Converted the length argument of netconn_write (and therefore also api_msg_msg.msg.w.len) from u16_t into int to be able to send a bigger buffer than 64K with one time (mainly used from lwip_send).

src/include/lwip/api.h

@@ -123,7 +123,7 @@ struct netconn {
   struct api_msg_msg *write_msg;
   /** TCP: when data passed to netconn_write doesn't fit into the send buffer,
       this temporarily stores how much is already sent. */
-  u16_t write_offset;
+  int write_offset;
 #if LWIP_TCPIP_CORE_LOCKING
   /** TCP: when data passed to netconn_write doesn't fit into the send buffer,
       this temporarily stores whether to wake up the original application task
@@ -187,7 +187,7 @@ err_t             netconn_sendto  (struct netconn *conn,
 err_t             netconn_send    (struct netconn *conn,
            struct netbuf *buf);
 err_t             netconn_write   (struct netconn *conn,
-           const void *dataptr, u16_t size,
+           const void *dataptr, int size,
            u8_t copy);
 err_t             netconn_close   (struct netconn *conn);
 

src/include/lwip/api_msg.h

@@ -63,7 +63,7 @@ struct api_msg_msg {
     } bc; /* do_bind, do_connect */
     struct {
       const void *dataptr;
-      u16_t len;
+      int len;
       u8_t copy;
     } w; /* do_write */
     struct {