From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: [PATCH -next 8/8] netfilter: don't call nf_hook_state_init/_hook_slow unless needed Date: Fri, 2 Oct 2015 13:49:17 +0200 Message-ID: <1443786557-21315-9-git-send-email-fw@strlen.de> References: <1443786557-21315-1-git-send-email-fw@strlen.de> Cc: ebiederm@xmission.com, Florian Westphal To: Return-path: Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:50315 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752567AbbJBLtb (ORCPT ); Fri, 2 Oct 2015 07:49:31 -0400 In-Reply-To: <1443786557-21315-1-git-send-email-fw@strlen.de> Sender: netfilter-devel-owner@vger.kernel.org List-ID: With the previous patches in place, a netns nf_hook_list might be empty, even if e.g. init_net performs filtering/conntrack. 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 hooks are loaded we can elide further testing since list is guaranteed to be empty. Signed-off-by: Florian Westphal --- include/linux/netfilter.h | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-) diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index 165ab2d..3f2d9b8 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -142,22 +142,6 @@ 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); @@ -178,9 +162,18 @@ 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, -- 2.0.5