[NETFILTER]: nf_conntrack: split out the event cache

This patch splits out the event cache into its own file
nf_conntrack_ecache.c

Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 91 insertions, 0 deletions

diff --git a/net/netfilter/nf_conntrack_ecache.c b/net/netfilter/nf_conntrack_ecache.c
new file mode 100644
index 000000000000..35763e96fddb
--- /dev/null
+++ b/net/netfilter/nf_conntrack_ecache.c
@@ -0,0 +1,91 @@
+/* Event cache for netfilter. */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/netfilter.h>
+#include <linux/skbuff.h>
+#include <linux/vmalloc.h>
+#include <linux/stddef.h>
+#include <linux/err.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_l3proto.h>
+#include <net/netfilter/nf_conntrack_protocol.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_core.h>
+
+ATOMIC_NOTIFIER_HEAD(nf_conntrack_chain);
+ATOMIC_NOTIFIER_HEAD(nf_conntrack_expect_chain);
+
+DEFINE_PER_CPU(struct nf_conntrack_ecache, nf_conntrack_ecache);
+
+/* deliver cached events and clear cache entry - must be called with locally
+ * disabled softirqs */
+static inline void
+__nf_ct_deliver_cached_events(struct nf_conntrack_ecache *ecache)
+{
+	if (nf_ct_is_confirmed(ecache->ct) && !nf_ct_is_dying(ecache->ct)
+	    && ecache->events)
+		atomic_notifier_call_chain(&nf_conntrack_chain, ecache->events,
+				    ecache->ct);
+
+	ecache->events = 0;
+	nf_ct_put(ecache->ct);
+	ecache->ct = NULL;
+}
+
+/* Deliver all cached events for a particular conntrack. This is called
+ * by code prior to async packet handling for freeing the skb */
+void nf_ct_deliver_cached_events(const struct nf_conn *ct)
+{
+	struct nf_conntrack_ecache *ecache;
+
+	local_bh_disable();
+	ecache = &__get_cpu_var(nf_conntrack_ecache);
+	if (ecache->ct == ct)
+		__nf_ct_deliver_cached_events(ecache);
+	local_bh_enable();
+}
+
+/* Deliver cached events for old pending events, if current conntrack != old */
+void __nf_ct_event_cache_init(struct nf_conn *ct)
+{
+	struct nf_conntrack_ecache *ecache;
+
+	/* take care of delivering potentially old events */
+	ecache = &__get_cpu_var(nf_conntrack_ecache);
+	BUG_ON(ecache->ct == ct);
+	if (ecache->ct)
+		__nf_ct_deliver_cached_events(ecache);
+	/* initialize for this conntrack/packet */
+	ecache->ct = ct;
+	nf_conntrack_get(&ct->ct_general);
+}
+
+/* flush the event cache - touches other CPU's data and must not be called
+ * while packets are still passing through the code */
+void nf_ct_event_cache_flush(void)
+{
+	struct nf_conntrack_ecache *ecache;
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		ecache = &per_cpu(nf_conntrack_ecache, cpu);
+		if (ecache->ct)
+			nf_ct_put(ecache->ct);
+	}
+}
+