[NETLINK]: fib_lookup() via netlink

Below is a more generic patch to do fib_lookup via netlink. For others 
we should say that we discussed this as a way to verify route selection.
It's also possible there are others uses for this.

In short the fist half of struct fib_result_nl is filled in by caller 
and netlink call fills in the other half and returns it.

In case anyone is interested there is a corresponding user app to compare 
the full routing table this was used to test implementation of the LC-trie. 

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index e38407a23d04..561d4dc75836 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -14,6 +14,7 @@
 #define NETLINK_SELINUX         7       /* SELinux event notifications */
 #define NETLINK_ARPD            8
 #define NETLINK_AUDIT           9       /* auditing */
+#define NETLINK_FIB_LOOKUP      10      
 #define NETLINK_ROUTE6          11      /* af_inet6 route comm channel */
 #define NETLINK_IP6_FW          13
 #define NETLINK_DNRTMSG         14      /* DECnet routing messages */
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index e5a5f6b62f88..a4208a336ac0 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -109,6 +109,20 @@ struct fib_result {
 #endif
 };
 
+struct fib_result_nl {
+        u32             fl_addr;   /* To be looked up*/ 
+        u32             fl_fwmark; 
+        unsigned char   fl_tos;
+        unsigned char   fl_scope;
+        unsigned char   tb_id_in;
+
+        unsigned char   tb_id;      /* Results */
+        unsigned char   prefixlen;
+        unsigned char   nh_sel;
+        unsigned char   type;
+        unsigned char   scope;
+        int             err;      
+};
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH