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 <tcpdump-stdinc.h>
  27
  28 #include <stdio.h>
  29 #include <string.h>
  30 #include <stdlib.h>
  31
  32 #include "interface.h"
  33 #include "extract.h"
  34 #include "addrtoname.h"
  35
  36 /*
  37  * DVMRP message types and flag values shamelessly stolen from
  38  * mrouted/dvmrp.h.
  39  */
  40 #define DVMRP_PROBE             1       /* for finding neighbors */
  41 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  42 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  43                                         /* of this router's neighbors */
  44 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  45 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  46 #define DVMRP_NEIGHBORS2        6
  47 #define DVMRP_PRUNE             7       /* prune message */
  48 #define DVMRP_GRAFT             8       /* graft message */
  49 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  50
  51 /*
  52  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  53  */
  54 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  55 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  56 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  57 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  58 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  59
  60 static int print_probe(const u_char *, const u_char *, u_int);
  61 static int print_report(const u_char *, const u_char *, u_int);
  62 static int print_neighbors(const u_char *, const u_char *, u_int);
  63 static int print_neighbors2(const u_char *, const u_char *, u_int);
  64 static int print_prune(const u_char *);
  65 static int print_graft(const u_char *);
  66 static int print_graft_ack(const u_char *);
  67
  68 static u_int32_t target_level;
  69
  70 void
  71 dvmrp_print(register const u_char *bp, register u_int len)
  72 {
  73         register const u_char *ep;
  74         register u_char type;
  75
  76         ep = (const u_char *)snapend;
  77         if (bp >= ep)
  78                 return;
  79
  80         TCHECK(bp[1]);
  81         type = bp[1];
  82
  83         /* Skip IGMP header */
  84         bp += 8;
  85         len -= 8;
  86
  87         switch (type) {
  88
  89         case DVMRP_PROBE:
  90                 printf(" Probe");
  91                 if (vflag) {
  92                         if (print_probe(bp, ep, len) < 0)
  93                                 goto trunc;
  94                 }
  95                 break;
  96
  97         case DVMRP_REPORT:
  98                 printf(" Report");
  99                 if (vflag > 1) {
 100                         if (print_report(bp, ep, len) < 0)
 101                                 goto trunc;
 102                 }
 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                 if (print_neighbors(bp, ep, len) < 0)
 112                         goto trunc;
 113                 break;
 114
 115         case DVMRP_ASK_NEIGHBORS2:
 116                 printf(" Ask-neighbors2");
 117                 break;
 118
 119         case DVMRP_NEIGHBORS2:
 120                 printf(" Neighbors2");
 121                 /*
 122                  * extract version and capabilities from IGMP group
 123                  * address field
 124                  */
 125                 bp -= 4;
 126                 TCHECK2(bp[0], 4);
 127                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 128                     (bp[2] << 8) | bp[3];
 129                 bp += 4;
 130                 if (print_neighbors2(bp, ep, len) < 0)
 131                         goto trunc;
 132                 break;
 133
 134         case DVMRP_PRUNE:
 135                 printf(" Prune");
 136                 if (print_prune(bp) < 0)
 137                         goto trunc;
 138                 break;
 139
 140         case DVMRP_GRAFT:
 141                 printf(" Graft");
 142                 if (print_graft(bp) < 0)
 143                         goto trunc;
 144                 break;
 145
 146         case DVMRP_GRAFT_ACK:
 147                 printf(" Graft-ACK");
 148                 if (print_graft_ack(bp) < 0)
 149                         goto trunc;
 150                 break;
 151
 152         default:
 153                 printf(" [type %d]", type);
 154                 break;
 155         }
 156         return;
 157
 158 trunc:
 159         printf("[|dvmrp]");
 160         return;
 161 }
 162
 163 static int
 164 print_report(register const u_char *bp, register const u_char *ep,
 165     register u_int len)
 166 {
 167         register u_int32_t mask, origin;
 168         register int metric, done;
 169         register u_int i, width;
 170
 171         while (len > 0) {
 172                 if (len < 3) {
 173                         printf(" [|]");
 174                         return (0);
 175                 }
 176                 TCHECK2(bp[0], 3);
 177                 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 178                 width = 1;
 179                 if (bp[0])
 180                         width = 2;
 181                 if (bp[1])
 182                         width = 3;
 183                 if (bp[2])
 184                         width = 4;
 185
 186                 printf("\n\tMask %s", intoa(htonl(mask)));
 187                 bp += 3;
 188                 len -= 3;
 189                 do {
 190                         if (bp + width + 1 > ep) {
 191                                 printf(" [|]");
 192                                 return (0);
 193                         }
 194                         if (len < width + 1) {
 195                                 printf("\n\t  [Truncated Report]");
 196                                 return (0);
 197                         }
 198                         origin = 0;
 199                         for (i = 0; i < width; ++i) {
 200                                 TCHECK(*bp);
 201                                 origin = origin << 8 | *bp++;
 202                         }
 203                         for ( ; i < 4; ++i)
 204                                 origin <<= 8;
 205
 206                         TCHECK(*bp);
 207                         metric = *bp++;
 208                         done = metric & 0x80;
 209                         metric &= 0x7f;
 210                         printf("\n\t  %s metric %d", intoa(htonl(origin)),
 211                                 metric);
 212                         len -= width + 1;
 213                 } while (!done);
 214         }
 215         return (0);
 216 trunc:
 217         return (-1);
 218 }
 219
 220 static int
 221 print_probe(register const u_char *bp, register const u_char *ep,
 222     register u_int len)
 223 {
 224         register u_int32_t genid;
 225
 226         TCHECK2(bp[0], 4);
 227         if ((len < 4) || ((bp + 4) > ep)) {
 228                 /* { (ctags) */
 229                 printf(" [|}");
 230                 return (0);
 231         }
 232         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 233         bp += 4;
 234         len -= 4;
 235         if (vflag > 1)
 236                 printf("\n\t");
 237         else
 238                 printf(" ");
 239         printf("genid %u", genid);
 240         if (vflag < 2)
 241                 return (0);
 242
 243         while ((len > 0) && (bp < ep)) {
 244                 TCHECK2(bp[0], 4);
 245                 printf("\n\tneighbor %s", ipaddr_string(bp));
 246                 bp += 4; len -= 4;
 247         }
 248         return (0);
 249 trunc:
 250         return (-1);
 251 }
 252
 253 static int
 254 print_neighbors(register const u_char *bp, register const u_char *ep,
 255     register u_int len)
 256 {
 257         const u_char *laddr;
 258         register u_char metric;
 259         register u_char thresh;
 260         register int ncount;
 261
 262         while (len > 0 && bp < ep) {
 263                 TCHECK2(bp[0], 7);
 264                 laddr = bp;
 265                 bp += 4;
 266                 metric = *bp++;
 267                 thresh = *bp++;
 268                 ncount = *bp++;
 269                 len -= 7;
 270                 while (--ncount >= 0) {
 271                         TCHECK2(bp[0], 4);
 272                         printf(" [%s ->", ipaddr_string(laddr));
 273                         printf(" %s, (%d/%d)]",
 274                                    ipaddr_string(bp), metric, thresh);
 275                         bp += 4;
 276                         len -= 4;
 277                 }
 278         }
 279         return (0);
 280 trunc:
 281         return (-1);
 282 }
 283
 284 static int
 285 print_neighbors2(register const u_char *bp, register const u_char *ep,
 286     register u_int len)
 287 {
 288         const u_char *laddr;
 289         register u_char metric, thresh, flags;
 290         register int ncount;
 291
 292         printf(" (v %d.%d):",
 293                (int)target_level & 0xff,
 294                (int)(target_level >> 8) & 0xff);
 295
 296         while (len > 0 && bp < ep) {
 297                 TCHECK2(bp[0], 8);
 298                 laddr = bp;
 299                 bp += 4;
 300                 metric = *bp++;
 301                 thresh = *bp++;
 302                 flags = *bp++;
 303                 ncount = *bp++;
 304                 len -= 8;
 305                 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
 306                         printf(" [%s -> ", ipaddr_string(laddr));
 307                         printf("%s (%d/%d", ipaddr_string(bp),
 308                                      metric, thresh);
 309                         if (flags & DVMRP_NF_TUNNEL)
 310                                 printf("/tunnel");
 311                         if (flags & DVMRP_NF_SRCRT)
 312                                 printf("/srcrt");
 313                         if (flags & DVMRP_NF_QUERIER)
 314                                 printf("/querier");
 315                         if (flags & DVMRP_NF_DISABLED)
 316                                 printf("/disabled");
 317                         if (flags & DVMRP_NF_DOWN)
 318                                 printf("/down");
 319                         printf(")]");
 320                         bp += 4;
 321                         len -= 4;
 322                 }
 323                 if (ncount != -1) {
 324                         printf(" [|]");
 325                         return (0);
 326                 }
 327         }
 328         return (0);
 329 trunc:
 330         return (-1);
 331 }
 332
 333 static int
 334 print_prune(register const u_char *bp)
 335 {
 336         TCHECK2(bp[0], 12);
 337         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 338         bp += 8;
 339         (void)printf(" timer ");
 340         relts_print(EXTRACT_32BITS(bp));
 341         return (0);
 342 trunc:
 343         return (-1);
 344 }
 345
 346 static int
 347 print_graft(register const u_char *bp)
 348 {
 349         TCHECK2(bp[0], 8);
 350         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 351         return (0);
 352 trunc:
 353         return (-1);
 354 }
 355
 356 static int
 357 print_graft_ack(register const u_char *bp)
 358 {
 359         TCHECK2(bp[0], 8);
 360         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 361         return (0);
 362 trunc:
 363         return (-1);
 364 }