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/*
* barrier -- mouse and keyboard sharing utility
* Copyright (C) 2012-2016 Symless Ltd.
* Copyright (C) 2002 Chris Schoeneman
*
* This package is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* found in the file LICENSE that should have accompanied this file.
*
* This package 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/>.
*/
#include "arch/unix/ArchDaemonUnix.h"
#include "arch/unix/XArchUnix.h"
#include "base/Log.h"
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <cstdlib>
//
// ArchDaemonUnix
//
ArchDaemonUnix::ArchDaemonUnix()
{
// do nothing
}
ArchDaemonUnix::~ArchDaemonUnix()
{
// do nothing
}
#ifdef __APPLE__
// In Mac OS X, fork()'d child processes can't use most APIs (the frameworks
// that Barrier uses in fact prevent it and make the process just up and die),
// so need to exec a copy of the program that doesn't fork so isn't limited.
int
execSelfNonDaemonized()
{
extern char** NXArgv;
char** selfArgv = NXArgv;
setenv("_BARRIER_DAEMONIZED", "", 1);
execvp(selfArgv[0], selfArgv);
return 0;
}
bool alreadyDaemonized() {
return getenv("_BARRIER_DAEMONIZED") != NULL;
}
#endif
int
ArchDaemonUnix::daemonize(const char* name, DaemonFunc func)
{
#ifdef __APPLE__
if (alreadyDaemonized())
return func(1, &name);
#endif
// fork so shell thinks we're done and so we're not a process
// group leader
switch (fork()) {
case -1:
// failed
throw XArchDaemonFailed(new XArchEvalUnix(errno));
case 0:
// child
break;
default:
// parent exits
exit(0);
}
// become leader of a new session
setsid();
#ifndef __APPLE__
// NB: don't run chdir on apple; causes strange behaviour.
// chdir to root so we don't keep mounted filesystems points busy
// TODO: this is a bit of a hack - can we find a better solution?
int chdirErr = chdir("/");
if (chdirErr)
// NB: file logging actually isn't working at this point!
LOG((CLOG_ERR "chdir error: %i", chdirErr));
#endif
// mask off permissions for any but owner
umask(077);
// close open files. we only expect stdin, stdout, stderr to be open.
close(0);
close(1);
close(2);
// attach file descriptors 0, 1, 2 to /dev/null so inadvertent use
// of standard I/O safely goes in the bit bucket.
open("/dev/null", O_RDONLY);
open("/dev/null", O_RDWR);
int dupErr = dup(1);
if (dupErr < 0) {
// NB: file logging actually isn't working at this point!
LOG((CLOG_ERR "dup error: %i", dupErr));
}
#ifdef __APPLE__
return execSelfNonDaemonized();
#endif
// invoke function
return func(1, &name);
}
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