From 2a6decfd8a5fae0422c98a22aa6bc30224b8a3ec Mon Sep 17 00:00:00 2001 From: Michael Wang Date: Wed, 22 Aug 2012 19:59:57 +0000 Subject: [PATCH] netfilter: pass 'nf_hook_ops' instead of 'list_head' to nf_iterate() Since 'list_for_each_continue_rcu' has already been replaced by 'list_for_each_entry_continue_rcu', pass 'list_head' to nf_iterate() as a parameter can not benefit us any more. This patch will replace 'list_head' with 'nf_hook_ops' as the parameter of nf_iterate() to save code. Signed-off-by: Michael Wang Signed-off-by: Pablo Neira Ayuso --- net/netfilter/core.c | 24 ++++++++++-------------- net/netfilter/nf_internals.h | 2 +- net/netfilter/nf_queue.c | 6 +++--- 3 files changed, 14 insertions(+), 18 deletions(-) diff --git a/net/netfilter/core.c b/net/netfilter/core.c index e61b3ac..0b119d9 100644 --- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -126,42 +126,38 @@ unsigned int nf_iterate(struct list_head *head, unsigned int hook, const struct net_device *indev, const struct net_device *outdev, - struct list_head **i, + struct nf_hook_ops **elemp, int (*okfn)(struct sk_buff *), int hook_thresh) { unsigned int verdict; - struct nf_hook_ops *elem = list_entry_rcu(*i, struct nf_hook_ops, list); /* * The caller must not block between calls to this * function because of risk of continuing from deleted element. */ - list_for_each_entry_continue_rcu(elem, head, list) { - if (hook_thresh > elem->priority) + list_for_each_entry_continue_rcu((*elemp), head, list) { + if (hook_thresh > (*elemp)->priority) continue; /* Optimization: we don't need to hold module reference here, since function can't sleep. --RR */ repeat: - verdict = elem->hook(hook, skb, indev, outdev, okfn); + verdict = (*elemp)->hook(hook, skb, indev, outdev, okfn); if (verdict != NF_ACCEPT) { #ifdef CONFIG_NETFILTER_DEBUG if (unlikely((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT)) { NFDEBUG("Evil return from %p(%u).\n", - elem->hook, hook); + (*elemp)->hook, hook); continue; } #endif - if (verdict != NF_REPEAT) { - *i = &elem->list; + if (verdict != NF_REPEAT) return verdict; - } goto repeat; } } - *i = &elem->list; return NF_ACCEPT; } @@ -174,14 +170,14 @@ int nf_hook_slow(u_int8_t pf, unsigned int hook, struct sk_buff *skb, int (*okfn)(struct sk_buff *), int hook_thresh) { - struct list_head *elem; + struct nf_hook_ops *elem; unsigned int verdict; int ret = 0; /* We may already have this, but read-locks nest anyway */ rcu_read_lock(); - elem = &nf_hooks[pf][hook]; + elem = list_entry_rcu(&nf_hooks[pf][hook], struct nf_hook_ops, list); next_hook: verdict = nf_iterate(&nf_hooks[pf][hook], skb, hook, indev, outdev, &elem, okfn, hook_thresh); @@ -193,8 +189,8 @@ next_hook: if (ret == 0) ret = -EPERM; } else if ((verdict & NF_VERDICT_MASK) == NF_QUEUE) { - int err = nf_queue(skb, elem, pf, hook, indev, outdev, okfn, - verdict >> NF_VERDICT_QBITS); + int err = nf_queue(skb, &elem->list, pf, hook, indev, outdev, + okfn, verdict >> NF_VERDICT_QBITS); if (err < 0) { if (err == -ECANCELED) goto next_hook; diff --git a/net/netfilter/nf_internals.h b/net/netfilter/nf_internals.h index 770f764..2886231 100644 --- a/net/netfilter/nf_internals.h +++ b/net/netfilter/nf_internals.h @@ -18,7 +18,7 @@ extern unsigned int nf_iterate(struct list_head *head, unsigned int hook, const struct net_device *indev, const struct net_device *outdev, - struct list_head **i, + struct nf_hook_ops **elemp, int (*okfn)(struct sk_buff *), int hook_thresh); diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c index ce60cf0..29fe102 100644 --- a/net/netfilter/nf_queue.c +++ b/net/netfilter/nf_queue.c @@ -287,7 +287,7 @@ int nf_queue(struct sk_buff *skb, void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) { struct sk_buff *skb = entry->skb; - struct list_head *elem = &entry->elem->list; + struct nf_hook_ops *elem = entry->elem; const struct nf_afinfo *afinfo; int err; @@ -297,7 +297,7 @@ void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) /* Continue traversal iff userspace said ok... */ if (verdict == NF_REPEAT) { - elem = elem->prev; + elem = list_entry(elem->list.prev, struct nf_hook_ops, list); verdict = NF_ACCEPT; } @@ -323,7 +323,7 @@ void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) local_bh_enable(); break; case NF_QUEUE: - err = __nf_queue(skb, elem, entry->pf, entry->hook, + err = __nf_queue(skb, &elem->list, entry->pf, entry->hook, entry->indev, entry->outdev, entry->okfn, verdict >> NF_VERDICT_QBITS); if (err < 0) { -- 2.7.4