netty5/codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.java
Bennett Lynch bcb62be62b
Consolidate HttpObjectDecoder default values into constants (#10344)
Motivation

HttpObjectDecoder and its associated classes make frequent use of
default values for maxInitialLineLength, maxHeaderSize, maxChunkSize,
etc. Today, these defaults are defined in-line in constructors and
duplicated across many classes. This repetition is more prone to error
and inconsistencies.

Furthermore, due to the current lack of builder support, if a user wants
to change just one of these values (e.g., maxHeaderSize), they are also
required to know and repeat the other default values (e.g.,
maxInitialLineLength and maxChunkSize).

The primary motivation for this change is as we are considering adding
another constructor parameter (for multiple content length behavior),
appending this parameter may require some users to have prior knowledge
of the default initialBufferSize, and it would be cleaner to allow them
to reference the default constant.

Modifications

* Consolidate the HttpObjectDecoder default values into public constants
* Reference these constants where possible

Result

No functional change. Additional telescoping constructors will be easier
and safer to write. Users may have an easier experience changing single
parameters.
2020-06-12 07:39:10 +02:00

959 lines
36 KiB
Java

/*
* Copyright 2012 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.http;
import static io.netty.util.internal.ObjectUtil.checkPositive;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.ByteToMessageDecoder;
import io.netty.handler.codec.DecoderResult;
import io.netty.handler.codec.PrematureChannelClosureException;
import io.netty.handler.codec.TooLongFrameException;
import io.netty.util.ByteProcessor;
import io.netty.util.internal.AppendableCharSequence;
import java.util.List;
/**
* Decodes {@link ByteBuf}s into {@link HttpMessage}s and
* {@link HttpContent}s.
*
* <h3>Parameters that prevents excessive memory consumption</h3>
* <table border="1">
* <tr>
* <th>Name</th><th>Meaning</th>
* </tr>
* <tr>
* <td>{@code maxInitialLineLength}</td>
* <td>The maximum length of the initial line
* (e.g. {@code "GET / HTTP/1.0"} or {@code "HTTP/1.0 200 OK"})
* If the length of the initial line exceeds this value, a
* {@link TooLongFrameException} will be raised.</td>
* </tr>
* <tr>
* <td>{@code maxHeaderSize}</td>
* <td>The maximum length of all headers. If the sum of the length of each
* header exceeds this value, a {@link TooLongFrameException} will be raised.</td>
* </tr>
* <tr>
* <td>{@code maxChunkSize}</td>
* <td>The maximum length of the content or each chunk. If the content length
* (or the length of each chunk) exceeds this value, the content or chunk
* will be split into multiple {@link HttpContent}s whose length is
* {@code maxChunkSize} at maximum.</td>
* </tr>
* </table>
*
* <h3>Chunked Content</h3>
*
* If the content of an HTTP message is greater than {@code maxChunkSize} or
* the transfer encoding of the HTTP message is 'chunked', this decoder
* generates one {@link HttpMessage} instance and its following
* {@link HttpContent}s per single HTTP message to avoid excessive memory
* consumption. For example, the following HTTP message:
* <pre>
* GET / HTTP/1.1
* Transfer-Encoding: chunked
*
* 1a
* abcdefghijklmnopqrstuvwxyz
* 10
* 1234567890abcdef
* 0
* Content-MD5: ...
* <i>[blank line]</i>
* </pre>
* triggers {@link HttpRequestDecoder} to generate 3 objects:
* <ol>
* <li>An {@link HttpRequest},</li>
* <li>The first {@link HttpContent} whose content is {@code 'abcdefghijklmnopqrstuvwxyz'},</li>
* <li>The second {@link LastHttpContent} whose content is {@code '1234567890abcdef'}, which marks
* the end of the content.</li>
* </ol>
*
* If you prefer not to handle {@link HttpContent}s by yourself for your
* convenience, insert {@link HttpObjectAggregator} after this decoder in the
* {@link ChannelPipeline}. However, please note that your server might not
* be as memory efficient as without the aggregator.
*
* <h3>Extensibility</h3>
*
* Please note that this decoder is designed to be extended to implement
* a protocol derived from HTTP, such as
* <a href="http://en.wikipedia.org/wiki/Real_Time_Streaming_Protocol">RTSP</a> and
* <a href="http://en.wikipedia.org/wiki/Internet_Content_Adaptation_Protocol">ICAP</a>.
* To implement the decoder of such a derived protocol, extend this class and
* implement all abstract methods properly.
*/
public abstract class HttpObjectDecoder extends ByteToMessageDecoder {
public static final int DEFAULT_MAX_INITIAL_LINE_LENGTH = 4096;
public static final int DEFAULT_MAX_HEADER_SIZE = 8192;
public static final boolean DEFAULT_CHUNKED_SUPPORTED = true;
public static final int DEFAULT_MAX_CHUNK_SIZE = 8192;
public static final boolean DEFAULT_VALIDATE_HEADERS = true;
public static final int DEFAULT_INITIAL_BUFFER_SIZE = 128;
private static final String EMPTY_VALUE = "";
private final int maxChunkSize;
private final boolean chunkedSupported;
protected final boolean validateHeaders;
private final HeaderParser headerParser;
private final LineParser lineParser;
private HttpMessage message;
private long chunkSize;
private long contentLength = Long.MIN_VALUE;
private volatile boolean resetRequested;
// These will be updated by splitHeader(...)
private CharSequence name;
private CharSequence value;
private LastHttpContent trailer;
/**
* The internal state of {@link HttpObjectDecoder}.
* <em>Internal use only</em>.
*/
private enum State {
SKIP_CONTROL_CHARS,
READ_INITIAL,
READ_HEADER,
READ_VARIABLE_LENGTH_CONTENT,
READ_FIXED_LENGTH_CONTENT,
READ_CHUNK_SIZE,
READ_CHUNKED_CONTENT,
READ_CHUNK_DELIMITER,
READ_CHUNK_FOOTER,
BAD_MESSAGE,
UPGRADED
}
private State currentState = State.SKIP_CONTROL_CHARS;
/**
* Creates a new instance with the default
* {@code maxInitialLineLength (4096}}, {@code maxHeaderSize (8192)}, and
* {@code maxChunkSize (8192)}.
*/
protected HttpObjectDecoder() {
this(DEFAULT_MAX_INITIAL_LINE_LENGTH, DEFAULT_MAX_HEADER_SIZE, DEFAULT_MAX_CHUNK_SIZE,
DEFAULT_CHUNKED_SUPPORTED);
}
/**
* Creates a new instance with the specified parameters.
*/
protected HttpObjectDecoder(
int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean chunkedSupported) {
this(maxInitialLineLength, maxHeaderSize, maxChunkSize, chunkedSupported, DEFAULT_VALIDATE_HEADERS);
}
/**
* Creates a new instance with the specified parameters.
*/
protected HttpObjectDecoder(
int maxInitialLineLength, int maxHeaderSize, int maxChunkSize,
boolean chunkedSupported, boolean validateHeaders) {
this(maxInitialLineLength, maxHeaderSize, maxChunkSize, chunkedSupported, validateHeaders,
DEFAULT_INITIAL_BUFFER_SIZE);
}
protected HttpObjectDecoder(
int maxInitialLineLength, int maxHeaderSize, int maxChunkSize,
boolean chunkedSupported, boolean validateHeaders, int initialBufferSize) {
checkPositive(maxInitialLineLength, "maxInitialLineLength");
checkPositive(maxHeaderSize, "maxHeaderSize");
checkPositive(maxChunkSize, "maxChunkSize");
AppendableCharSequence seq = new AppendableCharSequence(initialBufferSize);
lineParser = new LineParser(seq, maxInitialLineLength);
headerParser = new HeaderParser(seq, maxHeaderSize);
this.maxChunkSize = maxChunkSize;
this.chunkedSupported = chunkedSupported;
this.validateHeaders = validateHeaders;
}
@Override
protected void decode(ChannelHandlerContext ctx, ByteBuf buffer, List<Object> out) throws Exception {
if (resetRequested) {
resetNow();
}
switch (currentState) {
case SKIP_CONTROL_CHARS:
// Fall-through
case READ_INITIAL: try {
AppendableCharSequence line = lineParser.parse(buffer);
if (line == null) {
return;
}
String[] initialLine = splitInitialLine(line);
if (initialLine.length < 3) {
// Invalid initial line - ignore.
currentState = State.SKIP_CONTROL_CHARS;
return;
}
message = createMessage(initialLine);
currentState = State.READ_HEADER;
// fall-through
} catch (Exception e) {
out.add(invalidMessage(buffer, e));
return;
}
case READ_HEADER: try {
State nextState = readHeaders(buffer);
if (nextState == null) {
return;
}
currentState = nextState;
switch (nextState) {
case SKIP_CONTROL_CHARS:
// fast-path
// No content is expected.
out.add(message);
out.add(LastHttpContent.EMPTY_LAST_CONTENT);
resetNow();
return;
case READ_CHUNK_SIZE:
if (!chunkedSupported) {
throw new IllegalArgumentException("Chunked messages not supported");
}
// Chunked encoding - generate HttpMessage first. HttpChunks will follow.
out.add(message);
return;
default:
/**
* <a href="https://tools.ietf.org/html/rfc7230#section-3.3.3">RFC 7230, 3.3.3</a> states that if a
* request does not have either a transfer-encoding or a content-length header then the message body
* length is 0. However for a response the body length is the number of octets received prior to the
* server closing the connection. So we treat this as variable length chunked encoding.
*/
long contentLength = contentLength();
if (contentLength == 0 || contentLength == -1 && isDecodingRequest()) {
out.add(message);
out.add(LastHttpContent.EMPTY_LAST_CONTENT);
resetNow();
return;
}
assert nextState == State.READ_FIXED_LENGTH_CONTENT ||
nextState == State.READ_VARIABLE_LENGTH_CONTENT;
out.add(message);
if (nextState == State.READ_FIXED_LENGTH_CONTENT) {
// chunkSize will be decreased as the READ_FIXED_LENGTH_CONTENT state reads data chunk by chunk.
chunkSize = contentLength;
}
// We return here, this forces decode to be called again where we will decode the content
return;
}
} catch (Exception e) {
out.add(invalidMessage(buffer, e));
return;
}
case READ_VARIABLE_LENGTH_CONTENT: {
// Keep reading data as a chunk until the end of connection is reached.
int toRead = Math.min(buffer.readableBytes(), maxChunkSize);
if (toRead > 0) {
ByteBuf content = buffer.readRetainedSlice(toRead);
out.add(new DefaultHttpContent(content));
}
return;
}
case READ_FIXED_LENGTH_CONTENT: {
int readLimit = buffer.readableBytes();
// Check if the buffer is readable first as we use the readable byte count
// to create the HttpChunk. This is needed as otherwise we may end up with
// create an HttpChunk instance that contains an empty buffer and so is
// handled like it is the last HttpChunk.
//
// See https://github.com/netty/netty/issues/433
if (readLimit == 0) {
return;
}
int toRead = Math.min(readLimit, maxChunkSize);
if (toRead > chunkSize) {
toRead = (int) chunkSize;
}
ByteBuf content = buffer.readRetainedSlice(toRead);
chunkSize -= toRead;
if (chunkSize == 0) {
// Read all content.
out.add(new DefaultLastHttpContent(content, validateHeaders));
resetNow();
} else {
out.add(new DefaultHttpContent(content));
}
return;
}
/**
* everything else after this point takes care of reading chunked content. basically, read chunk size,
* read chunk, read and ignore the CRLF and repeat until 0
*/
case READ_CHUNK_SIZE: try {
AppendableCharSequence line = lineParser.parse(buffer);
if (line == null) {
return;
}
int chunkSize = getChunkSize(line.toString());
this.chunkSize = chunkSize;
if (chunkSize == 0) {
currentState = State.READ_CHUNK_FOOTER;
return;
}
currentState = State.READ_CHUNKED_CONTENT;
// fall-through
} catch (Exception e) {
out.add(invalidChunk(buffer, e));
return;
}
case READ_CHUNKED_CONTENT: {
assert chunkSize <= Integer.MAX_VALUE;
int toRead = Math.min((int) chunkSize, maxChunkSize);
toRead = Math.min(toRead, buffer.readableBytes());
if (toRead == 0) {
return;
}
HttpContent chunk = new DefaultHttpContent(buffer.readRetainedSlice(toRead));
chunkSize -= toRead;
out.add(chunk);
if (chunkSize != 0) {
return;
}
currentState = State.READ_CHUNK_DELIMITER;
// fall-through
}
case READ_CHUNK_DELIMITER: {
final int wIdx = buffer.writerIndex();
int rIdx = buffer.readerIndex();
while (wIdx > rIdx) {
byte next = buffer.getByte(rIdx++);
if (next == HttpConstants.LF) {
currentState = State.READ_CHUNK_SIZE;
break;
}
}
buffer.readerIndex(rIdx);
return;
}
case READ_CHUNK_FOOTER: try {
LastHttpContent trailer = readTrailingHeaders(buffer);
if (trailer == null) {
return;
}
out.add(trailer);
resetNow();
return;
} catch (Exception e) {
out.add(invalidChunk(buffer, e));
return;
}
case BAD_MESSAGE: {
// Keep discarding until disconnection.
buffer.skipBytes(buffer.readableBytes());
break;
}
case UPGRADED: {
int readableBytes = buffer.readableBytes();
if (readableBytes > 0) {
// Keep on consuming as otherwise we may trigger an DecoderException,
// other handler will replace this codec with the upgraded protocol codec to
// take the traffic over at some point then.
// See https://github.com/netty/netty/issues/2173
out.add(buffer.readBytes(readableBytes));
}
break;
}
}
}
@Override
protected void decodeLast(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
super.decodeLast(ctx, in, out);
if (resetRequested) {
// If a reset was requested by decodeLast() we need to do it now otherwise we may produce a
// LastHttpContent while there was already one.
resetNow();
}
// Handle the last unfinished message.
if (message != null) {
boolean chunked = HttpUtil.isTransferEncodingChunked(message);
if (currentState == State.READ_VARIABLE_LENGTH_CONTENT && !in.isReadable() && !chunked) {
// End of connection.
out.add(LastHttpContent.EMPTY_LAST_CONTENT);
resetNow();
return;
}
if (currentState == State.READ_HEADER) {
// If we are still in the state of reading headers we need to create a new invalid message that
// signals that the connection was closed before we received the headers.
out.add(invalidMessage(Unpooled.EMPTY_BUFFER,
new PrematureChannelClosureException("Connection closed before received headers")));
resetNow();
return;
}
// Check if the closure of the connection signifies the end of the content.
boolean prematureClosure;
if (isDecodingRequest() || chunked) {
// The last request did not wait for a response.
prematureClosure = true;
} else {
// Compare the length of the received content and the 'Content-Length' header.
// If the 'Content-Length' header is absent, the length of the content is determined by the end of the
// connection, so it is perfectly fine.
prematureClosure = contentLength() > 0;
}
if (!prematureClosure) {
out.add(LastHttpContent.EMPTY_LAST_CONTENT);
}
resetNow();
}
}
@Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
if (evt instanceof HttpExpectationFailedEvent) {
switch (currentState) {
case READ_FIXED_LENGTH_CONTENT:
case READ_VARIABLE_LENGTH_CONTENT:
case READ_CHUNK_SIZE:
reset();
break;
default:
break;
}
}
super.userEventTriggered(ctx, evt);
}
protected boolean isContentAlwaysEmpty(HttpMessage msg) {
if (msg instanceof HttpResponse) {
HttpResponse res = (HttpResponse) msg;
int code = res.status().code();
// Correctly handle return codes of 1xx.
//
// See:
// - http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html Section 4.4
// - https://github.com/netty/netty/issues/222
if (code >= 100 && code < 200) {
// One exception: Hixie 76 websocket handshake response
return !(code == 101 && !res.headers().contains(HttpHeaderNames.SEC_WEBSOCKET_ACCEPT)
&& res.headers().contains(HttpHeaderNames.UPGRADE, HttpHeaderValues.WEBSOCKET, true));
}
switch (code) {
case 204: case 304:
return true;
}
}
return false;
}
/**
* Returns true if the server switched to a different protocol than HTTP/1.0 or HTTP/1.1, e.g. HTTP/2 or Websocket.
* Returns false if the upgrade happened in a different layer, e.g. upgrade from HTTP/1.1 to HTTP/1.1 over TLS.
*/
protected boolean isSwitchingToNonHttp1Protocol(HttpResponse msg) {
if (msg.status().code() != HttpResponseStatus.SWITCHING_PROTOCOLS.code()) {
return false;
}
String newProtocol = msg.headers().get(HttpHeaderNames.UPGRADE);
return newProtocol == null ||
!newProtocol.contains(HttpVersion.HTTP_1_0.text()) &&
!newProtocol.contains(HttpVersion.HTTP_1_1.text());
}
/**
* Resets the state of the decoder so that it is ready to decode a new message.
* This method is useful for handling a rejected request with {@code Expect: 100-continue} header.
*/
public void reset() {
resetRequested = true;
}
private void resetNow() {
HttpMessage message = this.message;
this.message = null;
name = null;
value = null;
contentLength = Long.MIN_VALUE;
lineParser.reset();
headerParser.reset();
trailer = null;
if (!isDecodingRequest()) {
HttpResponse res = (HttpResponse) message;
if (res != null && isSwitchingToNonHttp1Protocol(res)) {
currentState = State.UPGRADED;
return;
}
}
resetRequested = false;
currentState = State.SKIP_CONTROL_CHARS;
}
private HttpMessage invalidMessage(ByteBuf in, Exception cause) {
currentState = State.BAD_MESSAGE;
// Advance the readerIndex so that ByteToMessageDecoder does not complain
// when we produced an invalid message without consuming anything.
in.skipBytes(in.readableBytes());
if (message == null) {
message = createInvalidMessage();
}
message.setDecoderResult(DecoderResult.failure(cause));
HttpMessage ret = message;
message = null;
return ret;
}
private HttpContent invalidChunk(ByteBuf in, Exception cause) {
currentState = State.BAD_MESSAGE;
// Advance the readerIndex so that ByteToMessageDecoder does not complain
// when we produced an invalid message without consuming anything.
in.skipBytes(in.readableBytes());
HttpContent chunk = new DefaultLastHttpContent(Unpooled.EMPTY_BUFFER);
chunk.setDecoderResult(DecoderResult.failure(cause));
message = null;
trailer = null;
return chunk;
}
private State readHeaders(ByteBuf buffer) {
final HttpMessage message = this.message;
final HttpHeaders headers = message.headers();
AppendableCharSequence line = headerParser.parse(buffer);
if (line == null) {
return null;
}
if (line.length() > 0) {
do {
char firstChar = line.charAtUnsafe(0);
if (name != null && (firstChar == ' ' || firstChar == '\t')) {
//please do not make one line from below code
//as it breaks +XX:OptimizeStringConcat optimization
String trimmedLine = line.toString().trim();
String valueStr = String.valueOf(value);
value = valueStr + ' ' + trimmedLine;
} else {
if (name != null) {
headers.add(name, value);
}
splitHeader(line);
}
line = headerParser.parse(buffer);
if (line == null) {
return null;
}
} while (line.length() > 0);
}
// Add the last header.
if (name != null) {
headers.add(name, value);
}
// reset name and value fields
name = null;
value = null;
List<String> values = headers.getAll(HttpHeaderNames.CONTENT_LENGTH);
int contentLengthValuesCount = values.size();
if (contentLengthValuesCount > 0) {
// Guard against multiple Content-Length headers as stated in
// https://tools.ietf.org/html/rfc7230#section-3.3.2:
//
// If a message is received that has multiple Content-Length header
// fields with field-values consisting of the same decimal value, or a
// single Content-Length header field with a field value containing a
// list of identical decimal values (e.g., "Content-Length: 42, 42"),
// indicating that duplicate Content-Length header fields have been
// generated or combined by an upstream message processor, then the
// recipient MUST either reject the message as invalid or replace the
// duplicated field-values with a single valid Content-Length field
// containing that decimal value prior to determining the message body
// length or forwarding the message.
if (contentLengthValuesCount > 1 && message.protocolVersion() == HttpVersion.HTTP_1_1) {
throw new IllegalArgumentException("Multiple Content-Length headers found");
}
contentLength = Long.parseLong(values.get(0));
}
if (isContentAlwaysEmpty(message)) {
HttpUtil.setTransferEncodingChunked(message, false);
return State.SKIP_CONTROL_CHARS;
} else if (HttpUtil.isTransferEncodingChunked(message)) {
if (contentLengthValuesCount > 0 && message.protocolVersion() == HttpVersion.HTTP_1_1) {
handleTransferEncodingChunkedWithContentLength(message);
}
return State.READ_CHUNK_SIZE;
} else if (contentLength() >= 0) {
return State.READ_FIXED_LENGTH_CONTENT;
} else {
return State.READ_VARIABLE_LENGTH_CONTENT;
}
}
/**
* Invoked when a message with both a "Transfer-Encoding: chunked" and a "Content-Length" header field is detected.
* The default behavior is to <i>remove</i> the Content-Length field, but this method could be overridden
* to change the behavior (to, e.g., throw an exception and produce an invalid message).
* <p>
* See: https://tools.ietf.org/html/rfc7230#section-3.3.3
* <pre>
* If a message is received with both a Transfer-Encoding and a
* Content-Length header field, the Transfer-Encoding overrides the
* Content-Length. Such a message might indicate an attempt to
* perform request smuggling (Section 9.5) or response splitting
* (Section 9.4) and ought to be handled as an error. A sender MUST
* remove the received Content-Length field prior to forwarding such
* a message downstream.
* </pre>
* Also see:
* https://github.com/apache/tomcat/blob/b693d7c1981fa7f51e58bc8c8e72e3fe80b7b773/
* java/org/apache/coyote/http11/Http11Processor.java#L747-L755
* https://github.com/nginx/nginx/blob/0ad4393e30c119d250415cb769e3d8bc8dce5186/
* src/http/ngx_http_request.c#L1946-L1953
*/
protected void handleTransferEncodingChunkedWithContentLength(HttpMessage message) {
message.headers().remove(HttpHeaderNames.CONTENT_LENGTH);
contentLength = Long.MIN_VALUE;
}
private long contentLength() {
if (contentLength == Long.MIN_VALUE) {
contentLength = HttpUtil.getContentLength(message, -1L);
}
return contentLength;
}
private LastHttpContent readTrailingHeaders(ByteBuf buffer) {
AppendableCharSequence line = headerParser.parse(buffer);
if (line == null) {
return null;
}
LastHttpContent trailer = this.trailer;
if (line.length() == 0 && trailer == null) {
// We have received the empty line which signals the trailer is complete and did not parse any trailers
// before. Just return an empty last content to reduce allocations.
return LastHttpContent.EMPTY_LAST_CONTENT;
}
CharSequence lastHeader = null;
if (trailer == null) {
trailer = this.trailer = new DefaultLastHttpContent(Unpooled.EMPTY_BUFFER, validateHeaders);
}
while (line.length() > 0) {
char firstChar = line.charAtUnsafe(0);
if (lastHeader != null && (firstChar == ' ' || firstChar == '\t')) {
List<String> current = trailer.trailingHeaders().getAll(lastHeader);
if (!current.isEmpty()) {
int lastPos = current.size() - 1;
//please do not make one line from below code
//as it breaks +XX:OptimizeStringConcat optimization
String lineTrimmed = line.toString().trim();
String currentLastPos = current.get(lastPos);
current.set(lastPos, currentLastPos + lineTrimmed);
}
} else {
splitHeader(line);
CharSequence headerName = name;
if (!HttpHeaderNames.CONTENT_LENGTH.contentEqualsIgnoreCase(headerName) &&
!HttpHeaderNames.TRANSFER_ENCODING.contentEqualsIgnoreCase(headerName) &&
!HttpHeaderNames.TRAILER.contentEqualsIgnoreCase(headerName)) {
trailer.trailingHeaders().add(headerName, value);
}
lastHeader = name;
// reset name and value fields
name = null;
value = null;
}
line = headerParser.parse(buffer);
if (line == null) {
return null;
}
}
this.trailer = null;
return trailer;
}
protected abstract boolean isDecodingRequest();
protected abstract HttpMessage createMessage(String[] initialLine) throws Exception;
protected abstract HttpMessage createInvalidMessage();
private static int getChunkSize(String hex) {
hex = hex.trim();
for (int i = 0; i < hex.length(); i ++) {
char c = hex.charAt(i);
if (c == ';' || Character.isWhitespace(c) || Character.isISOControl(c)) {
hex = hex.substring(0, i);
break;
}
}
return Integer.parseInt(hex, 16);
}
private static String[] splitInitialLine(AppendableCharSequence sb) {
int aStart;
int aEnd;
int bStart;
int bEnd;
int cStart;
int cEnd;
aStart = findNonSPLenient(sb, 0);
aEnd = findSPLenient(sb, aStart);
bStart = findNonSPLenient(sb, aEnd);
bEnd = findSPLenient(sb, bStart);
cStart = findNonSPLenient(sb, bEnd);
cEnd = findEndOfString(sb);
return new String[] {
sb.subStringUnsafe(aStart, aEnd),
sb.subStringUnsafe(bStart, bEnd),
cStart < cEnd? sb.subStringUnsafe(cStart, cEnd) : "" };
}
private void splitHeader(AppendableCharSequence sb) {
final int length = sb.length();
int nameStart;
int nameEnd;
int colonEnd;
int valueStart;
int valueEnd;
nameStart = findNonWhitespace(sb, 0, false);
for (nameEnd = nameStart; nameEnd < length; nameEnd ++) {
char ch = sb.charAtUnsafe(nameEnd);
// https://tools.ietf.org/html/rfc7230#section-3.2.4
//
// No whitespace is allowed between the header field-name and colon. In
// the past, differences in the handling of such whitespace have led to
// security vulnerabilities in request routing and response handling. A
// server MUST reject any received request message that contains
// whitespace between a header field-name and colon with a response code
// of 400 (Bad Request). A proxy MUST remove any such whitespace from a
// response message before forwarding the message downstream.
if (ch == ':' ||
// In case of decoding a request we will just continue processing and header validation
// is done in the DefaultHttpHeaders implementation.
//
// In the case of decoding a response we will "skip" the whitespace.
(!isDecodingRequest() && isOWS(ch))) {
break;
}
}
if (nameEnd == length) {
// There was no colon present at all.
throw new IllegalArgumentException("No colon found");
}
for (colonEnd = nameEnd; colonEnd < length; colonEnd ++) {
if (sb.charAtUnsafe(colonEnd) == ':') {
colonEnd ++;
break;
}
}
name = sb.subStringUnsafe(nameStart, nameEnd);
valueStart = findNonWhitespace(sb, colonEnd, true);
if (valueStart == length) {
value = EMPTY_VALUE;
} else {
valueEnd = findEndOfString(sb);
value = sb.subStringUnsafe(valueStart, valueEnd);
}
}
private static int findNonSPLenient(AppendableCharSequence sb, int offset) {
for (int result = offset; result < sb.length(); ++result) {
char c = sb.charAtUnsafe(result);
// See https://tools.ietf.org/html/rfc7230#section-3.5
if (isSPLenient(c)) {
continue;
}
if (Character.isWhitespace(c)) {
// Any other whitespace delimiter is invalid
throw new IllegalArgumentException("Invalid separator");
}
return result;
}
return sb.length();
}
private static int findSPLenient(AppendableCharSequence sb, int offset) {
for (int result = offset; result < sb.length(); ++result) {
if (isSPLenient(sb.charAtUnsafe(result))) {
return result;
}
}
return sb.length();
}
private static boolean isSPLenient(char c) {
// See https://tools.ietf.org/html/rfc7230#section-3.5
return c == ' ' || c == (char) 0x09 || c == (char) 0x0B || c == (char) 0x0C || c == (char) 0x0D;
}
private static int findNonWhitespace(AppendableCharSequence sb, int offset, boolean validateOWS) {
for (int result = offset; result < sb.length(); ++result) {
char c = sb.charAtUnsafe(result);
if (!Character.isWhitespace(c)) {
return result;
} else if (validateOWS && !isOWS(c)) {
// Only OWS is supported for whitespace
throw new IllegalArgumentException("Invalid separator, only a single space or horizontal tab allowed," +
" but received a '" + c + "'");
}
}
return sb.length();
}
private static int findEndOfString(AppendableCharSequence sb) {
for (int result = sb.length() - 1; result > 0; --result) {
if (!Character.isWhitespace(sb.charAtUnsafe(result))) {
return result + 1;
}
}
return 0;
}
private static boolean isOWS(char ch) {
return ch == ' ' || ch == (char) 0x09;
}
private static class HeaderParser implements ByteProcessor {
private final AppendableCharSequence seq;
private final int maxLength;
private int size;
HeaderParser(AppendableCharSequence seq, int maxLength) {
this.seq = seq;
this.maxLength = maxLength;
}
public AppendableCharSequence parse(ByteBuf buffer) {
final int oldSize = size;
seq.reset();
int i = buffer.forEachByte(this);
if (i == -1) {
size = oldSize;
return null;
}
buffer.readerIndex(i + 1);
return seq;
}
public void reset() {
size = 0;
}
@Override
public boolean process(byte value) throws Exception {
char nextByte = (char) (value & 0xFF);
if (nextByte == HttpConstants.LF) {
int len = seq.length();
// Drop CR if we had a CRLF pair
if (len >= 1 && seq.charAtUnsafe(len - 1) == HttpConstants.CR) {
-- size;
seq.setLength(len - 1);
}
return false;
}
increaseCount();
seq.append(nextByte);
return true;
}
protected final void increaseCount() {
if (++ size > maxLength) {
// TODO: Respond with Bad Request and discard the traffic
// or close the connection.
// No need to notify the upstream handlers - just log.
// If decoding a response, just throw an exception.
throw newException(maxLength);
}
}
protected TooLongFrameException newException(int maxLength) {
return new TooLongFrameException("HTTP header is larger than " + maxLength + " bytes.");
}
}
private final class LineParser extends HeaderParser {
LineParser(AppendableCharSequence seq, int maxLength) {
super(seq, maxLength);
}
@Override
public AppendableCharSequence parse(ByteBuf buffer) {
reset();
return super.parse(buffer);
}
@Override
public boolean process(byte value) throws Exception {
if (currentState == State.SKIP_CONTROL_CHARS) {
char c = (char) (value & 0xFF);
if (Character.isISOControl(c) || Character.isWhitespace(c)) {
increaseCount();
return true;
}
currentState = State.READ_INITIAL;
}
return super.process(value);
}
@Override
protected TooLongFrameException newException(int maxLength) {
return new TooLongFrameException("An HTTP line is larger than " + maxLength + " bytes.");
}
}
}