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