The Tcpdump Group git mirrors - tcpdump/blob - 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 "ip6.h"
  31 #include "netdissect.h"
  32 #include "extract.h"
  33
  34 int
  35 frag6_print(netdissect_options *ndo, register const u_char *bp, register const u_char *bp2)
  36 {
  37         register const struct ip6_frag *dp;
  38         register const struct ip6_hdr *ip6;
  39
  40         dp = (const struct ip6_frag *)bp;
  41         ip6 = (const struct ip6_hdr *)bp2;
  42
  43         ND_TCHECK(dp->ip6f_offlg);
  44
  45         if (ndo->ndo_vflag) {
  46                 ND_PRINT((ndo, "frag (0x%08x:%d|%ld)",
  47                        EXTRACT_32BITS(&dp->ip6f_ident),
  48                        EXTRACT_16BITS(&dp->ip6f_offlg) & IP6F_OFF_MASK,
  49                        sizeof(struct ip6_hdr) + EXTRACT_16BITS(&ip6->ip6_plen) -
  50                                (long)(bp - bp2) - sizeof(struct ip6_frag)));
  51         } else {
  52                 ND_PRINT((ndo, "frag (%d|%ld)",
  53                        EXTRACT_16BITS(&dp->ip6f_offlg) & IP6F_OFF_MASK,
  54                        sizeof(struct ip6_hdr) + EXTRACT_16BITS(&ip6->ip6_plen) -
  55                                (long)(bp - bp2) - sizeof(struct ip6_frag)));
  56         }
  57
  58         /* it is meaningless to decode non-first fragment */
  59         if ((EXTRACT_16BITS(&dp->ip6f_offlg) & IP6F_OFF_MASK) != 0)
  60                 return -1;
  61         else
  62         {
  63                 ND_PRINT((ndo, " "));
  64                 return sizeof(struct ip6_frag);
  65         }
  66 trunc:
  67         ND_PRINT((ndo, "[|frag]"));
  68         return -1;
  69 }