vfs_nfs4acl_xattr: implement take-ownership as in vfs_acl_common

This allows take-ownership to work if the user has SEC_STD_WRITE_OWNER.

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

diff --git a/source3/modules/vfs_nfs4acl_xattr.c b/source3/modules/vfs_nfs4acl_xattr.c
index 9c0c87f6331d450e36715f3939daef9eb45b5e48..d4f4d47635ee143779ae04423268676eff6567e6 100644 (file)
--- a/source3/modules/vfs_nfs4acl_xattr.c
+++ b/source3/modules/vfs_nfs4acl_xattr.c
@@ -359,9 +359,11 @@ static NTSTATUS nfs4acl_xattr_fset_nt_acl(vfs_handle_struct *handle,
                         const struct security_descriptor *psd)
 {
        struct nfs4acl_config *config = NULL;
+       const struct security_token *token = NULL;
        mode_t existing_mode;
        mode_t expected_mode;
        mode_t restored_mode;
+       bool chown_needed = false;
        NTSTATUS status;
        int ret;
 
@@ -416,11 +418,58 @@ static NTSTATUS nfs4acl_xattr_fset_nt_acl(vfs_handle_struct *handle,
                                     security_info_sent,
                                     psd,
                                     nfs4acl_smb4acl_set_fn);
-       if (!NT_STATUS_IS_OK(status)) {
-               return status;
+       if (NT_STATUS_IS_OK(status)) {
+               return NT_STATUS_OK;
        }
 
-       return NT_STATUS_OK;
+       /*
+        * We got access denied. If we're already root, or we didn't
+        * need to do a chown, or the fsp isn't open with WRITE_OWNER
+        * access, just return.
+        */
+
+       if ((security_info_sent & SECINFO_OWNER) &&
+           (psd->owner_sid != NULL))
+       {
+               chown_needed = true;
+       }
+       if ((security_info_sent & SECINFO_GROUP) &&
+           (psd->group_sid != NULL))
+       {
+               chown_needed = true;
+       }
+
+       if (get_current_uid(handle->conn) == 0 ||
+           chown_needed == false ||
+           !(fsp->access_mask & SEC_STD_WRITE_OWNER))
+       {
+               return NT_STATUS_ACCESS_DENIED;
+       }
+
+       /*
+        * Only allow take-ownership, not give-ownership. That's the way Windows
+        * implements SEC_STD_WRITE_OWNER. MS-FSA 2.1.5.16 just states: If
+        * InputBuffer.OwnerSid is not a valid owner SID for a file in the
+        * objectstore, as determined in an implementation specific manner, the
+        * object store MUST return STATUS_INVALID_OWNER.
+        */
+       token = get_current_nttok(fsp->conn);
+       if (!security_token_is_sid(token, psd->owner_sid)) {
+               return NT_STATUS_INVALID_OWNER;
+       }
+
+       DBG_DEBUG("overriding chown on file %s for sid %s\n",
+                 fsp_str_dbg(fsp), sid_string_tos(psd->owner_sid));
+
+       become_root();
+       status = smb_set_nt_acl_nfs4(handle,
+                                    fsp,
+                                    &config->nfs4_params,
+                                    security_info_sent,
+                                    psd,
+                                    nfs4acl_smb4acl_set_fn);
+       unbecome_root();
+       return status;
 }
 
 static int nfs4acl_connect(struct vfs_handle_struct *handle,