TCP Fast Open CONNECT_IN_PROGRESS

src/tunnel.c

@@ -473,10 +473,32 @@ remote_send_cb(EV_P_ ev_io *w, int revents)
         // has data to send
         ssize_t s = -1;
         if (remote->addr != NULL) {
+            
+#ifdef MSG_FASTOPEN
             s = sendto(remote->fd, remote->buf->data + remote->buf->idx,
-                               remote->buf->len, MSG_FASTOPEN, remote->addr,                          
-                               get_sockaddr_len(remote->addr));
+                       remote->buf->len, MSG_FASTOPEN, remote->addr,                          
+                       get_sockaddr_len(remote->addr));
+#endif
+            
             remote->addr = NULL;
+            
+            if (s == -1) {
+                if (errno == CONNECT_IN_PROGRESS) {
+                    ev_io_start(EV_A_ & remote_send_ctx->io);
+                    ev_timer_start(EV_A_ & remote_send_ctx->watcher);
+                } else {
+                    if (errno == EOPNOTSUPP || errno == EPROTONOSUPPORT ||
+                            errno == ENOPROTOOPT) {
+                        fast_open = 0;
+                        LOGE("fast open is not supported on this platform");
+                    } else {
+                        ERROR("fast_open_connect");
+                    }
+                    close_and_free_remote(EV_A_ remote);
+                    close_and_free_server(EV_A_ server);
+                }
+                return;
+            }
         } else {
             s = send(remote->fd, remote->buf->data + remote->buf->idx,
                 remote->buf->len, 0);