[2/4] tst-env-setuid: Use support_capture_subprogram_self_sgid
Commit Message
Use the support_capture_subprogram_self_sgid to spawn an sgid child.
---
elf/tst-env-setuid.c | 197 +++----------------------------------------
1 file changed, 14 insertions(+), 183 deletions(-)
@@ -29,173 +29,12 @@
#include <sys/wait.h>
#include <unistd.h>
+#include <support/check.h>
#include <support/support.h>
#include <support/test-driver.h>
+#include <support/capture_subprocess.h>
static char SETGID_CHILD[] = "setgid-child";
-#define CHILD_STATUS 42
-
-/* Return a GID which is not our current GID, but is present in the
- supplementary group list. */
-static gid_t
-choose_gid (void)
-{
- const int count = 64;
- gid_t groups[count];
- int ret = getgroups (count, groups);
- if (ret < 0)
- {
- printf ("getgroups: %m\n");
- exit (1);
- }
- gid_t current = getgid ();
- for (int i = 0; i < ret; ++i)
- {
- if (groups[i] != current)
- return groups[i];
- }
- return 0;
-}
-
-/* Spawn and execute a program and verify that it returns the CHILD_STATUS. */
-static pid_t
-do_execve (char **args)
-{
- pid_t kid = vfork ();
-
- if (kid < 0)
- {
- printf ("vfork: %m\n");
- return -1;
- }
-
- if (kid == 0)
- {
- /* Child process. */
- execve (args[0], args, environ);
- _exit (-errno);
- }
-
- if (kid < 0)
- return 1;
-
- int status;
-
- if (waitpid (kid, &status, 0) < 0)
- {
- printf ("waitpid: %m\n");
- return 1;
- }
-
- if (WEXITSTATUS (status) == EXIT_UNSUPPORTED)
- return EXIT_UNSUPPORTED;
-
- if (!WIFEXITED (status) || WEXITSTATUS (status) != CHILD_STATUS)
- {
- printf ("Unexpected exit status %d from child process\n",
- WEXITSTATUS (status));
- return 1;
- }
- return 0;
-}
-
-/* Copies the executable into a restricted directory, so that we can
- safely make it SGID with the TARGET group ID. Then runs the
- executable. */
-static int
-run_executable_sgid (gid_t target)
-{
- char *dirname = xasprintf ("%s/tst-tunables-setuid.%jd",
- test_dir, (intmax_t) getpid ());
- char *execname = xasprintf ("%s/bin", dirname);
- int infd = -1;
- int outfd = -1;
- int ret = 0;
- if (mkdir (dirname, 0700) < 0)
- {
- printf ("mkdir: %m\n");
- goto err;
- }
- infd = open ("/proc/self/exe", O_RDONLY);
- if (infd < 0)
- {
- printf ("open (/proc/self/exe): %m\n");
- goto err;
- }
- outfd = open (execname, O_WRONLY | O_CREAT | O_EXCL, 0700);
- if (outfd < 0)
- {
- printf ("open (%s): %m\n", execname);
- goto err;
- }
- char buf[4096];
- for (;;)
- {
- ssize_t rdcount = read (infd, buf, sizeof (buf));
- if (rdcount < 0)
- {
- printf ("read: %m\n");
- goto err;
- }
- if (rdcount == 0)
- break;
- char *p = buf;
- char *end = buf + rdcount;
- while (p != end)
- {
- ssize_t wrcount = write (outfd, buf, end - p);
- if (wrcount == 0)
- errno = ENOSPC;
- if (wrcount <= 0)
- {
- printf ("write: %m\n");
- goto err;
- }
- p += wrcount;
- }
- }
- if (fchown (outfd, getuid (), target) < 0)
- {
- printf ("fchown (%s): %m\n", execname);
- goto err;
- }
- if (fchmod (outfd, 02750) < 0)
- {
- printf ("fchmod (%s): %m\n", execname);
- goto err;
- }
- if (close (outfd) < 0)
- {
- printf ("close (outfd): %m\n");
- goto err;
- }
- if (close (infd) < 0)
- {
- printf ("close (infd): %m\n");
- goto err;
- }
-
- char *args[] = {execname, SETGID_CHILD, NULL};
-
- ret = do_execve (args);
-
-err:
- if (outfd >= 0)
- close (outfd);
- if (infd >= 0)
- close (infd);
- if (execname)
- {
- unlink (execname);
- free (execname);
- }
- if (dirname)
- {
- rmdir (dirname);
- free (dirname);
- }
- return ret;
-}
#ifndef test_child
static int
@@ -256,40 +95,32 @@ do_test (int argc, char **argv)
if (argc == 2 && strcmp (argv[1], SETGID_CHILD) == 0)
{
if (getgid () == getegid ())
- {
- /* This can happen if the file system is mounted nosuid. */
- fprintf (stderr, "SGID failed: GID and EGID match (%jd)\n",
- (intmax_t) getgid ());
- exit (EXIT_UNSUPPORTED);
- }
+ /* This can happen if the file system is mounted nosuid. */
+ FAIL_UNSUPPORTED ("SGID failed: GID and EGID match (%jd)\n",
+ (intmax_t) getgid ());
int ret = test_child ();
if (ret != 0)
exit (1);
- exit (CHILD_STATUS);
+ exit (EXIT_SUCCESS);
}
else
{
if (test_parent () != 0)
exit (1);
- /* Try running a setgid program. */
- gid_t target = choose_gid ();
- if (target == 0)
- {
- fprintf (stderr,
- "Could not find a suitable GID for user %jd, skipping test\n",
- (intmax_t) getuid ());
- exit (0);
- }
+ int status = support_capture_subprogram_self_sgid (SETGID_CHILD);
- return run_executable_sgid (target);
- }
+ if (WEXITSTATUS (status) == EXIT_UNSUPPORTED)
+ return EXIT_UNSUPPORTED;
+
+ if (!WIFEXITED (status))
+ FAIL_EXIT1 ("Unexpected exit status %d from child process\n", status);
- /* Something went wrong and our argv was corrupted. */
- _exit (1);
+ return 0;
+ }
}
#define TEST_FUNCTION_ARGV do_test