redonkable/alistair23-linux
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netfilter: Generalize ingress hook

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Prepare for addition of a netfilter egress hook by generalizing the
ingress hook introduced by commit e687ad60af ("netfilter: add
netfilter ingress hook after handle_ing() under unique static key").

In particular, rename and refactor the ingress hook's static inlines
such that they can be reused for an egress hook.

No functional change intended.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Lukas Wunner 2020-03-11 12:59:02 +01:00 committed by Pablo Neira Ayuso
parent b030f194ae
commit 5418d3881e
2 changed files with 32 additions and 15 deletions
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45
include/linux/netfilter_netdev.h
View file

@ -1,34 +1,37 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _NETFILTER_INGRESS_H_
#define _NETFILTER_INGRESS_H_
#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_NETFILTER
static __always_inline bool nf_hook_netdev_active(enum nf_dev_hooks hooknum,
struct nf_hook_entries __rcu *hooks)
{
#ifdef CONFIG_JUMP_LABEL
if (!static_key_false(&nf_hooks_needed[NFPROTO_NETDEV][NF_NETDEV_INGRESS]))
if (!static_key_false(&nf_hooks_needed[NFPROTO_NETDEV][hooknum]))
return false;
#endif
return rcu_access_pointer(skb->dev->nf_hooks_ingress);
return rcu_access_pointer(hooks);
}
/* caller must hold rcu_read_lock */
static inline int nf_hook_ingress(struct sk_buff *skb)
static __always_inline int nf_hook_netdev(struct sk_buff *skb,
enum nf_dev_hooks hooknum,
struct nf_hook_entries __rcu *hooks)
{
struct nf_hook_entries *e = rcu_dereference(skb->dev->nf_hooks_ingress);
struct nf_hook_entries *e = rcu_dereference(hooks);
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.
/* Must recheck the hook head, in the event it became NULL
* after the check in nf_hook_netdev_active evaluated to true.
*/
if (unlikely(!e))
return 0;
nf_hook_state_init(&state, NF_NETDEV_INGRESS,
nf_hook_state_init(&state, hooknum,
NFPROTO_NETDEV, skb->dev, NULL, NULL,
dev_net(skb->dev), NULL);
ret = nf_hook_slow(skb, &state, e, 0);
@ -37,10 +40,26 @@ static inline int nf_hook_ingress(struct sk_buff *skb)
return ret;
}
#endif /* CONFIG_NETFILTER */
static inline void nf_hook_ingress_init(struct net_device *dev)
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_INGRESS
static inline bool nf_hook_ingress_active(const struct sk_buff *skb)
{
return nf_hook_netdev_active(NF_NETDEV_INGRESS,
skb->dev->nf_hooks_ingress);
}
static inline int nf_hook_ingress(struct sk_buff *skb)
{
return nf_hook_netdev(skb, NF_NETDEV_INGRESS,
skb->dev->nf_hooks_ingress);
}
#else /* CONFIG_NETFILTER_INGRESS */
static inline int nf_hook_ingress_active(struct sk_buff *skb)
@ -52,7 +71,5 @@ static inline int nf_hook_ingress(struct sk_buff *skb)
{
return 0;
}
static inline void nf_hook_ingress_init(struct net_device *dev) {}
#endif /* CONFIG_NETFILTER_INGRESS */
#endif /* _NETFILTER_INGRESS_H_ */

2
net/core/dev.c
View file

@ -9846,7 +9846,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
if (!dev->ethtool_ops)
dev->ethtool_ops = &default_ethtool_ops;
nf_hook_ingress_init(dev);
nf_hook_netdev_init(dev);
return dev;