1 files changed, 78 insertions, 11 deletions

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 14235b144cb5..5f72b94b4918 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/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;