getncchanges.py: Add test for adding links during replication

We have identified a case where the Samba server can send linked
attributes but not the target object. In this case, the Samba DRS client
would hit the "Failed to re-resolve GUID" case in replmd and silently
discard the linked attribute.

However, Samba will resend the linked attribute in the next cycle
(because its USN is still higher than the committed HWM), so it should
recover OK. On older releases, this may have caused problems if the
first error resulting in a hanging link (which might mean the second
time it's processed it still fails to be added).

Signed-off-by: Tim Beale <timbeale@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>

1 files changed, 47 insertions, 0 deletions

diff --git a/source4/torture/drs/python/getncchanges.py b/source4/torture/drs/python/getncchanges.py
index c87523dcea5..65d3748834d 100644
--- a/source4/torture/drs/python/getncchanges.py
+++ b/source4/torture/drs/python/getncchanges.py
@@ -557,6 +557,53 @@ class DrsReplicaSyncIntegrityTestCase(drs_base.DrsBaseTestCase):
         # Check we received links for all the reportees
         self.assert_expected_links(expected_links)
 
+    def test_repl_integrity_link_attr(self):
+        """
+        Tests adding links to new objects while a replication is in progress.
+        """
+
+        # create some source objects for the linked attributes, sandwiched
+        # between 2 blocks of filler objects
+        filler = self.create_object_range(0, 100, prefix="filler")
+        reportees = self.create_object_range(0, 100, prefix="reportee")
+        filler += self.create_object_range(100, 200, prefix="filler")
+
+        # Start the replication and get the first block of filler objects
+        # (We're being mean here and setting the GET_TGT flag right from the
+        # start. On earlier Samba versions, if the client encountered an
+        # unknown target object and retried with GET_TGT, it would restart the
+        # replication cycle from scratch, which avoids the problem).
+        self.repl_get_next(get_tgt=True)
+
+        # create the target objects and add the links. These objects should be
+        # outside the scope of the Samba replication cycle, but the links should
+        # still get sent with the source object
+        managers = self.create_object_range(0, 100, prefix="manager")
+
+        for i in range(0, 100):
+            self.modify_object(reportees[i], "managedBy", managers[i])
+
+        expected_objects = managers + reportees + filler
+        expected_links = reportees
+
+        # complete the replication
+        while not self.replication_complete():
+            self.repl_get_next(get_tgt=True)
+
+        # If we didn't receive the most recently created objects in the last
+        # replication cycle, then kick off another replication to get them
+        if len(self.rxd_dn_list) < len(expected_objects):
+            self.repl_get_next()
+
+            while not self.replication_complete():
+                self.repl_get_next()
+
+        # Check we get all the objects we're expecting
+        self.assert_expected_data(expected_objects)
+
+        # Check we received links for all the parents
+        self.assert_expected_links(expected_links)
+
     def test_repl_get_anc_link_attr(self):
         """
         A basic GET_ANC test where the parents have linked attributes