android/net/LinkAddress.java - platform/prebuilts/fullsdk/sources/android-30 - Git at Google

 /*
  * Copyright (C) 2010 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.system.OsConstants.IFA_F_DADFAILED;
 import static android.system.OsConstants.IFA_F_DEPRECATED;
 import static android.system.OsConstants.IFA_F_OPTIMISTIC;
 import static android.system.OsConstants.IFA_F_PERMANENT;
 import static android.system.OsConstants.IFA_F_TENTATIVE;
 import static android.system.OsConstants.RT_SCOPE_HOST;
 import static android.system.OsConstants.RT_SCOPE_LINK;
 import static android.system.OsConstants.RT_SCOPE_SITE;
 import static android.system.OsConstants.RT_SCOPE_UNIVERSE;

 import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.os.Build;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.os.SystemClock;
 import android.util.Pair;

 import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.net.InterfaceAddress;
 import java.net.UnknownHostException;
 import java.util.Objects;

 /**
  * Identifies an IP address on a network link.
  *
  * A {@code LinkAddress} consists of:
  * <ul>
  * <li>An IP address and prefix length (e.g., {@code 2001:db8::1/64} or {@code 192.0.2.1/24}).
  * The address must be unicast, as multicast addresses cannot be assigned to interfaces.
  * <li>Address flags: A bitmask of {@code OsConstants.IFA_F_*} values representing properties
  * of the address (e.g., {@code android.system.OsConstants.IFA_F_OPTIMISTIC}).
  * <li>Address scope: One of the {@code OsConstants.IFA_F_*} values; defines the scope in which
  * the address is unique (e.g.,
  * {@code android.system.OsConstants.RT_SCOPE_LINK} or
  * {@code android.system.OsConstants.RT_SCOPE_UNIVERSE}).
  * </ul>
  */
 public class LinkAddress implements Parcelable {

     /**
      * Indicates the deprecation or expiration time is unknown
      * @hide
      */
     @SystemApi
     public static final long LIFETIME_UNKNOWN = -1;

     /**
      * Indicates this address is permanent.
      * @hide
      */
     @SystemApi
     public static final long LIFETIME_PERMANENT = Long.MAX_VALUE;

     /**
      * IPv4 or IPv6 address.
      */
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
     private InetAddress address;

     /**
      * Prefix length.
      */
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
     private int prefixLength;

     /**
      * Address flags. A bitmask of {@code IFA_F_*} values. Note that {@link #getFlags()} may not
      * return these exact values. For example, it may set or clear the {@code IFA_F_DEPRECATED}
      * flag depending on the current preferred lifetime.
      */
     private int flags;

     /**
      * Address scope. One of the RT_SCOPE_* constants.
      */
     private int scope;

     /**
      * The time, as reported by {@link SystemClock#elapsedRealtime}, when this LinkAddress will be
      * or was deprecated. At the time existing connections can still use this address until it
      * expires, but new connections should use the new address. {@link #LIFETIME_UNKNOWN} indicates
      * this information is not available. {@link #LIFETIME_PERMANENT} indicates this
      * {@link LinkAddress} will never be deprecated.
      */
     private long deprecationTime;

     /**
      * The time, as reported by {@link SystemClock#elapsedRealtime}, when this {@link LinkAddress}
      * will expire and be removed from the interface. {@link #LIFETIME_UNKNOWN} indicates this
      * information is not available. {@link #LIFETIME_PERMANENT} indicates this {@link LinkAddress}
      * will never expire.
      */
     private long expirationTime;

     /**
      * Utility function to determines the scope of a unicast address. Per RFC 4291 section 2.5 and
      * RFC 6724 section 3.2.
      * @hide
      */
     private static int scopeForUnicastAddress(InetAddress addr) {
         if (addr.isAnyLocalAddress()) {
             return RT_SCOPE_HOST;
         }

         if (addr.isLoopbackAddress() || addr.isLinkLocalAddress()) {
             return RT_SCOPE_LINK;
         }

         // isSiteLocalAddress() returns true for private IPv4 addresses, but RFC 6724 section 3.2
         // says that they are assigned global scope.
         if (!(addr instanceof Inet4Address) && addr.isSiteLocalAddress()) {
             return RT_SCOPE_SITE;
         }

         return RT_SCOPE_UNIVERSE;
     }

     /**
      * Utility function to check if |address| is a Unique Local IPv6 Unicast Address
      * (a.k.a. "ULA"; RFC 4193).
      *
      * Per RFC 4193 section 8, fc00::/7 identifies these addresses.
      */
     private boolean isIpv6ULA() {
         if (isIpv6()) {
             byte[] bytes = address.getAddress();
             return ((bytes[0] & (byte)0xfe) == (byte)0xfc);
         }
         return false;
     }

     /**
      * @return true if the address is IPv6.
      * @hide
      */
     @TestApi
     @SystemApi
     public boolean isIpv6() {
         return address instanceof Inet6Address;
     }

     /**
      * For backward compatibility.
      * This was annotated with @UnsupportedAppUsage in P, so we can't remove the method completely
      * just yet.
      * @return true if the address is IPv6.
      * @hide
      */
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
     public boolean isIPv6() {
         return isIpv6();
     }

     /**
      * @return true if the address is IPv4 or is a mapped IPv4 address.
      * @hide
      */
     @TestApi
     @SystemApi
     public boolean isIpv4() {
         return address instanceof Inet4Address;
     }

     /**
      * Utility function for the constructors.
      */
     private void init(InetAddress address, int prefixLength, int flags, int scope,
                       long deprecationTime, long expirationTime) {
         if (address == null ||
                 address.isMulticastAddress() ||
                 prefixLength < 0 ||
                 (address instanceof Inet4Address && prefixLength > 32) ||
                 (prefixLength > 128)) {
             throw new IllegalArgumentException("Bad LinkAddress params " + address +
                     "/" + prefixLength);
         }

         // deprecation time and expiration time must be both provided, or neither.
         if ((deprecationTime == LIFETIME_UNKNOWN) != (expirationTime == LIFETIME_UNKNOWN)) {
             throw new IllegalArgumentException(
                     "Must not specify only one of deprecation time and expiration time");
         }

         // deprecation time needs to be a positive value.
         if (deprecationTime != LIFETIME_UNKNOWN && deprecationTime < 0) {
             throw new IllegalArgumentException("invalid deprecation time " + deprecationTime);
         }

         // expiration time needs to be a positive value.
         if (expirationTime != LIFETIME_UNKNOWN && expirationTime < 0) {
             throw new IllegalArgumentException("invalid expiration time " + expirationTime);
         }

         // expiration time can't be earlier than deprecation time
         if (deprecationTime != LIFETIME_UNKNOWN && expirationTime != LIFETIME_UNKNOWN
                 && expirationTime < deprecationTime) {
             throw new IllegalArgumentException("expiration earlier than deprecation ("
                     + deprecationTime + ", " + expirationTime + ")");
         }

         this.address = address;
         this.prefixLength = prefixLength;
         this.flags = flags;
         this.scope = scope;
         this.deprecationTime = deprecationTime;
         this.expirationTime = expirationTime;
     }

     /**
      * Constructs a new {@code LinkAddress} from an {@code InetAddress} and prefix length, with
      * the specified flags and scope. Flags and scope are not checked for validity.
      *
      * @param address The IP address.
      * @param prefixLength The prefix length. Must be &gt;= 0 and &lt;= (32 or 128) (IPv4 or IPv6).
      * @param flags A bitmask of {@code IFA_F_*} values representing properties of the address.
      * @param scope An integer defining the scope in which the address is unique (e.g.,
      *              {@link OsConstants#RT_SCOPE_LINK} or {@link OsConstants#RT_SCOPE_SITE}).
      * @hide
      */
     @SystemApi
     @TestApi
     public LinkAddress(@NonNull InetAddress address, @IntRange(from = 0, to = 128) int prefixLength,
             int flags, int scope) {
         init(address, prefixLength, flags, scope, LIFETIME_UNKNOWN, LIFETIME_UNKNOWN);
     }

     /**
      * Constructs a new {@code LinkAddress} from an {@code InetAddress}, prefix length, with
      * the specified flags, scope, deprecation time, and expiration time. Flags and scope are not
      * checked for validity. The value of the {@code IFA_F_DEPRECATED} and {@code IFA_F_PERMANENT}
      * flag will be adjusted based on the passed-in lifetimes.
      *
      * @param address The IP address.
      * @param prefixLength The prefix length. Must be &gt;= 0 and &lt;= (32 or 128) (IPv4 or IPv6).
      * @param flags A bitmask of {@code IFA_F_*} values representing properties of the address.
      * @param scope An integer defining the scope in which the address is unique (e.g.,
      *              {@link OsConstants#RT_SCOPE_LINK} or {@link OsConstants#RT_SCOPE_SITE}).
      * @param deprecationTime The time, as reported by {@link SystemClock#elapsedRealtime}, when
      *                        this {@link LinkAddress} will be or was deprecated. At the time
      *                        existing connections can still use this address until it expires, but
      *                        new connections should use the new address. {@link #LIFETIME_UNKNOWN}
      *                        indicates this information is not available.
      *                        {@link #LIFETIME_PERMANENT} indicates this {@link LinkAddress} will
      *                        never be deprecated.
      * @param expirationTime The time, as reported by {@link SystemClock#elapsedRealtime}, when this
      *                       {@link LinkAddress} will expire and be removed from the interface.
      *                       {@link #LIFETIME_UNKNOWN} indicates this information is not available.
      *                       {@link #LIFETIME_PERMANENT} indicates this {@link LinkAddress} will
      *                       never expire.
      * @hide
      */
     @SystemApi
     @TestApi
     public LinkAddress(@NonNull InetAddress address, @IntRange(from = 0, to = 128) int prefixLength,
                        int flags, int scope, long deprecationTime, long expirationTime) {
         init(address, prefixLength, flags, scope, deprecationTime, expirationTime);
     }

     /**
      * Constructs a new {@code LinkAddress} from an {@code InetAddress} and a prefix length.
      * The flags are set to zero and the scope is determined from the address.
      * @param address The IP address.
      * @param prefixLength The prefix length. Must be &gt;= 0 and &lt;= (32 or 128) (IPv4 or IPv6).
      * @hide
      */
     @SystemApi
     @TestApi
     public LinkAddress(@NonNull InetAddress address,
             @IntRange(from = 0, to = 128) int prefixLength) {
         this(address, prefixLength, 0, 0);
         this.scope = scopeForUnicastAddress(address);
     }

     /**
      * Constructs a new {@code LinkAddress} from an {@code InterfaceAddress}.
      * The flags are set to zero and the scope is determined from the address.
      * @param interfaceAddress The interface address.
      * @hide
      */
     public LinkAddress(@NonNull InterfaceAddress interfaceAddress) {
         this(interfaceAddress.getAddress(),
              interfaceAddress.getNetworkPrefixLength());
     }

     /**
      * Constructs a new {@code LinkAddress} from a string such as "192.0.2.5/24" or
      * "2001:db8::1/64". The flags are set to zero and the scope is determined from the address.
      * @param address The string to parse.
      * @hide
      */
     @SystemApi
     @TestApi
     public LinkAddress(@NonNull String address) {
         this(address, 0, 0);
         this.scope = scopeForUnicastAddress(this.address);
     }

     /**
      * Constructs a new {@code LinkAddress} from a string such as "192.0.2.5/24" or
      * "2001:db8::1/64", with the specified flags and scope.
      * @param address The string to parse.
      * @param flags The address flags.
      * @param scope The address scope.
      * @hide
      */
     @SystemApi
     @TestApi
     public LinkAddress(@NonNull String address, int flags, int scope) {
         // This may throw an IllegalArgumentException; catching it is the caller's responsibility.
         // TODO: consider rejecting mapped IPv4 addresses such as "::ffff:192.0.2.5/24".
         Pair<InetAddress, Integer> ipAndMask = NetworkUtils.parseIpAndMask(address);
         init(ipAndMask.first, ipAndMask.second, flags, scope, LIFETIME_UNKNOWN, LIFETIME_UNKNOWN);
     }

     /**
      * Returns a string representation of this address, such as "192.0.2.1/24" or "2001:db8::1/64".
      * The string representation does not contain the flags and scope, just the address and prefix
      * length.
      */
     @Override
     public String toString() {
         return address.getHostAddress() + "/" + prefixLength;
     }

     /**
      * Compares this {@code LinkAddress} instance against {@code obj}. Two addresses are equal if
      * their address, prefix length, flags and scope are equal. Thus, for example, two addresses
      * that have the same address and prefix length are not equal if one of them is deprecated and
      * the other is not.
      *
      * @param obj the object to be tested for equality.
      * @return {@code true} if both objects are equal, {@code false} otherwise.
      */
     @Override
     public boolean equals(Object obj) {
         if (!(obj instanceof LinkAddress)) {
             return false;
         }
         LinkAddress linkAddress = (LinkAddress) obj;
         return this.address.equals(linkAddress.address)
                 && this.prefixLength == linkAddress.prefixLength
                 && this.flags == linkAddress.flags
                 && this.scope == linkAddress.scope
                 && this.deprecationTime == linkAddress.deprecationTime
                 && this.expirationTime == linkAddress.expirationTime;
     }

     /**
      * Returns a hashcode for this address.
      */
     @Override
     public int hashCode() {
         return Objects.hash(address, prefixLength, flags, scope, deprecationTime, expirationTime);
     }

     /**
      * Determines whether this {@code LinkAddress} and the provided {@code LinkAddress}
      * represent the same address. Two {@code LinkAddresses} represent the same address
      * if they have the same IP address and prefix length, even if their properties are
      * different.
      *
      * @param other the {@code LinkAddress} to compare to.
      * @return {@code true} if both objects have the same address and prefix length, {@code false}
      * otherwise.
      * @hide
      */
     @TestApi
     @SystemApi
     public boolean isSameAddressAs(@Nullable LinkAddress other) {
         if (other == null) {
             return false;
         }
         return address.equals(other.address) && prefixLength == other.prefixLength;
     }

     /**
      * Returns the {@link InetAddress} of this {@code LinkAddress}.
      */
     public InetAddress getAddress() {
         return address;
     }

     /**
      * Returns the prefix length of this {@code LinkAddress}.
      */
     @IntRange(from = 0, to = 128)
     public int getPrefixLength() {
         return prefixLength;
     }

     /**
      * Returns the prefix length of this {@code LinkAddress}.
      * TODO: Delete all callers and remove in favour of getPrefixLength().
      * @hide
      */
     @UnsupportedAppUsage
     @IntRange(from = 0, to = 128)
     public int getNetworkPrefixLength() {
         return getPrefixLength();
     }

     /**
      * Returns the flags of this {@code LinkAddress}.
      */
     public int getFlags() {
         int flags = this.flags;
         if (deprecationTime != LIFETIME_UNKNOWN) {
             if (SystemClock.elapsedRealtime() >= deprecationTime) {
                 flags |= IFA_F_DEPRECATED;
             } else {
                 // If deprecation time is in the future, or permanent.
                 flags &= ~IFA_F_DEPRECATED;
             }
         }

         if (expirationTime == LIFETIME_PERMANENT) {
             flags |= IFA_F_PERMANENT;
         } else if (expirationTime != LIFETIME_UNKNOWN) {
             // If we know this address expired or will expire in the future, then this address
             // should not be permanent.
             flags &= ~IFA_F_PERMANENT;
         }

         // Do no touch the original flags. Return the adjusted flags here.
         return flags;
     }

     /**
      * Returns the scope of this {@code LinkAddress}.
      */
     public int getScope() {
         return scope;
     }

     /**
      * Get the deprecation time, as reported by {@link SystemClock#elapsedRealtime}, when this
      * {@link LinkAddress} will be or was deprecated. At the time existing connections can still use
      * this address until it expires, but new connections should use the new address.
      *
      * @return The deprecation time in milliseconds. {@link #LIFETIME_UNKNOWN} indicates this
      * information is not available. {@link #LIFETIME_PERMANENT} indicates this {@link LinkAddress}
      * will never be deprecated.
      *
      * @hide
      */
     @SystemApi
     @TestApi
     public long getDeprecationTime() {
         return deprecationTime;
     }

     /**
      * Get the expiration time, as reported by {@link SystemClock#elapsedRealtime}, when this
      * {@link LinkAddress} will expire and be removed from the interface.
      *
      * @return The expiration time in milliseconds. {@link #LIFETIME_UNKNOWN} indicates this
      * information is not available. {@link #LIFETIME_PERMANENT} indicates this {@link LinkAddress}
      * will never expire.
      *
      * @hide
      */
     @SystemApi
     @TestApi
     public long getExpirationTime() {
         return expirationTime;
     }

     /**
      * Returns true if this {@code LinkAddress} is global scope and preferred (i.e., not currently
      * deprecated).
      *
      * @hide
      */
     @TestApi
     @SystemApi
     public boolean isGlobalPreferred() {
         /**
          * Note that addresses flagged as IFA_F_OPTIMISTIC are
          * simultaneously flagged as IFA_F_TENTATIVE (when the tentative
          * state has cleared either DAD has succeeded or failed, and both
          * flags are cleared regardless).
          */
         int flags = getFlags();
         return (scope == RT_SCOPE_UNIVERSE
                 && !isIpv6ULA()
                 && (flags & (IFA_F_DADFAILED | IFA_F_DEPRECATED)) == 0L
                 && ((flags & IFA_F_TENTATIVE) == 0L || (flags & IFA_F_OPTIMISTIC) != 0L));
     }

     /**
      * Implement the Parcelable interface.
      */
     public int describeContents() {
         return 0;
     }

     /**
      * Implement the Parcelable interface.
      */
     public void writeToParcel(Parcel dest, int flags) {
         dest.writeByteArray(address.getAddress());
         dest.writeInt(prefixLength);
         dest.writeInt(this.flags);
         dest.writeInt(scope);
         dest.writeLong(deprecationTime);
         dest.writeLong(expirationTime);
     }

     /**
      * Implement the Parcelable interface.
      */
     public static final @android.annotation.NonNull Creator<LinkAddress> CREATOR =
         new Creator<LinkAddress>() {
             public LinkAddress createFromParcel(Parcel in) {
                 InetAddress address = null;
                 try {
                     address = InetAddress.getByAddress(in.createByteArray());
                 } catch (UnknownHostException e) {
                     // Nothing we can do here. When we call the constructor, we'll throw an
                     // IllegalArgumentException, because a LinkAddress can't have a null
                     // InetAddress.
                 }
                 int prefixLength = in.readInt();
                 int flags = in.readInt();
                 int scope = in.readInt();
                 long deprecationTime = in.readLong();
                 long expirationTime = in.readLong();
                 return new LinkAddress(address, prefixLength, flags, scope, deprecationTime,
                         expirationTime);
             }

             public LinkAddress[] newArray(int size) {
                 return new LinkAddress[size];
             }
         };
 }
	/*
	* Copyright (C) 2010 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.system.OsConstants.IFA_F_DADFAILED;
	import static android.system.OsConstants.IFA_F_DEPRECATED;
	import static android.system.OsConstants.IFA_F_OPTIMISTIC;
	import static android.system.OsConstants.IFA_F_PERMANENT;
	import static android.system.OsConstants.IFA_F_TENTATIVE;
	import static android.system.OsConstants.RT_SCOPE_HOST;
	import static android.system.OsConstants.RT_SCOPE_LINK;
	import static android.system.OsConstants.RT_SCOPE_SITE;
	import static android.system.OsConstants.RT_SCOPE_UNIVERSE;

	import android.annotation.IntRange;
	import android.annotation.NonNull;
	import android.annotation.Nullable;
	import android.annotation.SystemApi;
	import android.annotation.TestApi;
	import android.compat.annotation.UnsupportedAppUsage;
	import android.os.Build;
	import android.os.Parcel;
	import android.os.Parcelable;
	import android.os.SystemClock;
	import android.util.Pair;

	import java.net.Inet4Address;
	import java.net.Inet6Address;
	import java.net.InetAddress;
	import java.net.InterfaceAddress;
	import java.net.UnknownHostException;
	import java.util.Objects;

	/**
	* Identifies an IP address on a network link.
	*
	* A {@code LinkAddress} consists of:
	* <ul>
	* <li>An IP address and prefix length (e.g., {@code 2001:db8::1/64} or {@code 192.0.2.1/24}).
	* The address must be unicast, as multicast addresses cannot be assigned to interfaces.
	* <li>Address flags: A bitmask of {@code OsConstants.IFA_F_*} values representing properties
	* of the address (e.g., {@code android.system.OsConstants.IFA_F_OPTIMISTIC}).
	* <li>Address scope: One of the {@code OsConstants.IFA_F_*} values; defines the scope in which
	* the address is unique (e.g.,
	* {@code android.system.OsConstants.RT_SCOPE_LINK} or
	* {@code android.system.OsConstants.RT_SCOPE_UNIVERSE}).
	* </ul>
	*/
	public class LinkAddress implements Parcelable {

	/**
	* Indicates the deprecation or expiration time is unknown
	* @hide
	*/
	@SystemApi
	public static final long LIFETIME_UNKNOWN = -1;

	/**
	* Indicates this address is permanent.
	* @hide
	*/
	@SystemApi
	public static final long LIFETIME_PERMANENT = Long.MAX_VALUE;

	/**
	* IPv4 or IPv6 address.
	*/
	@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
	private InetAddress address;

	/**
	* Prefix length.
	*/
	@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
	private int prefixLength;

	/**
	* Address flags. A bitmask of {@code IFA_F_*} values. Note that {@link #getFlags()} may not
	* return these exact values. For example, it may set or clear the {@code IFA_F_DEPRECATED}
	* flag depending on the current preferred lifetime.
	*/
	private int flags;

	/**
	* Address scope. One of the RT_SCOPE_* constants.
	*/
	private int scope;

	/**
	* The time, as reported by {@link SystemClock#elapsedRealtime}, when this LinkAddress will be
	* or was deprecated. At the time existing connections can still use this address until it
	* expires, but new connections should use the new address. {@link #LIFETIME_UNKNOWN} indicates
	* this information is not available. {@link #LIFETIME_PERMANENT} indicates this
	* {@link LinkAddress} will never be deprecated.
	*/
	private long deprecationTime;

	/**
	* The time, as reported by {@link SystemClock#elapsedRealtime}, when this {@link LinkAddress}
	* will expire and be removed from the interface. {@link #LIFETIME_UNKNOWN} indicates this
	* information is not available. {@link #LIFETIME_PERMANENT} indicates this {@link LinkAddress}
	* will never expire.
	*/
	private long expirationTime;

	/**
	* Utility function to determines the scope of a unicast address. Per RFC 4291 section 2.5 and
	* RFC 6724 section 3.2.
	* @hide
	*/
	private static int scopeForUnicastAddress(InetAddress addr) {
	if (addr.isAnyLocalAddress()) {
	return RT_SCOPE_HOST;
	}

	if (addr.isLoopbackAddress() \|\| addr.isLinkLocalAddress()) {
	return RT_SCOPE_LINK;
	}

	// isSiteLocalAddress() returns true for private IPv4 addresses, but RFC 6724 section 3.2
	// says that they are assigned global scope.
	if (!(addr instanceof Inet4Address) && addr.isSiteLocalAddress()) {
	return RT_SCOPE_SITE;
	}

	return RT_SCOPE_UNIVERSE;
	}

	/**
	* Utility function to check if \|address\| is a Unique Local IPv6 Unicast Address
	* (a.k.a. "ULA"; RFC 4193).
	*
	* Per RFC 4193 section 8, fc00::/7 identifies these addresses.
	*/
	private boolean isIpv6ULA() {
	if (isIpv6()) {
	byte[] bytes = address.getAddress();
	return ((bytes[0] & (byte)0xfe) == (byte)0xfc);
	}
	return false;
	}

	/**
	* @return true if the address is IPv6.
	* @hide
	*/
	@TestApi
	@SystemApi
	public boolean isIpv6() {
	return address instanceof Inet6Address;
	}

	/**
	* For backward compatibility.
	* This was annotated with @UnsupportedAppUsage in P, so we can't remove the method completely
	* just yet.
	* @return true if the address is IPv6.
	* @hide
	*/
	@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
	public boolean isIPv6() {
	return isIpv6();
	}

	/**
	* @return true if the address is IPv4 or is a mapped IPv4 address.
	* @hide
	*/
	@TestApi
	@SystemApi
	public boolean isIpv4() {
	return address instanceof Inet4Address;
	}

	/**
	* Utility function for the constructors.
	*/
	private void init(InetAddress address, int prefixLength, int flags, int scope,
	long deprecationTime, long expirationTime) {
	if (address == null \|\|
	address.isMulticastAddress() \|\|
	prefixLength < 0 \|\|
	(address instanceof Inet4Address && prefixLength > 32) \|\|
	(prefixLength > 128)) {
	throw new IllegalArgumentException("Bad LinkAddress params " + address +
	"/" + prefixLength);
	}

	// deprecation time and expiration time must be both provided, or neither.
	if ((deprecationTime == LIFETIME_UNKNOWN) != (expirationTime == LIFETIME_UNKNOWN)) {
	throw new IllegalArgumentException(
	"Must not specify only one of deprecation time and expiration time");
	}

	// deprecation time needs to be a positive value.
	if (deprecationTime != LIFETIME_UNKNOWN && deprecationTime < 0) {
	throw new IllegalArgumentException("invalid deprecation time " + deprecationTime);
	}

	// expiration time needs to be a positive value.
	if (expirationTime != LIFETIME_UNKNOWN && expirationTime < 0) {
	throw new IllegalArgumentException("invalid expiration time " + expirationTime);
	}

	// expiration time can't be earlier than deprecation time
	if (deprecationTime != LIFETIME_UNKNOWN && expirationTime != LIFETIME_UNKNOWN
	&& expirationTime < deprecationTime) {
	throw new IllegalArgumentException("expiration earlier than deprecation ("
	+ deprecationTime + ", " + expirationTime + ")");
	}

	this.address = address;
	this.prefixLength = prefixLength;
	this.flags = flags;
	this.scope = scope;
	this.deprecationTime = deprecationTime;
	this.expirationTime = expirationTime;
	}

	/**
	* Constructs a new {@code LinkAddress} from an {@code InetAddress} and prefix length, with
	* the specified flags and scope. Flags and scope are not checked for validity.
	*
	* @param address The IP address.
	* @param prefixLength The prefix length. Must be >= 0 and <= (32 or 128) (IPv4 or IPv6).
	* @param flags A bitmask of {@code IFA_F_*} values representing properties of the address.
	* @param scope An integer defining the scope in which the address is unique (e.g.,
	* {@link OsConstants#RT_SCOPE_LINK} or {@link OsConstants#RT_SCOPE_SITE}).
	* @hide
	*/
	@SystemApi
	@TestApi
	public LinkAddress(@NonNull InetAddress address, @IntRange(from = 0, to = 128) int prefixLength,
	int flags, int scope) {
	init(address, prefixLength, flags, scope, LIFETIME_UNKNOWN, LIFETIME_UNKNOWN);
	}

	/**
	* Constructs a new {@code LinkAddress} from an {@code InetAddress}, prefix length, with
	* the specified flags, scope, deprecation time, and expiration time. Flags and scope are not
	* checked for validity. The value of the {@code IFA_F_DEPRECATED} and {@code IFA_F_PERMANENT}
	* flag will be adjusted based on the passed-in lifetimes.
	*
	* @param address The IP address.
	* @param prefixLength The prefix length. Must be >= 0 and <= (32 or 128) (IPv4 or IPv6).
	* @param flags A bitmask of {@code IFA_F_*} values representing properties of the address.
	* @param scope An integer defining the scope in which the address is unique (e.g.,
	* {@link OsConstants#RT_SCOPE_LINK} or {@link OsConstants#RT_SCOPE_SITE}).
	* @param deprecationTime The time, as reported by {@link SystemClock#elapsedRealtime}, when
	* this {@link LinkAddress} will be or was deprecated. At the time
	* existing connections can still use this address until it expires, but
	* new connections should use the new address. {@link #LIFETIME_UNKNOWN}
	* indicates this information is not available.
	* {@link #LIFETIME_PERMANENT} indicates this {@link LinkAddress} will
	* never be deprecated.
	* @param expirationTime The time, as reported by {@link SystemClock#elapsedRealtime}, when this
	* {@link LinkAddress} will expire and be removed from the interface.
	* {@link #LIFETIME_UNKNOWN} indicates this information is not available.
	* {@link #LIFETIME_PERMANENT} indicates this {@link LinkAddress} will
	* never expire.
	* @hide
	*/
	@SystemApi
	@TestApi
	public LinkAddress(@NonNull InetAddress address, @IntRange(from = 0, to = 128) int prefixLength,
	int flags, int scope, long deprecationTime, long expirationTime) {
	init(address, prefixLength, flags, scope, deprecationTime, expirationTime);
	}

	/**
	* Constructs a new {@code LinkAddress} from an {@code InetAddress} and a prefix length.
	* The flags are set to zero and the scope is determined from the address.
	* @param address The IP address.
	* @param prefixLength The prefix length. Must be >= 0 and <= (32 or 128) (IPv4 or IPv6).
	* @hide
	*/
	@SystemApi
	@TestApi
	public LinkAddress(@NonNull InetAddress address,
	@IntRange(from = 0, to = 128) int prefixLength) {
	this(address, prefixLength, 0, 0);
	this.scope = scopeForUnicastAddress(address);
	}

	/**
	* Constructs a new {@code LinkAddress} from an {@code InterfaceAddress}.
	* The flags are set to zero and the scope is determined from the address.
	* @param interfaceAddress The interface address.
	* @hide
	*/
	public LinkAddress(@NonNull InterfaceAddress interfaceAddress) {
	this(interfaceAddress.getAddress(),
	interfaceAddress.getNetworkPrefixLength());
	}

	/**
	* Constructs a new {@code LinkAddress} from a string such as "192.0.2.5/24" or
	* "2001:db8::1/64". The flags are set to zero and the scope is determined from the address.
	* @param address The string to parse.
	* @hide
	*/
	@SystemApi
	@TestApi
	public LinkAddress(@NonNull String address) {
	this(address, 0, 0);
	this.scope = scopeForUnicastAddress(this.address);
	}

	/**
	* Constructs a new {@code LinkAddress} from a string such as "192.0.2.5/24" or
	* "2001:db8::1/64", with the specified flags and scope.
	* @param address The string to parse.
	* @param flags The address flags.
	* @param scope The address scope.
	* @hide
	*/
	@SystemApi
	@TestApi
	public LinkAddress(@NonNull String address, int flags, int scope) {
	// This may throw an IllegalArgumentException; catching it is the caller's responsibility.
	// TODO: consider rejecting mapped IPv4 addresses such as "::ffff:192.0.2.5/24".
	Pair<InetAddress, Integer> ipAndMask = NetworkUtils.parseIpAndMask(address);
	init(ipAndMask.first, ipAndMask.second, flags, scope, LIFETIME_UNKNOWN, LIFETIME_UNKNOWN);
	}

	/**
	* Returns a string representation of this address, such as "192.0.2.1/24" or "2001:db8::1/64".
	* The string representation does not contain the flags and scope, just the address and prefix
	* length.
	*/
	@Override
	public String toString() {
	return address.getHostAddress() + "/" + prefixLength;
	}

	/**
	* Compares this {@code LinkAddress} instance against {@code obj}. Two addresses are equal if
	* their address, prefix length, flags and scope are equal. Thus, for example, two addresses
	* that have the same address and prefix length are not equal if one of them is deprecated and
	* the other is not.
	*
	* @param obj the object to be tested for equality.
	* @return {@code true} if both objects are equal, {@code false} otherwise.
	*/
	@Override
	public boolean equals(Object obj) {
	if (!(obj instanceof LinkAddress)) {
	return false;
	}
	LinkAddress linkAddress = (LinkAddress) obj;
	return this.address.equals(linkAddress.address)
	&& this.prefixLength == linkAddress.prefixLength
	&& this.flags == linkAddress.flags
	&& this.scope == linkAddress.scope
	&& this.deprecationTime == linkAddress.deprecationTime
	&& this.expirationTime == linkAddress.expirationTime;
	}

	/**
	* Returns a hashcode for this address.
	*/
	@Override
	public int hashCode() {
	return Objects.hash(address, prefixLength, flags, scope, deprecationTime, expirationTime);
	}

	/**
	* Determines whether this {@code LinkAddress} and the provided {@code LinkAddress}
	* represent the same address. Two {@code LinkAddresses} represent the same address
	* if they have the same IP address and prefix length, even if their properties are
	* different.
	*
	* @param other the {@code LinkAddress} to compare to.
	* @return {@code true} if both objects have the same address and prefix length, {@code false}
	* otherwise.
	* @hide
	*/
	@TestApi
	@SystemApi
	public boolean isSameAddressAs(@Nullable LinkAddress other) {
	if (other == null) {
	return false;
	}
	return address.equals(other.address) && prefixLength == other.prefixLength;
	}

	/**
	* Returns the {@link InetAddress} of this {@code LinkAddress}.
	*/
	public InetAddress getAddress() {
	return address;
	}

	/**
	* Returns the prefix length of this {@code LinkAddress}.
	*/
	@IntRange(from = 0, to = 128)
	public int getPrefixLength() {
	return prefixLength;
	}

	/**
	* Returns the prefix length of this {@code LinkAddress}.
	* TODO: Delete all callers and remove in favour of getPrefixLength().
	* @hide
	*/
	@UnsupportedAppUsage
	@IntRange(from = 0, to = 128)
	public int getNetworkPrefixLength() {
	return getPrefixLength();
	}

	/**
	* Returns the flags of this {@code LinkAddress}.
	*/
	public int getFlags() {
	int flags = this.flags;
	if (deprecationTime != LIFETIME_UNKNOWN) {
	if (SystemClock.elapsedRealtime() >= deprecationTime) {
	flags \|= IFA_F_DEPRECATED;
	} else {
	// If deprecation time is in the future, or permanent.
	flags &= ~IFA_F_DEPRECATED;
	}
	}

	if (expirationTime == LIFETIME_PERMANENT) {
	flags \|= IFA_F_PERMANENT;
	} else if (expirationTime != LIFETIME_UNKNOWN) {
	// If we know this address expired or will expire in the future, then this address
	// should not be permanent.
	flags &= ~IFA_F_PERMANENT;
	}

	// Do no touch the original flags. Return the adjusted flags here.
	return flags;
	}

	/**
	* Returns the scope of this {@code LinkAddress}.
	*/
	public int getScope() {
	return scope;
	}

	/**
	* Get the deprecation time, as reported by {@link SystemClock#elapsedRealtime}, when this
	* {@link LinkAddress} will be or was deprecated. At the time existing connections can still use
	* this address until it expires, but new connections should use the new address.
	*
	* @return The deprecation time in milliseconds. {@link #LIFETIME_UNKNOWN} indicates this
	* information is not available. {@link #LIFETIME_PERMANENT} indicates this {@link LinkAddress}
	* will never be deprecated.
	*
	* @hide
	*/
	@SystemApi
	@TestApi
	public long getDeprecationTime() {
	return deprecationTime;
	}

	/**
	* Get the expiration time, as reported by {@link SystemClock#elapsedRealtime}, when this
	* {@link LinkAddress} will expire and be removed from the interface.
	*
	* @return The expiration time in milliseconds. {@link #LIFETIME_UNKNOWN} indicates this
	* information is not available. {@link #LIFETIME_PERMANENT} indicates this {@link LinkAddress}
	* will never expire.
	*
	* @hide
	*/
	@SystemApi
	@TestApi
	public long getExpirationTime() {
	return expirationTime;
	}

	/**
	* Returns true if this {@code LinkAddress} is global scope and preferred (i.e., not currently
	* deprecated).
	*
	* @hide
	*/
	@TestApi
	@SystemApi
	public boolean isGlobalPreferred() {
	/**
	* Note that addresses flagged as IFA_F_OPTIMISTIC are
	* simultaneously flagged as IFA_F_TENTATIVE (when the tentative
	* state has cleared either DAD has succeeded or failed, and both
	* flags are cleared regardless).
	*/
	int flags = getFlags();
	return (scope == RT_SCOPE_UNIVERSE
	&& !isIpv6ULA()
	&& (flags & (IFA_F_DADFAILED \| IFA_F_DEPRECATED)) == 0L
	&& ((flags & IFA_F_TENTATIVE) == 0L \|\| (flags & IFA_F_OPTIMISTIC) != 0L));
	}

	/**
	* Implement the Parcelable interface.
	*/
	public int describeContents() {
	return 0;
	}

	/**
	* Implement the Parcelable interface.
	*/
	public void writeToParcel(Parcel dest, int flags) {
	dest.writeByteArray(address.getAddress());
	dest.writeInt(prefixLength);
	dest.writeInt(this.flags);
	dest.writeInt(scope);
	dest.writeLong(deprecationTime);
	dest.writeLong(expirationTime);
	}

	/**
	* Implement the Parcelable interface.
	*/
	public static final @android.annotation.NonNull Creator<LinkAddress> CREATOR =
	new Creator<LinkAddress>() {
	public LinkAddress createFromParcel(Parcel in) {
	InetAddress address = null;
	try {
	address = InetAddress.getByAddress(in.createByteArray());
	} catch (UnknownHostException e) {
	// Nothing we can do here. When we call the constructor, we'll throw an
	// IllegalArgumentException, because a LinkAddress can't have a null
	// InetAddress.
	}
	int prefixLength = in.readInt();
	int flags = in.readInt();
	int scope = in.readInt();
	long deprecationTime = in.readLong();
	long expirationTime = in.readLong();
	return new LinkAddress(address, prefixLength, flags, scope, deprecationTime,
	expirationTime);
	}

	public LinkAddress[] newArray(int size) {
	return new LinkAddress[size];
	}
	};
	}