Mobile (#735)

Initial modification to support mobile client

Export necessary interfaces for Android framework

iface/tun_linux.go

@@ -0,0 +1,148 @@
+//go:build linux && !android
+
+package iface
+
+import (
+	"fmt"
+	"os"
+
+	log "github.com/sirupsen/logrus"
+	"github.com/vishvananda/netlink"
+)
+
+func (c *tunDevice) Create() error {
+	if WireguardModuleIsLoaded() {
+		log.Info("using kernel WireGuard")
+		return c.createWithKernel()
+	}
+
+	if !tunModuleIsLoaded() {
+		return fmt.Errorf("couldn't check or load tun module")
+	}
+	log.Info("using userspace WireGuard")
+	var err error
+	c.netInterface, err = c.createWithUserspace()
+	if err != nil {
+		return err
+	}
+
+	return c.assignAddr()
+
+}
+
+// createWithKernel Creates a new Wireguard interface using kernel Wireguard module.
+// Works for Linux and offers much better network performance
+func (c *tunDevice) createWithKernel() error {
+
+	link := newWGLink(c.name)
+
+	// check if interface exists
+	l, err := netlink.LinkByName(c.name)
+	if err != nil {
+		switch err.(type) {
+		case netlink.LinkNotFoundError:
+			break
+		default:
+			return err
+		}
+	}
+
+	// remove if interface exists
+	if l != nil {
+		err = netlink.LinkDel(link)
+		if err != nil {
+			return err
+		}
+	}
+
+	log.Debugf("adding device: %s", c.name)
+	err = netlink.LinkAdd(link)
+	if os.IsExist(err) {
+		log.Infof("interface %s already exists. Will reuse.", c.name)
+	} else if err != nil {
+		return err
+	}
+
+	c.netInterface = link
+
+	err = c.assignAddr()
+	if err != nil {
+		return err
+	}
+
+	// todo do a discovery
+	log.Debugf("setting MTU: %d interface: %s", c.mtu, c.name)
+	err = netlink.LinkSetMTU(link, c.mtu)
+	if err != nil {
+		log.Errorf("error setting MTU on interface: %s", c.name)
+		return err
+	}
+
+	log.Debugf("bringing up interface: %s", c.name)
+	err = netlink.LinkSetUp(link)
+	if err != nil {
+		log.Errorf("error bringing up interface: %s", c.name)
+		return err
+	}
+
+	return nil
+}
+
+// assignAddr Adds IP address to the tunnel interface
+func (c *tunDevice) assignAddr() error {
+	link := newWGLink(c.name)
+
+	//delete existing addresses
+	list, err := netlink.AddrList(link, 0)
+	if err != nil {
+		return err
+	}
+	if len(list) > 0 {
+		for _, a := range list {
+			err = netlink.AddrDel(link, &a)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	log.Debugf("adding address %s to interface: %s", c.address.String(), c.name)
+	addr, _ := netlink.ParseAddr(c.address.String())
+	err = netlink.AddrAdd(link, addr)
+	if os.IsExist(err) {
+		log.Infof("interface %s already has the address: %s", c.name, c.address.String())
+	} else if err != nil {
+		return err
+	}
+	// On linux, the link must be brought up
+	err = netlink.LinkSetUp(link)
+	return err
+}
+
+type wgLink struct {
+	attrs *netlink.LinkAttrs
+}
+
+func newWGLink(name string) *wgLink {
+	attrs := netlink.NewLinkAttrs()
+	attrs.Name = name
+
+	return &wgLink{
+		attrs: &attrs,
+	}
+}
+
+// Attrs returns the Wireguard's default attributes
+func (l *wgLink) Attrs() *netlink.LinkAttrs {
+	return l.attrs
+}
+
+// Type returns the interface type
+func (l *wgLink) Type() string {
+	return "wireguard"
+}
+
+// Close deletes the link interface
+func (l *wgLink) Close() error {
+	return netlink.LinkDel(l)
+}