Add CDM dependency in Tethering

This change introduces a limited library for dependencies on
framework-connectivity from Tethering,
connectivity-internal-api-util, where all classes are annotated with
@RequiresApi(S) to ensure proper API checks are done before usage.

Bug: 245972418

Change-Id: I82bafd9063341adc71d07f0858e6d68283d081f0

Tethering/Android.bp

@@ -34,6 +34,7 @@ java_defaults {
     // Libraries not including Tethering's own framework-tethering (different flavors of that one
     // are needed depending on the build rule)
     libs: [
+        "connectivity-internal-api-util",
         "framework-configinfrastructure",
         "framework-connectivity.stubs.module_lib",
         "framework-connectivity-t.stubs.module_lib",

Tethering/apex/Android.bp

@@ -199,6 +199,7 @@ bootclasspath_fragment {
             "android.net.connectivity",
             "android.net.netstats.provider",
             "android.net.nsd",
+            "android.net.wear",
         ],
     },
 }

Tethering/common/TetheringLib/Android.bp

@@ -22,6 +22,10 @@ java_sdk_library {
     defaults: ["framework-module-defaults"],
     impl_library_visibility: [
         "//packages/modules/Connectivity/Tethering:__subpackages__",
+        "//packages/modules/Connectivity/framework",
+        "//packages/modules/Connectivity/framework-t",
+        "//packages/modules/Connectivity/service",
+        "//packages/modules/Connectivity/service-t",
 
         // Using for test only
         "//cts/tests/netlegacy22.api",
@@ -64,19 +68,8 @@ java_sdk_library {
 filegroup {
     name: "framework-tethering-srcs",
     srcs: [
-        "src/android/net/TetheredClient.aidl",
+        "src/**/*.aidl",
-        "src/android/net/TetheredClient.java",
+        "src/**/*.java",
-        "src/android/net/TetheringManager.java",
-        "src/android/net/TetheringConstants.java",
-        "src/android/net/IIntResultListener.aidl",
-        "src/android/net/ITetheringEventCallback.aidl",
-        "src/android/net/ITetheringConnector.aidl",
-        "src/android/net/TetheringCallbackStartedParcel.aidl",
-        "src/android/net/TetheringConfigurationParcel.aidl",
-        "src/android/net/TetheringRequestParcel.aidl",
-        "src/android/net/TetherStatesParcel.aidl",
-        "src/android/net/TetheringInterface.aidl",
-        "src/android/net/TetheringInterface.java",
     ],
     path: "src"
 }

Tethering/common/TetheringLib/src/android/net/wear/ICompanionDeviceManagerProxy.aidl

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+package android.net.wear;
+
+import android.companion.AssociationInfo;
+
+/** @hide */
+interface ICompanionDeviceManagerProxy {
+    List<AssociationInfo> getAllAssociations();
+}

Tethering/src/com/android/networkstack/tethering/wear/CompanionDeviceManagerProxy.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+package com.android.networkstack.tethering.wear;
+
+import android.companion.AssociationInfo;
+import android.companion.CompanionDeviceManager;
+import android.content.Context;
+import android.net.connectivity.TiramisuConnectivityInternalApiUtil;
+import android.net.wear.ICompanionDeviceManagerProxy;
+import android.os.Build;
+import android.os.RemoteException;
+
+import androidx.annotation.RequiresApi;
+
+import java.util.List;
+
+/**
+ * A proxy for {@link android.companion.CompanionDeviceManager}, allowing Tethering to call it with
+ * a different set of permissions.
+ * @hide
+ */
+public class CompanionDeviceManagerProxy {
+    private final ICompanionDeviceManagerProxy mService;
+
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
+    public CompanionDeviceManagerProxy(Context context) {
+        mService = ICompanionDeviceManagerProxy.Stub.asInterface(
+                TiramisuConnectivityInternalApiUtil.getCompanionDeviceManagerProxyService(context));
+    }
+
+    /**
+     * @see CompanionDeviceManager#getAllAssociations()
+     */
+    public List<AssociationInfo> getAllAssociations() {
+        try {
+            return mService.getAllAssociations();
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+}

framework/Android.bp

@@ -80,7 +80,9 @@ java_defaults {
         "framework-connectivity-t.stubs.module_lib",
     ],
     impl_only_libs: [
-        "framework-tethering.stubs.module_lib",
+        // TODO: figure out why just using "framework-tethering" uses the stubs, even though both
+        // framework-connectivity and framework-tethering are in the same APEX.
+        "framework-tethering.impl",
         "framework-wifi.stubs.module_lib",
         "net-utils-device-common",
     ],
@@ -109,9 +111,9 @@ java_library {
     libs: [
         // This cannot be in the defaults clause above because if it were, it would be used
         // to generate the connectivity stubs. That would create a circular dependency
-        // because the tethering stubs depend on the connectivity stubs (e.g.,
+        // because the tethering impl depend on the connectivity stubs (e.g.,
         // TetheringRequest depends on LinkAddress).
-        "framework-tethering.stubs.module_lib",
+        "framework-tethering.impl",
         "framework-wifi.stubs.module_lib",
     ],
     visibility: ["//packages/modules/Connectivity:__subpackages__"]
@@ -243,3 +245,24 @@ java_genrule {
         "//packages/modules/Connectivity/service",
     ],
 }
+
+// Library providing limited APIs within the connectivity module, so that R+ components like
+// Tethering have a controlled way to depend on newer components like framework-connectivity that
+// are not loaded on R.
+java_library {
+    name: "connectivity-internal-api-util",
+    sdk_version: "module_current",
+    libs: [
+        "androidx.annotation_annotation",
+        "framework-connectivity.impl",
+    ],
+    jarjar_rules: ":framework-connectivity-jarjar-rules",
+    srcs: [
+        // Files listed here MUST all be annotated with @RequiresApi(Build.VERSION_CODES.TIRAMISU),
+        // so that API checks are enforced for R+ users of this library
+        "src/android/net/connectivity/TiramisuConnectivityInternalApiUtil.java",
+    ],
+    visibility: [
+        "//packages/modules/Connectivity/Tethering:__subpackages__",
+    ],
+}

framework/src/android/net/ConnectivityManager.java

@@ -5992,4 +5992,13 @@ public class ConnectivityManager {
             throw e.rethrowFromSystemServer();
         }
     }
+
+    /** @hide */
+    public IBinder getCompanionDeviceManagerProxyService() {
+        try {
+            return mService.getCompanionDeviceManagerProxyService();
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
 }

framework/src/android/net/IConnectivityManager.aidl

@@ -247,4 +247,6 @@ interface IConnectivityManager
     boolean getFirewallChainEnabled(int chain);
 
     void replaceFirewallChain(int chain, in int[] uids);
+
+    IBinder getCompanionDeviceManagerProxyService();
 }

framework/src/android/net/connectivity/TiramisuConnectivityInternalApiUtil.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+package android.net.connectivity;
+
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.os.Build;
+import android.os.IBinder;
+
+import androidx.annotation.RequiresApi;
+
+/**
+ * Utility providing limited access to module-internal APIs which are only available on Android T+,
+ * as this class is only in the bootclasspath on T+ as part of framework-connectivity.
+ *
+ * R+ module components like Tethering cannot depend on all hidden symbols from
+ * framework-connectivity. They only have access to stable API stubs where newer APIs can be
+ * accessed after an API level check (enforced by the linter), or to limited hidden symbols in this
+ * class which is also annotated with @RequiresApi (so API level checks are also enforced by the
+ * linter).
+ * @hide
+ */
+@RequiresApi(Build.VERSION_CODES.TIRAMISU)
+public class TiramisuConnectivityInternalApiUtil {
+
+    /**
+     * Get a service binder token for
+     * {@link com.android.server.connectivity.wear.CompanionDeviceManagerProxyService}.
+     */
+    public static IBinder getCompanionDeviceManagerProxyService(Context ctx) {
+        final ConnectivityManager cm = ctx.getSystemService(ConnectivityManager.class);
+        return cm.getCompanionDeviceManagerProxyService();
+    }
+}

service-t/Android.bp

@@ -50,7 +50,8 @@ java_library {
         "framework-configinfrastructure",
         "framework-connectivity-pre-jarjar",
         "framework-connectivity-t-pre-jarjar",
-        "framework-tethering",
+        // TODO: use framework-tethering-pre-jarjar when it is separated from framework-tethering
+        "framework-tethering.impl",
         "service-connectivity-pre-jarjar",
         "service-nearby-pre-jarjar",
         "ServiceConnectivityResources",

service/Android.bp

@@ -157,7 +157,9 @@ java_library {
         // against the implementation because the two libraries are in the same
         // APEX.
         "framework-connectivity-t.stubs.module_lib",
-        "framework-tethering",
+        // TODO: figure out why just using "framework-tethering" uses the stubs, even though both
+        // service-connectivity and framework-tethering are in the same APEX.
+        "framework-tethering.impl",
         "framework-wifi",
         "unsupportedappusage",
         "ServiceConnectivityResources",
@@ -166,6 +168,7 @@ java_library {
     static_libs: [
         // Do not add libs here if they are already included
         // in framework-connectivity
+        "androidx.annotation_annotation",
         "connectivity-net-module-utils-bpf",
         "connectivity_native_aidl_interface-lateststable-java",
         "dnsresolver_aidl_interface-V9-java",
@@ -258,7 +261,7 @@ java_defaults {
         "framework-annotations-lib",
         "framework-connectivity.impl",
         "framework-connectivity-t.impl",
-        "framework-tethering",
+        "framework-tethering.impl",
         "framework-wifi",
         "libprotobuf-java-nano",
     ],

service/src/com/android/server/ConnectivityService.java

@@ -286,6 +286,7 @@ import com.android.server.connectivity.ProfileNetworkPreferenceInfo;
 import com.android.server.connectivity.ProxyTracker;
 import com.android.server.connectivity.QosCallbackTracker;
 import com.android.server.connectivity.UidRangeUtils;
+import com.android.server.connectivity.wear.CompanionDeviceManagerProxyService;
 
 import libcore.io.IoUtils;
 
@@ -435,6 +436,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
      */
     @GuardedBy("mTNSLock")
     private TestNetworkService mTNS;
+    private final CompanionDeviceManagerProxyService mCdmps;
 
     private final Object mTNSLock = new Object();
 
@@ -1586,6 +1588,12 @@ public class ConnectivityService extends IConnectivityManager.Stub
 
         mIngressRateLimit = ConnectivitySettingsManager.getIngressRateLimitInBytesPerSecond(
                 mContext);
+
+        if (SdkLevel.isAtLeastT()) {
+            mCdmps = new CompanionDeviceManagerProxyService(context);
+        } else {
+            mCdmps = null;
+        }
     }
 
     /**
@@ -11491,4 +11499,10 @@ public class ConnectivityService extends IConnectivityManager.Stub
 
         mBpfNetMaps.replaceUidChain(chain, uids);
     }
+
+    @Override
+    public IBinder getCompanionDeviceManagerProxyService() {
+        enforceNetworkStackPermission(mContext);
+        return mCdmps;
+    }
 }

service/src/com/android/server/connectivity/wear/CompanionDeviceManagerProxyService.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+package com.android.server.connectivity.wear;
+
+import android.companion.AssociationInfo;
+import android.companion.CompanionDeviceManager;
+import android.content.Context;
+import android.net.wear.ICompanionDeviceManagerProxy;
+import android.os.Binder;
+import android.os.Build;
+
+import androidx.annotation.RequiresApi;
+
+import com.android.net.module.util.PermissionUtils;
+
+import java.util.List;
+
+/**
+ * A proxy for {@link CompanionDeviceManager}, for use by Tethering with NetworkStack permissions.
+ */
+public class CompanionDeviceManagerProxyService extends ICompanionDeviceManagerProxy.Stub {
+    private final Context mContext;
+
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
+    public CompanionDeviceManagerProxyService(Context context) {
+        mContext = context;
+    }
+
+    @Override
+    public List<AssociationInfo> getAllAssociations() {
+        PermissionUtils.enforceNetworkStackPermission(mContext);
+        final long token = Binder.clearCallingIdentity();
+        try {
+            final CompanionDeviceManager cdm = mContext.getSystemService(
+                    CompanionDeviceManager.class);
+            return cdm.getAllAssociations();
+        } finally {
+            Binder.restoreCallingIdentity(token);
+        }
+    }
+}