1 files changed, 128 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_ecache.c b/net/netfilter/nf_conntrack_ecache.c
new file mode 100644
index 0000000..a5f5e2e
--- /dev/null
+++ b/net/netfilter/nf_conntrack_ecache.c
@@ -0,0 +1,128 @@
+/* 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_core.h>
+
+ATOMIC_NOTIFIER_HEAD(nf_conntrack_chain);
+EXPORT_SYMBOL_GPL(nf_conntrack_chain);
+
+ATOMIC_NOTIFIER_HEAD(nf_ct_expect_chain);
+EXPORT_SYMBOL_GPL(nf_ct_expect_chain);
+
+/* 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 net *net = nf_ct_net(ct);
+	struct nf_conntrack_ecache *ecache;
+
+	local_bh_disable();
+	ecache = per_cpu_ptr(net->ct.ecache, raw_smp_processor_id());
+	if (ecache->ct == ct)
+		__nf_ct_deliver_cached_events(ecache);
+	local_bh_enable();
+}
+EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events);
+
+/* Deliver cached events for old pending events, if current conntrack != old */
+void __nf_ct_event_cache_init(struct nf_conn *ct)
+{
+	struct net *net = nf_ct_net(ct);
+	struct nf_conntrack_ecache *ecache;
+
+	/* take care of delivering potentially old events */
+	ecache = per_cpu_ptr(net->ct.ecache, raw_smp_processor_id());
+	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);
+}
+EXPORT_SYMBOL_GPL(__nf_ct_event_cache_init);
+
+/* 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(struct net *net)
+{
+	struct nf_conntrack_ecache *ecache;
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		ecache = per_cpu_ptr(net->ct.ecache, cpu);
+		if (ecache->ct)
+			nf_ct_put(ecache->ct);
+	}
+}
+
+int nf_conntrack_ecache_init(struct net *net)
+{
+	net->ct.ecache = alloc_percpu(struct nf_conntrack_ecache);
+	if (!net->ct.ecache)
+		return -ENOMEM;
+	return 0;
+}
+
+void nf_conntrack_ecache_fini(struct net *net)
+{
+	free_percpu(net->ct.ecache);
+}
+
+int nf_conntrack_register_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&nf_conntrack_chain, nb);
+}
+EXPORT_SYMBOL_GPL(nf_conntrack_register_notifier);
+
+int nf_conntrack_unregister_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&nf_conntrack_chain, nb);
+}
+EXPORT_SYMBOL_GPL(nf_conntrack_unregister_notifier);
+
+int nf_ct_expect_register_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&nf_ct_expect_chain, nb);
+}
+EXPORT_SYMBOL_GPL(nf_ct_expect_register_notifier);
+
+int nf_ct_expect_unregister_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&nf_ct_expect_chain, nb);
+}
+EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier);