Local service plugin stuff... work in progress.

node/Service.hpp

@@ -0,0 +1,125 @@
+/*
+ * ZeroTier One - Global Peer to Peer Ethernet
+ * Copyright (C) 2012-2013  ZeroTier Networks LLC
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * --
+ *
+ * ZeroTier may be used and distributed under the terms of the GPLv3, which
+ * are available at: http://www.gnu.org/licenses/gpl-3.0.html
+ *
+ * If you would like to embed ZeroTier into a commercial application or
+ * redistribute it in a modified binary form, please contact ZeroTier Networks
+ * LLC. Start here: http://www.zerotier.com/
+ */
+
+#ifndef _ZT_SERVICE_HPP
+#define _ZT_SERVICE_HPP
+
+#include <string>
+#include <stdexcept>
+
+#include "Constants.hpp"
+#include "Dictionary.hpp"
+#include "Thread.hpp"
+#include "Mutex.hpp"
+
+/**
+ * Maximum size of a service message in bytes (sanity limit)
+ */
+#define ZT_SERVICE_MAX_MESSAGE_SIZE 131072
+
+namespace ZeroTier {
+
+class RuntimeEnvironment;
+
+#ifndef __WINDOWS__
+/**
+ * A subprocess that communicates with the host via a simple protocol
+ *
+ * This is currently only supported on *nix systems, and is used to implement
+ * special plugins that are used by supernodes and network configuration
+ * master nodes. Users will probably have no use for it.
+ *
+ * The simple binary protocol consists of a bidirectional stream of string-
+ * serialized Dictionaries prefixed by a 32-bit message length. Input
+ * messages are sent to the subprocess via its stdin, and output is read
+ * from its stdout. Messages printed by the subprocess on its stderr are
+ * logged via the standard Logger instance. If the subprocess dies, an
+ * attempt is made to restart it every second.
+ */
+class Service : protected Thread
+{
+public:
+	/**
+	 * Create and launch a new service
+	 *
+	 * @param renv Runtime environment
+	 * @param name Name of service
+	 * @param path Path to service binary
+	 * @param handler Handler function to call when service generates output
+	 * @param arg First argument to service
+	 */
+	Service(const RuntimeEnvironment *renv,const char *name,const char *path,void (*handler)(void *,Service &,const Dictionary &),void *arg);
+
+	virtual ~Service();
+
+	/**
+	 * Send a message to service subprocess
+	 *
+	 * @param msg Message in key/value dictionary form
+	 * @return True if message was sent
+	 */
+	bool send(const Dictionary &msg);
+
+	/**
+	 * @return Name of service
+	 */
+	inline const char *name() const
+		throw()
+	{
+		return _name.c_str();
+	}
+
+	/**
+	 * @return True if subprocess is running
+	 */
+	inline bool running() const
+		throw()
+	{
+		return (_pid > 0);
+	}
+
+protected:
+	virtual void main()
+		throw();
+
+private:
+	const RuntimeEnvironment *_r;
+	std::string _path;
+	std::string _name;
+	void *_arg;
+	void (*_handler)(void *,Service &,const Dictionary &);
+	long _pid;
+	int _childStdin;
+	int _childStdout;
+	int _childStderr;
+	volatile bool _run;
+};
+#endif // __WINDOWS__
+
+} // namespace ZeroTier
+
+#endif