Class HAProxyMessageDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder

io.netty.handler.codec.haproxy.HAProxyMessageDecoder

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler

public class HAProxyMessageDecoder
extends ByteToMessageDecoder

Decodes an HAProxy proxy protocol header

See Also:

• Proxy Protocol Specification

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private class	HAProxyMessageDecoder.HeaderExtractor	HeaderExtractor create a header frame out of the ByteBuf.
private final class	HAProxyMessageDecoder.LineHeaderExtractor
private final class	HAProxyMessageDecoder.StructHeaderExtractor

Nested classes/interfaces inherited from class ByteToMessageDecoder

ByteToMessageDecoder.Cumulator

Nested classes/interfaces inherited from interface ChannelHandler

ChannelHandler.Sharable

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	BINARY_PREFIX_LENGTH	Binary header prefix length
private static final ProtocolDetectionResult<HAProxyProtocolVersion>	DETECTION_RESULT_V1	ProtocolDetectionResult for HAProxyProtocolVersion.V1.
private static final ProtocolDetectionResult<HAProxyProtocolVersion>	DETECTION_RESULT_V2	ProtocolDetectionResult for HAProxyProtocolVersion.V2.
private int	discardedBytes	Number of discarded bytes
private boolean	discarding	true if we're discarding input because we're already over maxLength
private final boolean	failFast	Whether or not to throw an exception as soon as we exceed maxLength.
private boolean	finished	true if we're finished decoding the proxy protocol header
private HAProxyMessageDecoder.HeaderExtractor	headerExtractor	Used to extract a header frame out of the ByteBuf and return it.
private static final int	V1_MAX_LENGTH	Maximum possible length of a v1 proxy protocol header per spec
private static final int	V2_MAX_LENGTH	Maximum possible length of a v2 proxy protocol header (fixed 16 bytes + max unsigned short)
private static final int	V2_MAX_TLV	Maximum possible length for v2 additional TLV data (max unsigned short - max v2 address info space)
private static final int	V2_MIN_LENGTH	Minimum possible length of a fully functioning v2 proxy protocol header (fixed 16 bytes + v2 address info space)
private final int	v2MaxHeaderSize	The latest v2 spec (2014/05/18) allows for additional data to be sent in the proxy protocol header beyond the address information block so now we need a configurable max header size
private int	version	Protocol specification version

Fields inherited from class ByteToMessageDecoder

COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Constructor Summary

Constructors

Constructor	Description
HAProxyMessageDecoder()	Creates a new decoder with no additional data (TLV) restrictions, and should throw an exception as soon as we exceed maxLength.
HAProxyMessageDecoder(boolean failFast)	Creates a new decoder with no additional data (TLV) restrictions, whether or not to throw an exception as soon as we exceed maxLength.
HAProxyMessageDecoder(int maxTlvSize)	Creates a new decoder with restricted additional data (TLV) size, and should throw an exception as soon as we exceed maxLength.
HAProxyMessageDecoder(int maxTlvSize, boolean failFast)	Creates a new decoder with restricted additional data (TLV) size, whether or not to throw an exception as soon as we exceed maxLength.

Method Summary

Modifier and Type	Method	Description
void	channelRead(ChannelHandlerContext ctx, Object msg)	Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline.
protected final void	decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out)	Decode the from one ByteBuf to an other.
private ByteBuf	decodeLine(ChannelHandlerContext ctx, ByteBuf buffer)	Create a frame out of the ByteBuf and return it.
private ByteBuf	decodeStruct(ChannelHandlerContext ctx, ByteBuf buffer)	Create a frame out of the ByteBuf and return it.
static ProtocolDetectionResult<HAProxyProtocolVersion>	detectProtocol(ByteBuf buffer)	Returns the ProtocolDetectionResult for the given ByteBuf.
private void	fail(ChannelHandlerContext ctx, String errMsg, Exception e)
private void	failOverLimit(ChannelHandlerContext ctx, int length)
private void	failOverLimit(ChannelHandlerContext ctx, String length)
private static int	findEndOfHeader(ByteBuf buffer)	Returns the index in the buffer of the end of header if found.
private static int	findEndOfLine(ByteBuf buffer)	Returns the index in the buffer of the end of line found.
private static int	findVersion(ByteBuf buffer)	Returns the proxy protocol specification version in the buffer if the version is found.
boolean	isSingleDecode()	If true then only one message is decoded on each ByteToMessageDecoder.channelRead(ChannelHandlerContext, Object) call.
private static boolean	match(byte[] prefix, ByteBuf buffer, int idx)

Methods inherited from class ByteToMessageDecoder

actualReadableBytes, callDecode, channelInactive, channelReadComplete, decodeLast, discardSomeReadBytes, handlerRemoved, handlerRemoved0, internalBuffer, setCumulator, setDiscardAfterReads, setSingleDecode, userEventTriggered

Methods inherited from class ChannelInboundHandlerAdapter

channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught

Methods inherited from class ChannelHandlerAdapter

ensureNotSharable, handlerAdded, isSharable

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface ChannelHandler

handlerAdded

Field Details

V1_MAX_LENGTH

private static final int V1_MAX_LENGTH

Maximum possible length of a v1 proxy protocol header per spec

See Also:

• Constant Field Values

V2_MAX_LENGTH

private static final int V2_MAX_LENGTH

Maximum possible length of a v2 proxy protocol header (fixed 16 bytes + max unsigned short)

See Also:

• Constant Field Values

V2_MIN_LENGTH

private static final int V2_MIN_LENGTH

Minimum possible length of a fully functioning v2 proxy protocol header (fixed 16 bytes + v2 address info space)

See Also:

• Constant Field Values

V2_MAX_TLV

private static final int V2_MAX_TLV

Maximum possible length for v2 additional TLV data (max unsigned short - max v2 address info space)

See Also:

• Constant Field Values

BINARY_PREFIX_LENGTH

private static final int BINARY_PREFIX_LENGTH

Binary header prefix length

DETECTION_RESULT_V1

private static final ProtocolDetectionResult<HAProxyProtocolVersion> DETECTION_RESULT_V1

ProtocolDetectionResult for HAProxyProtocolVersion.V1.

DETECTION_RESULT_V2

private static final ProtocolDetectionResult<HAProxyProtocolVersion> DETECTION_RESULT_V2

ProtocolDetectionResult for HAProxyProtocolVersion.V2.

headerExtractor

private HAProxyMessageDecoder.HeaderExtractor headerExtractor

Used to extract a header frame out of the ByteBuf and return it.

discarding

private boolean discarding

true if we're discarding input because we're already over maxLength

discardedBytes

private int discardedBytes

Number of discarded bytes

failFast

private final boolean failFast

Whether or not to throw an exception as soon as we exceed maxLength.

finished

private boolean finished

true if we're finished decoding the proxy protocol header

version

private int version

Protocol specification version

v2MaxHeaderSize

private final int v2MaxHeaderSize

The latest v2 spec (2014/05/18) allows for additional data to be sent in the proxy protocol header beyond the address information block so now we need a configurable max header size

Constructor Details

HAProxyMessageDecoder

public HAProxyMessageDecoder()

Creates a new decoder with no additional data (TLV) restrictions, and should throw an exception as soon as we exceed maxLength.

HAProxyMessageDecoder

public HAProxyMessageDecoder(boolean failFast)

Creates a new decoder with no additional data (TLV) restrictions, whether or not to throw an exception as soon as we exceed maxLength.

Parameters:

failFast - Whether or not to throw an exception as soon as we exceed maxLength

HAProxyMessageDecoder

public HAProxyMessageDecoder(int maxTlvSize)

Creates a new decoder with restricted additional data (TLV) size, and should throw an exception as soon as we exceed maxLength.

Note: limiting TLV size only affects processing of v2, binary headers. Also, as allowed by the 1.5 spec TLV data is currently ignored. For maximum performance it would be best to configure your upstream proxy host to NOT send TLV data and instantiate with a max TLV size of 0.

Parameters:

maxTlvSize - maximum number of bytes allowed for additional data (Type-Length-Value vectors) in a v2 header

HAProxyMessageDecoder

public HAProxyMessageDecoder(int maxTlvSize,
 boolean failFast)

Creates a new decoder with restricted additional data (TLV) size, whether or not to throw an exception as soon as we exceed maxLength.

Parameters:

maxTlvSize - maximum number of bytes allowed for additional data (Type-Length-Value vectors) in a v2 header

failFast - Whether or not to throw an exception as soon as we exceed maxLength

Method Details

findVersion

private static int findVersion(ByteBuf buffer)

Returns the proxy protocol specification version in the buffer if the version is found. Returns -1 if no version was found in the buffer.

findEndOfHeader

private static int findEndOfHeader(ByteBuf buffer)

Returns the index in the buffer of the end of header if found. Returns -1 if no end of header was found in the buffer.

findEndOfLine

private static int findEndOfLine(ByteBuf buffer)

Returns the index in the buffer of the end of line found. Returns -1 if no end of line was found in the buffer.

isSingleDecode

public boolean isSingleDecode()

Description copied from class: ByteToMessageDecoder

If true then only one message is decoded on each ByteToMessageDecoder.channelRead(ChannelHandlerContext, Object) call. Default is false as this has performance impacts.

Overrides:

isSingleDecode in class ByteToMessageDecoder

channelRead

public void channelRead(ChannelHandlerContext ctx,
 Object msg)
                 throws Exception

Description copied from class: ChannelInboundHandlerAdapter

Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

channelRead in interface ChannelInboundHandler

Overrides:

channelRead in class ByteToMessageDecoder

Throws:

Exception

decode

protected final void decode(ChannelHandlerContext ctx,
 ByteBuf in,
 List<Object> out)
                     throws Exception

Description copied from class: ByteToMessageDecoder

Decode the from one ByteBuf to an other. This method will be called till either the input ByteBuf has nothing to read when return from this method or till nothing was read from the input ByteBuf.

Specified by:

decode in class ByteToMessageDecoder

Parameters:

ctx - the ChannelHandlerContext which this ByteToMessageDecoder belongs to

in - the ByteBuf from which to read data

out - the List to which decoded messages should be added

Throws:

Exception - is thrown if an error occurs

decodeStruct

private ByteBuf decodeStruct(ChannelHandlerContext ctx,
 ByteBuf buffer)
                      throws Exception

Create a frame out of the ByteBuf and return it.

Parameters:

ctx - the ChannelHandlerContext which this HAProxyMessageDecoder belongs to

buffer - the ByteBuf from which to read data

Returns:

frame the ByteBuf which represent the frame or null if no frame could be created

Throws:

Exception

decodeLine

private ByteBuf decodeLine(ChannelHandlerContext ctx,
 ByteBuf buffer)
                    throws Exception

Create a frame out of the ByteBuf and return it.

Parameters:

ctx - the ChannelHandlerContext which this HAProxyMessageDecoder belongs to

buffer - the ByteBuf from which to read data

Returns:

frame the ByteBuf which represent the frame or null if no frame could be created

Throws:

Exception

failOverLimit

private void failOverLimit(ChannelHandlerContext ctx,
 int length)

failOverLimit

private void failOverLimit(ChannelHandlerContext ctx,
 String length)

fail

private void fail(ChannelHandlerContext ctx,
 String errMsg,
 Exception e)

detectProtocol

public static ProtocolDetectionResult<HAProxyProtocolVersion> detectProtocol(ByteBuf buffer)

Returns the ProtocolDetectionResult for the given ByteBuf.

match

private static boolean match(byte[] prefix,
 ByteBuf buffer,
 int idx)