blob: a8e2425e43b0d755cc5cfc5a14c0e42785dc3849 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_offload.h>
#include <net/netfilter/nf_dup_netdev.h>
#define NF_RECURSION_LIMIT 2
static DEFINE_PER_CPU(u8, nf_dup_skb_recursion);
static void nf_do_netdev_egress(struct sk_buff *skb, struct net_device *dev,
enum nf_dev_hooks hook)
{
if (__this_cpu_read(nf_dup_skb_recursion) > NF_RECURSION_LIMIT)
goto err;
if (hook == NF_NETDEV_INGRESS && skb_mac_header_was_set(skb)) {
if (skb_cow_head(skb, skb->mac_len))
goto err;
skb_push(skb, skb->mac_len);
}
skb->dev = dev;
skb_clear_tstamp(skb);
__this_cpu_inc(nf_dup_skb_recursion);
dev_queue_xmit(skb);
__this_cpu_dec(nf_dup_skb_recursion);
return;
err:
kfree_skb(skb);
}
void nf_fwd_netdev_egress(const struct nft_pktinfo *pkt, int oif)
{
struct net_device *dev;
dev = dev_get_by_index_rcu(nft_net(pkt), oif);
if (!dev) {
kfree_skb(pkt->skb);
return;
}
nf_do_netdev_egress(pkt->skb, dev, nft_hook(pkt));
}
EXPORT_SYMBOL_GPL(nf_fwd_netdev_egress);
void nf_dup_netdev_egress(const struct nft_pktinfo *pkt, int oif)
{
struct net_device *dev;
struct sk_buff *skb;
dev = dev_get_by_index_rcu(nft_net(pkt), oif);
if (dev == NULL)
return;
skb = skb_clone(pkt->skb, GFP_ATOMIC);
if (skb)
nf_do_netdev_egress(skb, dev, nft_hook(pkt));
}
EXPORT_SYMBOL_GPL(nf_dup_netdev_egress);
int nft_fwd_dup_netdev_offload(struct nft_offload_ctx *ctx,
struct nft_flow_rule *flow,
enum flow_action_id id, int oif)
{
struct flow_action_entry *entry;
struct net_device *dev;
/* nft_flow_rule_destroy() releases the reference on this device. */
dev = dev_get_by_index(ctx->net, oif);
if (!dev)
return -EOPNOTSUPP;
entry = &flow->rule->action.entries[ctx->num_actions++];
entry->id = id;
entry->dev = dev;
return 0;
}
EXPORT_SYMBOL_GPL(nft_fwd_dup_netdev_offload);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
MODULE_DESCRIPTION("Netfilter packet duplication support");