[PATCH] vfs: propagate snapshot enumeration permissions errors

[David Disseldorp]

The current FSCTL_GET_SHADOW_COPY_DATA/FSCTL_SRV_ENUMERATE_SNAPSHOTS
handler squashes all non-ENOSYS errors into an NT_STATUS_UNSUCCESSFUL
response.
This commit ensures that permissions errors are propagated up to the
client as NT_STATUS_ACCESS_DENIED, to aid debugging.
The Windows Explorer "Previous Versions" dialogue doesn't appear to
distinguish between error codes. It displays "There are no previous
versions available" in both cases.

Signed-off-by: David Disseldorp <ddiss at samba.org>
---
 source3/modules/vfs_default.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/source3/modules/vfs_default.c b/source3/modules/vfs_default.c
index 0b7de27..77b1bed 100644
--- a/source3/modules/vfs_default.c
+++ b/source3/modules/vfs_default.c
@@ -1078,12 +1078,12 @@ static NTSTATUS vfswrap_fsctl(struct vfs_handle_struct *handle,
 {
 	const char *in_data = (const char *)_in_data;
 	char **out_data = (char **)_out_data;
+	NTSTATUS status;
 
 	switch (function) {
 	case FSCTL_SET_SPARSE:
 	{
 		bool set_sparse = true;
-		NTSTATUS status;
 
 		if (in_len >= 1 && in_data[0] == 0) {
 			set_sparse = false;
@@ -1182,16 +1182,21 @@ static NTSTATUS vfswrap_fsctl(struct vfs_handle_struct *handle,
 		 * Call the VFS routine to actually do the work.
 		 */
 		if (SMB_VFS_GET_SHADOW_COPY_DATA(fsp, shadow_data, labels)!=0) {
-			TALLOC_FREE(shadow_data);
+			int log_lev = 0;
 			if (errno == ENOSYS) {
-				DEBUG(5,("FSCTL_GET_SHADOW_COPY_DATA: connectpath %s, not supported.\n",
-					fsp->conn->connectpath));
-				return NT_STATUS_NOT_SUPPORTED;
+				log_lev = 5;
+				status = NT_STATUS_NOT_SUPPORTED;
+			} else if ((errno == EPERM) || (errno == EACCES)) {
+				status = NT_STATUS_ACCESS_DENIED;
 			} else {
-				DEBUG(0,("FSCTL_GET_SHADOW_COPY_DATA: connectpath %s, failed.\n",
-					fsp->conn->connectpath));
-				return NT_STATUS_UNSUCCESSFUL;
+				status = NT_STATUS_UNSUCCESSFUL;
 			}
+			DEBUG(log_lev, ("FSCTL_GET_SHADOW_COPY_DATA: "
+					"connectpath %s, failed - %s.\n",
+					fsp->conn->connectpath,
+					nt_errstr(status)));
+			TALLOC_FREE(shadow_data);
+			return status;
 		}
 
 		labels_data_count = (shadow_data->num_volumes * 2 *
@@ -1319,7 +1324,6 @@ static NTSTATUS vfswrap_fsctl(struct vfs_handle_struct *handle,
 		 * and SEEK_DATA/SEEK_HOLE on Solaris is needed to make
 		 * this FSCTL correct for sparse files.
 		 */
-		NTSTATUS status;
 		uint64_t offset, length;
 		char *out_data_tmp = NULL;
 
-- 
1.8.4.5