/*
* 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-ipcomp.c,v 1.8 2024/09/02 16:15:31 christos Exp $");
#endif

/* \summary: IP Payload Compression Protocol (IPComp) printer */

#include <config.h>

#include "netdissect-stdinc.h"

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

struct ipcomp {
       nd_uint8_t  comp_nxt;   /* Next Header */
       nd_uint8_t  comp_flags; /* Length of data, in 32bit */
       nd_uint16_t comp_cpi;   /* Compression parameter index */
};

void
ipcomp_print(netdissect_options *ndo, const u_char *bp)
{
       const struct ipcomp *ipcomp;
       uint16_t cpi;

       ndo->ndo_protocol = "ipcomp";
       ipcomp = (const struct ipcomp *)bp;
       cpi = GET_BE_U_2(ipcomp->comp_cpi);

       ND_PRINT("IPComp(cpi=0x%04x)", cpi);

       /*
        * XXX - based on the CPI, we could decompress the packet here.
        * Packet buffer management is a headache (if we decompress,
        * packet will become larger).
        *
        * We would decompress the packet and then call a routine that,
        * based on ipcomp->comp_nxt, dissects the decompressed data.
        *
        * Until we do that, however, we just return -1, so that
        * the loop that processes "protocol"/"next header" types
        * stops - there's nothing more it can do with a compressed
        * payload.
        */
}