From: Ralph Boehme <slow@samba.org>
Date: Sat, 20 Oct 2018 12:53:50 +0000 (+0200)
Subject: vfs_fruit: filter empty streams
X-Git-Tag: samba-4.8.8~56
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=280722734964afa847280851f6d493e2f987f060;p=thirdparty%2Fsamba.git

vfs_fruit: filter empty streams

First step in achieving macOS compliant behaviour wrt to empty streams:
- hide empty streams in streaminfo
- prevent opens of empty streams

This means that we may carry 0-byte sized streams in our streams
backend, but this shouldn't really hurt.

The previous attempt of deleting the streams when an SMB setinfo eof to
0 request came in, turned out be a road into desaster.

We could set delete-on-close on the stream, but that means we'd have to
check for it for every write on a stream and checking the
delete-on-close bits requires fetching the locking.tdb record, so this
is expensive and I'd like to avoid that overhead.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=13646

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
(cherry picked from commit ebfcf75e993b1a792db76b94aa898532e1c81eeb)
---

diff --git a/selftest/knownfail.d/samba3.vfs.fruit b/selftest/knownfail.d/samba3.vfs.fruit
index 5ecba522d4a..6307e2b3404 100644
--- a/selftest/knownfail.d/samba3.vfs.fruit
+++ b/selftest/knownfail.d/samba3.vfs.fruit
@@ -1,5 +1,2 @@
 ^samba3.vfs.fruit streams_depot.OS X AppleDouble file conversion\(nt4_dc\)
 ^samba3.vfs.fruit streams_depot.OS X AppleDouble file conversion without embedded xattr\(nt4_dc\)
-^samba3.vfs.fruit metadata_netatalk.setinfo eof stream\(nt4_dc\)
-^samba3.vfs.fruit metadata_stream.setinfo eof stream\(nt4_dc\)
-^samba3.vfs.fruit streams_depot.setinfo eof stream\(nt4_dc\)
diff --git a/source3/modules/vfs_fruit.c b/source3/modules/vfs_fruit.c
index a36e131be30..9932249e315 100644
--- a/source3/modules/vfs_fruit.c
+++ b/source3/modules/vfs_fruit.c
@@ -5578,6 +5578,36 @@ static NTSTATUS fruit_streaminfo_rsrc(vfs_handle_struct *handle,
 	return status;
 }
 
+static void fruit_filter_empty_streams(unsigned int *pnum_streams,
+				       struct stream_struct **pstreams)
+{
+	unsigned num_streams = *pnum_streams;
+	struct stream_struct *streams = *pstreams;
+	unsigned i = 0;
+
+	if (!global_fruit_config.nego_aapl) {
+		return;
+	}
+
+	while (i < num_streams) {
+		struct smb_filename smb_fname = (struct smb_filename) {
+			.stream_name = streams[i].name,
+		};
+
+		if (is_ntfs_default_stream_smb_fname(&smb_fname)
+		    || streams[i].size > 0)
+		{
+			i++;
+			continue;
+		}
+
+		streams[i] = streams[num_streams - 1];
+		num_streams--;
+	}
+
+	*pnum_streams = num_streams;
+}
+
 static NTSTATUS fruit_streaminfo(vfs_handle_struct *handle,
 				 struct files_struct *fsp,
 				 const struct smb_filename *smb_fname,
@@ -5599,6 +5629,8 @@ static NTSTATUS fruit_streaminfo(vfs_handle_struct *handle,
 		return status;
 	}
 
+	fruit_filter_empty_streams(pnum_streams, pstreams);
+
 	status = fruit_streaminfo_meta(handle, fsp, smb_fname,
 				       mem_ctx, pnum_streams, pstreams);
 	if (!NT_STATUS_IS_OK(status)) {
@@ -5868,13 +5900,13 @@ static NTSTATUS fruit_create_file(vfs_handle_struct *handle,
 	 * Cf the vfs_fruit torture tests in test_rfork_create().
 	 */
 	if (global_fruit_config.nego_aapl &&
-	    is_afpresource_stream(fsp->fsp_name) &&
-	    create_disposition == FILE_OPEN)
+	    create_disposition == FILE_OPEN &&
+	    smb_fname->st.st_ex_size == 0 &&
+	    is_ntfs_stream_smb_fname(smb_fname) &&
+	    !(is_ntfs_default_stream_smb_fname(smb_fname)))
 	{
-		if (fsp->fsp_name->st.st_ex_size == 0) {
-			status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
-			goto fail;
-		}
+		status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
+		goto fail;
 	}
 
 	if (is_ntfs_stream_smb_fname(smb_fname)