Implement ssh_blocking_flush()

Based on code from Jan Willamowius

include/libssh/libssh.h

@@ -324,6 +324,7 @@ enum ssh_scp_request_types {
   SSH_SCP_REQUEST_WARNING
 };
 
+LIBSSH_API int ssh_blocking_flush(ssh_session session, int timeout);
 LIBSSH_API ssh_channel ssh_channel_accept_x11(ssh_channel channel, int timeout_ms);
 LIBSSH_API int ssh_channel_change_pty_size(ssh_channel channel,int cols,int rows);
 LIBSSH_API int ssh_channel_close(ssh_channel channel);

include/libssh/socket.h

@@ -53,6 +53,7 @@ void ssh_socket_set_write_wontblock(ssh_socket s);
 void ssh_socket_set_read_wontblock(ssh_socket s);
 void ssh_socket_set_except(ssh_socket s);
 int ssh_socket_get_status(ssh_socket s);
+int ssh_socket_buffered_write_bytes(ssh_socket s);
 int ssh_socket_data_available(ssh_socket s);
 int ssh_socket_data_writable(ssh_socket s);
 

src/session.c

@@ -297,6 +297,31 @@ int ssh_is_blocking(ssh_session session){
 	return (session->flags&SSH_SESSION_FLAG_BLOCKING) ? 1 : 0;
 }
 
+/**
+ * @brief Blocking flush of the outgoing buffer
+ * @param[in] session The SSH session
+ * @param[in] timeout Set an upper limit on the time for which this function
+ *                    will block, in milliseconds. Specifying a negative value
+ *                    means an infinite timeout. This parameter is passed to
+ *                    the poll() function.
+ * @returns           SSH_OK on success, SSH_ERROR otherwise.
+ */
+
+int ssh_blocking_flush(ssh_session session, int timeout){
+	ssh_socket s;
+	if(session==NULL)
+		return SSH_ERROR;
+
+	enter_function();
+	s=session->socket;
+	while (ssh_socket_buffered_write_bytes(s) > 0 && session->alive) {
+		ssh_handle_packets(session, timeout);
+	}
+
+	leave_function();
+	return SSH_OK;
+}
+
 /**
  * @brief Check if we are connected.
  *

src/socket.c

@@ -644,6 +644,18 @@ int ssh_socket_data_writable(ssh_socket s) {
   return s->write_wontblock;
 }
 
+/** @internal
+ * @brief returns the number of outgoing bytes currently buffered
+ * @param s the socket
+ * @returns numbers of bytes buffered, or 0 if the socket isn't connected
+ */
+int ssh_socket_buffered_write_bytes(ssh_socket s){
+	if(s==NULL || s->out_buffer == NULL)
+		return 0;
+	return buffer_get_rest_len(s->out_buffer);
+}
+
+
 int ssh_socket_get_status(ssh_socket s) {
   int r = 0;