From 0edcf282b0a6f38168294264837cf7d52a2f5255 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 10 Jul 2015 18:14:30 -0500 Subject: [PATCH] netfilter: Factor out the hook list selection from nf_register_hook - Add a new function find_nf_hook_list to select the nf_hook_list - Fail nf_register_hook when asked for a per netdevice hook list when support for per netdevice hook lists is not built into the kernel. - Move the hook list head selection outside of nf_hook_mutex as nothing in the selection requires the hook list, and error handling is simpler if a mutex is not held. Signed-off-by: "Eric W. Biederman" Signed-off-by: Pablo Neira Ayuso --- net/netfilter/core.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) diff --git a/net/netfilter/core.c b/net/netfilter/core.c index c4c3b85a2538..fa4d3c111d3f 100644 --- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -62,27 +62,31 @@ EXPORT_SYMBOL(nf_hooks_needed); static DEFINE_MUTEX(nf_hook_mutex); -int nf_register_hook(struct nf_hook_ops *reg) +static struct list_head *find_nf_hook_list(const struct nf_hook_ops *reg) { - struct list_head *nf_hook_list; - struct nf_hook_ops *elem; + struct list_head *nf_hook_list = NULL; - mutex_lock(&nf_hook_mutex); - switch (reg->pf) { - case NFPROTO_NETDEV: + if (reg->pf != NFPROTO_NETDEV) + nf_hook_list = &nf_hooks[reg->pf][reg->hooknum]; + else if (reg->hooknum == NF_NETDEV_INGRESS) { #ifdef CONFIG_NETFILTER_INGRESS - if (reg->hooknum == NF_NETDEV_INGRESS) { - BUG_ON(reg->dev == NULL); + if (reg->dev) nf_hook_list = ®->dev->nf_hooks_ingress; - break; - } #endif - /* Fall through. */ - default: - nf_hook_list = &nf_hooks[reg->pf][reg->hooknum]; - break; } + return nf_hook_list; +} + +int nf_register_hook(struct nf_hook_ops *reg) +{ + struct list_head *nf_hook_list; + struct nf_hook_ops *elem; + nf_hook_list = find_nf_hook_list(reg); + if (!nf_hook_list) + return -ENOENT; + + mutex_lock(&nf_hook_mutex); list_for_each_entry(elem, nf_hook_list, list) { if (reg->priority < elem->priority) break; -- 2.11.0