0);
 191                         }
 192                         if (len < width + 1) {
 193                                 ND_PRINT((ndo, "\n\t  [Truncated Report]"));
 194                                 return (0);
 195                         }
 196                         origin = 0;
 197                         for (i = 0; i < width; ++i) {
 198                                 ND_TCHECK(*bp);
 199                                 origin = origin << 8 | *bp++;
 200                         }
 201                         for ( ; i < 4; ++i)
 202                                 origin <<= 8;
 203
 204                         ND_TCHECK(*bp);
 205                         metric = *bp++;
 206                         done = metric & 0x80;
 207                         metric &= 0x7f;
 208                         ND_PRINT((ndo, "\n\t  %s metric %d", intoa(htonl(origin)),
 209                                 metric));
 210                         len -= width + 1;
 211                 } while (!done);
 212         }
 213         return (0);
 214 trunc:
 215         return (-1);
 216 }
 217
 218 static int
 219 print_probe(netdissect_options *ndo,
 220             register const u_char *bp, register const u_char *ep,
 221             register u_int len)
 222 {
 223         register uint32_t genid;
 224
 225         ND_TCHECK2(bp[0], 4);
 226         if ((len < 4) || ((bp + 4) > ep)) {
 227                 /* { (ctags) */
 228                 ND_PRINT((ndo, " [|}"));
 229                 return (0);
 230         }
 231         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 232         bp += 4;
 233         len -= 4;
 234         ND_PRINT((ndo, ndo->ndo_vflag > 1 ? "\n\t" : " "));
 235         ND_PRINT((ndo, "genid %u", genid));
 236         if (ndo->ndo_vflag < 2)
 237                 return (0);
 238
 239         while ((len > 0) && (bp < ep)) {
 240                 ND_TCHECK2(bp[0], 4);
 241                 ND_PRINT((ndo, "\n\tneighbor %s", ipaddr_string(ndo, bp)));
 242                 bp += 4; len -= 4;
 243         }
 244         return (0);
 245 trunc:
 246         return (-1);
 247 }
 248
 249 static int
 250 print_neighbors(netdissect_options *ndo,
 251                 register const u_char *bp, register const u_char *ep,
 252                 register u_int len)
 253 {
 254         const u_char *laddr;
 255         register u_char metric;
 256         register u_char thresh;
 257         register int ncount;
 258
 259         while (len > 0 && bp < ep) {
 260                 ND_TCHECK2(bp[0], 7);
 261                 laddr = bp;
 262                 bp += 4;
 263                 metric = *bp++;
 264                 thresh = *bp++;
 265                 ncount = *bp++;
 266                 len -= 7;
 267                 while (--ncount >= 0) {
 268                         ND_TCHECK2(bp[0], 4);
 269                         ND_PRINT((ndo, " [%s ->", ipaddr_string(ndo, laddr)));
 270                         ND_PRINT((ndo, " %s, (%d/%d)]",
 271                                    ipaddr_string(ndo, bp), metric, thresh));
 272                         bp += 4;
 273                         len -= 4;
 274                 }
 275         }
 276         return (0);
 277 trunc:
 278         return (-1);
 279 }
 280
 281 static int
 282 print_neighbors2(netdissect_options *ndo,
 283                  register const u_char *bp, register const u_char *ep,
 284                  register u_int len)
 285 {
 286         const u_char *laddr;
 287         register u_char metric, thresh, flags;
 288         register int ncount;
 289
 290         ND_PRINT((ndo, " (v %d.%d):",
 291                (int)target_level & 0xff,
 292                (int)(target_level >> 8) & 0xff));
 293
 294         while (len > 0 && bp < ep) {
 295                 ND_TCHECK2(bp[0], 8);
 296                 laddr = bp;
 297                 bp += 4;
 298                 metric = *bp++;
 299                 thresh = *bp++;
 300                 flags = *bp++;
 301                 ncount = *bp++;
 302                 len -= 8;
 303                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 304                         ND_PRINT((ndo, " [%s -> ", ipaddr_string(ndo, laddr)));
 305                         ND_PRINT((ndo, "%s (%d/%d", ipaddr_string(ndo, bp),
 306                                      metric, thresh));
 307                         if (flags & DVMRP_NF_TUNNEL)
 308                                 ND_PRINT((ndo, "/tunnel"));
 309                         if (flags & DVMRP_NF_SRCRT)
 310                                 ND_PRINT((ndo, "/srcrt"));
 311                         if (flags & DVMRP_NF_QUERIER)
 312                                 ND_PRINT((ndo, "/querier"));
 313                         if (flags & DVMRP_NF_DISABLED)
 314                                 ND_PRINT((ndo, "/disabled"));
 315                         if (flags & DVMRP_NF_DOWN)
 316                                 ND_PRINT((ndo, "/down"));
 317                         ND_PRINT((ndo, ")]"));
 318                         bp += 4;
 319                         len -= 4;
 320                 }
 321                 if (ncount != -1) {
 322                         ND_PRINT((ndo, " [|]"));
 323                         return (0);
 324                 }
 325         }
 326         return (0);
 327 trunc:
 328         return (-1);
 329 }
 330
 331 static int
 332 print_prune(netdissect_options *ndo,
 333             register const u_char *bp)
 334 {
 335         ND_TCHECK2(bp[0], 12);
 336         ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
 337         bp += 8;
 338         ND_PRINT((ndo, " timer "));
 339         relts_print(ndo, EXTRACT_32BITS(bp));
 340         return (0);
 341 trunc:
 342         return (-1);
 343 }
 344
 345 static int
 346 print_graft(netdissect_options *ndo,
 347             register const u_char *bp)
 348 {
 349         ND_TCHECK2(bp[0], 8);
 350         ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
 351         return (0);
 352 trunc:
 353         return (-1);
 354 }
 355
 356 static int
 357 print_graft_ack(netdissect_options *ndo,
 358                 register const u_char *bp)
 359 {
 360         ND_TCHECK2(bp[0], 8);
 361         ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
 362         return (0);
 363 trunc:
 364         return (-1);
 365 }