Commit a5d2f99a authored by Breno Leitao's avatar Breno Leitao Committed by Jens Axboe
Browse files

io_uring/cmd: Introduce SOCKET_URING_OP_GETSOCKOPT 



Add support for getsockopt command (SOCKET_URING_OP_GETSOCKOPT), where
level is SOL_SOCKET. This is leveraging the sockptr_t infrastructure,
where a sockptr_t is either userspace or kernel space, and handled as
such.

Differently from the getsockopt(2), the optlen field is not a userspace
pointers. In getsockopt(2), userspace provides optlen pointer, which is
overwritten by the kernel.  In this implementation, userspace passes a
u32, and the new value is returned in cqe->res. I.e., optlen is not a
pointer.

Important to say that userspace needs to keep the pointer alive until
the CQE is completed.

Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
Reviewed-by: default avatarGabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20231016134750.1381153-10-leitao@debian.org


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent d2cac3ec

include/uapi/linux/io_uring.h

+7 −0
Original line number Diff line number Diff line
@@ -43,6 +43,10 @@ struct io_uring_sqe { 
	union {

		__u64	addr;	/* pointer to buffer or iovecs */

		__u64	splice_off_in;

		struct {

			__u32	level;

			__u32	optname;

		};

	};

	__u32	len;		/* buffer size or number of iovecs */

	union {
@@ -80,6 +84,7 @@ struct io_uring_sqe { 
	union {

		__s32	splice_fd_in;

		__u32	file_index;

		__u32	optlen;

		struct {

			__u16	addr_len;

			__u16	__pad3[1];
@@ -90,6 +95,7 @@ struct io_uring_sqe { 
			__u64	addr3;

			__u64	__pad2[1];

		};

		__u64	optval;

		/*

		 * If the ring is initialized with IORING_SETUP_SQE128, then

		 * this field is used for 80 bytes of arbitrary command data
@@ -736,6 +742,7 @@ struct io_uring_recvmsg_out { 
enum {

	SOCKET_URING_OP_SIOCINQ		= 0,

	SOCKET_URING_OP_SIOCOUTQ,

	SOCKET_URING_OP_GETSOCKOPT,

};



#ifdef __cplusplus

io_uring/uring_cmd.c

+28 −0
Original line number Diff line number Diff line
@@ -214,6 +214,32 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw, 
}

EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);



static inline int io_uring_cmd_getsockopt(struct socket *sock,

					  struct io_uring_cmd *cmd,

					  unsigned int issue_flags)

{

	bool compat = !!(issue_flags & IO_URING_F_COMPAT);

	int optlen, optname, level, err;

	void __user *optval;



	level = READ_ONCE(cmd->sqe->level);

	if (level != SOL_SOCKET)

		return -EOPNOTSUPP;



	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));

	optname = READ_ONCE(cmd->sqe->optname);

	optlen = READ_ONCE(cmd->sqe->optlen);



	err = do_sock_getsockopt(sock, compat, level, optname,

				 USER_SOCKPTR(optval),

				 KERNEL_SOCKPTR(&optlen));

	if (err)

		return err;



	/* On success, return optlen */

	return optlen;

}



#if defined(CONFIG_NET)

int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)

{
@@ -236,6 +262,8 @@ int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) 
		if (ret)

			return ret;

		return arg;

	case SOCKET_URING_OP_GETSOCKOPT:

		return io_uring_cmd_getsockopt(sock, cmd, issue_flags);

	default:

		return -EOPNOTSUPP;

	}