refactor: Modular inbounds/outbounds

protocol/socks/outbound.go

@@ -0,0 +1,137 @@
+package socks
+
+import (
+	"context"
+	"net"
+
+	"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"
+	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"
+	"github.com/sagernet/sing/common/uot"
+	"github.com/sagernet/sing/protocol/socks"
+)
+
+func RegisterOutbound(registry *outbound.Registry) {
+	outbound.Register[option.SOCKSOutboundOptions](registry, C.TypeSOCKS, NewOutbound)
+}
+
+var _ adapter.Outbound = (*Outbound)(nil)
+
+type Outbound struct {
+	outbound.Adapter
+	router    adapter.Router
+	logger    logger.ContextLogger
+	client    *socks.Client
+	resolve   bool
+	uotClient *uot.Client
+}
+
+func NewOutbound(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.SOCKSOutboundOptions) (adapter.Outbound, error) {
+	var version socks.Version
+	var err error
+	if options.Version != "" {
+		version, err = socks.ParseVersion(options.Version)
+	} else {
+		version = socks.Version5
+	}
+	if err != nil {
+		return nil, err
+	}
+	outboundDialer, err := dialer.New(router, options.DialerOptions)
+	if err != nil {
+		return nil, err
+	}
+	outbound := &Outbound{
+		Adapter: outbound.NewAdapterWithDialerOptions(C.TypeSOCKS, options.Network.Build(), tag, options.DialerOptions),
+		router:  router,
+		logger:  logger,
+		client:  socks.NewClient(outboundDialer, options.ServerOptions.Build(), version, options.Username, options.Password),
+		resolve: version == socks.Version4,
+	}
+	uotOptions := common.PtrValueOrDefault(options.UDPOverTCP)
+	if uotOptions.Enabled {
+		outbound.uotClient = &uot.Client{
+			Dialer:  outbound.client,
+			Version: uotOptions.Version,
+		}
+	}
+	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 N.NetworkName(network) {
+	case N.NetworkTCP:
+		h.logger.InfoContext(ctx, "outbound connection to ", destination)
+	case N.NetworkUDP:
+		if h.uotClient != nil {
+			h.logger.InfoContext(ctx, "outbound UoT connect packet connection to ", destination)
+			return h.uotClient.DialContext(ctx, network, destination)
+		}
+		h.logger.InfoContext(ctx, "outbound packet connection to ", destination)
+	default:
+		return nil, E.Extend(N.ErrUnknownNetwork, network)
+	}
+	if h.resolve && destination.IsFqdn() {
+		destinationAddresses, err := h.router.LookupDefault(ctx, destination.Fqdn)
+		if err != nil {
+			return nil, err
+		}
+		return N.DialSerial(ctx, h.client, network, destination, destinationAddresses)
+	}
+	return h.client.DialContext(ctx, network, destination)
+}
+
+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
+	if h.uotClient != nil {
+		h.logger.InfoContext(ctx, "outbound UoT packet connection to ", destination)
+		return h.uotClient.ListenPacket(ctx, destination)
+	}
+	if h.resolve && destination.IsFqdn() {
+		destinationAddresses, err := h.router.LookupDefault(ctx, destination.Fqdn)
+		if err != nil {
+			return nil, err
+		}
+		packetConn, _, err := N.ListenSerial(ctx, h.client, destination, destinationAddresses)
+		if err != nil {
+			return nil, err
+		}
+		return packetConn, nil
+	}
+	h.logger.InfoContext(ctx, "outbound packet connection to ", destination)
+	return h.client.ListenPacket(ctx, destination)
+}
+
+// TODO
+// Deprecated
+func (h *Outbound) NewConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error {
+	if h.resolve {
+		return outbound.NewDirectConnection(ctx, h.router, h, conn, metadata, dns.DomainStrategyUseIPv4)
+	} else {
+		return outbound.NewConnection(ctx, h, conn, metadata)
+	}
+}
+
+// TODO
+// Deprecated
+func (h *Outbound) NewPacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext) error {
+	if h.resolve {
+		return outbound.NewDirectPacketConnection(ctx, h.router, h, conn, metadata, dns.DomainStrategyUseIPv4)
+	} else {
+		return outbound.NewPacketConnection(ctx, h, conn, metadata)
+	}
+}