---

yaml
---
r: 150942
b: refs/heads/master
c: dd7669a
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d219dce76c64f2c883dad0537fa09a56d5ff0a10
+refs/heads/master: dd7669a92c6066b2b31bae7e04cd787092920883

trunk/include/net/netfilter/nf_conntrack.h

@@ -201,6 +201,8 @@ extern struct nf_conntrack_tuple_hash *
 __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple);
 
 extern void nf_conntrack_hash_insert(struct nf_conn *ct);
+extern void nf_ct_delete_from_lists(struct nf_conn *ct);
+extern void nf_ct_insert_dying_list(struct nf_conn *ct);
 
 extern void nf_conntrack_flush_report(struct net *net, u32 pid, int report);
 

trunk/include/net/netfilter/nf_conntrack_ecache.h

@@ -32,6 +32,8 @@ enum ip_conntrack_expect_events {
 
 struct nf_conntrack_ecache {
 	unsigned long cache;		/* bitops want long */
+	unsigned long missed;		/* missed events */
+	u32 pid;			/* netlink pid of destroyer */
 };
 
 static inline struct nf_conntrack_ecache *
@@ -84,14 +86,16 @@ nf_conntrack_event_cache(enum ip_conntrack_events event, struct nf_conn *ct)
 	set_bit(event, &e->cache);
 }
 
-static inline void
+static inline int
 nf_conntrack_eventmask_report(unsigned int eventmask,
 			      struct nf_conn *ct,
 			      u32 pid,
 			      int report)
 {
+	int ret = 0;
 	struct net *net = nf_ct_net(ct);
 	struct nf_ct_event_notifier *notify;
+	struct nf_conntrack_ecache *e;
 
 	rcu_read_lock();
 	notify = rcu_dereference(nf_conntrack_event_cb);
@@ -101,29 +105,52 @@ nf_conntrack_eventmask_report(unsigned int eventmask,
 	if (!net->ct.sysctl_events)
 		goto out_unlock;
 
+	e = nf_ct_ecache_find(ct);
+	if (e == NULL)
+		goto out_unlock;
+
 	if (nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct)) {
 		struct nf_ct_event item = {
 			.ct 	= ct,
-			.pid	= pid,
+			.pid	= e->pid ? e->pid : pid,
 			.report = report
 		};
-		notify->fcn(eventmask, &item);
+		/* This is a resent of a destroy event? If so, skip missed */
+		unsigned long missed = e->pid ? 0 : e->missed;
+
+		ret = notify->fcn(eventmask | missed, &item);
+		if (unlikely(ret < 0 || missed)) {
+			spin_lock_bh(&ct->lock);
+			if (ret < 0) {
+				/* This is a destroy event that has been
+				 * triggered by a process, we store the PID
+				 * to include it in the retransmission. */
+				if (eventmask & (1 << IPCT_DESTROY) &&
+				    e->pid == 0 && pid != 0)
+					e->pid = pid;
+				else
+					e->missed |= eventmask;
+			} else
+				e->missed &= ~missed;
+			spin_unlock_bh(&ct->lock);
+		}
 	}
 out_unlock:
 	rcu_read_unlock();
+	return ret;
 }
 
-static inline void
+static inline int
 nf_conntrack_event_report(enum ip_conntrack_events event, struct nf_conn *ct,
 			  u32 pid, int report)
 {
-	nf_conntrack_eventmask_report(1 << event, ct, pid, report);
+	return nf_conntrack_eventmask_report(1 << event, ct, pid, report);
 }
 
-static inline void
+static inline int
 nf_conntrack_event(enum ip_conntrack_events event, struct nf_conn *ct)
 {
-	nf_conntrack_eventmask_report(1 << event, ct, 0, 0);
+	return nf_conntrack_eventmask_report(1 << event, ct, 0, 0);
 }
 
 struct nf_exp_event {
@@ -183,16 +210,16 @@ extern void nf_conntrack_ecache_fini(struct net *net);
 
 static inline void nf_conntrack_event_cache(enum ip_conntrack_events event,
 					    struct nf_conn *ct) {}
-static inline void nf_conntrack_eventmask_report(unsigned int eventmask,
-						 struct nf_conn *ct,
-						 u32 pid,
-						 int report) {}
-static inline void nf_conntrack_event(enum ip_conntrack_events event,
-				      struct nf_conn *ct) {}
-static inline void nf_conntrack_event_report(enum ip_conntrack_events event,
-					     struct nf_conn *ct,
-					     u32 pid,
-					     int report) {}
+static inline int nf_conntrack_eventmask_report(unsigned int eventmask,
+						struct nf_conn *ct,
+						u32 pid,
+						int report) { return 0; }
+static inline int nf_conntrack_event(enum ip_conntrack_events event,
+				     struct nf_conn *ct) { return 0; }
+static inline int nf_conntrack_event_report(enum ip_conntrack_events event,
+					    struct nf_conn *ct,
+					    u32 pid,
+					    int report) { return 0; }
 static inline void nf_ct_deliver_cached_events(const struct nf_conn *ct) {}
 static inline void nf_ct_expect_event(enum ip_conntrack_expect_events event,
 				      struct nf_conntrack_expect *exp) {}

trunk/include/net/netns/conntrack.h

@@ -14,8 +14,10 @@ struct netns_ct {
 	struct hlist_nulls_head	*hash;
 	struct hlist_head	*expect_hash;
 	struct hlist_nulls_head	unconfirmed;
+	struct hlist_nulls_head	dying;
 	struct ip_conntrack_stat *stat;
 	int			sysctl_events;
+	unsigned int		sysctl_events_retry_timeout;
 	int			sysctl_acct;
 	int			sysctl_checksum;
 	unsigned int		sysctl_log_invalid; /* Log invalid packets */

trunk/net/netfilter/nf_conntrack_core.c

@@ -183,10 +183,6 @@ destroy_conntrack(struct nf_conntrack *nfct)
 	NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 	NF_CT_ASSERT(!timer_pending(&ct->timeout));
 
-	if (!test_bit(IPS_DYING_BIT, &ct->status))
-		nf_conntrack_event(IPCT_DESTROY, ct);
-	set_bit(IPS_DYING_BIT, &ct->status);
-
 	/* To make sure we don't get any weird locking issues here:
 	 * destroy_conntrack() MUST NOT be called with a write lock
 	 * to nf_conntrack_lock!!! -HW */
@@ -220,9 +216,8 @@ destroy_conntrack(struct nf_conntrack *nfct)
 	nf_conntrack_free(ct);
 }
 
-static void death_by_timeout(unsigned long ul_conntrack)
+void nf_ct_delete_from_lists(struct nf_conn *ct)
 {
-	struct nf_conn *ct = (void *)ul_conntrack;
 	struct net *net = nf_ct_net(ct);
 
 	nf_ct_helper_destroy(ct);
@@ -232,6 +227,59 @@ static void death_by_timeout(unsigned long ul_conntrack)
 	NF_CT_STAT_INC(net, delete_list);
 	clean_from_lists(ct);
 	spin_unlock_bh(&nf_conntrack_lock);
+}
+EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists);
+
+static void death_by_event(unsigned long ul_conntrack)
+{
+	struct nf_conn *ct = (void *)ul_conntrack;
+	struct net *net = nf_ct_net(ct);
+
+	if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) {
+		/* bad luck, let's retry again */
+		ct->timeout.expires = jiffies +
+			(random32() % net->ct.sysctl_events_retry_timeout);
+		add_timer(&ct->timeout);
+		return;
+	}
+	/* we've got the event delivered, now it's dying */
+	set_bit(IPS_DYING_BIT, &ct->status);
+	spin_lock(&nf_conntrack_lock);
+	hlist_nulls_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
+	spin_unlock(&nf_conntrack_lock);
+	nf_ct_put(ct);
+}
+
+void nf_ct_insert_dying_list(struct nf_conn *ct)
+{
+	struct net *net = nf_ct_net(ct);
+
+	/* add this conntrack to the dying list */
+	spin_lock_bh(&nf_conntrack_lock);
+	hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
+			     &net->ct.dying);
+	spin_unlock_bh(&nf_conntrack_lock);
+	/* set a new timer to retry event delivery */
+	setup_timer(&ct->timeout, death_by_event, (unsigned long)ct);
+	ct->timeout.expires = jiffies +
+		(random32() % net->ct.sysctl_events_retry_timeout);
+	add_timer(&ct->timeout);
+}
+EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list);
+
+static void death_by_timeout(unsigned long ul_conntrack)
+{
+	struct nf_conn *ct = (void *)ul_conntrack;
+
+	if (!test_bit(IPS_DYING_BIT, &ct->status) &&
+	    unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) {
+		/* destroy event was not delivered */
+		nf_ct_delete_from_lists(ct);
+		nf_ct_insert_dying_list(ct);
+		return;
+	}
+	set_bit(IPS_DYING_BIT, &ct->status);
+	nf_ct_delete_from_lists(ct);
 	nf_ct_put(ct);
 }
 
@@ -982,11 +1030,13 @@ static int kill_report(struct nf_conn *i, void *data)
 {
 	struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data;
 
-	/* get_next_corpse sets the dying bit for us */
-	nf_conntrack_event_report(IPCT_DESTROY,
-				  i,
-				  fr->pid,
-				  fr->report);
+	/* If we fail to deliver the event, death_by_timeout() will retry */
+	if (nf_conntrack_event_report(IPCT_DESTROY, i,
+				      fr->pid, fr->report) < 0)
+		return 1;
+
+	/* Avoid the delivery of the destroy event in death_by_timeout(). */
+	set_bit(IPS_DYING_BIT, &i->status);
 	return 1;
 }
 
@@ -1015,6 +1065,21 @@ void nf_conntrack_flush_report(struct net *net, u32 pid, int report)
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report);
 
+static void nf_ct_release_dying_list(void)
+{
+	struct nf_conntrack_tuple_hash *h;
+	struct nf_conn *ct;
+	struct hlist_nulls_node *n;
+
+	spin_lock_bh(&nf_conntrack_lock);
+	hlist_nulls_for_each_entry(h, n, &init_net.ct.dying, hnnode) {
+		ct = nf_ct_tuplehash_to_ctrack(h);
+		/* never fails to remove them, no listeners at this point */
+		nf_ct_kill(ct);
+	}
+	spin_unlock_bh(&nf_conntrack_lock);
+}
+
 static void nf_conntrack_cleanup_init_net(void)
 {
 	nf_conntrack_helper_fini();
@@ -1026,6 +1091,7 @@ static void nf_conntrack_cleanup_net(struct net *net)
 {
  i_see_dead_people:
 	nf_ct_iterate_cleanup(net, kill_all, NULL);
+	nf_ct_release_dying_list();
 	if (atomic_read(&net->ct.count) != 0) {
 		schedule();
 		goto i_see_dead_people;
@@ -1207,6 +1273,7 @@ static int nf_conntrack_init_net(struct net *net)
 
 	atomic_set(&net->ct.count, 0);
 	INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, 0);
+	INIT_HLIST_NULLS_HEAD(&net->ct.dying, 0);
 	net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
 	if (!net->ct.stat) {
 		ret = -ENOMEM;

trunk/net/netfilter/nf_conntrack_ecache.c

@@ -56,8 +56,21 @@ void nf_ct_deliver_cached_events(struct nf_conn *ct)
 			.pid	= 0,
 			.report	= 0
 		};
-
-		notify->fcn(events, &item);
+		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:
@@ -133,6 +146,7 @@ EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier);
 
 #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[] = {
@@ -144,6 +158,14 @@ static struct ctl_table event_sysctl_table[] = {
 		.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 */
@@ -165,6 +187,7 @@ static int nf_conntrack_event_init_sysctl(struct net *net)
 		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,
@@ -205,6 +228,7 @@ int nf_conntrack_ecache_init(struct net *net)
 	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);

trunk/net/netfilter/nf_conntrack_netlink.c

@@ -463,6 +463,7 @@ ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item)
 	struct sk_buff *skb;
 	unsigned int type;
 	unsigned int flags = 0, group;
+	int err;
 
 	/* ignore our fake conntrack entry */
 	if (ct == &nf_conntrack_untracked)
@@ -558,7 +559,10 @@ ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item)
 	rcu_read_unlock();
 
 	nlmsg_end(skb, nlh);
-	nfnetlink_send(skb, item->pid, group, item->report, GFP_ATOMIC);
+	err = nfnetlink_send(skb, item->pid, group, item->report, GFP_ATOMIC);
+	if (err == -ENOBUFS || err == -EAGAIN)
+		return -ENOBUFS;
+
 	return 0;
 
 nla_put_failure:
@@ -798,10 +802,15 @@ ctnetlink_del_conntrack(struct sock *ctnl, struct sk_buff *skb,
 		}
 	}
 
-	nf_conntrack_event_report(IPCT_DESTROY,
-				  ct,
-				  NETLINK_CB(skb).pid,
-				  nlmsg_report(nlh));
+	if (nf_conntrack_event_report(IPCT_DESTROY, ct,
+				      NETLINK_CB(skb).pid,
+				      nlmsg_report(nlh)) < 0) {
+		nf_ct_delete_from_lists(ct);
+		/* we failed to report the event, try later */
+		nf_ct_insert_dying_list(ct);
+		nf_ct_put(ct);
+		return 0;
+	}
 
 	/* death_by_timeout would report the event again */
 	set_bit(IPS_DYING_BIT, &ct->status);