test/msg-ring-fd: add test case for FD passing with MSG_RING

Basic test cases that tests both local and "remote" delivery of
a fixed file descriptor from one ring to another.

Signed-off-by: Jens Axboe <[email protected]>

test/Makefile

@@ -115,6 +115,7 @@ test_srcs := \
  madvise.c \
  mkdir.c \
  msg-ring.c \
+ msg-ring-fd.c \
  msg-ring-flags.c \
  msg-ring-overflow.c \
  multicqes_drain.c \

test/msg-ring-fd.c

@@ -0,0 +1,283 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Description: test fd passing with MSG_RING
+ *
+ */
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <pthread.h>
+
+#include "liburing.h"
+#include "helpers.h"
+
+static int no_msg;
+
+struct data {
+ pthread_t thread;
+ pthread_barrier_t barrier;
+ int ring_flags;
+ int ring_fd;
+ char buf[32];
+};
+
+static void *thread_fn(void *__data)
+{
+ struct io_uring_sqe *sqe;
+ struct io_uring_cqe *cqe;
+ struct data *d = __data;
+ struct io_uring ring;
+ int ret, fd = -1;
+
+ io_uring_queue_init(8, &ring, d->ring_flags);
+ ret = io_uring_register_files(&ring, &fd, 1);
+ if (ret) {
+ fprintf(stderr, "thread file register: %d\n", ret);
+ return NULL;
+ }
+
+ d->ring_fd = ring.ring_fd;
+ pthread_barrier_wait(&d->barrier);
+
+ /* wait for MSG */
+ ret = io_uring_wait_cqe(&ring, &cqe);
+ if (ret) {
+ fprintf(stderr, "wait_cqe dst: %d\n", ret);
+ return NULL;
+ }
+ if (cqe->res < 0) {
+ fprintf(stderr, "cqe error dst: %d\n", cqe->res);
+ return NULL;
+ }
+
+ fd = cqe->res;
+ sqe = io_uring_get_sqe(&ring);
+ io_uring_prep_read(sqe, fd, d->buf, sizeof(d->buf), 0);
+ sqe->flags |= IOSQE_FIXED_FILE;
+ io_uring_submit(&ring);
+
+ ret = io_uring_wait_cqe(&ring, &cqe);
+ if (ret) {
+ fprintf(stderr, "wait_cqe dst: %d\n", ret);
+ return NULL;
+ }
+ if (cqe->res < 0) {
+ fprintf(stderr, "cqe error dst: %d\n", cqe->res);
+ return NULL;
+ }
+
+ io_uring_queue_exit(&ring);
+ return NULL;
+}
+
+static int test_remote(struct io_uring *src, int ring_flags)
+{
+ struct io_uring_sqe *sqe;
+ struct io_uring_cqe *cqe;
+ int fds[2], fd, ret;
+ struct data d;
+ char buf[32];
+ void *tret;
+ int i;
+
+ pthread_barrier_init(&d.barrier, NULL, 2);
+ d.ring_flags = ring_flags;
+ pthread_create(&d.thread, NULL, thread_fn, &d);
+ pthread_barrier_wait(&d.barrier);
+ memset(d.buf, 0, sizeof(d.buf));
+
+ if (pipe(fds) < 0) {
+ perror("pipe");
+ return 1;
+ }
+
+ fd = fds[0];
+ ret = io_uring_register_files(src, &fd, 1);
+ if (ret) {
+ fprintf(stderr, "register files failed: %d\n", ret);
+ return 1;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(buf); i++)
+ buf[i] = rand();
+
+ sqe = io_uring_get_sqe(src);
+ io_uring_prep_write(sqe, fds[1], buf, sizeof(buf), 0);
+ sqe->user_data = 1;
+
+ sqe = io_uring_get_sqe(src);
+ io_uring_prep_msg_ring_fd(sqe, d.ring_fd, 0, 0, 0, 0);
+ sqe->user_data = 2;
+
+ io_uring_submit(src);
+
+ for (i = 0; i < 2; i++) {
+ ret = io_uring_wait_cqe(src, &cqe);
+ if (ret) {
+ fprintf(stderr, "wait_cqe: %d\n", ret);
+ return 1;
+ }
+ io_uring_cqe_seen(src, cqe);
+ }
+
+ pthread_join(d.thread, &tret);
+
+ if (memcmp(buf, d.buf, sizeof(buf))) {
+ fprintf(stderr, "buffers differ\n");
+ return 1;
+ }
+
+ close(fds[0]);
+ close(fds[1]);
+ io_uring_unregister_files(src);
+ return 0;
+}
+
+static int test_local(struct io_uring *src, struct io_uring *dst)
+{
+ struct io_uring_sqe *sqe;
+ struct io_uring_cqe *cqe;
+ int fds[2], fd, ret;
+ char buf[32], dst_buf[32];
+ int i;
+
+ fd = -1;
+ ret = io_uring_register_files(dst, &fd, 1);
+ if (ret) {
+ fprintf(stderr, "register files failed: %d\n", ret);
+ return 1;
+ }
+
+ if (pipe(fds) < 0) {
+ perror("pipe");
+ return 1;
+ }
+
+ fd = fds[0];
+ ret = io_uring_register_files(src, &fd, 1);
+ if (ret) {
+ fprintf(stderr, "register files failed: %d\n", ret);
+ return 1;
+ }
+
+ memset(dst_buf, 0, sizeof(dst_buf));
+ for (i = 0; i < ARRAY_SIZE(buf); i++)
+ buf[i] = rand();
+
+ sqe = io_uring_get_sqe(src);
+ io_uring_prep_write(sqe, fds[1], buf, sizeof(buf), 0);
+ sqe->user_data = 1;
+
+ sqe = io_uring_get_sqe(src);
+ io_uring_prep_msg_ring_fd(sqe, dst->ring_fd, 0, 0, 0, 0);
+ sqe->user_data = 2;
+
+ io_uring_submit(src);
+
+ for (i = 0; i < 2; i++) {
+ ret = io_uring_wait_cqe(src, &cqe);
+ if (ret) {
+ fprintf(stderr, "wait_cqe: %d\n", ret);
+ return 1;
+ }
+ io_uring_cqe_seen(src, cqe);
+ }
+
+ ret = io_uring_wait_cqe(dst, &cqe);
+ if (ret) {
+ fprintf(stderr, "wait_cqe dst: %d\n", ret);
+ return 1;
+ }
+ if (cqe->res < 0) {
+ fprintf(stderr, "cqe error dst: %d\n", cqe->res);
+ return 1;
+ }
+
+ fd = cqe->res;
+ sqe = io_uring_get_sqe(dst);
+ io_uring_prep_read(sqe, fd, dst_buf, sizeof(dst_buf), 0);
+ sqe->flags |= IOSQE_FIXED_FILE;
+ io_uring_submit(dst);
+
+ ret = io_uring_wait_cqe(dst, &cqe);
+ if (ret) {
+ fprintf(stderr, "wait_cqe dst: %d\n", ret);
+ return 1;
+ }
+ if (cqe->res < 0) {
+ fprintf(stderr, "cqe error dst: %d\n", cqe->res);
+ return 1;
+ }
+ if (memcmp(buf, dst_buf, sizeof(buf))) {
+ fprintf(stderr, "buffers differ\n");
+ return 1;
+ }
+
+ close(fds[0]);
+ close(fds[1]);
+ io_uring_unregister_files(src);
+ io_uring_unregister_files(dst);
+ return 0;
+}
+
+static int test(int ring_flags)
+{
+ struct io_uring ring, ring2;
+ int ret;
+
+ ret = io_uring_queue_init(8, &ring, ring_flags);
+ if (ret) {
+ fprintf(stderr, "ring setup failed: %d\n", ret);
+ return T_EXIT_FAIL;
+ }
+ ret = io_uring_queue_init(8, &ring2, ring_flags);
+ if (ret) {
+ fprintf(stderr, "ring setup failed: %d\n", ret);
+ return T_EXIT_FAIL;
+ }
+
+ ret = test_local(&ring, &ring2);
+ if (ret) {
+ fprintf(stderr, "test local failed\n");
+ return T_EXIT_FAIL;
+ }
+ if (no_msg)
+ return T_EXIT_SKIP;
+
+ ret = test_remote(&ring, ring_flags);
+ if (ret) {
+ fprintf(stderr, "test_remote failed\n");
+ return T_EXIT_FAIL;
+ }
+
+ io_uring_queue_exit(&ring);
+ io_uring_queue_exit(&ring2);
+ return T_EXIT_PASS;
+}
+
+int main(int argc, char *argv[])
+{
+ int ret;
+
+ if (argc > 1)
+ return T_EXIT_SKIP;
+
+ ret = test(0);
+ if (ret != T_EXIT_PASS) {
+ fprintf(stderr, "ring flags 0 failed\n");
+ return ret;
+ }
+ if (no_msg)
+ return T_EXIT_SKIP;
+
+ ret = test(IORING_SETUP_SINGLE_ISSUER|IORING_SETUP_DEFER_TASKRUN);
+ if (ret != T_EXIT_PASS) {
+ fprintf(stderr, "ring flags defer failed\n");
+ return ret;
+ }
+
+ return ret;
+}