Merge "Only allow System apps to make VPN exempt routes"

2 files changed, 84 insertions, 6 deletions

diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 95d146c..97b78e5 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -33,6 +33,7 @@ import static android.net.NetworkPolicyManager.RULE_ALLOW_ALL;
 import static android.net.NetworkPolicyManager.RULE_REJECT_METERED;
 
 import android.app.AlarmManager;
+import android.app.AppOpsManager;
 import android.app.Notification;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
@@ -44,7 +45,9 @@ import android.content.Context;
 import android.content.ContextWrapper;
 import android.content.Intent;
 import android.content.IntentFilter;
+import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.res.Configuration;
 import android.content.res.Resources;
 import android.database.ContentObserver;
@@ -414,6 +417,8 @@ public class ConnectivityService extends IConnectivityManager.Stub {
 
     private SettingsObserver mSettingsObserver;
 
+    private AppOpsManager mAppOpsManager;
+
     NetworkConfig[] mNetConfigs;
     int mNetworksDefined;
 
@@ -697,6 +702,8 @@ public class ConnectivityService extends IConnectivityManager.Stub {
         filter = new IntentFilter();
         filter.addAction(CONNECTED_TO_PROVISIONING_NETWORK_ACTION);
         mContext.registerReceiver(mProvisioningReceiver, filter);
+
+        mAppOpsManager = (AppOpsManager) context.getSystemService(Context.APP_OPS_SERVICE);
     }
 
     /**
@@ -1531,6 +1538,40 @@ public class ConnectivityService extends IConnectivityManager.Stub {
     }
 
     /**
+     * Check if the address falls into any of currently running VPN's route's.
+     */
+    private boolean isAddressUnderVpn(InetAddress address) {
+        synchronized (mVpns) {
+            synchronized (mRoutesLock) {
+                int uid = UserHandle.getCallingUserId();
+                Vpn vpn = mVpns.get(uid);
+                if (vpn == null) {
+                    return false;
+                }
+
+                // Check if an exemption exists for this address.
+                for (LinkAddress destination : mExemptAddresses) {
+                    if (!NetworkUtils.addressTypeMatches(address, destination.getAddress())) {
+                        continue;
+                    }
+
+                    int prefix = destination.getNetworkPrefixLength();
+                    InetAddress addrMasked = NetworkUtils.getNetworkPart(address, prefix);
+                    InetAddress destMasked = NetworkUtils.getNetworkPart(destination.getAddress(),
+                            prefix);
+
+                    if (addrMasked.equals(destMasked)) {
+                        return false;
+                    }
+                }
+
+                // Finally check if the address is covered by the VPN.
+                return vpn.isAddressCovered(address);
+            }
+        }
+    }
+
+    /**
      * @deprecated use requestRouteToHostAddress instead
      *
      * Ensure that a network route exists to deliver traffic to the specified
@@ -1566,6 +1607,34 @@ public class ConnectivityService extends IConnectivityManager.Stub {
         if (mProtectedNetworks.contains(networkType)) {
             enforceConnectivityInternalPermission();
         }
+        boolean exempt;
+        InetAddress addr;
+        try {
+            addr = InetAddress.getByAddress(hostAddress);
+        } catch (UnknownHostException e) {
+            if (DBG) log("requestRouteToHostAddress got " + e.toString());
+            return false;
+        }
+        // System apps may request routes bypassing the VPN to keep other networks working.
+        if (Binder.getCallingUid() == Process.SYSTEM_UID) {
+            exempt = true;
+        } else {
+            mAppOpsManager.checkPackage(Binder.getCallingUid(), packageName);
+            try {
+                ApplicationInfo info = mContext.getPackageManager().getApplicationInfo(packageName,
+                        0);
+                exempt = (info.flags & ApplicationInfo.FLAG_SYSTEM) != 0;
+            } catch (NameNotFoundException e) {
+                throw new IllegalArgumentException("Failed to find calling package details", e);
+            }
+        }
+
+        // Non-exempt routeToHost's can only be added if the host is not covered by the VPN.
+        // This can be either because the VPN's routes do not cover the destination or a
+        // system application added an exemption that covers this destination.
+        if (!exempt && isAddressUnderVpn(addr)) {
+            return false;
+        }
 
         if (!ConnectivityManager.isNetworkTypeValid(networkType)) {
             if (DBG) log("requestRouteToHostAddress on invalid network: " + networkType);
@@ -1592,18 +1661,13 @@ public class ConnectivityService extends IConnectivityManager.Stub {
         }
         final long token = Binder.clearCallingIdentity();
         try {
-            InetAddress addr = InetAddress.getByAddress(hostAddress);
             LinkProperties lp = tracker.getLinkProperties();
-            boolean ok = addRouteToAddress(lp, addr, EXEMPT);
+            boolean ok = addRouteToAddress(lp, addr, exempt);
             if (DBG) log("requestRouteToHostAddress ok=" + ok);
             return ok;
-        } catch (UnknownHostException e) {
-            if (DBG) log("requestRouteToHostAddress got " + e.toString());
         } finally {
             Binder.restoreCallingIdentity(token);
         }
-        if (DBG) log("requestRouteToHostAddress X bottom return false");
-        return false;
     }
 
     private boolean addRoute(LinkProperties p, RouteInfo r, boolean toDefaultTable,
diff --git a/services/core/java/com/android/server/connectivity/Vpn.java b/services/core/java/com/android/server/connectivity/Vpn.java
index d87387f..af08d57 100644
--- a/services/core/java/com/android/server/connectivity/Vpn.java
+++ b/services/core/java/com/android/server/connectivity/Vpn.java
@@ -44,6 +44,7 @@ import android.net.LinkProperties;
 import android.net.LocalSocket;
 import android.net.LocalSocketAddress;
 import android.net.NetworkInfo;
+import android.net.NetworkUtils;
 import android.net.RouteInfo;
 import android.net.NetworkInfo.DetailedState;
 import android.os.Binder;
@@ -74,6 +75,7 @@ import com.android.server.net.BaseNetworkObserver;
 import java.io.File;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.net.InetAddress;
 import java.net.Inet4Address;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
@@ -430,6 +432,18 @@ public class Vpn extends BaseNetworkStateTracker {
         return tun;
     }
 
+    /**
+     * Check if a given address is covered by the VPN's routing rules.
+     */
+    public boolean isAddressCovered(InetAddress address) {
+        synchronized (Vpn.this) {
+            if (!isRunningLocked()) {
+                return false;
+            }
+            return RouteInfo.selectBestRoute(mConfig.routes, address) != null;
+        }
+    }
+
     private boolean isRunningLocked() {
         return mVpnUsers != null;
     }