xref: /minix3/external/bsd/tcpdump/dist/print-ipcomp.c (revision 03ac74ede908465cc64c671bbd209e761dc765dc)
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 }
89