io.netty.handler.codec.spdy.SpdyHeaderBlockRawDecoder Maven / Gradle / Ivy
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/*
* Copyright 2014 The Netty Project
*
* The Netty Project licenses this file to you 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 io.netty.handler.codec.spdy;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.util.internal.ObjectUtil;
import static io.netty.handler.codec.spdy.SpdyCodecUtil.getSignedInt;
public class SpdyHeaderBlockRawDecoder extends SpdyHeaderBlockDecoder {
private static final int LENGTH_FIELD_SIZE = 4;
private final int maxHeaderSize;
private State state;
private ByteBuf cumulation;
private int headerSize;
private int numHeaders;
private int length;
private String name;
private enum State {
READ_NUM_HEADERS,
READ_NAME_LENGTH,
READ_NAME,
SKIP_NAME,
READ_VALUE_LENGTH,
READ_VALUE,
SKIP_VALUE,
END_HEADER_BLOCK,
ERROR
}
public SpdyHeaderBlockRawDecoder(SpdyVersion spdyVersion, int maxHeaderSize) {
ObjectUtil.checkNotNull(spdyVersion, "spdyVersion");
this.maxHeaderSize = maxHeaderSize;
state = State.READ_NUM_HEADERS;
}
private static int readLengthField(ByteBuf buffer) {
int length = getSignedInt(buffer, buffer.readerIndex());
buffer.skipBytes(LENGTH_FIELD_SIZE);
return length;
}
@Override
void decode(ByteBufAllocator alloc, ByteBuf headerBlock, SpdyHeadersFrame frame) throws Exception {
ObjectUtil.checkNotNull(headerBlock, "headerBlock");
ObjectUtil.checkNotNull(frame, "frame");
if (cumulation == null) {
decodeHeaderBlock(headerBlock, frame);
if (headerBlock.isReadable()) {
cumulation = alloc.buffer(headerBlock.readableBytes());
cumulation.writeBytes(headerBlock);
}
} else {
cumulation.writeBytes(headerBlock);
decodeHeaderBlock(cumulation, frame);
if (cumulation.isReadable()) {
cumulation.discardReadBytes();
} else {
releaseBuffer();
}
}
}
protected void decodeHeaderBlock(ByteBuf headerBlock, SpdyHeadersFrame frame) throws Exception {
int skipLength;
while (headerBlock.isReadable()) {
switch(state) {
case READ_NUM_HEADERS:
if (headerBlock.readableBytes() < LENGTH_FIELD_SIZE) {
return;
}
numHeaders = readLengthField(headerBlock);
if (numHeaders < 0) {
state = State.ERROR;
frame.setInvalid();
} else if (numHeaders == 0) {
state = State.END_HEADER_BLOCK;
} else {
state = State.READ_NAME_LENGTH;
}
break;
case READ_NAME_LENGTH:
if (headerBlock.readableBytes() < LENGTH_FIELD_SIZE) {
return;
}
length = readLengthField(headerBlock);
// Recipients of a zero-length name must issue a stream error
if (length <= 0) {
state = State.ERROR;
frame.setInvalid();
} else if (length > maxHeaderSize || headerSize > maxHeaderSize - length) {
headerSize = maxHeaderSize + 1;
state = State.SKIP_NAME;
frame.setTruncated();
} else {
headerSize += length;
state = State.READ_NAME;
}
break;
case READ_NAME:
if (headerBlock.readableBytes() < length) {
return;
}
byte[] nameBytes = new byte[length];
headerBlock.readBytes(nameBytes);
name = new String(nameBytes, "UTF-8");
// Check for identically named headers
if (frame.headers().contains(name)) {
state = State.ERROR;
frame.setInvalid();
} else {
state = State.READ_VALUE_LENGTH;
}
break;
case SKIP_NAME:
skipLength = Math.min(headerBlock.readableBytes(), length);
headerBlock.skipBytes(skipLength);
length -= skipLength;
if (length == 0) {
state = State.READ_VALUE_LENGTH;
}
break;
case READ_VALUE_LENGTH:
if (headerBlock.readableBytes() < LENGTH_FIELD_SIZE) {
return;
}
length = readLengthField(headerBlock);
// Recipients of illegal value fields must issue a stream error
if (length < 0) {
state = State.ERROR;
frame.setInvalid();
} else if (length == 0) {
if (!frame.isTruncated()) {
// SPDY/3 allows zero-length (empty) header values
frame.headers().add(name, "");
}
name = null;
if (--numHeaders == 0) {
state = State.END_HEADER_BLOCK;
} else {
state = State.READ_NAME_LENGTH;
}
} else if (length > maxHeaderSize || headerSize > maxHeaderSize - length) {
headerSize = maxHeaderSize + 1;
name = null;
state = State.SKIP_VALUE;
frame.setTruncated();
} else {
headerSize += length;
state = State.READ_VALUE;
}
break;
case READ_VALUE:
if (headerBlock.readableBytes() < length) {
return;
}
byte[] valueBytes = new byte[length];
headerBlock.readBytes(valueBytes);
// Add Name/Value pair to headers
int index = 0;
int offset = 0;
// Value must not start with a NULL character
if (valueBytes[0] == (byte) 0) {
state = State.ERROR;
frame.setInvalid();
break;
}
while (index < length) {
while (index < valueBytes.length && valueBytes[index] != (byte) 0) {
index ++;
}
if (index < valueBytes.length) {
// Received NULL character
if (index + 1 == valueBytes.length || valueBytes[index + 1] == (byte) 0) {
// Value field ended with a NULL character or
// received multiple, in-sequence NULL characters.
// Recipients of illegal value fields must issue a stream error
state = State.ERROR;
frame.setInvalid();
break;
}
}
String value = new String(valueBytes, offset, index - offset, "UTF-8");
try {
frame.headers().add(name, value);
} catch (IllegalArgumentException e) {
// Name contains NULL or non-ascii characters
state = State.ERROR;
frame.setInvalid();
break;
}
index ++;
offset = index;
}
name = null;
// If we broke out of the add header loop, break here
if (state == State.ERROR) {
break;
}
if (--numHeaders == 0) {
state = State.END_HEADER_BLOCK;
} else {
state = State.READ_NAME_LENGTH;
}
break;
case SKIP_VALUE:
skipLength = Math.min(headerBlock.readableBytes(), length);
headerBlock.skipBytes(skipLength);
length -= skipLength;
if (length == 0) {
if (--numHeaders == 0) {
state = State.END_HEADER_BLOCK;
} else {
state = State.READ_NAME_LENGTH;
}
}
break;
case END_HEADER_BLOCK:
state = State.ERROR;
frame.setInvalid();
break;
case ERROR:
headerBlock.skipBytes(headerBlock.readableBytes());
return;
default:
throw new Error("Shouldn't reach here.");
}
}
}
@Override
void endHeaderBlock(SpdyHeadersFrame frame) throws Exception {
if (state != State.END_HEADER_BLOCK) {
frame.setInvalid();
}
releaseBuffer();
// Initialize header block decoding fields
headerSize = 0;
name = null;
state = State.READ_NUM_HEADERS;
}
@Override
void end() {
releaseBuffer();
}
private void releaseBuffer() {
if (cumulation != null) {
cumulation.release();
cumulation = null;
}
}
}