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>

diff --git a/include/net/l3mdev.h b/include/net/l3mdev.h
index e942372..031c661 100644 (file)
--- 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);
 
@@ -280,6 +299,26 @@ struct sk_buff *l3mdev_ip6_out(struct sock *sk, struct sk_buff *skb)
        return 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)

diff --git a/net/l3mdev/l3mdev.c b/net/l3mdev/l3mdev.c
index f35899d..e71ca5a 100644 (file)
--- a/net/l3mdev/l3mdev.c
+++ b/net/l3mdev/l3mdev.c
@@ -9,6 +9,99 @@
 #include <net/fib_rules.h>
 #include <net/l3mdev.h>
 
+static DEFINE_SPINLOCK(l3mdev_lock);
+
+struct l3mdev_handler {
+       lookup_by_table_id_t dev_lookup;
+};
+
+static struct l3mdev_handler l3mdev_handlers[L3MDEV_TYPE_MAX + 1];
+
+static int l3mdev_check_type(enum l3mdev_type l3type)
+{
+       if (l3type <= L3MDEV_TYPE_UNSPEC || l3type > L3MDEV_TYPE_MAX)
+               return -EINVAL;
+
+       return 0;
+}
+
+int l3mdev_table_lookup_register(enum l3mdev_type l3type,
+                                lookup_by_table_id_t fn)
+{
+       struct l3mdev_handler *hdlr;
+       int res;
+
+       res = l3mdev_check_type(l3type);
+       if (res)
+               return res;
+
+       hdlr = &l3mdev_handlers[l3type];
+
+       spin_lock(&l3mdev_lock);
+
+       if (hdlr->dev_lookup) {
+               res = -EBUSY;
+               goto unlock;
+       }
+
+       hdlr->dev_lookup = fn;
+       res = 0;
+
+unlock:
+       spin_unlock(&l3mdev_lock);
+
+       return res;
+}
+EXPORT_SYMBOL_GPL(l3mdev_table_lookup_register);
+
+void l3mdev_table_lookup_unregister(enum l3mdev_type l3type,
+                                   lookup_by_table_id_t fn)
+{
+       struct l3mdev_handler *hdlr;
+
+       if (l3mdev_check_type(l3type))
+               return;
+
+       hdlr = &l3mdev_handlers[l3type];
+
+       spin_lock(&l3mdev_lock);
+
+       if (hdlr->dev_lookup == fn)
+               hdlr->dev_lookup = NULL;
+
+       spin_unlock(&l3mdev_lock);
+}
+EXPORT_SYMBOL_GPL(l3mdev_table_lookup_unregister);
+
+int l3mdev_ifindex_lookup_by_table_id(enum l3mdev_type l3type,
+                                     struct net *net, u32 table_id)
+{
+       lookup_by_table_id_t lookup;
+       struct l3mdev_handler *hdlr;
+       int ifindex = -EINVAL;
+       int res;
+
+       res = l3mdev_check_type(l3type);
+       if (res)
+               return res;
+
+       hdlr = &l3mdev_handlers[l3type];
+
+       spin_lock(&l3mdev_lock);
+
+       lookup = hdlr->dev_lookup;
+       if (!lookup)
+               goto unlock;
+
+       ifindex = lookup(net, table_id);
+
+unlock:
+       spin_unlock(&l3mdev_lock);
+
+       return ifindex;
+}
+EXPORT_SYMBOL_GPL(l3mdev_ifindex_lookup_by_table_id);
+
 /**
  *     l3mdev_master_ifindex - get index of L3 master device
  *     @dev: targeted interface