[PATCH nf] netfilter: nf_flow_table: do not remove offload when other netns's interface is down

[Taehee Yoo <ap420073@xxxxxxxxx>]

When interface is down, offload cleanup function(nf_flow_table_do_cleanup)
is called and that checks whether interface index of offload and
index of link down interface is same. but only interface index checking
is not enough because flowtable is not pernet list.
So that, if other netns's interface that has index is same with offload
is down, that offload will be removed.
This patch adds netns checking code to the offload cleanup routine.
And it also removes unnecessary parameter of nf_flow_table_cleanup().

Fixes: 59c466dd68e7 ("netfilter: nf_flow_table: add a new flow state for tearing down offloading")
Signed-off-by: Taehee Yoo <ap420073@xxxxxxxxx>
---
 include/net/netfilter/nf_flow_table.h |  2 +-
 net/netfilter/nf_flow_table_core.c    | 10 +++++++---
 net/netfilter/nft_flow_offload.c      |  2 +-
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index 0e355f4a3d76..77e2761d4f2f 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -99,7 +99,7 @@ int nf_flow_table_iterate(struct nf_flowtable *flow_table,
 			  void (*iter)(struct flow_offload *flow, void *data),
 			  void *data);
 
-void nf_flow_table_cleanup(struct net *net, struct net_device *dev);
+void nf_flow_table_cleanup(struct net_device *dev);
 
 int nf_flow_table_init(struct nf_flowtable *flow_table);
 void nf_flow_table_free(struct nf_flowtable *flow_table);
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index d8125616edc7..88aae0ae499c 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -478,14 +478,18 @@ EXPORT_SYMBOL_GPL(nf_flow_table_init);
 static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data)
 {
 	struct net_device *dev = data;
+	struct flow_offload_entry *e;
+
+	e = container_of(flow, struct flow_offload_entry, flow);
 
 	if (!dev) {
 		flow_offload_teardown(flow);
 		return;
 	}
 
-	if (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
-	    flow->tuplehash[1].tuple.iifidx == dev->ifindex)
+	if (net_eq(nf_ct_net(e->ct), dev_net(dev)) &&
+	    (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
+	     flow->tuplehash[1].tuple.iifidx == dev->ifindex))
 		flow_offload_dead(flow);
 }
 
@@ -496,7 +500,7 @@ static void nf_flow_table_iterate_cleanup(struct nf_flowtable *flowtable,
 	flush_delayed_work(&flowtable->gc_work);
 }
 
-void nf_flow_table_cleanup(struct net *net, struct net_device *dev)
+void nf_flow_table_cleanup(struct net_device *dev)
 {
 	struct nf_flowtable *flowtable;
 
diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index d6bab8c3cbb0..e82d9a966c45 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -201,7 +201,7 @@ static int flow_offload_netdev_event(struct notifier_block *this,
 	if (event != NETDEV_DOWN)
 		return NOTIFY_DONE;
 
-	nf_flow_table_cleanup(dev_net(dev), dev);
+	nf_flow_table_cleanup(dev);
 
 	return NOTIFY_DONE;
 }
-- 
2.17.1