libsmb2: Fix opening the rootdirectory, part 1

[MS-SMB2], 2.2.13 says: In the request, the Buffer field MUST be at least one
byte in length. Implement that for the 0-length filename without create blobs.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/source4/libcli/smb2/create.c b/source4/libcli/smb2/create.c
index 1a7f02b0703..10fe4f7ce32 100644
--- a/source4/libcli/smb2/create.c
+++ b/source4/libcli/smb2/create.c
@@ -294,6 +294,21 @@ struct smb2_request *smb2_create_send(struct smb2_tree *tree, struct smb2_create
 		return NULL;
 	}
 
+	if (((io->in.fname == NULL) || (strlen(io->in.fname) == 0)) &&
+	    (blob.length == 0)) {
+		struct smb2_request_buffer *buf = &req->out;
+
+		status = smb2_grow_buffer(buf, 1);
+		if (!NT_STATUS_IS_OK(status)) {
+			talloc_free(req);
+			return NULL;
+		}
+		buf->dynamic[0] = 0;
+		buf->dynamic += 1;
+		buf->body_size += 1;
+		buf->size += 1;
+	}
+
 	data_blob_free(&blob);
 
 	smb2_transport_send(req);