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/*
* 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/
*/
#include "Constants.hpp"
#ifndef __WINDOWS__
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <time.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/select.h>
#include <sys/wait.h>
#include "Service.hpp"
#include "RuntimeEnvironment.hpp"
#include "Utils.hpp"
#include "Logger.hpp"
namespace ZeroTier {
Service::Service(const RuntimeEnvironment *renv,const char *name,const char *path,void (*handler)(void *,Service &,const Dictionary &),void *arg) :
_r(renv),
_path(path),
_name(name),
_arg(arg),
_handler(handler),
_pid(-1),
_childStdin(0),
_childStdout(0),
_childStderr(0),
_run(true)
{
_thread = Thread::start(this);
}
Service::~Service()
{
_run = false;
long pid = _pid;
if (pid > 0) {
int st = 0;
::kill(pid,SIGTERM);
for(int i=0;i<20;++i) {
if (waitpid(pid,&st,WNOHANG) == pid) {
pid = 0;
break;
}
Thread::sleep(100);
}
if (pid > 0) {
::kill(pid,SIGKILL);
waitpid(pid,&st,0);
}
}
Thread::join(_thread);
}
bool Service::send(const Dictionary &msg)
{
if (_childStdin <= 0)
return false;
std::string mser = msg.toString();
if (mser.length() > ZT_SERVICE_MAX_MESSAGE_SIZE)
return false;
// This can technically block. We'll fix this if it ends up being a
// problem.
uint32_t len = Utils::hton((uint32_t)mser.length());
if (write(_childStdin,&len,4) != 4)
return false;
if ((int)write(_childStdin,mser.data(),mser.length()) != (int)mser.length())
return false;
return true;
}
void Service::threadMain()
throw()
{
char buf[131072];
fd_set readfds,writefds,exceptfds;
struct timeval tv;
std::string stderrBuf;
std::string stdoutBuf;
unsigned int stdoutExpecting = 0;
while (_run) {
if (_pid <= 0) {
LOG("launching service %s...",_name.c_str());
int in[2],out[2],err[2];
pipe(in);
pipe(out);
pipe(err);
long pid = vfork();
if (pid < 0) {
LOG("service %s terminating: could not fork!",_name.c_str());
return;
} else if (pid) {
// Parent
close(in[0]);
close(out[1]);
close(err[1]);
Thread::sleep(500); // give child time to start
_childStdin = in[1];
_childStdout = out[0];
_childStderr = err[0];
fcntl(_childStdout,F_SETFL,O_NONBLOCK);
fcntl(_childStderr,F_SETFL,O_NONBLOCK);
_pid = pid;
} else {
// Child
close(in[1]);
close(out[0]);
close(err[0]);
dup2(in[0],STDIN_FILENO);
dup2(out[1],STDOUT_FILENO);
dup2(err[1],STDERR_FILENO);
execl(_path.c_str(),_path.c_str(),_r->homePath.c_str(),(const char *)0);
exit(-1);
}
} else {
int st = 0;
if (waitpid(_pid,&st,WNOHANG) == _pid) {
if (_childStdin > 0) close(_childStdin);
_childStdin = 0;
if (_childStdout > 0) close(_childStdout);
if (_childStderr > 0) close(_childStderr);
_pid = 0;
if (!_run)
return;
LOG("service %s exited with exit code: %d, delaying 1s to attempt relaunch",_name.c_str(),st);
Thread::sleep(1000); // wait to relaunch
continue;
}
}
// If we've made it here, _pid is running last we checked.
FD_ZERO(&readfds);
FD_ZERO(&writefds);
FD_ZERO(&exceptfds);
FD_SET(_childStdout,&readfds);
FD_SET(_childStderr,&readfds);
tv.tv_sec = 1;
tv.tv_usec = 0;
select(std::max(_childStdout,_childStderr)+1,&readfds,&writefds,&exceptfds,&tv);
if (!_run) {
if (_childStdin > 0) close(_childStdin);
_childStdin = 0;
if (_childStdout > 0) close(_childStdout);
if (_childStderr > 0) close(_childStderr);
return;
}
if ((_childStderr > 0)&&(FD_ISSET(_childStderr,&readfds))) {
int n = (int)read(_childStderr,buf,sizeof(buf));
for(int i=0;i<n;++i) {
if ((buf[i] == '\r')||(buf[i] == '\n')) {
stderrBuf = Utils::trim(stderrBuf);
if (stderrBuf.length())
LOG("service %s: %s",_name.c_str(),stderrBuf.c_str());
stderrBuf = "";
} else stderrBuf.push_back(buf[i]);
}
}
if ((_childStdout > 0)&&(FD_ISSET(_childStdout,&readfds))) {
int n = (int)read(_childStdout,buf,sizeof(buf));
for(int i=0;i<n;++i) {
stdoutBuf.push_back(buf[i]);
if (stdoutExpecting) {
if (stdoutBuf.length() == stdoutExpecting) {
try {
_handler(_arg,*this,Dictionary(stdoutBuf));
} catch ( ... ) {
LOG("unexpected exception handling message from service %s",_name.c_str());
}
stdoutBuf = "";
stdoutExpecting = 0;
}
} else if (stdoutBuf.length() == 4) {
stdoutExpecting = Utils::ntoh(*((const uint32_t *)stdoutBuf.data()));
stdoutBuf = "";
if (stdoutExpecting > ZT_SERVICE_MAX_MESSAGE_SIZE) {
LOG("message size overrun from service %s: %u bytes -- restarting service",_name.c_str(),stdoutExpecting);
stdoutExpecting = 0;
kill(_pid,SIGKILL);
break;
}
}
}
}
}
}
} // namespace ZeroTier
#endif // __WINDOWS__
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