/*
* Copyright (C) 2011 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.cat;
import android.telephony.Rlog;
import java.util.ArrayList;
import java.util.List;
/**
* Class for representing COMPREHENSION-TLV objects.
*
* @see "ETSI TS 101 220 subsection 7.1.1"
*
* {@hide}
*/
class ComprehensionTlv {
private static final String LOG_TAG = "ComprehensionTlv";
private int mTag;
private boolean mCr;
private int mLength;
private int mValueIndex;
private byte[] mRawValue;
/**
* Constructor. Private on purpose. Use
* {@link #decodeMany(byte[], int) decodeMany} or
* {@link #decode(byte[], int) decode} method.
*
* @param tag The tag for this object
* @param cr Comprehension Required flag
* @param length Length of the value
* @param data Byte array containing the value
* @param valueIndex Index in data at which the value starts
*/
protected ComprehensionTlv(int tag, boolean cr, int length, byte[] data,
int valueIndex) {
mTag = tag;
mCr = cr;
mLength = length;
mValueIndex = valueIndex;
mRawValue = data;
}
public int getTag() {
return mTag;
}
public boolean isComprehensionRequired() {
return mCr;
}
public int getLength() {
return mLength;
}
public int getValueIndex() {
return mValueIndex;
}
public byte[] getRawValue() {
return mRawValue;
}
/**
* Parses a list of COMPREHENSION-TLV objects from a byte array.
*
* @param data A byte array containing data to be parsed
* @param startIndex Index in data at which to start parsing
* @return A list of COMPREHENSION-TLV objects parsed
* @throws ResultException
*/
public static List<ComprehensionTlv> decodeMany(byte[] data, int startIndex)
throws ResultException {
ArrayList<ComprehensionTlv> items = new ArrayList<ComprehensionTlv>();
int endIndex = data.length;
while (startIndex < endIndex) {
ComprehensionTlv ctlv = ComprehensionTlv.decode(data, startIndex);
if (ctlv != null) {
items.add(ctlv);
startIndex = ctlv.mValueIndex + ctlv.mLength;
} else {
CatLog.d(LOG_TAG, "decodeMany: ctlv is null, stop decoding");
break;
}
}
return items;
}
/**
* Parses an COMPREHENSION-TLV object from a byte array.
*
* @param data A byte array containing data to be parsed
* @param startIndex Index in data at which to start parsing
* @return A COMPREHENSION-TLV object parsed
* @throws ResultException
*/
public static ComprehensionTlv decode(byte[] data, int startIndex)
throws ResultException {
int curIndex = startIndex;
int endIndex = data.length;
try {
/* tag */
int tag;
boolean cr; // Comprehension required flag
int temp = data[curIndex++] & 0xff;
switch (temp) {
case 0:
case 0xff:
case 0x80:
Rlog.d("CAT ", "decode: unexpected first tag byte=" + Integer.toHexString(temp) +
", startIndex=" + startIndex + " curIndex=" + curIndex +
" endIndex=" + endIndex);
// Return null which will stop decoding, this has occurred
// with Ghana MTN simcard and JDI simcard.
return null;
case 0x7f: // tag is in three-byte format
tag = ((data[curIndex] & 0xff) << 8)
| (data[curIndex + 1] & 0xff);
cr = (tag & 0x8000) != 0;
tag &= ~0x8000;
curIndex += 2;
break;
default: // tag is in single-byte format
tag = temp;
cr = (tag & 0x80) != 0;
tag &= ~0x80;
break;
}
/* length */
int length;
temp = data[curIndex++] & 0xff;
if (temp < 0x80) {
length = temp;
} else if (temp == 0x81) {
length = data[curIndex++] & 0xff;
if (length < 0x80) {
throw new ResultException(
ResultCode.CMD_DATA_NOT_UNDERSTOOD,
"length < 0x80 length=" + Integer.toHexString(length) +
" startIndex=" + startIndex + " curIndex=" + curIndex +
" endIndex=" + endIndex);
}
} else if (temp == 0x82) {
length = ((data[curIndex] & 0xff) << 8)
| (data[curIndex + 1] & 0xff);
curIndex += 2;
if (length < 0x100) {
throw new ResultException(
ResultCode.CMD_DATA_NOT_UNDERSTOOD,
"two byte length < 0x100 length=" + Integer.toHexString(length) +
" startIndex=" + startIndex + " curIndex=" + curIndex +
" endIndex=" + endIndex);
}
} else if (temp == 0x83) {
length = ((data[curIndex] & 0xff) << 16)
| ((data[curIndex + 1] & 0xff) << 8)
| (data[curIndex + 2] & 0xff);
curIndex += 3;
if (length < 0x10000) {
throw new ResultException(
ResultCode.CMD_DATA_NOT_UNDERSTOOD,
"three byte length < 0x10000 length=0x" + Integer.toHexString(length) +
" startIndex=" + startIndex + " curIndex=" + curIndex +
" endIndex=" + endIndex);
}
} else {
throw new ResultException(ResultCode.CMD_DATA_NOT_UNDERSTOOD,
"Bad length modifer=" + temp +
" startIndex=" + startIndex + " curIndex=" + curIndex +
" endIndex=" + endIndex);
}
return new ComprehensionTlv(tag, cr, length, data, curIndex);
} catch (IndexOutOfBoundsException e) {
throw new ResultException(ResultCode.CMD_DATA_NOT_UNDERSTOOD,
"IndexOutOfBoundsException" + " startIndex=" + startIndex +
" curIndex=" + curIndex + " endIndex=" + endIndex);
}
}
}
|
