external/bsd/tcpdump/dist/print-ipcomp.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 #include <sys/cdefs.h>
  23 #ifndef lint
  24 __RCSID("$NetBSD: print-ipcomp.c,v 1.4 2014/11/20 03:05:03 christos Exp $");
  25 #endif
  26
  27 #define NETDISSECT_REWORKED
  28 #ifdef HAVE_CONFIG_H
  29 #include "config.h"
  30 #endif
  31
  32 #include <tcpdump-stdinc.h>
  33
  34 struct ipcomp {
  35         uint8_t comp_nxt;       /* Next Header */
  36         uint8_t comp_flags;     /* Length of data, in 32bit */
  37         uint16_t comp_cpi;      /* Compression parameter index */
  38 };
  39
  40 #if defined(HAVE_LIBZ) && defined(HAVE_ZLIB_H)
  41 #include <zlib.h>
  42 #endif
  43
  44 #include "interface.h"
  45 #include "extract.h"
  46
  47 int
  48 ipcomp_print(netdissect_options *ndo, register const u_char *bp, int *nhdr _U_)
  49 {
  50         register const struct ipcomp *ipcomp;
  51         register const u_char *ep;
  52         uint16_t cpi;
  53 #if defined(HAVE_LIBZ) && defined(HAVE_ZLIB_H)
  54         int advance;
  55 #endif
  56
  57         ipcomp = (struct ipcomp *)bp;
  58         cpi = EXTRACT_16BITS(&ipcomp->comp_cpi);
  59
  60         /* 'ep' points to the end of available data. */
  61         ep = ndo->ndo_snapend;
  62
  63         if ((u_char *)(ipcomp + 1) >= ep - sizeof(struct ipcomp)) {
  64                 ND_PRINT((ndo, "[|IPCOMP]"));
  65                 goto fail;
  66         }
  67         ND_PRINT((ndo, "IPComp(cpi=0x%04x)", cpi));
  68
  69 #if defined(HAVE_LIBZ) && defined(HAVE_ZLIB_H)
  70         if (1)
  71                 goto fail;
  72
  73         /*
  74          * We may want to decompress the packet here.  Packet buffer
  75          * management is a headache (if we decompress, packet will become
  76          * larger).
  77          */
  78         if (nhdr)
  79                 *nhdr = ipcomp->comp_nxt;
  80         advance = sizeof(struct ipcomp);
  81
  82         ND_PRINT((ndo, ": "));
  83         return advance;
  84
  85 #endif
  86 fail:
  87         return -1;
  88 }