diff options
Diffstat (limited to 'net/netfilter/nf_conntrack_ecache.c')
-rw-r--r-- | net/netfilter/nf_conntrack_ecache.c | 93 |
1 files changed, 93 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..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); + } +} + |