testcases/open_posix_testsuite/conformance/interfaces/shm_open/34-1.c

/*
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2.
 *
 *  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.
 *
 * Test that the shm_open() function sets errno = EACCES if O_TRUNC is
 * specified and write permission is denied
 */

/* FIXME : ambiguite de la spec */

#define _XOPEN_SOURCE 600

#include <stdio.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <pwd.h>
#include <string.h>
#include "posixtest.h"

#define SHM_NAME "posixtest_34-1"

/** Set the euid of this process to a non-root uid */
int set_nonroot()
{
	struct passwd *pw;
	setpwent();
	/* search for the first user which is non root */
	while ((pw = getpwent()) != NULL)
		if (strcmp(pw->pw_name, "root"))
			break;
	endpwent();
	if (pw == NULL) {
		printf("There is no other user than current and root.\n");
		return 1;
	}

	if (seteuid(pw->pw_uid) != 0) {
		if (errno == EPERM) {
			printf
			    ("You don't have permission to change your UID.\n");
			return 1;
		}
		perror("An error occurs when calling seteuid()");
		return 1;
	}

	printf("Testing with user '%s' (uid: %d)\n",
	       pw->pw_name, (int)geteuid());
	return 0;
}

int main(void)
{
	int fd;

	/* This test should be run under standard user permissions */
	if (getuid() == 0) {
		if (set_nonroot() != 0) {
			printf("Cannot run this test as non-root user\n");
			return PTS_UNTESTED;
		}
	}

	fd = shm_open(SHM_NAME, O_RDWR | O_CREAT, S_IRUSR);
	if (fd == -1) {
		perror("An error occurs when calling shm_open()");
		return PTS_UNRESOLVED;
	}

	fd = shm_open(SHM_NAME, O_RDWR | O_TRUNC, 0);

	if (fd == -1 && errno == EACCES) {
		printf("Test PASSED\n");
		shm_unlink(SHM_NAME);
		return PTS_PASS;
	} else if (fd != -1) {
		printf("shm_open success.\n");
		shm_unlink(SHM_NAME);
		return PTS_FAIL;
	}

	perror("shm_open");
	return PTS_FAIL;
}