/*      NetBSD: print-ah.c,v 1.4 1996/05/20 00:41:16 fvdl Exp   */

/*
* Copyright (c) 1988, 1989, 1990, 1991, 1992, 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-ah.c,v 1.9 2024/09/02 16:15:30 christos Exp $");
#endif

/* \summary: IPSEC Authentication Header printer */

#include <config.h>

#include "netdissect-stdinc.h"

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

#include "ah.h"

int
ah_print(netdissect_options *ndo, const u_char *bp)
{
       const struct ah *ah;
       uint8_t ah_len;
       u_int ah_hdr_len;
       uint16_t reserved;
       const u_char *p;

       ndo->ndo_protocol = "ah";
       ah = (const struct ah *)bp;

       nd_print_protocol_caps(ndo);
/*
* RFC4302
*
* 2.2.  Payload Length
*
*    This 8-bit field specifies the length of AH in 32-bit words (4-byte
*    units), minus "2".
*/
       ah_len = GET_U_1(ah->ah_len);
       ah_hdr_len = (ah_len + 2) * 4;

       ND_PRINT("(");
       if (ndo->ndo_vflag)
               ND_PRINT("length=%u(%u-bytes),", ah_len, ah_hdr_len);
       reserved = GET_BE_U_2(ah->ah_reserved);
       if (reserved)
               ND_PRINT("reserved=0x%x[MustBeZero],", reserved);
       ND_PRINT("spi=0x%08x,", GET_BE_U_4(ah->ah_spi));
       ND_PRINT("seq=0x%x,", GET_BE_U_4(ah->ah_seq));
       ND_PRINT("icv=0x");
       for (p = (const u_char *)(ah + 1); p < bp + ah_hdr_len; p++)
               ND_PRINT("%02x", GET_U_1(p));
       ND_PRINT("): ");

       return ah_hdr_len;
}