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-frag6.c,v 1.9 2024/09/02 16:15:31 christos Exp $");
25 #endif
26
27 /* \summary: IPv6 fragmentation header printer */
28
29 #include <config.h>
30
31 #include "netdissect-stdinc.h"
32
33 #include "netdissect.h"
34 #include "extract.h"
35
36 #include "ip6.h"
37
38 int
frag6_print(netdissect_options * ndo,const u_char * bp,const u_char * bp2)39 frag6_print(netdissect_options *ndo, const u_char *bp, const u_char *bp2)
40 {
41 const struct ip6_frag *dp;
42 const struct ip6_hdr *ip6;
43
44 ndo->ndo_protocol = "frag6";
45 dp = (const struct ip6_frag *)bp;
46 ip6 = (const struct ip6_hdr *)bp2;
47
48 ND_PRINT("frag (");
49 if (ndo->ndo_vflag)
50 ND_PRINT("0x%08x:", GET_BE_U_4(dp->ip6f_ident));
51 ND_PRINT("%u|", GET_BE_U_2(dp->ip6f_offlg) & IP6F_OFF_MASK);
52 if ((bp - bp2) + sizeof(struct ip6_frag) >
53 sizeof(struct ip6_hdr) + GET_BE_U_2(ip6->ip6_plen))
54 ND_PRINT("[length < 0] (invalid))");
55 else
56 ND_PRINT("%zu)",
57 sizeof(struct ip6_hdr) + GET_BE_U_2(ip6->ip6_plen) -
58 (bp - bp2) - sizeof(struct ip6_frag));
59
60 /* it is meaningless to decode non-first fragment */
61 if ((GET_BE_U_2(dp->ip6f_offlg) & IP6F_OFF_MASK) != 0)
62 return -1;
63 else {
64 ND_PRINT(" ");
65 return sizeof(struct ip6_frag);
66 }
67 }
68