include/linux/netfilter_ingress.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _NETFILTER_INGRESS_H_
   3 #define _NETFILTER_INGRESS_H_
   4
   5 #include <linux/netfilter.h>
   6 #include <linux/netdevice.h>
   7
   8 #ifdef CONFIG_NETFILTER_INGRESS
   9 static inline bool nf_hook_ingress_active(const struct sk_buff *skb)
  10 {
  11 #ifdef CONFIG_JUMP_LABEL
  12         if (!static_key_false(&nf_hooks_needed[NFPROTO_NETDEV][NF_NETDEV_INGRESS]))
  13                 return false;
  14 #endif
  15         return rcu_access_pointer(skb->dev->nf_hooks_ingress);
  16 }
  17
  18 /* caller must hold rcu_read_lock */
  19 static inline int nf_hook_ingress(struct sk_buff *skb)
  20 {
  21         struct nf_hook_entries *e = rcu_dereference(skb->dev->nf_hooks_ingress);
  22         struct nf_hook_state state;
  23         int ret;
  24
  25         /* Must recheck the ingress hook head, in the event it became NULL
  26          * after the check in nf_hook_ingress_active evaluated to true.
  27          */
  28         if (unlikely(!e))
  29                 return 0;
  30
  31         nf_hook_state_init(&state, NF_NETDEV_INGRESS,
  32                            NFPROTO_NETDEV, skb->dev, NULL, NULL,
  33                            dev_net(skb->dev), NULL);
  34         ret = nf_hook_slow(skb, &state, e, 0);
  35         if (ret == 0)
  36                 return -1;
  37
  38         return ret;
  39 }
  40
  41 static inline void nf_hook_ingress_init(struct net_device *dev)
  42 {
  43         RCU_INIT_POINTER(dev->nf_hooks_ingress, NULL);
  44 }
  45 #else /* CONFIG_NETFILTER_INGRESS */
  46 static inline int nf_hook_ingress_active(struct sk_buff *skb)
  47 {
  48         return 0;
  49 }
  50
  51 static inline int nf_hook_ingress(struct sk_buff *skb)
  52 {
  53         return 0;
  54 }
  55
  56 static inline void nf_hook_ingress_init(struct net_device *dev) {}
  57 #endif /* CONFIG_NETFILTER_INGRESS */
  58 #endif /* _NETFILTER_INGRESS_H_ */