Add tests for RPC Meta protocol

This adds test to query the protocol support of the object behind a
capability and information about the number of protocols spoken.

Change-Id: Ie5f81dda27cd96638e20e93ceebd9c359f5731fd

test/l4sys/test_meta.cc

@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 2019 Kernkonzept GmbH.
+ * Author(s): Marcus Hähnel <marcus.haehnel@kernkonzept.com>
+ *
+ * This file is distributed under the terms of the GNU General Public
+ * License, version 2.  Please see the COPYING-GPL-2 file for details.
+ */
+
+/**
+ * \file
+ *
+ * Tests for the RPC meta protocol.
+ */
+
+#include <l4/sys/factory>
+
+#include <l4/re/env>
+#include <l4/re/util/unique_cap>
+#include <l4/re/error_helper>
+#include <l4/re/namespace>
+#include <l4/re/dataspace>
+#include <l4/re/dma_space>
+#include <l4/re/mem_alloc>
+#include <l4/re/rm>
+
+#include <l4/atkins/tap/main>
+
+static L4Re::Env const *const env = L4Re::Env::env();
+
+/**
+ * Allocator functions for the different capabilities.
+ *
+ * This template covers all types that do not need special arguments upon
+ * creation.
+ */
+template <typename T>
+static l4_msgtag_t
+alloc_cap(L4::Cap<T> cap)
+{
+  return env->mem_alloc()->create(cap);
+}
+
+template <>
+l4_msgtag_t
+alloc_cap(L4::Cap<L4Re::Dataspace> cap)
+{
+  return env->mem_alloc()->create(cap, L4Re::Dataspace::Protocol)
+         << l4_umword_t(L4_PAGESIZE) // Size
+         << l4_umword_t(0)           // Flags
+         << l4_umword_t(0);          // Alignment
+}
+
+template <>
+l4_msgtag_t
+alloc_cap(L4::Cap<L4Re::Mem_alloc> cap)
+{
+  return env->mem_alloc()->create_factory(cap, 10 * L4_PAGESIZE);
+}
+
+template <>
+l4_msgtag_t
+alloc_cap(L4::Cap<L4::Factory> cap)
+{
+  return env->mem_alloc()->create_factory(cap, 10 * L4_PAGESIZE);
+}
+
+/**
+ * Type-parameterised test fixture
+ *
+ * This fixture allocates a capability for the template type and calls the
+ * corresponding factory to create an object of that type. It then provides a
+ * capability for speaking the Meta protocol with this object through the `_cap`
+ * member.
+ */
+template <typename T>
+class RPCMeta : public ::testing::Test
+{
+public:
+  virtual void SetUp() override
+  {
+    _cap = L4Re::chkcap(L4Re::Util::make_unique_del_cap<T>(),
+                        "Capability allocated successfully");
+    L4Re::chksys(alloc_cap(_cap.get()), "Object created successfully");
+    _meta = L4::cap_reinterpret_cast<L4::Meta>(_cap.get());
+  }
+
+protected:
+  L4Re::Util::Unique_del_cap<T> _cap;
+  L4::Cap<L4::Meta> _meta;
+};
+
+typedef testing::Types<L4Re::Namespace, L4Re::Dataspace, L4Re::Dma_space,
+                       L4Re::Rm, L4Re::Mem_alloc, L4::Factory>
+  TestTypes;
+
+TYPED_TEST_CASE(RPCMeta, TestTypes);
+
+/**
+ * RPC interfaces for an object support at least one interface.
+ */
+TYPED_TEST(RPCMeta, NumInterfaces)
+{
+  ASSERT_LE(1, this->_meta->num_interfaces().label())
+    << "At least one interface is supported by the IPC partner";
+}
+
+/**
+ * The RPC interface of an object supports the interface for which the
+ * capability was created.
+ */
+TYPED_TEST(RPCMeta, SupportsIface)
+{
+  ASSERT_EQ(this->_meta->supports(TypeParam::Protocol).label(), 1)
+    << "The object speaks the interface for which the capability was created.";
+}
+
+/**
+ * The string description of an interface is non-empty.
+ */
+TYPED_TEST(RPCMeta, FirstInterface)
+{
+  long proto;
+  char namec[256] = {0};
+  L4::Ipc::String<char> name(sizeof(namec), namec);
+  EXPECT_EQ(this->_meta->interface(0, &proto, &name).label(), 0)
+    << "Information of interface 0 can be queried.";
+  ASSERT_GT(strlen(namec), 0ul)
+    << "A string description of the interface can be obtained.";
+}
+