#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>
+#include <net/netfilter/nf_conntrack_extend.h>
-ATOMIC_NOTIFIER_HEAD(nf_conntrack_chain);
-EXPORT_SYMBOL_GPL(nf_conntrack_chain);
+static DEFINE_MUTEX(nf_ct_ecache_mutex);
-ATOMIC_NOTIFIER_HEAD(nf_ct_expect_chain);
-EXPORT_SYMBOL_GPL(nf_ct_expect_chain);
+struct nf_ct_event_notifier *nf_conntrack_event_cb __read_mostly;
+EXPORT_SYMBOL_GPL(nf_conntrack_event_cb);
+
+struct nf_exp_event_notifier *nf_expect_event_cb __read_mostly;
+EXPORT_SYMBOL_GPL(nf_expect_event_cb);
/* 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)
+void nf_ct_deliver_cached_events(struct nf_conn *ct)
{
- 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;
+ unsigned long events;
+ struct nf_ct_event_notifier *notify;
+ struct nf_conntrack_ecache *e;
+
+ rcu_read_lock();
+ notify = rcu_dereference(nf_conntrack_event_cb);
+ if (notify == NULL)
+ goto out_unlock;
+
+ e = nf_ct_ecache_find(ct);
+ if (e == NULL)
+ goto out_unlock;
+
+ events = xchg(&e->cache, 0);
+
+ if (nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct) && events) {
+ struct nf_ct_event item = {
+ .ct = ct,
+ .pid = 0,
+ .report = 0
+ };
+ int ret;
+ /* We make a copy of the missed event cache without taking
+ * the lock, thus we may send missed events twice. However,
+ * this does not harm and it happens very rarely. */
+ unsigned long missed = e->missed;
+
+ ret = notify->fcn(events | missed, &item);
+ if (unlikely(ret < 0 || missed)) {
+ spin_lock_bh(&ct->lock);
+ if (ret < 0)
+ e->missed |= events;
+ else
+ e->missed &= ~missed;
+ spin_unlock_bh(&ct->lock);
+ }
+ }
+
+out_unlock:
+ rcu_read_unlock();
}
+EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events);
-/* 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)
+int nf_conntrack_register_notifier(struct nf_ct_event_notifier *new)
{
- 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();
+ int ret = 0;
+ struct nf_ct_event_notifier *notify;
+
+ mutex_lock(&nf_ct_ecache_mutex);
+ notify = rcu_dereference(nf_conntrack_event_cb);
+ if (notify != NULL) {
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ rcu_assign_pointer(nf_conntrack_event_cb, new);
+ mutex_unlock(&nf_ct_ecache_mutex);
+ return ret;
+
+out_unlock:
+ mutex_unlock(&nf_ct_ecache_mutex);
+ return ret;
}
-EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events);
+EXPORT_SYMBOL_GPL(nf_conntrack_register_notifier);
-/* Deliver cached events for old pending events, if current conntrack != old */
-void __nf_ct_event_cache_init(struct nf_conn *ct)
+void nf_conntrack_unregister_notifier(struct nf_ct_event_notifier *new)
{
- 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);
+ struct nf_ct_event_notifier *notify;
+
+ mutex_lock(&nf_ct_ecache_mutex);
+ notify = rcu_dereference(nf_conntrack_event_cb);
+ BUG_ON(notify != new);
+ rcu_assign_pointer(nf_conntrack_event_cb, NULL);
+ mutex_unlock(&nf_ct_ecache_mutex);
}
-EXPORT_SYMBOL_GPL(__nf_ct_event_cache_init);
+EXPORT_SYMBOL_GPL(nf_conntrack_unregister_notifier);
-/* 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)
+int nf_ct_expect_register_notifier(struct nf_exp_event_notifier *new)
{
- struct nf_conntrack_ecache *ecache;
- int cpu;
+ int ret = 0;
+ struct nf_exp_event_notifier *notify;
- for_each_possible_cpu(cpu) {
- ecache = per_cpu_ptr(net->ct.ecache, cpu);
- if (ecache->ct)
- nf_ct_put(ecache->ct);
+ mutex_lock(&nf_ct_ecache_mutex);
+ notify = rcu_dereference(nf_expect_event_cb);
+ if (notify != NULL) {
+ ret = -EBUSY;
+ goto out_unlock;
}
+ rcu_assign_pointer(nf_expect_event_cb, new);
+ mutex_unlock(&nf_ct_ecache_mutex);
+ return ret;
+
+out_unlock:
+ mutex_unlock(&nf_ct_ecache_mutex);
+ return ret;
}
+EXPORT_SYMBOL_GPL(nf_ct_expect_register_notifier);
-int nf_conntrack_ecache_init(struct net *net)
+void nf_ct_expect_unregister_notifier(struct nf_exp_event_notifier *new)
{
- net->ct.ecache = alloc_percpu(struct nf_conntrack_ecache);
- if (!net->ct.ecache)
- return -ENOMEM;
- return 0;
+ struct nf_exp_event_notifier *notify;
+
+ mutex_lock(&nf_ct_ecache_mutex);
+ notify = rcu_dereference(nf_expect_event_cb);
+ BUG_ON(notify != new);
+ rcu_assign_pointer(nf_expect_event_cb, NULL);
+ mutex_unlock(&nf_ct_ecache_mutex);
}
+EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier);
-void nf_conntrack_ecache_fini(struct net *net)
+#define NF_CT_EVENTS_DEFAULT 1
+static int nf_ct_events __read_mostly = NF_CT_EVENTS_DEFAULT;
+static int nf_ct_events_retry_timeout __read_mostly = 15*HZ;
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table event_sysctl_table[] = {
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "nf_conntrack_events",
+ .data = &init_net.ct.sysctl_events,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "nf_conntrack_events_retry_timeout",
+ .data = &init_net.ct.sysctl_events_retry_timeout,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_jiffies,
+ },
+ {}
+};
+#endif /* CONFIG_SYSCTL */
+
+static struct nf_ct_ext_type event_extend __read_mostly = {
+ .len = sizeof(struct nf_conntrack_ecache),
+ .align = __alignof__(struct nf_conntrack_ecache),
+ .id = NF_CT_EXT_ECACHE,
+};
+
+#ifdef CONFIG_SYSCTL
+static int nf_conntrack_event_init_sysctl(struct net *net)
{
- free_percpu(net->ct.ecache);
+ struct ctl_table *table;
+
+ table = kmemdup(event_sysctl_table, sizeof(event_sysctl_table),
+ GFP_KERNEL);
+ if (!table)
+ goto out;
+
+ table[0].data = &net->ct.sysctl_events;
+ table[1].data = &net->ct.sysctl_events_retry_timeout;
+
+ net->ct.event_sysctl_header =
+ register_net_sysctl_table(net,
+ nf_net_netfilter_sysctl_path, table);
+ if (!net->ct.event_sysctl_header) {
+ printk(KERN_ERR "nf_ct_event: can't register to sysctl.\n");
+ goto out_register;
+ }
+ return 0;
+
+out_register:
+ kfree(table);
+out:
+ return -ENOMEM;
}
-int nf_conntrack_register_notifier(struct notifier_block *nb)
+static void nf_conntrack_event_fini_sysctl(struct net *net)
{
- return atomic_notifier_chain_register(&nf_conntrack_chain, nb);
+ struct ctl_table *table;
+
+ table = net->ct.event_sysctl_header->ctl_table_arg;
+ unregister_net_sysctl_table(net->ct.event_sysctl_header);
+ kfree(table);
+}
+#else
+static int nf_conntrack_event_init_sysctl(struct net *net)
+{
+ return 0;
}
-EXPORT_SYMBOL_GPL(nf_conntrack_register_notifier);
-int nf_conntrack_unregister_notifier(struct notifier_block *nb)
+static void nf_conntrack_event_fini_sysctl(struct net *net)
{
- return atomic_notifier_chain_unregister(&nf_conntrack_chain, nb);
}
-EXPORT_SYMBOL_GPL(nf_conntrack_unregister_notifier);
+#endif /* CONFIG_SYSCTL */
-int nf_ct_expect_register_notifier(struct notifier_block *nb)
+int nf_conntrack_ecache_init(struct net *net)
{
- return atomic_notifier_chain_register(&nf_ct_expect_chain, nb);
+ int ret;
+
+ net->ct.sysctl_events = nf_ct_events;
+ net->ct.sysctl_events_retry_timeout = nf_ct_events_retry_timeout;
+
+ if (net_eq(net, &init_net)) {
+ ret = nf_ct_extend_register(&event_extend);
+ if (ret < 0) {
+ printk(KERN_ERR "nf_ct_event: Unable to register "
+ "event extension.\n");
+ goto out_extend_register;
+ }
+ }
+
+ ret = nf_conntrack_event_init_sysctl(net);
+ if (ret < 0)
+ goto out_sysctl;
+
+ return 0;
+
+out_sysctl:
+ if (net_eq(net, &init_net))
+ nf_ct_extend_unregister(&event_extend);
+out_extend_register:
+ return ret;
}
-EXPORT_SYMBOL_GPL(nf_ct_expect_register_notifier);
-int nf_ct_expect_unregister_notifier(struct notifier_block *nb)
+void nf_conntrack_ecache_fini(struct net *net)
{
- return atomic_notifier_chain_unregister(&nf_ct_expect_chain, nb);
+ nf_conntrack_event_fini_sysctl(net);
+ if (net_eq(net, &init_net))
+ nf_ct_extend_unregister(&event_extend);
}
-EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier);
git.samba.org / sfrench / cifs-2.6.git / blobdiff