pydsdb: added get_backlink_from_lDAPDisplayName()

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>
Pair-Programmed-With: Amitay Isaacs <amitay@gmail.com>

2 files changed, 50 insertions, 0 deletions

diff --git a/source4/dsdb/pydsdb.c b/source4/dsdb/pydsdb.c
index 463a2f99d9..e74f2bb584 100644
--- a/source4/dsdb/pydsdb.c
+++ b/source4/dsdb/pydsdb.c
@@ -394,6 +394,49 @@ static PyObject *py_dsdb_get_linkId_from_lDAPDisplayName(PyObject *self, PyObjec
 	return PyInt_FromLong(attribute->linkID);
 }
 
+/*
+  return the backlink attribute name (if any) for an attribute
+ */
+static PyObject *py_dsdb_get_backlink_from_lDAPDisplayName(PyObject *self, PyObject *args)
+{
+	PyObject *py_ldb;
+	struct ldb_context *ldb;
+	struct dsdb_schema *schema;
+	const char *ldap_display_name;
+	const struct dsdb_attribute *attribute, *target_attr;
+
+	if (!PyArg_ParseTuple(args, "Os", &py_ldb, &ldap_display_name))
+		return NULL;
+
+	PyErr_LDB_OR_RAISE(py_ldb, ldb);
+
+	schema = dsdb_get_schema(ldb, NULL);
+
+	if (!schema) {
+		PyErr_SetString(PyExc_RuntimeError, "Failed to find a schema from ldb");
+		return NULL;
+	}
+
+	attribute = dsdb_attribute_by_lDAPDisplayName(schema, ldap_display_name);
+	if (attribute == NULL) {
+		PyErr_Format(PyExc_RuntimeError, "Failed to find attribute '%s'", ldap_display_name);
+		return NULL;
+	}
+
+	if (attribute->linkID == 0) {
+		Py_RETURN_NONE;
+	}
+
+	target_attr = dsdb_attribute_by_linkID(schema, attribute->linkID ^ 1);
+	if (target_attr == NULL) {
+		/* when we add pseudo-backlinks we'll need to handle
+		   them here */
+		Py_RETURN_NONE;
+	}
+
+	return PyString_FromString(target_attr->lDAPDisplayName);
+}
+
 
 static PyObject *py_dsdb_get_lDAPDisplayName_by_attid(PyObject *self, PyObject *args)
 {
@@ -937,6 +980,8 @@ static PyMethodDef py_dsdb_methods[] = {
 		METH_VARARGS, NULL },
 	{ "_dsdb_get_lDAPDisplayName_by_attid", (PyCFunction)py_dsdb_get_lDAPDisplayName_by_attid,
 		METH_VARARGS, NULL },
+	{ "_dsdb_get_backlink_from_lDAPDisplayName", (PyCFunction)py_dsdb_get_backlink_from_lDAPDisplayName,
+		METH_VARARGS, NULL },
 	{ "_dsdb_set_ntds_invocation_id",
 		(PyCFunction)py_dsdb_set_ntds_invocation_id, METH_VARARGS,
 		NULL },
diff --git a/source4/scripting/python/samba/samdb.py b/source4/scripting/python/samba/samdb.py
index f77ce1737d..a7ed1d2c39 100644
--- a/source4/scripting/python/samba/samdb.py
+++ b/source4/scripting/python/samba/samdb.py
@@ -521,6 +521,11 @@ accountExpires: %u
         '''return the lDAPDisplayName from an integer DRS attribute ID'''
         return dsdb._dsdb_get_lDAPDisplayName_by_attid(self, attid)
 
+    def get_backlink_from_lDAPDisplayName(self, ldap_display_name):
+        '''return the attribute name of the corresponding backlink from the name
+        of a forward link attribute. If there is no backlink return None'''
+        return dsdb._dsdb_get_backlink_from_lDAPDisplayName(self, ldap_display_name)
+
     def set_ntds_settings_dn(self, ntds_settings_dn):
         """Set the NTDS Settings DN, as would be returned on the dsServiceName
         rootDSE attribute.