mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-27 12:57:53 +00:00
d645552e9b
Otherwise packets in egress chains seem like they are being received by
the interface, not sent out via it.
Fixes: 42df6e1d22
("netfilter: Introduce egress hook")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
150 lines
4 KiB
C
150 lines
4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _NETFILTER_NETDEV_H_
|
|
#define _NETFILTER_NETDEV_H_
|
|
|
|
#include <linux/netfilter.h>
|
|
#include <linux/netdevice.h>
|
|
|
|
#ifdef CONFIG_NETFILTER_INGRESS
|
|
static inline bool nf_hook_ingress_active(const struct sk_buff *skb)
|
|
{
|
|
#ifdef CONFIG_JUMP_LABEL
|
|
if (!static_key_false(&nf_hooks_needed[NFPROTO_NETDEV][NF_NETDEV_INGRESS]))
|
|
return false;
|
|
#endif
|
|
return rcu_access_pointer(skb->dev->nf_hooks_ingress);
|
|
}
|
|
|
|
/* caller must hold rcu_read_lock */
|
|
static inline int nf_hook_ingress(struct sk_buff *skb)
|
|
{
|
|
struct nf_hook_entries *e = rcu_dereference(skb->dev->nf_hooks_ingress);
|
|
struct nf_hook_state state;
|
|
int ret;
|
|
|
|
/* Must recheck the ingress hook head, in the event it became NULL
|
|
* after the check in nf_hook_ingress_active evaluated to true.
|
|
*/
|
|
if (unlikely(!e))
|
|
return 0;
|
|
|
|
nf_hook_state_init(&state, NF_NETDEV_INGRESS,
|
|
NFPROTO_NETDEV, skb->dev, NULL, NULL,
|
|
dev_net(skb->dev), NULL);
|
|
ret = nf_hook_slow(skb, &state, e, 0);
|
|
if (ret == 0)
|
|
return -1;
|
|
|
|
return ret;
|
|
}
|
|
|
|
#else /* CONFIG_NETFILTER_INGRESS */
|
|
static inline int nf_hook_ingress_active(struct sk_buff *skb)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int nf_hook_ingress(struct sk_buff *skb)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_NETFILTER_INGRESS */
|
|
|
|
#ifdef CONFIG_NETFILTER_EGRESS
|
|
static inline bool nf_hook_egress_active(void)
|
|
{
|
|
#ifdef CONFIG_JUMP_LABEL
|
|
if (!static_key_false(&nf_hooks_needed[NFPROTO_NETDEV][NF_NETDEV_EGRESS]))
|
|
return false;
|
|
#endif
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* nf_hook_egress - classify packets before transmission
|
|
* @skb: packet to be classified
|
|
* @rc: result code which shall be returned by __dev_queue_xmit() on failure
|
|
* @dev: netdev whose egress hooks shall be applied to @skb
|
|
*
|
|
* Returns @skb on success or %NULL if the packet was consumed or filtered.
|
|
* Caller must hold rcu_read_lock.
|
|
*
|
|
* On ingress, packets are classified first by tc, then by netfilter.
|
|
* On egress, the order is reversed for symmetry. Conceptually, tc and
|
|
* netfilter can be thought of as layers, with netfilter layered above tc:
|
|
* When tc redirects a packet to another interface, netfilter is not applied
|
|
* because the packet is on the tc layer.
|
|
*
|
|
* The nf_skip_egress flag controls whether netfilter is applied on egress.
|
|
* It is updated by __netif_receive_skb_core() and __dev_queue_xmit() when the
|
|
* packet passes through tc and netfilter. Because __dev_queue_xmit() may be
|
|
* called recursively by tunnel drivers such as vxlan, the flag is reverted to
|
|
* false after sch_handle_egress(). This ensures that netfilter is applied
|
|
* both on the overlay and underlying network.
|
|
*/
|
|
static inline struct sk_buff *nf_hook_egress(struct sk_buff *skb, int *rc,
|
|
struct net_device *dev)
|
|
{
|
|
struct nf_hook_entries *e;
|
|
struct nf_hook_state state;
|
|
int ret;
|
|
|
|
#ifdef CONFIG_NETFILTER_SKIP_EGRESS
|
|
if (skb->nf_skip_egress)
|
|
return skb;
|
|
#endif
|
|
|
|
e = rcu_dereference_check(dev->nf_hooks_egress, rcu_read_lock_bh_held());
|
|
if (!e)
|
|
return skb;
|
|
|
|
nf_hook_state_init(&state, NF_NETDEV_EGRESS,
|
|
NFPROTO_NETDEV, NULL, dev, NULL,
|
|
dev_net(dev), NULL);
|
|
|
|
/* nf assumes rcu_read_lock, not just read_lock_bh */
|
|
rcu_read_lock();
|
|
ret = nf_hook_slow(skb, &state, e, 0);
|
|
rcu_read_unlock();
|
|
|
|
if (ret == 1) {
|
|
return skb;
|
|
} else if (ret < 0) {
|
|
*rc = NET_XMIT_DROP;
|
|
return NULL;
|
|
} else { /* ret == 0 */
|
|
*rc = NET_XMIT_SUCCESS;
|
|
return NULL;
|
|
}
|
|
}
|
|
#else /* CONFIG_NETFILTER_EGRESS */
|
|
static inline bool nf_hook_egress_active(void)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline struct sk_buff *nf_hook_egress(struct sk_buff *skb, int *rc,
|
|
struct net_device *dev)
|
|
{
|
|
return skb;
|
|
}
|
|
#endif /* CONFIG_NETFILTER_EGRESS */
|
|
|
|
static inline void nf_skip_egress(struct sk_buff *skb, bool skip)
|
|
{
|
|
#ifdef CONFIG_NETFILTER_SKIP_EGRESS
|
|
skb->nf_skip_egress = skip;
|
|
#endif
|
|
}
|
|
|
|
static inline void nf_hook_netdev_init(struct net_device *dev)
|
|
{
|
|
#ifdef CONFIG_NETFILTER_INGRESS
|
|
RCU_INIT_POINTER(dev->nf_hooks_ingress, NULL);
|
|
#endif
|
|
#ifdef CONFIG_NETFILTER_EGRESS
|
|
RCU_INIT_POINTER(dev->nf_hooks_egress, NULL);
|
|
#endif
|
|
}
|
|
|
|
#endif /* _NETFILTER_NETDEV_H_ */
|