Add FreeBSD support
diff --git a/net.c b/net.c
index db88c6d..da061c8 100644
--- a/net.c
+++ b/net.c
@@ -36,6 +36,9 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <netinet/in.h>
+#ifdef FREEBSD
+#include <netinet/tcp.h>
+#endif
 #include <arpa/inet.h>
 #if defined(LINUX)
 #include <asm/types.h>