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/* Check posix_spawn add file actions.
Copyright (C) 2016-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library 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.
The GNU C Library 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 the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <stdio.h>
#include <spawn.h>
#include <error.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/resource.h>
static int do_test (void);
#define TEST_FUNCTION do_test ()
#include <test-skeleton.c>
static int
do_test (void)
{
/* The test checks if posix_spawn open file action close the file descriptor
before opening a new one in case the input file descriptor is already
opened. It does by exhausting all file descriptors on the process before
issue posix_spawn. It then issues a posix_spawn for '/bin/sh echo $$'
and add two rules:
1. Redirect stdout to a temporary filepath
2. Redirect stderr to stdout
If the implementation does not close the file 1. will fail with
EMFILE. */
struct rlimit rl;
int max_fd = 24;
/* Set maximum number of file descriptor to a low value to avoid open
too many files in environments where RLIMIT_NOFILE is large and to
limit the array size to track the opened file descriptors. */
if (getrlimit (RLIMIT_NOFILE, &rl) == -1)
{
printf ("error: getrlimit RLIMIT_NOFILE failed");
exit (EXIT_FAILURE);
}
max_fd = (rl.rlim_cur < max_fd ? rl.rlim_cur : max_fd);
rl.rlim_cur = max_fd;
if (setrlimit (RLIMIT_NOFILE, &rl) == 1)
{
printf ("error: setrlimit RLIMIT_NOFILE to %u failed", max_fd);
exit (EXIT_FAILURE);
}
/* Exhauste the file descriptor limit with temporary files. */
int files[max_fd];
int nfiles = 0;
for (;;)
{
int fd = create_temp_file ("tst-spawn3.", NULL);
if (fd == -1)
{
if (errno != EMFILE)
{
printf ("error: create_temp_file returned -1 with "
"errno != EMFILE\n");
exit (EXIT_FAILURE);
}
break;
}
files[nfiles++] = fd;
}
posix_spawn_file_actions_t a;
if (posix_spawn_file_actions_init (&a) != 0)
{
puts ("error: spawn_file_actions_init failed");
exit (EXIT_FAILURE);
}
/* Executes a /bin/sh echo $$ 2>&1 > /tmp/tst-spawn3.pid . */
const char pidfile[] = "/tmp/tst-spawn3.pid";
if (posix_spawn_file_actions_addopen (&a, STDOUT_FILENO, pidfile, O_WRONLY |
O_CREAT | O_TRUNC, 0644) != 0)
{
puts ("error: spawn_file_actions_addopen failed");
exit (EXIT_FAILURE);
}
if (posix_spawn_file_actions_adddup2 (&a, STDOUT_FILENO, STDERR_FILENO) != 0)
{
puts ("error: spawn_file_actions_addclose");
exit (EXIT_FAILURE);
}
/* Since execve (called by posix_spawn) might require to open files to
actually execute the shell script, setup to close the temporary file
descriptors. */
for (int i=0; i<nfiles; i++)
{
if (posix_spawn_file_actions_addclose (&a, files[i]))
{
printf ("error: posix_spawn_file_actions_addclose failed");
exit (EXIT_FAILURE);
}
}
char *spawn_argv[] = { (char *) _PATH_BSHELL, (char *) "-c",
(char *) "echo $$", NULL };
pid_t pid;
if (posix_spawn (&pid, _PATH_BSHELL, &a, NULL, spawn_argv, NULL) != 0)
{
puts ("error: posix_spawn failed");
exit (EXIT_FAILURE);
}
int status;
int err = waitpid (pid, &status, 0);
if (err != pid)
{
puts ("error: waitpid failed");
exit (EXIT_FAILURE);
}
/* Close the temporary files descriptor so it can check posix_spawn
output. */
for (int i=0; i<nfiles; i++)
{
if (close (files[i]))
{
printf ("error: close failed\n");
exit (EXIT_FAILURE);
}
}
int pidfd = open (pidfile, O_RDONLY);
if (pidfd == -1)
{
printf ("error: open pidfile failed\n");
exit (EXIT_FAILURE);
}
char buf[64];
ssize_t n;
if ((n = read (pidfd, buf, sizeof (buf))) < 0)
{
printf ("error: read pidfile failed\n");
exit (EXIT_FAILURE);
}
unlink (pidfile);
/* We only expect to read the PID. */
char *endp;
long int rpid = strtol (buf, &endp, 10);
if (*endp != '\n')
{
printf ("error: didn't parse whole line: \"%s\"\n", buf);
exit (EXIT_FAILURE);
}
if (endp == buf)
{
puts ("error: read empty line");
exit (EXIT_FAILURE);
}
if (rpid != pid)
{
printf ("error: found \"%s\", expected PID %ld\n", buf, (long int) pid);
exit (EXIT_FAILURE);
}
return 0;
}
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