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

[Breno Leitao <leitao@debian.org>]

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 <krisman@suse.de>
Signed-off-by: Breno Leitao <leitao@debian.org>
---
 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