xref: /openbsd/usr.sbin/tcpdump/print-frag6.c (revision 76d0caae)
1 /*	$OpenBSD: print-frag6.c,v 1.10 2020/01/24 22:46:36 procter Exp $	*/
2 
3 /*
4  * Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that: (1) source code distributions
9  * retain the above copyright notice and this paragraph in its entirety, (2)
10  * distributions including binary code include the above copyright notice and
11  * this paragraph in its entirety in the documentation or other materials
12  * provided with the distribution, and (3) all advertising materials mentioning
13  * features or use of this software display the following acknowledgement:
14  * ``This product includes software developed by the University of California,
15  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
16  * the University nor the names of its contributors may be used to endorse
17  * or promote products derived from this software without specific prior
18  * written permission.
19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
20  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
21  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22  */
23 
24 #include <sys/time.h>
25 #include <sys/types.h>
26 #include <sys/socket.h>
27 
28 #include <net/if.h>
29 
30 #include <netinet/in.h>
31 #include <netinet/if_ether.h>
32 #include <netinet/ip.h>
33 #include <netinet/ip_icmp.h>
34 #include <netinet/ip_var.h>
35 #include <netinet/udp.h>
36 #include <netinet/udp_var.h>
37 #include <netinet/tcp.h>
38 
39 #include <stdio.h>
40 
41 #include <netinet/ip6.h>
42 
43 #include "interface.h"
44 #include "addrtoname.h"
45 
46 int
47 frag6_print(const u_char *bp, const u_char *bp2)
48 {
49 	const struct ip6_frag *dp;
50 	const struct ip6_hdr *ip6;
51 	const u_char *ep;
52 
53 #if 0
54 #define TCHECK(var) if ((u_char *)&(var) >= ep - sizeof(var)) goto trunc
55 #endif
56 
57 	dp = (struct ip6_frag *)bp;
58 	ip6 = (struct ip6_hdr *)bp2;
59 
60 	/* 'ep' points to the end of avaible data. */
61 	ep = snapend;
62 
63 	TCHECK(dp->ip6f_ident);
64 
65 	printf("frag (0x%08x:%ld@%d%s)",
66 	    ntohl(dp->ip6f_ident),
67 	    sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen) -
68 		(long)(bp - bp2) - sizeof(struct ip6_frag),
69 	    ntohs(dp->ip6f_offlg & IP6F_OFF_MASK),
70 	    (dp->ip6f_offlg & IP6F_MORE_FRAG) ? "+" : "");
71 
72 	/* it is meaningless to decode non-first fragment */
73 	if (ntohs(dp->ip6f_offlg & IP6F_OFF_MASK) != 0)
74 		return 65535;
75 	else
76 	{
77 		printf(" ");
78 		return sizeof(struct ip6_frag);
79 	}
80 trunc:
81 	printf("[|frag]");
82 	return 65535;
83 #undef TCHECK
84 }
85