nf_tables_netdev.c
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/*
* Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <net/netfilter/nf_tables.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <net/netfilter/nf_tables_ipv4.h>
#include <net/netfilter/nf_tables_ipv6.h>
static unsigned int
nft_do_chain_netdev(void *priv, struct sk_buff *skb,
const struct nf_hook_state *state)
{
struct nft_pktinfo pkt;
switch (skb->protocol) {
case htons(ETH_P_IP):
nft_set_pktinfo_ipv4_validate(&pkt, skb, state);
break;
case htons(ETH_P_IPV6):
nft_set_pktinfo_ipv6_validate(&pkt, skb, state);
break;
default:
nft_set_pktinfo_unspec(&pkt, skb, state);
break;
}
return nft_do_chain(&pkt, priv);
}
static struct nft_af_info nft_af_netdev __read_mostly = {
.family = NFPROTO_NETDEV,
.nhooks = NF_NETDEV_NUMHOOKS,
.owner = THIS_MODULE,
.flags = NFT_AF_NEEDS_DEV,
.nops = 1,
.hooks = {
[NF_NETDEV_INGRESS] = nft_do_chain_netdev,
},
};
static int nf_tables_netdev_init_net(struct net *net)
{
net->nft.netdev = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL);
if (net->nft.netdev == NULL)
return -ENOMEM;
memcpy(net->nft.netdev, &nft_af_netdev, sizeof(nft_af_netdev));
if (nft_register_afinfo(net, net->nft.netdev) < 0)
goto err;
return 0;
err:
kfree(net->nft.netdev);
return -ENOMEM;
}
static void nf_tables_netdev_exit_net(struct net *net)
{
nft_unregister_afinfo(net, net->nft.netdev);
kfree(net->nft.netdev);
}
static struct pernet_operations nf_tables_netdev_net_ops = {
.init = nf_tables_netdev_init_net,
.exit = nf_tables_netdev_exit_net,
};
static const struct nf_chain_type nft_filter_chain_netdev = {
.name = "filter",
.type = NFT_CHAIN_T_DEFAULT,
.family = NFPROTO_NETDEV,
.owner = THIS_MODULE,
.hook_mask = (1 << NF_NETDEV_INGRESS),
};
static void nft_netdev_event(unsigned long event, struct net_device *dev,
struct nft_ctx *ctx)
{
struct nft_base_chain *basechain = nft_base_chain(ctx->chain);
switch (event) {
case NETDEV_UNREGISTER:
if (strcmp(basechain->dev_name, dev->name) != 0)
return;
__nft_release_basechain(ctx);
break;
case NETDEV_CHANGENAME:
if (dev->ifindex != basechain->ops[0].dev->ifindex)
return;
strncpy(basechain->dev_name, dev->name, IFNAMSIZ);
break;
}
}
static int nf_tables_netdev_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct nft_af_info *afi;
struct nft_table *table;
struct nft_chain *chain, *nr;
struct nft_ctx ctx = {
.net = dev_net(dev),
};
if (event != NETDEV_UNREGISTER &&
event != NETDEV_CHANGENAME)
return NOTIFY_DONE;
nfnl_lock(NFNL_SUBSYS_NFTABLES);
list_for_each_entry(afi, &dev_net(dev)->nft.af_info, list) {
ctx.afi = afi;
if (afi->family != NFPROTO_NETDEV)
continue;
list_for_each_entry(table, &afi->tables, list) {
ctx.table = table;
list_for_each_entry_safe(chain, nr, &table->chains, list) {
if (!(chain->flags & NFT_BASE_CHAIN))
continue;
ctx.chain = chain;
nft_netdev_event(event, dev, &ctx);
}
}
}
nfnl_unlock(NFNL_SUBSYS_NFTABLES);
return NOTIFY_DONE;
}
static struct notifier_block nf_tables_netdev_notifier = {
.notifier_call = nf_tables_netdev_event,
};
static int __init nf_tables_netdev_init(void)
{
int ret;
ret = nft_register_chain_type(&nft_filter_chain_netdev);
if (ret)
return ret;
ret = register_pernet_subsys(&nf_tables_netdev_net_ops);
if (ret)
goto err1;
ret = register_netdevice_notifier(&nf_tables_netdev_notifier);
if (ret)
goto err2;
return 0;
err2:
unregister_pernet_subsys(&nf_tables_netdev_net_ops);
err1:
nft_unregister_chain_type(&nft_filter_chain_netdev);
return ret;
}
static void __exit nf_tables_netdev_exit(void)
{
unregister_netdevice_notifier(&nf_tables_netdev_notifier);
unregister_pernet_subsys(&nf_tables_netdev_net_ops);
nft_unregister_chain_type(&nft_filter_chain_netdev);
}
module_init(nf_tables_netdev_init);
module_exit(nf_tables_netdev_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
MODULE_ALIAS_NFT_FAMILY(5); /* NFPROTO_NETDEV */