[PATCH] lib/ldb minor fixes

[Kamen Mazdrashki]

Hi,

Attached is a small set of patches for lib/ldb handling for
parameters and error handling for Python-related code.
I have hit those problems while writing some python test
without copy&paste prviously working code :)

Review&push will be appreciated

Cheers,
Kamen
-------------- next part --------------
From 2655d13adae82d7a1f1c29ce0c22d216673c9b60 Mon Sep 17 00:00:00 2001
From: Kamen Mazdrashki <kamenim at samba.org>
Date: Sun, 9 Nov 2014 04:28:47 +0100
Subject: [PATCH 1/5] lib-pyldb: Avoid SEGFAUL in case we can't convert passed
 valud to py-String

Signed-off-by: Kamen Mazdrashki <kamenim at samba.org>
---
 lib/ldb/pyldb.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/ldb/pyldb.c b/lib/ldb/pyldb.c
index 78b8012..c541b72 100644
--- a/lib/ldb/pyldb.c
+++ b/lib/ldb/pyldb.c
@@ -1629,6 +1629,11 @@ static PyObject *py_ldb_schema_format_value(PyLdbObject *self, PyObject *args)
 	old_val.data = (uint8_t *)PyString_AsString(val);
 	old_val.length = PyString_Size(val);
 
+	if (old_val.data == NULL) {
+		PyErr_SetString(PyExc_RuntimeError, "Failed to convert passed value to String");
+		return NULL;
+	}
+
 	a = ldb_schema_attribute_by_name(pyldb_Ldb_AsLdbContext(self), element_name);
 
 	if (a == NULL) {
-- 
1.9.1


From b1964a61f69aa4eb6f67c1d2458d4abd5c8e4df9 Mon Sep 17 00:00:00 2001
From: Kamen Mazdrashki <kamenim at samba.org>
Date: Sun, 9 Nov 2014 04:31:36 +0100
Subject: [PATCH 2/5] lib-pyldb: Avoid leaking memory in error cases

Signed-off-by: Kamen Mazdrashki <kamenim at samba.org>
---
 lib/ldb/pyldb.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/ldb/pyldb.c b/lib/ldb/pyldb.c
index c541b72..efac7b1 100644
--- a/lib/ldb/pyldb.c
+++ b/lib/ldb/pyldb.c
@@ -1624,8 +1624,6 @@ static PyObject *py_ldb_schema_format_value(PyLdbObject *self, PyObject *args)
 	if (!PyArg_ParseTuple(args, "sO", &element_name, &val))
 		return NULL;
 
-	mem_ctx = talloc_new(NULL);
-
 	old_val.data = (uint8_t *)PyString_AsString(val);
 	old_val.length = PyString_Size(val);
 
@@ -1640,6 +1638,12 @@ static PyObject *py_ldb_schema_format_value(PyLdbObject *self, PyObject *args)
 		Py_RETURN_NONE;
 	}
 
+	mem_ctx = talloc_new(NULL);
+	if (mem_ctx == NULL) {
+		PyErr_NoMemory();
+		return NULL;
+	}
+
 	if (a->syntax->ldif_write_fn(pyldb_Ldb_AsLdbContext(self), mem_ctx, &old_val, &new_val) != 0) {
 		talloc_free(mem_ctx);
 		Py_RETURN_NONE;
-- 
1.9.1


From fc1134c05a9e183bed07929835bfcef2ba8496d5 Mon Sep 17 00:00:00 2001
From: Kamen Mazdrashki <kamenim at samba.org>
Date: Mon, 10 Nov 2014 22:59:07 +0100
Subject: [PATCH 3/5] lib-pyldb: Throw exception when we can't create
 MessageElement object

At the moment we return an error, but no exception and it is
hard to instantly see what the problem is from Python

Signed-off-by: Kamen Mazdrashki <kamenim at samba.org>
---
 lib/ldb/pyldb.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/ldb/pyldb.c b/lib/ldb/pyldb.c
index efac7b1..40c802f 100644
--- a/lib/ldb/pyldb.c
+++ b/lib/ldb/pyldb.c
@@ -2352,6 +2352,8 @@ static struct ldb_message_element *PyObject_AsMessageElement(
 				(uint8_t *)PyString_AsString(obj), me->values[i].length+1);
 		}
 	} else {
+		PyErr_Format(PyExc_TypeError,
+			     "String or List type expected for '%s' attribute", attr_name);
 		talloc_free(me);
 		me = NULL;
 	}
-- 
1.9.1


From f69a5f6618f64d6c6b584d90bfe1d61a62970deb Mon Sep 17 00:00:00 2001
From: Kamen Mazdrashki <kamenim at samba.org>
Date: Tue, 11 Nov 2014 02:56:32 +0100
Subject: [PATCH 4/5] lib-ldb: Check for input parameter when searching
 attributes by name

This prevents a segfault that is hard to be tracked down from
Python bindings

Signed-off-by: Kamen Mazdrashki <kamenim at samba.org>
---
 lib/ldb/common/ldb_attributes.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/ldb/common/ldb_attributes.c b/lib/ldb/common/ldb_attributes.c
index 21a3e6e..4132bc9 100644
--- a/lib/ldb/common/ldb_attributes.c
+++ b/lib/ldb/common/ldb_attributes.c
@@ -127,6 +127,11 @@ static const struct ldb_schema_attribute *ldb_schema_attribute_by_name_internal(
 	int r;
 	const struct ldb_schema_attribute *def = &ldb_attribute_default;
 
+	/* attribute name must be valid pointer */
+	if (name == NULL) {
+		return NULL;
+	}
+
 	/* as handlers are sorted, '*' must be the first if present */
 	if (strcmp(ldb->schema.attributes[0].name, "*") == 0) {
 		def = &ldb->schema.attributes[0];
-- 
1.9.1


From 11dd79e532a773d77a418e135830eb1aa011d692 Mon Sep 17 00:00:00 2001
From: Kamen Mazdrashki <kamenim at samba.org>
Date: Tue, 11 Nov 2014 02:57:50 +0100
Subject: [PATCH 5/5] lib-ldb_ldif: Stop processing if we can't resolve
 ldb_message element name

This also prevent a segfault when using Python binding

Signed-off-by: Kamen Mazdrashki <kamenim at samba.org>
---
 lib/ldb/common/ldb_ldif.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/ldb/common/ldb_ldif.c b/lib/ldb/common/ldb_ldif.c
index a2e4488..eb8179a 100644
--- a/lib/ldb/common/ldb_ldif.c
+++ b/lib/ldb/common/ldb_ldif.c
@@ -313,6 +313,13 @@ static int ldb_ldif_write_trace(struct ldb_context *ldb,
 		const struct ldb_schema_attribute *a;
 
 		a = ldb_schema_attribute_by_name(ldb, msg->elements[i].name);
+		if (a == NULL || a->name == NULL) {
+			ldb_debug(ldb, LDB_DEBUG_ERROR, "Error: ldb_schema_attribute_by_name() "
+					"failed for Message element at %d with name %s.",
+					i, msg->elements[i].name);
+			talloc_free(mem_ctx);
+			return -1;
+		}
 
 		if (ldif->changetype == LDB_CHANGETYPE_MODIFY) {
 			switch (msg->elements[i].flags & LDB_FLAG_MOD_MASK) {
-- 
1.9.1