2 * Copyright (C) 2008 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
19 import java.net.InetAddress;
20 import java.net.Inet4Address;
21 import java.net.Inet6Address;
22 import java.net.UnknownHostException;
23 import java.util.Collection;
25 import android.util.Log;
28 * Native methods for managing network interfaces.
32 public class NetworkUtils {
34 private static final String TAG = "NetworkUtils";
36 /** Bring the named network interface up. */
37 public native static int enableInterface(String interfaceName);
39 /** Bring the named network interface down. */
40 public native static int disableInterface(String interfaceName);
42 /** Setting bit 0 indicates reseting of IPv4 addresses required */
43 public static final int RESET_IPV4_ADDRESSES = 0x01;
45 /** Setting bit 1 indicates reseting of IPv4 addresses required */
46 public static final int RESET_IPV6_ADDRESSES = 0x02;
48 /** Reset all addresses */
49 public static final int RESET_ALL_ADDRESSES = RESET_IPV4_ADDRESSES | RESET_IPV6_ADDRESSES;
52 * Reset IPv6 or IPv4 sockets that are connected via the named interface.
54 * @param interfaceName is the interface to reset
55 * @param mask {@see #RESET_IPV4_ADDRESSES} and {@see #RESET_IPV6_ADDRESSES}
57 public native static int resetConnections(String interfaceName, int mask);
60 * Start the DHCP client daemon, in order to have it request addresses
61 * for the named interface, and then configure the interface with those
62 * addresses. This call blocks until it obtains a result (either success
63 * or failure) from the daemon.
64 * @param interfaceName the name of the interface to configure
65 * @param ipInfo if the request succeeds, this object is filled in with
66 * the IP address information.
67 * @return {@code true} for success, {@code false} for failure
69 public native static boolean runDhcp(String interfaceName, DhcpInfoInternal ipInfo);
72 * Initiate renewal on the Dhcp client daemon. This call blocks until it obtains
73 * a result (either success or failure) from the daemon.
74 * @param interfaceName the name of the interface to configure
75 * @param ipInfo if the request succeeds, this object is filled in with
76 * the IP address information.
77 * @return {@code true} for success, {@code false} for failure
79 public native static boolean runDhcpRenew(String interfaceName, DhcpInfoInternal ipInfo);
82 * Shut down the DHCP client daemon.
83 * @param interfaceName the name of the interface for which the daemon
85 * @return {@code true} for success, {@code false} for failure
87 public native static boolean stopDhcp(String interfaceName);
90 * Release the current DHCP lease.
91 * @param interfaceName the name of the interface for which the lease should
93 * @return {@code true} for success, {@code false} for failure
95 public native static boolean releaseDhcpLease(String interfaceName);
98 * Return the last DHCP-related error message that was recorded.
99 * <p/>NOTE: This string is not localized, but currently it is only
101 * @return the most recent error message, if any
103 public native static String getDhcpError();
106 * Convert a IPv4 address from an integer to an InetAddress.
107 * @param hostAddress an int corresponding to the IPv4 address in network byte order
109 public static InetAddress intToInetAddress(int hostAddress) {
110 byte[] addressBytes = { (byte)(0xff & hostAddress),
111 (byte)(0xff & (hostAddress >> 8)),
112 (byte)(0xff & (hostAddress >> 16)),
113 (byte)(0xff & (hostAddress >> 24)) };
116 return InetAddress.getByAddress(addressBytes);
117 } catch (UnknownHostException e) {
118 throw new AssertionError();
123 * Convert a IPv4 address from an InetAddress to an integer
124 * @param inetAddr is an InetAddress corresponding to the IPv4 address
125 * @return the IP address as an integer in network byte order
127 public static int inetAddressToInt(InetAddress inetAddr)
128 throws IllegalArgumentException {
129 byte [] addr = inetAddr.getAddress();
130 if (addr.length != 4) {
131 throw new IllegalArgumentException("Not an IPv4 address");
133 return ((addr[3] & 0xff) << 24) | ((addr[2] & 0xff) << 16) |
134 ((addr[1] & 0xff) << 8) | (addr[0] & 0xff);
138 * Convert a network prefix length to an IPv4 netmask integer
139 * @param prefixLength
140 * @return the IPv4 netmask as an integer in network byte order
142 public static int prefixLengthToNetmaskInt(int prefixLength)
143 throws IllegalArgumentException {
144 if (prefixLength < 0 || prefixLength > 32) {
145 throw new IllegalArgumentException("Invalid prefix length (0 <= prefix <= 32)");
147 int value = 0xffffffff << (32 - prefixLength);
148 return Integer.reverseBytes(value);
152 * Convert a IPv4 netmask integer to a prefix length
153 * @param netmask as an integer in network byte order
154 * @return the network prefix length
156 public static int netmaskIntToPrefixLength(int netmask) {
157 return Integer.bitCount(netmask);
161 * Create an InetAddress from a string where the string must be a standard
162 * representation of a V4 or V6 address. Avoids doing a DNS lookup on failure
163 * but it will throw an IllegalArgumentException in that case.
165 * @return the InetAddress
168 public static InetAddress numericToInetAddress(String addrString)
169 throws IllegalArgumentException {
170 return InetAddress.parseNumericAddress(addrString);
174 * Get InetAddress masked with prefixLength. Will never return null.
175 * @param IP address which will be masked with specified prefixLength
176 * @param prefixLength the prefixLength used to mask the IP
178 public static InetAddress getNetworkPart(InetAddress address, int prefixLength) {
179 if (address == null) {
180 throw new RuntimeException("getNetworkPart doesn't accept null address");
183 byte[] array = address.getAddress();
185 if (prefixLength < 0 || prefixLength > array.length * 8) {
186 throw new RuntimeException("getNetworkPart - bad prefixLength");
189 int offset = prefixLength / 8;
190 int reminder = prefixLength % 8;
191 byte mask = (byte)(0xFF << (8 - reminder));
193 if (offset < array.length) array[offset] = (byte)(array[offset] & mask);
197 for (; offset < array.length; offset++) {
201 InetAddress netPart = null;
203 netPart = InetAddress.getByAddress(array);
204 } catch (UnknownHostException e) {
205 throw new RuntimeException("getNetworkPart error - " + e.toString());
211 * Check if IP address type is consistent between two InetAddress.
212 * @return true if both are the same type. False otherwise.
214 public static boolean addressTypeMatches(InetAddress left, InetAddress right) {
215 return (((left instanceof Inet4Address) && (right instanceof Inet4Address)) ||
216 ((left instanceof Inet6Address) && (right instanceof Inet6Address)));
220 * Convert a 32 char hex string into a Inet6Address.
221 * throws a runtime exception if the string isn't 32 chars, isn't hex or can't be
222 * made into an Inet6Address
223 * @param addrHexString a 32 character hex string representing an IPv6 addr
224 * @return addr an InetAddress representation for the string
226 public static InetAddress hexToInet6Address(String addrHexString)
227 throws IllegalArgumentException {
229 return numericToInetAddress(String.format("%s:%s:%s:%s:%s:%s:%s:%s",
230 addrHexString.substring(0,4), addrHexString.substring(4,8),
231 addrHexString.substring(8,12), addrHexString.substring(12,16),
232 addrHexString.substring(16,20), addrHexString.substring(20,24),
233 addrHexString.substring(24,28), addrHexString.substring(28,32)));
234 } catch (Exception e) {
235 Log.e("NetworkUtils", "error in hexToInet6Address(" + addrHexString + "): " + e);
236 throw new IllegalArgumentException(e);
241 * Create a string array of host addresses from a collection of InetAddresses
242 * @param addrs a Collection of InetAddresses
243 * @return an array of Strings containing their host addresses
245 public static String[] makeStrings(Collection<InetAddress> addrs) {
246 String[] result = new String[addrs.size()];
248 for (InetAddress addr : addrs) {
249 result[i++] = addr.getHostAddress();