ksmbd: add support for negotiating signing algorithm

Support for faster packet signing (using GMAC instead of CMAC) can
now be negotiated to some newer servers, including Windows.
See MS-SMB2 section 2.2.3.17.

This patch adds support for sending the new negotiate context with two
supported signing algorithms(AES-CMAC, HMAC-SHA256).
If client add support for AES_GMAC, Server will be supported later
depend on it.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/ksmbd/connection.h b/fs/ksmbd/connection.h
index 487c202..e5403c5 100644
--- a/fs/ksmbd/connection.h
+++ b/fs/ksmbd/connection.h
@@ -109,6 +109,8 @@ struct ksmbd_conn {
 	__le16				cipher_type;
 	__le16				compress_algorithm;
 	bool				posix_ext_supported;
+	bool				signing_negotiated;
+	__le16				signing_algorithm;
 	bool				binding;
 };