* Add NIOAsyncChannel based connect methods to ClientBootstrap
# Motivation
In my previous PR, I added new `bind` methods to `ServerBootstrap` that vend `NIOAsyncChannel` or support an async protocol negotiation. This PR focuses on adding new `connect` methods to `ClientBootstrap` which offer the same functionality.
# Modification
This PR adds new `connect` methods that either vend a `NIOAsyncChannel` or an asynchronous protocol negotiation result. To make this work I had to change the `HappyEyeballs` resolver so that it can return a generic value on resolving. Lastly, I adapted the bootstrap tests to use the new `ClientBootstrap` capabilities which now demonstrate a client/server protocol negotiation dance.
# Result
We can now bootstrap TCP clients with `NIOAsyncChannel`s
* Reduce code duplication
* Create a new set of APIs to tunnel an arbitrary Sendable payload through the inits
* Pass EL to closure
* Fix documentation
* Add `AsyncChannel` based `ServerBootstrap.bind()` methods
# Motivation
In my previous PR, we added a new async bridge from a NIO `Channel` to Swift Concurrency primitives in the from of the `NIOAsyncChannel`. This type alone is already helpful in bridging `Channel`s to Concurrency; however, it is hard to use since it requires to wrap the `Channel` at the right time otherwise we will drop reads. Furthermore, in the case of protocol negotiation this becomes even trickier since we need to wait until it finishes and then wrap the `Channel`.
# Modification
This PR introduces a few things:
1. New methods on the `ServerBootstrap` which allow the creation of `NIOAsyncChannel` based channels. This can be used in all cases where no protocol negotiation is involved.
2. A new protocol and type called `NIOProtocolNegotiationHandler` and `NIOProtocolNegotiationResult` which is used to identify channel handlers that are doing protocol negotiation.
3. New methods on the `ServerBootstrap` that are aware of protocol negotiation.
# Result
We can now easily and safely create new `AsyncChannel`s from the `ServerBootstrap`
* Code review
* Fix typo
* Fix up tests
* Stop finishing the writer when an error is caught
* Code review
* Fix up writer tests
* Introduce shared protocol negotiation handler state machine
* Correctly handle multi threaded event loops
* Adapt test to assert the channel was closed correctly.
* Code review
* RawSocket prototype
* Conform `ProtocolSubtype` to `Hashable`
* Add public `NIOIPProtocol` type
Make `ProtocolSubtype` internal
* Subset of IANA protocols with an RFC
* Add `CustomStringConvertible` to `NIOIPProtocol`
* Add `init(_ rawValue: Int)`
* Rename `NIOBSDSocket.ProtocolSubtype.ip` to `.default`
* Add `NIOBSDSocket.ProtocolSubtype.mptcp`
and remove `NIOBSDSocket.mptcpProtocolSubtype`
Motivation
MPTCP provides multipath capability for TCP connections. This
allows TCP connections to consume multiple independent network
paths, providing devices with a number of capabilities to
improve throughput, latency, or reliability.
MPTCP is not totally transparent, and requires servers to support
the functionality as well as clients. To that end, we should expose
some MPTCP capability.
Importantly, MPTCP uses a number of new socket flags and options.
To enable us to support this when it is available but gracefully fail
when it is not, we've hardcoded a number of Linux kernel constants
instead of relying on libc to expose them. This is safe to do on Linux
because its syscall layer is ABI stable.
Modifications
- Add ClientBootstrap and ServerBootstrap flags for MPTCP
- Plumb MPTCP through the stack
- Add new socket options for MPTCP
Result
MPTCP is supported on Linux
Use Win32 APIs to properly validate if a file is a pipe on Windows.
This enables providing the same semantics without leaking additional
Windows specifics.
Co-authored-by: Cory Benfield <lukasa@apple.com>
Replace the use of raw constants with the internal enumeration. This
ensures that the constant names are uniform and don't leak structural
information from the underlying information.
Use the wrapper function for duplicating the file descriptor. This
allows us to swap out the implementation for different targets making
the code more portable. It additionally adds additional error handling
and checking as the wrappers are intended to perform error handling.
Co-authored-by: Cory Benfield <lukasa@apple.com>
* socket: Make destinationPtr param optional in sendmsg(...)
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: Fixup documentation: scalar writes use sendmsg, not sendto
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: Make sockaddr pointer param optional in scalarWriteOperation
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: Add isConnected property to PendingDatagramWritesState
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: If socket is connected use NULL msg_name in sendmsg(2)
Signed-off-by: Si Beaumont <beaumont@apple.com>
* BaseSocketChannel: Support connect after bind
Signed-off-by: Si Beaumont <beaumont@apple.com>
* DatagramChannel: Implement connectSocket(to:)
Signed-off-by: Si Beaumont <beaumont@apple.com>
* bootstrap: Rename bind0(makeChannel:registerAndBind:) to withNewChannel(makeChannel:bringup:)
Signed-off-by: Si Beaumont <beaumont@apple.com>
* bootstrap: Add set of DatagramBootstrap.connect(...) APIs
Signed-off-by: Si Beaumont <beaumont@apple.com>
* test: Remove DatagramChannelTests.testConnectionFails
Signed-off-by: Si Beaumont <beaumont@apple.com>
* test: Add ConnectedDatagramChannelTests, inheriting from DatagramChannelTests
Signed-off-by: Si Beaumont <beaumont@apple.com>
* NIOUDPEchoClient: Use connected-mode UDP
Signed-off-by: Si Beaumont <beaumont@apple.com>
* soundness: Update copyright notice
Signed-off-by: Si Beaumont <beaumont@apple.com>
* fixup: cleanup bootstrap APIs
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: Check address of pending write if connected and add test
Signed-off-by: Si Beaumont <beaumont@apple.com>
* Revert "pdwm: Check address of pending write if connected and add test"
This reverts commit a4ee0756d5.
* channel: Fail buffered writes on connect and validate writes when connected
Signed-off-by: Si Beaumont <beaumont@apple.com>
* Run soundness.sh to get linux tests generated
Signed-off-by: Si Beaumont <beaumont@apple.com>
* NIOUDPEchoClient: Connect socket to remote only if --connect is used
Signed-off-by: Si Beaumont <beaumont@apple.com>
* socket: Support ByteBuffer (without AddressedEnvelope) for DatagramChannel
Signed-off-by: Si Beaumont <beaumont@apple.com>
* test: Simplify some test code
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: Factor out common, private add(_ pendingWrite:)
Signed-off-by: Si Beaumont <beaumont@apple.com>
* channel: Support AddressedEnvelope on connected socket for control messages
Signed-off-by: Si Beaumont <beaumont@apple.com>
* channel: Defer to common unwrapData for error handling
Signed-off-by: Si Beaumont <beaumont@apple.com>
* channel: Throw more specific (new) errors, instead of IOError
Signed-off-by: Si Beaumont <beaumont@apple.com>
* SocketChannelLifecycleManager: Add supportsReconnect boolean property, used in DatagramChannel
Signed-off-by: Si Beaumont <beaumont@apple.com>
Motivation:
Currently you cannot create a NIOPipeBootstrap when you are on
an event loop due to a precondition check. This check seeks to prevent
consumers of the API from passing in a file descriptor thats referencing
a file on disk or on the network.
The method at hand 'validateFileDescriptorIsNotAFile' uses fstat, which potentially
could block the event loop especially if the fd is referencing a file over the network.
This check however prevents certain use cases of SwiftNIO, where the downsides
of a consumer of this api blocking their own event loop do not weigh in against preventing
an entire use case from SwiftNIO.
Modifications:
Removed the precondition
Result:
After this change it will be possible to feed file descriptors into
the bootstrap which potentially block the current event loop.
A potential (portable) replacement for fstat still has to be found in order to solve this problem completely.
Motivation:
The remaining NIO code really conceptually belongs in a module called
NIOPosix, and NIOCore should really be called NIO. We can't really do
that last step, but we can prepare by pushing the bulk of the remaining
code into a module called NIOPosix.
Modifications:
- Move NIO to NIOPosix
- Make NIO an umbrella module.
Result:
NIOPosix exists.
Franz Busch