refactor: Modular inbounds/outbounds

protocol/shadowsocks/inbound_relay.go

@@ -0,0 +1,152 @@
+package shadowsocks
+
+import (
+	"context"
+	"net"
+	"os"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/adapter/inbound"
+	"github.com/sagernet/sing-box/common/listener"
+	"github.com/sagernet/sing-box/common/mux"
+	"github.com/sagernet/sing-box/common/uot"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing-shadowsocks/shadowaead_2022"
+	"github.com/sagernet/sing/common"
+	"github.com/sagernet/sing/common/auth"
+	"github.com/sagernet/sing/common/buf"
+	E "github.com/sagernet/sing/common/exceptions"
+	F "github.com/sagernet/sing/common/format"
+	"github.com/sagernet/sing/common/logger"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+var _ adapter.TCPInjectableInbound = (*RelayInbound)(nil)
+
+type RelayInbound struct {
+	inbound.Adapter
+	ctx          context.Context
+	router       adapter.ConnectionRouterEx
+	logger       logger.ContextLogger
+	listener     *listener.Listener
+	service      *shadowaead_2022.RelayService[int]
+	destinations []option.ShadowsocksDestination
+}
+
+func newRelayInbound(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.ShadowsocksInboundOptions) (*RelayInbound, error) {
+	inbound := &RelayInbound{
+		Adapter:      inbound.NewAdapter(C.TypeShadowsocks, tag),
+		ctx:          ctx,
+		router:       uot.NewRouter(router, logger),
+		logger:       logger,
+		destinations: options.Destinations,
+	}
+	var err error
+	inbound.router, err = mux.NewRouterWithOptions(inbound.router, logger, common.PtrValueOrDefault(options.Multiplex))
+	if err != nil {
+		return nil, err
+	}
+	var udpTimeout time.Duration
+	if options.UDPTimeout != 0 {
+		udpTimeout = time.Duration(options.UDPTimeout)
+	} else {
+		udpTimeout = C.UDPTimeout
+	}
+	service, err := shadowaead_2022.NewRelayServiceWithPassword[int](
+		options.Method,
+		options.Password,
+		int64(udpTimeout.Seconds()),
+		adapter.NewUpstreamHandler(adapter.InboundContext{}, inbound.newConnection, inbound.newPacketConnection, inbound),
+	)
+	if err != nil {
+		return nil, err
+	}
+	err = service.UpdateUsersWithPasswords(common.MapIndexed(options.Destinations, func(index int, user option.ShadowsocksDestination) int {
+		return index
+	}), common.Map(options.Destinations, func(user option.ShadowsocksDestination) string {
+		return user.Password
+	}), common.Map(options.Destinations, option.ShadowsocksDestination.Build))
+	if err != nil {
+		return nil, err
+	}
+	inbound.service = service
+	inbound.listener = listener.New(listener.Options{
+		Context:                  ctx,
+		Logger:                   logger,
+		Network:                  options.Network.Build(),
+		Listen:                   options.ListenOptions,
+		ConnectionHandler:        inbound,
+		PacketHandler:            inbound,
+		ThreadUnsafePacketWriter: true,
+	})
+	return inbound, err
+}
+
+func (h *RelayInbound) Start() error {
+	return h.listener.Start()
+}
+
+func (h *RelayInbound) Close() error {
+	return h.listener.Close()
+}
+
+func (h *RelayInbound) NewConnectionEx(ctx context.Context, conn net.Conn, metadata adapter.InboundContext, onClose N.CloseHandlerFunc) {
+	err := h.service.NewConnection(ctx, conn, adapter.UpstreamMetadata(metadata))
+	N.CloseOnHandshakeFailure(conn, onClose, err)
+	if err != nil {
+		h.logger.ErrorContext(ctx, E.Cause(err, "process connection from ", metadata.Source))
+	}
+}
+
+func (h *RelayInbound) NewPacketEx(buffer *buf.Buffer, source M.Socksaddr) {
+	err := h.service.NewPacket(h.ctx, &stubPacketConn{h.listener.PacketWriter()}, buffer, M.Metadata{Source: source})
+	if err != nil {
+		h.logger.Error(E.Cause(err, "process packet from ", source))
+	}
+}
+
+func (h *RelayInbound) newConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error {
+	destinationIndex, loaded := auth.UserFromContext[int](ctx)
+	if !loaded {
+		return os.ErrInvalid
+	}
+	destination := h.destinations[destinationIndex].Name
+	if destination == "" {
+		destination = F.ToString(destinationIndex)
+	} else {
+		metadata.User = destination
+	}
+	h.logger.InfoContext(ctx, "[", destination, "] inbound connection to ", metadata.Destination)
+	metadata.Inbound = h.Tag()
+	metadata.InboundType = h.Type()
+	return h.router.RouteConnection(ctx, conn, metadata)
+}
+
+func (h *RelayInbound) newPacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext) error {
+	destinationIndex, loaded := auth.UserFromContext[int](ctx)
+	if !loaded {
+		return os.ErrInvalid
+	}
+	destination := h.destinations[destinationIndex].Name
+	if destination == "" {
+		destination = F.ToString(destinationIndex)
+	} else {
+		metadata.User = destination
+	}
+	ctx = log.ContextWithNewID(ctx)
+	h.logger.InfoContext(ctx, "[", destination, "] inbound packet connection from ", metadata.Source)
+	h.logger.InfoContext(ctx, "[", destination, "] inbound packet connection to ", metadata.Destination)
+	metadata.Inbound = h.Tag()
+	metadata.InboundType = h.Type()
+	metadata.InboundDetour = h.listener.ListenOptions().Detour
+	metadata.InboundOptions = h.listener.ListenOptions().InboundOptions
+	return h.router.RoutePacketConnection(ctx, conn, metadata)
+}
+
+func (h *RelayInbound) NewError(ctx context.Context, err error) {
+	NewError(h.logger, ctx, err)
+}