/**

 * Seccomp Library test program

 *

 * Copyright (c) 2019 Cisco Systems, Inc. <pmoore2@cisco.com>

 * Author: Paul Moore <paul@paul-moore.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 <sys/types.h>

#include <sys/wait.h>

#include <asm/unistd.h>

#include <unistd.h>

#include <seccomp.h>

#include <signal.h>

#include <syscall.h>

#include <errno.h>

#include <stdlib.h>

#include "util.h"

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

{

	int rc, fd = -1, status;

	struct seccomp_notif *req = NULL;

	struct seccomp_notif_resp *resp = NULL;

	scmp_filter_ctx ctx = NULL;

	pid_t pid = 0, magic;

	magic = getpid();

	ctx = seccomp_init(SCMP_ACT_ALLOW);

	if (ctx == NULL)

		return ENOMEM;

	rc = seccomp_attr_set(ctx, SCMP_FLTATR_CTL_TSYNC, 1);

	if (rc)

		goto out;

	rc = seccomp_rule_add(ctx, SCMP_ACT_NOTIFY, SCMP_SYS(getpid), 0, NULL);

	if (rc)

		goto out;

	rc  = seccomp_load(ctx);

	if (rc < 0)

		goto out;

	rc = seccomp_notify_fd(ctx);

	if (rc < 0)

		goto out;

	fd = rc;

	pid = fork();

	if (pid == 0)

		exit(syscall(__NR_getpid) != magic);

	rc = seccomp_notify_alloc(&req, &resp);

	if (rc)

		goto out;

	rc = seccomp_notify_receive(fd, req);

	if (rc)

		goto out;

	if (req->data.nr != __NR_getpid) {

		rc = -EFAULT;

		goto out;

	}

	rc = seccomp_notify_id_valid(fd, req->id);

	if (rc)

		goto out;

	resp->id = req->id;

	resp->val = magic;

	resp->error = 0;

	resp->flags = 0;

	rc = seccomp_notify_respond(fd, resp);

	if (rc)

		goto out;

	if (waitpid(pid, &status, 0) != pid) {

		rc = -EFAULT;

		goto out;

	}

	if (!WIFEXITED(status)) {

		rc = -EFAULT;

		goto out;

	}

	if (WEXITSTATUS(status)) {

		rc = -EFAULT;

		goto out;

	}

out:

	if (fd >= 0)

		close(fd);

	if (pid)

		kill(pid, SIGKILL);

	seccomp_notify_free(req, resp);

	seccomp_release(ctx);

	if (rc != 0)

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

	return 160;

}