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 1.14 1999-10-17 21:37:12 mcr Exp $ (LBL)";
  25 #endif
  26
  27 #include <sys/param.h>
  28 #include <sys/time.h>
  29 #include <sys/socket.h>
  30
  31 #include <netinet/in.h>
  32 #include <netinet/in_systm.h>
  33 #include <netinet/ip.h>
  34 #include <netinet/udp.h>
  35 #include <netinet/tcp.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 "addrtoname.h"
  44
  45 /*
  46  * DVMRP message types and flag values shamelessly stolen from
  47  * mrouted/dvmrp.h.
  48  */
  49 #define DVMRP_PROBE             1       /* for finding neighbors */
  50 #define DVMRP_REPORT            2       /* for reporting some or all routes */
  51 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  52                                         /*
  53                                          * of this router's neighbors
  54                                          */
  55 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  56 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  57 #define DVMRP_NEIGHBORS2        6
  58 #define DVMRP_PRUNE             7       /* prune message */
  59 #define DVMRP_GRAFT             8       /* graft message */
  60 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  61
  62 /*
  63  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
  64  */
  65 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
  66 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
  67 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
  68 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
  69 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
  70
  71 static void print_probe(const u_char *, const u_char *, u_int);
  72 static void print_report(const u_char *, const u_char *, u_int);
  73 static void print_neighbors(const u_char *, const u_char *, u_int);
  74 static void print_neighbors2(const u_char *, const u_char *, u_int);
  75 static void print_prune(const u_char *, const u_char *, u_int);
  76 static void print_graft(const u_char *, const u_char *, u_int);
  77 static void print_graft_ack(const u_char *, const u_char *, u_int);
  78
  79 static u_int32_t target_level;
  80
  81 void
  82 dvmrp_print(register const u_char *bp, register u_int len)
  83 {
  84         register const u_char *ep;
  85         register u_char type;
  86
  87         ep = (const u_char *)snapend;
  88         if (bp >= ep)
  89                 return;
  90
  91         type = bp[1];
  92         bp += 8;
  93         /*
  94          * Skip IGMP header
  95          */
  96
  97         len -= 8;
  98
  99         switch (type) {
 100
 101         case DVMRP_PROBE:
 102                 printf(" Probe");
 103                 if (vflag)
 104                         print_probe(bp, ep, len);
 105                 break;
 106
 107         case DVMRP_REPORT:
 108                 printf(" Report");
 109                 if (vflag)
 110                         print_report(bp, ep, len);
 111                 break;
 112
 113         case DVMRP_ASK_NEIGHBORS:
 114                 printf(" Ask-neighbors(old)");
 115                 break;
 116
 117         case DVMRP_NEIGHBORS:
 118                 printf(" Neighbors(old)");
 119                 print_neighbors(bp, ep, len);
 120                 break;
 121
 122         case DVMRP_ASK_NEIGHBORS2:
 123                 printf(" Ask-neighbors2");
 124                 break;
 125
 126         case DVMRP_NEIGHBORS2:
 127                 printf(" Neighbors2");
 128                 /*
 129                  * extract version and capabilities from IGMP group
 130                  * address field
 131                  */
 132                 bp -= 4;
 133                 target_level = (bp[0] << 24) | (bp[1] << 16) |
 134                     (bp[2] << 8) | bp[3];
 135                 bp += 4;
 136                 print_neighbors2(bp, ep, len);
 137                 break;
 138
 139         case DVMRP_PRUNE:
 140                 printf(" Prune");
 141                 print_prune(bp, ep, len);
 142                 break;
 143
 144         case DVMRP_GRAFT:
 145                 printf(" Graft");
 146                 print_graft(bp, ep, len);
 147                 break;
 148
 149         case DVMRP_GRAFT_ACK:
 150                 printf(" Graft-ACK");
 151                 print_graft_ack(bp, ep, len);
 152                 break;
 153
 154         default:
 155                 printf(" [type %d]", type);
 156                 break;
 157         }
 158 }
 159
 160 static void
 161 print_report(register const u_char *bp, register const u_char *ep,
 162     register u_int len)
 163 {
 164         register u_int32_t mask, origin;
 165         register int metric, i, width, done;
 166
 167         while (len > 0) {
 168                 if (len < 3) {
 169                         printf(" [|]");
 170                         return;
 171                 }
 172                 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
 173                 width = 1;
 174                 if (bp[0])
 175                         width = 2;
 176                 if (bp[1])
 177                         width = 3;
 178                 if (bp[2])
 179                         width = 4;
 180
 181                 printf("\n\tMask %s", intoa(htonl(mask)));
 182                 bp += 3;
 183                 len -= 3;
 184                 do {
 185                         if (bp + width + 1 > ep) {
 186                                 printf(" [|]");
 187                                 return;
 188                         }
 189                         if (len < width + 1) {
 190                                 printf("\n\t  [Truncated Report]");
 191                                 return;
 192                         }
 193                         origin = 0;
 194                         for (i = 0; i < width; ++i)
 195                                 origin = origin << 8 | *bp++;
 196                         for ( ; i < 4; ++i)
 197                                 origin <<= 8;
 198
 199                         metric = *bp++;
 200                         done = metric & 0x80;
 201                         metric &= 0x7f;
 202                         printf("\n\t  %s metric %d", intoa(htonl(origin)),
 203                                 metric);
 204                         len -= width + 1;
 205                 } while (!done);
 206         }
 207 }
 208
 209 #define GET_ADDR(to) (memcpy((char *)to, (char *)bp, 4), bp += 4)
 210
 211 static void
 212 print_probe(register const u_char *bp, register const u_char *ep,
 213     register u_int len)
 214 {
 215         register u_int32_t genid;
 216         u_char neighbor[4];
 217
 218         if ((len < 4) || ((bp + 4) > ep)) {
 219                 /* { (ctags) */
 220                 printf(" [|}");
 221                 return;
 222         }
 223         genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
 224         bp += 4;
 225         len -= 4;
 226         printf("\n\tgenid %u", genid);
 227
 228         while ((len > 0) && (bp < ep)) {
 229                 if ((len < 4) || ((bp + 4) > ep)) {
 230                         printf(" [|]");
 231                         return;
 232                 }
 233                 GET_ADDR(neighbor);
 234                 len -= 4;
 235                 printf("\n\tneighbor %s", ipaddr_string(neighbor));
 236         }
 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         u_char laddr[4], neighbor[4];
 244         register u_char metric;
 245         register u_char thresh;
 246         register int ncount;
 247
 248         while (len > 0 && bp < ep) {
 249                 if (len < 7 || (bp + 7) >= ep) {
 250                         printf(" [|]");
 251                         return;
 252                 }
 253                 GET_ADDR(laddr);
 254                 metric = *bp++;
 255                 thresh = *bp++;
 256                 ncount = *bp++;
 257                 len -= 7;
 258                 while (--ncount >= 0 && (len >= 4) && (bp + 4) < ep) {
 259                         GET_ADDR(neighbor);
 260                         printf(" [%s ->", ipaddr_string(laddr));
 261                         printf(" %s, (%d/%d)]",
 262                                    ipaddr_string(neighbor), metric, thresh);
 263                         len -= 4;
 264                 }
 265         }
 266 }
 267
 268 static void
 269 print_neighbors2(register const u_char *bp, register const u_char *ep,
 270     register u_int len)
 271 {
 272         u_char laddr[4], neighbor[4];
 273         register u_char metric, thresh, flags;
 274         register int ncount;
 275
 276         printf(" (v %d.%d):",
 277                (int)target_level & 0xff,
 278                (int)(target_level >> 8) & 0xff);
 279
 280         while (len > 0 && bp < ep) {
 281                 if (len < 8 || (bp + 8) >= ep) {
 282                         printf(" [|]");
 283                         return;
 284                 }
 285                 GET_ADDR(laddr);
 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                         GET_ADDR(neighbor);
 293                         printf(" [%s -> ", ipaddr_string(laddr));
 294                         printf("%s (%d/%d", ipaddr_string(neighbor),
 295                                      metric, thresh);
 296                         if (flags & DVMRP_NF_TUNNEL)
 297                                 printf("/tunnel");
 298                         if (flags & DVMRP_NF_SRCRT)
 299                                 printf("/srcrt");
 300                         if (flags & DVMRP_NF_QUERIER)
 301                                 printf("/querier");
 302                         if (flags & DVMRP_NF_DISABLED)
 303                                 printf("/disabled");
 304                         if (flags & DVMRP_NF_DOWN)
 305                                 printf("/down");
 306                         printf(")]");
 307                         len -= 4;
 308                 }
 309                 if (ncount != -1) {
 310                         printf(" [|]");
 311                         return;
 312                 }
 313         }
 314 }
 315
 316 static void
 317 print_prune(register const u_char *bp, register const u_char *ep,
 318     register u_int len)
 319 {
 320         union a {
 321                 u_char b[4];
 322                 u_int32_t i;
 323         } prune_timer;
 324
 325         if (len < 12 || (bp + 12) > ep) {
 326                 printf(" [|]");
 327                 return;
 328         }
 329         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 330         bp += 8;
 331         GET_ADDR(prune_timer.b);
 332         printf(" timer %d", (int)ntohl(prune_timer.i));
 333 }
 334
 335 static void
 336 print_graft(register const u_char *bp, register const u_char *ep,
 337     register u_int len)
 338 {
 339
 340         if (len < 8 || (bp + 8) > ep) {
 341                 printf(" [|]");
 342                 return;
 343         }
 344         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 345 }
 346
 347 static void
 348 print_graft_ack(register const u_char *bp, register const u_char *ep,
 349     register u_int len)
 350 {
 351
 352         if (len < 8 || (bp + 8) > ep) {
 353                 printf(" [|]");
 354                 return;
 355         }
 356         printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
 357 }