/*
* Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994
*      The Regents of the University of California.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University nor the names of its contributors may be used to endorse
* or promote products derived from this software without specific prior
* written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: print-frag6.c,v 1.9 2024/09/02 16:15:31 christos Exp $");
#endif

/* \summary: IPv6 fragmentation header printer */

#include <config.h>

#include "netdissect-stdinc.h"

#include "netdissect.h"
#include "extract.h"

#include "ip6.h"

int
frag6_print(netdissect_options *ndo, const u_char *bp, const u_char *bp2)
{
       const struct ip6_frag *dp;
       const struct ip6_hdr *ip6;

       ndo->ndo_protocol = "frag6";
       dp = (const struct ip6_frag *)bp;
       ip6 = (const struct ip6_hdr *)bp2;

       ND_PRINT("frag (");
       if (ndo->ndo_vflag)
               ND_PRINT("0x%08x:", GET_BE_U_4(dp->ip6f_ident));
       ND_PRINT("%u|", GET_BE_U_2(dp->ip6f_offlg) & IP6F_OFF_MASK);
       if ((bp - bp2) + sizeof(struct ip6_frag) >
           sizeof(struct ip6_hdr) + GET_BE_U_2(ip6->ip6_plen))
               ND_PRINT("[length < 0] (invalid))");
       else
               ND_PRINT("%zu)",
                        sizeof(struct ip6_hdr) + GET_BE_U_2(ip6->ip6_plen) -
                        (bp - bp2) - sizeof(struct ip6_frag));

       /* it is meaningless to decode non-first fragment */
       if ((GET_BE_U_2(dp->ip6f_offlg) & IP6F_OFF_MASK) != 0)
               return -1;
       else {
               ND_PRINT(" ");
               return sizeof(struct ip6_frag);
       }
}