From 6cd260243aa735dc5201b765ab09fffe34c51ab0 Mon Sep 17 00:00:00 2001
From: sqian <shuoq@google.com>
Date: Mon, 27 Jan 2020 14:18:02 -0800
Subject: Support always reporting signal strength phone state listener

We should not allow other stack (such as Bluetooth) to directly control
 modem indication reporting. The hidden API
 TelephonyManager.setRadioIndicationUpdateMode added before do not
 support multiple clients and do not support the case when clients'
 process die.

The new solution would be adding a new listener
 PhoneStateListener.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH and let
 telephony registry (which is running under system process) to tell
 telephony whether to always turn on signal strength update if any client
 is listening to this event.

Introduce a new system API for TelephonyRegistry
to tell Telephony module this listening mechanism.

Introduce a new permision for this function

Test: WIP (Have this CL out to try to catch up the API deadline)
Bug: 147322848

Change-Id: Iaee832c75b29d89dbc9e5c6659e1a7e89c4a467f
Merged-In: Iaee832c75b29d89dbc9e5c6659e1a7e89c4a467f
(cherry picked from commit 93642d44330d5c124d20f4c00c09dc645987fda8)
---
 api/system-current.txt                             |  3 ++
 .../java/android/telephony/PhoneStateListener.java | 10 ++++++
 core/res/AndroidManifest.xml                       |  5 +++
 .../java/com/android/server/TelephonyRegistry.java | 38 ++++++++++++++++++++++
 .../java/android/telephony/TelephonyManager.java   | 21 ++++++++++++
 .../com/android/internal/telephony/ITelephony.aidl |  5 +++
 6 files changed, 82 insertions(+)

diff --git a/api/system-current.txt b/api/system-current.txt
index 44a1c0d79c13..e9eea1b79963 100755
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -93,6 +93,7 @@ package android {
     field public static final String INTERNAL_SYSTEM_WINDOW = "android.permission.INTERNAL_SYSTEM_WINDOW";
     field public static final String INVOKE_CARRIER_SETUP = "android.permission.INVOKE_CARRIER_SETUP";
     field public static final String KILL_UID = "android.permission.KILL_UID";
+    field public static final String LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH = "android.permission.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH";
     field public static final String LOCAL_MAC_ADDRESS = "android.permission.LOCAL_MAC_ADDRESS";
     field public static final String LOCK_DEVICE = "android.permission.LOCK_DEVICE";
     field public static final String LOOP_RADIO = "android.permission.LOOP_RADIO";
@@ -9083,6 +9084,7 @@ package android.telephony {
     method public void onRadioPowerStateChanged(int);
     method public void onSrvccStateChanged(int);
     method public void onVoiceActivationStateChanged(int);
+    field @RequiresPermission(android.Manifest.permission.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH) public static final int LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH = 512; // 0x200
     field @RequiresPermission("android.permission.READ_PRECISE_PHONE_STATE") public static final int LISTEN_CALL_ATTRIBUTES_CHANGED = 67108864; // 0x4000000
     field @RequiresPermission(android.Manifest.permission.READ_ACTIVE_EMERGENCY_SESSION) public static final int LISTEN_OUTGOING_EMERGENCY_CALL = 268435456; // 0x10000000
     field @RequiresPermission(android.Manifest.permission.READ_ACTIVE_EMERGENCY_SESSION) public static final int LISTEN_OUTGOING_EMERGENCY_SMS = 536870912; // 0x20000000
@@ -9534,6 +9536,7 @@ package android.telephony {
     method @RequiresPermission(android.Manifest.permission.CONNECTIVITY_INTERNAL) public void resetSettings();
     method @Deprecated @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public int setAllowedCarriers(int, java.util.List<android.service.carrier.CarrierIdentifier>);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public boolean setAllowedNetworkTypes(long);
+    method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setAlwaysReportSignalStrength(boolean);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setCarrierDataEnabled(boolean);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public int setCarrierRestrictionRules(@NonNull android.telephony.CarrierRestrictionRules);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setDataActivationState(int);
diff --git a/core/java/android/telephony/PhoneStateListener.java b/core/java/android/telephony/PhoneStateListener.java
index f886cf58b850..03e7361159e1 100644
--- a/core/java/android/telephony/PhoneStateListener.java
+++ b/core/java/android/telephony/PhoneStateListener.java
@@ -167,6 +167,16 @@ public class PhoneStateListener {
      */
     public static final int LISTEN_SIGNAL_STRENGTHS                         = 0x00000100;
 
+    /**
+     * Listen for always reported changes of the network signal strengths (cellular),
+     * even in some situations such as the screen of the device is off.
+     *
+     * @hide
+     */
+    @RequiresPermission(android.Manifest.permission.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH)
+    @SystemApi
+    public static final int LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH          = 0x00000200;
+
     /**
      * Listen for changes to observed cell info.
      *
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 5c204aba49a1..0c0493ba65aa 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -2082,6 +2082,11 @@
     <permission android:name="android.permission.READ_ACTIVE_EMERGENCY_SESSION"
         android:protectionLevel="signature" />
 
+    <!-- @SystemApi Allows listen permission to always reported signal strength.
+         @hide Used internally. -->
+    <permission android:name="android.permission.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH"
+        android:protectionLevel="signature|telephony" />
+
     <!-- @SystemApi Protects the ability to register any PhoneAccount with
          PhoneAccount#CAPABILITY_SIM_SUBSCRIPTION. This capability indicates that the PhoneAccount
          corresponds to a device SIM.
diff --git a/services/core/java/com/android/server/TelephonyRegistry.java b/services/core/java/com/android/server/TelephonyRegistry.java
index 62743aac55f6..5eacb28c76a9 100644
--- a/services/core/java/com/android/server/TelephonyRegistry.java
+++ b/services/core/java/com/android/server/TelephonyRegistry.java
@@ -882,6 +882,10 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
                             remove(r.binder);
                         }
                     }
+                    if ((events & PhoneStateListener.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH)
+                            != 0) {
+                        updateReportSignalStrengthDecision(r.subId);
+                    }
                     if (validateEventsAndUserLocked(r, PhoneStateListener.LISTEN_CELL_INFO)) {
                         try {
                             if (DBG_LOC) log("listen: mCellInfo[" + phoneId + "] = "
@@ -1005,6 +1009,27 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
         }
     }
 
+    private void updateReportSignalStrengthDecision(int subscriptionId) {
+        synchronized (mRecords) {
+            TelephonyManager telephonyManager = (TelephonyManager) mContext
+                    .getSystemService(Context.TELEPHONY_SERVICE);
+            for (Record r : mRecords) {
+                // If any of the system clients wants to always listen to signal strength,
+                // we need to set it on.
+                if (r.matchPhoneStateListenerEvent(
+                        PhoneStateListener.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH)) {
+                    telephonyManager.createForSubscriptionId(subscriptionId)
+                            .setAlwaysReportSignalStrength(true);
+                    return;
+                }
+            }
+            // If none of the system clients wants to always listen to signal strength,
+            // we need to set it off.
+            telephonyManager.createForSubscriptionId(subscriptionId)
+                    .setAlwaysReportSignalStrength(false);
+        }
+    }
+
     private String getCallIncomingNumber(Record record, int phoneId) {
         // Only reveal the incoming number if the record has read call log permission.
         return record.canReadCallLog() ? mCallIncomingNumber[phoneId] : "";
@@ -1062,6 +1087,14 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
                     }
 
                     mRecords.remove(i);
+
+                    // Every time a client that is registrating to always receive the signal
+                    // strength is removed from registry records, we need to check if
+                    // the signal strength decision needs to update on its slot.
+                    if (r.matchPhoneStateListenerEvent(
+                            PhoneStateListener.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH)) {
+                        updateReportSignalStrengthDecision(r.subId);
+                    }
                     return;
                 }
             }
@@ -2415,6 +2448,11 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
                     android.Manifest.permission.READ_ACTIVE_EMERGENCY_SESSION, null);
         }
 
+        if ((events & PhoneStateListener.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH) != 0) {
+            mContext.enforceCallingOrSelfPermission(
+                    android.Manifest.permission.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH, null);
+        }
+
         if ((events & PhoneStateListener.LISTEN_OEM_HOOK_RAW_EVENT) != 0) {
             mContext.enforceCallingOrSelfPermission(
                     android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE, null);
diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 173f84e81dae..ac2a0e55bad8 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -10576,6 +10576,27 @@ public class TelephonyManager {
         return true;
     }
 
+    /**
+     * Enable or disable signal strength changes from radio will always be reported in any
+     * condition (e.g. screen is off). This is only allowed for System caller.
+     *
+     * @param isEnabled {@code true} for enabling; {@code false} for disabling.
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE)
+    public void setAlwaysReportSignalStrength(boolean isEnabled) {
+        try {
+            ITelephony telephony = getITelephony();
+            if (telephony != null) {
+                telephony.setAlwaysReportSignalStrength(getSubId(), isEnabled);
+            }
+        } catch (RemoteException ex) {
+            Log.e(TAG, "setAlwaysReportSignalStrength RemoteException", ex);
+            ex.rethrowAsRuntimeException();
+        }
+    }
+
     /**
      * Get the most recently available signal strength information.
      *
diff --git a/telephony/java/com/android/internal/telephony/ITelephony.aidl b/telephony/java/com/android/internal/telephony/ITelephony.aidl
index dfb4ee50f7cc..99b71e84c77a 100644
--- a/telephony/java/com/android/internal/telephony/ITelephony.aidl
+++ b/telephony/java/com/android/internal/telephony/ITelephony.aidl
@@ -994,6 +994,11 @@ interface ITelephony {
      */
      boolean isManualNetworkSelectionAllowed(int subId);
 
+    /**
+     * Enable or disable always reporting signal strength changes from radio.
+     */
+     void setAlwaysReportSignalStrength(int subId, boolean isEnable);
+
     /**
      * Get P-CSCF address from PCO after data connection is established or modified.
      * @param apnType the apnType, "ims" for IMS APN, "emergency" for EMERGENCY APN
-- 
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