Working TCP fastopen for connect-send.

adsbus/send.h

@@ -1,5 +1,6 @@
 #pragma once
 
+struct buf;
 struct packet;
 struct peer;
 
@@ -8,5 +9,6 @@ void send_cleanup(void);
 struct serializer *send_get_serializer(char *);
 void send_new(int, struct serializer *, struct peer *);
 void send_new_wrapper(int, void *, struct peer *);
+void send_hello(struct buf **, void *);
 void send_write(struct packet *);
 void send_print_usage(void);