Added incomplete BSD-compatible network stack driver for lwIP

include/libzt.h

@@ -30,6 +30,8 @@
 #include <sys/socket.h>
 #include <poll.h>
 #include <net/if.h>
+#include <stdlib.h>
+#include <stdint.h>
 
 /****************************************************************************/
 /* For SOCK_RAW support, it will initially be modeled after linux's API, so */
@@ -484,6 +486,11 @@ namespace ZeroTier
 int zts_get_pico_socket(int fd, struct pico_socket **s);
 #endif
 
+/*
+ * Whether we can add a new socket or not. Depends on stack in use
+ */
+bool can_provision_new_socket();
+
 /**
  * Returns the number of sockets either already provisioned or waiting to be
  * Some network stacks may have a limit on the number of sockets that they can