contrib/tcpdump/print-frag6.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994
   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 /* \summary: IPv6 fragmentation header printer */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include "netdissect-stdinc.h"
  29
  30 #include "netdissect.h"
  31 #include "extract.h"
  32
  33 #include "ip6.h"
  34
  35 int
  36 frag6_print(netdissect_options *ndo, const u_char *bp, const u_char *bp2)
  37 {
  38         const struct ip6_frag *dp;
  39         const struct ip6_hdr *ip6;
  40
  41         ndo->ndo_protocol = "frag6";
  42         dp = (const struct ip6_frag *)bp;
  43         ip6 = (const struct ip6_hdr *)bp2;
  44
  45         if (ndo->ndo_vflag) {
  46                 ND_PRINT("frag (0x%08x:%u|%zu)",
  47                          GET_BE_U_4(dp->ip6f_ident),
  48                          GET_BE_U_2(dp->ip6f_offlg) & IP6F_OFF_MASK,
  49                          sizeof(struct ip6_hdr) + GET_BE_U_2(ip6->ip6_plen) -
  50                                 (bp - bp2) - sizeof(struct ip6_frag));
  51         } else {
  52                 ND_PRINT("frag (%u|%zu)",
  53                          GET_BE_U_2(dp->ip6f_offlg) & IP6F_OFF_MASK,
  54                          sizeof(struct ip6_hdr) + GET_BE_U_2(ip6->ip6_plen) -
  55                                  (bp - bp2) - sizeof(struct ip6_frag));
  56         }
  57
  58         /* it is meaningless to decode non-first fragment */
  59         if ((GET_BE_U_2(dp->ip6f_offlg) & IP6F_OFF_MASK) != 0)
  60                 return -1;
  61         else
  62         {
  63                 ND_PRINT(" ");
  64                 return sizeof(struct ip6_frag);
  65         }
  66 }