refactor: Modular inbounds/outbounds

protocol/direct/outbound.go

@@ -0,0 +1,170 @@
+package direct
+
+import (
+	"context"
+	"net"
+	"net/netip"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/adapter/outbound"
+	"github.com/sagernet/sing-box/common/dialer"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing-dns"
+	"github.com/sagernet/sing/common/bufio"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+func RegisterOutbound(registry *outbound.Registry) {
+	outbound.Register[option.DirectOutboundOptions](registry, C.TypeDirect, NewOutbound)
+}
+
+var _ N.ParallelDialer = (*Outbound)(nil)
+
+type Outbound struct {
+	outbound.Adapter
+	logger              logger.ContextLogger
+	dialer              N.Dialer
+	domainStrategy      dns.DomainStrategy
+	fallbackDelay       time.Duration
+	overrideOption      int
+	overrideDestination M.Socksaddr
+	// loopBack *loopBackDetector
+}
+
+func NewOutbound(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.DirectOutboundOptions) (adapter.Outbound, error) {
+	options.UDPFragmentDefault = true
+	outboundDialer, err := dialer.New(router, options.DialerOptions)
+	if err != nil {
+		return nil, err
+	}
+	outbound := &Outbound{
+		Adapter:        outbound.NewAdapterWithDialerOptions(C.TypeDirect, []string{N.NetworkTCP, N.NetworkUDP}, tag, options.DialerOptions),
+		logger:         logger,
+		domainStrategy: dns.DomainStrategy(options.DomainStrategy),
+		fallbackDelay:  time.Duration(options.FallbackDelay),
+		dialer:         outboundDialer,
+		// loopBack:       newLoopBackDetector(router),
+	}
+	if options.ProxyProtocol != 0 {
+		return nil, E.New("Proxy Protocol is deprecated and removed in sing-box 1.6.0")
+	}
+	if options.OverrideAddress != "" && options.OverridePort != 0 {
+		outbound.overrideOption = 1
+		outbound.overrideDestination = M.ParseSocksaddrHostPort(options.OverrideAddress, options.OverridePort)
+	} else if options.OverrideAddress != "" {
+		outbound.overrideOption = 2
+		outbound.overrideDestination = M.ParseSocksaddrHostPort(options.OverrideAddress, options.OverridePort)
+	} else if options.OverridePort != 0 {
+		outbound.overrideOption = 3
+		outbound.overrideDestination = M.Socksaddr{Port: options.OverridePort}
+	}
+	return outbound, nil
+}
+
+func (h *Outbound) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
+	ctx, metadata := adapter.ExtendContext(ctx)
+	metadata.Outbound = h.Tag()
+	metadata.Destination = destination
+	switch h.overrideOption {
+	case 1:
+		destination = h.overrideDestination
+	case 2:
+		newDestination := h.overrideDestination
+		newDestination.Port = destination.Port
+		destination = newDestination
+	case 3:
+		destination.Port = h.overrideDestination.Port
+	}
+	network = N.NetworkName(network)
+	switch network {
+	case N.NetworkTCP:
+		h.logger.InfoContext(ctx, "outbound connection to ", destination)
+	case N.NetworkUDP:
+		h.logger.InfoContext(ctx, "outbound packet connection to ", destination)
+	}
+	/*conn, err := h.dialer.DialContext(ctx, network, destination)
+	if err != nil {
+		return nil, err
+	}
+	return h.loopBack.NewConn(conn), nil*/
+	return h.dialer.DialContext(ctx, network, destination)
+}
+
+func (h *Outbound) DialParallel(ctx context.Context, network string, destination M.Socksaddr, destinationAddresses []netip.Addr) (net.Conn, error) {
+	ctx, metadata := adapter.ExtendContext(ctx)
+	metadata.Outbound = h.Tag()
+	metadata.Destination = destination
+	switch h.overrideOption {
+	case 1, 2:
+		// override address
+		return h.DialContext(ctx, network, destination)
+	case 3:
+		destination.Port = h.overrideDestination.Port
+	}
+	network = N.NetworkName(network)
+	switch network {
+	case N.NetworkTCP:
+		h.logger.InfoContext(ctx, "outbound connection to ", destination)
+	case N.NetworkUDP:
+		h.logger.InfoContext(ctx, "outbound packet connection to ", destination)
+	}
+	var domainStrategy dns.DomainStrategy
+	if h.domainStrategy != dns.DomainStrategyAsIS {
+		domainStrategy = h.domainStrategy
+	} else {
+		domainStrategy = dns.DomainStrategy(metadata.InboundOptions.DomainStrategy)
+	}
+	return N.DialParallel(ctx, h.dialer, network, destination, destinationAddresses, domainStrategy == dns.DomainStrategyPreferIPv6, h.fallbackDelay)
+}
+
+func (h *Outbound) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
+	ctx, metadata := adapter.ExtendContext(ctx)
+	metadata.Outbound = h.Tag()
+	metadata.Destination = destination
+	originDestination := destination
+	switch h.overrideOption {
+	case 1:
+		destination = h.overrideDestination
+	case 2:
+		newDestination := h.overrideDestination
+		newDestination.Port = destination.Port
+		destination = newDestination
+	case 3:
+		destination.Port = h.overrideDestination.Port
+	}
+	if h.overrideOption == 0 {
+		h.logger.InfoContext(ctx, "outbound packet connection")
+	} else {
+		h.logger.InfoContext(ctx, "outbound packet connection to ", destination)
+	}
+	conn, err := h.dialer.ListenPacket(ctx, destination)
+	if err != nil {
+		return nil, err
+	}
+	// conn = h.loopBack.NewPacketConn(bufio.NewPacketConn(conn), destination)
+	if originDestination != destination {
+		conn = bufio.NewNATPacketConn(bufio.NewPacketConn(conn), destination, originDestination)
+	}
+	return conn, nil
+}
+
+/*func (h *Outbound) NewConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error {
+	if h.loopBack.CheckConn(metadata.Source.AddrPort(), M.AddrPortFromNet(conn.LocalAddr())) {
+		return E.New("reject loopback connection to ", metadata.Destination)
+	}
+	return NewConnection(ctx, h, conn, metadata)
+}
+
+func (h *Outbound) NewPacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext) error {
+	if h.loopBack.CheckPacketConn(metadata.Source.AddrPort(), M.AddrPortFromNet(conn.LocalAddr())) {
+		return E.New("reject loopback packet connection to ", metadata.Destination)
+	}
+	return NewPacketConnection(ctx, h, conn, metadata)
+}
+*/