linux/net/ipv4/netfilter/ipt_rpfilter.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2011 Florian Westphal <[email protected]>
 *
 * based on fib_frontend.c; Author: Alexey Kuznetsov, <[email protected]>
 */
#define pr_fmt(fmt) …
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/ip.h>
#include <net/ip.h>
#include <net/ip_fib.h>
#include <net/route.h>

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

MODULE_LICENSE(…) …;
MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;

/* don't try to find route from mcast/bcast/zeronet */
static __be32 rpfilter_get_saddr(__be32 addr)
{ … }

static bool rpfilter_lookup_reverse(struct net *net, struct flowi4 *fl4,
				const struct net_device *dev, u8 flags)
{ … }

static bool
rpfilter_is_loopback(const struct sk_buff *skb, const struct net_device *in)
{ … }

static bool rpfilter_mt(const struct sk_buff *skb, struct xt_action_param *par)
{ … }

static int rpfilter_check(const struct xt_mtchk_param *par)
{ … }

static struct xt_match rpfilter_mt_reg __read_mostly = …;

static int __init rpfilter_mt_init(void)
{ … }

static void __exit rpfilter_mt_exit(void)
{ … }

module_init(…) …;
module_exit(rpfilter_mt_exit);