xref: /freebsd/contrib/tcpdump/print-ipcomp.c (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
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[] =
24     "@(#) $Header: /tcpdump/master/tcpdump/print-ipcomp.c,v 1.13 2000/12/12 09:58:41 itojun Exp $";
25 #endif
26 
27 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30 
31 #include <string.h>
32 #include <sys/param.h>
33 #include <sys/time.h>
34 #include <sys/types.h>
35 #include <sys/socket.h>
36 
37 #include <netinet/in.h>
38 
39 #include <stdio.h>
40 
41 struct ipcomp {
42 	u_int8_t comp_nxt;	/* Next Header */
43 	u_int8_t comp_flags;	/* Length of data, in 32bit */
44 	u_int16_t comp_cpi;	/* Compression parameter index */
45 };
46 
47 #if defined(HAVE_LIBZ) && defined(HAVE_ZLIB_H)
48 #include <zlib.h>
49 #endif
50 
51 #include "interface.h"
52 #include "addrtoname.h"
53 
54 int
55 ipcomp_print(register const u_char *bp, register const u_char *bp2, int *nhdr)
56 {
57 	register const struct ipcomp *ipcomp;
58 	register const u_char *ep;
59 	u_int16_t cpi;
60 #if defined(HAVE_LIBZ) && defined(HAVE_ZLIB_H)
61 	int advance;
62 #endif
63 
64 	ipcomp = (struct ipcomp *)bp;
65 	cpi = (u_int16_t)ntohs(ipcomp->comp_cpi);
66 
67 	/* 'ep' points to the end of available data. */
68 	ep = snapend;
69 
70 	if ((u_char *)(ipcomp + 1) >= ep - sizeof(struct ipcomp)) {
71 		fputs("[|IPCOMP]", stdout);
72 		goto fail;
73 	}
74 	printf("IPComp(cpi=0x%04x)", cpi);
75 
76 #if defined(HAVE_LIBZ) && defined(HAVE_ZLIB_H)
77 	if (1)
78 		goto fail;
79 
80 	/*
81 	 * We may want to decompress the packet here.  Packet buffer
82 	 * management is a headache (if we decompress, packet will become
83 	 * larger).
84 	 */
85 	if (nhdr)
86 		*nhdr = ipcomp->comp_nxt;
87 	advance = sizeof(struct ipcomp);
88 
89 	printf(": ");
90 	return advance;
91 
92 #endif
93 fail:
94 	if (nhdr)
95 		*nhdr = -1;
96 	return 65536;
97 }
98