1 /* 2 * Copyright (C) 2019 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.annotation.NonNull; 20 import android.annotation.Nullable; 21 import android.provider.DeviceConfig; 22 import android.util.SparseArray; 23 24 import java.io.FileDescriptor; 25 import java.io.IOException; 26 import java.net.Inet4Address; 27 import java.net.Inet6Address; 28 import java.net.InetAddress; 29 import java.net.SocketException; 30 import java.util.List; 31 import java.util.function.Predicate; 32 33 /** 34 * Collection of utilities for the network stack. 35 */ 36 public class NetworkStackUtils { 37 // TODO: Refer to DeviceConfig definition. 38 public static final String NAMESPACE_CONNECTIVITY = "connectivity"; 39 40 /** 41 * A list of captive portal detection specifications used in addition to the fallback URLs. 42 * Each spec has the format url@@/@@statusCodeRegex@@/@@contentRegex. Specs are separated 43 * by "@@,@@". 44 */ 45 public static final String CAPTIVE_PORTAL_FALLBACK_PROBE_SPECS = 46 "captive_portal_fallback_probe_specs"; 47 48 /** 49 * A comma separated list of URLs used for captive portal detection in addition to the 50 * fallback HTTP url associated with the CAPTIVE_PORTAL_FALLBACK_URL settings. 51 */ 52 public static final String CAPTIVE_PORTAL_OTHER_FALLBACK_URLS = 53 "captive_portal_other_fallback_urls"; 54 55 /** 56 * Which User-Agent string to use in the header of the captive portal detection probes. 57 * The User-Agent field is unset when this setting has no value (HttpUrlConnection default). 58 */ 59 public static final String CAPTIVE_PORTAL_USER_AGENT = "captive_portal_user_agent"; 60 61 /** 62 * Whether to use HTTPS for network validation. This is enabled by default and the setting 63 * needs to be set to 0 to disable it. This setting is a misnomer because captive portals 64 * don't actually use HTTPS, but it's consistent with the other settings. 65 */ 66 public static final String CAPTIVE_PORTAL_USE_HTTPS = "captive_portal_use_https"; 67 68 /** 69 * The URL used for HTTPS captive portal detection upon a new connection. 70 * A 204 response code from the server is used for validation. 71 */ 72 public static final String CAPTIVE_PORTAL_HTTPS_URL = "captive_portal_https_url"; 73 74 /** 75 * The URL used for HTTP captive portal detection upon a new connection. 76 * A 204 response code from the server is used for validation. 77 */ 78 public static final String CAPTIVE_PORTAL_HTTP_URL = "captive_portal_http_url"; 79 80 /** 81 * The URL used for fallback HTTP captive portal detection when previous HTTP 82 * and HTTPS captive portal detection attemps did not return a conclusive answer. 83 */ 84 public static final String CAPTIVE_PORTAL_FALLBACK_URL = "captive_portal_fallback_url"; 85 86 /** 87 * What to do when connecting a network that presents a captive portal. 88 * Must be one of the CAPTIVE_PORTAL_MODE_* constants above. 89 * 90 * The default for this setting is CAPTIVE_PORTAL_MODE_PROMPT. 91 */ 92 public static final String CAPTIVE_PORTAL_MODE = "captive_portal_mode"; 93 94 /** 95 * Don't attempt to detect captive portals. 96 */ 97 public static final int CAPTIVE_PORTAL_MODE_IGNORE = 0; 98 99 /** 100 * When detecting a captive portal, display a notification that 101 * prompts the user to sign in. 102 */ 103 public static final int CAPTIVE_PORTAL_MODE_PROMPT = 1; 104 105 /** 106 * When detecting a captive portal, immediately disconnect from the 107 * network and do not reconnect to that network in the future. 108 */ 109 public static final int CAPTIVE_PORTAL_MODE_AVOID = 2; 110 111 static { 112 System.loadLibrary("networkstackutilsjni"); 113 } 114 115 /** 116 * @return True if the array is null or 0-length. 117 */ isEmpty(T[] array)118 public static <T> boolean isEmpty(T[] array) { 119 return array == null || array.length == 0; 120 } 121 122 /** 123 * Close a socket, ignoring any exception while closing. 124 */ closeSocketQuietly(FileDescriptor fd)125 public static void closeSocketQuietly(FileDescriptor fd) { 126 try { 127 SocketUtils.closeSocket(fd); 128 } catch (IOException ignored) { 129 } 130 } 131 132 /** 133 * Returns an int array from the given Integer list. 134 */ convertToIntArray(@onNull List<Integer> list)135 public static int[] convertToIntArray(@NonNull List<Integer> list) { 136 int[] array = new int[list.size()]; 137 for (int i = 0; i < list.size(); i++) { 138 array[i] = list.get(i); 139 } 140 return array; 141 } 142 143 /** 144 * Returns a long array from the given long list. 145 */ convertToLongArray(@onNull List<Long> list)146 public static long[] convertToLongArray(@NonNull List<Long> list) { 147 long[] array = new long[list.size()]; 148 for (int i = 0; i < list.size(); i++) { 149 array[i] = list.get(i); 150 } 151 return array; 152 } 153 154 /** 155 * @return True if there exists at least one element in the sparse array for which 156 * condition {@code predicate} 157 */ any(SparseArray<T> array, Predicate<T> predicate)158 public static <T> boolean any(SparseArray<T> array, Predicate<T> predicate) { 159 for (int i = 0; i < array.size(); ++i) { 160 if (predicate.test(array.valueAt(i))) { 161 return true; 162 } 163 } 164 return false; 165 } 166 167 /** 168 * Look up the value of a property for a particular namespace from {@link DeviceConfig}. 169 * @param namespace The namespace containing the property to look up. 170 * @param name The name of the property to look up. 171 * @param defaultValue The value to return if the property does not exist or has no valid value. 172 * @return the corresponding value, or defaultValue if none exists. 173 */ 174 @Nullable getDeviceConfigProperty(@onNull String namespace, @NonNull String name, @Nullable String defaultValue)175 public static String getDeviceConfigProperty(@NonNull String namespace, @NonNull String name, 176 @Nullable String defaultValue) { 177 String value = DeviceConfig.getProperty(namespace, name); 178 return value != null ? value : defaultValue; 179 } 180 181 /** 182 * Look up the value of a property for a particular namespace from {@link DeviceConfig}. 183 * @param namespace The namespace containing the property to look up. 184 * @param name The name of the property to look up. 185 * @param defaultValue The value to return if the property does not exist or has no non-null 186 * value. 187 * @return the corresponding value, or defaultValue if none exists. 188 */ getDeviceConfigPropertyInt(@onNull String namespace, @NonNull String name, int defaultValue)189 public static int getDeviceConfigPropertyInt(@NonNull String namespace, @NonNull String name, 190 int defaultValue) { 191 String value = getDeviceConfigProperty(namespace, name, null /* defaultValue */); 192 try { 193 return (value != null) ? Integer.parseInt(value) : defaultValue; 194 } catch (NumberFormatException e) { 195 return defaultValue; 196 } 197 } 198 199 /** 200 * Attaches a socket filter that accepts DHCP packets to the given socket. 201 */ attachDhcpFilter(FileDescriptor fd)202 public static native void attachDhcpFilter(FileDescriptor fd) throws SocketException; 203 204 /** 205 * Attaches a socket filter that accepts ICMPv6 router advertisements to the given socket. 206 * @param fd the socket's {@link FileDescriptor}. 207 * @param packetType the hardware address type, one of ARPHRD_*. 208 */ attachRaFilter(FileDescriptor fd, int packetType)209 public static native void attachRaFilter(FileDescriptor fd, int packetType) 210 throws SocketException; 211 212 /** 213 * Attaches a socket filter that accepts L2-L4 signaling traffic required for IP connectivity. 214 * 215 * This includes: all ARP, ICMPv6 RS/RA/NS/NA messages, and DHCPv4 exchanges. 216 * 217 * @param fd the socket's {@link FileDescriptor}. 218 * @param packetType the hardware address type, one of ARPHRD_*. 219 */ attachControlPacketFilter(FileDescriptor fd, int packetType)220 public static native void attachControlPacketFilter(FileDescriptor fd, int packetType) 221 throws SocketException; 222 223 /** 224 * Add an entry into the ARP cache. 225 */ addArpEntry(Inet4Address ipv4Addr, android.net.MacAddress ethAddr, String ifname, FileDescriptor fd)226 public static void addArpEntry(Inet4Address ipv4Addr, android.net.MacAddress ethAddr, 227 String ifname, FileDescriptor fd) throws IOException { 228 addArpEntry(ethAddr.toByteArray(), ipv4Addr.getAddress(), ifname, fd); 229 } 230 addArpEntry(byte[] ethAddr, byte[] netAddr, String ifname, FileDescriptor fd)231 private static native void addArpEntry(byte[] ethAddr, byte[] netAddr, String ifname, 232 FileDescriptor fd) throws IOException; 233 234 /** 235 * Return IP address and port in a string format. 236 */ addressAndPortToString(InetAddress address, int port)237 public static String addressAndPortToString(InetAddress address, int port) { 238 return String.format( 239 (address instanceof Inet6Address) ? "[%s]:%d" : "%s:%d", 240 address.getHostAddress(), port); 241 } 242 } 243