sing-box/protocol/socks/inbound.go

package socks

import (
	std_bufio "bufio"
	"context"
	"net"
	"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/uot"
	C "github.com/sagernet/sing-box/constant"
	"github.com/sagernet/sing-box/log"
	"github.com/sagernet/sing-box/option"
	"github.com/sagernet/sing/common/auth"
	E "github.com/sagernet/sing/common/exceptions"
	"github.com/sagernet/sing/common/logger"
	N "github.com/sagernet/sing/common/network"
	"github.com/sagernet/sing/protocol/socks"
	"github.com/sagernet/sing/service"
)

func RegisterInbound(registry *inbound.Registry) {
	inbound.Register[option.SocksInboundOptions](registry, C.TypeSOCKS, NewInbound)
}

var _ adapter.TCPInjectableInbound = (*Inbound)(nil)

type Inbound struct {
	inbound.Adapter
	router        adapter.ConnectionRouterEx
	logger        logger.ContextLogger
	listener      *listener.Listener
	authenticator *auth.Authenticator
	udpTimeout    time.Duration
	userManager   adapter.UserManager
}

func NewInbound(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.SocksInboundOptions) (adapter.Inbound, error) {
	var udpTimeout time.Duration
	if options.UDPTimeout != 0 {
		udpTimeout = time.Duration(options.UDPTimeout)
	} else {
		udpTimeout = C.UDPTimeout
	}
	authenticator := auth.NewAuthenticator(options.Users)
	userManager := service.FromContext[adapter.UserManager](ctx)
	if userManager != nil {
		creds, err := userManager.GetCredentials(C.TypeSOCKS)
		if err == nil && len(creds) > 0 {
			users := make([]auth.User, len(creds))
			for i, c := range creds {
				users[i] = auth.User{Username: c.Username, Password: c.Credential}
			}
			authenticator = auth.NewAuthenticator(users)
		}
	}
	inbound := &Inbound{
		Adapter:       inbound.NewAdapter(C.TypeSOCKS, tag),
		router:        uot.NewRouter(router, logger),
		logger:        logger,
		authenticator: authenticator,
		udpTimeout:    udpTimeout,
		userManager:   userManager,
	}
	inbound.listener = listener.New(listener.Options{
		Context:           ctx,
		Logger:            logger,
		Network:           []string{N.NetworkTCP},
		Listen:            options.ListenOptions,
		ConnectionHandler: inbound,
	})
	return inbound, nil
}

func (h *Inbound) Start(stage adapter.StartStage) error {
	if stage != adapter.StartStateStart {
		return nil
	}
	if h.userManager != nil {
		go h.credentialLoop()
	}
	return h.listener.Start()
}

func (h *Inbound) credentialLoop() {
	ticker := time.NewTicker(30 * time.Second)
	defer ticker.Stop()
	for range ticker.C {
		creds, err := h.userManager.GetCredentials(C.TypeSOCKS)
		if err != nil || len(creds) == 0 {
			continue
		}
		users := make([]auth.User, len(creds))
		for i, c := range creds {
			users[i] = auth.User{Username: c.Username, Password: c.Credential}
		}
		h.authenticator = auth.NewAuthenticator(users)
	}
}

func (h *Inbound) Close() error {
	return h.listener.Close()
}

func (h *Inbound) NewConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext, onClose N.CloseHandlerFunc) {
	err := socks.HandleConnectionEx(ctx, conn, std_bufio.NewReader(conn), h.authenticator, adapter.NewUpstreamHandler(metadata, h.newUserConnection, h.streamUserPacketConnection), h.listener, h.udpTimeout, metadata.Source, onClose)
	N.CloseOnHandshakeFailure(conn, onClose, err)
	if err != nil {
		if E.IsClosedOrCanceled(err) {
			h.logger.DebugContext(ctx, "connection closed: ", err)
		} else {
			h.logger.ErrorContext(ctx, E.Cause(err, "process connection from ", metadata.Source))
		}
	}
}

func (h *Inbound) newUserConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext, onClose N.CloseHandlerFunc) {
	metadata.Inbound = h.Tag()
	metadata.InboundType = h.Type()
	user, loaded := auth.UserFromContext[string](ctx)
	if !loaded {
		h.logger.InfoContext(ctx, "inbound connection to ", metadata.Destination)
		h.router.RouteConnectionEx(ctx, conn, metadata, onClose)
		return
	}
	metadata.User = user
	h.logger.InfoContext(ctx, "[", user, "] inbound connection to ", metadata.Destination)
	h.router.RouteConnectionEx(ctx, conn, metadata, onClose)
}

func (h *Inbound) streamUserPacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext, onClose N.CloseHandlerFunc) {
	metadata.Inbound = h.Tag()
	metadata.InboundType = h.Type()
	user, loaded := auth.UserFromContext[string](ctx)
	if !loaded {
		if !metadata.Destination.IsValid() {
			h.logger.InfoContext(ctx, "inbound packet connection")
		} else {
			h.logger.InfoContext(ctx, "inbound packet connection to ", metadata.Destination)
		}
		h.router.RoutePacketConnectionEx(ctx, conn, metadata, onClose)
		return
	}
	metadata.User = user
	if !metadata.Destination.IsValid() {
		h.logger.InfoContext(ctx, "[", user, "] inbound packet connection")
	} else {
		h.logger.InfoContext(ctx, "[", user, "] inbound packet connection to ", metadata.Destination)
	}
	h.router.RoutePacketConnectionEx(ctx, conn, metadata, onClose)
}