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[NAN] Add LV utilities (TLV with T size of 0).

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NAN uses LV (not TLV). Expose an LV variant of TLV to make API
cleaner.

Bug: 30096512
Change-Id: I74b4c514d50f1df5750b521bd68a5e2d832d92c3
This commit is contained in:
Etan Cohen
2016-07-18 13:43:17 -07:00
parent e40b4d344e
commit 009b1fcb85
3 changed files with 352 additions and 12 deletions
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340
wifi/java/android/net/wifi/nan/LvBufferUtils.java Normal file
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@@ -0,0 +1,340 @@
/*
* Copyright (C) 2016 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 android.net.wifi.nan;
import android.annotation.Nullable;
import libcore.io.Memory;
import java.nio.ByteOrder;
import java.util.Iterator;
/**
* Utility class to construct and parse byte arrays using the LV format -
* Length/Value format. The utilities accept a configuration of the size of
* the Length field.
*
* @hide PROPOSED_NAN_API
*/
public class LvBufferUtils {
private LvBufferUtils() {
// no reason to ever create this class
}
/**
* Utility class to construct byte arrays using the LV format - Length/Value.
* <p>
* A constructor is created specifying the size of the Length (L) field.
* <p>
* The byte array is either provided (using
* {@link LvBufferUtils.LvConstructor#wrap(byte[])}) or allocated (using
* {@link LvBufferUtils.LvConstructor#allocate(int)}).
* <p>
* Values are added to the structure using the {@code LvConstructor.put*()}
* methods.
* <p>
* The final byte array is obtained using {@link LvBufferUtils.LvConstructor#getArray()}.
*/
public static class LvConstructor {
private TlvBufferUtils.TlvConstructor mTlvImpl;
/**
* Define a LV constructor with the specified size of the Length (L) field.
*
* @param lengthSize Number of bytes used for the Length (L) field.
* Values of 1 or 2 bytes are allowed.
*/
public LvConstructor(int lengthSize) {
mTlvImpl = new TlvBufferUtils.TlvConstructor(0, lengthSize);
}
/**
* Set the byte array to be used to construct the LV.
*
* @param array Byte array to be formatted.
* @return The constructor to facilitate chaining
* {@code ctr.putXXX(..).putXXX(..)}.
*/
public LvBufferUtils.LvConstructor wrap(@Nullable byte[] array) {
mTlvImpl.wrap(array);
return this;
}
/**
* Allocates a new byte array to be used ot construct a LV.
*
* @param capacity The size of the byte array to be allocated.
* @return The constructor to facilitate chaining
* {@code ctr.putXXX(..).putXXX(..)}.
*/
public LvBufferUtils.LvConstructor allocate(int capacity) {
mTlvImpl.allocate(capacity);
return this;
}
/**
* Copies a byte into the LV array.
*
* @param b The byte to be inserted into the structure.
* @return The constructor to facilitate chaining
* {@code ctr.putXXX(..).putXXX(..)}.
*/
public LvBufferUtils.LvConstructor putByte(byte b) {
mTlvImpl.putByte(0, b);
return this;
}
/**
* Copies a byte array into the LV.
*
* @param array The array to be copied into the LV structure.
* @param offset Start copying from the array at the specified offset.
* @param length Copy the specified number (length) of bytes from the
* array.
* @return The constructor to facilitate chaining
* {@code ctr.putXXX(..).putXXX(..)}.
*/
public LvBufferUtils.LvConstructor putByteArray(@Nullable byte[] array, int offset,
int length) {
mTlvImpl.putByteArray(0, array, offset, length);
return this;
}
/**
* Copies a byte array into the LV.
*
* @param array The array to be copied (in full) into the LV structure.
* @return The constructor to facilitate chaining
* {@code ctr.putXXX(..).putXXX(..)}.
*/
public LvBufferUtils.LvConstructor putByteArray(int type, @Nullable byte[] array) {
return putByteArray(array, 0, (array == null) ? 0 : array.length);
}
/**
* Places a zero length element (i.e. Length field = 0) into the LV.
*
* @return The constructor to facilitate chaining
* {@code ctr.putXXX(..).putXXX(..)}.
*/
public LvBufferUtils.LvConstructor putZeroLengthElement() {
mTlvImpl.putZeroLengthElement(0);
return this;
}
/**
* Copies short into the LV.
*
* @param data The short to be inserted into the structure.
* @return The constructor to facilitate chaining
* {@code ctr.putXXX(..).putXXX(..)}.
*/
public LvBufferUtils.LvConstructor putShort(short data) {
mTlvImpl.putShort(0, data);
return this;
}
/**
* Copies integer into the LV.
*
* @param data The integer to be inserted into the structure.
* @return The constructor to facilitate chaining
* {@code ctr.putXXX(..).putXXX(..)}.
*/
public LvBufferUtils.LvConstructor putInt(int data) {
mTlvImpl.putInt(0, data);
return this;
}
/**
* Copies a String's byte representation into the LV.
*
* @param data The string whose bytes are to be inserted into the
* structure.
* @return The constructor to facilitate chaining
* {@code ctr.putXXX(..).putXXX(..)}.
*/
public LvBufferUtils.LvConstructor putString(@Nullable String data) {
mTlvImpl.putString(0, data);
return this;
}
/**
* Returns the constructed LV formatted byte-array. This array is a copy of the wrapped
* or allocated array - truncated to just the significant bytes - i.e. those written into
* the LV.
*
* @return The byte array containing the LV formatted structure.
*/
public byte[] getArray() {
return mTlvImpl.getArray();
}
}
/**
* Utility class used when iterating over an LV formatted byte-array. Use
* {@link LvBufferUtils.LvIterable} to iterate over array. A {@link LvBufferUtils.LvElement}
* represents each entry in a LV formatted byte-array.
*/
public static class LvElement {
/**
* The Length (L) field of the current LV element.
*/
public int length;
/**
* The Value (V) field - a raw byte array representing the current LV
* element where the entry starts at {@link LvBufferUtils.LvElement#offset}.
*/
public byte[] refArray;
/**
* The offset to be used into {@link LvBufferUtils.LvElement#refArray} to access the
* raw data representing the current LV element.
*/
public int offset;
private LvElement(int length, @Nullable byte[] refArray, int offset) {
this.length = length;
this.refArray = refArray;
this.offset = offset;
}
/**
* Utility function to return a byte representation of a LV element of
* length 1. Note: an attempt to call this function on a LV item whose
* {@link LvBufferUtils.LvElement#length} is != 1 will result in an exception.
*
* @return byte representation of current LV element.
*/
public byte getByte() {
if (length != 1) {
throw new IllegalArgumentException(
"Accesing a byte from a LV element of length " + length);
}
return refArray[offset];
}
/**
* Utility function to return a short representation of a LV element of
* length 2. Note: an attempt to call this function on a LV item whose
* {@link LvBufferUtils.LvElement#length} is != 2 will result in an exception.
*
* @return short representation of current LV element.
*/
public short getShort() {
if (length != 2) {
throw new IllegalArgumentException(
"Accesing a short from a LV element of length " + length);
}
return Memory.peekShort(refArray, offset, ByteOrder.BIG_ENDIAN);
}
/**
* Utility function to return an integer representation of a LV element
* of length 4. Note: an attempt to call this function on a LV item
* whose {@link LvBufferUtils.LvElement#length} is != 4 will result in an exception.
*
* @return integer representation of current LV element.
*/
public int getInt() {
if (length != 4) {
throw new IllegalArgumentException(
"Accesing an int from a LV element of length " + length);
}
return Memory.peekInt(refArray, offset, ByteOrder.BIG_ENDIAN);
}
/**
* Utility function to return a String representation of a LV element.
*
* @return String representation of the current LV element.
*/
public String getString() {
return new String(refArray, offset, length);
}
}
/**
* Utility class to iterate over a LV formatted byte-array.
*/
public static class LvIterable implements Iterable<LvBufferUtils.LvElement> {
private final TlvBufferUtils.TlvIterable mTlvIterable;
/**
* Constructs an LvIterable object - specifying the format of the LV
* (the size of the Length field), and the byte array whose data is to be parsed.
*
* @param lengthSize Number of bytes sued for the Length (L) field.
* Values values are 1 or 2 bytes.
* @param array The LV formatted byte-array to parse.
*/
public LvIterable(int lengthSize, @Nullable byte[] array) {
mTlvIterable = new TlvBufferUtils.TlvIterable(0, lengthSize, array);
}
/**
* Prints out a parsed representation of the LV-formatted byte array.
* Whenever possible bytes, shorts, and integer are printed out (for
* fields whose length is 1, 2, or 4 respectively).
*/
@Override
public String toString() {
return mTlvIterable.toString();
}
/**
* Returns an iterator to step through a LV formatted byte-array. The
* individual elements returned by the iterator are {@link LvBufferUtils.LvElement}.
*/
@Override
public Iterator<LvBufferUtils.LvElement> iterator() {
return new Iterator<LvBufferUtils.LvElement>() {
private Iterator<TlvBufferUtils.TlvElement> mTlvIterator = mTlvIterable.iterator();
@Override
public boolean hasNext() {
return mTlvIterator.hasNext();
}
@Override
public LvBufferUtils.LvElement next() {
TlvBufferUtils.TlvElement tlvE = mTlvIterator.next();
return new LvElement(tlvE.length, tlvE.refArray, tlvE.offset);
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
}
}
/**
* Validates that a LV array is constructed correctly. I.e. that its specified Length
* fields correctly fill the specified length (and do not overshoot).
*
* @param array The LV array to verify.
* @param lengthSize The size (in bytes) of the length field. Valid values are 1 or 2.
* @return A boolean indicating whether the array is valid (true) or invalid (false).
*/
public static boolean isValid(@Nullable byte[] array, int lengthSize) {
return TlvBufferUtils.isValid(array, 0, lengthSize);
}
}

12
wifi/java/android/net/wifi/nan/PublishConfig.java
View File

@@ -116,8 +116,8 @@ public class PublishConfig implements Parcelable {
public String toString() {
return "PublishConfig [mServiceName='" + mServiceName + ", mServiceSpecificInfo='" + (
(mServiceSpecificInfo == null) ? "null" : HexEncoding.encode(mServiceSpecificInfo))
+ ", mTxFilter=" + (new TlvBufferUtils.TlvIterable(0, 1, mTxFilter)).toString()
+ ", mRxFilter=" + (new TlvBufferUtils.TlvIterable(0, 1, mRxFilter)).toString()
+ ", mTxFilter=" + (new LvBufferUtils.LvIterable(1, mTxFilter)).toString()
+ ", mRxFilter=" + (new LvBufferUtils.LvIterable(1, mRxFilter)).toString()
+ ", mPublishType=" + mPublishType + ", mPublishCount=" + mPublishCount
+ ", mTtlSec=" + mTtlSec + ", mEnableTerminateNotification="
+ mEnableTerminateNotification + "]";
@@ -206,11 +206,11 @@ public class PublishConfig implements Parcelable {
public void validate() throws IllegalArgumentException {
WifiNanUtils.validateServiceName(mServiceName);
if (!TlvBufferUtils.isValid(mTxFilter, 0, 1)) {
if (!LvBufferUtils.isValid(mTxFilter, 1)) {
throw new IllegalArgumentException(
"Invalid txFilter configuration - LV fields do not match up to length");
}
if (!TlvBufferUtils.isValid(mRxFilter, 0, 1)) {
if (!LvBufferUtils.isValid(mRxFilter, 1)) {
throw new IllegalArgumentException(
"Invalid rxFilter configuration - LV fields do not match up to length");
}
@@ -310,7 +310,7 @@ public class PublishConfig implements Parcelable {
* determine whether they match - in addition to just relying on the
* service name.
* <p>
* Format is an LV byte array - the {@link TlvBufferUtils} utility class
* Format is an LV byte array - the {@link LvBufferUtils} utility class
* is available to form and parse.
*
* @param txFilter The byte-array containing the LV formatted transmit
@@ -331,7 +331,7 @@ public class PublishConfig implements Parcelable {
* (active subscribers) - in addition to just relying on the service
* name.
* <p>
* Format is an LV byte array - the {@link TlvBufferUtils} utility class
* Format is an LV byte array - the {@link LvBufferUtils} utility class
* is available to form and parse.
*
* @param rxFilter The byte-array containing the LV formatted receive

12
wifi/java/android/net/wifi/nan/SubscribeConfig.java
View File

@@ -140,8 +140,8 @@ public class SubscribeConfig implements Parcelable {
public String toString() {
return "SubscribeConfig [mServiceName='" + mServiceName + ", mServiceSpecificInfo='" + (
(mServiceSpecificInfo == null) ? "null" : HexEncoding.encode(mServiceSpecificInfo))
+ ", mTxFilter=" + (new TlvBufferUtils.TlvIterable(0, 1, mTxFilter)).toString()
+ ", mRxFilter=" + (new TlvBufferUtils.TlvIterable(0, 1, mRxFilter)).toString()
+ ", mTxFilter=" + (new LvBufferUtils.LvIterable(1, mTxFilter)).toString()
+ ", mRxFilter=" + (new LvBufferUtils.LvIterable(1, mRxFilter)).toString()
+ ", mSubscribeType=" + mSubscribeType + ", mSubscribeCount=" + mSubscribeCount
+ ", mTtlSec=" + mTtlSec + ", mMatchType=" + mMatchStyle
+ ", mEnableTerminateNotification=" + mEnableTerminateNotification + "]";
@@ -234,11 +234,11 @@ public class SubscribeConfig implements Parcelable {
public void validate() throws IllegalArgumentException {
WifiNanUtils.validateServiceName(mServiceName);
if (!TlvBufferUtils.isValid(mTxFilter, 0, 1)) {
if (!LvBufferUtils.isValid(mTxFilter, 1)) {
throw new IllegalArgumentException(
"Invalid txFilter configuration - LV fields do not match up to length");
}
if (!TlvBufferUtils.isValid(mRxFilter, 0, 1)) {
if (!LvBufferUtils.isValid(mRxFilter, 1)) {
throw new IllegalArgumentException(
"Invalid rxFilter configuration - LV fields do not match up to length");
}
@@ -344,7 +344,7 @@ public class SubscribeConfig implements Parcelable {
* publishers) to determine whether they match - in addition to just
* relying on the service name.
* <p>
* Format is an LV byte array - the {@link TlvBufferUtils} utility class
* Format is an LV byte array - the {@link LvBufferUtils} utility class
* is available to form and parse.
*
* @param txFilter The byte-array containing the LV formatted transmit
@@ -364,7 +364,7 @@ public class SubscribeConfig implements Parcelable {
* subscriber to determine whether they match transmitted publish
* packets - in addition to just relying on the service name.
* <p>
* Format is an LV byte array - the {@link TlvBufferUtils} utility class
* Format is an LV byte array - the {@link LvBufferUtils} utility class
* is available to form and parse.
*
* @param rxFilter The byte-array containing the LV formatted receive