lib/smbconf: expose smbconf error codes to python wrapper

The smbconf library defines an enum of error codes that can be returned
from the C calls. The error codes were getting stored in the python
SMBConfError type but it was not easy to access or obvious what the
integer code represented.

This change makes it easier to get the returned error code: via a
`error_code` attribute on the exception value. It also exposes the
integer constants to the module. Simple tests for a few of the more
obvious error codes check that this new error handling correctly
exposes the error code values.

Signed-off-by: John Mulligan <jmulligan@redhat.com>
Reviewed-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>

Autobuild-User(master): Günther Deschner <gd@samba.org>
Autobuild-Date(master): Wed Jun  8 13:13:10 UTC 2022 on sn-devel-184

1 files changed, 34 insertions, 5 deletions

diff --git a/lib/smbconf/pysmbconf.c b/lib/smbconf/pysmbconf.c
index b0aca4508af..1b3c101005a 100644
--- a/lib/smbconf/pysmbconf.c
+++ b/lib/smbconf/pysmbconf.c
@@ -35,7 +35,6 @@ static void py_raise_SMBConfError(sbcErr err)
 
 	/*
 	 * TODO: have the exception type accept arguments in new/init
-	 * and make the error value accessible as a property
 	 */
 	args = Py_BuildValue("(is)", err, sbcErrorString(err));
 	if (args == NULL) {
@@ -44,11 +43,22 @@ static void py_raise_SMBConfError(sbcErr err)
 		return;
 	}
 	v = PyObject_Call(PyExc_SMBConfError, args, NULL);
-	Py_DECREF(args);
-	if (v != NULL) {
-		PyErr_SetObject((PyObject *) Py_TYPE(v), v);
-		Py_DECREF(v);
+	if (v == NULL) {
+		Py_CLEAR(args);
+		return;
+	}
+	/*
+	 * It's clearer to set an explicit error_code attribute for use in calling
+	 * code to check what kind of SMBConfError was raised.
+	 */
+	if (PyObject_SetAttrString(v, "error_code", PyTuple_GetItem(args, 0)) == -1) {
+		Py_CLEAR(v);
+		Py_CLEAR(args);
+		return;
 	}
+	Py_CLEAR(args);
+	PyErr_SetObject((PyObject *) Py_TYPE(v), v);
+	Py_DECREF(v);
 }
 
 /*
@@ -780,5 +790,24 @@ MODULE_INIT_FUNC(smbconf)
 		return NULL;
 	}
 
+/*
+ * ADD_FLAGS macro borrowed from source3/libsmb/pylibsmb.c
+ */
+#define ADD_FLAGS(val)	PyModule_AddObject(m, #val, PyLong_FromLong(val))
+
+	ADD_FLAGS(SBC_ERR_OK);
+	ADD_FLAGS(SBC_ERR_NOT_IMPLEMENTED);
+	ADD_FLAGS(SBC_ERR_NOT_SUPPORTED);
+	ADD_FLAGS(SBC_ERR_UNKNOWN_FAILURE);
+	ADD_FLAGS(SBC_ERR_NOMEM);
+	ADD_FLAGS(SBC_ERR_INVALID_PARAM);
+	ADD_FLAGS(SBC_ERR_BADFILE);
+	ADD_FLAGS(SBC_ERR_NO_SUCH_SERVICE);
+	ADD_FLAGS(SBC_ERR_IO_FAILURE);
+	ADD_FLAGS(SBC_ERR_CAN_NOT_COMPLETE);
+	ADD_FLAGS(SBC_ERR_NO_MORE_ITEMS);
+	ADD_FLAGS(SBC_ERR_FILE_EXISTS);
+	ADD_FLAGS(SBC_ERR_ACCESS_DENIED);
+
 	return m;
 }