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/***
This file is part of PulseAudio.
Copyright 2007 Lennart Poettering
PulseAudio is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
PulseAudio 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
***/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <errno.h>
#include <stdio.h>
#include <sys/types.h>
#include <dirent.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#ifdef HAVE_SYS_PRCTL_H
#include <sys/prctl.h>
#endif
#ifdef HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif
#include <pulsecore/core-util.h>
#include <pulsecore/core-error.h>
#include <pulsecore/pipe.h>
#include "start-child.h"
int pa_start_child_for_read(const char *name, const char *argv1, pid_t *pid) {
#ifdef HAVE_FORK
pid_t child;
int pipe_fds[2] = { -1, -1 };
if (pipe(pipe_fds) < 0) {
pa_log("pipe() failed: %s", pa_cstrerror(errno));
goto fail;
}
if ((child = fork()) == (pid_t) -1) {
pa_log("fork() failed: %s", pa_cstrerror(errno));
goto fail;
} else if (child != 0) {
/* Parent */
pa_assert_se(pa_close(pipe_fds[1]) == 0);
if (pid)
*pid = child;
return pipe_fds[0];
} else {
/* child */
pa_reset_personality();
pa_assert_se(pa_close(pipe_fds[0]) == 0);
pa_assert_se(dup2(pipe_fds[1], STDOUT_FILENO) == STDOUT_FILENO);
if (pipe_fds[1] != STDOUT_FILENO)
pa_assert_se(pa_close(pipe_fds[1]) == 0);
pa_close(STDIN_FILENO);
pa_assert_se(open("/dev/null", O_RDONLY) == STDIN_FILENO);
pa_close(STDERR_FILENO);
pa_assert_se(open("/dev/null", O_WRONLY) == STDERR_FILENO);
pa_close_all(-1);
pa_reset_sigs(-1);
pa_unblock_sigs(-1);
pa_reset_priority();
pa_unset_env_recorded();
/* Make sure our children are not influenced by the
* LD_BIND_NOW we set for ourselves. */
pa_unset_env("LD_BIND_NOW");
#ifdef PR_SET_PDEATHSIG
/* On Linux we can use PR_SET_PDEATHSIG to have the helper
process killed when the daemon dies abnormally. On non-Linux
machines the client will die as soon as it writes data to
stdout again (SIGPIPE) */
prctl(PR_SET_PDEATHSIG, SIGTERM, 0, 0, 0);
#endif
execl(name, name, argv1, NULL);
_exit(1);
}
fail:
pa_close_pipe(pipe_fds);
#endif /* HAVE_FORK */
return -1;
}
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