init

go-gost/x/handler/tun/handler.go

@@ -0,0 +1,116 @@
+package tun
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+	"sync"
+	"time"
+
+	"github.com/go-gost/core/chain"
+	"github.com/go-gost/core/handler"
+	"github.com/go-gost/core/hop"
+	md "github.com/go-gost/core/metadata"
+	ctxvalue "github.com/go-gost/x/ctx"
+	tun_util "github.com/go-gost/x/internal/util/tun"
+	"github.com/go-gost/x/registry"
+)
+
+var (
+	ErrTun        = errors.New("tun device error")
+	ErrInvalidNet = errors.New("invalid net IP")
+)
+
+func init() {
+	registry.HandlerRegistry().Register("tun", NewHandler)
+}
+
+type tunHandler struct {
+	hop     hop.Hop
+	routes  sync.Map
+	md      metadata
+	options handler.Options
+}
+
+func NewHandler(opts ...handler.Option) handler.Handler {
+	options := handler.Options{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	return &tunHandler{
+		options: options,
+	}
+}
+
+func (h *tunHandler) Init(md md.Metadata) (err error) {
+	if err = h.parseMetadata(md); err != nil {
+		return
+	}
+
+	return
+}
+
+// Forward implements handler.Forwarder.
+func (h *tunHandler) Forward(hop hop.Hop) {
+	h.hop = hop
+}
+
+func (h *tunHandler) Handle(ctx context.Context, conn net.Conn, opts ...handler.HandleOption) error {
+	defer conn.Close()
+
+	log := h.options.Logger
+
+	v, _ := conn.(md.Metadatable)
+	if v == nil {
+		err := errors.New("tun: wrong connection type")
+		log.Error(err)
+		return err
+	}
+	config := v.Metadata().Get("config").(*tun_util.Config)
+
+	start := time.Now()
+	log = log.WithFields(map[string]any{
+		"remote": conn.RemoteAddr().String(),
+		"local":  conn.LocalAddr().String(),
+		"sid":    ctxvalue.SidFromContext(ctx),
+	})
+
+	log.Infof("%s <> %s", conn.RemoteAddr(), conn.LocalAddr())
+	defer func() {
+		log.WithFields(map[string]any{
+			"duration": time.Since(start),
+		}).Infof("%s >< %s", conn.RemoteAddr(), conn.LocalAddr())
+	}()
+
+	var target *chain.Node
+	if h.hop != nil {
+		target = h.hop.Select(ctx)
+	}
+	if target != nil {
+		network := "udp"
+		if _, _, err := net.SplitHostPort(target.Addr); err != nil {
+			network = "ip"
+		}
+
+		log = log.WithFields(map[string]any{
+			"dst": fmt.Sprintf("%s/%s", target.Addr, network),
+		})
+		log.Debugf("%s >> %s", conn.RemoteAddr(), target.Addr)
+
+		if err := h.handleClient(ctx, conn, network, target.Addr, config, log); err != nil {
+			log.Error(err)
+		}
+		return nil
+	}
+
+	return h.handleServer(ctx, conn, config, log)
+}
+
+type tunRouteKey [16]byte
+
+func ipToTunRouteKey(ip net.IP) (key tunRouteKey) {
+	copy(key[:], ip.To16())
+	return
+}