ip_tunnel: replace dst_cache with generic implementation

The current ip_tunnel cache implementation is prone to a race
that will cause the wrong dst to be cached on cuncurrent dst cache
miss and ip tunnel update via netlink.

Replacing with the generic implementation fix the issue.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Suggested-and-acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 7 deletions

diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index bc439f32baa9..fd36936d85a6 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -13,6 +13,7 @@
 #include <net/netns/generic.h>
 #include <net/rtnetlink.h>
 #include <net/lwtunnel.h>
+#include <net/dst_cache.h>
 
 #if IS_ENABLED(CONFIG_IPV6)
 #include <net/ipv6.h>
@@ -85,11 +86,6 @@ struct ip_tunnel_prl_entry {
         struct rcu_head                 rcu_head;
 };
 
-struct ip_tunnel_dst {
-        struct dst_entry __rcu          *dst;
-        __be32                           saddr;
-};
-
 struct metadata_dst;
 
 struct ip_tunnel {
@@ -108,7 +104,7 @@ struct ip_tunnel {
         int             tun_hlen;       /* Precalculated header length */
         int             mlink;
 
-        struct ip_tunnel_dst __percpu *dst_cache;
+        struct dst_cache dst_cache;
 
         struct ip_tunnel_parm parms;
 
@@ -247,7 +243,6 @@ int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
                       struct ip_tunnel_parm *p);
 void ip_tunnel_setup(struct net_device *dev, int net_id);
-void ip_tunnel_dst_reset_all(struct ip_tunnel *t);
 int ip_tunnel_encap_setup(struct ip_tunnel *t,
                           struct ip_tunnel_encap *ipencap);