io_uring: Add io_uring command support for sockets

Enable io_uring commands on network sockets. Create two new
SOCKET_URING_OP commands that will operate on sockets.

In order to call ioctl on sockets, use the file_operations->io_uring_cmd
callbacks, and map it to a uring socket function, which handles the
SOCKET_URING_OP accordingly, and calls socket ioctls.

This patches was tested by creating a new test case in liburing.
Link: https://github.com/leitao/liburing/tree/io_uring_cmd

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230627134424.2784797-1-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 28 insertions, 0 deletions

diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 476c7877ce58..8e7a03c1b20e 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -7,6 +7,7 @@
 #include <linux/nospec.h>
 
 #include <uapi/linux/io_uring.h>
+#include <uapi/asm-generic/ioctls.h>
 
 #include "io_uring.h"
 #include "rsrc.h"
@@ -164,3 +165,30 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 	return io_import_fixed(rw, iter, req->imu, ubuf, len);
 }
 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
+
+int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
+{
+	struct socket *sock = cmd->file->private_data;
+	struct sock *sk = sock->sk;
+	struct proto *prot = READ_ONCE(sk->sk_prot);
+	int ret, arg = 0;
+
+	if (!prot || !prot->ioctl)
+		return -EOPNOTSUPP;
+
+	switch (cmd->sqe->cmd_op) {
+	case SOCKET_URING_OP_SIOCINQ:
+		ret = prot->ioctl(sk, SIOCINQ, &arg);
+		if (ret)
+			return ret;
+		return arg;
+	case SOCKET_URING_OP_SIOCOUTQ:
+		ret = prot->ioctl(sk, SIOCOUTQ, &arg);
+		if (ret)
+			return ret;
+		return arg;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+EXPORT_SYMBOL_GPL(io_uring_cmd_sock);