attempt to support FreeBSD

socket/socket_fastopen.c

@@ -2,10 +2,15 @@
 #ifndef __MINGW32__
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <netinet/in.h>
 #include <netinet/tcp.h>
 #endif
 #include <errno.h>
 
+#if defined(TCP_FASTOPEN) && !defined(SOL_TCP) && defined(IPPROTO_TCP)
+#define SOL_TCP IPPROTO_TCP
+#endif
+
 int socket_fastopen(int s) {
 #if defined(SOL_TCP) && defined(TCP_FASTOPEN)
   return setsockopt(s,SOL_TCP,TCP_FASTOPEN,(int[]){ 5 }, sizeof(int));