Motivation:
There is a race between both flushing the upgrade response and receiving
more data before the flush ChannelPromise can fire and reshape the
pipeline. Since We have already committed to an upgrade by writing the
upgrade response, we need to be immediately prepared for handling the
next protocol.
Modifications:
The pipeline reshaping logic in HttpServerUpgradeHandler has been moved
out of the ChannelFutureListener attached to the write of the upgrade
response and happens immediately after the writeAndFlush call, but
before the method returns.
Result:
The pipeline is no longer subject to receiving more data before the
pipeline has been reformed.
Motivation:
We did not correctly set the stream id in the headers of HttpMessage when converting a Http2HeadersFrame. This is based on https://github.com/netty/netty/pull/7778 so thanks to @jprante.
Modifications:
- Correctly set the id when possible in the header.
- Add test case
Result:
Correctly include stream id.
Motivation:
Allow the observation of SETTINGS frame by other handlers in the pipeline. For my particular use case this allows me to observe the value of MAX_CONCURRENT_STREAMS for a ChannelPool abstraction that supports HTTP/2 multiplexing. Beside this also forward GOAWAY frames.
Modification:
Always forward SETTINGS and GOAWAY frames
Result:
Settings / Goaway can now be observed in the parent channel. Previously it was not possible (to my knowledge) to capture the settings when using Http2MultiplexCodec.
Motivation:
At the moment we use a ByteBuf as the payload for a http2 frame. This complicates life-time management a lot with no real gain and also may produce more objects then needed. We should just use a long as it is required to be 8 bytes anyway.
Modifications:
Use long for ping payloads.
Result:
Fixes [#7629].
Motivation:
Reflective setAccessible(true) will produce scary warnings on the console when using java9+, while netty still works. That said users may feel uncomfortable with these warnings, we should not try to do it by default when using java9+.
Modifications:
Add io.netty.tryReflectionSetAccessible system property which controls if setAccessible(...) will be used. By default it will bet set to false when using java9+.
Result:
Fixes [#7254].
Motivation:
According to the spec:
All pseudo-header fields MUST appear in the header block before regular
header fields. Any request or response that contains a pseudo-header
field that appears in a header block after
a regular header field MUST be treated as malformed (Section 8.1.2.6).
Pseudo-header fields are only valid in the context in which they are defined.
Pseudo-header fields defined for requests MUST NOT appear in responses;
pseudo-header fields defined for responses MUST NOT appear in requests.
Pseudo-header fields MUST NOT appear in trailers.
Endpoints MUST treat a request or response that contains undefined or
invalid pseudo-header fields as malformed (Section 8.1.2.6).
Clients MUST NOT accept a malformed response. Note that these requirements
are intended to protect against several types of common attacks against HTTP;
they are deliberately strict because being permissive can expose
implementations to these vulnerabilities.
Modifications:
- Introduce validation in HPackDecoder
Result:
- Requests with unknown pseudo-field headers are rejected
- Requests with containing response specific pseudo-headers are rejected
- Requests where pseudo-header appear after regular header are rejected
- h2spec 8.1.2.1 pass
Motivation:
We should convert Http2Exceptions that are produced because of STREAM_CLOSED to ClosedChannelException when hand-over to the child channel to make it more consistent with other transports.
Modifications:
- Check if STREAM_CLOSED is used and if so create a new ClosedChannelException (while preserve the original exception as cause) and use it in the child channel
- Ensure STREAM_CLOSED is used in DefaultHttp2RemoteFlowController when writes are failed because of a closed stream.
- Add testcase
Result:
More consistent and correct exception usage.
Motivation:
When checking if a value is present, ReadOnlyHttp2Headers always ignores
case for values.
RFC 7540 says: https://tools.ietf.org/html/rfc7540#section-8.1.2
"header field names are strings of ASCII characters that are compared in a case-insensitive fashion"
But there is no such constraint on header values
Modifications:
Updated ReadOnlyHttp2Headers.contains to compare header value in a
case-sensitive way.
Result:
ReadOnlyHttp2Headers compares header names in a case-insensitive way,
values in a case-sensitive way.
Motivation:
If you test a header value providing a String, contains() returns false.
This is due to the implementation inherited from DefaultHeaders using
the JAVA_HASHER.
JAVA_HASHER.equals returns false because a is a String and b an
AsciiString.
Modifications:
DefaultHttp2Headers overrides contains and uses CASE_SENSITIVE_HASHER.
Result:
You can test a header value with any CharSequence implementation.
Motivation:
The completion order of promises in Http2MultiplexChannel#close should be consistent with that of AbstractChannel. Otherwise this may result in Future listeners seeing incorrect channel state.
Modifications:
Add tests cases.
Result:
Ensure consistent behavior between Http2MultiplexChannel and AbstractChannel.
Motivation:
Calling DefaultHttp2StreamChannel.Unsafe.close(...) multiple times should not fail.
Modification:
- Correctly handle multiple calls to DefaultHttp2StreamChannel.Unsafe.close(...)
- Complete closePromise and promise that is given to close(...) in the correct order.
- Add unit test
Result:
Fixes [#7628] and [#7641]
Motivation:
If DefaultHttp2ConnectionEncoder process outbound operation it sometimes missed to call Http2LifecycleManager.onError(...) when the operation was executed asynchronously.
Modifications:
Make best effort to update flags but still ensure failures are propageted to Http2LifecycleManager.onError(...) in all cases.
Result:
More consistent handling of errors.
Motivation:
Pseudo headers are checked less frequently than normal headers, so
it is more efficient to check the latter first.
Modifications:
Swap the order of the check, and fix minor formatting
Result:
Possibly more efficient header checks
Motivation:
We can just implement the interfaces directly and so reduce object creation in DefaultHttp2RemoteFlowController.
Modifications:
Directly implement the interfaces.
Result:
Less object creation.
Motivation:
When part of a HTTP/2 StreamChannel the Http2StreamChannel.isOpen() / isActive() should report false within a call to a ChannelInboundHandlers channelInactive() method.
Modifications:
Fullfill promise before call fireChannelInactive()
Result:
Correctly update state / promise before notify handlers. Fixes [#7638]
Motivation:
With HTTP1, it's very easy to check if a header is present and has a
given value: you can simply invoke
io.netty.handler.codec.http.HttpHeaders#contains(java.lang.CharSequence, java.lang.CharSequence, boolean)
It is not possible to do the same with HTTP2. You have to get the list
of all headers (returned as String) and then iterate over it invoking
String#equals or String#equalsIgnoreCase
Modifications:
I've added io.netty.handler.codec.http2.Http2Headers#contains and
implemented it in DefaultHttp2Headers, EmptyHttp2Headers and ReadOnlyHttp2Headers.
Result:
You can use AsciiString constants to check if a header is present in a
consice and efficient manner.
Motivation:
Usually when using netty exceptions which happen for outbound operations should not be fired through the pipeline but only the ChannelPromise should be failed.
Modifications:
- Change Http2LifecycleManager.onError(...) to take also an boolean that indicate if the error was caused by an outbound operation
- Channel Http2ConnectionHandler.on*Error(...) methods to also take this boolean
- Change Http2FrameCodec to only fire exceptions through the pipeline if these are not outbound operations related
- Add unit test.
Result:
More consistent error handling when using Http2FrameCodec and Http2MultiplexCodec.
Motivation:
Http2MultiplexCodec swallows Http2PingFrames without releasing the payload, resulting in a memory leak.
Modification:
Send unhandled frames down the pipeline for consumption/disposal by another InboundChannelHandler.
Result:
Fixes#7607.
Motivation:
Usages of HttpResponseStatus may result in more object allocation then necessary due to not looking for cached objects and the AsciiString parsing method not being used due to CharSequence method being used instead.
Modifications:
- HttpResponseDecoder should attempt to get the HttpResponseStatus from cache instead of allocating a new object
- HttpResponseStatus#parseLine(CharSequence) should check if the type is AsciiString and redirect to the AsciiString parsing method which may not require an additional toString call
- HttpResponseStatus#parseLine(AsciiString) can be optimized and doesn't require and may not require object allocation
Result:
Less allocations when dealing with HttpResponseStatus.
Motivation:
When we cancel the flowcontrolled writes we did create a new StreamException for each write that was enqueued. Creating Exceptions is very expensive due of filling the stacktrace.
Modifications:
Only create the StreamException once and reuse the same for all the flowcontrolled writes (per stream).
Result:
Less expensive to cancel flowcontrolled writes.
Motivation:
Http2FrameCodec increases the initialWindowSize when the user attempts to increase the connection flow control window. The initialWindowSize should only be touched as a result of a SETTINGS frame, and otherwise may result in flow control getting out of sync with our peer.
Modifications:
- Http2FrameCodec shouldn't update the initialWindowSize when a WindowUpdateFrame is written on the connection channel
Result:
More correct WindowUpdate processing.
Motivation:
HPackDecoder works on entire header block, we shouldn't encounter
incomplete header fields. If we do we should treat it as
a decoding error and according to the specification:
A decoding error in a header block MUST be treated as
a connection error (Section 5.4.1) of type COMPRESSION_ERROR.
Modifications:
* Check final state in HpackDecoder once we've decoded all the data.
Result:
* Throw a connection error if we receive incomplete header fields
* H2spec 4.3 tests all passes
Motivation:
Http2FrameStream#CONNECTION_STREAM is required to identify the
connection stream. However this leads to inconsistent usage from a user
perspective. When a user creates a Http2Frame for a non-connection
stream, the Http2MultiplexCodec automatically sets the stream, and the
user is never exposed to the Http2FrameStream object. However when the
user writes a Http2Frame for a connection stream they are required to
set the Http2FrameStream object. We can remove the Http2FrameStream#CONNECTION_STREAM
and keep the Http2FrameStream object internal, and therefore consistent
between the connection and non-connection use cases.
Modifications:
- Remove Http2FrameStream#CONNECTION_STREAM
- Update Http2FrameCodec to handle Http2Frame#stream() which returns
null
Result:
More consistent usage on http2 parent channel and http2 child channel.
Motivation:
Http2FrameCodecTest#newOutboundStream has a timeout of 1 second and has been observed to timeout on CI servers.
Modifications:
- Increase the timeout to 5 seconds
Result:
Less false positive test failures on CI servers.
Motivation:
HpackDecoder#addHeader takes in the streamId as a parameter but no longer uses it.
Modifications:
- Remove the streamId parameter from HpackDecoder#addHeader
Result:
Less unused parameters in HpackDecoder.
Motivation:
According to the HTTP/2 Spec:
SETTINGS_MAX_HEADER_LIST_SIZE (0x6): This advisory setting informs a
peer of the maximum size of header list that the sender is
prepared to accept, in octets. The value is based on the
uncompressed size of header fields, including the length of the
name and value in octets plus an overhead of 32 octets for each
header field.
We were accounting for the 32 bytes when encoding in HpackEncoder,
but not when decoding in HPackDecoder.
Modifications:
- Add 32 bytes to the header list length for each entry when decoding
with HPackDecoder.
Result:
- We account for the 32 bytes overhead by header entry in HPackDecoder
Motiviation:
In our replace(...) methods we always used validation for the newly created headers while the original headers may not use validation at all.
Modifications:
- Only use validation if the original headers used validation as well.
- Ensure we create a copy of the headers in replace(...).
Result:
Fixes [#5226]
Motivation:
Currently the remote flow controller limits the maximum amount of pending data to Integer.MAX_VALUE. The overflow handling is also not very graceful in that it may lead to infinite loops, or otherwise no progress being made.
Modifications:
- StreamByteDistributor and RemoteFlowController should support pending bytes of type long.
Result:
Fixes https://github.com/netty/netty/issues/4283
Motivation:
http/2 counts header sizes somewhat inconsistently. Sometimes, headers
which are substantively less than the header list size will be measured
as longer than the header list size.
Modifications:
Keep better track of the nameLength of a given name, so that we don't
accidentally end up reusing a nameLength.
Result:
More consistent measurement of header list size.
Fixes#7511.
H2C upgrades should be ineligible for flow control
Motivation:
When the h2c upgrade request is too big, the Http2FrameCodec complains
it's too big for flow control reasons, even though it's ineligible for
flow control.
Modifications:
Specially mark upgrade streams and make Http2FrameCodec know not to try
to flow control on those streams.
Result:
Servers won't barf when they receive an upgrade request with a fat
payload.
[Fixes#7280]
Motivation:
Http2ConnectionHandler uses ctx.fireUserEvent to propagate the Http2ConnectionPrefaceAndSettingsFrameWrittenEvent through the pipeline. This will propagate the event to the next inbound handler in the pipeline. If the user extends Http2ConnectionHandler the Http2ConnectionPrefaceAndSettingsFrameWrittenEvent may be missed and initialization dependent upon this event will not be run.
Modifications:
- Http2ConnectionHandler should use userEventTriggered instead of ctx.fireUserEvent
Result:
Classes that extend Http2ConnectionHandler will see the Http2ConnectionPrefaceAndSettingsFrameWrittenEvent user event.
Motivation:
HttpConversionUtil#toHttp2Headers has special code to filter the TE header name. However this filtering code may result in adding the <TE, TRAILERS> tuple in scenarios that are not appropriate. For example if a value containing trailers is seen it will be added, but the value could not actually be equal to trailers. Also CSV values are not supported.
Modifications:
- Account for CSV header values
- Account for the value containing 'trailers' but not actually being equal to 'trailers'
Result:
More robust parsing of the TE header.
Modifications:
HttpConversionUtil#toLowercaseMap requires an intermediate List to be allocated. This can be avoided with the recently added value iterator methods.
Modifications:
- Use HttpHeaders#valueCharSequenceIterator instead of getAll
Result:
Less intermediate object allocation and copying.
Motivation:
DefaultHttp2FrameWriter#writeData allocates a DataFrameHeader for each write operation. DataFrameHeader maintains internal state and allocates multiple slices of a buffer which is a maximum of 30 bytes. This 30 byte buffer may not always be necessary and the additional slice operations can utilize retainedSlice to take advantage of pooled objects. We can also save computation and object allocations if there is no padding which is a common case in practice.
Modifications:
- Remove DataFrameHeader
- Add a fast path for padding == 0
Result:
Less object allocation in DefaultHttp2FrameWriter
Motivation:
AbstractByteBuf#readSlice relied upon the bounds checking of the slice operation in order to detect index out of bounds conditions. However the slice bounds checking operation allows for the slice to go beyond the writer index, and this is out of bounds for a read operation.
Modifications:
- AbstractByteBuf#readSlice and AbstractByteBuf#readRetainedSlice should ensure the desired amount of bytes are readable before taking a slice
Result:
No reading of undefined data in AbstractByteBuf#readSlice and AbstractByteBuf#readRetainedSlice.
Motivation:
Netty could handle "connection" or "te" headers more gently when
converting from http/1.1 to http/2 headers. Http/2 headers don't
support single-hop headers, so when we convert from http/1.1 to http/2,
we should drop all single-hop headers. This includes headers like
"transfer-encoding" and "connection", but also the headers that
"connection" points to, since "connection" can be used to designate
other headers as single-hop headers. For the "te" header, we can more
permissively convert it by just dropping non-conforming headers (ie
non-"trailers" headers) which is what we do for all other headers when
we convert.
Modifications:
Add a new blacklist to the http/1.1 to http/2 conversion, which is
constructed from the values of the "connection" header, and stop
throwing an exception when a "te" header is passed with a non-"trailers"
value. Instead, drop all values except for "trailers". Add unit tests
for "connection" and "te" headers when converting from http/1.1 to http/2.
Result:
This will improve the h2c upgrade request, and also conversions from
http/1.1 to http/2. This will simplify implementing spec-compliant
http/2 servers that want to share code between their http/1.1 and http/2
implementations.
[Fixes#7355]
Motivation:
HTTP/2 allows writes of 0 length data frames. However in some cases EMPTY_BUFFER is used instead of the actual buffer that was written. This may mask writes of released buffers or otherwise invalid buffer objects. It is also possible that if the buffer is invalid AbstractCoalescingBufferQueue will not release the aggregated buffer nor fail the associated promise.
Modifications:
- DefaultHttp2FrameCodec should take care to fail the promise, even if releasing the data throws
- AbstractCoalescingBufferQueue should release any aggregated data and fail the associated promise if something goes wrong during aggregation
Result:
More correct handling of invalid buffers in HTTP/2 code.
Motivation:
If a child channel's read is triggered outside the parent channel's read
loop then it is possible a WINDOW_UPDATE will be written, but not
flushed.
If a child channel's beginRead processes data from the inboundBuffer and
then readPending is set to false, which will result in data not being
delivered if in the parent's read loop and more data is attempted to be
delievered to that child channel.
Modifications:
- The child channel must force a flush if a frame is written as a result
of reading a frame, and this is not in the parent channel's read loop
- The child channel must allow a transition from dequeueing from
beginRead into the parent channel's read loop to deliver more data
Result:
The child channel flushes data when reading outside the parent's read
loop, and has frames delivered more reliably.
Motivation:
Http2StreamFrameToHttpObjectCodec was not properly encoding and
decoding 100-Continue HttpResponse/Http2SettingsFrame properly. It was
encoding 100-Continue FullHttpResponse as an Http2SettingFrame with
endStream=true, causing the child channel to terminate. It was not
decoding 100-Continue Http2SettingsFrame (endStream=false) as
FullHttpResponse. This should be fixed as it would cause http2 child
stream to prematurely close, and could cause HttpObjectAggregator to
fail if it's in the pipeline.
Modification:
- Fixed encode() to properly encode 100-Continue FullHttpResponse as
Http2SettingsFrame with endStream=false
- Reject 100-Continue HttpResponse that are NOT FullHttpResponse
- Fixed decode() to properly decode 100-Continue Http2SettingsFrame
(endStream=false) as a FullHttpResponse
- made Http2StreamFrameToHttpObjectCodec sharable so that it can b used
among child streams within the same Http2MultiplexCodec
Result:
Now Http2StreamFrameToHttpObjectCodec should be properly handling
100-Continue responses.
Motivation:
Previously client Http2ConnectionHandler trigger a user event
immediately when the HTTP/2 connection preface is sent. Any attempt to
immediately send a new request could cause the server to terminate the
connection, as it might not have received the SETTINGS frame from the
client. Per RFC7540 Section 3.5, the preface "MUST be followed by a
SETTINGS frame (Section 6.5), which MAY be empty."
(https://tools.ietf.org/html/rfc7540#section-3.5)
This event could be made more meaningful if it also indicates that the
initial client SETTINGS frame has been sent to signal that the channel
is ready to send new requests.
Modification:
- Renamed event to Http2ConnectionPrefaceAndSettingsFrameWrittenEvent.
- Modified Http2ConnectionHandler to trigger the user event only if it
is a client and it has sent both the preface and SETTINGS frame.
Result:
It is now safe to use the event as an indicator that the HTTP/2
connection is ready to send new requests.
Motivation:
A regression was introduced in 86e653e which had the effect that the writability was not updated for a Channel while queueing data in the SslHandler.
Modifications:
- Factor out code that will increment / decrement pending bytes and use it in AbstractCoalescingBufferQueue and PendingWriteQueue
- Add test-case
Result:
Channel writability changes are triggered again.
Motivation:
Objects of java.util.TreeMap or java.util.TreeSet will become
non-Serializable if instantiated with Comparators, which are not also
Serializable. This can result in unexpected and difficult-to-diagnose
bugs.
Modifications:
Implements Serializable for all classes, which implements Comparator.
Result:
Proper Comparators which will not force collections to
non-Serializable mode.
Motivation:
Even if it's a super micro-optimization (most JVM could optimize such
cases in runtime), in theory (and according to some perf tests) it
may help a bit. It also makes a code more clear and allows you to
access such methods in the test scope directly, without instance of
the class.
Modifications:
Add 'static' modifier for all methods, where it possible. Mostly in
test scope.
Result:
Cleaner code with proper 'static' modifiers.
Motivation:
Without a 'serialVersionUID' field, any change to a class will make
previously serialized versions unreadable.
Modifications:
Add missed 'serialVersionUID' field for all Serializable
classes.
Result:
Proper deserialization of previously serialized objects.
