gonat

type Addr struct {
	IPString string
	Port     uint16
}

type FiveTuple struct {
	IPProto uint8
	Src     Addr
	Dst     Addr
}

type IPPacket struct {
	Raw       bpool.ByteSlice
	IPVersion uint8
	IPProto   uint8
	SrcAddr   *net.IPAddr
	DstAddr   *net.IPAddr
	Header    []byte
	Payload   []byte
}

type Opts struct {
	// IFName is the name of the interface to use for connecting upstream.
	// If not specified, this will use the default interface for reaching the
	// Internet.
	IFName string

	// IFAddr is the address to use for outbound packets. Overrides the IFName
	// when specified.
	IFAddr string

	// BufferPool is a pool for buffers. If not provided, default to a 10MB pool.
	// Each []byte in the buffer pool should be <MaximumIPPacketSize> bytes.
	BufferPool bpool.ByteSlicePool

	// BufferDepth specifies the number of outbound packets to buffer between
	// stages in the send/receive pipeline. The default is <DefaultBufferDepth>.
	BufferDepth int

	// IdleTimeout specifies the amount of time before idle connections are
	// automatically closed. The default is <DefaultIdleTimeout>.
	IdleTimeout time.Duration

	// StatsTracker allows specifying an existing StatsTracker to use for tracking
	// stats. If not specified, one will be created using the configured StatsInterval.
	// Note - the StatsTracker has to be manually closed using its Close() method, otherwise
	// it will keep logging stats.
	StatsTracker *StatsTracker

	// StatsInterval controls how frequently to display stats. Defaults to
	// <DefaultStatsInterval>.
	StatsInterval time.Duration

	// OnOutbound allows modifying outbound ip packets.
	OnOutbound func(pkt *IPPacket)

	// OnInbound allows modifying inbound ip packets. ft is the 5 tuple to
	// which the current connection/UDP port mapping is keyed.
	OnInbound func(pkt *IPPacket, downFT FiveTuple)
}

type ReadWriter interface {
	// Read reads data into a ByteSlice
	Read(bpool.ByteSlice) (int, error)

	// Write writes data from a ByteSlice
	Write(bpool.ByteSlice) (int, error)
}

type ReadWriterAdapter struct {
	io.ReadWriter
}

type Server interface {
	// Serve starts processing packets and blocks until finished
	Serve() error

	// Close stops the server and cleans up resources
	Close() error
}

type StatsTracker struct {
	// contains filtered or unexported fields
}