add port range support for service

internal/net/dialer/dialer.go

@@ -0,0 +1,176 @@
+package dialer
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"runtime"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/go-gost/core/logger"
+	xnet "github.com/go-gost/x/internal/net"
+	"github.com/vishvananda/netns"
+)
+
+const (
+	DefaultTimeout = 10 * time.Second
+)
+
+var (
+	DefaultNetDialer = &Dialer{}
+)
+
+type Dialer struct {
+	Interface string
+	Netns     string
+	Mark      int
+	DialFunc  func(ctx context.Context, network, addr string) (net.Conn, error)
+	Logger    logger.Logger
+}
+
+func (d *Dialer) Dial(ctx context.Context, network, addr string) (conn net.Conn, err error) {
+	if d == nil {
+		d = DefaultNetDialer
+	}
+
+	log := d.Logger
+	if log == nil {
+		log = logger.Default()
+	}
+
+	if d.Netns != "" {
+		runtime.LockOSThread()
+		defer runtime.UnlockOSThread()
+
+		originNs, err := netns.Get()
+		if err != nil {
+			return nil, fmt.Errorf("netns.Get(): %v", err)
+		}
+		defer netns.Set(originNs)
+
+		var ns netns.NsHandle
+		if strings.HasPrefix(d.Netns, "/") {
+			ns, err = netns.GetFromPath(d.Netns)
+		} else {
+			ns, err = netns.GetFromName(d.Netns)
+		}
+		if err != nil {
+			return nil, fmt.Errorf("netns.Get(%s): %v", d.Netns, err)
+		}
+		defer ns.Close()
+
+		if err := netns.Set(ns); err != nil {
+			return nil, fmt.Errorf("netns.Set(%s): %v", d.Netns, err)
+		}
+	}
+
+	if d.DialFunc != nil {
+		return d.DialFunc(ctx, network, addr)
+	}
+
+	switch network {
+	case "unix":
+		netd := net.Dialer{}
+		return netd.DialContext(ctx, network, addr)
+	default:
+	}
+
+	ifces := strings.Split(d.Interface, ",")
+	for _, ifce := range ifces {
+		strict := strings.HasSuffix(ifce, "!")
+		ifce = strings.TrimSuffix(ifce, "!")
+		var ifceName string
+		var ifAddrs []net.Addr
+		ifceName, ifAddrs, err = xnet.ParseInterfaceAddr(ifce, network)
+		if err != nil && strict {
+			return
+		}
+
+		for _, ifAddr := range ifAddrs {
+			conn, err = d.dialOnce(ctx, network, addr, ifceName, ifAddr, log)
+			if err == nil {
+				return
+			}
+
+			log.Debugf("dial %s %v@%s failed: %s", network, ifAddr, ifceName, err)
+
+			if strict &&
+				!strings.Contains(err.Error(), "no suitable address found") &&
+				!strings.Contains(err.Error(), "mismatched local address type") {
+				return
+			}
+		}
+	}
+
+	return
+}
+
+func (d *Dialer) dialOnce(ctx context.Context, network, addr, ifceName string, ifAddr net.Addr, log logger.Logger) (net.Conn, error) {
+	if ifceName != "" {
+		log.Debugf("interface: %s %v/%s", ifceName, ifAddr, network)
+	}
+
+	switch network {
+	case "udp", "udp4", "udp6":
+		if addr == "" {
+			var laddr *net.UDPAddr
+			if ifAddr != nil {
+				laddr, _ = ifAddr.(*net.UDPAddr)
+			}
+
+			c, err := net.ListenUDP(network, laddr)
+			if err != nil {
+				return nil, err
+			}
+			sc, err := c.SyscallConn()
+			if err != nil {
+				log.Error(err)
+				return nil, err
+			}
+			err = sc.Control(func(fd uintptr) {
+				if ifceName != "" {
+					if err := bindDevice(fd, ifceName); err != nil {
+						log.Warnf("bind device: %v", err)
+					}
+				}
+				if d.Mark != 0 {
+					if err := setMark(fd, d.Mark); err != nil {
+						log.Warnf("set mark: %v", err)
+					}
+				}
+			})
+			if err != nil {
+				log.Error(err)
+			}
+			return c, nil
+		}
+	case "tcp", "tcp4", "tcp6":
+	default:
+		return nil, fmt.Errorf("dial: unsupported network %s", network)
+	}
+	netd := net.Dialer{
+		LocalAddr: ifAddr,
+		Control: func(network, address string, c syscall.RawConn) error {
+			return c.Control(func(fd uintptr) {
+				if ifceName != "" {
+					if err := bindDevice(fd, ifceName); err != nil {
+						log.Warnf("bind device: %v", err)
+					}
+				}
+				if d.Mark != 0 {
+					if err := setMark(fd, d.Mark); err != nil {
+						log.Warnf("set mark: %v", err)
+					}
+				}
+			})
+		},
+	}
+	if d.Netns != "" {
+		// https://github.com/golang/go/issues/44922#issuecomment-796645858
+		netd.FallbackDelay = -1
+	}
+
+	return netd.DialContext(ctx, network, addr)
+}