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author | Florian Westphal <fw@strlen.de> | 2019-04-11 16:36:41 +0200 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2019-04-12 01:47:39 +0200 |
commit | 971502d77faa50a37c89bc6d172450294ad9a5fd (patch) | |
tree | 432504faa8b09801a8b004ffb298c4ce7827a799 /net/bridge | |
parent | f12064d1b402c60c5db9c4b63d5ed6d7facb33f6 (diff) | |
download | linux-971502d77faa50a37c89bc6d172450294ad9a5fd.tar.gz linux-971502d77faa50a37c89bc6d172450294ad9a5fd.tar.bz2 linux-971502d77faa50a37c89bc6d172450294ad9a5fd.zip |
bridge: netfilter: unroll NF_HOOK helper in bridge input path
Replace NF_HOOK() based invocation of the netfilter hooks with a private
copy of nf_hook_slow().
This copy has one difference: it can return the rx handler value expected
by the stack, i.e. RX_HANDLER_CONSUMED or RX_HANDLER_PASS.
This is needed by the next patch to invoke the ebtables
"broute" table via the standard netfilter hooks rather than the custom
"br_should_route_hook" indirection that is used now.
When the skb is to be "brouted", we must return RX_HANDLER_PASS from the
bridge rx input handler, but there is no way to indicate this via
NF_HOOK(), unless perhaps by some hack such as exposing bridge_cb in the
netfilter core or a percpu flag.
text data bss dec filename
3369 56 0 3425 net/bridge/br_input.o.before
3458 40 0 3498 net/bridge/br_input.o.after
This allows removal of the "br_should_route_hook" in the next patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/bridge')
-rw-r--r-- | net/bridge/br_input.c | 55 |
1 files changed, 51 insertions, 4 deletions
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index e2f93e5c72da..4ac34fb5f943 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -16,6 +16,7 @@ #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/netfilter_bridge.h> +#include <net/netfilter/nf_queue.h> #include <linux/neighbour.h> #include <net/arp.h> #include <linux/export.h> @@ -206,6 +207,55 @@ static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_bu return 0; } +static int nf_hook_bridge_pre(struct sk_buff *skb, struct sk_buff **pskb) +{ +#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE + struct nf_hook_entries *e = NULL; + struct nf_hook_state state; + unsigned int verdict, i; + struct net *net; + int ret; + + net = dev_net(skb->dev); +#ifdef HAVE_JUMP_LABEL + if (!static_key_false(&nf_hooks_needed[NFPROTO_BRIDGE][NF_BR_PRE_ROUTING])) + goto frame_finish; +#endif + + e = rcu_dereference(net->nf.hooks_bridge[NF_BR_PRE_ROUTING]); + if (!e) + goto frame_finish; + + nf_hook_state_init(&state, NF_BR_PRE_ROUTING, + NFPROTO_BRIDGE, skb->dev, NULL, NULL, + net, br_handle_frame_finish); + + for (i = 0; i < e->num_hook_entries; i++) { + verdict = nf_hook_entry_hookfn(&e->hooks[i], skb, &state); + switch (verdict & NF_VERDICT_MASK) { + case NF_ACCEPT: + break; + case NF_DROP: + kfree_skb(skb); + return RX_HANDLER_CONSUMED; + case NF_QUEUE: + ret = nf_queue(skb, &state, e, i, verdict); + if (ret == 1) + continue; + return RX_HANDLER_CONSUMED; + default: /* STOLEN */ + return RX_HANDLER_CONSUMED; + } + } +frame_finish: + net = dev_net(skb->dev); + br_handle_frame_finish(net, NULL, skb); +#else + br_handle_frame_finish(dev_net(skb->dev), NULL, skb); +#endif + return RX_HANDLER_CONSUMED; +} + /* * Return NULL if skb is handled * note: already called with rcu_read_lock @@ -304,10 +354,7 @@ forward: if (ether_addr_equal(p->br->dev->dev_addr, dest)) skb->pkt_type = PACKET_HOST; - NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, - dev_net(skb->dev), NULL, skb, skb->dev, NULL, - br_handle_frame_finish); - break; + return nf_hook_bridge_pre(skb, pskb); default: drop: kfree_skb(skb); |