Motivation:
CVE-2016-4970
OpenSslEngine.wrap calls SSL_write which may return SSL_ERROR_WANT_READ, and if in this condition there is nothing to read from the BIO the OpenSslEngine and SslHandler will enter an infinite loop.
Modifications:
- Use the error code provided by OpenSSL and go back to the EventLoop selector to detect if the socket is closed
Result:
OpenSslEngine correctly handles the return codes from OpenSSL and does not enter an infinite loop.
Motivation:
Http2ConnectionHandler will always send a GO_AWAY when the channel is closed. This may cause problems if the user is attempting to control when GO_AWAY is sent and the content of the GO_AWAY.
Modifications:
- When the channel is closed Http2ConnectionHandler should only send a GO_AWAY if one has not already been sent
Result:
The user has more control over when GO_AWAY is sent
Fixes https://github.com/netty/netty/issues/5307
Motivation:
Sometimes it may be benefitially for an user to specify a custom algorithm when choose the next EventExecutor/EventLoop.
Modifications:
Allow to specify a custom EventExecutorChooseFactory that allows to customize algorithm.
Result:
More flexible api.
Motivation:
We need to first store a reference to the wrapped buffer before recycle the AbstractPooledDerivedByteBuf instance. This is needed as otherwise it is possible that the same AbstractPooledDerivedByteBuf is again obtained and init(...) is called before we actually have a chance to call release(). This leads to call release() on the wrong buffer.
Modifications:
Store a reference to the wrapped buffer before call recycle and call release on the previous stored reference.
Result:
Always release the correct wrapped buffer when deallocate the AbstractPooledDerivedByteBuf.
Motivation:
We use a default of 3 for maxQueriesPerResolve when using the DnsNameResolverBuilder, which is too low if you want to resolve a hostname that uses a lot of CNAME records.
Modifications:
- Use higher default (16)
- Make exception message more clear why it failed.
Result:
Be able to resolve more domains by default and be able to better trouble shoot why a resolver failed.
Motivation:
We tried to always use SecureRandom to generate the initialSeed for our ThreadLocalRandom, this can sometimes give warnings under normal usage. We should better not use SecureRandom as default (just as the implementation in jsr166y does) and only try if the user specified -Djava.util.secureRandomSeed=true .
Modifications:
Only try to use SecureRandom when -Djava.util.secureRandomSeed=true is used.
Result:
Less likely to see entropy warnings.
Motivation:
If the user uses unsafe direct buffers with no cleaner we can use Unsafe.reallocateMemory(...) as optimization when we need to expand the buffer.
Modifications:
Use Unsafe.relocateMemory(...) in UnpooledUnsafeNoCleanerDirectByteBuf.
Result:
Less expensive expanding of buffers.
Motivation:
DnsAddressResolverGroup allows to override the newResolver(...) method to change the settings used by the user. We should better let the user override another method and always apply the InflightNameResolver.
Modifications:
- Mark newResolver(...) method as deprecated, we will make it private soon.
- Add newNameResolver(...) method that user can override.
Result:
Easier to extend DnsAddressResolverGroup
Motivation:
We should ensure we null out the cumulation buffer before we fire it through the pipleine in handlerRemoved(...) as in theory it could be possible that another method is triggered as result of the fireChannelRead(...) or fireChannelReadComplete() that will try to access the cumulation.
Modifications:
Null out cumulation buffer early in handlerRemoved(...)
Result:
No possible to access the cumulation buffer that was already handed over.
Motivation:
We need to ensure we not hold a lock while executor callHandlerRemoved(...) as this may lead to a deadlock if handlerRemoved(...) will call another method in DEfaultChannelPipeline from another thread that will need to obtain the lock as well and wait for the result.
Modifications:
Release the lock before call handlerRemoved0(...).
Result:
No more deadlock possible
Motivation:
We not correctly catched errors during resolving in bootstrap and so may not have notified the future correctly.
Modifications:
Move code into try / catch block and try to fail the promise.
Result:
Promise is always notified
Motivation:
We used transfered in native code which is not correct spelling. It should be transferred.
Modifications:
Fix typo.
Result:
Less typos in source code.
Motivation:
OpenSslEngine calls rejectRemoteInitiatedRenegation in a scenario where the number of handshakes has not been observed to change. The number of handshakes has only been observed to change after readPlaintextData is called.
Modifications:
- Remove the call to rejectRemoteInitiatedRenegation before calls to readPlaintextData
Result:
Less code.
Motivation:
InetSocketAddressResolver.close() must call close() on the wrapped NameResolver.
Modifications:
Correctly call close() on wrapped NameResolver and added test.
Result:
close() is correctly propergated to the wrapped resolver.
Motivation:
Using the Cleaner to release the native memory has a few drawbacks:
- Cleaner.clean() uses static synchronized internally which means it can be a performance bottleneck
- It put more load on the GC
Modifications:
Add new buffer implementations that can be enabled with a system flag as optimizations. In this case no Cleaner is used at all and the user must ensure everything is always released.
Result:
Less performance impact by direct buffers when need to be allocated and released.
Modifications:
DefaultPromise provides a ThreadLocal queue to protect against StackOverflowError because of executors which may immediately execute runnables instead of queue them (i.e. ImmediateEventExecutor). However this may be better addressed by fixing these executors to protect against StackOverflowError instead of just fixing for a single use case. Also the most commonly used executors already provide the desired behavior and don't need the additional overhead of a ThreadLocal queue in DefaultPromise.
Modifications:
- Remove ThreadLocal queue from DefaultPromise
- Change ImmediateEventExecutor so it maintains a queue of runnables if reentrant condition occurs
Result:
DefaultPromise StackOverflowError code is simpler, and ImmediateEventExecutor protects against StackOverflowError.
Motivation:
For example,
DefaultHttp2Headers headers = new DefaultHttp2Headers();
headers.add("key1", "value1");
headers.add("key1", "value2");
headers.add("key1", "value3");
headers.add("key2", "value4");
produces:
DefaultHttp2Headers[key1: value1key1: value2key1: value3, key2: value4]
while correctly it should be
DefaultHttp2Headers[key1: value1, key1: value2, key1: value3, key2: value4]
Modifications:
Change the toString() method to produce the beforementioned output.
Result:
toString() format is correct also for keys with multiple values.
Motivation:
For lack of a better way the SocketRstTest inspects the content of the exception message to check if a RST occurred. However on windows the exception message is different than on other Unix based platforms and the assertion statement fails.
Modifications:
- Hack another string check in the unit test
Result:
SocketRstTest passes on windows
Fixes https://github.com/netty/netty/issues/5335
Motivation:
Under very unlikely (however possible) circumstances, Recycler may leak
references. This happens _only_ when the object was already recycled
at least once (which means it's got written to the stack) and then
taken out again, and never returned.
The "never returned" part may be the fault of the user (forgotten
`finally` clause) or the situation when Recycler drops the possibly
youngest item itself.
Modifications:
Nullify the item taken from the stack.
Result:
Reference is cleaned up. If the object is lost, it will be a subject for
GC. The rest of Stack / Recycler functionality remains unaffected.
Motivation:
Sometimes people may want to trade GC with memory overhead. For this it can be useful to allow to change the capacity of the array that is hold in the Link that is used by the Recycler internally.
Modifications:
Introduce a new system property , io.netty.recycler.linkCapacity which allows to change the capcity.
Result:
More flexible configuration of netty.
Motivation:
The user may specify to use a different allocator then the default. In this case we need to ensure it is shared when creating the EmbeddedChannel inside of a ChannelHandler
Modifications:
Use the config of the "original" Channel in the EmbeddedChannel and so share the same allocator etc.
Result:
Same type of buffers are used.
Motivation:
Currenlty, netty-transport-native-epoll-*-linux-x86_64.jar is not packed as OSGi bundle
and thus not working in OSGi environment.
Modifications:
In netty-transport-native-epoll's pom.xml added configuration
to attach manifest to the jar with a native library.
In netty-common's pom.xml added configuration instruction (DynamicImport-Package)
to maven bnd plugin to make sure the native code is loaded from
netty-transport-native-epoll bundle.
Result:
The netty-transport-native-epoll-*-linux-x86_64.jar is a bundle (MANIFEST.MF attached)
and the inluced native library can be successfuly loaded in OSGi environment.
Fixing #5119
Motivation:
Unsafe offers a method to set memory to a specific value. This can be used to implement an optimized version of setZero(...) and writeZero(...)
Modifications:
Add implementation for all Unsafe*ByteBuf implementations.
Result:
Faster setZero(...) and writeZero(...)
Motivation:
There is a small race while adding handlers to the pipeline because callHandlerAddedForAllHandlers() may not be run when the user calls add* but the Channel is already registered.
Modifications:
Ensure we always delay handlerAdded(..) / handlerRemoved(...) until callHandlerAddedForAllHandlers() was called.
Result:
No more race on pipeline modifications possible.
Motivation:
We can remove the volatile keyword from the cached Runnables as at worse these will just be re-created.
Modifications:
Remove volatile.
Result:
Less overhead.
Motivation:
When netty is used with open ssl provider and client authentication the following errors can occur:
error:140D9115:SSL routines:ssl_get_prev_session:session id context uninitialized
error:140A1175:SSL routines:ssl_bytes_to_cipher_list:inappropriate fallback
error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown protocol
Modifications:
Set the session id context in OpenSslServerContext so that sessions which use client authentication
which are cached have the same context id value.
Result:
Client authentication now works with open ssl provider.
Motivation:
SingleThreadEventExecutor.pendingTasks() will call taskQueue.size() to get the number of pending tasks in the queue. This is not safe when using MpscLinkedQueue as size() is only allowed to be called by a single consumer.
Modifications:
Ensure size() is only called from the EventLoop.
Result:
No more livelock possible when call pendingTasks, no matter from which thread it is done.
Motivation:
maven-dependency-plugin will include dependencies of all scopes by default. We should limit the scope to avoid pulling test dependencies. See #5317.
Modifications:
Add includeScope to avoid pulling test dependencies.
Result:
netty-all doesn't include codes from netty-build
Motivation:
Performing a server upgrade with a new initial flow control window will cause an NPE in the DefaultHttp2RemoteFlowController. This is due to the fact that the monitor does not check whether or not the channel is writable.
Modifications:
Added a check for channel writability before calling `writePendingBytes`. Also fixed a unit test that was supposed to be testing this :).
Result:
Fixes#5301
Motivation:
f2ed3e6ce8 removed the previous mechanism for StackOverflowError because it didn't work in all cases (i.e. ImmediateExecutor). However if a chain of listeners which complete other promises is formed there is still a possibility of a StackOverflowError.
Modifications:
- Use a ThreadLocal to save any DefaultPromises which could not be notified due to the stack being too large. After the first DefaultPromise on the stack completes notification this ThreadLocal should be used to notify any DefaultPromises which have not yet been notified.
Result:
DefaultPromise has StackOverflowError protection that works with all EventExecutor types.
Motivation:
If the executor changes while listeners are added and notification of listeners is being done then listeners can be notified out of order and concurrently. We should ensure that only one executor is used at any given time to notify listeners and ensure the listeners are notified in FIFO order.
Modifications:
- Move the notifyingListeners member variable from DefaultPromise into the synchronized block to prevent concurrent notification of listeners and preserve FIFO notification order
Result:
If the executor is changed for a DefaultPromise the listener notification order should be FIFO.
Motivation:
While doing 8fe3c83e4c I made a change which disallowed using null as name for handlers in the pipeline (this generated a new name before).
Modifications:
Revert to old behaviour and adding test case.
Result:
Allow null name again
Motivation:
At the moment the user is responsible to increase the writer index of the composite buffer when a new component is added. We should add some methods that handle this for the user as this is the most popular usage of the composite buffer.
Modifications:
Add new methods that autoamtically increase the writerIndex when buffers are added.
Result:
Easier usage of CompositeByteBuf.
Motivation:
EventLoopGroup.register doesn't need the Channel paramter when ChannelPromise is provided as we can get the Channel from ChannelPromise. Resolves#2422.
Modifications:
- Add EventLoopGroup.register(ChannelPromise)
- Deprecate EventLoopGroup.register(Channel, ChannelPromise)
Result:
EventLoopGroup.register is more convenient as people only need to set one parameter.
Motivation:
DefaultChannelPipeline was tightly coupled to AbstractChannel which is not really needed.
Modifications:
Move logic of calling handlerAdded(...) for handlers that were added before the Channel was registered to DefaultChannelPipeline by making it part of the head context.
Result:
Less coupling and so be able to use DefaultChannelPipeline also with other Channel implementations that not extend AbstractChannel
Motivation:
We do a "blind" cast to AbstractChannel in AbstractChannelHandlerContext which we should better no do. It would be better to decouble AbstractChannelHandlerContext from AbstractChannel.
Modifications:
Decouble AbstractChannelHandlerContext from AbstractChannel by move logic to DefaultChannelPipeline
Result:
Less coubling and less casting.
Motivation:
If the user will use addLast(...) on the ChannelPipeline of EmbeddedChannel after its constructor was run it will break the EmbeddedChannel as it will not be able to collect inbound messages and exceptions.
Modifications:
Ensure addLast(...) work as expected by move the logic of handling messages and exceptions ti protected methods of DefaultChannelPipeline and use a custom implementation for EmbeddedChannel
Result:
addLast(...) works as expected when using EmbeddedChannel.
Motivation:
We missed to override a few methods and so some actions on the ByteBuf failed.
Modifications:
- Override all methods
- Add unit tests to ensure all is fixed.
Result:
All *LeakAware*ByteBuf have correct implementations
Motivation:
Recycler.recycle(...) should not be used anymore and be replaced by Handle.recycle().
Modifications:
Mark it as deprecated and update usage.
Result:
Correctly document deprecated api.
Motivation:
Some tests in PooledByteBufAllocatorTest are blocking on a CountDownLatch. We should use a timeout on these tests so these will not block forever on a failure.
Modifications:
Add timeout param to @Test annotation
Result:
Have sane timeouts on tests.
