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authorPablo Neira <pablo@netfilter.org>2015-05-13 18:19:38 +0200
committerDavid S. Miller <davem@davemloft.net>2015-05-14 01:10:05 -0400
commite687ad60af09010936bbd0b2a3b5d90a8ee8353c (patch)
treec4900d74376c475169c354e88c7c553ce0c2f46d /net/netfilter/core.c
parentnet: add CONFIG_NET_INGRESS to enable ingress filtering (diff)
downloadlinux-dev-e687ad60af09010936bbd0b2a3b5d90a8ee8353c.tar.xz
linux-dev-e687ad60af09010936bbd0b2a3b5d90a8ee8353c.zip
netfilter: add netfilter ingress hook after handle_ing() under unique static key
This patch adds the Netfilter ingress hook just after the existing tc ingress hook, that seems to be the consensus solution for this. Note that the Netfilter hook resides under the global static key that enables ingress filtering. Nonetheless, Netfilter still also has its own static key for minimal impact on the existing handle_ing(). * Without this patch: Result: OK: 6216490(c6216338+d152) usec, 100000000 (60byte,0frags) 16086246pps 7721Mb/sec (7721398080bps) errors: 100000000 42.46% kpktgend_0 [kernel.kallsyms] [k] __netif_receive_skb_core 25.92% kpktgend_0 [kernel.kallsyms] [k] kfree_skb 7.81% kpktgend_0 [pktgen] [k] pktgen_thread_worker 5.62% kpktgend_0 [kernel.kallsyms] [k] ip_rcv 2.70% kpktgend_0 [kernel.kallsyms] [k] netif_receive_skb_internal 2.34% kpktgend_0 [kernel.kallsyms] [k] netif_receive_skb_sk 1.44% kpktgend_0 [kernel.kallsyms] [k] __build_skb * With this patch: Result: OK: 6214833(c6214731+d101) usec, 100000000 (60byte,0frags) 16090536pps 7723Mb/sec (7723457280bps) errors: 100000000 41.23% kpktgend_0 [kernel.kallsyms] [k] __netif_receive_skb_core 26.57% kpktgend_0 [kernel.kallsyms] [k] kfree_skb 7.72% kpktgend_0 [pktgen] [k] pktgen_thread_worker 5.55% kpktgend_0 [kernel.kallsyms] [k] ip_rcv 2.78% kpktgend_0 [kernel.kallsyms] [k] netif_receive_skb_internal 2.06% kpktgend_0 [kernel.kallsyms] [k] netif_receive_skb_sk 1.43% kpktgend_0 [kernel.kallsyms] [k] __build_skb * Without this patch + tc ingress: tc filter add dev eth4 parent ffff: protocol ip prio 1 \ u32 match ip dst 4.3.2.1/32 Result: OK: 9269001(c9268821+d179) usec, 100000000 (60byte,0frags) 10788648pps 5178Mb/sec (5178551040bps) errors: 100000000 40.99% kpktgend_0 [kernel.kallsyms] [k] __netif_receive_skb_core 17.50% kpktgend_0 [kernel.kallsyms] [k] kfree_skb 11.77% kpktgend_0 [cls_u32] [k] u32_classify 5.62% kpktgend_0 [kernel.kallsyms] [k] tc_classify_compat 5.18% kpktgend_0 [pktgen] [k] pktgen_thread_worker 3.23% kpktgend_0 [kernel.kallsyms] [k] tc_classify 2.97% kpktgend_0 [kernel.kallsyms] [k] ip_rcv 1.83% kpktgend_0 [kernel.kallsyms] [k] netif_receive_skb_internal 1.50% kpktgend_0 [kernel.kallsyms] [k] netif_receive_skb_sk 0.99% kpktgend_0 [kernel.kallsyms] [k] __build_skb * With this patch + tc ingress: tc filter add dev eth4 parent ffff: protocol ip prio 1 \ u32 match ip dst 4.3.2.1/32 Result: OK: 9308218(c9308091+d126) usec, 100000000 (60byte,0frags) 10743194pps 5156Mb/sec (5156733120bps) errors: 100000000 42.01% kpktgend_0 [kernel.kallsyms] [k] __netif_receive_skb_core 17.78% kpktgend_0 [kernel.kallsyms] [k] kfree_skb 11.70% kpktgend_0 [cls_u32] [k] u32_classify 5.46% kpktgend_0 [kernel.kallsyms] [k] tc_classify_compat 5.16% kpktgend_0 [pktgen] [k] pktgen_thread_worker 2.98% kpktgend_0 [kernel.kallsyms] [k] ip_rcv 2.84% kpktgend_0 [kernel.kallsyms] [k] tc_classify 1.96% kpktgend_0 [kernel.kallsyms] [k] netif_receive_skb_internal 1.57% kpktgend_0 [kernel.kallsyms] [k] netif_receive_skb_sk Note that the results are very similar before and after. I can see gcc gets the code under the ingress static key out of the hot path. Then, on that cold branch, it generates the code to accomodate the netfilter ingress static key. My explanation for this is that this reduces the pressure on the instruction cache for non-users as the new code is out of the hot path, and it comes with minimal impact for tc ingress users. Using gcc version 4.8.4 on: Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 8 [...] L1d cache: 16K L1i cache: 64K L2 cache: 2048K L3 cache: 8192K Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netfilter/core.c')
-rw-r--r--net/netfilter/core.c31
1 files changed, 30 insertions, 1 deletions
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index e418cfd603c0..653e32eac08c 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -64,10 +64,27 @@ static DEFINE_MUTEX(nf_hook_mutex);
int nf_register_hook(struct nf_hook_ops *reg)
{
+ struct list_head *nf_hook_list;
struct nf_hook_ops *elem;
mutex_lock(&nf_hook_mutex);
- list_for_each_entry(elem, &nf_hooks[reg->pf][reg->hooknum], list) {
+ switch (reg->pf) {
+ case NFPROTO_NETDEV:
+#ifdef CONFIG_NETFILTER_INGRESS
+ if (reg->hooknum == NF_NETDEV_INGRESS) {
+ BUG_ON(reg->dev == NULL);
+ nf_hook_list = &reg->dev->nf_hooks_ingress;
+ net_inc_ingress_queue();
+ break;
+ }
+#endif
+ /* Fall through. */
+ default:
+ nf_hook_list = &nf_hooks[reg->pf][reg->hooknum];
+ break;
+ }
+
+ list_for_each_entry(elem, nf_hook_list, list) {
if (reg->priority < elem->priority)
break;
}
@@ -85,6 +102,18 @@ void nf_unregister_hook(struct nf_hook_ops *reg)
mutex_lock(&nf_hook_mutex);
list_del_rcu(&reg->list);
mutex_unlock(&nf_hook_mutex);
+ switch (reg->pf) {
+ case NFPROTO_NETDEV:
+#ifdef CONFIG_NETFILTER_INGRESS
+ if (reg->hooknum == NF_NETDEV_INGRESS) {
+ net_dec_ingress_queue();
+ break;
+ }
+ break;
+#endif
+ default:
+ break;
+ }
#ifdef HAVE_JUMP_LABEL
static_key_slow_dec(&nf_hooks_needed[reg->pf][reg->hooknum]);
#endif