[PATCH] nfs4acl: Fix owner mapping with ID_TYPE_BOTH

[Christof Schmitt]

From f1883adf6ed027a03be2a3d4f1631d8bdb283e38 Mon Sep 17 00:00:00 2001
From: Christof Schmitt <cs at samba.org>
Date: Mon, 12 Sep 2016 16:22:16 -0700
Subject: [PATCH] nfs4acl: Fix owner mapping with ID_TYPE_BOTH

This fixes a corner case when using NFS4 ACLs with ID_TYPE_BOTH.  Before
this patch, the owner entry in the ACL would be mapped to a gid entry in
the NFSv4 ACL, and not the expected special owner entry. This is caused
by the id mapping returning a valid gid and the nfs4 mapping assumed
that this was actually a group.

Fix this by asking for the uid first, and explicitly checking if the
mapped uid matches the owner. That creates a uid entry in the NFSv4 ACL
that can be changed later in smbacl4_substitute_{simple,special} to the
expected special owner entry.

Signed-off-by: Christof Schmitt <cs at samba.org>
---
 source3/modules/nfs4_acls.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/source3/modules/nfs4_acls.c b/source3/modules/nfs4_acls.c
index 71f4d8d..996dbab 100644
--- a/source3/modules/nfs4_acls.c
+++ b/source3/modules/nfs4_acls.c
@@ -715,11 +715,16 @@ static bool smbacl4_fill_ace4(
 		uid_t uid;
 		gid_t gid;
 
-		if (sid_to_gid(&ace_nt->trustee, &gid)) {
+		/*
+		 * ID_TYPE_BOTH returns both uid and gid. Explicitly
+		 * check for ownerUID to allow the mapping of the
+		 * owner to a special entry in this idmap config.
+		 */
+		if (sid_to_uid(&ace_nt->trustee, &uid) && uid == ownerUID) {
+			ace_v4->who.uid = uid;
+		} else if (sid_to_gid(&ace_nt->trustee, &gid)) {
 			ace_v4->aceFlags |= SMB_ACE4_IDENTIFIER_GROUP;
 			ace_v4->who.gid = gid;
-		} else if (sid_to_uid(&ace_nt->trustee, &uid)) {
-			ace_v4->who.uid = uid;
 		} else if (dom_sid_compare_domain(&ace_nt->trustee,
 						  &global_sid_Unix_NFS) == 0) {
 			return false;
-- 
1.8.3.1