netfilter: replace list_head with single linked list

[cascardo/linux.git] / include / linux / netfilter.h

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index ad444f0..44e20da 100644 (file)
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -55,12 +55,34 @@ struct nf_hook_state {
        struct net_device *out;
        struct sock *sk;
        struct net *net;
-       struct list_head *hook_list;
+       struct nf_hook_entry __rcu *hook_entries;
        int (*okfn)(struct net *, struct sock *, struct sk_buff *);
 };
 
+typedef unsigned int nf_hookfn(void *priv,
+                              struct sk_buff *skb,
+                              const struct nf_hook_state *state);
+struct nf_hook_ops {
+       struct list_head        list;
+
+       /* User fills in from here down. */
+       nf_hookfn               *hook;
+       struct net_device       *dev;
+       void                    *priv;
+       u_int8_t                pf;
+       unsigned int            hooknum;
+       /* Hooks are ordered in ascending priority. */
+       int                     priority;
+};
+
+struct nf_hook_entry {
+       struct nf_hook_entry __rcu      *next;
+       struct nf_hook_ops              ops;
+       const struct nf_hook_ops        *orig_ops;
+};
+
 static inline void nf_hook_state_init(struct nf_hook_state *p,
-                                     struct list_head *hook_list,
+                                     struct nf_hook_entry *hook_entry,
                                      unsigned int hook,
                                      int thresh, u_int8_t pf,
                                      struct net_device *indev,
@@ -76,26 +98,11 @@ static inline void nf_hook_state_init(struct nf_hook_state *p,
        p->out = outdev;
        p->sk = sk;
        p->net = net;
-       p->hook_list = hook_list;
+       RCU_INIT_POINTER(p->hook_entries, hook_entry);
        p->okfn = okfn;
 }
 
-typedef unsigned int nf_hookfn(void *priv,
-                              struct sk_buff *skb,
-                              const struct nf_hook_state *state);
-
-struct nf_hook_ops {
-       struct list_head        list;
 
-       /* User fills in from here down. */
-       nf_hookfn               *hook;
-       struct net_device       *dev;
-       void                    *priv;
-       u_int8_t                pf;
-       unsigned int            hooknum;
-       /* Hooks are ordered in ascending priority. */
-       int                     priority;
-};
 
 struct nf_sockopt_ops {
        struct list_head list;
@@ -161,7 +168,8 @@ static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
                                 int (*okfn)(struct net *, struct sock *, struct sk_buff *),
                                 int thresh)
 {
-       struct list_head *hook_list;
+       struct nf_hook_entry *hook_head;
+       int ret = 1;
 
 #ifdef HAVE_JUMP_LABEL
        if (__builtin_constant_p(pf) &&
@@ -170,22 +178,19 @@ static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
                return 1;
 #endif
 
-       hook_list = &net->nf.hooks[pf][hook];
-
-       if (!list_empty(hook_list)) {
+       rcu_read_lock();
+       hook_head = rcu_dereference(net->nf.hooks[pf][hook]);
+       if (hook_head) {
                struct nf_hook_state state;
-               int ret;
 
-               /* We may already have this, but read-locks nest anyway */
-               rcu_read_lock();
-               nf_hook_state_init(&state, hook_list, hook, thresh,
+               nf_hook_state_init(&state, hook_head, hook, thresh,
                                   pf, indev, outdev, sk, net, okfn);
 
                ret = nf_hook_slow(skb, &state);
-               rcu_read_unlock();
-               return ret;
        }
-       return 1;
+       rcu_read_unlock();
+
+       return ret;
 }
 
 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,