/* SPDX-License-Identifier: MIT */
/*
 * Description: run various openat(2) tests
 *
 */
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/uio.h>

#include "helpers.h"
#include "liburing.h"

static int test_openat2(struct io_uring *ring, const char *path, int dfd,
			bool direct, int fixed_index)
{
	struct io_uring_cqe *cqe;
	struct io_uring_sqe *sqe;
	struct open_how how;
	int ret;

	sqe = io_uring_get_sqe(ring);
	if (!sqe) {
		fprintf(stderr, "get sqe failed\n");
		return -1;
	}
	memset(&how, 0, sizeof(how));
	how.flags = O_RDWR;

	if (!direct)
		io_uring_prep_openat2(sqe, dfd, path, &how);
	else
		io_uring_prep_openat2_direct(sqe, dfd, path, &how, fixed_index);

	ret = io_uring_submit(ring);
	if (ret <= 0) {
		fprintf(stderr, "sqe submit failed: %d\n", ret);
		return -1;
	}

	ret = io_uring_wait_cqe(ring, &cqe);
	if (ret < 0) {
		fprintf(stderr, "wait completion %d\n", ret);
		return -1;
	}
	ret = cqe->res;
	io_uring_cqe_seen(ring, cqe);

	if (direct && ret > 0) {
		close(ret);
		return -EINVAL;
	}
	return ret;
}

static int test_open_fixed(const char *path, int dfd)
{
	struct io_uring_cqe *cqe;
	struct io_uring_sqe *sqe;
	struct io_uring ring;
	const char pattern = 0xac;
	char buffer[] = { 0, 0 };
	int i, ret, fd = -1;

	ret = io_uring_queue_init(8, &ring, 0);
	if (ret) {
		fprintf(stderr, "ring setup failed\n");
		return -1;
	}
	ret = io_uring_register_files(&ring, &fd, 1);
	if (ret) {
		fprintf(stderr, "%s: register ret=%d\n", __FUNCTION__, ret);
		return -1;
	}

	ret = test_openat2(&ring, path, dfd, true, 0);
	if (ret == -EINVAL) {
		printf("fixed open isn't supported\n");
		return 1;
	} else if (ret) {
		fprintf(stderr, "direct open failed %d\n", ret);
		return -1;
	}

	sqe = io_uring_get_sqe(&ring);
	io_uring_prep_write(sqe, 0, &pattern, 1, 0);
	sqe->user_data = 1;
	sqe->flags |= IOSQE_FIXED_FILE | IOSQE_IO_LINK;

	sqe = io_uring_get_sqe(&ring);
	io_uring_prep_read(sqe, 0, buffer, 1, 0);
	sqe->user_data = 2;
	sqe->flags |= IOSQE_FIXED_FILE;

	ret = io_uring_submit(&ring);
	if (ret != 2) {
		fprintf(stderr, "%s: got %d, wanted 2\n", __FUNCTION__, ret);
		return -1;
	}

	for (i = 0; i < 2; i++) {
		ret = io_uring_wait_cqe(&ring, &cqe);
		if (ret < 0) {
			fprintf(stderr, "wait completion %d\n", ret);
			return -1;
		}
		if (cqe->res != 1) {
			fprintf(stderr, "unexpectetd ret %d\n", cqe->res);
			return -1;
		}
		io_uring_cqe_seen(&ring, cqe);
	}
	if (memcmp(&pattern, buffer, 1) != 0) {
		fprintf(stderr, "buf validation failed\n");
		return -1;
	}

	io_uring_queue_exit(&ring);
	return 0;
}

static int test_open_fixed_fail(const char *path, int dfd)
{
	struct io_uring ring;
	int ret, fd = -1;

	ret = io_uring_queue_init(8, &ring, 0);
	if (ret) {
		fprintf(stderr, "ring setup failed\n");
		return -1;
	}

	ret = test_openat2(&ring, path, dfd, true, 0);
	if (ret != -ENXIO) {
		fprintf(stderr, "install into not existing table, %i\n", ret);
		return 1;
	}

	ret = io_uring_register_files(&ring, &fd, 1);
	if (ret) {
		fprintf(stderr, "%s: register ret=%d\n", __FUNCTION__, ret);
		return -1;
	}

	ret = test_openat2(&ring, path, dfd, true, 1);
	if (ret != -EINVAL) {
		fprintf(stderr, "install out of bounds, %i\n", ret);
		return -1;
	}

	ret = test_openat2(&ring, path, dfd, true, (1u << 16));
	if (ret != -EINVAL) {
		fprintf(stderr, "install out of bounds or u16 overflow, %i\n", ret);
		return -1;
	}

	ret = test_openat2(&ring, path, dfd, true, (1u << 16) + 1);
	if (ret != -EINVAL) {
		fprintf(stderr, "install out of bounds or u16 overflow, %i\n", ret);
		return -1;
	}

	io_uring_queue_exit(&ring);
	return 0;
}

static int test_direct_reinstall(const char *path, int dfd)
{
	struct io_uring_cqe *cqe;
	struct io_uring_sqe *sqe;
	char buf[1] = { 0xfa };
	struct io_uring ring;
	int ret, pipe_fds[2];
	ssize_t ret2;

	if (pipe2(pipe_fds, O_NONBLOCK)) {
		fprintf(stderr, "pipe() failed\n");
		return -1;
	}
	ret = io_uring_queue_init(8, &ring, 0);
	if (ret) {
		fprintf(stderr, "ring setup failed\n");
		return -1;
	}
	ret = io_uring_register_files(&ring, pipe_fds, 2);
	if (ret) {
		fprintf(stderr, "%s: register ret=%d\n", __FUNCTION__, ret);
		return -1;
	}

	/* reinstall into the second slot */
	ret = test_openat2(&ring, path, dfd, true, 1);
	if (ret != 0) {
		fprintf(stderr, "reinstall failed, %i\n", ret);
		return -1;
	}

	/* verify it's reinstalled, first write into the slot... */
	sqe = io_uring_get_sqe(&ring);
	io_uring_prep_write(sqe, 1, buf, sizeof(buf), 0);
	sqe->flags |= IOSQE_FIXED_FILE;

	ret = io_uring_submit(&ring);
	if (ret != 1) {
		fprintf(stderr, "sqe submit failed: %d\n", ret);
		return -1;
	}
	ret = io_uring_wait_cqe(&ring, &cqe);
	if (ret < 0) {
		fprintf(stderr, "wait completion %d\n", ret);
		return ret;
	}
	ret = cqe->res;
	io_uring_cqe_seen(&ring, cqe);
	if (ret != 1) {
		fprintf(stderr, "invalid write %i\n", ret);
		return -1;
	}

	/* ... and make sure nothing has been written to the pipe */
	ret2 = read(pipe_fds[0], buf, 1);
	if (ret2 != 0 && !(ret2 < 0 && errno == EAGAIN)) {
		fprintf(stderr, "invalid pipe read, %d %d\n", errno, (int)ret2);
		return -1;
	}

	close(pipe_fds[0]);
	close(pipe_fds[1]);
	io_uring_queue_exit(&ring);
	return 0;
}

int main(int argc, char *argv[])
{
	struct io_uring ring;
	const char *path, *path_rel;
	int ret, do_unlink;

	ret = io_uring_queue_init(8, &ring, 0);
	if (ret) {
		fprintf(stderr, "ring setup failed\n");
		return 1;
	}

	if (argc > 1) {
		path = "/tmp/.open.at2";
		path_rel = argv[1];
		do_unlink = 0;
	} else {
		path = "/tmp/.open.at2";
		path_rel = ".open.at2";
		do_unlink = 1;
	}

	t_create_file(path, 4096);

	if (do_unlink)
		t_create_file(path_rel, 4096);

	ret = test_openat2(&ring, path, -1, false, 0);
	if (ret < 0) {
		if (ret == -EINVAL) {
			fprintf(stdout, "openat2 not supported, skipping\n");
			goto done;
		}
		fprintf(stderr, "test_openat2 absolute failed: %d\n", ret);
		goto err;
	}

	ret = test_openat2(&ring, path_rel, AT_FDCWD, false, 0);
	if (ret < 0) {
		fprintf(stderr, "test_openat2 relative failed: %d\n", ret);
		goto err;
	}

	ret = test_open_fixed(path, -1);
	if (ret > 0)
		goto done;
	if (ret) {
		fprintf(stderr, "test_open_fixed failed\n");
		goto err;
	}
	ret = test_open_fixed_fail(path, -1);
	if (ret) {
		fprintf(stderr, "test_open_fixed_fail failed\n");
		goto err;
	}

	ret = test_direct_reinstall(path, -1);
	if (ret) {
		fprintf(stderr, "test_direct_reinstall failed\n");
		goto err;
	}

done:
	unlink(path);
	if (do_unlink)
		unlink(path_rel);
	return 0;
err:
	unlink(path);
	if (do_unlink)
		unlink(path_rel);
	return 1;
}