/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
#include <sys/param.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/modctl.h>
#include <sys/neti.h>
#include <sys/hook.h>
#include <sys/zone.h>

/*
 * This file provides kernel hook framework.
 */

static struct modldrv modlmisc = {
	&mod_miscops,				/* drv_modops */
	"sample",			/* drv_linkinfo */
};

static struct modlinkage modlinkage = {
	MODREV_1,				/* ml_rev */
	&modlmisc,				/* ml_linkage */
	NULL
};

static void sample_init(void);
static void sample_fini(void);
static int sample_func(hook_event_token_t token, hook_data_t info, void *arg);

static net_callback_t *cb = NULL;
static net_data_t ipv4 = 0;
static hook_t *hk = NULL;

/*
 * Module entry points.
 */
int
_init(void)
{
	int error;

	sample_init();
	error = mod_install(&modlinkage);
	if (error != 0)
		sample_fini();

	return (error);
}


int
_fini(void)
{
	int error;

	error = mod_remove(&modlinkage);
	if (error == 0)
		sample_fini();

	return (error); }

int
_info(struct modinfo *modinfop)
{
	return (mod_info(&modlinkage, modinfop));
}

/*
 * Function:	sample_init
 * Returns:	None
 * Parameters:	None
 *
 * Initialize hooks
 */
static void
sample_init(void)
{
	ipv4 = net_protocol_lookup(GLOBAL_NETID, NHF_INET);

	hk = hook_alloc(HOOK_VERSION);
	hk->h_func = sample_func;
	hk->h_name = "sample";
	hk->h_flags = 0;
	hk->h_hint = HH_BEFORE;
	hk->h_hintvalue = (uintptr_t)"ipfilter_hook_in";
	hk->h_arg = NULL;

	if (net_hook_register(ipv4, NH_PHYSICAL_IN, hk) == -1)
		printf("net_hook_register failed\n");
	else
		printf("net_hook_register succeeded\n");
}


static void
sample_fini(void)
{
	if (ipv4 && (hk != NULL)) {
		net_hook_unregister(ipv4, NH_PHYSICAL_IN, hk);
		printf("net_hook_unregister called\n");
	}

	if (hk != NULL) {
		hook_free(hk);
		hk = NULL;
	}

	if (ipv4) {
		net_protocol_release(ipv4);
		ipv4 = 0;
	}
}


static int
sample_func(hook_event_token_t token, hook_data_t info, void *arg)
{
	printf("token=%p info=%p arg=%p\n", token, info, arg);
	return (0);
}