Slightly refactor IPv4 default router interface selection
Test: as follows
- built
- flashed
- booted
- USB tethering to dualstack wifi yields log lines like:
14:33:31.970 - Looking for default routes on: {InterfaceName: wlan0 ...
14:33:31.970 - IPv4/IPv6 upstream interface(s): wlan0/null
and working tethering
- runtest frameworks-net passes
Bug: 64380515
Bug: 64382985
Bug: 64976379
Change-Id: Iac94d870653ae1b71df00e8179cc4ecdb7ac412f
diff --git a/services/core/java/com/android/server/connectivity/Tethering.java b/services/core/java/com/android/server/connectivity/Tethering.java
index 69dec2d..1767a21 100644
--- a/services/core/java/com/android/server/connectivity/Tethering.java
+++ b/services/core/java/com/android/server/connectivity/Tethering.java
@@ -19,6 +19,7 @@
import static android.hardware.usb.UsbManager.USB_CONFIGURED;
import static android.hardware.usb.UsbManager.USB_CONNECTED;
import static android.hardware.usb.UsbManager.USB_FUNCTION_RNDIS;
+import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
import static android.net.wifi.WifiManager.EXTRA_WIFI_AP_INTERFACE_NAME;
import static android.net.wifi.WifiManager.EXTRA_WIFI_AP_MODE;
import static android.net.wifi.WifiManager.EXTRA_WIFI_AP_STATE;
@@ -99,6 +100,7 @@
import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.net.Inet4Address;
+import java.net.Inet6Address;
import java.net.InetAddress;
import java.util.ArrayList;
import java.util.Arrays;
@@ -1302,19 +1304,16 @@
protected void setUpstreamNetwork(NetworkState ns) {
String iface = null;
- if (ns != null && ns.linkProperties != null) {
+ if (ns != null) {
// Find the interface with the default IPv4 route. It may be the
// interface described by linkProperties, or one of the interfaces
// stacked on top of it.
- mLog.i("Finding IPv4 upstream interface on: " + ns.linkProperties);
- RouteInfo ipv4Default = RouteInfo.selectBestRoute(
- ns.linkProperties.getAllRoutes(), Inet4Address.ANY);
- if (ipv4Default != null) {
- iface = ipv4Default.getInterface();
- mLog.i("Found interface " + ipv4Default.getInterface());
- } else {
- mLog.i("No IPv4 upstream interface, giving up.");
- }
+ mLog.i("Looking for default routes on: " + ns.linkProperties);
+ final String iface4 = getIPv4DefaultRouteInterface(ns);
+ final String iface6 = getIPv6DefaultRouteInterface(ns);
+ mLog.i("IPv4/IPv6 upstream interface(s): " + iface4 + "/" + iface6);
+
+ iface = (iface4 != null) ? iface4 : null /* TODO: iface6 */;
}
if (iface != null) {
@@ -1957,6 +1956,31 @@
mTetherStates.remove(iface);
}
+ private static String getIPv4DefaultRouteInterface(NetworkState ns) {
+ if (ns == null) return null;
+ return getInterfaceForDestination(ns.linkProperties, Inet4Address.ANY);
+ }
+
+ private static String getIPv6DefaultRouteInterface(NetworkState ns) {
+ if (ns == null) return null;
+ // An upstream network's IPv6 capability is currently only useful if it
+ // can be 64share'd downstream (RFC 7278). For now, that means mobile
+ // upstream networks only.
+ if (ns.networkCapabilities == null ||
+ !ns.networkCapabilities.hasTransport(TRANSPORT_CELLULAR)) {
+ return null;
+ }
+
+ return getInterfaceForDestination(ns.linkProperties, Inet6Address.ANY);
+ }
+
+ private static String getInterfaceForDestination(LinkProperties lp, InetAddress dst) {
+ final RouteInfo ri = (lp != null)
+ ? RouteInfo.selectBestRoute(lp.getAllRoutes(), dst)
+ : null;
+ return (ri != null) ? ri.getInterface() : null;
+ }
+
private static String[] copy(String[] strarray) {
return Arrays.copyOf(strarray, strarray.length);
}