content: /*
   * Copyright (C) 2016 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.app.admin;
  
  import android.os.Parcel;
  import android.os.Parcelable;
  
  import java.net.InetAddress;
  import java.net.UnknownHostException;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  /**
   * A class that represents a DNS lookup event initiated through the standard network stack.
   *
   * <p>It contains information about the originating app as well as the DNS hostname and resolved
   * IP addresses.
   */
  public final class DnsEvent extends NetworkEvent implements Parcelable {
  
      /** The hostname that was looked up. */
      private final String mHostname;
  
      /** Contains (possibly a subset of) the IP addresses returned. */
      private final String[] mIpAddresses;
  
      /**
       * The number of IP addresses returned from the DNS lookup event. May be different from the
       * length of ipAddresses if there were too many addresses to log.
       */
      private final int mIpAddressesCount;
  
      /** @hide */
      public DnsEvent(String hostname, String[] ipAddresses, int ipAddressesCount,
              String packageName, long timestamp) {
          super(packageName, timestamp);
          this.mHostname = hostname;
          this.mIpAddresses = ipAddresses;
          this.mIpAddressesCount = ipAddressesCount;
      }
  
      private DnsEvent(Parcel in) {
          this.mHostname = in.readString();
          this.mIpAddresses = in.createStringArray();
          this.mIpAddressesCount = in.readInt();
          this.mPackageName = in.readString();
          this.mTimestamp = in.readLong();
          this.mId = in.readLong();
      }
  
      /** Returns the hostname that was looked up. */
      public String getHostname() {
          return mHostname;
      }
  
      /** Returns (possibly a subset of) the IP addresses returned. */
      public List<InetAddress> getInetAddresses() {
          if (mIpAddresses == null || mIpAddresses.length == 0) {
              return Collections.emptyList();
          }
          final List<InetAddress> inetAddresses = new ArrayList<>(mIpAddresses.length);
          for (final String ipAddress : mIpAddresses) {
              try {
                  // ipAddress is already an address, not a host name, no DNS resolution will happen.
                  inetAddresses.add(InetAddress.getByName(ipAddress));
              } catch (UnknownHostException e) {
                  // Should never happen as we aren't passing a host name.
              }
          }
          return inetAddresses;
      }
  
      /**
       * Returns the number of IP addresses returned from the DNS lookup event. May be different from
       * the length of the list returned by {@link #getInetAddresses()} if there were too many
       * addresses to log.
       */
      public int getTotalResolvedAddressCount() {
          return mIpAddressesCount;
      }
  
      @Override
      public String toString() {
          return String.format("DnsEvent(%d, %s, %s, %d, %d, %s)", mId, mHostname,
                  (mIpAddresses == null) ? "NONE" : String.join(" ", mIpAddresses),
                  mIpAddressesCount, mTimestamp, mPackageName);
      }
  
      public static final @android.annotation.NonNull Parcelable.Creator<DnsEvent> CREATOR
              = new Parcelable.Creator<DnsEvent>() {
          @Override
          public DnsEvent createFromParcel(Parcel in) {
              if (in.readInt() != PARCEL_TOKEN_DNS_EVENT) {
                  return null;
              }
              return new DnsEvent(in);
          }
  
          @Override
          public DnsEvent[] newArray(int size) {
              return new DnsEvent[size];
          }
      };
  
      @Override
      public int describeContents() {
          return 0;
      }
  
      @Override
      public void writeToParcel(Parcel out, int flags) {
          // write parcel token first
          out.writeInt(PARCEL_TOKEN_DNS_EVENT);
          out.writeString(mHostname);
          out.writeStringArray(mIpAddresses);
          out.writeInt(mIpAddressesCount);
          out.writeString(mPackageName);
          out.writeLong(mTimestamp);
          out.writeLong(mId);
      }
  }
  