Binder: support storing interface stability
This adds runtime information for what the stability class of a binder
is in preparation for allowing binders system<->vendor. However, this
shouldn't necessarily be restricted to this case. For instance, it may
also be used to separate APEX interface stability levels. The idea is
that for code serving an interface of a given stability, only intefaces
of greater stability can be sent to it. This is slightly less
restrictive than existing binder domains. For instance, this could
potentially support having a single interface 'vintf' interface which is
shared by both system and vendor (this removing the need for infra like
ITokenManager).
The API that is exposed only allows marking a binder as a specific
stability class (see Stability.h). For instance, 'markVintf' marks an
API as being exposed system<->vendor. Although, infrastructure in
servicemanager, aidl, sepolicy, and VTS still need to support this in
order to be useful.
The actual implementation of these stability classes (bitmasks) is not
exposed and may be changed arbitrarily. Currently these bitmasks are
32-bit integers. These are sent to other processes because the type
system in AIDL cannot encode the stability requirements here without
either dropping IBinder or differentating IBinder by stability level
(which we don't want). So, where possible, AIDL will differentiate
stability level at compile time, but when IBinder is used, for
handwritten interfaces, and as a backup in case any other piece of the
infrastructure fails, the stability is also checked at runtime.
Bug: 136027762
Test: atest binderStabilityTest
Change-Id: Ia637ee3652d55550e7fce78876458f391b1dd928
diff --git a/libs/binder/tests/binderStabilityTest.cpp b/libs/binder/tests/binderStabilityTest.cpp
new file mode 100644
index 0000000..2b27a81
--- /dev/null
+++ b/libs/binder/tests/binderStabilityTest.cpp
@@ -0,0 +1,245 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <android/os/IServiceManager.h>
+#include <binder/Binder.h>
+#include <binder/IBinder.h>
+#include <binder/IPCThreadState.h>
+#include <binder/IServiceManager.h>
+#include <binder/Parcel.h>
+#include <binder/Stability.h>
+#include <gtest/gtest.h>
+
+#include <sys/prctl.h>
+
+#include "BnBinderStabilityTest.h"
+#include "BpBinderStabilityTest.h"
+
+using namespace android;
+using android::binder::Status;
+using android::os::IServiceManager;
+
+const String16 kNoStabilityServer = String16("binder_stability_test_service_low");
+const String16 kCompilationUnitServer = String16("binder_stability_test_service_compl");
+const String16 kVintfServer = String16("binder_stability_test_service_vintf");
+
+sp<IBinder> getCompilationUnitStability() {
+ sp<IBinder> binder = new BBinder();
+ // NO! NO! NO! NO! DO NOT EVERY DO SOMETHING LIKE THIS?
+ // WHAT ARE YOU CRAZY? IT'S VERY DANGEROUS
+ internal::Stability::markCompilationUnit(binder.get()); // <- BAD, NO! DO NOT COPY
+ return binder;
+}
+
+sp<IBinder> getVintfStability() {
+ sp<IBinder> binder = new BBinder();
+ // NO! NO! NO! NO! DO NOT EVERY DO SOMETHING LIKE THIS?
+ // WHAT ARE YOU CRAZY? IT'S VERY DANGEROUS
+ internal::Stability::markVintf(binder.get()); // <- BAD, NO! DO NOT COPY
+ return binder;
+}
+
+// NO! NO! NO! Do not even think of doing something like this!
+// This is for testing! If a class like this was actually used in production,
+// it would ruin everything!
+class BadStabilityTester : public BnBinderStabilityTest {
+public:
+ Status sendBinder(const sp<IBinder>& /*binder*/) override {
+ return Status::ok();
+ }
+ Status returnNoStabilityBinder(sp<IBinder>* _aidl_return) override {
+ *_aidl_return = new BBinder();
+ return Status::ok();
+ }
+ Status returnLocalStabilityBinder(sp<IBinder>* _aidl_return) override {
+ *_aidl_return = getCompilationUnitStability();
+ return Status::ok();
+ }
+ Status returnVintfStabilityBinder(sp<IBinder>* _aidl_return) override {
+ *_aidl_return = getVintfStability();
+ return Status::ok();
+ }
+
+ static sp<IBinderStabilityTest> getNoStabilityServer() {
+ sp<IBinder> remote = new BadStabilityTester;
+ return new BpBinderStabilityTest(remote);
+ }
+ static sp<IBinderStabilityTest> getCompilationUnitStabilityServer() {
+ sp<IBinder> remote = new BadStabilityTester;
+ internal::Stability::markCompilationUnit(remote.get());
+ return new BpBinderStabilityTest(remote);
+ }
+ static sp<IBinderStabilityTest> getVintfStabilityServer() {
+ sp<IBinder> remote = new BadStabilityTester;
+ internal::Stability::markVintf(remote.get()); // <- BAD, NO! DO NOT COPY
+ return new BpBinderStabilityTest(remote);
+ }
+};
+
+void checkNoStabilityServer(const sp<IBinderStabilityTest>& unkemptServer) {
+ EXPECT_TRUE(unkemptServer->sendBinder(new BBinder()).isOk());
+ EXPECT_TRUE(unkemptServer->sendBinder(getCompilationUnitStability()).isOk());
+ EXPECT_TRUE(unkemptServer->sendBinder(getVintfStability()).isOk());
+
+ sp<IBinder> out;
+ EXPECT_TRUE(unkemptServer->returnNoStabilityBinder(&out).isOk());
+ EXPECT_NE(nullptr, out.get());
+
+ EXPECT_TRUE(unkemptServer->returnLocalStabilityBinder(&out).isOk());
+ EXPECT_NE(nullptr, out.get());
+
+ EXPECT_TRUE(unkemptServer->returnVintfStabilityBinder(&out).isOk());
+ EXPECT_NE(nullptr, out.get());
+}
+
+void checkLowStabilityServer(const sp<IBinderStabilityTest>& complServer) {
+ EXPECT_FALSE(complServer->sendBinder(new BBinder()).isOk());
+ EXPECT_TRUE(complServer->sendBinder(getCompilationUnitStability()).isOk());
+ EXPECT_TRUE(complServer->sendBinder(getVintfStability()).isOk());
+
+ sp<IBinder> out;
+ EXPECT_FALSE(complServer->returnNoStabilityBinder(&out).isOk());
+ EXPECT_EQ(nullptr, out.get());
+
+ EXPECT_TRUE(complServer->returnLocalStabilityBinder(&out).isOk());
+ EXPECT_NE(nullptr, out.get());
+
+ EXPECT_TRUE(complServer->returnVintfStabilityBinder(&out).isOk());
+ EXPECT_NE(nullptr, out.get());
+}
+
+void checkHighStabilityServer(const sp<IBinderStabilityTest>& highStability) {
+ EXPECT_FALSE(highStability->sendBinder(new BBinder()).isOk());
+ EXPECT_FALSE(highStability->sendBinder(getCompilationUnitStability()).isOk());
+ EXPECT_TRUE(highStability->sendBinder(getVintfStability()).isOk());
+
+ sp<IBinder> out;
+ EXPECT_FALSE(highStability->returnNoStabilityBinder(&out).isOk());
+ EXPECT_EQ(nullptr, out.get());
+
+ EXPECT_FALSE(highStability->returnLocalStabilityBinder(&out).isOk());
+ EXPECT_EQ(nullptr, out.get());
+
+ EXPECT_TRUE(highStability->returnVintfStabilityBinder(&out).isOk());
+ EXPECT_NE(nullptr, out.get());
+}
+
+TEST(BinderStability, LocalNoStabilityServer) {
+ // in practice, a low stability server is probably one that hasn't been rebuilt
+ // or was written by hand.
+ auto server = BadStabilityTester::getNoStabilityServer();
+ ASSERT_NE(nullptr, IInterface::asBinder(server)->localBinder());
+ checkNoStabilityServer(server);
+}
+
+TEST(BinderStability, LocalLowStabilityServer) {
+ auto server = BadStabilityTester::getCompilationUnitStabilityServer();
+ ASSERT_NE(nullptr, IInterface::asBinder(server)->localBinder());
+ checkLowStabilityServer(server);
+}
+
+TEST(BinderStability, LocalHighStabilityServer) {
+ auto server = BadStabilityTester::getVintfStabilityServer();
+ ASSERT_NE(nullptr, IInterface::asBinder(server)->localBinder());
+ checkHighStabilityServer(server);
+}
+
+TEST(BinderStability, RemoteNoStabilityServer) {
+ sp<IBinder> remoteBinder = android::defaultServiceManager()->getService(kNoStabilityServer);
+ auto remoteServer = interface_cast<IBinderStabilityTest>(remoteBinder);
+
+ ASSERT_NE(nullptr, remoteServer.get());
+ ASSERT_NE(nullptr, IInterface::asBinder(remoteServer)->remoteBinder());
+
+ checkNoStabilityServer(remoteServer);
+}
+
+TEST(BinderStability, RemoteLowStabilityServer) {
+ sp<IBinder> remoteBinder = android::defaultServiceManager()->getService(kCompilationUnitServer);
+ auto remoteServer = interface_cast<IBinderStabilityTest>(remoteBinder);
+
+ ASSERT_NE(nullptr, remoteServer.get());
+ ASSERT_NE(nullptr, IInterface::asBinder(remoteServer)->remoteBinder());
+
+ checkLowStabilityServer(remoteServer);
+}
+
+TEST(BinderStability, RemoteVintfServer) {
+ sp<IBinder> remoteBinder = android::defaultServiceManager()->getService(kVintfServer);
+ auto remoteServer = interface_cast<IBinderStabilityTest>(remoteBinder);
+
+ ASSERT_NE(nullptr, remoteServer.get());
+ ASSERT_NE(nullptr, IInterface::asBinder(remoteServer)->remoteBinder());
+
+ checkHighStabilityServer(remoteServer);
+}
+
+class MarksStabilityInConstructor : public BBinder {
+public:
+ static bool gDestructed;
+
+ MarksStabilityInConstructor() {
+ internal::Stability::markCompilationUnit(this);
+ }
+ ~MarksStabilityInConstructor() {
+ gDestructed = true;
+ }
+};
+bool MarksStabilityInConstructor::gDestructed = false;
+
+TEST(BinderStability, MarkingObjectNoDestructTest) {
+ ASSERT_FALSE(MarksStabilityInConstructor::gDestructed);
+
+ // best practice is to put this directly in an sp, but for this test, we
+ // want to explicitly check what happens before that happens
+ MarksStabilityInConstructor* binder = new MarksStabilityInConstructor();
+ ASSERT_FALSE(MarksStabilityInConstructor::gDestructed);
+
+ sp<MarksStabilityInConstructor> binderSp = binder;
+ ASSERT_FALSE(MarksStabilityInConstructor::gDestructed);
+
+ binderSp = nullptr;
+ ASSERT_TRUE(MarksStabilityInConstructor::gDestructed);
+}
+
+int main(int argc, char** argv) {
+ ::testing::InitGoogleTest(&argc, argv);
+
+ if (fork() == 0) {
+ // child process
+ prctl(PR_SET_PDEATHSIG, SIGHUP);
+
+ sp<IBinder> noStability = new BadStabilityTester;
+ android::defaultServiceManager()->addService(kNoStabilityServer, noStability);
+
+ sp<IBinder> compil = new BadStabilityTester;
+ internal::Stability::markCompilationUnit(compil.get());
+ android::defaultServiceManager()->addService(kCompilationUnitServer, compil);
+
+ sp<IBinder> vintf = new BadStabilityTester;
+ internal::Stability::markVintf(vintf.get());
+ android::defaultServiceManager()->addService(kVintfServer, vintf);
+
+ IPCThreadState::self()->joinThreadPool(true);
+ exit(1); // should not reach
+ }
+
+ // This is not racey. Just giving these services some time to register before we call
+ // getService which sleeps for much longer...
+ usleep(10000);
+
+ return RUN_ALL_TESTS();
+}