/*      $NetBSD: npfext_rndblock.c,v 1.2 2018/09/29 14:41:37 rmind Exp $        */

/*-
 * Copyright (c) 2012 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__RCSID("$NetBSD: npfext_rndblock.c,v 1.2 2018/09/29 14:41:37 rmind Exp $");

#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <assert.h>
#include <errno.h>

#include <npf.h>

int             npfext_rndblock_init(void);
nl_ext_t *      npfext_rndblock_construct(const char *);
int             npfext_rndblock_param(nl_ext_t *, const char *, const char *);

int
npfext_rndblock_init(void)
{
        /* Nothing to initialise. */
        return 0;
}

nl_ext_t *
npfext_rndblock_construct(const char *name)
{
        assert(strcmp(name, "rndblock") == 0);
        return npf_ext_construct(name);
}

int
npfext_rndblock_param(nl_ext_t *ext, const char *param, const char *val)
{
        enum ptype { PARAM_U32 };
        static const struct param {
                const char *    name;
                enum ptype      type;
                signed long     min;
                signed long     max;
        } params[] = {
                { "mod",        PARAM_U32,      1,      LONG_MAX        },
                { "percentage", PARAM_U32,      1,      9999            },
        };

        if (val == NULL) {
                return EINVAL;
        }
        for (unsigned i = 0; i < __arraycount(params); i++) {
                const char *name = params[i].name;
                long ival;

                if (strcmp(name, param) != 0) {
                        continue;
                }

                /*
                 * Note: multiply by 100 and convert floating point to
                 * an integer, as 100% is based on 10000 in the kernel.
                 */
                ival = (i == 1) ? atof(val) * 100 : atol(val);
                if (ival < params[i].min || ival > params[i].max) {
                        return EINVAL;
                }
                assert(params[i].type == PARAM_U32);
                npf_ext_param_u32(ext, name, ival);
                return 0;
        }

        /* Invalid parameter, if not found. */
        return EINVAL;
}