Motivation:
Alignment handling was broken, and basically turned into a fixed offset into each allocation address regardless of its initial value, instead of ensuring that the allocated address is either aligned or bumped to the nearest alignment offset.
The brokenness of the alignment handling extended so far, that overlapping ByteBuf instances could even be created, as was seen in #11101.
Modification:
Instead of fixing the per-allocation pointer bump, we now ensure that 1) the minimum page size is a whole multiple of the alignment, and 2) the reference memory for each chunk is bumped to the nearest aligned address, and finally 3) ensured that the reservations are whole multiples of the alignment, thus ensuring that the next allocation automatically occurs from an aligned address.
Incidentally, (3) above comes for free because the reservations are in whole pages, and in (1) we ensured that pages are sized in whole multiples of the alignment.
In order to ensure that the memory for a chunk is aligned, we introduce some new PlatformDependent infrastructure.
The PlatformDependent.alignDirectBuffer will produce a slice of the given buffer, and the slice will have an address that is aligned.
This method is plainly available on ByteBuffer in Java 9 onwards, but for pre-9 we have to use Unsafe, which means it can fail and might not be available on all platforms.
Attempts to create a PooledByteBufAllocator that uses alignment, when this is not supported, will throw an exception.
Luckily, I think use of aligned allocations are rare.
Result:
Aligned pooled byte bufs now work correctly, and never have any overlap.
Fixes#11101
Motivation
A GOAWAY frame (or any other HTTP/2 frame) should not be sent before the
connection preface. Clients that immediately close the channel may
currently attempt to send a GOAWAY frame before the connection preface,
resulting in servers receiving a seemingly-corrupt connection preface.
Modifications
* Ensure that the preface has been sent before attempting to
automatically send a GOAWAY frame as part of channel shutdown logic
* Add unit test that only passes with new behavior
Result
Fixes https://github.com/netty/netty/issues/11026
Co-authored-by: Bennett Lynch <Bennett-Lynch@users.noreply.github.com>
Motivation:
If compression is enabled and the HttpResponse also
implements HttpContent (but not LastHttpContent) then
the buffer will be freed to eagerly.
Modification:
I retain the buffer the same way that is done for the LastHttpContent case.
Note that there is another suspicious looking call a few lines above (if beginEncode returns null). I am not sure if this should also be retained.
Result:
Fixes#11092
Motivation:
netty-build is now called netty-build-common
Modifications:
Rename netty-build to netty-build-common
Result:
Be able to compile branch again
Motivation:
Components in a composite buffer can "go missing" if the composite is a slice of another composite and the parent has changed its layout.
Modification:
Where we would previously have thrown a NullPointerException, we now have a null-check for the component, and we instead throw an IllegalStateException with a more descriptive message.
Result:
It's now a bit easier to understand what is going on in these situations.
Fixes#10908
Motivation:
Newer versions of dawidd6/action-download-artifact changed the default
workflow_conclusion from "completed" to "completed, success" which can
result in download failures if the associated job fails, which is
expected when tests fail.
Modifications:
- Explicitly set the workflow_conclusion to "completed"
Result:
Test failures which result in build failures will still download test
data and generate reports after updating
dawidd6/action-download-artifact.
... number of bytes when using DatagramChannels
Motivation:
In our FixedRecvByteBufAllocator we dont continue to read if the number of bytes is less then what was configured. This is correct when using it for TCP but not when using it for UDP. When using UDP the number of bytes is the maximum of what we want to support but we often end up processing smaller datagrams in general. Because of this we should use contineReading(UncheckedBooleanSupplier) to determite if we should continue reading
Modifications:
- use contineReading(UncheckedBooleanSupplier) for DatagramChannels
Result:
Read more then once in the general case for DatagramChannels with the default config
Motivation:
Allow to configure the maximum number of messages to write per eventloop run. This can be useful to ensure we read data in a timely manner and not let writes dominate the CPU time. This is especially useful in protocols like QUIC where you need to read "fast enough" as otherwise you may not read the ACKs fast enough.
Modifications:
- Add new ChannelOption / config that allows to limit the number of messages to write per eventloop run.
- Respect this setting for DatagramChannels
Result:
Reduce the risk of having WRITES block the processing of other events in a timely manner
Co-authored-by: terrarier2111 <58695553+terrarier2111@users.noreply.github.com>
Motivation:
We need to ensure we also build the modules we depend on as otherwise we may not be able to resolve the dependencies correctly
Modifications:
- Add -am when calling maven
Result:
Deployment works all the time
Motivation:
SslHandler owns the responsibility to flush non-application data
(e.g. handshake, renegotiation, etc.) to the socket. However when
TCP Fast Open is supported but the client_hello cannot be written
in the SYN the client_hello may not always be flushed. SslHandler
may not wrap/flush previously written/flushed data in the event
it was not able to be wrapped due to NEED_UNWRAP state being
encountered in wrap (e.g. peer initiated renegotiation).
Modifications:
- SslHandler to flush in channelActive() if TFO is enabled and
the client_hello cannot be written in the SYN.
- SslHandler to wrap application data after non-application data
wrap and handshake status is FINISHED.
- SocketSslEchoTest only flushes when writes are done, and waits
for the handshake to complete before writing.
Result:
SslHandler flushes handshake data for TFO, and previously flushed
application data after peer initiated renegotiation finishes.
Motivation:
The EpollSocketConnectTest was not correctly configuring TCP Fast Open on the server socket.
It's an option, not a child option.
Modification:
EpollSocketConnectTest now correctly enables TCP Fast Open on the server side, when available, for the test that needs it.
Result:
Test covers what it was intended to.
Motivation:
There are several overloads of streamError(), with one receiving the
Throwable to be made the cause of the new exception. However, the wrong
overload was being called and instead the IllegalArgumentException was
being passed as a message format argument which was summarily thrown
away as the message format didn't reference it.
Modifications:
Move IllegalArgumentException to proper argument position.
Result:
A useful exception, with the underlying cause available.
Motivation:
As stated by https://tools.ietf.org/html/rfc7540#section-8.1.2.6 we should report a stream error if the content-length does not match the sum of all data frames.
Modifications:
- Verify that the sum of data frames match if a content-length header was send.
- Handle multiple content-length headers and also handle negative values
- Add io.netty.http2.validateContentLength system property which allows to disable the more strict validation
- Add unit tests
Result:
Correctly handle the case when the content-length header was included but not match what is send and also when content-length header is invalid
Motivation:
c22c6b845d introduced support for
UDP_SEGMENT but did restrict it to continous buffers. This is not needed
as it is also fine to use CompositeByteBuf
Modifications:
- Allow to use CompositeByteBuf as well
- Add unit test
Result:
More flexible usage of segmented datagrams possible
Motivation
The HttpObjectDecoder accepts input parameters for maxInitialLineLength
and maxHeaderSize. These are important variables since both message
components must be buffered in memory. As such, many decoders (like
Netty and others) introduce constraints. Due to their importance, many
users may wish to add instrumentation on the values of successful
decoder results, or otherwise be able to access these values to enforce
their own supplemental constraints.
While users can perhaps estimate the sizes today, they will not be
exact, due to the decoder being responsible for consuming optional
whitespace and the like.
Modifications
* Add HttpMessageDecoderResult class. This class extends DecoderResult
and is intended for HttpMessage objects successfully decoded by the
HttpObjectDecoder. It exposes attributes for the decoded
initialLineLength and headerSize.
* Modify HttpObjectDecoder to produce HttpMessageDecoderResults upon
successfully decoding the last HTTP header.
* Add corresponding tests to HttpRequestDecoderTest &
HttpResponseDecoderTest.
Co-authored-by: Bennett Lynch <Bennett-Lynch@users.noreply.github.com>
Motivation:
Add test to validate we are not affected by the regression introduced by fd8c1874b4
Modifications:
- Add unit test
Result:
Verify code works as expected
Motivation:
At the moment we use http to download rpms, let's switch to https
Modifications:
Use https for rpms
Result:
Hopefully more stable docker image builds
Motivation:
HttpObjectDecoder may throw an IllegalArgumentException if it encounters
a character that Character.isWhitespace() returns true for, but is not
one of the two valid OWS (optional whitespace) values. Such values may
not have friendly or readable toString() values. We should include the
hex value so that the illegal character can always be determined.
Modifications:
Add hex value as well
Result:
Easier to debug
Co-authored-by: Bennett Lynch <Bennett-Lynch@users.noreply.github.com>
Motivation:
These days we always include the OS in the library name. This means we also can simplify things
Modifications:
Adjust build configuration to address for libray name change
Result:
Simplify build
Motivation:
The DnsResolver default start address listen to "0.0.0.0", which may be not what the user wants.
Modification:
Add localAddress as a param of DnsNameResolver and its builder
Result:
The DnsNameResolver's bind address can be configured.
Motivation:
At the moment we don't support session caching on the client side at all when using the native SSL implementation. We should at least allow to enable it.
Modification:
Allow to enable session cache for client side but disable ti by default due a JDK bug atm.
Result:
Be able to cache sessions on the client side when using native SSL implementation .
Motivation:
Creating certificates from a byte[] while lazy parse it is general useful and is also needed by https://github.com/netty/netty-incubator-codec-quic/pull/141
Modifications:
Move classes, rename these and make them public
Result:
Be able to reuse code
Motivation:
Some of the features we want to support can only be supported by some of the SslContext implementations. We should allow to configure these in a consistent way the same way as we do it with Channel / ChannelOption
Modifications:
- Add SslContextOption and add builder methods that take these
- Add OpenSslContextOption and define two options there which are specific to openssl
Result:
More flexible configuration and implementation of SslContext
Motivation:
The JDK deflate implementation added support for operating on ByteBuffers in Java 11 or so.
This means that we don't need to restrict that implementation to ByteBufs that are heap based and can expose arrays.
Modification:
Add clauses to JdkZlibEncoder and JdkZlibDecoder for handling ByteBufs that don't have arrays, but do have one nioByteBuffer.
Expand the test coverage in JdkZlibTest to include all relevant combinations of buffer types and data types.
Result:
The JdkZlibEncoder and JdkZlibDecoder should now work on basically all non-composite ByteBufs, and likely also composite ByteBufs that have exactly one component.
Motivation:
This library is obsolete; hasn't been updated since 2013.
Modification:
Remove jzlib dependency, integration code and tests.
Result:
- No more jzlib support.
- Less code.
- The JdkZlib* code can now be simplified because it no longer share anything with jzlib.
Motivation:
In WriteTimeoutHandler we did make the assumption that the executor which is used to schedule the timeout is the same that is backing the write promise. This may not be true which will cause concurrency issues
Modifications:
Ensure we are on the right thread when try to modify the doubly-linked-list and if not schedule it on the right thread.
Result:
Fixes https://github.com/netty/netty/issues/11053
Motivation:
Channels need to have their configurations applied before we can call out to user-code via handlerAdded and initChannel.
Modification:
This adds tests for this behaviour, and fixes their failures.
Result:
Channel initialisers now have access to channel configuration and attributes.
Motivation:
We need to ensure that we call queue.remove() before we cal writeAndFlush() as this operation may cause an event that also touches the queue and remove from it. If we miss to do so we may see NoSuchElementExceptions.
Modifications:
- Call queue.remove() before calling writeAndFlush(...)
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/11046
This brings forward the build and release automation changes from 4.1 (#10879, #10883, #10884, #10886, #10888, #10889, #10893, #10900, #10933, #10945, #10966, #10968, #11002, and #11019) to 5.0.
Details are as follows:
* Use Github workflows for CI (#10879)
Motivation:
We should just use GitHub Actions for the CI
Modifications:
- Adjust docker / docker compose files
- Add different workflows and jobs to deploy and build the project
Result:
Don't depend on external CI services
* Fix non leak build condition
* Only use build and deploy workflows for 4.1 for now
* Add deploy job for cross compiled aarch64 (#10883)
Motivation:
We should also deploy snapshots for our cross compiled native jars.
Modifications:
- Add job and docker files for deploying cross compiled native jars
- Ensure we map the maven cache into our docker containers
Result:
Deploy aarch64 jars and re-use cache
* Use correct docker-compose file to deploy cross compiled artifacts
* Use correct docker-compose task to deploy for cross compiled artifacts
* Split pr and normal build (#10884)
Motivation:
We should better use seperate workflows for PR and normal builds
Modifications:
- Split workflows
- Better cache reuse
Result:
Cleanup
* Only deploy snapshots for one arch
Motivation:
We need to find a way to deploy SNAPSHOTS for different arch with the same timestamp. Otherwise it will cause problems.
See https://github.com/netty/netty/issues/10887
Modification:
Skip all other deploys then x86_64
Result:
Users are able to use SNAPSHOTS for x86_6
* Use maven cachen when running analyze job (#10888)
Motivation:
To prevent failures to problems while downloading dependencies we shoud cache these
Modifications:
Add maven cache
Result:
No more failures due problems while downloading dependencies
* Also include one PR job that uses boringssl (#10886)
Motivation:
When validating PRs we should also at least run one job that uses boringssl
Modifications:
- Add job that uses boringssl
- Cleanup docker compose files
- Fix buffer leak in test
Result:
Also run with boringssl when PRs are validated
* Use matrix for job configurations (#10889)
Motivation:
We can use the matrix feature to define our jobs. This reduces a lot of config
Modification:
Use job matrix
Result:
Easier to maintain
* Correctly deploy artifacts that are build on different archs (#10893)
Motivation:
We need to take special care when deploying snapshots as we need to generate the jars in multiple steps
Modifications:
- Use the nexus staging pluging to stage jars locally in multiple steps
- Add extra job that will merge these staged jars and deploy these
Result:
Fixes https://github.com/netty/netty/issues/10887
* Dont use cron for PRs
Motivation:
It doesnt make sense to use cron for PRs
Modifications:
Remove cron config
Result:
Cleanup
* We run all combinations when validate the PR, let's just use one type for normal push
Motivation:
Let us just only use one build config when building the 4.1 branch.
Modifications:
As we already do a full validation when doing the PR builds we can just only use one build config for pushes to the "main" branches
Result:
Faster build times
* Update action-docker-layer-caching (#10900)
Motivation:
We are three releases behind.
Modifications:
Update to latest version
Result:
Use up-to-date action-docker-layer-caching version
* Verify we can load native modules and add job that verifies on aarch64 as well (#10933)
Motivation:
As shown in the past we need to verify we actually can load the native as otherwise we may introduce regressions.
Modifications:
- Add new maven module which tests loading of native modules
- Add job that will also test loading on aarch64
Result:
Less likely to introduce regressions related to loading native code in the future
* Let script fail if one command fail (#10945)
Motivation:
We should use `set -e` to ensure we fail the script if one command fails.
Modifications:
Add set -e to script
Result:
Fail fast
* Use action to report unit test errors (#10966)
Motivation:
To make it easier to understand why the build fails lets use an action that will report which unit test failed
Modifications:
- Replace custom script with action-surefire-report
Result:
Easier to understand test failures
* Use custom script to check for build failures (#10968)
Motivation:
It turns out we can't use the action to check for build failures as it can't be used when a PR is done from a fork. Let's just use our simple script.
Modifications:
- Replace action with custom script
Result:
Builds for PRs that are done via forks work again.
* Publish test results after PR run (#11002)
Motivation:
To make it easier to understand why a build failed let us publish the rest results
Modifications:
Use a new workflow to be able to publish the test reports
Result:
Easier to understand why a PR did fail
* Fix test reports name
* Add workflow to cut releases (#11019)
Motivation:
Doing releases manually is error-prone, it would be better if we could do it via a workflow
Modification:
- Add workflow to cut releases
- Add related scripts
Result:
Be able to easily cut a release via a workflow
* Update build for master branch
Motivation:
The build changes were brought forward from 4.1, and contain many things specific to 4.1.
Modification:
Changed baseline Java version from 8 to 11, and changed branch references from "4.1" to "master".
Result:
Builds should now work for the master branch.
Co-authored-by: Norman Maurer <norman_maurer@apple.com>
Motivation:
For protocols like QUIC using UDP_SEGMENT (GSO) can help to reduce the
overhead quite a bit. We should support it.
Modifications:
- Add a SegmentedDatagramPacket which can be used to use UDP_SEGMENT
- Add unit test
Result:
Be able to make use of UDP_SEGMENT
Motivation:
To make it possible to experiment with alternative buffer implementations, we need a way to abstract away the concrete buffers used throughout most of the Netty pipelines, while still having a common currency for doing IO in the end.
Modification:
- Introduce an ByteBufConvertible interface, that allow arbitrary objects to convert themselves into ByteBuf objects.
- Every place in the code, where we did an instanceof check for ByteBuf, we now do an instanceof check for ByteBufConvertible.
- ByteBuf itself implements ByteBufConvertible, and returns itself from the asByteBuf method.
Result:
It is now possible to use Netty with alternative buffer implementations, as long as they can be converted to ByteBuf.
This has been verified elsewhere, with an alternative buffer implementation.
Motivation:
- Underlying buffer usages might be erroneous when releasing them internaly
in HttpPostMultipartRequestDecoder.
2 bugs occurs:
1) Final File upload seems not to be of the right size.
2) Memory, even in Disk mode, is increasing continuously, while it shouldn't.
- Method `getByte(position)` is too often called within the current implementation
of the HttpPostMultipartRequestDecoder.
This implies too much activities which is visible when PARANOID mode is active.
This is also true in standard mode.
Apply the same fix on buffer from HttpPostMultipartRequestDecoder to HttpPostStandardRequestDecoder
made previously.
Finally in order to ensure we do not rewrite already decoded HttpData when decoding
next ones within multipart, we must ensure the buffers are copied and not a retained slice.
Modification:
- Add some tests to check consistency for HttpPostMultipartRequestDecoder.
Add a package protected method for testing purpose only.
- Use the `bytesBefore(...)` method instead of `getByte(pos)` in order to limit the external
access to the underlying buffer by retrieving iteratively the beginning of a correct start
position.
It is used to find both LF/CRLF and delimiter.
2 methods in HttpPostBodyUtil were created for that.
The undecodedChunk is copied when adding a chunk to a DataMultipart is loaded.
The same buffer is also rewritten in order to release the copied memory part.
Result:
Just for note, for both Memory or Disk or Mixed mode factories, the release has to be done as:
for (InterfaceHttpData httpData: decoder.getBodyHttpDatas()) {
httpData.release();
factory.removeHttpDataFromClean(request, httpData);
}
factory.cleanAllHttpData();
decoder.destroy();
The memory used is minimal in Disk or Mixed mode. In Memory mode, a big file is still
in memory but not more in the undecodedChunk but its own buffer (copied).
In terms of benchmarking, the results are:
Original code Benchmark Mode Cnt Score Error Units
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigAdvancedLevel thrpt 6 0,152 ± 0,100 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigDisabledLevel thrpt 6 0,543 ± 0,218 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigParanoidLevel thrpt 6 0,001 ± 0,001 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigSimpleLevel thrpt 6 0,615 ± 0,070 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighAdvancedLevel thrpt 6 0,114 ± 0,063 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighDisabledLevel thrpt 6 0,664 ± 0,034 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighParanoidLevel thrpt 6 0,001 ± 0,001 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighSimpleLevel thrpt 6 0,620 ± 0,140 ops/ms
New code Benchmark Mode Cnt Score Error Units
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigAdvancedLevel thrpt 6 4,037 ± 0,358 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigDisabledLevel thrpt 6 4,226 ± 0,471 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigParanoidLevel thrpt 6 0,875 ± 0,029 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigSimpleLevel thrpt 6 4,346 ± 0,275 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighAdvancedLevel thrpt 6 2,044 ± 0,020 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighDisabledLevel thrpt 6 2,278 ± 0,159 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighParanoidLevel thrpt 6 0,174 ± 0,004 ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighSimpleLevel thrpt 6 2,370 ± 0,065 ops/ms
In short, using big file transfers, this is about 7 times faster with new code, while
using high number of HttpData, this is about 4 times faster with new code when using Simple Level.
When using Paranoid Level, using big file transfers, this is about 800 times faster with new code, while
using high number of HttpData, this is about 170 times faster with new code.
Motivation:
It is possible for two separate threads to race on recycling an object.
If this happens, the object might be added to a WeakOrderQueue when it shouldn't be.
The end result of this is that an object could be acquired multiple times, without a recycle in between.
Effectively, it ends up in circulation twice.
Modification:
We fix this by making the update to the lastRecycledId field of the handle, an atomic state transition.
Only the thread that "wins" the race and succeeds in their state transition will be allowed to recycle the object.
The others will bail out on their recycling.
We use weakCompareAndSet because we only need the atomicity guarantee, and the program order within each thread is sufficient.
Also, spurious failures just means we won't recycle that particular object, which is fine.
Result:
Objects no longer risk circulating twice due to a recycle race.
This fixes#10986
Motivation:
It is not uncommon to run Netty on OS X without the specific
`MacOSDnsServerAddressStreamProvider`. The current log message is too
verbose because it prints a full stack trace on the console while a
simple logging message would have been enough.
Modifications:
- Print a `WARN` message when `MacOSDnsServerAddressStreamProvider`
class is not found;
- Print a `ERROR` message with a stack trace when the class was found
but could not be loaded due to some other reasons;
Result:
Less noise in logs.
Motivation:
If two different headers end up in the same hash bucket, and you are iterating the header that is not the first in the bucket, and you use the iterator to remove the first element returned from the iterator, then you would get a NullPointerException.
Modification:
Change the DefaultHeaders iterator remove method, to re-iterate the hash bucket and unlink the entry once found, if we don't have any existing iteration starting point.
Also made DefaultHeaders.remove0 package private to avoid a synthetic method indirection.
Result:
Removing from iterators from DefaultHeaders is now robust towards hash collisions.
Motivation:
When TLSv1.3 is used (or TLS_FALSE_START) together with mTLS the handshake is considered successful before the server actually did verify the key material that was provided by the client. If the verification fails we currently will just close the stream without any extra information which makes it very hard to debug on the client side.
Modifications:
- Propagate SSLExceptions to the active streams
- Add unit test
Result:
Better visibility into why a stream was closed
Motivation:
#10995
when `io.netty.channel.unix.Socket` is ipv6 and join a multicast group with ipv4 address will cause `io.netty.channel.ChannelException: setsockopt() failed: Invalid argument` (at least in `Linux centos.dev 4.18.0-240.10.1.el8_3.x86_64 #1 SMP Mon Jan 18 17:05:51 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux`)
Modification:
check if target group address is ipv6 before call `io.netty.channel.epoll.LinuxSocket#joinGroup(java.net.InetAddress, java.net.NetworkInterface, java.net.InetAddress)`
I'm not sure if this modification is currect, but i checked source code of java NIO
```
Java_sun_nio_ch_Net_canJoin6WithIPv4Group0(JNIEnv* env, jclass cl)
{
#if defined(__APPLE__)
/* IPV6_ADD_MEMBERSHIP can be used to join IPv4 multicast groups */
return JNI_TRUE;
#else
/* IPV6_ADD_MEMBERSHIP cannot be used to join IPv4 multicast groups */
return JNI_FALSE;
#endif
}
```
seems ipv6 address can't join ipv4 group except osx
Result:
test on `Linux 3.10.0-514.el7.x86_64 #1 SMP Tue Nov 22 16:42:41 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux` exception ` setsockopt() failed: Invalid argument` has fixed
Fixes#10995
Motivation:
The `!fastOpen` part of `active || !fastOpen` is always false.
Modification:
- Remove `!fastOpen` and keep only `active` as a `flushAtEnd` flag for
`startHandshakeProcessing`;
- Update comment;
Result:
Simplified `flushAtEnd` flag computation in `SslHandler#handlerAdded`.
Support TCP Fast Open for clients and make SslHandler take advantage
Motivation:
- TCP Fast Open allow us to send a small amount of data along side the initial SYN packet when establishing a TCP connection.
- The TLS Client Hello packet is small enough to fit in there, and is also idempotent (another requirement for using TCP Fast Open), so if we can save a round-trip when establishing TLS connections when using TFO.
Modification:
- Add support for client-side TCP Fast Open for Epoll, and also lowers the Linux kernel version requirements to 3.6.
- When adding the SslHandler to a pipeline, if TCP Fast Open is enabled for the channel (and the channel is not already active) then start the handshake early by writing it to the outbound buffer.
- An important detail to note here, is that the outbound buffer is not flushed at this point, like it would for normal handshakes. The flushing happens later as part of establishing the TCP connection.
Result:
- It is now possible for clients (on epoll) to open connections with TCP Fast Open.
- The SslHandler automatically detects when this is the case, and now send its Client Hello message as part of the initial data in the TCP Fast Open flow when available, saving a round-trip when establishing TLS connections.
Co-authored-by: Colin Godsey <crgodsey@gmail.com>
