// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
 */

#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>

#include <linux/netfilter/xt_devgroup.h>
#include <linux/netfilter/x_tables.h>

MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Xtables: Device group match");
MODULE_ALIAS("ipt_devgroup");
MODULE_ALIAS("ip6t_devgroup");

static bool devgroup_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
        const struct xt_devgroup_info *info = par->matchinfo;

        if (info->flags & XT_DEVGROUP_MATCH_SRC &&
            (((info->src_group ^ xt_in(par)->group) & info->src_mask ? 1 : 0) ^
             ((info->flags & XT_DEVGROUP_INVERT_SRC) ? 1 : 0)))
                return false;

        if (info->flags & XT_DEVGROUP_MATCH_DST &&
            (((info->dst_group ^ xt_out(par)->group) & info->dst_mask ? 1 : 0) ^
             ((info->flags & XT_DEVGROUP_INVERT_DST) ? 1 : 0)))
                return false;

        return true;
}

static int devgroup_mt_checkentry(const struct xt_mtchk_param *par)
{
        const struct xt_devgroup_info *info = par->matchinfo;

        if (info->flags & ~(XT_DEVGROUP_MATCH_SRC | XT_DEVGROUP_INVERT_SRC |
                            XT_DEVGROUP_MATCH_DST | XT_DEVGROUP_INVERT_DST))
                return -EINVAL;

        if (info->flags & XT_DEVGROUP_MATCH_SRC &&
            par->hook_mask & ~((1 << NF_INET_PRE_ROUTING) |
                               (1 << NF_INET_LOCAL_IN) |
                               (1 << NF_INET_FORWARD)))
                return -EINVAL;

        if (info->flags & XT_DEVGROUP_MATCH_DST &&
            par->hook_mask & ~((1 << NF_INET_FORWARD) |
                               (1 << NF_INET_LOCAL_OUT) |
                               (1 << NF_INET_POST_ROUTING)))
                return -EINVAL;

        return 0;
}

static struct xt_match devgroup_mt_reg __read_mostly = {
        .name           = "devgroup",
        .match          = devgroup_mt,
        .checkentry     = devgroup_mt_checkentry,
        .matchsize      = sizeof(struct xt_devgroup_info),
        .family         = NFPROTO_UNSPEC,
        .me             = THIS_MODULE
};

static int __init devgroup_mt_init(void)
{
        return xt_register_match(&devgroup_mt_reg);
}

static void __exit devgroup_mt_exit(void)
{
        xt_unregister_match(&devgroup_mt_reg);
}

module_init(devgroup_mt_init);
module_exit(devgroup_mt_exit);