ipv6: export several functions

This patch exports some neighbour discovery functions which can be used
by 6lowpan neighbour discovery ops functionality then.

Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <aar@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index a5e2767..3f0f41d 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -53,6 +53,15 @@
 
 #include <net/neighbour.h>
 
+/* Set to 3 to get tracing... */
+#define ND_DEBUG 1
+
+#define ND_PRINTK(val, level, fmt, ...)				\
+do {								\
+	if (val <= ND_DEBUG)					\
+		net_##level##_ratelimited(fmt, ##__VA_ARGS__);	\
+} while (0)
+
 struct ctl_table;
 struct inet6_dev;
 struct net_device;
@@ -115,6 +124,9 @@
 					  u8 *opt, int opt_len,
 					  struct ndisc_options *ndopts);
 
+void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
+			      int data_len, int pad);
+
 #define NDISC_OPS_REDIRECT_DATA_SPACE	2
 
 /*