On FreeBSD these needs sys/socket.h. But we realized that the net/in.h is not needed now. (TODO: remove #include <netinet/in.h> and #include <arpa/inet.h> also?)
@@ -17,7 +17,6 @@
#include <string.h>
#include <netinet/in.h>
#include <arpa/inet.h>
-#include <net/if.h>
#include "dhcp6/iface_mgr.h"
#include "dhcp6/dhcp6.h"