add port range support for service

chain/router.go

@@ -0,0 +1,205 @@
+package chain
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/go-gost/core/chain"
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/core/recorder"
+	xnet "github.com/go-gost/x/internal/net"
+)
+
+type Router struct {
+	options chain.RouterOptions
+}
+
+func NewRouter(opts ...chain.RouterOption) *Router {
+	r := &Router{}
+	for _, opt := range opts {
+		if opt != nil {
+			opt(&r.options)
+		}
+	}
+	if r.options.Timeout == 0 {
+		r.options.Timeout = 15 * time.Second
+	}
+
+	if r.options.Logger == nil {
+		r.options.Logger = logger.Default().WithFields(map[string]any{"kind": "router"})
+	}
+	return r
+}
+
+func (r *Router) Options() *chain.RouterOptions {
+	if r == nil {
+		return nil
+	}
+	return &r.options
+}
+
+func (r *Router) Dial(ctx context.Context, network, address string) (conn net.Conn, err error) {
+	if r.options.Timeout > 0 {
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(ctx, r.options.Timeout)
+		defer cancel()
+	}
+
+	host := address
+	if h, _, _ := net.SplitHostPort(address); h != "" {
+		host = h
+	}
+	r.record(ctx, recorder.RecorderServiceRouterDialAddress, []byte(host))
+
+	conn, err = r.dial(ctx, network, address)
+	if err != nil {
+		r.record(ctx, recorder.RecorderServiceRouterDialAddressError, []byte(host))
+		return
+	}
+
+	if network == "udp" || network == "udp4" || network == "udp6" {
+		if _, ok := conn.(net.PacketConn); !ok {
+			return &packetConn{conn}, nil
+		}
+	}
+	return
+}
+
+func (r *Router) record(ctx context.Context, name string, data []byte) error {
+	if len(data) == 0 {
+		return nil
+	}
+
+	for _, rec := range r.options.Recorders {
+		if rec.Record == name {
+			err := rec.Recorder.Record(ctx, data)
+			if err != nil {
+				r.options.Logger.Errorf("record %s: %v", name, err)
+			}
+			return err
+		}
+	}
+	return nil
+}
+
+func (r *Router) dial(ctx context.Context, network, address string) (conn net.Conn, err error) {
+	count := r.options.Retries + 1
+	if count <= 0 {
+		count = 1
+	}
+	r.options.Logger.Debugf("dial %s/%s", address, network)
+
+	for i := 0; i < count; i++ {
+		var ipAddr string
+		ipAddr, err = xnet.Resolve(ctx, "ip", address, r.options.Resolver, r.options.HostMapper, r.options.Logger)
+		if err != nil {
+			r.options.Logger.Error(err)
+			break
+		}
+
+		var route chain.Route
+		if r.options.Chain != nil {
+			route = r.options.Chain.Route(ctx, network, ipAddr, chain.WithHostRouteOption(address))
+		}
+
+		if r.options.Logger.IsLevelEnabled(logger.DebugLevel) {
+			buf := bytes.Buffer{}
+			for _, node := range routePath(route) {
+				fmt.Fprintf(&buf, "%s@%s > ", node.Name, node.Addr)
+			}
+			fmt.Fprintf(&buf, "%s", ipAddr)
+			r.options.Logger.Debugf("route(retry=%d) %s", i, buf.String())
+		}
+
+		if route == nil {
+			route = DefaultRoute
+		}
+		conn, err = route.Dial(ctx, network, ipAddr,
+			chain.InterfaceDialOption(r.options.IfceName),
+			chain.NetnsDialOption(r.options.Netns),
+			chain.SockOptsDialOption(r.options.SockOpts),
+			chain.LoggerDialOption(r.options.Logger),
+		)
+		if err == nil {
+			break
+		}
+		r.options.Logger.Errorf("route(retry=%d) %s", i, err)
+	}
+
+	return
+}
+
+func (r *Router) Bind(ctx context.Context, network, address string, opts ...chain.BindOption) (ln net.Listener, err error) {
+	if r.options.Timeout > 0 {
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(ctx, r.options.Timeout)
+		defer cancel()
+	}
+
+	count := r.options.Retries + 1
+	if count <= 0 {
+		count = 1
+	}
+	r.options.Logger.Debugf("bind on %s/%s", address, network)
+
+	for i := 0; i < count; i++ {
+		var route chain.Route
+		if r.options.Chain != nil {
+			route = r.options.Chain.Route(ctx, network, address)
+			if route == nil || len(route.Nodes()) == 0 {
+				err = ErrEmptyRoute
+				return
+			}
+		}
+
+		if r.options.Logger.IsLevelEnabled(logger.DebugLevel) {
+			buf := bytes.Buffer{}
+			for _, node := range routePath(route) {
+				fmt.Fprintf(&buf, "%s@%s > ", node.Name, node.Addr)
+			}
+			fmt.Fprintf(&buf, "%s", address)
+			r.options.Logger.Debugf("route(retry=%d) %s", i, buf.String())
+		}
+
+		if route == nil {
+			route = DefaultRoute
+		}
+		ln, err = route.Bind(ctx, network, address, opts...)
+		if err == nil {
+			break
+		}
+		r.options.Logger.Errorf("route(retry=%d) %s", i, err)
+	}
+
+	return
+}
+
+func routePath(route chain.Route) (path []*chain.Node) {
+	if route == nil {
+		return
+	}
+	for _, node := range route.Nodes() {
+		if tr := node.Options().Transport; tr != nil {
+			path = append(path, routePath(tr.Options().Route)...)
+		}
+		path = append(path, node)
+	}
+	return
+}
+
+type packetConn struct {
+	net.Conn
+}
+
+func (c *packetConn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {
+	n, err = c.Read(b)
+	addr = c.Conn.RemoteAddr()
+	return
+}
+
+func (c *packetConn) WriteTo(b []byte, addr net.Addr) (n int, err error) {
+	return c.Write(b)
+}