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Merge "Move GsmSmsCbMessage to CBReceiver test app"

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This commit is contained in:
Jack Yu
2020-02-04 17:04:11 +00:00
committed by Gerrit Code Review
parent f8eeac594b 4583717145
commit de1fa3078c
1 changed files with 0 additions and 521 deletions
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telephony/java/com/android/internal/telephony/gsm/GsmSmsCbMessage.java
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/*
* Copyright (C) 2012 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 static android.telephony.SmsCbEtwsInfo.ETWS_WARNING_TYPE_EARTHQUAKE;
import static android.telephony.SmsCbEtwsInfo.ETWS_WARNING_TYPE_EARTHQUAKE_AND_TSUNAMI;
import static android.telephony.SmsCbEtwsInfo.ETWS_WARNING_TYPE_OTHER_EMERGENCY;
import static android.telephony.SmsCbEtwsInfo.ETWS_WARNING_TYPE_TEST_MESSAGE;
import static android.telephony.SmsCbEtwsInfo.ETWS_WARNING_TYPE_TSUNAMI;
import android.annotation.NonNull;
import android.content.Context;
import android.content.res.Resources;
import android.telephony.CbGeoUtils;
import android.telephony.CbGeoUtils.Circle;
import android.telephony.CbGeoUtils.Geometry;
import android.telephony.CbGeoUtils.LatLng;
import android.telephony.CbGeoUtils.Polygon;
import android.telephony.SmsCbLocation;
import android.telephony.SmsCbMessage;
import android.telephony.SubscriptionManager;
import android.util.Pair;
import android.util.Slog;
import com.android.internal.R;
import com.android.internal.telephony.GsmAlphabet;
import com.android.internal.telephony.SmsConstants;
import com.android.internal.telephony.gsm.GsmSmsCbMessage.GeoFencingTriggerMessage.CellBroadcastIdentity;
import com.android.internal.telephony.gsm.SmsCbHeader.DataCodingScheme;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
/**
* Parses a GSM or UMTS format SMS-CB message into an {@link SmsCbMessage} object. The class is
* public because {@link #createSmsCbMessage(SmsCbLocation, byte[][])} is used by some test cases.
*/
public class GsmSmsCbMessage {
private static final String TAG = GsmSmsCbMessage.class.getSimpleName();
private static final char CARRIAGE_RETURN = 0x0d;
private static final int PDU_BODY_PAGE_LENGTH = 82;
/** Utility class with only static methods. */
private GsmSmsCbMessage() { }
/**
* Get built-in ETWS primary messages by category. ETWS primary message does not contain text,
* so we have to show the pre-built messages to the user.
*
* @param context Device context
* @param category ETWS message category defined in SmsCbConstants
* @return ETWS text message in string. Return an empty string if no match.
*/
private static String getEtwsPrimaryMessage(Context context, int category) {
final Resources r = context.getResources();
switch (category) {
case ETWS_WARNING_TYPE_EARTHQUAKE:
return r.getString(R.string.etws_primary_default_message_earthquake);
case ETWS_WARNING_TYPE_TSUNAMI:
return r.getString(R.string.etws_primary_default_message_tsunami);
case ETWS_WARNING_TYPE_EARTHQUAKE_AND_TSUNAMI:
return r.getString(R.string.etws_primary_default_message_earthquake_and_tsunami);
case ETWS_WARNING_TYPE_TEST_MESSAGE:
return r.getString(R.string.etws_primary_default_message_test);
case ETWS_WARNING_TYPE_OTHER_EMERGENCY:
return r.getString(R.string.etws_primary_default_message_others);
default:
return "";
}
}
/**
* Create a new SmsCbMessage object from a header object plus one or more received PDUs.
*
* @param pdus PDU bytes
* @slotIndex slotIndex for which received sms cb message
*/
public static SmsCbMessage createSmsCbMessage(Context context, SmsCbHeader header,
SmsCbLocation location, byte[][] pdus, int slotIndex)
throws IllegalArgumentException {
SubscriptionManager sm = (SubscriptionManager) context.getSystemService(
Context.TELEPHONY_SUBSCRIPTION_SERVICE);
int subId = SubscriptionManager.DEFAULT_SUBSCRIPTION_ID;
int[] subIds = sm.getSubscriptionIds(slotIndex);
if (subIds != null && subIds.length > 0) {
subId = subIds[0];
}
long receivedTimeMillis = System.currentTimeMillis();
if (header.isEtwsPrimaryNotification()) {
// ETSI TS 23.041 ETWS Primary Notification message
// ETWS primary message only contains 4 fields including serial number,
// message identifier, warning type, and warning security information.
// There is no field for the content/text so we get the text from the resources.
return new SmsCbMessage(SmsCbMessage.MESSAGE_FORMAT_3GPP, header.getGeographicalScope(),
header.getSerialNumber(), location, header.getServiceCategory(), null,
getEtwsPrimaryMessage(context, header.getEtwsInfo().getWarningType()),
SmsCbMessage.MESSAGE_PRIORITY_EMERGENCY, header.getEtwsInfo(),
header.getCmasInfo(), 0, null /* geometries */, receivedTimeMillis, slotIndex,
subId);
} else if (header.isUmtsFormat()) {
// UMTS format has only 1 PDU
byte[] pdu = pdus[0];
Pair<String, String> cbData = parseUmtsBody(header, pdu);
String language = cbData.first;
String body = cbData.second;
int priority = header.isEmergencyMessage() ? SmsCbMessage.MESSAGE_PRIORITY_EMERGENCY
: SmsCbMessage.MESSAGE_PRIORITY_NORMAL;
int nrPages = pdu[SmsCbHeader.PDU_HEADER_LENGTH];
int wacDataOffset = SmsCbHeader.PDU_HEADER_LENGTH
+ 1 // number of pages
+ (PDU_BODY_PAGE_LENGTH + 1) * nrPages; // cb data
// Has Warning Area Coordinates information
List<Geometry> geometries = null;
int maximumWaitingTimeSec = 255;
if (pdu.length > wacDataOffset) {
try {
Pair<Integer, List<Geometry>> wac = parseWarningAreaCoordinates(pdu,
wacDataOffset);
maximumWaitingTimeSec = wac.first;
geometries = wac.second;
} catch (Exception ex) {
// Catch the exception here, the message will be considered as having no WAC
// information which means the message will be broadcasted directly.
Slog.e(TAG, "Can't parse warning area coordinates, ex = " + ex.toString());
}
}
return new SmsCbMessage(SmsCbMessage.MESSAGE_FORMAT_3GPP,
header.getGeographicalScope(), header.getSerialNumber(), location,
header.getServiceCategory(), language, body, priority,
header.getEtwsInfo(), header.getCmasInfo(), maximumWaitingTimeSec, geometries,
receivedTimeMillis, slotIndex, subId);
} else {
String language = null;
StringBuilder sb = new StringBuilder();
for (byte[] pdu : pdus) {
Pair<String, String> p = parseGsmBody(header, pdu);
language = p.first;
sb.append(p.second);
}
int priority = header.isEmergencyMessage() ? SmsCbMessage.MESSAGE_PRIORITY_EMERGENCY
: SmsCbMessage.MESSAGE_PRIORITY_NORMAL;
return new SmsCbMessage(SmsCbMessage.MESSAGE_FORMAT_3GPP,
header.getGeographicalScope(), header.getSerialNumber(), location,
header.getServiceCategory(), language, sb.toString(), priority,
header.getEtwsInfo(), header.getCmasInfo(), 0, null /* geometries */,
receivedTimeMillis, slotIndex, subId);
}
}
/**
* Parse WEA Handset Action Message(WHAM) a.k.a geo-fencing trigger message.
*
* WEA Handset Action Message(WHAM) is a cell broadcast service message broadcast by the network
* to direct devices to perform a geo-fencing check on selected alerts.
*
* WEA Handset Action Message(WHAM) requirements from ATIS-0700041 section 4
* 1. The Warning Message contents of a WHAM shall be in Cell Broadcast(CB) data format as
* defined in TS 23.041.
* 2. The Warning Message Contents of WHAM shall be limited to one CB page(max 20 referenced
* WEA messages).
* 3. The broadcast area for a WHAM shall be the union of the broadcast areas of the referenced
* WEA message.
* @param pdu cell broadcast pdu, including the header
* @return {@link GeoFencingTriggerMessage} instance
*/
public static GeoFencingTriggerMessage createGeoFencingTriggerMessage(byte[] pdu) {
try {
// Header length + 1(number of page). ATIS-0700041 define the number of page of
// geo-fencing trigger message is 1.
int whamOffset = SmsCbHeader.PDU_HEADER_LENGTH + 1;
BitStreamReader bitReader = new BitStreamReader(pdu, whamOffset);
int type = bitReader.read(4);
int length = bitReader.read(7);
// Skip the remained 5 bits
bitReader.skip();
int messageIdentifierCount = (length - 2) * 8 / 32;
List<CellBroadcastIdentity> cbIdentifiers = new ArrayList<>();
for (int i = 0; i < messageIdentifierCount; i++) {
// Both messageIdentifier and serialNumber are 16 bits integers.
// ATIS-0700041 Section 5.1.6
int messageIdentifier = bitReader.read(16);
int serialNumber = bitReader.read(16);
cbIdentifiers.add(new CellBroadcastIdentity(messageIdentifier, serialNumber));
}
return new GeoFencingTriggerMessage(type, cbIdentifiers);
} catch (Exception ex) {
Slog.e(TAG, "create geo-fencing trigger failed, ex = " + ex.toString());
return null;
}
}
/**
* Parse the broadcast area and maximum wait time from the Warning Area Coordinates TLV.
*
* @param pdu Warning Area Coordinates TLV.
* @param wacOffset the offset of Warning Area Coordinates TLV.
* @return a pair with the first element is maximum wait time and the second is the broadcast
* area. The default value of the maximum wait time is 255 which means use the device default
* value.
*/
private static Pair<Integer, List<Geometry>> parseWarningAreaCoordinates(
byte[] pdu, int wacOffset) {
// little-endian
int wacDataLength = (pdu[wacOffset + 1] << 8) | pdu[wacOffset];
int offset = wacOffset + 2;
if (offset + wacDataLength > pdu.length) {
throw new IllegalArgumentException("Invalid wac data, expected the length of pdu at"
+ "least " + offset + wacDataLength + ", actual is " + pdu.length);
}
BitStreamReader bitReader = new BitStreamReader(pdu, offset);
int maximumWaitTimeSec = SmsCbMessage.MAXIMUM_WAIT_TIME_NOT_SET;
List<Geometry> geo = new ArrayList<>();
int remainedBytes = wacDataLength;
while (remainedBytes > 0) {
int type = bitReader.read(4);
int length = bitReader.read(10);
remainedBytes -= length;
// Skip the 2 remained bits
bitReader.skip();
switch (type) {
case CbGeoUtils.GEO_FENCING_MAXIMUM_WAIT_TIME:
maximumWaitTimeSec = bitReader.read(8);
break;
case CbGeoUtils.GEOMETRY_TYPE_POLYGON:
List<LatLng> latLngs = new ArrayList<>();
// Each coordinate is represented by 44 bits integer.
// ATIS-0700041 5.2.4 Coordinate coding
int n = (length - 2) * 8 / 44;
for (int i = 0; i < n; i++) {
latLngs.add(getLatLng(bitReader));
}
// Skip the padding bits
bitReader.skip();
geo.add(new Polygon(latLngs));
break;
case CbGeoUtils.GEOMETRY_TYPE_CIRCLE:
LatLng center = getLatLng(bitReader);
// radius = (wacRadius / 2^6). The unit of wacRadius is km, we use meter as the
// distance unit during geo-fencing.
// ATIS-0700041 5.2.5 radius coding
double radius = (bitReader.read(20) * 1.0 / (1 << 6)) * 1000.0;
geo.add(new Circle(center, radius));
break;
default:
throw new IllegalArgumentException("Unsupported geoType = " + type);
}
}
return new Pair(maximumWaitTimeSec, geo);
}
/**
* The coordinate is (latitude, longitude), represented by a 44 bits integer.
* The coding is defined in ATIS-0700041 5.2.4
* @param bitReader
* @return coordinate (latitude, longitude)
*/
private static LatLng getLatLng(BitStreamReader bitReader) {
// wacLatitude = floor(((latitude + 90) / 180) * 2^22)
// wacLongitude = floor(((longitude + 180) / 360) * 2^22)
int wacLat = bitReader.read(22);
int wacLng = bitReader.read(22);
// latitude = wacLatitude * 180 / 2^22 - 90
// longitude = wacLongitude * 360 / 2^22 -180
return new LatLng((wacLat * 180.0 / (1 << 22)) - 90, (wacLng * 360.0 / (1 << 22) - 180));
}
/**
* Parse and unpack the UMTS body text according to the encoding in the data coding scheme.
*
* @param header the message header to use
* @param pdu the PDU to decode
* @return a pair of string containing the language and body of the message in order
*/
private static Pair<String, String> parseUmtsBody(SmsCbHeader header, byte[] pdu) {
// Payload may contain multiple pages
int nrPages = pdu[SmsCbHeader.PDU_HEADER_LENGTH];
String language = header.getDataCodingSchemeStructedData().language;
if (pdu.length < SmsCbHeader.PDU_HEADER_LENGTH + 1 + (PDU_BODY_PAGE_LENGTH + 1)
* nrPages) {
throw new IllegalArgumentException("Pdu length " + pdu.length + " does not match "
+ nrPages + " pages");
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < nrPages; i++) {
// Each page is 82 bytes followed by a length octet indicating
// the number of useful octets within those 82
int offset = SmsCbHeader.PDU_HEADER_LENGTH + 1 + (PDU_BODY_PAGE_LENGTH + 1) * i;
int length = pdu[offset + PDU_BODY_PAGE_LENGTH];
if (length > PDU_BODY_PAGE_LENGTH) {
throw new IllegalArgumentException("Page length " + length
+ " exceeds maximum value " + PDU_BODY_PAGE_LENGTH);
}
Pair<String, String> p = unpackBody(pdu, offset, length,
header.getDataCodingSchemeStructedData());
language = p.first;
sb.append(p.second);
}
return new Pair(language, sb.toString());
}
/**
* Parse and unpack the GSM body text according to the encoding in the data coding scheme.
* @param header the message header to use
* @param pdu the PDU to decode
* @return a pair of string containing the language and body of the message in order
*/
private static Pair<String, String> parseGsmBody(SmsCbHeader header, byte[] pdu) {
// Payload is one single page
int offset = SmsCbHeader.PDU_HEADER_LENGTH;
int length = pdu.length - offset;
return unpackBody(pdu, offset, length, header.getDataCodingSchemeStructedData());
}
/**
* Unpack body text from the pdu using the given encoding, position and length within the pdu.
*
* @param pdu The pdu
* @param offset Position of the first byte to unpack
* @param length Number of bytes to unpack
* @param dcs data coding scheme
* @return a Pair of Strings containing the language and body of the message
*/
private static Pair<String, String> unpackBody(byte[] pdu, int offset, int length,
DataCodingScheme dcs) {
String body = null;
String language = dcs.language;
switch (dcs.encoding) {
case SmsConstants.ENCODING_7BIT:
body = GsmAlphabet.gsm7BitPackedToString(pdu, offset, length * 8 / 7);
if (dcs.hasLanguageIndicator && body != null && body.length() > 2) {
// Language is two GSM characters followed by a CR.
// The actual body text is offset by 3 characters.
language = body.substring(0, 2);
body = body.substring(3);
}
break;
case SmsConstants.ENCODING_16BIT:
if (dcs.hasLanguageIndicator && pdu.length >= offset + 2) {
// Language is two GSM characters.
// The actual body text is offset by 2 bytes.
language = GsmAlphabet.gsm7BitPackedToString(pdu, offset, 2);
offset += 2;
length -= 2;
}
try {
body = new String(pdu, offset, (length & 0xfffe), "utf-16");
} catch (UnsupportedEncodingException e) {
// Apparently it wasn't valid UTF-16.
throw new IllegalArgumentException("Error decoding UTF-16 message", e);
}
break;
default:
break;
}
if (body != null) {
// Remove trailing carriage return
for (int i = body.length() - 1; i >= 0; i--) {
if (body.charAt(i) != CARRIAGE_RETURN) {
body = body.substring(0, i + 1);
break;
}
}
} else {
body = "";
}
return new Pair<String, String>(language, body);
}
/** A class use to facilitate the processing of bits stream data. */
private static final class BitStreamReader {
/** The bits stream represent by a bytes array. */
private final byte[] mData;
/** The offset of the current byte. */
private int mCurrentOffset;
/**
* The remained bits of the current byte which have not been read. The most significant
* will be read first, so the remained bits are always the least significant bits.
*/
private int mRemainedBit;
/**
* Constructor
* @param data bit stream data represent by byte array.
* @param offset the offset of the first byte.
*/
BitStreamReader(byte[] data, int offset) {
mData = data;
mCurrentOffset = offset;
mRemainedBit = 8;
}
/**
* Read the first {@code count} bits.
* @param count the number of bits need to read
* @return {@code bits} represent by an 32-bits integer, therefore {@code count} must be no
* greater than 32.
*/
public int read(int count) throws IndexOutOfBoundsException {
int val = 0;
while (count > 0) {
if (count >= mRemainedBit) {
val <<= mRemainedBit;
val |= mData[mCurrentOffset] & ((1 << mRemainedBit) - 1);
count -= mRemainedBit;
mRemainedBit = 8;
++mCurrentOffset;
} else {
val <<= count;
val |= (mData[mCurrentOffset] & ((1 << mRemainedBit) - 1))
>> (mRemainedBit - count);
mRemainedBit -= count;
count = 0;
}
}
return val;
}
/**
* Skip the current bytes if the remained bits is less than 8. This is useful when
* processing the padding or reserved bits.
*/
public void skip() {
if (mRemainedBit < 8) {
mRemainedBit = 8;
++mCurrentOffset;
}
}
}
/**
* Part of a GSM SMS cell broadcast message which may trigger geo-fencing logic.
* @hide
*/
public static final class GeoFencingTriggerMessage {
/**
* Indicate the list of active alerts share their warning area coordinates which means the
* broadcast area is the union of the broadcast areas of the active alerts in this list.
*/
public static final int TYPE_ACTIVE_ALERT_SHARE_WAC = 2;
public final int type;
public final List<CellBroadcastIdentity> cbIdentifiers;
GeoFencingTriggerMessage(int type, @NonNull List<CellBroadcastIdentity> cbIdentifiers) {
this.type = type;
this.cbIdentifiers = cbIdentifiers;
}
/**
* Whether the trigger message indicates that the broadcast areas are shared between all
* active alerts.
* @return true if broadcast areas are to be shared
*/
boolean shouldShareBroadcastArea() {
return type == TYPE_ACTIVE_ALERT_SHARE_WAC;
}
static final class CellBroadcastIdentity {
public final int messageIdentifier;
public final int serialNumber;
CellBroadcastIdentity(int messageIdentifier, int serialNumber) {
this.messageIdentifier = messageIdentifier;
this.serialNumber = serialNumber;
}
}
@Override
public String toString() {
String identifiers = cbIdentifiers.stream()
.map(cbIdentifier ->String.format("(msgId = %d, serial = %d)",
cbIdentifier.messageIdentifier, cbIdentifier.serialNumber))
.collect(Collectors.joining(","));
return "triggerType=" + type + " identifiers=" + identifiers;
}
}
}