l3mdev: add infrastructure for table to VRF mapping

Add infrastructure to l3mdev (the core code for Layer 3 master devices) in
order to find out the corresponding VRF device for a given table id.
Therefore, the l3mdev implementations:
 - can register a callback that returns the device index of the l3mdev
   associated with a given table id;
 - can offer the lookup function (table to VRF device).

Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 39 insertions, 0 deletions

diff --git a/include/net/l3mdev.h b/include/net/l3mdev.h
index e942372b077b..031c661aa14d 100644
--- a/include/net/l3mdev.h
+++ b/include/net/l3mdev.h
@@ -10,6 +10,16 @@
 #include <net/dst.h>
 #include <net/fib_rules.h>
 
+enum l3mdev_type {
+	L3MDEV_TYPE_UNSPEC,
+	L3MDEV_TYPE_VRF,
+	__L3MDEV_TYPE_MAX
+};
+
+#define L3MDEV_TYPE_MAX (__L3MDEV_TYPE_MAX - 1)
+
+typedef int (*lookup_by_table_id_t)(struct net *net, u32 table_d);
+
 /**
  * struct l3mdev_ops - l3mdev operations
  *
@@ -37,6 +47,15 @@ struct l3mdev_ops {
 
 #ifdef CONFIG_NET_L3_MASTER_DEV
 
+int l3mdev_table_lookup_register(enum l3mdev_type l3type,
+				 lookup_by_table_id_t fn);
+
+void l3mdev_table_lookup_unregister(enum l3mdev_type l3type,
+				    lookup_by_table_id_t fn);
+
+int l3mdev_ifindex_lookup_by_table_id(enum l3mdev_type l3type, struct net *net,
+				      u32 table_id);
+
 int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
 			  struct fib_lookup_arg *arg);
 
@@ -281,6 +300,26 @@ struct sk_buff *l3mdev_ip6_out(struct sock *sk, struct sk_buff *skb)
 }
 
 static inline
+int l3mdev_table_lookup_register(enum l3mdev_type l3type,
+				 lookup_by_table_id_t fn)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline
+void l3mdev_table_lookup_unregister(enum l3mdev_type l3type,
+				    lookup_by_table_id_t fn)
+{
+}
+
+static inline
+int l3mdev_ifindex_lookup_by_table_id(enum l3mdev_type l3type, struct net *net,
+				      u32 table_id)
+{
+	return -ENODEV;
+}
+
+static inline
 int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
 			  struct fib_lookup_arg *arg)
 {