ZeroTierOne/node/Service.hpp

123 lines
3.3 KiB
C++

/*
* ZeroTier One - Global Peer to Peer Ethernet
* Copyright (C) 2011-2014 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"
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
{
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);
~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); }
/**
* Thread main method; do not call elsewhere
*/
void threadMain()
throw();
private:
const RuntimeEnvironment *RR;
Thread _thread;
std::string _path;
std::string _name;
void *_arg;
void (*_handler)(void *,Service &,const Dictionary &);
volatile long _pid;
volatile int _childStdin;
volatile int _childStdout;
volatile int _childStderr;
volatile bool _run;
};
#endif // __WINDOWS__
} // namespace ZeroTier
#endif