src/java/com/android/internal/telephony/gsm/GsmInboundSmsHandler.java

/*
 * Copyright (C) 2013 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.internal.telephony.gsm;

import android.app.Activity;
import android.compat.annotation.UnsupportedAppUsage;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.AsyncResult;
import android.os.Build;
import android.os.Message;
import android.os.SystemProperties;
import android.provider.Telephony.Sms.Intents;

import com.android.internal.telephony.CommandsInterface;
import com.android.internal.telephony.InboundSmsHandler;
import com.android.internal.telephony.Phone;
import com.android.internal.telephony.SmsConstants;
import com.android.internal.telephony.SmsHeader;
import com.android.internal.telephony.SmsMessageBase;
import com.android.internal.telephony.SmsStorageMonitor;
import com.android.internal.telephony.VisualVoicemailSmsFilter;
import com.android.internal.telephony.uicc.UsimServiceTable;

/**
 * Subclass of {@link InboundSmsHandler} for 3GPP type messages.
 */
public class GsmInboundSmsHandler extends InboundSmsHandler {

    private static BroadcastReceiver sTestBroadcastReceiver;
    /** Handler for SMS-PP data download messages to UICC. */
    private final UsimDataDownloadHandler mDataDownloadHandler;

    // When TEST_MODE is on we allow the test intent to trigger an SMS CB alert
    private static final boolean TEST_MODE = SystemProperties.getInt("ro.debuggable", 0) == 1;
    private static final String TEST_ACTION = "com.android.internal.telephony.gsm"
            + ".TEST_TRIGGER_CELL_BROADCAST";

    /**
     * Create a new GSM inbound SMS handler.
     */
    private GsmInboundSmsHandler(Context context, SmsStorageMonitor storageMonitor,
            Phone phone) {
        super("GsmInboundSmsHandler", context, storageMonitor, phone);
        phone.mCi.setOnNewGsmSms(getHandler(), EVENT_NEW_SMS, null);
        mDataDownloadHandler = new UsimDataDownloadHandler(phone.mCi, phone.getPhoneId());
        mCellBroadcastServiceManager.enable();

        if (TEST_MODE) {
            if (sTestBroadcastReceiver == null) {
                sTestBroadcastReceiver = new GsmCbTestBroadcastReceiver();
                IntentFilter filter = new IntentFilter();
                filter.addAction(TEST_ACTION);
                context.registerReceiver(sTestBroadcastReceiver, filter);
            }
        }
    }


    /**
     * A broadcast receiver used for testing emergency cell broadcasts. To trigger test GSM cell
     * broadcasts with adb run e.g:
     *
     * adb shell am broadcast -a com.android.internal.telephony.gsm.TEST_TRIGGER_CELL_BROADCAST \
     * --es pdu_string  0000110011010D0A5BAE57CE770C531790E85C716CBF3044573065B9306757309707767 \
     * A751F30025F37304463FA308C306B5099304830664E0B30553044FF086C178C615E81FF09000000000000000 \
     * 0000000000000
     *
     * adb shell am broadcast -a com.android.internal.telephony.gsm.TEST_TRIGGER_CELL_BROADCAST \
     * --es pdu_string  0000110011010D0A5BAE57CE770C531790E85C716CBF3044573065B9306757309707767 \
     * A751F30025F37304463FA308C306B5099304830664E0B30553044FF086C178C615E81FF09000000000000000 \
     * 0000000000000 --ei phone_id 0
     */
    private class GsmCbTestBroadcastReceiver extends CbTestBroadcastReceiver {

        GsmCbTestBroadcastReceiver() {
            super(TEST_ACTION);
        }

        @Override
        protected void handleTestAction(Intent intent) {
            byte[] smsPdu = intent.getByteArrayExtra("pdu");
            if (smsPdu == null) {
                String pduString = intent.getStringExtra("pdu_string");
                smsPdu = decodeHexString(pduString);
            }
            if (smsPdu == null) {
                log("No pdu or pdu_string extra, ignoring CB test intent");
                return;
            }

            Message m = Message.obtain();
            AsyncResult.forMessage(m, smsPdu, null);
            mCellBroadcastServiceManager.sendGsmMessageToHandler(m);
        }
    }

    /**
     * Unregister for GSM SMS.
     */
    @Override
    protected void onQuitting() {
        mPhone.mCi.unSetOnNewGsmSms(getHandler());

        if (DBG) log("unregistered for 3GPP SMS");
        super.onQuitting();     // release wakelock
    }

    /**
     * Wait for state machine to enter startup state. We can't send any messages until then.
     */
    public static GsmInboundSmsHandler makeInboundSmsHandler(Context context,
            SmsStorageMonitor storageMonitor, Phone phone) {
        GsmInboundSmsHandler handler = new GsmInboundSmsHandler(context, storageMonitor, phone);
        handler.start();
        return handler;
    }

    /**
     * Return true if this handler is for 3GPP2 messages; false for 3GPP format.
     *
     * @return false (3GPP)
     */
    @Override
    protected boolean is3gpp2() {
        return false;
    }

    /**
     * Handle type zero, SMS-PP data download, and 3GPP/CPHS MWI type SMS. Normal SMS messages
     * are handled by {@link #dispatchNormalMessage} in parent class.
     *
     * @param smsb the SmsMessageBase object from the RIL
     * @param smsSource the source of the SMS message
     * @return a result code from {@link android.provider.Telephony.Sms.Intents},
     * or {@link Activity#RESULT_OK} for delayed acknowledgment to SMSC
     */
    @Override
    protected int dispatchMessageRadioSpecific(SmsMessageBase smsb, @SmsSource int smsSource) {
        SmsMessage sms = (SmsMessage) smsb;

        if (sms.isTypeZero()) {
            // Some carriers will send visual voicemail SMS as type zero.
            int destPort = -1;
            SmsHeader smsHeader = sms.getUserDataHeader();
            if (smsHeader != null && smsHeader.portAddrs != null) {
                // The message was sent to a port.
                destPort = smsHeader.portAddrs.destPort;
            }
            VisualVoicemailSmsFilter
                    .filter(mContext, new byte[][]{sms.getPdu()}, SmsConstants.FORMAT_3GPP,
                            destPort, mPhone.getSubId());
            // As per 3GPP TS 23.040 9.2.3.9, Type Zero messages should not be
            // Displayed/Stored/Notified. They should only be acknowledged.
            log("Received short message type 0, Don't display or store it. Send Ack");
            addSmsTypeZeroToMetrics(smsSource);
            return Intents.RESULT_SMS_HANDLED;
        }

        // Send SMS-PP data download messages to UICC. See 3GPP TS 31.111 section 7.1.1.
        if (sms.isUsimDataDownload()) {
            UsimServiceTable ust = mPhone.getUsimServiceTable();
            return mDataDownloadHandler.handleUsimDataDownload(ust, sms, smsSource);
        }

        boolean handled = false;
        if (sms.isMWISetMessage()) {
            updateMessageWaitingIndicator(sms.getNumOfVoicemails());
            handled = sms.isMwiDontStore();
            if (DBG) log("Received voice mail indicator set SMS shouldStore=" + !handled);
        } else if (sms.isMWIClearMessage()) {
            updateMessageWaitingIndicator(0);
            handled = sms.isMwiDontStore();
            if (DBG) log("Received voice mail indicator clear SMS shouldStore=" + !handled);
        }
        if (handled) {
            addVoicemailSmsToMetrics(smsSource);
            return Intents.RESULT_SMS_HANDLED;
        }

        if (!mStorageMonitor.isStorageAvailable() &&
                sms.getMessageClass() != SmsConstants.MessageClass.CLASS_0) {
            // It's a storable message and there's no storage available.  Bail.
            // (See TS 23.038 for a description of class 0 messages.)
            return Intents.RESULT_SMS_OUT_OF_MEMORY;
        }

        return dispatchNormalMessage(smsb, smsSource);
    }

    private void updateMessageWaitingIndicator(int voicemailCount) {
        // range check
        if (voicemailCount < 0) {
            voicemailCount = -1;
        } else if (voicemailCount > 0xff) {
            // TS 23.040 9.2.3.24.2
            // "The value 255 shall be taken to mean 255 or greater"
            voicemailCount = 0xff;
        }
        // update voice mail count in Phone
        mPhone.setVoiceMessageCount(voicemailCount);
    }

    /**
     * Send an acknowledge message.
     *
     * @param success indicates that last message was successfully received.
     * @param result result code indicating any error
     * @param response callback message sent when operation completes.
     */
    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
    @Override
    protected void acknowledgeLastIncomingSms(boolean success, int result, Message response) {
        mPhone.mCi.acknowledgeLastIncomingGsmSms(success, resultToCause(result), response);
    }

    /**
     * Convert Android result code to 3GPP SMS failure cause.
     *
     * @param rc the Android SMS intent result value
     * @return 0 for success, or a 3GPP SMS failure cause value
     */
    private static int resultToCause(int rc) {
        switch (rc) {
            case Activity.RESULT_OK:
            case Intents.RESULT_SMS_HANDLED:
                // Cause code is ignored on success.
                return 0;
            case Intents.RESULT_SMS_OUT_OF_MEMORY:
                return CommandsInterface.GSM_SMS_FAIL_CAUSE_MEMORY_CAPACITY_EXCEEDED;
            case Intents.RESULT_SMS_GENERIC_ERROR:
            default:
                return CommandsInterface.GSM_SMS_FAIL_CAUSE_UNSPECIFIED_ERROR;
        }
    }

    /**
     * Add SMS of type 0 to metrics.
     */
    private void addSmsTypeZeroToMetrics(@SmsSource int smsSource) {
        mMetrics.writeIncomingSmsTypeZero(mPhone.getPhoneId(),
                android.telephony.SmsMessage.FORMAT_3GPP);
        mPhone.getSmsStats().onIncomingSmsTypeZero(smsSource);
    }

    /**
     * Add voicemail indication SMS 0 to metrics.
     */
    private void addVoicemailSmsToMetrics(@SmsSource int smsSource) {
        mMetrics.writeIncomingVoiceMailSms(mPhone.getPhoneId(),
                android.telephony.SmsMessage.FORMAT_3GPP);
        mPhone.getSmsStats().onIncomingSmsVoicemail(false /* is3gpp2 */, smsSource);
    }
}