content: /*
   * Copyright (C) 2011 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package android.net;
  
  import static android.content.pm.PackageManager.GET_SIGNATURES;
  
  import android.annotation.SystemService;
  import android.annotation.UnsupportedAppUsage;
  import android.app.ActivityManager;
  import android.content.Context;
  import android.content.Intent;
  import android.content.pm.PackageManager;
  import android.content.pm.PackageManager.NameNotFoundException;
  import android.content.pm.Signature;
  import android.net.wifi.WifiConfiguration;
  import android.net.wifi.WifiInfo;
  import android.os.Build;
  import android.os.RemoteException;
  import android.os.UserHandle;
  import android.telephony.SubscriptionPlan;
  import android.util.DebugUtils;
  import android.util.Pair;
  import android.util.Range;
  
  import com.google.android.collect.Sets;
  
  import java.time.ZonedDateTime;
  import java.util.HashSet;
  import java.util.Iterator;
  
  /**
   * Manager for creating and modifying network policy rules.
   *
   * {@hide}
   */
  @SystemService(Context.NETWORK_POLICY_SERVICE)
  public class NetworkPolicyManager {
  
      /* POLICY_* are masks and can be ORed, although currently they are not.*/
      /** No specific network policy, use system default. */
      public static final int POLICY_NONE = 0x0;
      /** Reject network usage on metered networks when application in background. */
      public static final int POLICY_REJECT_METERED_BACKGROUND = 0x1;
      /** Allow metered network use in the background even when in data usage save mode. */
      public static final int POLICY_ALLOW_METERED_BACKGROUND = 0x4;
  
      /*
       * Rules defining whether an uid has access to a network given its type (metered / non-metered).
       *
       * These rules are bits and can be used in bitmask operations; in particular:
       * - rule & RULE_MASK_METERED: returns the metered-networks status.
       * - rule & RULE_MASK_ALL: returns the all-networks status.
       *
       * The RULE_xxx_ALL rules applies to all networks (metered or non-metered), but on
       * metered networks, the RULE_xxx_METERED rules should be checked first. For example,
       * if the device is on Battery Saver Mode and Data Saver Mode simulatenously, and a uid
       * is whitelisted for the former but not the latter, its status would be
       * RULE_REJECT_METERED | RULE_ALLOW_ALL, meaning it could have access to non-metered
       * networks but not to metered networks.
       *
       * See network-policy-restrictions.md for more info.
       */
      /** No specific rule was set */
      public static final int RULE_NONE = 0;
      /** Allow traffic on metered networks. */
      public static final int RULE_ALLOW_METERED = 1 << 0;
      /** Temporarily allow traffic on metered networks because app is on foreground. */
      public static final int RULE_TEMPORARY_ALLOW_METERED = 1 << 1;
      /** Reject traffic on metered networks. */
      public static final int RULE_REJECT_METERED = 1 << 2;
      /** Network traffic should be allowed on all networks (metered or non-metered), although
       * metered-network restrictions could still apply. */
      public static final int RULE_ALLOW_ALL = 1 << 5;
      /** Reject traffic on all networks. */
      public static final int RULE_REJECT_ALL = 1 << 6;
      /** Mask used to get the {@code RULE_xxx_METERED} rules */
      public static final int MASK_METERED_NETWORKS = 0b00001111;
      /** Mask used to get the {@code RULE_xxx_ALL} rules */
      public static final int MASK_ALL_NETWORKS     = 0b11110000;
  
      public static final int FIREWALL_RULE_DEFAULT = 0;
  
      public static final String FIREWALL_CHAIN_NAME_NONE = "none";
      public static final String FIREWALL_CHAIN_NAME_DOZABLE = "dozable";
      public static final String FIREWALL_CHAIN_NAME_STANDBY = "standby";
      public static final String FIREWALL_CHAIN_NAME_POWERSAVE = "powersave";
  
      private static final boolean ALLOW_PLATFORM_APP_POLICY = true;
  
      public static final int FOREGROUND_THRESHOLD_STATE =
              ActivityManager.PROCESS_STATE_BOUND_FOREGROUND_SERVICE;
  
      /**
       * {@link Intent} extra that indicates which {@link NetworkTemplate} rule it
       * applies to.
       */
      public static final String EXTRA_NETWORK_TEMPLATE = "android.net.NETWORK_TEMPLATE";
  
      public static final int OVERRIDE_UNMETERED = 1 << 0;
      public static final int OVERRIDE_CONGESTED = 1 << 1;
  
      private final Context mContext;
      @UnsupportedAppUsage
      private INetworkPolicyManager mService;
  
      public NetworkPolicyManager(Context context, INetworkPolicyManager service) {
          if (service == null) {
              throw new IllegalArgumentException("missing INetworkPolicyManager");
          }
          mContext = context;
          mService = service;
      }
  
      @UnsupportedAppUsage
      public static NetworkPolicyManager from(Context context) {
          return (NetworkPolicyManager) context.getSystemService(Context.NETWORK_POLICY_SERVICE);
      }
  
      /**
       * Set policy flags for specific UID.
       *
       * @param policy should be {@link #POLICY_NONE} or any combination of {@code POLICY_} flags,
       *     although it is not validated.
       */
      @UnsupportedAppUsage
      public void setUidPolicy(int uid, int policy) {
          try {
              mService.setUidPolicy(uid, policy);
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      /**
       * Add policy flags for specific UID.
       *
       * <p>The given policy bits will be set for the uid.
       *
       * @param policy should be {@link #POLICY_NONE} or any combination of {@code POLICY_} flags,
       *     although it is not validated.
       */
      public void addUidPolicy(int uid, int policy) {
          try {
              mService.addUidPolicy(uid, policy);
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      /**
       * Clear/remove policy flags for specific UID.
       *
       * <p>The given policy bits will be set for the uid.
       *
       * @param policy should be {@link #POLICY_NONE} or any combination of {@code POLICY_} flags,
       *     although it is not validated.
       */
      public void removeUidPolicy(int uid, int policy) {
          try {
              mService.removeUidPolicy(uid, policy);
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      @UnsupportedAppUsage
      public int getUidPolicy(int uid) {
          try {
              return mService.getUidPolicy(uid);
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      @UnsupportedAppUsage
      public int[] getUidsWithPolicy(int policy) {
          try {
              return mService.getUidsWithPolicy(policy);
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
      public void registerListener(INetworkPolicyListener listener) {
          try {
              mService.registerListener(listener);
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
      public void unregisterListener(INetworkPolicyListener listener) {
          try {
              mService.unregisterListener(listener);
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      public void setNetworkPolicies(NetworkPolicy[] policies) {
          try {
              mService.setNetworkPolicies(policies);
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      @UnsupportedAppUsage
      public NetworkPolicy[] getNetworkPolicies() {
          try {
              return mService.getNetworkPolicies(mContext.getOpPackageName());
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      @UnsupportedAppUsage
      public void setRestrictBackground(boolean restrictBackground) {
          try {
              mService.setRestrictBackground(restrictBackground);
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      @UnsupportedAppUsage
      public boolean getRestrictBackground() {
          try {
              return mService.getRestrictBackground();
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      /**
       * Resets network policy settings back to factory defaults.
       *
       * @hide
       */
      public void factoryReset(String subscriber) {
          try {
              mService.factoryReset(subscriber);
          } catch (RemoteException e) {
              throw e.rethrowFromSystemServer();
          }
      }
  
      /** {@hide} */
      @Deprecated
      public static Iterator<Pair<ZonedDateTime, ZonedDateTime>> cycleIterator(NetworkPolicy policy) {
          final Iterator<Range<ZonedDateTime>> it = policy.cycleIterator();
          return new Iterator<Pair<ZonedDateTime, ZonedDateTime>>() {
              @Override
              public boolean hasNext() {
                  return it.hasNext();
              }
  
              @Override
              public Pair<ZonedDateTime, ZonedDateTime> next() {
                  if (hasNext()) {
                      final Range<ZonedDateTime> r = it.next();
                      return Pair.create(r.getLower(), r.getUpper());
                  } else {
                      return Pair.create(null, null);
                  }
              }
          };
      }
  
      /**
       * Check if given UID can have a {@link #setUidPolicy(int, int)} defined,
       * usually to protect critical system services.
       */
      @Deprecated
      public static boolean isUidValidForPolicy(Context context, int uid) {
          // first, quick-reject non-applications
          if (!UserHandle.isApp(uid)) {
              return false;
          }
  
          if (!ALLOW_PLATFORM_APP_POLICY) {
              final PackageManager pm = context.getPackageManager();
              final HashSet<Signature> systemSignature;
              try {
                  systemSignature = Sets.newHashSet(
                          pm.getPackageInfo("android", GET_SIGNATURES).signatures);
              } catch (NameNotFoundException e) {
                  throw new RuntimeException("problem finding system signature", e);
              }
  
              try {
                  // reject apps signed with platform cert
                  for (String packageName : pm.getPackagesForUid(uid)) {
                      final HashSet<Signature> packageSignature = Sets.newHashSet(
                              pm.getPackageInfo(packageName, GET_SIGNATURES).signatures);
                      if (packageSignature.containsAll(systemSignature)) {
                          return false;
                      }
                  }
              } catch (NameNotFoundException e) {
              }
          }
  
          // nothing found above; we can apply policy to UID
          return true;
      }
  
      /**
       * @hide
       */
      public static String uidRulesToString(int uidRules) {
          final StringBuilder string = new StringBuilder().append(uidRules).append(" (");
          if (uidRules == RULE_NONE) {
              string.append("NONE");
          } else {
              string.append(DebugUtils.flagsToString(NetworkPolicyManager.class, "RULE_", uidRules));
          }
          string.append(")");
          return string.toString();
      }
  
      /**
       * @hide
       */
      public static String uidPoliciesToString(int uidPolicies) {
          final StringBuilder string = new StringBuilder().append(uidPolicies).append(" (");
          if (uidPolicies == POLICY_NONE) {
              string.append("NONE");
          } else {
              string.append(DebugUtils.flagsToString(NetworkPolicyManager.class,
                      "POLICY_", uidPolicies));
          }
          string.append(")");
          return string.toString();
      }
  
      /**
       * Returns true if {@param procState} is considered foreground and as such will be allowed
       * to access network when the device is idle or in battery saver mode. Otherwise, false.
       */
      public static boolean isProcStateAllowedWhileIdleOrPowerSaveMode(int procState) {
          return procState <= FOREGROUND_THRESHOLD_STATE;
      }
  
      /**
       * Returns true if {@param procState} is considered foreground and as such will be allowed
       * to access network when the device is in data saver mode. Otherwise, false.
       */
      public static boolean isProcStateAllowedWhileOnRestrictBackground(int procState) {
          return procState <= FOREGROUND_THRESHOLD_STATE;
      }
  
      public static String resolveNetworkId(WifiConfiguration config) {
          return WifiInfo.removeDoubleQuotes(config.isPasspoint()
                  ? config.providerFriendlyName : config.SSID);
      }
  
      public static String resolveNetworkId(String ssid) {
          return WifiInfo.removeDoubleQuotes(ssid);
      }
  
      /** {@hide} */
      public static class Listener extends INetworkPolicyListener.Stub {
          @Override public void onUidRulesChanged(int uid, int uidRules) { }
          @Override public void onMeteredIfacesChanged(String[] meteredIfaces) { }
          @Override public void onRestrictBackgroundChanged(boolean restrictBackground) { }
          @Override public void onUidPoliciesChanged(int uid, int uidPolicies) { }
          @Override public void onSubscriptionOverride(int subId, int overrideMask, int overrideValue) { }
          @Override public void onSubscriptionPlansChanged(int subId, SubscriptionPlan[] plans) { }
      }
  }
  