diff options
author | Florian Westphal <fw@strlen.de> | 2016-09-21 11:35:01 -0400 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-09-24 21:25:48 +0200 |
commit | c5136b15ea364124299c8a9ba96b300e96061e3a (patch) | |
tree | c5ffa93a950d60bdc5bc0690743c5bc806cd0904 /net/bridge/br_netfilter_hooks.c | |
parent | 50f4c7b73f831a53fa9ddeb9bdf4cfb5b23d3aa7 (diff) | |
download | linux-c5136b15ea364124299c8a9ba96b300e96061e3a.tar.bz2 |
netfilter: bridge: add and use br_nf_hook_thresh
This replaces the last uses of NF_HOOK_THRESH().
Followup patch will remove it and rename nf_hook_thresh.
The reason is that inet (non-bridge) netfilter no longer invokes the
hooks from hooks, so we do no longer need the thresh value to skip hooks
with a lower priority.
The bridge netfilter however may need to do this. br_nf_hook_thresh is a
wrapper that is supposed to do this, i.e. only call hooks with a
priority that exceeds NF_BR_PRI_BRNF.
It's used only in the recursion cases of br_netfilter. It invokes
nf_hook_slow while holding an rcu read-side critical section to make a
future cleanup simpler.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/bridge/br_netfilter_hooks.c')
-rw-r--r-- | net/bridge/br_netfilter_hooks.c | 60 |
1 files changed, 51 insertions, 9 deletions
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index 77e7f69bf80d..6029af47377d 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -30,6 +30,7 @@ #include <linux/netfilter_ipv6.h> #include <linux/netfilter_arp.h> #include <linux/in_route.h> +#include <linux/rculist.h> #include <linux/inetdevice.h> #include <net/ip.h> @@ -395,11 +396,10 @@ bridged_dnat: skb->dev = nf_bridge->physindev; nf_bridge_update_protocol(skb); nf_bridge_push_encap_header(skb); - NF_HOOK_THRESH(NFPROTO_BRIDGE, - NF_BR_PRE_ROUTING, - net, sk, skb, skb->dev, NULL, - br_nf_pre_routing_finish_bridge, - 1); + br_nf_hook_thresh(NF_BR_PRE_ROUTING, + net, sk, skb, skb->dev, + NULL, + br_nf_pre_routing_finish); return 0; } ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr); @@ -417,10 +417,8 @@ bridged_dnat: skb->dev = nf_bridge->physindev; nf_bridge_update_protocol(skb); nf_bridge_push_encap_header(skb); - NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, net, sk, skb, - skb->dev, NULL, - br_handle_frame_finish, 1); - + br_nf_hook_thresh(NF_BR_PRE_ROUTING, net, sk, skb, skb->dev, NULL, + br_handle_frame_finish); return 0; } @@ -992,6 +990,50 @@ static struct notifier_block brnf_notifier __read_mostly = { .notifier_call = brnf_device_event, }; +/* recursively invokes nf_hook_slow (again), skipping already-called + * hooks (< NF_BR_PRI_BRNF). + * + * Called with rcu read lock held. + */ +int br_nf_hook_thresh(unsigned int hook, struct net *net, + struct sock *sk, struct sk_buff *skb, + struct net_device *indev, + struct net_device *outdev, + int (*okfn)(struct net *, struct sock *, + struct sk_buff *)) +{ + struct nf_hook_ops *elem; + struct nf_hook_state state; + struct list_head *head; + int ret; + + head = &net->nf.hooks[NFPROTO_BRIDGE][hook]; + + list_for_each_entry_rcu(elem, head, list) { + struct nf_hook_ops *next; + + next = list_entry_rcu(list_next_rcu(&elem->list), + struct nf_hook_ops, list); + if (next->priority <= NF_BR_PRI_BRNF) + continue; + } + + if (&elem->list == head) + return okfn(net, sk, skb); + + /* We may already have this, but read-locks nest anyway */ + rcu_read_lock(); + nf_hook_state_init(&state, head, hook, NF_BR_PRI_BRNF + 1, + NFPROTO_BRIDGE, indev, outdev, sk, net, okfn); + + ret = nf_hook_slow(skb, &state); + rcu_read_unlock(); + if (ret == 1) + ret = okfn(net, sk, skb); + + return ret; +} + #ifdef CONFIG_SYSCTL static int brnf_sysctl_call_tables(struct ctl_table *ctl, int write, |