2023-09-13 15:30:22

by Breno Leitao

Subject: [PATCH v6 7/8] io_uring/cmd: Introduce SOCKET_URING_OP_SETSOCKOPT

Add support for SOCKET_URING_OP_SETSOCKOPT. This new command is similar
to setsockopt(2). This implementation leverages the function
do_sock_setsockopt(), which is shared with the setsockopt() system call
path.

Important to say that userspace needs to keep the pointer's memory alive
until the operation is completed. I.e, the memory could not be
deallocated before the CQE is returned to userspace.

Reviewed-by: Gabriel Krisman Bertazi <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
---
include/uapi/linux/io_uring.h | 1 +
io_uring/uring_cmd.c | 16 ++++++++++++++++
2 files changed, 17 insertions(+)

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 1c789ee6462d..99cdb2c1e240 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -743,6 +743,7 @@ enum {
SOCKET_URING_OP_SIOCINQ = 0,
SOCKET_URING_OP_SIOCOUTQ,
SOCKET_URING_OP_GETSOCKOPT,
+ SOCKET_URING_OP_SETSOCKOPT,
};

#ifdef __cplusplus
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index a2a6ac0c503b..2266c829d1c4 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -180,6 +180,20 @@ static inline int io_uring_cmd_getsockopt(struct socket *sock,
return do_sock_getsockopt(sock, compat, level, optname, optval, optlen);
}

+static inline int io_uring_cmd_setsockopt(struct socket *sock,
+ struct io_uring_cmd *cmd,
+ unsigned int issue_flags)
+{
+ void __user *optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
+ int optlen = READ_ONCE(cmd->sqe->optlen);
+ bool compat = !!(issue_flags & IO_URING_F_COMPAT);
+ int optname = READ_ONCE(cmd->sqe->optname);
+ int level = READ_ONCE(cmd->sqe->level);
+
+ return do_sock_setsockopt(sock, compat, level, optname, optval,
+ optlen);
+}
+
#if defined(CONFIG_NET)
int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
{
@@ -204,6 +218,8 @@ int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
return arg;
case SOCKET_URING_OP_GETSOCKOPT:
return io_uring_cmd_getsockopt(sock, cmd, issue_flags);
+ case SOCKET_URING_OP_SETSOCKOPT:
+ return io_uring_cmd_setsockopt(sock, cmd, issue_flags);
default:
return -EOPNOTSUPP;
}
--
2.34.1

2023-09-13 23:17:16

by Jens Axboe

Subject: Re: [PATCH v6 7/8] io_uring/cmd: Introduce SOCKET_URING_OP_SETSOCKOPT

On 9/13/23 9:27 AM, Breno Leitao wrote:
> Add support for SOCKET_URING_OP_SETSOCKOPT. This new command is similar
> to setsockopt(2). This implementation leverages the function
> do_sock_setsockopt(), which is shared with the setsockopt() system call
> path.
>
> Important to say that userspace needs to keep the pointer's memory alive
> until the operation is completed. I.e, the memory could not be
> deallocated before the CQE is returned to userspace.

This is different than other commands that write data. Since
IORING_FEAT_SUBMIT_STABLE was introduced, any command that writes data
should ensure that this data is stable. Eg it follows the life time of
the SQE, and doesn't need to be available until a CQE has been posted
for it. This is _generally_ true, even if we do have a few exceptions.

The problem is that then you cannot use user pointers, obviously, you'd
need to be able to pass in the value directly to do_sock_setsockopt()...

--
Jens Axboe