net/ip_tunnels: Introduce tunnel_id_to_key32() and key32_to_tunnel_id()

Add utility functions to convert a 32 bits key into a 64 bits tunnel and
vice versa.
These functions will be used instead of cloning code in GRE and VXLAN,
and in tc act_iptunnel which will be introduced in a following patch in
this patchset.

Signed-off-by: Amir Vadai <amir@vadai.me>
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index a5e7035fb93f..e598c639aa6f 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -222,6 +222,25 @@ static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
         return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
 }
 
+static inline __be64 key32_to_tunnel_id(__be32 key)
+{
+#ifdef __BIG_ENDIAN
+        return (__force __be64)key;
+#else
+        return (__force __be64)((__force u64)key << 32);
+#endif
+}
+
+/* Returns the least-significant 32 bits of a __be64. */
+static inline __be32 tunnel_id_to_key32(__be64 tun_id)
+{
+#ifdef __BIG_ENDIAN
+        return (__force __be32)tun_id;
+#else
+        return (__force __be32)((__force u64)tun_id >> 32);
+#endif
+}
+
 #ifdef CONFIG_INET
 
 int ip_tunnel_init(struct net_device *dev);