This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / net / netfilter / nf_conntrack_ecache.c

diff --git a/net/netfilter/nf_conntrack_ecache.c b/net/netfilter/nf_conntrack_ecache.c
new file mode 100644 (file)
index 0000000..1a223e0
--- /dev/null
+++ b/net/netfilter/nf_conntrack_ecache.c
@@ -0,0 +1,93 @@
+/* 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_conntrack_expect_chain);
+EXPORT_SYMBOL_GPL(nf_conntrack_expect_chain);
+
+DEFINE_PER_CPU(struct nf_conntrack_ecache, nf_conntrack_ecache);
+EXPORT_PER_CPU_SYMBOL_GPL(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();
+}
+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 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);
+}
+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(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);
+       }
+}
+