vfs_shadow_copy: handle non-existant files and wildcards

During path checking, the vfs connectpath_fn is called to
determine the share's root, relative to the file being
queried (for example, in snapshot file this may be other
than the share's "usual" root directory). connectpath_fn
must be able to answer this question even if the path does
not exist and its parent does exist. The convention in this
case is that this refers to a yet-uncreated file under the parent
and all queries are relative to the parent.

This also serves as a workaround for the case where connectpath_fn
has to handle wildcards, as with the case of SMB1 trans2 findfirst.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12172

Signed-off-by: Uri Simchoni <uri@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Thu Aug 25 05:35:29 CEST 2016 on sn-devel-144
(cherry picked from commit f41f439335efb352d03a842c370212a0af77262a)

2 files changed, 30 insertions, 3 deletions

diff --git a/selftest/knownfail b/selftest/knownfail
index 7327538e9f7..aab14564a8e 100644
--- a/selftest/knownfail
+++ b/selftest/knownfail
@@ -329,5 +329,3 @@
 ^samba4.smb2.read.access
 #ntvfs server blocks copychunk with execute access on read handle
 ^samba4.smb2.ioctl.copy_chunk_bad_access
-#new snapshot dir listing test fails on SMB1
-^samba3.blackbox.shadow_copy2(?!.*wide links).*- list directory
diff --git a/source3/modules/vfs_shadow_copy2.c b/source3/modules/vfs_shadow_copy2.c
index 61ef5d49fb0..5750b65ccae 100644
--- a/source3/modules/vfs_shadow_copy2.c
+++ b/source3/modules/vfs_shadow_copy2.c
@@ -1792,6 +1792,7 @@ static const char *shadow_copy2_connectpath(struct vfs_handle_struct *handle,
 	char *stripped = NULL;
 	char *tmp = NULL;
 	char *result = NULL;
+	char *parent_dir = NULL;
 	int saved_errno;
 	size_t rootpath_len = 0;
 
@@ -1808,7 +1809,34 @@ static const char *shadow_copy2_connectpath(struct vfs_handle_struct *handle,
 	tmp = shadow_copy2_do_convert(talloc_tos(), handle, stripped, timestamp,
 				      &rootpath_len);
 	if (tmp == NULL) {
-		goto done;
+		if (errno != ENOENT) {
+			goto done;
+		}
+
+		/*
+		 * If the converted path does not exist, and converting
+		 * the parent yields something that does exist, then
+		 * this path refers to something that has not been
+		 * created yet, relative to the parent path.
+		 * The snapshot finding is relative to the parent.
+		 * (usually snapshots are read/only but this is not
+		 * necessarily true).
+		 * This code also covers getting a wildcard in the
+		 * last component, because this function is called
+		 * prior to sanitizing the path, and in SMB1 we may
+		 * get wildcards in path names.
+		 */
+		if (!parent_dirname(talloc_tos(), stripped, &parent_dir,
+				    NULL)) {
+			errno = ENOMEM;
+			goto done;
+		}
+
+		tmp = shadow_copy2_do_convert(talloc_tos(), handle, parent_dir,
+					      timestamp, &rootpath_len);
+		if (tmp == NULL) {
+			goto done;
+		}
 	}
 
 	DBG_DEBUG("converted path is [%s] root path is [%.*s]\n", tmp,
@@ -1826,6 +1854,7 @@ done:
 	saved_errno = errno;
 	TALLOC_FREE(tmp);
 	TALLOC_FREE(stripped);
+	TALLOC_FREE(parent_dir);
 	errno = saved_errno;
 	return result;
 }