testcases/kernel/syscalls/ipc/msgsnd/msgsnd05.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) International Business Machines Corp., 2001
 */

/*
 * DESCRIPTION
 * 1) msgsnd(2) fails and sets errno to EAGAIN if the message can't be
 *    sent due to the msg_qbytes limit for the queue and IPC_NOWAIT is
 *    specified.
 * 2) msgsnd(2) fails and sets errno to EINTR if msgsnd(2) sleeps on a
 *    full message queue condition and the process catches a signal.
 */

#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>

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

static key_t msgkey;
static int queue_id = -1;
static struct buf {
	long type;
	char text[MSGSIZE];
} snd_buf = {1, "hello"};

static struct tcase {
	int flag;
	int exp_err;
	/*1: nobody expected  0: root expected */
	int exp_user;
} tcases[] = {
	{IPC_NOWAIT, EAGAIN, 0},
	{0, EINTR, 1}
};

static void verify_msgsnd(struct tcase *tc)
{
	TEST(msgsnd(queue_id, &snd_buf, MSGSIZE, tc->flag));
	if (TST_RET != -1) {
		tst_res(TFAIL, "msgsnd() succeeded unexpectedly");
		return;
	}

	if (TST_ERR == tc->exp_err) {
		tst_res(TPASS | TTERRNO, "msgsnd() failed as expected");
	} else {
		tst_res(TFAIL | TTERRNO, "msgsnd() failed unexpectedly,"
			" expected %s", tst_strerrno(tc->exp_err));
	}
}

static void sighandler(int sig)
{
	if (sig == SIGHUP)
		return;
	else
		_exit(TBROK);
}

static void do_test(unsigned int n)
{
	pid_t pid;
	struct tcase *tc = &tcases[n];

	if (tc->exp_user == 0) {
		verify_msgsnd(tc);
		return;
	}

	pid = SAFE_FORK();
	if (!pid) {
		SAFE_SIGNAL(SIGHUP, sighandler);
		verify_msgsnd(tc);
		_exit(0);
	}

	TST_PROCESS_STATE_WAIT(pid, 'S', 0);
	SAFE_KILL(pid, SIGHUP);
	tst_reap_children();
}

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

	queue_id = SAFE_MSGGET(msgkey, IPC_CREAT | IPC_EXCL | MSG_RW);

	while (msgsnd(queue_id, &snd_buf, MSGSIZE, IPC_NOWAIT) != -1)
		snd_buf.type += 1;
}

static void cleanup(void)
{
	if (queue_id != -1)
		SAFE_MSGCTL(queue_id, IPC_RMID, NULL);
}

static struct tst_test test = {
	.needs_tmpdir = 1,
	.needs_root = 1,
	.forks_child = 1,
	.tcnt = ARRAY_SIZE(tcases),
	.setup = setup,
	.cleanup = cleanup,
	.test = do_test
};