/**

 * Seccomp Library test program

 *

 * Copyright (c) 2018 Oracle and/or its affiliates.  All rights reserved.

 * Author: Tom Hromatka <tom.hromatka@oracle.com>

 */

/*

 * This library is free software; you can redistribute it and/or modify it

 * under the terms of version 2.1 of the GNU Lesser General Public License as

 * published by the Free Software Foundation.

 *

 * This library 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 Lesser General Public License

 * for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this library; if not, see <http://www.gnu.org/licenses>.

 */

#include <errno.h>

#include <fcntl.h>

#include <pthread.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <unistd.h>

#include <seccomp.h>

#include "util.h"

static const unsigned int whitelist[] = {

	SCMP_SYS(clone),

	SCMP_SYS(exit),

	SCMP_SYS(exit_group),

	SCMP_SYS(futex),

	SCMP_SYS(madvise),

	SCMP_SYS(mmap),

	SCMP_SYS(mprotect),

	SCMP_SYS(munmap),

	SCMP_SYS(nanosleep),

	SCMP_SYS(set_robust_list),

};

/**

 * Child thread created via pthread_create()

 *

 * This thread will call a disallowed syscall.  It should

 * cause the entire program to die (and not just this

 * thread.)

 */

void *child_start(void *param)

{

	int fd;

	/* make a disallowed syscall */

	fd = open("/dev/null", O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);

	/* we should never get here.  seccomp should kill the entire

	 * process when open() is called. */

	if (fd >= 0)

		close(fd);

	return NULL;

}

int main(int argc, char *argv[])

{

	int rc, i;

	scmp_filter_ctx ctx = NULL;

	pthread_t child_thread;

	ctx = seccomp_init(SCMP_ACT_KILL_PROCESS);

	if (ctx == NULL)

		return ENOMEM;

	for (i = 0; i < sizeof(whitelist) / sizeof(whitelist[0]); i++) {

		rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, whitelist[i], 0);

		if (rc != 0)

			goto out;

	}

	rc = seccomp_load(ctx);

	if (rc != 0)

		goto out;

	rc = pthread_create(&child_thread, NULL, child_start, NULL);

	if (rc != 0)

		goto out;

	/* sleep for a bit to ensure that the child thread has time to run */

	sleep(1);

	/* we should never get here! */

	rc = -EACCES;

	goto out;

out:

	seccomp_release(ctx);

	return (rc < 0 ? -rc : rc);

}