From: Gabriel Krisman Bertazi <krisman@xxxxxxx>
Date: Fri, 14 Jun 2024 12:30:46 -0400
> IORING_OP_BIND provides the semantic of bind(2) via io_uring. While
> this is an essentially synchronous system call, the main point is to
> enable a network path to execute fully with io_uring registered and
> descriptorless files.
>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxx>
>
> ---
> changes since v1:
> - drop explocit error handling for move_addr_to_kernel (jens)
> - Remove empty line ahead of return;
> ---
> include/uapi/linux/io_uring.h | 1 +
> io_uring/net.c | 36 +++++++++++++++++++++++++++++++++++
> io_uring/net.h | 3 +++
> io_uring/opdef.c | 13 +++++++++++++
> 4 files changed, 53 insertions(+)
>
> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
> index 994bf7af0efe..4ef153d95c87 100644
> --- a/include/uapi/linux/io_uring.h
> +++ b/include/uapi/linux/io_uring.h
> @@ -257,6 +257,7 @@ enum io_uring_op {
> IORING_OP_FUTEX_WAITV,
> IORING_OP_FIXED_FD_INSTALL,
> IORING_OP_FTRUNCATE,
> + IORING_OP_BIND,
>
> /* this goes last, obviously */
> IORING_OP_LAST,
> diff --git a/io_uring/net.c b/io_uring/net.c
> index 0a48596429d9..8cbc29aff15c 100644
> --- a/io_uring/net.c
> +++ b/io_uring/net.c
> @@ -51,6 +51,11 @@ struct io_connect {
> bool seen_econnaborted;
> };
>
> +struct io_bind {
> + struct file *file;
> + int addr_len;
> +};
> +
> struct io_sr_msg {
> struct file *file;
> union {
> @@ -1715,6 +1720,37 @@ int io_connect(struct io_kiocb *req, unsigned int issue_flags)
> return IOU_OK;
> }
>
> +int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
> +{
> + struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
> + struct sockaddr __user *uaddr;
> + struct io_async_msghdr *io;
> +
> + if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
> + return -EINVAL;
> +
> + uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
> + bind->addr_len = READ_ONCE(sqe->addr2);
^^
nit: double space
> +
> + io = io_msg_alloc_async(req);
> + if (unlikely(!io))
> + return -ENOMEM;
> + return move_addr_to_kernel(uaddr, bind->addr_len, &io->addr);
> +}
> +
> +int io_bind(struct io_kiocb *req, unsigned int issue_flags)
> +{
> + struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
> + struct io_async_msghdr *io = req->async_data;
> + int ret;
> +
> + ret = __sys_bind_socket(sock_from_file(req->file), &io->addr, bind->addr_len);
^^
ditto
> + if (ret < 0)
> + req_set_fail(req);
> + io_req_set_res(req, ret, 0);
> + return 0;
> +}
> +
> void io_netmsg_cache_free(const void *entry)
> {
> struct io_async_msghdr *kmsg = (struct io_async_msghdr *) entry;
> diff --git a/io_uring/net.h b/io_uring/net.h
> index 0eb1c1920fc9..49f9a7bc1113 100644
> --- a/io_uring/net.h
> +++ b/io_uring/net.h
> @@ -49,6 +49,9 @@ int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags);
> int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
> void io_send_zc_cleanup(struct io_kiocb *req);
>
> +int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
> +int io_bind(struct io_kiocb *req, unsigned int issue_flags);
> +
> void io_netmsg_cache_free(const void *entry);
> #else
> static inline void io_netmsg_cache_free(const void *entry)
> diff --git a/io_uring/opdef.c b/io_uring/opdef.c
> index 2de5cca9504e..19ee9445f024 100644
> --- a/io_uring/opdef.c
> +++ b/io_uring/opdef.c
> @@ -495,6 +495,16 @@ const struct io_issue_def io_issue_defs[] = {
> .prep = io_ftruncate_prep,
> .issue = io_ftruncate,
> },
> + [IORING_OP_BIND] = {
> +#if defined(CONFIG_NET)
> + .needs_file = 1,
> + .prep = io_bind_prep,
> + .issue = io_bind,
> + .async_size = sizeof(struct io_async_msghdr),
> +#else
> + .prep = io_eopnotsupp_prep,
> +#endif
> + },
> };
>
> const struct io_cold_def io_cold_defs[] = {
> @@ -711,6 +721,9 @@ const struct io_cold_def io_cold_defs[] = {
> [IORING_OP_FTRUNCATE] = {
> .name = "FTRUNCATE",
> },
> + [IORING_OP_BIND] = {
> + .name = "BIND",
> + },
> };
>
> const char *io_uring_get_opcode(u8 opcode)
> --
> 2.45.2
