treewide: Add include guards

...at the moment, just for consistency with packet.h, icmp.h,
tcp.h and udp.h.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/ndp.h b/ndp.h
index a26673e..7280b23 100644
--- a/ndp.h
+++ b/ndp.h
@@ -3,5 +3,10 @@
  * Author: Stefano Brivio <sbrivio@redhat.com>
  */
 
+#ifndef NDP_H
+#define NDP_H
+
 int ndp(struct ctx *c, struct icmp6hdr *ih, unsigned char *eh_source,
 	struct in6_addr *saddr);
+
+#endif /* NDP_H */