111 lines
2.3 KiB
C
111 lines
2.3 KiB
C
/*
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* Copyright 2008-2013 Various Authors
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* Copyright 2005 Timo Hirvonen
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "spawn.h"
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#include "file.h"
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <errno.h>
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int spawn(char *argv[], int *status, int do_wait)
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{
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pid_t pid;
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int err_pipe[2];
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if (pipe(err_pipe) == -1)
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return -1;
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pid = fork();
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if (pid == -1) {
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/* error */
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return -1;
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} else if (pid == 0) {
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/* child */
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int dev_null, err, i;
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/* create grandchild and exit child to avoid zombie processes */
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if (!do_wait) {
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switch (fork()) {
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case 0:
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/* grandchild */
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break;
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case -1:
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/* error */
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_exit(127);
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default:
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/* parent of grandchild */
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_exit(0);
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}
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}
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close(err_pipe[0]);
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fcntl(err_pipe[1], F_SETFD, FD_CLOEXEC);
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/* redirect stdout and stderr to /dev/null if possible */
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dev_null = open("/dev/null", O_WRONLY);
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if (dev_null != -1) {
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dup2(dev_null, 1);
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dup2(dev_null, 2);
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}
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/* not interactive, close stdin */
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close(0);
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/* close unused fds */
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for (i = 3; i < 30; i++)
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close(i);
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execvp(argv[0], argv);
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/* error */
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err = errno;
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write_all(err_pipe[1], &err, sizeof(int));
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exit(1);
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} else {
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/* parent */
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int rc, errno_save, child_errno, tmp;
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close(err_pipe[1]);
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rc = read_all(err_pipe[0], &child_errno, sizeof(int));
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errno_save = errno;
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close(err_pipe[0]);
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if (!do_wait)
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status = &tmp;
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waitpid(pid, status, 0);
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if (rc == -1) {
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errno = errno_save;
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return -1;
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}
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if (rc == sizeof(int)) {
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errno = child_errno;
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return -1;
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}
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if (rc != 0) {
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errno = EMSGSIZE;
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return -1;
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}
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return 0;
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}
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}
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