testcases/kernel/syscalls/ipc/msgctl/msgctl02.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) International Business Machines Corp., 2001
 *    03/2001 - Written by Wayne Boyer
 * Copyright (c) 2018 Cyril Hrubis <chrubis@suse.cz>
 */
/*
 * Create a message queue, then issue the IPC_SET command to lower the
 * msg_qbytes value.
 */

#include <errno.h>

#include "tst_test.h"
#include "tst_safe_sysv_ipc.h"
#include "libnewipc.h"

static int msg_id = -1;
struct msqid_ds orig_buf;

static void verify_msgctl(void)
{
	struct msqid_ds buf = orig_buf;

	buf.msg_qbytes -= 1;

	TEST(msgctl(msg_id, IPC_SET, &buf));

	if (TST_RET != 0) {
		tst_res(TFAIL | TTERRNO, "msgctl(IPC_SET) failed");
		return;
	}

	tst_res(TPASS, "msgctl(IPC_SET) msg_qbytes - 1");

	memset(&buf, 0, sizeof(buf));
	SAFE_MSGCTL(msg_id, IPC_STAT, &buf);

	if (buf.msg_qbytes == orig_buf.msg_qbytes - 1) {
		tst_res(TPASS, "msg_qbytes = %lu",
			(unsigned long)buf.msg_qbytes);
	} else {
		tst_res(TFAIL, "msg_qbytes = %lu, expected %lu",
			(unsigned long)buf.msg_qbytes,
			(unsigned long)orig_buf.msg_qbytes - 1);
	}

	SAFE_MSGCTL(msg_id, IPC_SET, &orig_buf);
}

static void setup(void)
{
	key_t msgkey = GETIPCKEY();

	msg_id = SAFE_MSGGET(msgkey, IPC_CREAT | IPC_EXCL | MSG_RW | 0660);

	SAFE_MSGCTL(msg_id, IPC_STAT, &orig_buf);
}

static void cleanup(void)
{
	if (msg_id >= 0)
		SAFE_MSGCTL(msg_id, IPC_RMID, NULL);
}

static struct tst_test test = {
	.setup = setup,
	.cleanup = cleanup,
	.test_all = verify_msgctl,
	.needs_tmpdir = 1
};