testcases/kernel/syscalls/ipc/shmctl/shmctl03.c

/*
 *
 *   Copyright (c) International Business Machines  Corp., 2001
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program 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, write to the Free Software
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/*
 * NAME
 *	shmctl03.c
 *
 * DESCRIPTION
 *	shmctl03 - check for EACCES, and EPERM errors
 *
 * ALGORITHM
 *	create a shared memory segment with root only read & write permissions
 *	fork a child process
 *	if child
 *	  set the ID of the child process to that of "ltpuser1"
 *	  call do_child()
 *	  loop if that option was specified
 *	    call shmctl() using three different invalid cases
 *	    check the errno value
 *	      issue a PASS message if we get EACCES or EPERM
 *	    otherwise, the tests fails
 *	      issue a FAIL message
 *	  call cleanup
 *	if parent
 *	  wait for child to exit
 *	  remove the shared memory segment
 *
 * USAGE:  <for command-line>
 *  shmctl03 [-c n] [-e] [-i n] [-I x] [-P x] [-t]
 *     where,  -c n : Run n copies concurrently.
 *             -e   : Turn on errno logging.
 *	       -i n : Execute test n times.
 *	       -I x : Execute test for x seconds.
 *	       -P x : Pause for x seconds between iterations.
 *	       -t   : Turn on syscall timing.
 *
 * HISTORY
 *	03/2001 - Written by Wayne Boyer
 *
 * RESTRICTIONS
 *	test must be run as root
 */

#include "ipcshm.h"
#include <sys/types.h>
#include <sys/wait.h>
#include "safe_macros.h"

char *TCID = "shmctl03";
int shm_id_1 = -1;

uid_t ltp_uid;
char *ltp_user = "nobody";

struct shmid_ds buf;

struct test_case_t {
	int *shmid;
	int cmd;
	struct shmid_ds *sbuf;
	int error;
} TC[] = {
	/* EACCES - child has no read permission for segment */
	{
	&shm_id_1, IPC_STAT, &buf, EACCES},
	    /* EPERM - IPC_SET - child doesn't have permission to change segment */
	{
	&shm_id_1, IPC_SET, &buf, EPERM},
	    /* EPERM - IPC_RMID - child can not remove the segment */
	{
&shm_id_1, IPC_RMID, &buf, EPERM},};

int TST_TOTAL = ARRAY_SIZE(TC);

int main(int ac, char **av)
{
	int pid;
	void do_child(void);

	tst_parse_opts(ac, av, NULL, NULL);

	setup();		/* global setup */

	if ((pid = FORK_OR_VFORK()) == -1) {
		tst_brkm(TBROK, cleanup, "could not fork");
	}

	if (pid == 0) {		/* child */
		/* set  the user ID of the child to the non root user */
		if (setuid(ltp_uid) == -1) {
			tst_resm(TBROK, "setuid() failed");
			exit(1);
		}

		do_child();
	} else {
		/* wait for the child to return */
		SAFE_WAITPID(cleanup, pid, NULL, 0);

		/* if it exists, remove the shared memory resource */
		rm_shm(shm_id_1);

		tst_rmdir();
	}

	cleanup();
	tst_exit();
}

/*
 * do_child - make the call as the child process
 */
void do_child(void)
{
	int i, lc;

	/* The following loop checks looping state if -i option given */

	for (lc = 0; TEST_LOOPING(lc); lc++) {
		/* reset tst_count in case we are looping */
		tst_count = 0;

		/* loop through the test cases */
		for (i = 0; i < TST_TOTAL; i++) {
			/*
			 * use the TEST() macro to make the call
			 */

			TEST(shmctl(*(TC[i].shmid), TC[i].cmd, TC[i].sbuf));

			if (TEST_RETURN != -1) {
				tst_resm(TFAIL, "call succeeded unexpectedly");
				continue;
			}

			if (TEST_ERRNO == TC[i].error) {
				tst_resm(TPASS, "expected failure - errno = "
					 "%d : %s", TEST_ERRNO,
					 strerror(TEST_ERRNO));
			} else {
				tst_resm(TFAIL, "call failed with an "
					 "unexpected error - %d : %s",
					 TEST_ERRNO, strerror(TEST_ERRNO));
			}
		}
	}
}

/*
 * setup() - performs all the ONE TIME setup for this test.
 */
void setup(void)
{
	tst_require_root();

	tst_sig(FORK, DEF_HANDLER, cleanup);

	TEST_PAUSE;

	/*
	 * Create a temporary directory and cd into it.
	 * This helps to ensure that a unique msgkey is created.
	 * See libs/libltpipc/libipc.c for more information.
	 */
	tst_tmpdir();

	/* get an IPC resource key */
	shmkey = getipckey();

	/* create a shared memory segment with read and write permissions */
	if ((shm_id_1 = shmget(shmkey, SHM_SIZE, IPC_CREAT | IPC_EXCL |
			       SHM_RW)) == -1) {
		tst_brkm(TBROK, cleanup, "couldn't create shared memory "
			 "segment in setup()");
	}

	/* get the userid for a non root user */
	ltp_uid = getuserid(ltp_user);
}

/*
 * cleanup() - performs all the ONE TIME cleanup for this test at completion
 * 	       or premature exit.
 */
void cleanup(void)
{

}