/* SPDX-License-Identifier: MIT */

/*

 * Check that IORING_OP_ACCEPT works, and send some data across to verify we

 * didn't get a junk fd.

 */

#include <stdio.h>

#include <stdlib.h>

#include <stdint.h>

#include <assert.h>

#include <errno.h>

#include <fcntl.h>

#include <unistd.h>

#include <sys/socket.h>

#include <sys/time.h>

#include <sys/resource.h>

#include <sys/un.h>

#include <netinet/tcp.h>

#include <netinet/in.h>

#include "liburing.h"

static int no_accept;

struct data {

	char buf[128];

	struct iovec iov;

};

static void queue_send(struct io_uring *ring, int fd)

{

	struct io_uring_sqe *sqe;

	struct data *d;

	d = malloc(sizeof(*d));

	d->iov.iov_base = d->buf;

	d->iov.iov_len = sizeof(d->buf);

	sqe = io_uring_get_sqe(ring);

	io_uring_prep_writev(sqe, fd, &d->iov, 1, 0);

}

static void queue_recv(struct io_uring *ring, int fd)

{

	struct io_uring_sqe *sqe;

	struct data *d;

	d = malloc(sizeof(*d));

	d->iov.iov_base = d->buf;

	d->iov.iov_len = sizeof(d->buf);

	sqe = io_uring_get_sqe(ring);

	io_uring_prep_readv(sqe, fd, &d->iov, 1, 0);

}

static int accept_conn(struct io_uring *ring, int fd)

{

	struct io_uring_sqe *sqe;

	struct io_uring_cqe *cqe;

	int ret;

	sqe = io_uring_get_sqe(ring);

	io_uring_prep_accept(sqe, fd, NULL, NULL, 0);

	assert(io_uring_submit(ring) != -1);

	assert(!io_uring_wait_cqe(ring, &cqe));

	ret = cqe->res;

	io_uring_cqe_seen(ring, cqe);

	return ret;

}

static int start_accept_listen(struct sockaddr_in *addr, int port_off)

{

	int fd;

	fd = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP);

	int32_t val = 1;

	assert(setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(val)) != -1);

	assert(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) != -1);

	struct sockaddr_in laddr;

	if (!addr)

		addr = &laddr;

	addr->sin_family = AF_INET;

	addr->sin_port = 0x1235 + port_off;

	addr->sin_addr.s_addr = 0x0100007fU;

	assert(bind(fd, (struct sockaddr*)addr, sizeof(*addr)) != -1);

	assert(listen(fd, 128) != -1);

	return fd;

}

static int test(struct io_uring *ring, int accept_should_error)

{

	struct io_uring_cqe *cqe;

	struct sockaddr_in addr;

	uint32_t head;

	uint32_t count = 0;

	int done = 0;

	int p_fd[2];

	int32_t val, recv_s0 = start_accept_listen(&addr, 0);

	p_fd[1] = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP);

	val = 1;

	assert(setsockopt(p_fd[1], IPPROTO_TCP, TCP_NODELAY, &val, sizeof(val)) != -1);

	int32_t flags = fcntl(p_fd[1], F_GETFL, 0);

	assert(flags != -1);

	flags |= O_NONBLOCK;

	assert(fcntl(p_fd[1], F_SETFL, flags) != -1);

	assert(connect(p_fd[1], (struct sockaddr*)&addr, sizeof(addr)) == -1);

	flags = fcntl(p_fd[1], F_GETFL, 0);

	assert(flags != -1);

	flags &= ~O_NONBLOCK;

	assert(fcntl(p_fd[1], F_SETFL, flags) != -1);

	p_fd[0] = accept_conn(ring, recv_s0);

	if (p_fd[0] == -EINVAL) {

		if (accept_should_error)

			goto out;

		fprintf(stdout, "Accept not supported, skipping\n");

		no_accept = 1;

		goto out;

	} else if (p_fd[0] < 0) {

		if (accept_should_error &&

		    (p_fd[0] == -EBADF || p_fd[0] == -EINVAL))

			goto out;

		fprintf(stderr, "Accept got %d\n", p_fd[0]);

		goto err;

	}

	queue_send(ring, p_fd[1]);

	queue_recv(ring, p_fd[0]);

	assert(io_uring_submit_and_wait(ring, 2) != -1);

	while (count < 2) {

		io_uring_for_each_cqe(ring, head, cqe) {

			if (cqe->res < 0) {

				fprintf(stderr, "Got cqe res %d\n", cqe->res);

				done = 1;

				break;

			}

			assert(cqe->res == 128);

			count++;

		}

		assert(count <= 2);

		io_uring_cq_advance(ring, count);

		if (done)

			goto err;

	}

out:

	close(p_fd[0]);

	close(p_fd[1]);

	return 0;

err:

	close(p_fd[0]);

	close(p_fd[1]);

	return 1;

}

static void sig_alrm(int sig)

{

	exit(0);

}

static int test_accept_pending_on_exit(void)

{

	struct io_uring m_io_uring;

	struct io_uring_cqe *cqe;

	struct io_uring_sqe *sqe;

	int fd;

	assert(io_uring_queue_init(32, &m_io_uring, 0) >= 0);

	fd = start_accept_listen(NULL, 0);

	sqe = io_uring_get_sqe(&m_io_uring);

	io_uring_prep_accept(sqe, fd, NULL, NULL, 0);

	assert(io_uring_submit(&m_io_uring) != -1);

	signal(SIGALRM, sig_alrm);

	alarm(1);

	assert(!io_uring_wait_cqe(&m_io_uring, &cqe));

	io_uring_cqe_seen(&m_io_uring, cqe);

	io_uring_queue_exit(&m_io_uring);

	return 0;

}

/*

 * Test issue many accepts and see if we handle cancellation on exit

 */

static int test_accept_many(unsigned nr, unsigned usecs)

{

	struct io_uring m_io_uring;

	struct io_uring_cqe *cqe;

	struct io_uring_sqe *sqe;

	unsigned long cur_lim;

	struct rlimit rlim;

	int *fds, i, ret = 0;

	if (getrlimit(RLIMIT_NPROC, &rlim) < 0) {

		perror("getrlimit");

		return 1;

	}

	cur_lim = rlim.rlim_cur;

	rlim.rlim_cur = nr / 4;

	if (setrlimit(RLIMIT_NPROC, &rlim) < 0) {

		perror("setrlimit");

		return 1;

	}

	assert(io_uring_queue_init(2 * nr, &m_io_uring, 0) >= 0);

	fds = calloc(nr, sizeof(int));

	for (i = 0; i < nr; i++)

		fds[i] = start_accept_listen(NULL, i);

	for (i = 0; i < nr; i++) {

		sqe = io_uring_get_sqe(&m_io_uring);

		io_uring_prep_accept(sqe, fds[i], NULL, NULL, 0);

		sqe->user_data = 1 + i;

		assert(io_uring_submit(&m_io_uring) == 1);

	}

	if (usecs)

		usleep(usecs);

	for (i = 0; i < nr; i++) {

		if (io_uring_peek_cqe(&m_io_uring, &cqe))

			break;

		if (cqe->res != -ECANCELED) {

			fprintf(stderr, "Expected cqe to be cancelled\n");

			goto err;

		}

		io_uring_cqe_seen(&m_io_uring, cqe);

	}

out:

	rlim.rlim_cur = cur_lim;

	if (setrlimit(RLIMIT_NPROC, &rlim) < 0) {

		perror("setrlimit");

		return 1;

	}

	free(fds);

	io_uring_queue_exit(&m_io_uring);

	return ret;

err:

	ret = 1;

	goto out;

}

static int test_accept_cancel(unsigned usecs)

{

	struct io_uring m_io_uring;

	struct io_uring_cqe *cqe;

	struct io_uring_sqe *sqe;

	int fd, i;

	assert(io_uring_queue_init(32, &m_io_uring, 0) >= 0);

	fd = start_accept_listen(NULL, 0);

	sqe = io_uring_get_sqe(&m_io_uring);

	io_uring_prep_accept(sqe, fd, NULL, NULL, 0);

	sqe->user_data = 1;

	assert(io_uring_submit(&m_io_uring) == 1);

	if (usecs)

		usleep(usecs);

	sqe = io_uring_get_sqe(&m_io_uring);

	io_uring_prep_cancel(sqe, (void *) 1, 0);

	sqe->user_data = 2;

	assert(io_uring_submit(&m_io_uring) == 1);

	for (i = 0; i < 2; i++) {

		assert(!io_uring_wait_cqe(&m_io_uring, &cqe));

		/*

		 * Two cases here:

		 *

		 * 1) We cancel the accept4() before it got started, we should

		 *    get '0' for the cancel request and '-ECANCELED' for the

		 *    accept request.

		 * 2) We cancel the accept4() after it's already running, we

		 *    should get '-EALREADY' for the cancel request and

		 *    '-EINTR' for the accept request.

		 */

		if (cqe->user_data == 1) {

			if (cqe->res != -EINTR && cqe->res != -ECANCELED) {

				fprintf(stderr, "Cancelled accept got %d\n", cqe->res);

				goto err;

			}

		} else if (cqe->user_data == 2) {

			if (cqe->res != -EALREADY && cqe->res != 0) {

				fprintf(stderr, "Cancel got %d\n", cqe->res);

				goto err;

			}

		}

		io_uring_cqe_seen(&m_io_uring, cqe);

	}

	io_uring_queue_exit(&m_io_uring);

	return 0;

err:

	io_uring_queue_exit(&m_io_uring);

	return 1;

}

static int test_accept(void)

{

	struct io_uring m_io_uring;

	int ret;

	assert(io_uring_queue_init(32, &m_io_uring, 0) >= 0);

	ret = test(&m_io_uring, 0);

	io_uring_queue_exit(&m_io_uring);

	return ret;

}

static int test_accept_sqpoll(void)

{

	struct io_uring m_io_uring;

	int ret;

	ret = io_uring_queue_init(32, &m_io_uring, IORING_SETUP_SQPOLL);

	if (ret && geteuid()) {

		printf("%s: skipped, not root\n", __FUNCTION__);

		return 0;

	} else if (ret)

		return ret;

	ret = test(&m_io_uring, 1);

	io_uring_queue_exit(&m_io_uring);

	return ret;

}

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

{

	int ret;

	if (argc > 1)

		return 0;

	ret = test_accept();

	if (ret) {

		fprintf(stderr, "test_accept failed\n");

		return ret;

	}

	if (no_accept)

		return 0;

	ret = test_accept_sqpoll();

	if (ret) {

		fprintf(stderr, "test_accept_sqpoll failed\n");

		return ret;

	}

	ret = test_accept_cancel(0);

	if (ret) {

		fprintf(stderr, "test_accept_cancel nodelay failed\n");

		return ret;

	}

	ret = test_accept_cancel(10000);

	if (ret) {

		fprintf(stderr, "test_accept_cancel delay failed\n");

		return ret;

	}

	ret = test_accept_many(128, 0);

	if (ret) {

		fprintf(stderr, "test_accept_many failed\n");

		return ret;

	}

	ret = test_accept_many(128, 100000);

	if (ret) {

		fprintf(stderr, "test_accept_many failed\n");

		return ret;

	}

	ret = test_accept_pending_on_exit();

	if (ret) {

		fprintf(stderr, "test_accept_pending_on_exit failed\n");

		return ret;

	}

	return 0;

}