1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.net.util; 18 19 import android.net.IpPrefix; 20 import android.net.LinkAddress; 21 import android.net.LinkProperties; 22 23 import java.net.Inet4Address; 24 import java.net.InetAddress; 25 import java.util.Collections; 26 import java.util.HashSet; 27 import java.util.Set; 28 29 30 /** 31 * @hide 32 */ 33 public class PrefixUtils { 34 private static final IpPrefix[] MIN_NON_FORWARDABLE_PREFIXES = { 35 pfx("127.0.0.0/8"), // IPv4 loopback 36 pfx("169.254.0.0/16"), // IPv4 link-local, RFC3927#section-8 37 pfx("::/3"), 38 pfx("fe80::/64"), // IPv6 link-local 39 pfx("fc00::/7"), // IPv6 ULA 40 pfx("ff02::/8"), // IPv6 link-local multicast 41 }; 42 43 public static final IpPrefix DEFAULT_WIFI_P2P_PREFIX = pfx("192.168.49.0/24"); 44 getNonForwardablePrefixes()45 public static Set<IpPrefix> getNonForwardablePrefixes() { 46 final HashSet<IpPrefix> prefixes = new HashSet<>(); 47 addNonForwardablePrefixes(prefixes); 48 return prefixes; 49 } 50 addNonForwardablePrefixes(Set<IpPrefix> prefixes)51 public static void addNonForwardablePrefixes(Set<IpPrefix> prefixes) { 52 Collections.addAll(prefixes, MIN_NON_FORWARDABLE_PREFIXES); 53 } 54 localPrefixesFrom(LinkProperties lp)55 public static Set<IpPrefix> localPrefixesFrom(LinkProperties lp) { 56 final HashSet<IpPrefix> localPrefixes = new HashSet<>(); 57 if (lp == null) return localPrefixes; 58 59 for (LinkAddress addr : lp.getAllLinkAddresses()) { 60 if (addr.getAddress().isLinkLocalAddress()) continue; 61 localPrefixes.add(asIpPrefix(addr)); 62 } 63 // TODO: Add directly-connected routes as well (ones from which we did 64 // not also form a LinkAddress)? 65 66 return localPrefixes; 67 } 68 asIpPrefix(LinkAddress addr)69 public static IpPrefix asIpPrefix(LinkAddress addr) { 70 return new IpPrefix(addr.getAddress(), addr.getPrefixLength()); 71 } 72 ipAddressAsPrefix(InetAddress ip)73 public static IpPrefix ipAddressAsPrefix(InetAddress ip) { 74 final int bitLength = (ip instanceof Inet4Address) 75 ? NetworkConstants.IPV4_ADDR_BITS 76 : NetworkConstants.IPV6_ADDR_BITS; 77 return new IpPrefix(ip, bitLength); 78 } 79 pfx(String prefixStr)80 private static IpPrefix pfx(String prefixStr) { 81 return new IpPrefix(prefixStr); 82 } 83 } 84