xref: /freebsd/contrib/tcpdump/print-frag6.c (revision 0a7e5f1f02aad2ff5fff1c60f44c6975fd07e1d9)
1b0453382SBill Fenner /*
2b0453382SBill Fenner  * Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994
3b0453382SBill Fenner  *	The Regents of the University of California.  All rights reserved.
4b0453382SBill Fenner  *
5b0453382SBill Fenner  * Redistribution and use in source and binary forms, with or without
6b0453382SBill Fenner  * modification, are permitted provided that: (1) source code distributions
7b0453382SBill Fenner  * retain the above copyright notice and this paragraph in its entirety, (2)
8b0453382SBill Fenner  * distributions including binary code include the above copyright notice and
9b0453382SBill Fenner  * this paragraph in its entirety in the documentation or other materials
10b0453382SBill Fenner  * provided with the distribution, and (3) all advertising materials mentioning
11b0453382SBill Fenner  * features or use of this software display the following acknowledgement:
12b0453382SBill Fenner  * ``This product includes software developed by the University of California,
13b0453382SBill Fenner  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14b0453382SBill Fenner  * the University nor the names of its contributors may be used to endorse
15b0453382SBill Fenner  * or promote products derived from this software without specific prior
16b0453382SBill Fenner  * written permission.
17b0453382SBill Fenner  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18b0453382SBill Fenner  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19b0453382SBill Fenner  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20b0453382SBill Fenner  */
21b0453382SBill Fenner 
223340d773SGleb Smirnoff /* \summary: IPv6 fragmentation header printer */
233340d773SGleb Smirnoff 
24ee67461eSJoseph Mingrone #include <config.h>
25b0453382SBill Fenner 
26ee67461eSJoseph Mingrone #include "netdissect-stdinc.h"
27b0453382SBill Fenner 
283340d773SGleb Smirnoff #include "netdissect.h"
295b0fe478SBruce M Simpson #include "extract.h"
30b0453382SBill Fenner 
310bff6a5aSEd Maste #include "ip6.h"
320bff6a5aSEd Maste 
33b0453382SBill Fenner int
frag6_print(netdissect_options * ndo,const u_char * bp,const u_char * bp2)34ee67461eSJoseph Mingrone frag6_print(netdissect_options *ndo, const u_char *bp, const u_char *bp2)
35b0453382SBill Fenner {
36ee67461eSJoseph Mingrone 	const struct ip6_frag *dp;
37ee67461eSJoseph Mingrone 	const struct ip6_hdr *ip6;
38b0453382SBill Fenner 
39ee67461eSJoseph Mingrone 	ndo->ndo_protocol = "frag6";
40a90e161bSBill Fenner 	dp = (const struct ip6_frag *)bp;
41a90e161bSBill Fenner 	ip6 = (const struct ip6_hdr *)bp2;
42b0453382SBill Fenner 
43*0a7e5f1fSJoseph Mingrone 	ND_PRINT("frag (");
44*0a7e5f1fSJoseph Mingrone 	if (ndo->ndo_vflag)
45*0a7e5f1fSJoseph Mingrone 		ND_PRINT("0x%08x:", GET_BE_U_4(dp->ip6f_ident));
46*0a7e5f1fSJoseph Mingrone 	ND_PRINT("%u|", GET_BE_U_2(dp->ip6f_offlg) & IP6F_OFF_MASK);
47*0a7e5f1fSJoseph Mingrone 	if ((bp - bp2) + sizeof(struct ip6_frag) >
48*0a7e5f1fSJoseph Mingrone 	    sizeof(struct ip6_hdr) + GET_BE_U_2(ip6->ip6_plen))
49*0a7e5f1fSJoseph Mingrone 		ND_PRINT("[length < 0] (invalid))");
50*0a7e5f1fSJoseph Mingrone 	else
51*0a7e5f1fSJoseph Mingrone 		ND_PRINT("%zu)",
52ee67461eSJoseph Mingrone 			 sizeof(struct ip6_hdr) + GET_BE_U_2(ip6->ip6_plen) -
53ee67461eSJoseph Mingrone 			 (bp - bp2) - sizeof(struct ip6_frag));
54b0453382SBill Fenner 
55b0453382SBill Fenner 	/* it is meaningless to decode non-first fragment */
56ee67461eSJoseph Mingrone 	if ((GET_BE_U_2(dp->ip6f_offlg) & IP6F_OFF_MASK) != 0)
575b0fe478SBruce M Simpson 		return -1;
58*0a7e5f1fSJoseph Mingrone 	else {
59ee67461eSJoseph Mingrone 		ND_PRINT(" ");
60b0453382SBill Fenner 		return sizeof(struct ip6_frag);
61b0453382SBill Fenner 	}
62b0453382SBill Fenner }
63