Add method to create ConnectionContext from Socket

[shirhatti]

As part of the scenario described by @kevin-montrose in #34344, we'd like for the sockets transport to create a connection context from an already accepted socket. In Kevin's example, the socket is accepted in another process before being marshalled over an IPC mechanism.

namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets
{
    public class SocketTransportFactory
    {
       public static ConnectionContext CreateConnectionContextFromSocket(Socket socket, SocketTransportOptions options);
    }
}

The consumer of this API will implement a custom IConnectionListenerFactory and will call this new static method in their IConnectionListener.AcceptAsync implementation

[davidfowl]

I'm not sure SocketTransportOptions makes sense here, we might need a new options type or something like this:

public class SocketTransportFactory
{
       public static ConnectionContext CreateConnectionContextFromSocket(Socket socket, 
                                                                         MemoryPool<byte> memoryPool = null, 
                                                                         PipeOptions inputOptions = null, 
                                                                         PipeOptions outputOptions = null, 
                                                                         waitForData = true);
}

[halter73]

I agree we should probably make a new options type. I think we should maintain the pools internally in a service making this API non static. This is necessary for internal pools like SocketSenderPool and nice-to-have if you just want to use the default internal PinnedBlockMemoryPool. How about this?

namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets
{
    // The implementation will also likely be disposable.
    public interface ISocketConnectionContextFactory
    {
        ConnectionContext CreateConnectionContextFromSocket(Socket socket, SocketConnectionOptions options);
    }

    // sealed? I could see extending this for a custom ISocketConnectionContextFactory.
    public class SocketConnectionOptions
    {
        public PipeOptions InputOptions { get; init; } = new PipeOptions();
        public PipeOptions OutputOptions { get; init; } = new PipeOptions();
        public MemoryPool<byte>? MemoryPool { get; init; } = null;
        
        // A mouthful, but consistent with SocketTransportOptions.
        public bool WaitForDataBeforeAllocatingBuffer { get; init; } = true;
    }

[shirhatti]

namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets
{
    // The implementation will also likely be disposable.
    public interface ISocketConnectionContextFactory
    {
        ConnectionContext Create(Socket socket, SocketConnectionOptions options);
    }

    // sealed? I could see extending this for a custom ISocketConnectionContextFactory.
    public sealed class SocketConnectionOptions
    {
        public PipeOptions InputOptions { get; init; } = new PipeOptions();
        public PipeOptions OutputOptions { get; init; } = new PipeOptions();
        
        // A mouthful, but consistent with SocketTransportOptions.
        public bool WaitForDataBeforeAllocatingBuffer { get; init; } = true;
        public bool DelaySocketOperations { get; init; } = false;
    }