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      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 #ifndef lint
     23 static const char rcsid[] _U_ =
     24     "@(#) $Header: /tcpdump/master/tcpdump/print-ipcomp.c,v 1.20 2003/11/19 00:36:08 guy Exp $";
     25 #endif
     26 
     27 #ifdef HAVE_CONFIG_H
     28 #include "config.h"
     29 #endif
     30 
     31 #include <string.h>
     32 #include <tcpdump-stdinc.h>
     33 
     34 #include <stdio.h>
     35 
     36 struct ipcomp {
     37 	u_int8_t comp_nxt;	/* Next Header */
     38 	u_int8_t comp_flags;	/* Length of data, in 32bit */
     39 	u_int16_t comp_cpi;	/* Compression parameter index */
     40 };
     41 
     42 #if defined(HAVE_LIBZ) && defined(HAVE_ZLIB_H)
     43 #include <zlib.h>
     44 #endif
     45 
     46 #include "interface.h"
     47 #include "addrtoname.h"
     48 #include "extract.h"
     49 
     50 int
     51 ipcomp_print(register const u_char *bp, int *nhdr _U_)
     52 {
     53 	register const struct ipcomp *ipcomp;
     54 	register const u_char *ep;
     55 	u_int16_t cpi;
     56 #if defined(HAVE_LIBZ) && defined(HAVE_ZLIB_H)
     57 	int advance;
     58 #endif
     59 
     60 	ipcomp = (struct ipcomp *)bp;
     61 	cpi = EXTRACT_16BITS(&ipcomp->comp_cpi);
     62 
     63 	/* 'ep' points to the end of available data. */
     64 	ep = snapend;
     65 
     66 	if ((u_char *)(ipcomp + 1) >= ep - sizeof(struct ipcomp)) {
     67 		fputs("[|IPCOMP]", stdout);
     68 		goto fail;
     69 	}
     70 	printf("IPComp(cpi=0x%04x)", cpi);
     71 
     72 #if defined(HAVE_LIBZ) && defined(HAVE_ZLIB_H)
     73 	if (1)
     74 		goto fail;
     75 
     76 	/*
     77 	 * We may want to decompress the packet here.  Packet buffer
     78 	 * management is a headache (if we decompress, packet will become
     79 	 * larger).
     80 	 */
     81 	if (nhdr)
     82 		*nhdr = ipcomp->comp_nxt;
     83 	advance = sizeof(struct ipcomp);
     84 
     85 	printf(": ");
     86 	return advance;
     87 
     88 #endif
     89 fail:
     90 	return -1;
     91 }
     92