Merge "Always give VPN the INTERNET capability."

services/core/java/com/android/server/connectivity/Vpn.java

@@ -953,30 +953,21 @@ public class Vpn {
             return false;
         }
 
-        LinkProperties lp = makeLinkProperties();
+        agent.sendLinkProperties(makeLinkProperties());
-        final boolean hadInternetCapability = mNetworkCapabilities.hasCapability(
-                NetworkCapabilities.NET_CAPABILITY_INTERNET);
-        final boolean willHaveInternetCapability = providesRoutesToMostDestinations(lp);
-        if (hadInternetCapability != willHaveInternetCapability) {
-            // A seamless handover would have led to a change to INTERNET capability, which
-            // is supposed to be immutable for a given network. In this case bail out and do not
-            // perform handover.
-            Log.i(TAG, "Handover not possible due to changes to INTERNET capability");
-            return false;
-        }
-
-        agent.sendLinkProperties(lp);
         return true;
     }
 
     private void agentConnect() {
         LinkProperties lp = makeLinkProperties();
 
-        if (providesRoutesToMostDestinations(lp)) {
+        // VPN either provide a default route (IPv4 or IPv6 or both), or they are a split tunnel
+        // that falls back to the default network, which by definition provides INTERNET (unless
+        // there is no default network, in which case none of this matters in any sense).
+        // Also, it guarantees that when a VPN applies to an app, the VPN will always be reported
+        // as the network by getDefaultNetwork and registerDefaultNetworkCallback. This in turn
+        // protects the invariant that apps calling CM#bindProcessToNetwork(getDefaultNetwork())
+        // the same as if they use the default network.
         mNetworkCapabilities.addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET);
-        } else {
-            mNetworkCapabilities.removeCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET);
-        }
 
         mNetworkInfo.setDetailedState(DetailedState.CONNECTING, null, null);
 

tests/net/java/com/android/server/connectivity/VpnTest.java

@@ -727,94 +727,4 @@ public class VpnTest {
                 "::/1", "8000::/2", "c000::/3", "e000::/4", "f000::/5", "f800::/6",
                 "fe00::/8", "2605:ef80:e:af1d::/64");
     }
-
-    @Test
-    public void testProvidesRoutesToMostDestinations() {
-        final LinkProperties lp = new LinkProperties();
-
-        // Default route provides routes to all IPv4 destinations.
-        lp.addRoute(new RouteInfo(new IpPrefix("0.0.0.0/0")));
-        assertTrue(Vpn.providesRoutesToMostDestinations(lp));
-
-        // Empty LP provides routes to no destination
-        lp.clear();
-        assertFalse(Vpn.providesRoutesToMostDestinations(lp));
-
-        // All IPv4 routes except for local networks. This is the case most relevant
-        // to this function. It provides routes to almost the entire space.
-        // (clone the stream so that we can reuse it later)
-        publicIpV4Routes().forEach(s -> lp.addRoute(new RouteInfo(new IpPrefix(s))));
-        assertTrue(Vpn.providesRoutesToMostDestinations(lp));
-
-        // Removing a 16-bit prefix, which is 65536 addresses. This is still enough to
-        // provide routes to "most" destinations.
-        lp.removeRoute(new RouteInfo(new IpPrefix("192.169.0.0/16")));
-        assertTrue(Vpn.providesRoutesToMostDestinations(lp));
-
-        // Remove the /2 route, which represent a quarter of the available routing space.
-        // This LP does not provides routes to "most" destinations any more.
-        lp.removeRoute(new RouteInfo(new IpPrefix("64.0.0.0/2")));
-        assertFalse(Vpn.providesRoutesToMostDestinations(lp));
-
-        lp.clear();
-        publicIpV6Routes().forEach(s -> lp.addRoute(new RouteInfo(new IpPrefix(s))));
-        assertTrue(Vpn.providesRoutesToMostDestinations(lp));
-
-        lp.removeRoute(new RouteInfo(new IpPrefix("::/1")));
-        assertFalse(Vpn.providesRoutesToMostDestinations(lp));
-
-        // V6 does not provide sufficient coverage but v4 does
-        publicIpV4Routes().forEach(s -> lp.addRoute(new RouteInfo(new IpPrefix(s))));
-        assertTrue(Vpn.providesRoutesToMostDestinations(lp));
-
-        // V4 still does
-        lp.removeRoute(new RouteInfo(new IpPrefix("192.169.0.0/16")));
-        assertTrue(Vpn.providesRoutesToMostDestinations(lp));
-
-        // V4 does not any more
-        lp.removeRoute(new RouteInfo(new IpPrefix("64.0.0.0/2")));
-        assertFalse(Vpn.providesRoutesToMostDestinations(lp));
-
-        // V4 does not, but V6 has sufficient coverage again
-        lp.addRoute(new RouteInfo(new IpPrefix("::/1")));
-        assertTrue(Vpn.providesRoutesToMostDestinations(lp));
-
-        lp.clear();
-        // V4-unreachable route should not be treated as sufficient coverage
-        lp.addRoute(new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), RTN_UNREACHABLE));
-        assertFalse(Vpn.providesRoutesToMostDestinations(lp));
-
-        lp.clear();
-        // V6-unreachable route should not be treated as sufficient coverage
-        lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), RTN_UNREACHABLE));
-        assertFalse(Vpn.providesRoutesToMostDestinations(lp));
-    }
-
-    @Test
-    public void testDoesNotLockUpWithTooManyRoutes() {
-        final LinkProperties lp = new LinkProperties();
-        final byte[] ad = new byte[4];
-        // Actually evaluating this many routes under 1500ms is impossible on
-        // current hardware and for some time, as the algorithm is O(n²).
-        // Make sure the system has a safeguard against this and does not
-        // lock up.
-        final int MAX_ROUTES = 4000;
-        final long MAX_ALLOWED_TIME_MS = 1500;
-        for (int i = 0; i < MAX_ROUTES; ++i) {
-            ad[0] = (byte)((i >> 24) & 0xFF);
-            ad[1] = (byte)((i >> 16) & 0xFF);
-            ad[2] = (byte)((i >> 8) & 0xFF);
-            ad[3] = (byte)(i & 0xFF);
-            try {
-                lp.addRoute(new RouteInfo(new IpPrefix(Inet4Address.getByAddress(ad), 32)));
-            } catch (UnknownHostException e) {
-                // UnknownHostException is only thrown for an address of illegal length,
-                // which can't happen in the case above.
-            }
-        }
-        final long start = SystemClock.currentThreadTimeMillis();
-        assertTrue(Vpn.providesRoutesToMostDestinations(lp));
-        final long end = SystemClock.currentThreadTimeMillis();
-        assertTrue(end - start < MAX_ALLOWED_TIME_MS);
-    }
 }