diff options
| author | Florian Westphal <fw@strlen.de> | 2016-02-25 10:08:38 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-03-02 20:05:26 +0100 |
| commit | af4610c39589d839551da104f7da342d86f23ea0 (patch) | |
| tree | dd1aa462199737434bccc9b2f54cb8595d4e1407 /include/linux/netfilter.h | |
| parent | 5f6c253ebe93b02dece01c6f58447f16b29f6dd3 (diff) | |
netfilter: don't call hooks unless needed
With the previous patches in place, a netns nf_hook_list might be empty,
even if e.g. init_net performs filtering.
Thus change nf_hook_thresh to check the hook_list as well before
initializing hook_state and calling nf_hook_slow().
We still make use of static keys; if no netfilter modules are loaded
list is guaranteed to be empty.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include/linux/netfilter.h')
| -rw-r--r-- | include/linux/netfilter.h | 29 |
1 files changed, 11 insertions, 18 deletions
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index 0ad556726181..9230f9aee896 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -141,22 +141,6 @@ void nf_unregister_sockopt(struct nf_sockopt_ops *reg); #ifdef HAVE_JUMP_LABEL extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; - -static inline bool nf_hook_list_active(struct list_head *hook_list, - u_int8_t pf, unsigned int hook) -{ - if (__builtin_constant_p(pf) && - __builtin_constant_p(hook)) - return static_key_false(&nf_hooks_needed[pf][hook]); - - return !list_empty(hook_list); -} -#else -static inline bool nf_hook_list_active(struct list_head *hook_list, - u_int8_t pf, unsigned int hook) -{ - return !list_empty(hook_list); -} #endif int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state); @@ -177,9 +161,18 @@ 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 = &net->nf.hooks[pf][hook]; + struct list_head *hook_list; + +#ifdef HAVE_JUMP_LABEL + if (__builtin_constant_p(pf) && + __builtin_constant_p(hook) && + !static_key_false(&nf_hooks_needed[pf][hook])) + return 1; +#endif + + hook_list = &net->nf.hooks[pf][hook]; - if (nf_hook_list_active(hook_list, pf, hook)) { + if (!list_empty(hook_list)) { struct nf_hook_state state; nf_hook_state_init(&state, hook_list, hook, thresh, |