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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 #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 }
     84