Motivation:
`Http2FrameCodec#write(...)` has typo in comment.
`// In the event of manual SETTINGS ACK is is assumed the encoder will apply the earliest received but not`.
The typo is `is is`. However, it should be `it is`.
Modification:
Changed `is is` to `it is`.
Result:
Correct comment without typos.
Motivation:
`Http2DataFrame#isEndStream()` JavaDoc says `Returns {@code true} if the END_STREAM flag ist set.`. The typo is `ist` word. However, it should be `is`.
Modification:
Changed `ist` to `is`.
Result:
Better JavaDoc by fixing the typo.
Motivation:
`Http2HeadersFrame#isEndStream()` JavaDoc says `Returns {@code true} if the END_STREAM flag ist set.`. The typo is `ist` word. However, it should be `is`.
Modification:
Changed `ist` to `is`.
Result:
Better JavaDoc by fixing the typo.
Motivation:
`addHttp2ToHttpHeaders(int streamId, Http2Headers sourceHeaders, FullHttpMessage destinationMessage, boolean addToTrailer)`
should match
`addHttp2ToHttpHeaders(int streamId, Http2Headers inputHeaders, HttpHeaders outputHeaders, HttpVersion httpVersion, boolean isTrailer, boolean isRequest)`.
However, the `Http2Headers` variable name is different.
Modification:
Changed `sourceHeaders` to `inputHeaders`.
Result:
Variable and JavaDoc naming now correct.
Motivation:
Http2ToHttpHeaderTranslator is a private class but translateHeaders(Iterable<Entry<CharSequence, CharSequence>>) is public but it should be package-private.
Modification:
Removed public.
Result:
Correct access modifer.
Motivation:
Http2Headers has JavaDoc error which says Sets the {@link PseudoHeaderName#AUTHORITY} header or {@code null} if there is no such header however it should be Sets the {@link PseudoHeaderName#AUTHORITY} header in Http2Headers#authority(CharSequence) methods because it only sets CharSequence.
This is true for all setters in Http2Headers.
Modification:
Fixed all JavaDoc errors.
Result:
Better JavaDoc.
Motivation:
HTTP is a plaintext protocol which means that someone may be able
to eavesdrop the data. To prevent this, HTTPS should be used whenever
possible. However, maintaining using https:// in all URLs may be
difficult. The nohttp tool can help here. The tool scans all the files
in a repository and reports where http:// is used.
Modifications:
- Added nohttp (via checkstyle) into the build process.
- Suppressed findings for the websites
that don't support HTTPS or that are not reachable
Result:
- Prevent using HTTP in the future.
- Encourage users to use HTTPS when they follow the links they found in
the code.
Motivation:
junit deprecated Assert.assertThat(...)
Modifications:
Use MatcherAssert.assertThat(...) as replacement for deprecated method
Result:
Less deprecation warnings
Motivation:
We have a few classes in which we store and reuse static instances of various exceptions. When doing so it is important to also override fillInStacktrace() and so prevent the leak of the ClassLoader in the internal backtrace field.
Modifications:
- Add overrides of fillInStracktrace when needed
- Move ThrowableUtil usage in the static methods
Result:
Fixes https://github.com/netty/netty/pull/10686
Motivation:
We should use ObjectUtil for checking if Compression parameters are in range. This will reduce LOC and make code more readable.
Modification:
Used ObjectUtil
Result:
More readable code
Motivation:
We should simplify and remove useless bit operations to make code more efficient, faster, and easier to understand.
Modification:
Simplified and Removed Useless Bit Operations
Result:
Simpler Code.
Motivation:
`Http2MultiplexHandler` have to 2 empty lines at the end instead of 1.
Modification:
Removed 1 extra line.
Result:
Little better code style.
Motivation:
We can use ObjectUtil#checkPositive instead of manually checking maxContentLength. Also, there was a missing JavaDoc for Http2Exception,
Modification:
Used ObjectUtil#checkPositive for checking maxContentLength.
Added missing JavaDoc.
Result:
More readable code.
Motivation:
We wish to use Unsafe as little as possible, and Java 8 allows us
to take some short-cuts or play some tricks with generics,
for the purpose of working around having to declare all checked
exceptions. Ideally all checked exceptions would be declared, but
the code base is not ready for that yet.
Modification:
The call to UNSAFE.throwException has been removed, so when we need
that feature, we instead use the generic exception trick.
In may cases, Java 8 allows us to throw Throwable directly. This
happens in cases where no exception is declared to be thrown in a
scope.
Finally, some warnings have also been fixed, and some imports have
been reorganised and cleaned up while I was modifying the files
anyway.
Result:
We no longer use Unsafe for throwing any exceptions.
Motivation:
be able to modify Http2Settings of Http2ConnectionHandlerBuilder.
Modifications:
make initialSettings() of Http2ConnectionHandlerBuilder public.
Result:
public initialSettings() of Http2ConnectionHandlerBuilder allow Http2Settings modification.
Motivation:
Fix a TODO that was due since the "master" branch is baselined on at least Java 8.
Modification:
Remove our own copy of the Consumer interface and fix usage sites to use j.u.Consumer.
Also some cleanup.
Result:
Cleaner code.
Motivation
ByteBuf has an isAccessible method which was introduced as part of ref
counting optimizations but there are some places still doing
accessibility checks by accessing the volatile refCnt() directly.
Modifications
- Have PooledNonRetained(Duplicate|Sliced)ByteBuf#isAccessible() use
their refcount delegate's isAccessible() method
- Add static isAccessible(buf) and ensureAccessible(buf) methods to
ByteBufUtil
(since ByteBuf#isAccessible() is package-private)
- Adjust DefaultByteBufHolder and similar classes to use these methods
rather than access refCnt() directly
Result
- More efficient accessibility checks in more places
Motivation:
There should be a validation for the input arguments when constructing Http2FrameLogger
Modification:
Check that the provided arguments are not null
Result:
Proper validation when constructing Http2FrameLogger
Motivation:
We should include TLSv1.3 ciphers as well as recommented ciphers these days for HTTP/2. That is especially true as Java supports TLSv1.3 these days out of the box
Modifications:
- Add TLSv1.3 ciphers that are recommended by mozilla as was for HTTP/2
- Add unit test
Result:
Include TLSv1.3 ciphers as well
Motivation:
testStreamIsNotCreatedIfParentConnectionIsClosedConcurrently() made some assumptions about sequencing which may not be true all the time and racy.
Modifications:
Fix the testcase so its not racy anymore
Result:
Fix build failure on master branch
Motivation:
Setting a dependency on the connection is normal and permitted; streams
actually default to depending on the connection. Using a PRIORITY frame
with a dependency on the connection could reset a previous PRIORITY,
change the relative weight, or make all streams dependent on one stream.
The previous code was disallowing these usages as it considered
depending on the connection to be a validation failure.
Modifications:
Loosen validation check to also allow depending on the connection. Fix
error message when the validation check fails.
Result:
Setting a dependency on connection would be permitted. Fixes#10416
Motivation:
If a request to open a new h2 stream was made from outside of the
EventLoop it will be scheduled for future execution on the EventLoop.
However, during the time before the `open0` task will be executed the
parent channel may already be closed. As the result,
`Http2MultiplexHandler#newOutboundStream()` will throw an
`IllegalStateException` with the message that is hard to
interpret correctly for this use-case: "Http2FrameCodec not found. Has
the handler been added to a pipeline?".
Modifications:
- Check that the parent h2 `Channel` is still active before creating a
new stream when `open0` task is picked up by EventLoop;
Result:
Users see a correct `ClosedChannelException` in case the parent h2
`Channel` was closed concurrently with a request for a new stream.
Motivation:
`Http2StreamChannelBootstrap#open0` invokes
`Http2MultiplexHandler#newOutboundStream()` which may throw an
`IllegalStateException`. In this case, it will never complete
the passed promise.
Modifications:
- `try-catch` all invocations of `newOutboundStream()` and fail
promise in case of any exception;
Result:
New H2 stream promise always completes.
Motivation:
`DefaultHttp2FrameStream.stream` is not used outside of its class and
therefore can be private.
Modifications:
- Make `DefaultHttp2FrameStream.stream` private;
Result:
Correct visibility scoping for `DefaultHttp2FrameStream.stream`.
Motivation:
From the recent benchmark using gRPC-Java based on Netty's HTTP2, it appears that it prefers `ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256` over `ECDHE_ECDSA_WITH_AES_128_GCM_SHA256` since it uses the Netty HTTPS Cipher list as is. Both are considered safe but `ECDHE_ECDSA_WITH_AES_128_GCM_SHA256` has a good chance to get more optimized implementation. (e.g. AES-NI) When running both on GCP Intel Haswell VM, `TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256` spent 3x CPU time than `TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256`. (Note that this VM supports AES-NI)
From the cipher suites listed on `Intermediate compatibility (recommended)` of [Security/Server Side TLS](https://wiki.mozilla.org/Security/Server_Side_TLS#Modern_compatibility), they have a cipher preference which is aligned with this PR.
```
0x13,0x01 - TLS_AES_128_GCM_SHA256 TLSv1.3 Kx=any Au=any Enc=AESGCM(128) Mac=AEAD
0x13,0x02 - TLS_AES_256_GCM_SHA384 TLSv1.3 Kx=any Au=any Enc=AESGCM(256) Mac=AEAD
0x13,0x03 - TLS_CHACHA20_POLY1305_SHA256 TLSv1.3 Kx=any Au=any Enc=CHACHA20/POLY1305(256) Mac=AEAD
0xC0,0x2B - ECDHE-ECDSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(128) Mac=AEAD
0xC0,0x2F - ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(128) Mac=AEAD
0xC0,0x2C - ECDHE-ECDSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(256) Mac=AEAD
0xC0,0x30 - ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(256) Mac=AEAD
0xCC,0xA9 - ECDHE-ECDSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH Au=ECDSA Enc=CHACHA20/POLY1305(256) Mac=AEAD
0xCC,0xA8 - ECDHE-RSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH Au=RSA Enc=CHACHA20/POLY1305(256) Mac=AEAD
0x00,0x9E - DHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(128) Mac=AEAD
0x00,0x9F - DHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(256) Mac=AEAD
```
Modification:
Moving up `AES_128_GCM_SHA256` in the CIPHERS of HTTPS so that it gets priority.
Result:
When connecting to the server supporting both `ECDHE_ECDSA_WITH_AES_128_GCM_SHA256` and `ECDSA_WITH_CHACHA20_POLY1305_SHA256` and respecting the client priority of cipher suites, it will be able to save significant cpu time when running it on machines with AES-NI support.
Motivation:
The result of `header.size()` is already cached in `headerSize`. There is no need to call it again actually.
Modification:
Replace the second `header.size()` with `headerSize` directly.
Result:
Improve performance slightly.
Motivation:
`getEntry(...)` may throw an IndexOutOfBoundsException without any error messages.
Modification:
Add detailed error message corresponding to the IndexOutOfBoundsException while calling `getEntry(...)` in HpackDynamicTable.java.
Result:
Easier to debug
Motivation:
`HpackDynamicTable` needs some test cases to ensure bug-free.
Modification:
Add unit test for `HpackDynamicTable`.
Result:
Improve test coverage slightly.
Motivation:
After searching the whole netty project, I found that the private method `translateHeader(...)` with empty body is never used actually. So I think it could be safely removed.
Modification:
Just remove this unused method.
Result:
Clean up the code.
Motivation:
`io.netty.handler.codec.http2.Http2Stream.State` is never used in DefaultHttp2LocalFlowController.java, and `io.netty.handler.codec.http2.HpackUtil.equalsConstantTime` is never used in HpackStaticTable.java.
Modification:
Just remove these unused imports.
Result:
Make imports cleaner.
Motivation:
`io.netty.handler.codec.http2.Http2CodecUtil.DEFAULT_PRIORITY_WEIGHT` is never used in DefaultHttp2ConnectionEncoder.java.
Modification:
Just remove this unused import.
Result:
Make the DefaultHttp2ConnectionEncoder.java's imports clean.
Motivation:
Http2ConnectionHandler may call ctx.close(...) with the same promise instance multiple times if the timeout for gracefulShutdown elapse and the listener itself is notified. This can cause problems as other handlers in the pipeline may queue these promises and try to notify these later via setSuccess() or setFailure(...) which will then throw an IllegalStateException if the promise was notified already
Modification:
- Add boolean flag to ensure doClose() will only try to call ctx.close(...) one time
Result:
Don't call ctx.close(...) with the same promise multiple times when gradefulShutdown timeout elapses.
Motivation:
Http2StreamChannelId is Serializable. A test case is needed to ensure that it works.
Modification:
Add a test case about serialization.
Result:
Improve test coverage slightly.
Motivation:
Under certain read patters the AbstractHttp2StreamChannel can fail to
flush, resulting in flow window starvation.
Modifications:
- Ensure we flush if we exit the `doBeginRead()` method.
- Account for the Http2FrameCodec always synchronously finishing writes
of window update frames.
Result:
Fixes#10072
Motivation:
At the moment the next / prev references are not set to "null" in the DefaultChannelHandlerContext once the ChannelHandler is removed. This is bad as it basically let users still use the ChannelHandlerContext of a ChannelHandler after it is removed and may produce very suprising behaviour.
Modifications:
- Fail if someone tries to use the ChannelHandlerContext once the ChannelHandler was removed (for outbound operations fail the promise, for inbound fire the error through the ChannelPipeline)
- Fix some handlers to ensure we not use the ChannelHandlerContext after the handler was removed
- Adjust DefaultChannelPipeline / DefaultChannelHandlerContext to fixes races with removal / replacement of handlers
Result:
Cleanup behaviour and make it more predictable for pipeline modifications
Motivation:
Even if it was stored in the string constant pool, I thought it was safe to compare it through the Equals() method.
Modification:
So, I changed "==" comparison to equals() comparison
Result:
It has become safer to compare String values with different references and with the same values.
Motivation:
We need to carefully manage flushes to ensure we not discard these by mistake due wrongly implemented consolidation of flushes.
Modifications:
- Ensure we reset flag before we actually call flush0(...)
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/10015
Motivation:
Users of the DefaultHttp2ConnectionDecodcer are notified of inbound GoAwayFrames
after the connection has already closed any ignored streams, potentially
losing the signal that some streams may have been ignored by the peer and
are thus retryable.
Modifications:
Reorder the notifications of the frame and connection listeners to
propagate the frame first, giving the frame listeners the opportunity to
clean up ignored streams in their own way.
Result:
Fixes#9986
Motivation:
ClearTextHttp2ServerUpgradeHandler is currently more complex then needed. We can simplify it by directly implement the prior-knowledge logic as part of the handler.
Modifications:
Merge inner PriorKnowledgeHandler logic into ClearTextHttp2ServerUpgradeHandler by extending ByteToMessageDecoder directly
Result:
Cleaner code and less pipeline operations
Motivation:
https://github.com/netty/netty/pull/9848 changed how we handled ChannelOptions internally to use a ConcurrentHashMap. This unfortunally had the side-effect that the ordering may be affected and not stable anymore. Here the problem is that sometimes we do validation based on two different ChannelOptions (for example we validate high and low watermarks against each other). Thus even if the user specified the options in the same order we may fail to configure them.
Modifications:
- Use again a LinkedHashMap to preserve order
Result:
Apply ChannelOptions in correct and expected order
Motivation:
In next major version of netty users should use ChannelHandler everywhere. We should ensure we do the same
Modifications:
Replace usage of deprecated classes / interfaces with ChannelHandler
Result:
Use non-deprecated code
Motivation:
ByteToMessageDecoder requires using an intermediate List to put results into. This intermediate list adds overhead (memory/CPU) which grows as the number of objects increases. This overhead can be avoided by directly propagating events through the ChannelPipeline via ctx.fireChannelRead(...). This also makes the semantics more clear and allows us to keep track if we need to call ctx.read() in all cases.
Modifications:
- Remove List from the method signature of ByteToMessageDecoder.decode(...) and decodeLast(...)
- Adjust all sub-classes
- Adjust unit tests
- Fix javadocs.
Result:
Adjust ByteToMessageDecoder as noted in https://github.com/netty/netty/issues/8525.
# Motivation:
`DefaultByteBufHolder.equals()` considers another object equal if it's an instance of `ByteBufferHolder` and if the contents of two objects are equal. However, the behavior of `equals` method is not a part of the `ByteBufHolder` contract so `DefaultByteBufHolder`'s version may be causing violation of the symmetric property if other classes have different logic.
There are already a few classes that are affected by this: `DefaultHttp2GoAwayFrame`, `DefaultHttp2UnknownFrame`, and `SctpMessage` are all overriding `equals` method breaking the symmetric property.
Another effect of this behavior is that all instances with empty data are considered equal. That may not be desireable in the situations when instances are created for predefined constants, e.g. `FullBulkStringRedisMessage.NULL_INSTANCE` and `FullBulkStringRedisMessage.EMPTY_INSTANCE` in `codec-redis`.
# Modification:
Make `DefaultByteBufHolder.equals()` implementation only work for the objects of the same class.
# Result:
- The symmetric property of the `equals` method is restored for the classes in question.
- Instances of different classes are not considered equal even if the content of the data they hold are the same.
Motivation:
We should use Objects.requireNonNull(...) as we require java8
Modifications:
Replace ObjectUtil.checkNonNull(...) with Objects.requireNonNull(...)
Result:
Code cleanup
Motivation:
The current implementation delegates to writeHeaders(ChannelHandlerContext ctx, int streamId, Http2Headers headers, int streamDependency, short weight, boolean exclusive, int padding, boolean endStream, ChannelPromise promise) that will send an header frame with the priority flag set and the default priority values even if the user didnt want too.
Modifications:
- Change DefaultHttp2ConnectionEncoder to call the correct Http2FrameWriter method depending on if the user wants to use priorities or not
- Adjust tests
Result:
Fixes https://github.com/netty/netty/issues/9842
Motivation:
97361fa2c8 replace synchronized with ConcurrentHashMap in *Bootstrap classes but missed to do the same for the Http2 variant.
Modifications:
- Use ConcurrentHashMap
- Simplify code in *Bootstrap classes
Result:
Less contention
Motivation:
We use the onStreamClosed(...) callback to return unconsumed bytes back to the window of the connection when needed. When this happens we will write a window update frame but not automatically call ctx.flush(). As the user has no insight into this it could in the worst case result in a "deadlock" as the frame is never written out ot the socket.
Modifications:
- If onStreamClosed(...) produces a window update frame call ctx.flush()
- Add unit test
Result:
No stales possible due unflushed window update frames produced by onStreamClosed(...) when not all bytes were consumed before the stream was closed
Motivation:
We can make use of EmbeddedChannel.finishAndReleaseAll() and so remove some code
Modifications:
Use finishAndReleaseAll()
Result:
Less code to maintain
Motivation:
At the moment we send a window update frame for the connection + stream when a stream is closed and there are unconsumed bytes left. While we need to do this for the connection it makes no sense to write a window update frame for the stream itself as it is already closed
Modifications:
- Don't write the window update frame for the stream when the stream is closed
- Add unit test
Result:
Don't write the window frame for closed streams
Motivation:
Http2ConnectionHandler tries to guard against sending multiple RST frames for the same stream. Unfortunally the code is not 100 % correct as it only updates the state after it calls write. This may lead to the situation of have an extra RST frame slip through if the second write for the RST frame is done from a listener that is attached to the promise.
Modifications:
- Update state before calling write
- Add unit test
Result:
Only ever send one RST frame per stream
Motivation:
There is an intrinsic race between a local session resetting a stream
and the peer no longer sending any frames. This can result in the
session receiving frames for a stream that the local peer no longer
tracks. This results in a StreamException being thrown which triggers a
RST_STREAM frame, which is a good thing, but also logging at level WARN,
which is noisy for an expected and benign condition.
Modification:
Change the log level to DEBUG when logging stream errors with code
STREAM_CLOSED. All others are more interesting and will continue to be
logged at level WARN.
Additionally, it was found that DATA frames for streams that could not
have existed only resulted in a StreamException when the spec is clear
that such a situation should be fatal to the connection, resulting in a
GOAWAY(PROTOCOL_ERROR).
Fixes#8025.
Motivation:
To avoid regression regarding connection-specific headers[1], we should add a test.
[1] https://tools.ietf.org/html/rfc7540#section-8.1.2.2
Modification:
Add test that checks the following headers are removed.
- Connection
- Host
- Keep-Alive
- Proxy-Connection
- Transfer-Encoding
- Upgrade
Result:
There's no functional change.
Motivation:
Padding was removed from CONTINUATION frame in http2-spec, as showed in [PR](https://github.com/http2/http2-spec/pull/510). We should follow it.
Modifications:
- Remove padding when writing CONTINUATION frame in DefaultHttp2FrameWriter
- Add a unit test for writing large header with padding
Result:
More spec-compliant
Motivation
Per javadoc in 4.1.x SimpleChannelInboundHandler:
"Please keep in mind that channelRead0(ChannelHandlerContext, I) will be
renamed to messageReceived(ChannelHandlerContext, I) in 5.0."
Modifications
Rename aforementioned method and all references/overrides.
Result
Method is renamed.
Motivation:
The javadocs of Http2Headers.method(...) are incorrect, we should fix these.
Modifications:
Correct javadocs
Result:
Fixes https://github.com/netty/netty/issues/8068.
Motivation:
Netty HTTP/2 implementation is not 100% compliant to the spec. This
commit improves the compliance regarding headers validation,
in particular pseudo-headers and connection ones.
According to the spec:
All HTTP/2 requests MUST include exactly one valid value for the
":method", ":scheme", and ":path" pseudo-header fields, unless it is
a CONNECT request (Section 8.3). An HTTP request that omits
mandatory pseudo-header fields is malformed (Section 8.1.2.6).
Modifications:
- Introduce Http2HeadersValidator class capable of validating HTTP/2
headers
- Invoke validation from DefaultHttp2ConnectionDecoder#onHeadersRead
- Modify tests to use valid headers when required
- Modify HttpConversionUtil#toHttp2Headers to not add :scheme and
:path header on CONNECT method in order to conform to the spec
Result:
- Initial requests without :method, :path, :scheme will fail
- Initial requests with multiple values for :method, :path, :scheme
will fail
- Initial requests with an empty :path fail
- Requests with connection-specific header field will fail
- Requests with TE header different than "trailers" will fail
-
- Fixes 8.1.2.2 tests from h2spec #5761
- Fixes 8.1.2.3 tests from h2spec #5761
Motivation:
Constant time comparison functions are used to compare HTTP/2 header
values, even if they are not sensitive.
Modification:
After checking for sensitivity, use fast comparison.
Result: Faster HPACK table reads/writes
Motivation:
We may fail to update the flow-controller and in this case need to notify the stream channel and close it.
Modifications:
Attach a future to the write of the update frame and in case of a failure propagate it to the channel and close it
Result:
Fixes https://github.com/netty/netty/issues/9663
Motivation:
bbc34d0eda introduced correct handling of "in process" setup of streams but there is some room for improvements. Often the writeHeaders(...) is completed directly which means there is not need to create the extra listener object.
Modifications:
- Only create the listener if we really need too.
Result:
Less GC
Motivation:
In https://github.com/netty/netty/issues/8692, `Http2FrameCodec` was
updated to keep track of all "being initialized" streams, allocating
memory before initialization begins, and releasing memory after
initialization completes successfully.
In some instances where stream initialization fails (e.g. because this
connection has received a GOAWAY frame), this memory is never released.
Modifications:
This change updates the `Http2FrameCodec` to use a separate promise
for monitoring the success of sending HTTP2 headers. When sending of
headers fails, we now make sure to release memory allocated for stream
initialization.
Result:
After this change, failures in writing HTTP2 Headers (e.g. because this
connection has received a GOAWAY frame) will no longer leak memory.
Motivation:
Http2MultiplexCodec extends Http2FrameCodec extends Http2ConnectionHandler. It appears Http2MultiplexCodec overrode the channelWritabilityChanged method, which prevented the flow controller from becoming active. In the case the parent channel becomes unwritable, and then later becomes writable, it needs to indicate that the child channels can still write data. This is slightly confusing, because the child channels may still themselves be unwritable, but should still drain their data to the parent channel.
Modification:
Still propagate writability changes to the HTTP/2 flow controller
Result:
Fixes https://github.com/netty/netty/issues/9636
Motivation:
Native image compilation is failing without extra flags:
```
Warning: Aborting stand-alone image build. No instances of io.netty.buffer.UnpooledHeapByteBuf are allowed in the image heap as this class should be initialized at image runtime. Object has been initialized by the io.netty.handler.codec.http2.Http2ConnectionHandler class initializer with a trace:
at io.netty.buffer.Unpooled.wrappedBuffer(Unpooled.java:157)
at io.netty.handler.codec.http2.Http2ConnectionHandler.<clinit>(Http2ConnectionHandler.java:74)
. To fix the issue mark io.netty.buffer.UnpooledHeapByteBuf for build-time initialization with --initialize-at-build-time=io.netty.buffer.UnpooledHeapByteBuf or use the the information from the trace to find the culprit and --initialize-at-run-time=<culprit> to prevent its instantiation.
Detailed message:
Trace: object io.netty.buffer.ReadOnlyByteBuf
object io.netty.buffer.UnreleasableByteBuf
method io.netty.handler.codec.http2.Http2ConnectionHandler.access$500()
Call path from entry point to io.netty.handler.codec.http2.Http2ConnectionHandler.access$500():
at io.netty.handler.codec.http2.Http2ConnectionHandler.access$500(Http2ConnectionHandler.java:66)
at io.netty.handler.codec.http2.Http2ConnectionHandler$PrefaceDecoder.readClientPrefaceString(Http2ConnectionHandler.java:299)
at io.netty.handler.codec.http2.Http2ConnectionHandler$PrefaceDecoder.decode(Http2ConnectionHandler.java:239)
at io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:438)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:505)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:444)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:283)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
at io.netty.channel.AbstractChannelHandlerContext.access$600(AbstractChannelHandlerContext.java:56)
at io.netty.channel.AbstractChannelHandlerContext$7.run(AbstractChannelHandlerContext.java:365)
at com.oracle.svm.core.jdk.RuntimeSupport.executeHooks(RuntimeSupport.java:144)
at com.oracle.svm.core.jdk.RuntimeSupport.executeStartupHooks(RuntimeSupport.java:89)
at com.oracle.svm.core.JavaMainWrapper.runCore(JavaMainWrapper.java:143)
at com.oracle.svm.core.JavaMainWrapper.run(JavaMainWrapper.java:186)
at com.oracle.svm.core.code.IsolateEnterStub.JavaMainWrapper_run_5087f5482cc9a6abc971913ece43acb471d2631b(generated:0)
```
Modification:
Add `io.netty.handler.codec.http2.Http2ConnectionHandler` for runtime compilation, as the buffer library's `io.netty.buffer.UnpooledHeapByteBuf` is also marked for runtime.
Result:
Native image compilation works again.
Motivation:
`DefaultHttp2UnknownFrame#equals` may produce NPE due to
incorrect comparison of `stream` field.
Modification:
- Fix the `stream` field compare.
- Cleanup usage of class fields: use direct access instead of getters
(because the class is final).
Result:
No NPE in `equals` method.
Motivation:
Classes `AbstractHttp2StreamChannel.Http2StreamChannelConfig`
and `DnsNameResolver.AddressedEnvelopeAdapter` may be static:
it doesn't reference its enclosing instance.
Modification:
Add `static` modifier.
Result:
Prevents a possible memory leak and uses less memory per class instance.
Motivation:
At the moment we use Unpooled.buffer(...) in InboundHttp2ToHttpAdapter when we need to do a copy of the message. We should better use the configured ByteBufAllocator for the Channel
Modifications:
Change internal interface to also take the ByteBufAllocator as argument and use it when we need to allocate a ByteBuf.
Result:
Use the "correct" ByteBufAllocator in InboundHttp2ToHttpAdapter in all cases
Motivation:
At the moment we set release to false before we call writeData(...). This could let to the sitatuation that we will miss to release the message if writeData(...) throws. We should set release to false after we called writeData(...) to ensure the ownership of the buffer is correctly transferred.
Modifications:
- Set release to false after writeData(...) was successfully called only
Result:
No possibility for a buffer leak
Motivation:
We did miss to take Http2FrameCodecBuilder.isValidateHeaders() into account when a Http2FrameWriter was set on the builder and always assumed validation should be enabled.
Modifications:
Remove hardcode value and use configured value
Result:
Http2FrameCodecBuilder.isValidateHeaders() is respected in all cases
Motivation:
Error: Class that is marked for delaying initialization to run time got initialized during image building: io.netty.handler.codec.http2.Http2CodecUtil. Try marking this class for build-time initialization with --initialize-at-build-time=io.netty.handler.codec.http2.Http2CodecUtil
Error: Use -H:+ReportExceptionStackTraces to print stacktrace of underlying exception
Error: Image build request failed with exit status 1
Modification:
After debugging, it seems the culprit is io.netty.handler.codec.http2.Http2ClientUpgradeCodec, which also needs runtime initialisation.
Result:
Fixes #micronaut-projects/micronaut-grpc#8
Motiviation:
EmbeddedChannel currently is quite differently in terms of semantics to other Channel implementations. We should better change it to be more closely aligned and so have the testing code be more robust.
Modifications:
- Change EmbeddedEventLoop.inEventLoop() to only return true if we currenlty run pending / scheduled tasks
- Change EmbeddedEventLoop.execute(...) to automatically process pending tasks if not already doing so
- Adjust a few tests for the new semantics (which is closer to other Channel implementations)
Result:
EmbeddedChannel works more like other Channel implementations
Motivation:
At the moment it is quite easy to hit reentrance issues when you have multiple handlers in the pipeline and each of the handlers does not correctly protect against these. To make it easier for the user we should try to protect from these. The issue is usually if and inbound event will trigger and outbound event and this outbound event then against triggeres an inbound event. This may result in having methods in a ChannelHandler re-enter some method and so state can be corrupted or messages be re-ordered.
Modifications:
- Keep track of inbound / outbound operations in DefaultChannelHandlerContext and if reentrancy is detected break it by scheduling the action on the EventLoop. This will then be picked up once the method returns and so the reentrancy is broken up.
- Adjust tests which made strange assumptions about execution order
Result:
No more reentrancy of handlers possible.
Motivation:
Right now you can cancel the Future returned by
`Http2StreamChannelBootstrap.open()` and that will race with the
registration of the stream channel with the event loop, potentially
culminating in an `IllegalStateException` and potential resource leak.
Modification:
Ensure that the returned promise is uncancellable.
Result:
Should no longer see `IllegalStateException`s.
Motivation:
In the release (4.1.37) we introduced Http2MultiplexHandler as a
replacement of Http2MultiplexCodec. This did split the frame parsing from
the multiplexing to allow a more flexible way to handle frames and to make
the code cleaner. Unfortunally we did miss to special handle this in
Http2ClientUpgradeCodec and so did not correctly add Http2MultiplexHandler
to the pipeline before calling Http2FrameCodec.onHttpClientUpgrade(...).
This did lead to the situation that we did not correctly receive the event
on the Http2MultiplexHandler and so did not correctly created the
Http2StreamChannel for the upgrade stream. Because of this we ended up
with an NPE if a frame was dispatched to the upgrade stream later on.
Modifications:
- Correctly add Http2MultiplexHandler to the pipeline before calling Http2FrameCodec.onHttpClientUpgrade(...)
Result:
Fixes#9495.
Motivation:
Some of the links in javadoc point to the obsolete drafts of HTTP/2
specifications. We should point them to the latest RFC 7540 or 7541.
Modifications:
Update links from `draft-ietf-httpbis-*` to the `rfc7540` and `rfc7541`.
Result:
Correct links in javadoc.
Motivation:
We should better update the flow-controller on Channel.read() to reduce overhead and memory overhead.
See https://github.com/netty/netty/pull/9390#issuecomment-513008269
Modifications:
Move updateLocalWindowIfNeeded() to doBeginRead()
Result:
Reduce memory overhead
Motivation:
As we decorate the Http2FrameListener under the covers we should ensure the user can still access the original Http2FrameListener.
Modifications:
- Unwrap the Http2FrameListener in frameListener()
- Add unit test
Result:
Less suprises for users.
Motivation:
We recently introduced Http2ControlFrameLimitEncoderTest which did not correctly notify the goAway promises and so leaked buffers.
Modifications:
Correctly notify all promises and so release the debug data.
Result:
Fixes leak in HTTP2 test
Motivation:
It is possible for a remote peer to flood the server / client with empty DATA frames (without end_of_stream flag) set and so cause high CPU usage without the possibility to ever hit a limit. We need to guard against this.
See CVE-2019-9518
Modifications:
- Add a new config option to AbstractHttp2ConnectionBuilder and sub-classes which allows to set the max number of consecutive empty DATA frames (without end_of_stream flag). After this limit is hit we will close the connection. A limit of 10 is used by default.
- Add unit tests
Result:
Guards against CVE-2019-9518
Motivation:
Due how http2 spec is defined it is possible by a remote peer to flood us with frames that will trigger control frames as response, the problem here is that the remote peer can also just stop reading these (while still produce more of these) and so may drive us to the pointer where we either run out of memory or burn all CPU. To protect against this we need to implement some kind of limit that will tear down connections that cause the above mentioned situation.
See CVE-2019-9512 / CVE-2019-9514 / CVE-2019-9515
Modifications:
- Add Http2ControlFrameLimitEncoder which limits the number of queued control frames that were caused because of the remote peer.
- Allow to insert ths Http2ControlFrameLimitEncoder by setting AbstractHttp2ConnectionBuilder.encoderEnforceMaxQueuedControlFrames(...) to a number higher then 0. The default is 10000 which provides some protection by default but will hopefully not cause too many false-positives.
- Add unit tests
Result:
Protect against DDOS due control frames. Fixes CVE-2019-9512 / CVE-2019-9514 / CVE-2019-9515 .
Motivation:
We should delay the firing of the Http2ConnectionPrefaceAndSettingsFrameWrittenEvent by one EventLoop tick when using the Http2FrameCodec to ensure all handlers are added to the pipeline before the event is passed through it.
This is needed to workaround a race that could happen when the preface is send in handlerAdded(...) but a later handler wants to act on the event.
Modifications:
Offload firing of the event to the EventExecutor.
Result:
Fixes https://github.com/netty/netty/issues/9432.
Motivation:
306299323c introduced some code change to move the responsibility of creating the stream for the upgrade to Http2FrameCodec. Unfortunaly this lead to the situation of having newStream().setStreamAndProperty(...) be called twice. Because of this we only ever saw the channelActive(...) on Http2StreamChannel but no other events as the mapping was replaced on the second newStream().setStreamAndProperty(...) call.
Beside this we also did not use the correct handler for the upgrade stream in some cases
Modifications:
- Just remove the Http2FrameCodec.onHttpClientUpgrade() method and so let the base class handle all of it. The stream is created correctly as part of the ConnectionListener implementation of Http2FrameCodec already.
- Consolidate logic of creating stream channels
- Adjust unit test to capture the bug
Result:
Fixes https://github.com/netty/netty/issues/9395
Motivation:
When using the HTTP/2 multiplex implementation we need to ensure we correctly drain the buffered inbound data even if the RecvByteBufallocator.Handle tells us to stop reading in between.
Modifications:
Correctly loop through the buffered inbound data until the user does stop to request from it.
Result:
Fixes https://github.com/netty/netty/issues/9387.
Co-authored-by: Bryce Anderson <banderson@twitter.com>
Motivation:
We can easily reuse the Http2FrameStreamEvent instances and so reduce GC pressure as there may be multiple events per streams over the life-time.
Modifications:
Reuse instances
Result:
Less allocations
Motivation:
At the moment we lookup the ChannelHandlerContext used in Http2StreamChannelBootstrap each time the open(...) method is invoked. This is not needed and we can just cache it for later usage.
Modifications:
Cache ChannelHandlerContext in volatile field.
Result:
Speed up open(...) method implementation when called multiple times
Motivation:
If a read triggers a AbstractHttp2StreamChannel to close we can
get an NPE in the read loop.
Modifications:
Make sure that the inboundBuffer isn't null before attempting to
continue the loop.
Result:
No NPE.
Fixes#9337
Motivation:
The Http2FrameCodec should be responsible to create the upgrade stream.
Modifications:
Move code to create stream to Http2FrameCodec
Result:
More correct responsibility
Motivation:
Mark Http2StreamChannelBootstrap.open0(...) as deprecated as the user should not use it. It was marked as public by mistake.
Modifications:
Add deprecation warning.
Result:
User will be aware the method should not be used directly.
Motivation:
There are situations where the user may want to be more flexible when to send the PING acks for various reasons or be able to attach a listener to the future that is used for the ping ack. To be able to do so we should allow to manage the acks manually.
Modifications:
- Add constructor to DefaultHttp2ConnectionDecoder that allows to disable the automatically sending of ping acks (default is to send automatically to not break users)
- Add methods to AbstractHttp2ConnectionHandlerBuilder (and sub-classes) to either enable ot disable auto acks for pings
- Make DefaultHttp2PingFrame constructor public that allows to write acks.
- Add unit test
Result:
More flexible way of handling acks.
Motivation:
Netty homepage(netty.io) serves both "http" and "https".
It's recommended to use https than http.
Modification:
I changed from "http://netty.io" to "https://netty.io"
Result:
No effects.
Motivation:
Http2ConnectionHandler (and sub-classes) allow to configure a graceful shutdown timeout but only apply it if there is at least one active stream. We should always apply the timeout. This is also true when we try to send a GO_AWAY and close the connection because of an connection error.
Modifications:
- Always apply the timeout if one is configured
- Add unit test
Result:
Always respect gracefulShutdownTimeoutMillis
Motivation:
b3dba317d7 introduced the concept of Http2SettingsReceivedConsumer but did not correctly inplement DecoratingHttp2ConnectionEncoder.consumeRemoteSettings(...).
Modifications:
- Add missing `else` around the throws
- Add unit tests
Result:
Correctly implement DecoratingHttp2ConnectionEncoder.consumeRemoteSettings(...)
Motivation
The nice change made by @carl-mastrangelo in #9307 for lookup-table
based HPACK Huffman decoding can be simplified a little to remove the
separate flags field and eliminate some intermediate operations.
Modification
Simplify HpackHuffmanDecoder::decode logic including de-dup of the
per-nibble part.
Result
Less code, possibly better performance though not noticeable in a quick
benchmark.
