pidl/python: allocate objects with ref pointers

Struct members that are marked as ref pointers need to have an object
allocated for them.

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Pair-programmed-with: Andrew Bartlett <abartlet@samba.org>
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Noel Power <npower@samba.org>

2 files changed, 56 insertions, 3 deletions

diff --git a/pidl/lib/Parse/Pidl/Samba4/Python.pm b/pidl/lib/Parse/Pidl/Samba4/Python.pm
index 8d5de31e7bb..fbb61c33580 100644
--- a/pidl/lib/Parse/Pidl/Samba4/Python.pm
+++ b/pidl/lib/Parse/Pidl/Samba4/Python.pm
@@ -499,7 +499,62 @@ sub PythonFunctionStruct($$$$)
 	$self->pidl("static PyObject *py_$name\_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)");
 	$self->pidl("{");
 	$self->indent;
-	$self->pidl("return pytalloc_new($cname, type);");
+
+	# This creates a new, zeroed C structure and python object.
+	# Thse may not be valid or sensible values, but this is as
+	# well as we can do.
+
+	$self->pidl("PyObject *self = pytalloc_new($cname, type);");
+
+	# If there are any children that are ref pointers, we need to
+	# allocate something for them to point to just as the pull
+	# routine will when parsing the stucture from NDR.
+	#
+	# We then make those pointers point to zeroed memory
+	#
+	# A ref pointer is a pointer in the C structure but a scalar
+	# on the wire. It is for a remote function like:
+	#
+	# int foo(int *i)
+	#
+	# This may be called with the pointer by reference eg foo(&i)
+	#
+	# That is why this only goes as far as the next level; deeply
+	# nested pointer chains will end in a NULL.
+
+	my @ref_elements;
+	foreach my $e (@{$fn->{ELEMENTS}}) {
+		if (has_property($e, "ref") && ! has_property($e, "charset")) {
+			if (!has_property($e, 'in') && !has_property($e, 'out')) {
+				die "ref pointer that is not in or out";
+			}
+			push @ref_elements, $e;
+		}
+	}
+	if (@ref_elements) {
+		$self->pidl("$cname *_self = ($cname *)pytalloc_get_ptr(self);");
+		$self->pidl("TALLOC_CTX *mem_ctx = pytalloc_get_mem_ctx(self);");
+		foreach my $e (@ref_elements) {
+			my $ename = $e->{NAME};
+			my $t = mapTypeName($e->{TYPE});
+			my $p = $e->{ORIGINAL}->{POINTERS} // 1;
+			if ($p > 1) {
+				$self->pidl("/* a pointer to a NULL pointer */");
+				$t .= ' ' . '*' x ($p - 1);
+			}
+
+			# We checked in the loop above that each ref
+			# pointer is in or out (or both)
+			if (has_property($e, 'in')) {
+				$self->pidl("_self->in.$ename = talloc_zero(mem_ctx, $t);");
+			}
+
+			if (has_property($e, 'out')) {
+				$self->pidl("_self->out.$ename = talloc_zero(mem_ctx, $t);");
+			}
+		}
+	}
+	$self->pidl("return self;");
 	$self->deindent;
 	$self->pidl("}");
 	$self->pidl("");
diff --git a/selftest/knownfail.d/python-segfaults b/selftest/knownfail.d/python-segfaults
index 671de9be4a2..e100356553d 100644
--- a/selftest/knownfail.d/python-segfaults
+++ b/selftest/knownfail.d/python-segfaults
@@ -1,4 +1,2 @@
 samba.tests.segfault.samba.tests.segfault.SegfaultTests.test_net_replicate_init__3
-samba.tests.segfault.samba.tests.segfault.SegfaultTests.test_dcerpc_idl_ref_elements
-samba.tests.segfault.samba.tests.segfault.SegfaultTests.test_dcerpc_idl_unixinfo_elements
 samba.tests.segfault.samba.tests.segfault.SegfaultTests.test_dcerpc_idl_inline_arrays