xref: /frameworks/opt/telephony/src/java/com/android/internal/telephony/SMSDispatcher.java

/*
 * Copyright (C) 2006 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;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.PendingIntent;
import android.app.PendingIntent.CanceledException;
import android.content.ContentResolver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.res.Resources;
import android.database.ContentObserver;
import android.os.AsyncResult;
import android.os.Binder;
import android.os.Handler;
import android.os.Message;
import android.os.SystemProperties;
import android.provider.Settings;
import android.telephony.PhoneNumberUtils;
import android.telephony.Rlog;
import android.telephony.ServiceState;
import android.telephony.TelephonyManager;
import android.text.Html;
import android.text.Spanned;
import android.util.EventLog;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.TextView;

import com.android.internal.R;
import com.android.internal.telephony.GsmAlphabet.TextEncodingDetails;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Random;
import java.util.concurrent.atomic.AtomicInteger;

import static android.telephony.SmsManager.RESULT_ERROR_FDN_CHECK_FAILURE;
import static android.telephony.SmsManager.RESULT_ERROR_GENERIC_FAILURE;
import static android.telephony.SmsManager.RESULT_ERROR_LIMIT_EXCEEDED;
import static android.telephony.SmsManager.RESULT_ERROR_NO_SERVICE;
import static android.telephony.SmsManager.RESULT_ERROR_NULL_PDU;
import static android.telephony.SmsManager.RESULT_ERROR_RADIO_OFF;

public abstract class SMSDispatcher extends Handler {
    static final String TAG = "SMSDispatcher";    // accessed from inner class
    static final boolean DBG = false;
    private static final String SEND_NEXT_MSG_EXTRA = "SendNextMsg";

    /** Permission required to send SMS to short codes without user confirmation. */
    private static final String SEND_SMS_NO_CONFIRMATION_PERMISSION =
            "android.permission.SEND_SMS_NO_CONFIRMATION";

    private static final int PREMIUM_RULE_USE_SIM = 1;
    private static final int PREMIUM_RULE_USE_NETWORK = 2;
    private static final int PREMIUM_RULE_USE_BOTH = 3;
    private final AtomicInteger mPremiumSmsRule = new AtomicInteger(PREMIUM_RULE_USE_SIM);
    private final SettingsObserver mSettingsObserver;

    /** SMS send complete. */
    protected static final int EVENT_SEND_SMS_COMPLETE = 2;

    /** Retry sending a previously failed SMS message */
    private static final int EVENT_SEND_RETRY = 3;

    /** Confirmation required for sending a large number of messages. */
    private static final int EVENT_SEND_LIMIT_REACHED_CONFIRMATION = 4;

    /** Send the user confirmed SMS */
    static final int EVENT_SEND_CONFIRMED_SMS = 5;  // accessed from inner class

    /** Don't send SMS (user did not confirm). */
    static final int EVENT_STOP_SENDING = 7;        // accessed from inner class

    /** Confirmation required for third-party apps sending to an SMS short code. */
    private static final int EVENT_CONFIRM_SEND_TO_POSSIBLE_PREMIUM_SHORT_CODE = 8;

    /** Confirmation required for third-party apps sending to an SMS short code. */
    private static final int EVENT_CONFIRM_SEND_TO_PREMIUM_SHORT_CODE = 9;

    /** Handle status report from {@code CdmaInboundSmsHandler}. */
    protected static final int EVENT_HANDLE_STATUS_REPORT = 10;

    protected final Phone mPhone;
    protected final Context mContext;
    protected final ContentResolver mResolver;
    protected final CommandsInterface mCi;
    protected final TelephonyManager mTelephonyManager;

    /** Maximum number of times to retry sending a failed SMS. */
    private static final int MAX_SEND_RETRIES = 3;
    /** Delay before next send attempt on a failed SMS, in milliseconds. */
    private static final int SEND_RETRY_DELAY = 2000;
    /** single part SMS */
    private static final int SINGLE_PART_SMS = 1;
    /** Message sending queue limit */
    private static final int MO_MSG_QUEUE_LIMIT = 5;

    /**
     * Message reference for a CONCATENATED_8_BIT_REFERENCE or
     * CONCATENATED_16_BIT_REFERENCE message set.  Should be
     * incremented for each set of concatenated messages.
     * Static field shared by all dispatcher objects.
     */
    private static int sConcatenatedRef = new Random().nextInt(256);

    /** Outgoing message counter. Shared by all dispatchers. */
    private final SmsUsageMonitor mUsageMonitor;

    /** Number of outgoing SmsTrackers waiting for user confirmation. */
    private int mPendingTrackerCount;

    /* Flags indicating whether the current device allows sms service */
    protected boolean mSmsCapable = true;
    protected boolean mSmsSendDisabled;

    protected int mRemainingMessages = -1;

    protected static int getNextConcatenatedRef() {
        sConcatenatedRef += 1;
        return sConcatenatedRef;
    }

    /**
     * Create a new SMS dispatcher.
     * @param phone the Phone to use
     * @param usageMonitor the SmsUsageMonitor to use
     */
    protected SMSDispatcher(PhoneBase phone, SmsUsageMonitor usageMonitor) {
        mPhone = phone;
        mContext = phone.getContext();
        mResolver = mContext.getContentResolver();
        mCi = phone.mCi;
        mUsageMonitor = usageMonitor;
        mTelephonyManager = (TelephonyManager) mContext.getSystemService(Context.TELEPHONY_SERVICE);
        mSettingsObserver = new SettingsObserver(this, mPremiumSmsRule, mContext);
        mContext.getContentResolver().registerContentObserver(Settings.Global.getUriFor(
                Settings.Global.SMS_SHORT_CODE_RULE), false, mSettingsObserver);

        mSmsCapable = mContext.getResources().getBoolean(
                com.android.internal.R.bool.config_sms_capable);
        mSmsSendDisabled = !SystemProperties.getBoolean(
                                TelephonyProperties.PROPERTY_SMS_SEND, mSmsCapable);
        Rlog.d(TAG, "SMSDispatcher: ctor mSmsCapable=" + mSmsCapable + " format=" + getFormat()
                + " mSmsSendDisabled=" + mSmsSendDisabled);
    }

    /**
     * Observe the secure setting for updated premium sms determination rules
     */
    private static class SettingsObserver extends ContentObserver {
        private final AtomicInteger mPremiumSmsRule;
        private final Context mContext;
        SettingsObserver(Handler handler, AtomicInteger premiumSmsRule, Context context) {
            super(handler);
            mPremiumSmsRule = premiumSmsRule;
            mContext = context;
            onChange(false); // load initial value;
        }

        @Override
        public void onChange(boolean selfChange) {
            mPremiumSmsRule.set(Settings.Global.getInt(mContext.getContentResolver(),
                    Settings.Global.SMS_SHORT_CODE_RULE, PREMIUM_RULE_USE_SIM));
        }
    }

    /** Unregister for incoming SMS events. */
    public void dispose() {
        mContext.getContentResolver().unregisterContentObserver(mSettingsObserver);
    }

    /**
     * The format of the message PDU in the associated broadcast intent.
     * This will be either "3gpp" for GSM/UMTS/LTE messages in 3GPP format
     * or "3gpp2" for CDMA/LTE messages in 3GPP2 format.
     *
     * Note: All applications which handle incoming SMS messages by processing the
     * SMS_RECEIVED_ACTION broadcast intent MUST pass the "format" extra from the intent
     * into the new methods in {@link android.telephony.SmsMessage} which take an
     * extra format parameter. This is required in order to correctly decode the PDU on
     * devices which require support for both 3GPP and 3GPP2 formats at the same time,
     * such as CDMA/LTE devices and GSM/CDMA world phones.
     *
     * @return the format of the message PDU
     */
    protected abstract String getFormat();

    /**
     * Pass the Message object to subclass to handle. Currently used to pass CDMA status reports
     * from {@link com.android.internal.telephony.cdma.CdmaInboundSmsHandler}.
     * @param o the SmsMessage containing the status report
     */
    protected void handleStatusReport(Object o) {
        Rlog.d(TAG, "handleStatusReport() called with no subclass.");
    }

    /* TODO: Need to figure out how to keep track of status report routing in a
     *       persistent manner. If the phone process restarts (reboot or crash),
     *       we will lose this list and any status reports that come in after
     *       will be dropped.
     */
    /** Sent messages awaiting a delivery status report. */
    protected final ArrayList<SmsTracker> deliveryPendingList = new ArrayList<SmsTracker>();

    /**
     * Handles events coming from the phone stack. Overridden from handler.
     *
     * @param msg the message to handle
     */
    @Override
    public void handleMessage(Message msg) {
        switch (msg.what) {
        case EVENT_SEND_SMS_COMPLETE:
            // An outbound SMS has been successfully transferred, or failed.
            handleSendComplete((AsyncResult) msg.obj);
            break;

        case EVENT_SEND_RETRY:
            sendSms((SmsTracker) msg.obj);
            break;

        case EVENT_SEND_LIMIT_REACHED_CONFIRMATION:
            handleReachSentLimit((SmsTracker)(msg.obj));
            break;

        case EVENT_CONFIRM_SEND_TO_POSSIBLE_PREMIUM_SHORT_CODE:
            handleConfirmShortCode(false, (SmsTracker)(msg.obj));
            break;

        case EVENT_CONFIRM_SEND_TO_PREMIUM_SHORT_CODE:
            handleConfirmShortCode(true, (SmsTracker)(msg.obj));
            break;

        case EVENT_SEND_CONFIRMED_SMS:
        {
            SmsTracker tracker = (SmsTracker) msg.obj;
            if (tracker.isMultipart()) {
                sendMultipartSms(tracker);
            } else {
                sendSms(tracker);
            }
            mPendingTrackerCount--;
            break;
        }

        case EVENT_STOP_SENDING:
        {
            SmsTracker tracker = (SmsTracker) msg.obj;
            if (tracker.mSentIntent != null) {
                try {
                    tracker.mSentIntent.send(RESULT_ERROR_LIMIT_EXCEEDED);
                } catch (CanceledException ex) {
                    Rlog.e(TAG, "failed to send RESULT_ERROR_LIMIT_EXCEEDED");
                }
            }
            mPendingTrackerCount--;
            break;
        }

        case EVENT_HANDLE_STATUS_REPORT:
            handleStatusReport(msg.obj);
            break;

        default:
            Rlog.e(TAG, "handleMessage() ignoring message of unexpected type " + msg.what);
        }
    }

    /**
     * Called when SMS send completes. Broadcasts a sentIntent on success.
     * On failure, either sets up retries or broadcasts a sentIntent with
     * the failure in the result code.
     *
     * @param ar AsyncResult passed into the message handler.  ar.result should
     *           an SmsResponse instance if send was successful.  ar.userObj
     *           should be an SmsTracker instance.
     */
    protected void handleSendComplete(AsyncResult ar) {
        SmsTracker tracker = (SmsTracker) ar.userObj;
        PendingIntent sentIntent = tracker.mSentIntent;

        if (ar.result != null) {
            tracker.mMessageRef = ((SmsResponse)ar.result).mMessageRef;
        } else {
            Rlog.d(TAG, "SmsResponse was null");
        }

        if (ar.exception == null) {
            if (DBG) Rlog.d(TAG, "SMS send complete. Broadcasting intent: " + sentIntent);

            if (tracker.mDeliveryIntent != null) {
                // Expecting a status report.  Add it to the list.
                deliveryPendingList.add(tracker);
            }

            if (sentIntent != null) {
                try {
                    if (mRemainingMessages > -1) {
                        mRemainingMessages--;
                    }

                    if (mRemainingMessages == 0) {
                        Intent sendNext = new Intent();
                        sendNext.putExtra(SEND_NEXT_MSG_EXTRA, true);
                        sentIntent.send(mContext, Activity.RESULT_OK, sendNext);
                    } else {
                        sentIntent.send(Activity.RESULT_OK);
                    }
                } catch (CanceledException ex) {}
            }
        } else {
            if (DBG) Rlog.d(TAG, "SMS send failed");

            int ss = mPhone.getServiceState().getState();

            if (ss != ServiceState.STATE_IN_SERVICE) {
                handleNotInService(ss, tracker.mSentIntent);
            } else if ((((CommandException)(ar.exception)).getCommandError()
                    == CommandException.Error.SMS_FAIL_RETRY) &&
                   tracker.mRetryCount < MAX_SEND_RETRIES) {
                // Retry after a delay if needed.
                // TODO: According to TS 23.040, 9.2.3.6, we should resend
                //       with the same TP-MR as the failed message, and
                //       TP-RD set to 1.  However, we don't have a means of
                //       knowing the MR for the failed message (EF_SMSstatus
                //       may or may not have the MR corresponding to this
                //       message, depending on the failure).  Also, in some
                //       implementations this retry is handled by the baseband.
                tracker.mRetryCount++;
                Message retryMsg = obtainMessage(EVENT_SEND_RETRY, tracker);
                sendMessageDelayed(retryMsg, SEND_RETRY_DELAY);
            } else if (tracker.mSentIntent != null) {
                int error = RESULT_ERROR_GENERIC_FAILURE;

                if (((CommandException)(ar.exception)).getCommandError()
                        == CommandException.Error.FDN_CHECK_FAILURE) {
                    error = RESULT_ERROR_FDN_CHECK_FAILURE;
                }
                // Done retrying; return an error to the app.
                try {
                    Intent fillIn = new Intent();
                    if (ar.result != null) {
                        fillIn.putExtra("errorCode", ((SmsResponse)ar.result).mErrorCode);
                    }
                    if (mRemainingMessages > -1) {
                        mRemainingMessages--;
                    }

                    if (mRemainingMessages == 0) {
                        fillIn.putExtra(SEND_NEXT_MSG_EXTRA, true);
                    }

                    tracker.mSentIntent.send(mContext, error, fillIn);
                } catch (CanceledException ex) {}
            }
        }
    }

    /**
     * Handles outbound message when the phone is not in service.
     *
     * @param ss     Current service state.  Valid values are:
     *                  OUT_OF_SERVICE
     *                  EMERGENCY_ONLY
     *                  POWER_OFF
     * @param sentIntent the PendingIntent to send the error to
     */
    protected static void handleNotInService(int ss, PendingIntent sentIntent) {
        if (sentIntent != null) {
            try {
                if (ss == ServiceState.STATE_POWER_OFF) {
                    sentIntent.send(RESULT_ERROR_RADIO_OFF);
                } else {
                    sentIntent.send(RESULT_ERROR_NO_SERVICE);
                }
            } catch (CanceledException ex) {}
        }
    }

    /**
     * Send a data based SMS to a specific application port.
     *
     * @param destAddr the address to send the message to
     * @param scAddr is the service center address or null to use
     *  the current default SMSC
     * @param destPort the port to deliver the message to
     * @param data the body of the message to send
     * @param sentIntent if not NULL this <code>PendingIntent</code> is
     *  broadcast when the message is successfully sent, or failed.
     *  The result code will be <code>Activity.RESULT_OK<code> for success,
     *  or one of these errors:<br>
     *  <code>RESULT_ERROR_GENERIC_FAILURE</code><br>
     *  <code>RESULT_ERROR_RADIO_OFF</code><br>
     *  <code>RESULT_ERROR_NULL_PDU</code><br>
     *  <code>RESULT_ERROR_NO_SERVICE</code><br>.
     *  For <code>RESULT_ERROR_GENERIC_FAILURE</code> the sentIntent may include
     *  the extra "errorCode" containing a radio technology specific value,
     *  generally only useful for troubleshooting.<br>
     *  The per-application based SMS control checks sentIntent. If sentIntent
     *  is NULL the caller will be checked against all unknown applications,
     *  which cause smaller number of SMS to be sent in checking period.
     * @param deliveryIntent if not NULL this <code>PendingIntent</code> is
     *  broadcast when the message is delivered to the recipient.  The
     *  raw pdu of the status report is in the extended data ("pdu").
     */
    protected abstract void sendData(String destAddr, String scAddr, int destPort,
            byte[] data, PendingIntent sentIntent, PendingIntent deliveryIntent);

    /**
     * Send a text based SMS.
     *
     * @param destAddr the address to send the message to
     * @param scAddr is the service center address or null to use
     *  the current default SMSC
     * @param text the body of the message to send
     * @param sentIntent if not NULL this <code>PendingIntent</code> is
     *  broadcast when the message is successfully sent, or failed.
     *  The result code will be <code>Activity.RESULT_OK<code> for success,
     *  or one of these errors:<br>
     *  <code>RESULT_ERROR_GENERIC_FAILURE</code><br>
     *  <code>RESULT_ERROR_RADIO_OFF</code><br>
     *  <code>RESULT_ERROR_NULL_PDU</code><br>
     *  <code>RESULT_ERROR_NO_SERVICE</code><br>.
     *  For <code>RESULT_ERROR_GENERIC_FAILURE</code> the sentIntent may include
     *  the extra "errorCode" containing a radio technology specific value,
     *  generally only useful for troubleshooting.<br>
     *  The per-application based SMS control checks sentIntent. If sentIntent
     *  is NULL the caller will be checked against all unknown applications,
     *  which cause smaller number of SMS to be sent in checking period.
     * @param deliveryIntent if not NULL this <code>PendingIntent</code> is
     *  broadcast when the message is delivered to the recipient.  The
     *  raw pdu of the status report is in the extended data ("pdu").
     */
    protected abstract void sendText(String destAddr, String scAddr,
            String text, PendingIntent sentIntent, PendingIntent deliveryIntent);

    /**
     * Calculate the number of septets needed to encode the message.
     *
     * @param messageBody the message to encode
     * @param use7bitOnly ignore (but still count) illegal characters if true
     * @return TextEncodingDetails
     */
    protected abstract TextEncodingDetails calculateLength(CharSequence messageBody,
            boolean use7bitOnly);

    /**
     * Send a multi-part text based SMS.
     *
     * @param destAddr the address to send the message to
     * @param scAddr is the service center address or null to use
     *   the current default SMSC
     * @param parts an <code>ArrayList</code> of strings that, in order,
     *   comprise the original message
     * @param sentIntents if not null, an <code>ArrayList</code> of
     *   <code>PendingIntent</code>s (one for each message part) that is
     *   broadcast when the corresponding message part has been sent.
     *   The result code will be <code>Activity.RESULT_OK<code> for success,
     *   or one of these errors:
     *   <code>RESULT_ERROR_GENERIC_FAILURE</code>
     *   <code>RESULT_ERROR_RADIO_OFF</code>
     *   <code>RESULT_ERROR_NULL_PDU</code>
     *   <code>RESULT_ERROR_NO_SERVICE</code>.
     *  The per-application based SMS control checks sentIntent. If sentIntent
     *  is NULL the caller will be checked against all unknown applications,
     *  which cause smaller number of SMS to be sent in checking period.
     * @param deliveryIntents if not null, an <code>ArrayList</code> of
     *   <code>PendingIntent</code>s (one for each message part) that is
     *   broadcast when the corresponding message part has been delivered
     *   to the recipient.  The raw pdu of the status report is in the
     *   extended data ("pdu").
     */
    protected void sendMultipartText(String destAddr, String scAddr,
            ArrayList<String> parts, ArrayList<PendingIntent> sentIntents,
            ArrayList<PendingIntent> deliveryIntents) {

        int refNumber = getNextConcatenatedRef() & 0x00FF;
        int msgCount = parts.size();
        int encoding = SmsConstants.ENCODING_UNKNOWN;

        mRemainingMessages = msgCount;

        TextEncodingDetails[] encodingForParts = new TextEncodingDetails[msgCount];
        for (int i = 0; i < msgCount; i++) {
            TextEncodingDetails details = calculateLength(parts.get(i), false);
            if (encoding != details.codeUnitSize
                    && (encoding == SmsConstants.ENCODING_UNKNOWN
                            || encoding == SmsConstants.ENCODING_7BIT)) {
                encoding = details.codeUnitSize;
            }
            encodingForParts[i] = details;
        }

        for (int i = 0; i < msgCount; i++) {
            SmsHeader.ConcatRef concatRef = new SmsHeader.ConcatRef();
            concatRef.refNumber = refNumber;
            concatRef.seqNumber = i + 1;  // 1-based sequence
            concatRef.msgCount = msgCount;
            // TODO: We currently set this to true since our messaging app will never
            // send more than 255 parts (it converts the message to MMS well before that).
            // However, we should support 3rd party messaging apps that might need 16-bit
            // references
            // Note:  It's not sufficient to just flip this bit to true; it will have
            // ripple effects (several calculations assume 8-bit ref).
            concatRef.isEightBits = true;
            SmsHeader smsHeader = new SmsHeader();
            smsHeader.concatRef = concatRef;

            // Set the national language tables for 3GPP 7-bit encoding, if enabled.
            if (encoding == SmsConstants.ENCODING_7BIT) {
                smsHeader.languageTable = encodingForParts[i].languageTable;
                smsHeader.languageShiftTable = encodingForParts[i].languageShiftTable;
            }

            PendingIntent sentIntent = null;
            if (sentIntents != null && sentIntents.size() > i) {
                sentIntent = sentIntents.get(i);
            }

            PendingIntent deliveryIntent = null;
            if (deliveryIntents != null && deliveryIntents.size() > i) {
                deliveryIntent = deliveryIntents.get(i);
            }

            sendNewSubmitPdu(destAddr, scAddr, parts.get(i), smsHeader, encoding,
                    sentIntent, deliveryIntent, (i == (msgCount - 1)));
        }

    }

    /**
     * Create a new SubmitPdu and send it.
     */
    protected abstract void sendNewSubmitPdu(String destinationAddress, String scAddress,
            String message, SmsHeader smsHeader, int encoding,
            PendingIntent sentIntent, PendingIntent deliveryIntent, boolean lastPart);

    /**
     * Send a SMS
     *
     * @param smsc the SMSC to send the message through, or NULL for the
     *  default SMSC
     * @param pdu the raw PDU to send
     * @param sentIntent if not NULL this <code>Intent</code> is
     *  broadcast when the message is successfully sent, or failed.
     *  The result code will be <code>Activity.RESULT_OK<code> for success,
     *  or one of these errors:
     *  <code>RESULT_ERROR_GENERIC_FAILURE</code>
     *  <code>RESULT_ERROR_RADIO_OFF</code>
     *  <code>RESULT_ERROR_NULL_PDU</code>
     *  <code>RESULT_ERROR_NO_SERVICE</code>.
     *  The per-application based SMS control checks sentIntent. If sentIntent
     *  is NULL the caller will be checked against all unknown applications,
     *  which cause smaller number of SMS to be sent in checking period.
     * @param deliveryIntent if not NULL this <code>Intent</code> is
     *  broadcast when the message is delivered to the recipient.  The
     *  raw pdu of the status report is in the extended data ("pdu").
     * @param destAddr the destination phone number (for short code confirmation)
     */
    protected void sendRawPdu(byte[] smsc, byte[] pdu, PendingIntent sentIntent,
            PendingIntent deliveryIntent, String destAddr) {
        if (mSmsSendDisabled) {
            if (sentIntent != null) {
                try {
                    sentIntent.send(RESULT_ERROR_NO_SERVICE);
                } catch (CanceledException ex) {}
            }
            Rlog.d(TAG, "Device does not support sending sms.");
            return;
        }

        if (pdu == null) {
            if (sentIntent != null) {
                try {
                    sentIntent.send(RESULT_ERROR_NULL_PDU);
                } catch (CanceledException ex) {}
            }
            return;
        }

        HashMap<String, Object> map = new HashMap<String, Object>();
        map.put("smsc", smsc);
        map.put("pdu", pdu);

        // Get calling app package name via UID from Binder call
        PackageManager pm = mContext.getPackageManager();
        String[] packageNames = pm.getPackagesForUid(Binder.getCallingUid());

        if (packageNames == null || packageNames.length == 0) {
            // Refuse to send SMS if we can't get the calling package name.
            Rlog.e(TAG, "Can't get calling app package name: refusing to send SMS");
            if (sentIntent != null) {
                try {
                    sentIntent.send(RESULT_ERROR_GENERIC_FAILURE);
                } catch (CanceledException ex) {
                    Rlog.e(TAG, "failed to send error result");
                }
            }
            return;
        }

        // Get package info via packagemanager
        PackageInfo appInfo;
        try {
            // XXX this is lossy- apps can share a UID
            appInfo = pm.getPackageInfo(packageNames[0], PackageManager.GET_SIGNATURES);
        } catch (PackageManager.NameNotFoundException e) {
            Rlog.e(TAG, "Can't get calling app package info: refusing to send SMS");
            if (sentIntent != null) {
                try {
                    sentIntent.send(RESULT_ERROR_GENERIC_FAILURE);
                } catch (CanceledException ex) {
                    Rlog.e(TAG, "failed to send error result");
                }
            }
            return;
        }

        // Strip non-digits from destination phone number before checking for short codes
        // and before displaying the number to the user if confirmation is required.
        SmsTracker tracker = new SmsTracker(map, sentIntent, deliveryIntent, appInfo,
                PhoneNumberUtils.extractNetworkPortion(destAddr));

        // checkDestination() returns true if the destination is not a premium short code or the
        // sending app is approved to send to short codes. Otherwise, a message is sent to our
        // handler with the SmsTracker to request user confirmation before sending.
        if (checkDestination(tracker)) {
            // check for excessive outgoing SMS usage by this app
            if (!mUsageMonitor.check(appInfo.packageName, SINGLE_PART_SMS)) {
                sendMessage(obtainMessage(EVENT_SEND_LIMIT_REACHED_CONFIRMATION, tracker));
                return;
            }

            int ss = mPhone.getServiceState().getState();

            if (ss != ServiceState.STATE_IN_SERVICE) {
                handleNotInService(ss, tracker.mSentIntent);
            } else {
                sendSms(tracker);
            }
        }
    }

    /**
     * Check if destination is a potential premium short code and sender is not pre-approved to
     * send to short codes.
     *
     * @param tracker the tracker for the SMS to send
     * @return true if the destination is approved; false if user confirmation event was sent
     */
    boolean checkDestination(SmsTracker tracker) {
        if (mContext.checkCallingOrSelfPermission(SEND_SMS_NO_CONFIRMATION_PERMISSION)
                == PackageManager.PERMISSION_GRANTED) {
            return true;            // app is pre-approved to send to short codes
        } else {
            int rule = mPremiumSmsRule.get();
            int smsCategory = SmsUsageMonitor.CATEGORY_NOT_SHORT_CODE;
            if (rule == PREMIUM_RULE_USE_SIM || rule == PREMIUM_RULE_USE_BOTH) {
                String simCountryIso = mTelephonyManager.getSimCountryIso();
                if (simCountryIso == null || simCountryIso.length() != 2) {
                    Rlog.e(TAG, "Can't get SIM country Iso: trying network country Iso");
                    simCountryIso = mTelephonyManager.getNetworkCountryIso();
                }

                smsCategory = mUsageMonitor.checkDestination(tracker.mDestAddress, simCountryIso);
            }
            if (rule == PREMIUM_RULE_USE_NETWORK || rule == PREMIUM_RULE_USE_BOTH) {
                String networkCountryIso = mTelephonyManager.getNetworkCountryIso();
                if (networkCountryIso == null || networkCountryIso.length() != 2) {
                    Rlog.e(TAG, "Can't get Network country Iso: trying SIM country Iso");
                    networkCountryIso = mTelephonyManager.getSimCountryIso();
                }

                smsCategory = SmsUsageMonitor.mergeShortCodeCategories(smsCategory,
                        mUsageMonitor.checkDestination(tracker.mDestAddress, networkCountryIso));
            }

            if (smsCategory == SmsUsageMonitor.CATEGORY_NOT_SHORT_CODE
                    || smsCategory == SmsUsageMonitor.CATEGORY_FREE_SHORT_CODE
                    || smsCategory == SmsUsageMonitor.CATEGORY_STANDARD_SHORT_CODE) {
                return true;    // not a premium short code
            }

            // Wait for user confirmation unless the user has set permission to always allow/deny
            int premiumSmsPermission = mUsageMonitor.getPremiumSmsPermission(
                    tracker.mAppInfo.packageName);
            if (premiumSmsPermission == SmsUsageMonitor.PREMIUM_SMS_PERMISSION_UNKNOWN) {
                // First time trying to send to premium SMS.
                premiumSmsPermission = SmsUsageMonitor.PREMIUM_SMS_PERMISSION_ASK_USER;
            }

            switch (premiumSmsPermission) {
                case SmsUsageMonitor.PREMIUM_SMS_PERMISSION_ALWAYS_ALLOW:
                    Rlog.d(TAG, "User approved this app to send to premium SMS");
                    return true;

                case SmsUsageMonitor.PREMIUM_SMS_PERMISSION_NEVER_ALLOW:
                    Rlog.w(TAG, "User denied this app from sending to premium SMS");
                    sendMessage(obtainMessage(EVENT_STOP_SENDING, tracker));
                    return false;   // reject this message

                case SmsUsageMonitor.PREMIUM_SMS_PERMISSION_ASK_USER:
                default:
                    int event;
                    if (smsCategory == SmsUsageMonitor.CATEGORY_POSSIBLE_PREMIUM_SHORT_CODE) {
                        event = EVENT_CONFIRM_SEND_TO_POSSIBLE_PREMIUM_SHORT_CODE;
                    } else {
                        event = EVENT_CONFIRM_SEND_TO_PREMIUM_SHORT_CODE;
                    }
                    sendMessage(obtainMessage(event, tracker));
                    return false;   // wait for user confirmation
            }
        }
    }

    /**
     * Deny sending an SMS if the outgoing queue limit is reached. Used when the message
     * must be confirmed by the user due to excessive usage or potential premium SMS detected.
     * @param tracker the SmsTracker for the message to send
     * @return true if the message was denied; false to continue with send confirmation
     */
    private boolean denyIfQueueLimitReached(SmsTracker tracker) {
        if (mPendingTrackerCount >= MO_MSG_QUEUE_LIMIT) {
            // Deny sending message when the queue limit is reached.
            try {
                if (tracker.mSentIntent != null) {
                    tracker.mSentIntent.send(RESULT_ERROR_LIMIT_EXCEEDED);
                }
            } catch (CanceledException ex) {
                Rlog.e(TAG, "failed to send back RESULT_ERROR_LIMIT_EXCEEDED");
            }
            return true;
        }
        mPendingTrackerCount++;
        return false;
    }

    /**
     * Returns the label for the specified app package name.
     * @param appPackage the package name of the app requesting to send an SMS
     * @return the label for the specified app, or the package name if getApplicationInfo() fails
     */
    private CharSequence getAppLabel(String appPackage) {
        PackageManager pm = mContext.getPackageManager();
        try {
            ApplicationInfo appInfo = pm.getApplicationInfo(appPackage, 0);
            return appInfo.loadLabel(pm);
        } catch (PackageManager.NameNotFoundException e) {
            Rlog.e(TAG, "PackageManager Name Not Found for package " + appPackage);
            return appPackage;  // fall back to package name if we can't get app label
        }
    }

    /**
     * Post an alert when SMS needs confirmation due to excessive usage.
     * @param tracker an SmsTracker for the current message.
     */
    protected void handleReachSentLimit(SmsTracker tracker) {
        if (denyIfQueueLimitReached(tracker)) {
            return;     // queue limit reached; error was returned to caller
        }

        CharSequence appLabel = getAppLabel(tracker.mAppInfo.packageName);
        Resources r = Resources.getSystem();
        Spanned messageText = Html.fromHtml(r.getString(R.string.sms_control_message, appLabel));

        ConfirmDialogListener listener = new ConfirmDialogListener(tracker, null);

        AlertDialog d = new AlertDialog.Builder(mContext)
                .setTitle(R.string.sms_control_title)
                .setIcon(R.drawable.stat_sys_warning)
                .setMessage(messageText)
                .setPositiveButton(r.getString(R.string.sms_control_yes), listener)
                .setNegativeButton(r.getString(R.string.sms_control_no), listener)
                .setOnCancelListener(listener)
                .create();

        d.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
        d.show();
    }

    /**
     * Post an alert for user confirmation when sending to a potential short code.
     * @param isPremium true if the destination is known to be a premium short code
     * @param tracker the SmsTracker for the current message.
     */
    protected void handleConfirmShortCode(boolean isPremium, SmsTracker tracker) {
        if (denyIfQueueLimitReached(tracker)) {
            return;     // queue limit reached; error was returned to caller
        }

        int detailsId;
        if (isPremium) {
            detailsId = R.string.sms_premium_short_code_details;
        } else {
            detailsId = R.string.sms_short_code_details;
        }

        CharSequence appLabel = getAppLabel(tracker.mAppInfo.packageName);
        Resources r = Resources.getSystem();
        Spanned messageText = Html.fromHtml(r.getString(R.string.sms_short_code_confirm_message,
                appLabel, tracker.mDestAddress));

        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(
                Context.LAYOUT_INFLATER_SERVICE);
        View layout = inflater.inflate(R.layout.sms_short_code_confirmation_dialog, null);

        ConfirmDialogListener listener = new ConfirmDialogListener(tracker,
                (TextView)layout.findViewById(R.id.sms_short_code_remember_undo_instruction));


        TextView messageView = (TextView) layout.findViewById(R.id.sms_short_code_confirm_message);
        messageView.setText(messageText);

        ViewGroup detailsLayout = (ViewGroup) layout.findViewById(
                R.id.sms_short_code_detail_layout);
        TextView detailsView = (TextView) detailsLayout.findViewById(
                R.id.sms_short_code_detail_message);
        detailsView.setText(detailsId);

        CheckBox rememberChoice = (CheckBox) layout.findViewById(
                R.id.sms_short_code_remember_choice_checkbox);
        rememberChoice.setOnCheckedChangeListener(listener);

        AlertDialog d = new AlertDialog.Builder(mContext)
                .setView(layout)
                .setPositiveButton(r.getString(R.string.sms_short_code_confirm_allow), listener)
                .setNegativeButton(r.getString(R.string.sms_short_code_confirm_deny), listener)
                .setOnCancelListener(listener)
                .create();

        d.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
        d.show();

        listener.setPositiveButton(d.getButton(DialogInterface.BUTTON_POSITIVE));
        listener.setNegativeButton(d.getButton(DialogInterface.BUTTON_NEGATIVE));
    }

    /**
     * Returns the premium SMS permission for the specified package. If the package has never
     * been seen before, the default {@link SmsUsageMonitor#PREMIUM_SMS_PERMISSION_ASK_USER}
     * will be returned.
     * @param packageName the name of the package to query permission
     * @return one of {@link SmsUsageMonitor#PREMIUM_SMS_PERMISSION_UNKNOWN},
     *  {@link SmsUsageMonitor#PREMIUM_SMS_PERMISSION_ASK_USER},
     *  {@link SmsUsageMonitor#PREMIUM_SMS_PERMISSION_NEVER_ALLOW}, or
     *  {@link SmsUsageMonitor#PREMIUM_SMS_PERMISSION_ALWAYS_ALLOW}
     */
    public int getPremiumSmsPermission(String packageName) {
        return mUsageMonitor.getPremiumSmsPermission(packageName);
    }

    /**
     * Sets the premium SMS permission for the specified package and save the value asynchronously
     * to persistent storage.
     * @param packageName the name of the package to set permission
     * @param permission one of {@link SmsUsageMonitor#PREMIUM_SMS_PERMISSION_ASK_USER},
     *  {@link SmsUsageMonitor#PREMIUM_SMS_PERMISSION_NEVER_ALLOW}, or
     *  {@link SmsUsageMonitor#PREMIUM_SMS_PERMISSION_ALWAYS_ALLOW}
     */
    public void setPremiumSmsPermission(String packageName, int permission) {
        mUsageMonitor.setPremiumSmsPermission(packageName, permission);
    }

    /**
     * Send the message along to the radio.
     *
     * @param tracker holds the SMS message to send
     */
    protected abstract void sendSms(SmsTracker tracker);

    /**
     * Send the multi-part SMS based on multipart Sms tracker
     *
     * @param tracker holds the multipart Sms tracker ready to be sent
     */
    private void sendMultipartSms(SmsTracker tracker) {
        ArrayList<String> parts;
        ArrayList<PendingIntent> sentIntents;
        ArrayList<PendingIntent> deliveryIntents;

        HashMap<String, Object> map = tracker.mData;

        String destinationAddress = (String) map.get("destination");
        String scAddress = (String) map.get("scaddress");

        parts = (ArrayList<String>) map.get("parts");
        sentIntents = (ArrayList<PendingIntent>) map.get("sentIntents");
        deliveryIntents = (ArrayList<PendingIntent>) map.get("deliveryIntents");

        // check if in service
        int ss = mPhone.getServiceState().getState();
        if (ss != ServiceState.STATE_IN_SERVICE) {
            for (int i = 0, count = parts.size(); i < count; i++) {
                PendingIntent sentIntent = null;
                if (sentIntents != null && sentIntents.size() > i) {
                    sentIntent = sentIntents.get(i);
                }
                handleNotInService(ss, sentIntent);
            }
            return;
        }

        sendMultipartText(destinationAddress, scAddress, parts, sentIntents, deliveryIntents);
    }

    /**
     * Keeps track of an SMS that has been sent to the RIL, until it has
     * successfully been sent, or we're done trying.
     */
    protected static final class SmsTracker {
        // fields need to be public for derived SmsDispatchers
        public final HashMap<String, Object> mData;
        public int mRetryCount;
        public int mMessageRef;

        public final PendingIntent mSentIntent;
        public final PendingIntent mDeliveryIntent;

        public final PackageInfo mAppInfo;
        public final String mDestAddress;

        public SmsTracker(HashMap<String, Object> data, PendingIntent sentIntent,
                PendingIntent deliveryIntent, PackageInfo appInfo, String destAddr) {
            mData = data;
            mSentIntent = sentIntent;
            mDeliveryIntent = deliveryIntent;
            mRetryCount = 0;
            mAppInfo = appInfo;
            mDestAddress = destAddr;
        }

        /**
         * Returns whether this tracker holds a multi-part SMS.
         * @return true if the tracker holds a multi-part SMS; false otherwise
         */
        boolean isMultipart() {
            HashMap<String, Object> map = mData;
            return map.containsKey("parts");
        }
    }

    /**
     * Dialog listener for SMS confirmation dialog.
     */
    private final class ConfirmDialogListener
            implements DialogInterface.OnClickListener, DialogInterface.OnCancelListener,
            CompoundButton.OnCheckedChangeListener {

        private final SmsTracker mTracker;
        private Button mPositiveButton;
        private Button mNegativeButton;
        private boolean mRememberChoice;    // default is unchecked
        private final TextView mRememberUndoInstruction;

        ConfirmDialogListener(SmsTracker tracker, TextView textView) {
            mTracker = tracker;
            mRememberUndoInstruction = textView;
        }

        void setPositiveButton(Button button) {
            mPositiveButton = button;
        }

        void setNegativeButton(Button button) {
            mNegativeButton = button;
        }

        @Override
        public void onClick(DialogInterface dialog, int which) {
            // Always set the SMS permission so that Settings will show a permission setting
            // for the app (it won't be shown until after the app tries to send to a short code).
            int newSmsPermission = SmsUsageMonitor.PREMIUM_SMS_PERMISSION_ASK_USER;

            if (which == DialogInterface.BUTTON_POSITIVE) {
                Rlog.d(TAG, "CONFIRM sending SMS");
                // XXX this is lossy- apps can have more than one signature
                EventLog.writeEvent(EventLogTags.EXP_DET_SMS_SENT_BY_USER,
                                    mTracker.mAppInfo.signatures[0].toCharsString());
                sendMessage(obtainMessage(EVENT_SEND_CONFIRMED_SMS, mTracker));
                if (mRememberChoice) {
                    newSmsPermission = SmsUsageMonitor.PREMIUM_SMS_PERMISSION_ALWAYS_ALLOW;
                }
            } else if (which == DialogInterface.BUTTON_NEGATIVE) {
                Rlog.d(TAG, "DENY sending SMS");
                // XXX this is lossy- apps can have more than one signature
                EventLog.writeEvent(EventLogTags.EXP_DET_SMS_DENIED_BY_USER,
                                    mTracker.mAppInfo.signatures[0].toCharsString());
                sendMessage(obtainMessage(EVENT_STOP_SENDING, mTracker));
                if (mRememberChoice) {
                    newSmsPermission = SmsUsageMonitor.PREMIUM_SMS_PERMISSION_NEVER_ALLOW;
                }
            }
            setPremiumSmsPermission(mTracker.mAppInfo.packageName, newSmsPermission);
        }

        @Override
        public void onCancel(DialogInterface dialog) {
            Rlog.d(TAG, "dialog dismissed: don't send SMS");
            sendMessage(obtainMessage(EVENT_STOP_SENDING, mTracker));
        }

        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            Rlog.d(TAG, "remember this choice: " + isChecked);
            mRememberChoice = isChecked;
            if (isChecked) {
                mPositiveButton.setText(R.string.sms_short_code_confirm_always_allow);
                mNegativeButton.setText(R.string.sms_short_code_confirm_never_allow);
                if (mRememberUndoInstruction != null) {
                    mRememberUndoInstruction.
                            setText(R.string.sms_short_code_remember_undo_instruction);
                    mRememberUndoInstruction.setPadding(0,0,0,32);
                }
            } else {
                mPositiveButton.setText(R.string.sms_short_code_confirm_allow);
                mNegativeButton.setText(R.string.sms_short_code_confirm_deny);
                if (mRememberUndoInstruction != null) {
                    mRememberUndoInstruction.setText("");
                    mRememberUndoInstruction.setPadding(0,0,0,0);
                }
            }
        }
    }
}