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Diffstat (limited to 'common/framework/com/android/net/module/util/Inet4AddressUtils.java')
-rw-r--r-- | common/framework/com/android/net/module/util/Inet4AddressUtils.java | 192 |
1 files changed, 0 insertions, 192 deletions
diff --git a/common/framework/com/android/net/module/util/Inet4AddressUtils.java b/common/framework/com/android/net/module/util/Inet4AddressUtils.java deleted file mode 100644 index 87f43d51..00000000 --- a/common/framework/com/android/net/module/util/Inet4AddressUtils.java +++ /dev/null @@ -1,192 +0,0 @@ -/* - * Copyright (C) 2020 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 com.android.net.module.util; - -import java.net.Inet4Address; -import java.net.InetAddress; -import java.net.UnknownHostException; - -/** - * Collection of utilities to work with IPv4 addresses. - * @hide - */ -public class Inet4AddressUtils { - - /** - * Convert a IPv4 address from an integer to an InetAddress (0x04030201 -> 1.2.3.4) - * - * <p>This method uses the higher-order int bytes as the lower-order IPv4 address bytes, - * which is an unusual convention. Consider {@link #intToInet4AddressHTH(int)} instead. - * @param hostAddress an int coding for an IPv4 address, where higher-order int byte is - * lower-order IPv4 address byte - */ - public static Inet4Address intToInet4AddressHTL(int hostAddress) { - return intToInet4AddressHTH(Integer.reverseBytes(hostAddress)); - } - - /** - * Convert a IPv4 address from an integer to an InetAddress (0x01020304 -> 1.2.3.4) - * @param hostAddress an int coding for an IPv4 address - */ - public static Inet4Address intToInet4AddressHTH(int hostAddress) { - byte[] addressBytes = { (byte) (0xff & (hostAddress >> 24)), - (byte) (0xff & (hostAddress >> 16)), - (byte) (0xff & (hostAddress >> 8)), - (byte) (0xff & hostAddress) }; - - try { - return (Inet4Address) InetAddress.getByAddress(addressBytes); - } catch (UnknownHostException e) { - throw new AssertionError(); - } - } - - /** - * Convert an IPv4 address from an InetAddress to an integer (1.2.3.4 -> 0x01020304) - * - * <p>This conversion can help order IP addresses: considering the ordering - * 192.0.2.1 < 192.0.2.2 < ..., resulting ints will follow that ordering if read as unsigned - * integers with {@link Integer#toUnsignedLong}. - * @param inetAddr is an InetAddress corresponding to the IPv4 address - * @return the IP address as integer - */ - public static int inet4AddressToIntHTH(Inet4Address inetAddr) - throws IllegalArgumentException { - byte [] addr = inetAddr.getAddress(); - return ((addr[0] & 0xff) << 24) | ((addr[1] & 0xff) << 16) - | ((addr[2] & 0xff) << 8) | (addr[3] & 0xff); - } - - /** - * Convert a IPv4 address from an InetAddress to an integer (1.2.3.4 -> 0x04030201) - * - * <p>This method stores the higher-order IPv4 address bytes in the lower-order int bytes, - * which is an unusual convention. Consider {@link #inet4AddressToIntHTH(Inet4Address)} instead. - * @param inetAddr is an InetAddress corresponding to the IPv4 address - * @return the IP address as integer - */ - public static int inet4AddressToIntHTL(Inet4Address inetAddr) { - return Integer.reverseBytes(inet4AddressToIntHTH(inetAddr)); - } - - /** - * Convert a network prefix length to an IPv4 netmask integer (prefixLength 17 -> 0xffff8000) - * @return the IPv4 netmask as an integer - */ - public static int prefixLengthToV4NetmaskIntHTH(int prefixLength) - throws IllegalArgumentException { - if (prefixLength < 0 || prefixLength > 32) { - throw new IllegalArgumentException("Invalid prefix length (0 <= prefix <= 32)"); - } - // (int)a << b is equivalent to a << (b & 0x1f): can't shift by 32 (-1 << 32 == -1) - return prefixLength == 0 ? 0 : 0xffffffff << (32 - prefixLength); - } - - /** - * Convert a network prefix length to an IPv4 netmask integer (prefixLength 17 -> 0x0080ffff). - * - * <p>This method stores the higher-order IPv4 address bytes in the lower-order int bytes, - * which is an unusual convention. Consider {@link #prefixLengthToV4NetmaskIntHTH(int)} instead. - * @return the IPv4 netmask as an integer - */ - public static int prefixLengthToV4NetmaskIntHTL(int prefixLength) - throws IllegalArgumentException { - return Integer.reverseBytes(prefixLengthToV4NetmaskIntHTH(prefixLength)); - } - - /** - * Convert an IPv4 netmask to a prefix length, checking that the netmask is contiguous. - * @param netmask as a {@code Inet4Address}. - * @return the network prefix length - * @throws IllegalArgumentException the specified netmask was not contiguous. - * @hide - */ - public static int netmaskToPrefixLength(Inet4Address netmask) { - // inetAddressToInt returns an int in *network* byte order. - int i = inet4AddressToIntHTH(netmask); - int prefixLength = Integer.bitCount(i); - int trailingZeros = Integer.numberOfTrailingZeros(i); - if (trailingZeros != 32 - prefixLength) { - throw new IllegalArgumentException("Non-contiguous netmask: " + Integer.toHexString(i)); - } - return prefixLength; - } - - /** - * Returns the implicit netmask of an IPv4 address, as was the custom before 1993. - */ - public static int getImplicitNetmask(Inet4Address address) { - int firstByte = address.getAddress()[0] & 0xff; // Convert to an unsigned value. - if (firstByte < 128) { - return 8; - } else if (firstByte < 192) { - return 16; - } else if (firstByte < 224) { - return 24; - } else { - return 32; // Will likely not end well for other reasons. - } - } - - /** - * Get the broadcast address for a given prefix. - * - * <p>For example 192.168.0.1/24 -> 192.168.0.255 - */ - public static Inet4Address getBroadcastAddress(Inet4Address addr, int prefixLength) - throws IllegalArgumentException { - final int intBroadcastAddr = inet4AddressToIntHTH(addr) - | ~prefixLengthToV4NetmaskIntHTH(prefixLength); - return intToInet4AddressHTH(intBroadcastAddr); - } - - /** - * Get a prefix mask as Inet4Address for a given prefix length. - * - * <p>For example 20 -> 255.255.240.0 - */ - public static Inet4Address getPrefixMaskAsInet4Address(int prefixLength) - throws IllegalArgumentException { - return intToInet4AddressHTH(prefixLengthToV4NetmaskIntHTH(prefixLength)); - } - - /** - * Trim leading zeros from IPv4 address strings - * Non-v4 addresses and host names remain unchanged. - * For example, 192.168.000.010 -> 192.168.0.10 - * @param addr a string representing an ip address - * @return a string properly trimmed - */ - public static String trimAddressZeros(String addr) { - if (addr == null) return null; - String[] octets = addr.split("\\."); - if (octets.length != 4) return addr; - StringBuilder builder = new StringBuilder(16); - String result = null; - for (int i = 0; i < 4; i++) { - try { - if (octets[i].length() > 3) return addr; - builder.append(Integer.parseInt(octets[i])); - } catch (NumberFormatException e) { - return addr; - } - if (i < 3) builder.append('.'); - } - result = builder.toString(); - return result; - } -} |