init

tuntap_linux.go

@@ -0,0 +1,173 @@
+package gost
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"syscall"
+
+	"github.com/docker/libcontainer/netlink"
+	"github.com/go-log/log"
+	"github.com/milosgajdos/tenus"
+	"github.com/songgao/water"
+)
+
+func createTun(cfg TunConfig) (conn net.Conn, itf *net.Interface, err error) {
+	ip, ipNet, err := net.ParseCIDR(cfg.Addr)
+	if err != nil {
+		return
+	}
+
+	ifce, err := water.New(water.Config{
+		DeviceType: water.TUN,
+		PlatformSpecificParams: water.PlatformSpecificParams{
+			Name: cfg.Name,
+		},
+	})
+	if err != nil {
+		return
+	}
+
+	link, err := tenus.NewLinkFrom(ifce.Name())
+	if err != nil {
+		return
+	}
+
+	mtu := cfg.MTU
+	if mtu <= 0 {
+		mtu = DefaultMTU
+	}
+
+	cmd := fmt.Sprintf("ip link set dev %s mtu %d", ifce.Name(), mtu)
+	log.Log("[tun]", cmd)
+	if er := link.SetLinkMTU(mtu); er != nil {
+		err = fmt.Errorf("%s: %v", cmd, er)
+		return
+	}
+
+	cmd = fmt.Sprintf("ip address add %s dev %s", cfg.Addr, ifce.Name())
+	log.Log("[tun]", cmd)
+	if er := link.SetLinkIp(ip, ipNet); er != nil {
+		err = fmt.Errorf("%s: %v", cmd, er)
+		return
+	}
+
+	cmd = fmt.Sprintf("ip link set dev %s up", ifce.Name())
+	log.Log("[tun]", cmd)
+	if er := link.SetLinkUp(); er != nil {
+		err = fmt.Errorf("%s: %v", cmd, er)
+		return
+	}
+
+	if err = addTunRoutes(ifce.Name(), cfg.Routes...); err != nil {
+		return
+	}
+
+	itf, err = net.InterfaceByName(ifce.Name())
+	if err != nil {
+		return
+	}
+
+	conn = &tunTapConn{
+		ifce: ifce,
+		addr: &net.IPAddr{IP: ip},
+	}
+	return
+}
+
+func createTap(cfg TapConfig) (conn net.Conn, itf *net.Interface, err error) {
+	var ip net.IP
+	var ipNet *net.IPNet
+	if cfg.Addr != "" {
+		ip, ipNet, err = net.ParseCIDR(cfg.Addr)
+		if err != nil {
+			return
+		}
+	}
+
+	ifce, err := water.New(water.Config{
+		DeviceType: water.TAP,
+		PlatformSpecificParams: water.PlatformSpecificParams{
+			Name: cfg.Name,
+		},
+	})
+	if err != nil {
+		return
+	}
+
+	link, err := tenus.NewLinkFrom(ifce.Name())
+	if err != nil {
+		return
+	}
+
+	mtu := cfg.MTU
+	if mtu <= 0 {
+		mtu = DefaultMTU
+	}
+
+	cmd := fmt.Sprintf("ip link set dev %s mtu %d", ifce.Name(), mtu)
+	log.Log("[tap]", cmd)
+	if er := link.SetLinkMTU(mtu); er != nil {
+		err = fmt.Errorf("%s: %v", cmd, er)
+		return
+	}
+
+	if cfg.Addr != "" {
+		cmd = fmt.Sprintf("ip address add %s dev %s", cfg.Addr, ifce.Name())
+		log.Log("[tap]", cmd)
+		if er := link.SetLinkIp(ip, ipNet); er != nil {
+			err = fmt.Errorf("%s: %v", cmd, er)
+			return
+		}
+	}
+
+	cmd = fmt.Sprintf("ip link set dev %s up", ifce.Name())
+	log.Log("[tap]", cmd)
+	if er := link.SetLinkUp(); er != nil {
+		err = fmt.Errorf("%s: %v", cmd, er)
+		return
+	}
+
+	if err = addTapRoutes(ifce.Name(), cfg.Gateway, cfg.Routes...); err != nil {
+		return
+	}
+
+	itf, err = net.InterfaceByName(ifce.Name())
+	if err != nil {
+		return
+	}
+
+	conn = &tunTapConn{
+		ifce: ifce,
+		addr: &net.IPAddr{IP: ip},
+	}
+	return
+}
+
+func addTunRoutes(ifName string, routes ...IPRoute) error {
+	for _, route := range routes {
+		if route.Dest == nil {
+			continue
+		}
+		cmd := fmt.Sprintf("ip route add %s dev %s", route.Dest.String(), ifName)
+		log.Logf("[tun] %s", cmd)
+		if err := netlink.AddRoute(route.Dest.String(), "", "", ifName); err != nil && !errors.Is(err, syscall.EEXIST) {
+			return fmt.Errorf("%s: %v", cmd, err)
+		}
+	}
+	return nil
+}
+
+func addTapRoutes(ifName string, gw string, routes ...string) error {
+	for _, route := range routes {
+		if route == "" {
+			continue
+		}
+		cmd := fmt.Sprintf("ip route add %s via %s dev %s", route, gw, ifName)
+		log.Logf("[tap] %s", cmd)
+		if err := netlink.AddRoute(route, "", gw, ifName); err != nil {
+			return fmt.Errorf("%s: %v", cmd, err)
+		}
+	}
+	return nil
+}