/*
 * Copyright (c) Huawei Technologies Co., Ltd., 2015
 * 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.
 */

/*
 * Verify that:
 * The kernel imposes a limit of 32 nested levels of pid namespaces.
 */

#define _GNU_SOURCE
#include <sys/wait.h>
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include "test.h"
#include "pidns_helper.h"

#define MAXNEST 32

char *TCID = "pidns32";
int TST_TOTAL = 1;

static void setup(void)
{
	tst_require_root();
	check_newpid();
	tst_tmpdir();
}

static void cleanup(void)
{
	tst_rmdir();
}

static int child_fn1(void *arg)
{
	pid_t cpid1;
	long level = (long)arg;
	int status;

	if (level == MAXNEST)
		return 0;
	cpid1 = ltp_clone_quick(CLONE_NEWPID | SIGCHLD,
		(void *)child_fn1, (void *)(level + 1));
	if (cpid1 < 0) {
		printf("level %ld:unexpected error: (%d) %s\n",
			level, errno, strerror(errno));
		return 1;
	}
	if (waitpid(cpid1, &status, 0) == -1)
		return 1;

	if (WIFEXITED(status) && WEXITSTATUS(status) != 0) {
		printf("child exited abnormally\n");
		return 1;
	} else if (WIFSIGNALED(status)) {
		printf("child was killed with signal = %d", WTERMSIG(status));
		return 1;
	}
	return 0;
}

static void test_max_nest(void)
{
	pid_t cpid1;

	cpid1 = ltp_clone_quick(CLONE_NEWPID | SIGCHLD,
		(void *)child_fn1, (void *)1);
	if (cpid1 < 0)
		tst_brkm(TBROK | TERRNO, cleanup, "clone failed");

	tst_record_childstatus(cleanup, cpid1);
}

int main(int argc, char *argv[])
{
	int lc;

	setup();
	tst_parse_opts(argc, argv, NULL, NULL);

	for (lc = 0; TEST_LOOPING(lc); lc++) {
		tst_count = 0;
		test_max_nest();
	}

	cleanup();
	tst_exit();
}
