mavlink: add a shell using SERIAL_CONTROL MAVLink message

src/modules/mavlink/mavlink_shell.h

@@ -0,0 +1,93 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2016 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file mavlink_shell.h
+ * A shell to be used via MAVLink
+ *
+ * @author Beat Küng <beat-kueng@gmx.net>
+ */
+
+
+#include <stddef.h>
+#include <stdint.h>
+#include <px4_tasks.h>
+
+#pragma once
+
+class MavlinkShell
+{
+public:
+	MavlinkShell();
+
+	~MavlinkShell();
+
+	/**
+	 * Start the mavlink shell.
+	 *
+	 * @return		0 on success.
+	 */
+	int		start();
+
+
+	/**
+	 * Write to the shell
+	 * @return number of written bytes
+	 */
+	size_t write(uint8_t* buffer, size_t len);
+
+	/**
+	 * Read from the shell. This is blocking, if 0 bytes are available, this will block.
+	 * @param len buffer length
+	 * @return number of bytes read.
+	 */
+	size_t read(uint8_t* buffer, size_t len);
+
+	/**
+	 * Get the number of bytes that can be read.
+	 */
+	size_t available();
+
+private:
+
+	int _to_shell_fd = -1; /** fd to write to the shell */
+	int _from_shell_fd = -1; /** fd to read from the shell */
+	int _shell_fds[2] = {-1, -1}; /** stdin & out used by the shell */
+	px4_task_t _task;
+
+	static int shell_start_thread(int argc, char *argv[]);
+
+	/* do not allow copying this class */
+	MavlinkShell(const MavlinkShell &) = delete;
+	MavlinkShell operator=(const MavlinkShell &) = delete;
+};