transport

type BidirectionalStream interface {
	CloseWrite() error
}

type Dialer interface {
	Dial(ctx context.Context, remoteAddr string) (net.Conn, error)
}

type Layer interface {
	// Listen binds the given IPv4:port localAddr on the
	// given network ("tcp" or "udp") and returns a
	// handler for accepting connections into that port.
	// The port is said to be on the "listen" mode, which
	// allows it to receive incoming connections.
	//
	// The IPv4 part of the address is optional, and if present
	// should match the IP address of one of the underlying
	// network interfaces. This means that the port will
	// only accept incoming connections targeted to this
	// IP address.
	//
	// If the port "0" is used, a random
	// port will be chosen.
	Listen(ctx context.Context, network, localAddr string) (net.Listener, error)

	// Dial starts a connection with the given IPv4:port remoteAddr
	// on the given network ("tcp" or "udp") and returns a handler
	// for reading and writing data from/into this connection.
	// The local port is chosen at random and will not accept
	// any incoming connections.
	//
	// For UDP, creating a connection
	// means just binding the dst IPv4:port address to the
	// connection handler (there's no handshake).
	//
	// DNS resolution is not support yet.
	Dial(ctx context.Context, network, remoteAddr string) (net.Conn, error)
	Dialer() LayerDialer

	// Close makes the transport layer stop listening to
	// IP datagrams received and provided by the network
	// layer. It does not close the network layer, it only
	// causes the underlying call to network.Layer.Listen()
	// to return, releasing the Recv() channels of the
	// underlying network interfaces to be taken over by
	// something else, like a new instance of the transport
	// layer.
	Close() error
}

type LayerDialer interface {
	Dialer
	WithLocalAddr(localAddr net.Addr) LayerDialer
}