neigh: Factor out ___neigh_lookup_noref

While looking at the mpls code I found myself writing yet another
version of neigh_lookup_noref.  We currently have __ipv4_lookup_noref
and __ipv6_lookup_noref.

So to make my work a little easier and to make it a smidge easier to
verify/maintain the mpls code in the future I stopped and wrote
___neigh_lookup_noref.  Then I rewote __ipv4_lookup_noref and
__ipv6_lookup_noref in terms of this new function.  I tested my new
version by verifying that the same code is generated in
ip_finish_output2 and ip6_finish_output2 where these functions are
inlined.

To get to ___neigh_lookup_noref I added a new neighbour cache table
function key_eq.  So that the static size of the key would be
available.

I also added __neigh_lookup_noref for people who want to to lookup
a neighbour table entry quickly but don't know which neibhgour table
they are going to look up.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 0 deletions

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index e363bbc2420d..247ad7c298f7 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -84,6 +84,7 @@ do {								\
 static u32 ndisc_hash(const void *pkey,
                       const struct net_device *dev,
                       __u32 *hash_rnd);
+static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
 static int ndisc_constructor(struct neighbour *neigh);
 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
@@ -119,6 +120,7 @@ struct neigh_table nd_tbl = {
         .key_len =      sizeof(struct in6_addr),
         .protocol =     cpu_to_be16(ETH_P_IPV6),
         .hash =         ndisc_hash,
+        .key_eq =       ndisc_key_eq,
         .constructor =  ndisc_constructor,
         .pconstructor = pndisc_constructor,
         .pdestructor =  pndisc_destructor,
@@ -295,6 +297,11 @@ static u32 ndisc_hash(const void *pkey,
         return ndisc_hashfn(pkey, dev, hash_rnd);
 }
 
+static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
+{
+        return neigh_key_eq128(n, pkey);
+}
+
 static int ndisc_constructor(struct neighbour *neigh)
 {
         struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;