ax25: Refactor to use private neighbour operations.

AX25 already has it's own private arp cache operations to isolate
it's abuse of dev_rebuild_header to transmit packets.  Add a function
ax25_neigh_construct that will allow all of the ax25 devices to
force using these operations, so that the generic arp code does
not need to.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ax25/ax25_ip.c b/net/ax25/ax25_ip.c
index d93103b..bff12e0 100644
--- a/net/ax25/ax25_ip.c
+++ b/net/ax25/ax25_ip.c
@@ -216,6 +216,22 @@
 	return 1;
 }
 
+int ax25_neigh_construct(struct neighbour *neigh)
+{
+	/* This trouble could be saved if ax25 would right a proper
+	 * dev_queue_xmit function.
+	 */
+	struct ax25_neigh_priv *priv = neighbour_priv(neigh);
+
+	if (neigh->tbl->family != AF_INET)
+		return -EINVAL;
+
+	priv->ops = *neigh->ops;
+	priv->ops.output = neigh_compat_output;
+	priv->ops.connected_output = neigh_compat_output;
+	return 0;
+}
+
 #else	/* INET */
 
 static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
@@ -230,6 +246,10 @@
 	return 1;
 }
 
+int ax25_neigh_construct(struct neighbour *neigh)
+{
+	return 0;
+}
 #endif
 
 const struct header_ops ax25_header_ops = {
@@ -238,4 +258,5 @@
 };
 
 EXPORT_SYMBOL(ax25_header_ops);
+EXPORT_SYMBOL(ax25_neigh_construct);