NetUtil.java
/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you 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:
*
* https://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 io.netty.util;
import io.netty.util.NetUtilInitializations.NetworkIfaceAndInetAddress;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.StringUtil;
import io.netty.util.internal.SystemPropertyUtil;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.NetworkInterface;
import java.net.UnknownHostException;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Arrays;
import java.util.Collection;
import static io.netty.util.AsciiString.indexOf;
/**
* A class that holds a number of network-related constants.
* <p/>
* This class borrowed some of its methods from a modified fork of the
* <a href="https://svn.apache.org/repos/asf/harmony/enhanced/java/branches/java6/classlib/modules/luni/
* src/main/java/org/apache/harmony/luni/util/Inet6Util.java">Inet6Util class</a> which was part of Apache Harmony.
*/
public final class NetUtil {
/**
* The {@link Inet4Address} that represents the IPv4 loopback address '127.0.0.1'
*/
public static final Inet4Address LOCALHOST4;
/**
* The {@link Inet6Address} that represents the IPv6 loopback address '::1'
*/
public static final Inet6Address LOCALHOST6;
/**
* The {@link InetAddress} that represents the loopback address. If IPv6 stack is available, it will refer to
* {@link #LOCALHOST6}. Otherwise, {@link #LOCALHOST4}.
*/
public static final InetAddress LOCALHOST;
/**
* The loopback {@link NetworkInterface} of the current machine
*/
public static final NetworkInterface LOOPBACK_IF;
/**
* An unmodifiable Collection of all the interfaces on this machine.
*/
public static final Collection<NetworkInterface> NETWORK_INTERFACES;
/**
* The SOMAXCONN value of the current machine. If failed to get the value, {@code 200} is used as a
* default value for Windows and {@code 128} for others.
*/
public static final int SOMAXCONN;
/**
* This defines how many words (represented as ints) are needed to represent an IPv6 address
*/
private static final int IPV6_WORD_COUNT = 8;
/**
* The maximum number of characters for an IPV6 string with no scope
*/
private static final int IPV6_MAX_CHAR_COUNT = 39;
/**
* Number of bytes needed to represent an IPV6 value
*/
private static final int IPV6_BYTE_COUNT = 16;
/**
* Maximum amount of value adding characters in between IPV6 separators
*/
private static final int IPV6_MAX_CHAR_BETWEEN_SEPARATOR = 4;
/**
* Minimum number of separators that must be present in an IPv6 string
*/
private static final int IPV6_MIN_SEPARATORS = 2;
/**
* Maximum number of separators that must be present in an IPv6 string
*/
private static final int IPV6_MAX_SEPARATORS = 8;
/**
* Maximum amount of value adding characters in between IPV4 separators
*/
private static final int IPV4_MAX_CHAR_BETWEEN_SEPARATOR = 3;
/**
* Number of separators that must be present in an IPv4 string
*/
private static final int IPV4_SEPARATORS = 3;
/**
* {@code true} if IPv4 should be used even if the system supports both IPv4 and IPv6.
*/
private static final boolean IPV4_PREFERRED = SystemPropertyUtil.getBoolean("java.net.preferIPv4Stack", false);
/**
* {@code true} if an IPv6 address should be preferred when a host has both an IPv4 address and an IPv6 address.
*/
private static final boolean IPV6_ADDRESSES_PREFERRED;
/**
* The logger being used by this class
*/
private static final InternalLogger logger = InternalLoggerFactory.getInstance(NetUtil.class);
static {
String prefer = SystemPropertyUtil.get("java.net.preferIPv6Addresses", "false");
if ("true".equalsIgnoreCase(prefer.trim())) {
IPV6_ADDRESSES_PREFERRED = true;
} else {
// Let's just use false in this case as only true is "forcing" ipv6.
IPV6_ADDRESSES_PREFERRED = false;
}
logger.debug("-Djava.net.preferIPv4Stack: {}", IPV4_PREFERRED);
logger.debug("-Djava.net.preferIPv6Addresses: {}", prefer);
NETWORK_INTERFACES = NetUtilInitializations.networkInterfaces();
// Create IPv4 loopback address.
LOCALHOST4 = NetUtilInitializations.createLocalhost4();
// Create IPv6 loopback address.
LOCALHOST6 = NetUtilInitializations.createLocalhost6();
NetworkIfaceAndInetAddress loopback =
NetUtilInitializations.determineLoopback(NETWORK_INTERFACES, LOCALHOST4, LOCALHOST6);
LOOPBACK_IF = loopback.iface();
LOCALHOST = loopback.address();
// As a SecurityManager may prevent reading the somaxconn file we wrap this in a privileged block.
//
// See https://github.com/netty/netty/issues/3680
SOMAXCONN = AccessController.doPrivileged(new SoMaxConnAction());
}
private static final class SoMaxConnAction implements PrivilegedAction<Integer> {
@Override
public Integer run() {
// Determine the default somaxconn (server socket backlog) value of the platform.
// The known defaults:
// - Windows NT Server 4.0+: 200
// - Linux and Mac OS X: 128
int somaxconn = PlatformDependent.isWindows() ? 200 : 128;
File file = new File("/proc/sys/net/core/somaxconn");
BufferedReader in = null;
try {
// file.exists() may throw a SecurityException if a SecurityManager is used, so execute it in the
// try / catch block.
// See https://github.com/netty/netty/issues/4936
if (file.exists()) {
in = new BufferedReader(new FileReader(file));
somaxconn = Integer.parseInt(in.readLine());
if (logger.isDebugEnabled()) {
logger.debug("{}: {}", file, somaxconn);
}
} else {
// Try to get from sysctl
Integer tmp = null;
if (SystemPropertyUtil.getBoolean("io.netty.net.somaxconn.trySysctl", false)) {
tmp = sysctlGetInt("kern.ipc.somaxconn");
if (tmp == null) {
tmp = sysctlGetInt("kern.ipc.soacceptqueue");
if (tmp != null) {
somaxconn = tmp;
}
} else {
somaxconn = tmp;
}
}
if (tmp == null) {
logger.debug("Failed to get SOMAXCONN from sysctl and file {}. Default: {}", file,
somaxconn);
}
}
} catch (Exception e) {
if (logger.isDebugEnabled()) {
logger.debug("Failed to get SOMAXCONN from sysctl and file {}. Default: {}",
file, somaxconn, e);
}
} finally {
if (in != null) {
try {
in.close();
} catch (Exception e) {
// Ignored.
}
}
}
return somaxconn;
}
}
/**
* This will execute <a href ="https://www.freebsd.org/cgi/man.cgi?sysctl(8)">sysctl</a> with the {@code sysctlKey}
* which is expected to return the numeric value for for {@code sysctlKey}.
* @param sysctlKey The key which the return value corresponds to.
* @return The <a href ="https://www.freebsd.org/cgi/man.cgi?sysctl(8)">sysctl</a> value for {@code sysctlKey}.
*/
private static Integer sysctlGetInt(String sysctlKey) throws IOException {
Process process = new ProcessBuilder("sysctl", sysctlKey).start();
try {
// Suppress warnings about resource leaks since the buffered reader is closed below
InputStream is = process.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
try {
String line = br.readLine();
if (line != null && line.startsWith(sysctlKey)) {
for (int i = line.length() - 1; i > sysctlKey.length(); --i) {
if (!Character.isDigit(line.charAt(i))) {
return Integer.valueOf(line.substring(i + 1));
}
}
}
return null;
} finally {
br.close();
}
} finally {
// No need of 'null' check because we're initializing
// the Process instance in first line. Any exception
// raised will directly lead to throwable.
process.destroy();
}
}
/**
* Returns {@code true} if IPv4 should be used even if the system supports both IPv4 and IPv6. Setting this
* property to {@code true} will disable IPv6 support. The default value of this property is {@code false}.
*
* @see <a href="https://docs.oracle.com/javase/8/docs/api/java/net/doc-files/net-properties.html">Java SE
* networking properties</a>
*/
public static boolean isIpV4StackPreferred() {
return IPV4_PREFERRED;
}
/**
* Returns {@code true} if an IPv6 address should be preferred when a host has both an IPv4 address and an IPv6
* address. The default value of this property is {@code false}.
*
* @see <a href="https://docs.oracle.com/javase/8/docs/api/java/net/doc-files/net-properties.html">Java SE
* networking properties</a>
*/
public static boolean isIpV6AddressesPreferred() {
return IPV6_ADDRESSES_PREFERRED;
}
/**
* Creates an byte[] based on an ipAddressString. No error handling is performed here.
*/
public static byte[] createByteArrayFromIpAddressString(String ipAddressString) {
if (isValidIpV4Address(ipAddressString)) {
return validIpV4ToBytes(ipAddressString);
}
if (isValidIpV6Address(ipAddressString)) {
if (ipAddressString.charAt(0) == '[') {
ipAddressString = ipAddressString.substring(1, ipAddressString.length() - 1);
}
int percentPos = ipAddressString.indexOf('%');
if (percentPos >= 0) {
ipAddressString = ipAddressString.substring(0, percentPos);
}
return getIPv6ByName(ipAddressString, true);
}
return null;
}
/**
* Creates an {@link InetAddress} based on an ipAddressString or might return null if it can't be parsed.
* No error handling is performed here.
*/
public static InetAddress createInetAddressFromIpAddressString(String ipAddressString) {
if (isValidIpV4Address(ipAddressString)) {
byte[] bytes = validIpV4ToBytes(ipAddressString);
try {
return InetAddress.getByAddress(bytes);
} catch (UnknownHostException e) {
// Should never happen!
throw new IllegalStateException(e);
}
}
if (isValidIpV6Address(ipAddressString)) {
if (ipAddressString.charAt(0) == '[') {
ipAddressString = ipAddressString.substring(1, ipAddressString.length() - 1);
}
int percentPos = ipAddressString.indexOf('%');
if (percentPos >= 0) {
try {
int scopeId = Integer.parseInt(ipAddressString.substring(percentPos + 1));
ipAddressString = ipAddressString.substring(0, percentPos);
byte[] bytes = getIPv6ByName(ipAddressString, true);
if (bytes == null) {
return null;
}
try {
return Inet6Address.getByAddress(null, bytes, scopeId);
} catch (UnknownHostException e) {
// Should never happen!
throw new IllegalStateException(e);
}
} catch (NumberFormatException e) {
return null;
}
}
byte[] bytes = getIPv6ByName(ipAddressString, true);
if (bytes == null) {
return null;
}
try {
return InetAddress.getByAddress(bytes);
} catch (UnknownHostException e) {
// Should never happen!
throw new IllegalStateException(e);
}
}
return null;
}
private static int decimalDigit(String str, int pos) {
return str.charAt(pos) - '0';
}
private static byte ipv4WordToByte(String ip, int from, int toExclusive) {
int ret = decimalDigit(ip, from);
from++;
if (from == toExclusive) {
return (byte) ret;
}
ret = ret * 10 + decimalDigit(ip, from);
from++;
if (from == toExclusive) {
return (byte) ret;
}
return (byte) (ret * 10 + decimalDigit(ip, from));
}
// visible for tests
static byte[] validIpV4ToBytes(String ip) {
int i;
return new byte[] {
ipv4WordToByte(ip, 0, i = ip.indexOf('.', 1)),
ipv4WordToByte(ip, i + 1, i = ip.indexOf('.', i + 2)),
ipv4WordToByte(ip, i + 1, i = ip.indexOf('.', i + 2)),
ipv4WordToByte(ip, i + 1, ip.length())
};
}
/**
* Convert {@link Inet4Address} into {@code int}
*/
public static int ipv4AddressToInt(Inet4Address ipAddress) {
byte[] octets = ipAddress.getAddress();
return (octets[0] & 0xff) << 24 |
(octets[1] & 0xff) << 16 |
(octets[2] & 0xff) << 8 |
octets[3] & 0xff;
}
/**
* Converts a 32-bit integer into an IPv4 address.
*/
public static String intToIpAddress(int i) {
StringBuilder buf = new StringBuilder(15);
buf.append(i >> 24 & 0xff);
buf.append('.');
buf.append(i >> 16 & 0xff);
buf.append('.');
buf.append(i >> 8 & 0xff);
buf.append('.');
buf.append(i & 0xff);
return buf.toString();
}
/**
* Converts 4-byte or 16-byte data into an IPv4 or IPv6 string respectively.
*
* @throws IllegalArgumentException
* if {@code length} is not {@code 4} nor {@code 16}
*/
public static String bytesToIpAddress(byte[] bytes) {
return bytesToIpAddress(bytes, 0, bytes.length);
}
/**
* Converts 4-byte or 16-byte data into an IPv4 or IPv6 string respectively.
*
* @throws IllegalArgumentException
* if {@code length} is not {@code 4} nor {@code 16}
*/
public static String bytesToIpAddress(byte[] bytes, int offset, int length) {
switch (length) {
case 4: {
return new StringBuilder(15)
.append(bytes[offset] & 0xff)
.append('.')
.append(bytes[offset + 1] & 0xff)
.append('.')
.append(bytes[offset + 2] & 0xff)
.append('.')
.append(bytes[offset + 3] & 0xff).toString();
}
case 16:
return toAddressString(bytes, offset, false);
default:
throw new IllegalArgumentException("length: " + length + " (expected: 4 or 16)");
}
}
public static boolean isValidIpV6Address(String ip) {
return isValidIpV6Address((CharSequence) ip);
}
public static boolean isValidIpV6Address(CharSequence ip) {
int end = ip.length();
if (end < 2) {
return false;
}
// strip "[]"
int start;
char c = ip.charAt(0);
if (c == '[') {
end--;
if (ip.charAt(end) != ']') {
// must have a close ]
return false;
}
start = 1;
c = ip.charAt(1);
} else {
start = 0;
}
int colons;
int compressBegin;
if (c == ':') {
// an IPv6 address can start with "::" or with a number
if (ip.charAt(start + 1) != ':') {
return false;
}
colons = 2;
compressBegin = start;
start += 2;
} else {
colons = 0;
compressBegin = -1;
}
int wordLen = 0;
loop:
for (int i = start; i < end; i++) {
c = ip.charAt(i);
if (isValidHexChar(c)) {
if (wordLen < 4) {
wordLen++;
continue;
}
return false;
}
switch (c) {
case ':':
if (colons > 7) {
return false;
}
if (ip.charAt(i - 1) == ':') {
if (compressBegin >= 0) {
return false;
}
compressBegin = i - 1;
} else {
wordLen = 0;
}
colons++;
break;
case '.':
// case for the last 32-bits represented as IPv4 x:x:x:x:x:x:d.d.d.d
// check a normal case (6 single colons)
if (compressBegin < 0 && colons != 6 ||
// a special case ::1:2:3:4:5:d.d.d.d allows 7 colons with an
// IPv4 ending, otherwise 7 :'s is bad
(colons == 7 && compressBegin >= start || colons > 7)) {
return false;
}
// Verify this address is of the correct structure to contain an IPv4 address.
// It must be IPv4-Mapped or IPv4-Compatible
// (see https://tools.ietf.org/html/rfc4291#section-2.5.5).
int ipv4Start = i - wordLen;
int j = ipv4Start - 2; // index of character before the previous ':'.
if (isValidIPv4MappedChar(ip.charAt(j))) {
if (!isValidIPv4MappedChar(ip.charAt(j - 1)) ||
!isValidIPv4MappedChar(ip.charAt(j - 2)) ||
!isValidIPv4MappedChar(ip.charAt(j - 3))) {
return false;
}
j -= 5;
}
for (; j >= start; --j) {
char tmpChar = ip.charAt(j);
if (tmpChar != '0' && tmpChar != ':') {
return false;
}
}
// 7 - is minimum IPv4 address length
int ipv4End = indexOf(ip, '%', ipv4Start + 7);
if (ipv4End < 0) {
ipv4End = end;
}
return isValidIpV4Address(ip, ipv4Start, ipv4End);
case '%':
// strip the interface name/index after the percent sign
end = i;
break loop;
default:
return false;
}
}
// normal case without compression
if (compressBegin < 0) {
return colons == 7 && wordLen > 0;
}
return compressBegin + 2 == end ||
// 8 colons is valid only if compression in start or end
wordLen > 0 && (colons < 8 || compressBegin <= start);
}
private static boolean isValidIpV4Word(CharSequence word, int from, int toExclusive) {
int len = toExclusive - from;
char c0, c1, c2;
if (len < 1 || len > 3 || (c0 = word.charAt(from)) < '0') {
return false;
}
if (len == 3) {
return (c1 = word.charAt(from + 1)) >= '0' &&
(c2 = word.charAt(from + 2)) >= '0' &&
(c0 <= '1' && c1 <= '9' && c2 <= '9' ||
c0 == '2' && c1 <= '5' && (c2 <= '5' || c1 < '5' && c2 <= '9'));
}
return c0 <= '9' && (len == 1 || isValidNumericChar(word.charAt(from + 1)));
}
private static boolean isValidHexChar(char c) {
return c >= '0' && c <= '9' || c >= 'A' && c <= 'F' || c >= 'a' && c <= 'f';
}
private static boolean isValidNumericChar(char c) {
return c >= '0' && c <= '9';
}
private static boolean isValidIPv4MappedChar(char c) {
return c == 'f' || c == 'F';
}
private static boolean isValidIPv4MappedSeparators(byte b0, byte b1, boolean mustBeZero) {
// We allow IPv4 Mapped (https://tools.ietf.org/html/rfc4291#section-2.5.5.1)
// and IPv4 compatible (https://tools.ietf.org/html/rfc4291#section-2.5.5.1).
// The IPv4 compatible is deprecated, but it allows parsing of plain IPv4 addressed into IPv6-Mapped addresses.
return b0 == b1 && (b0 == 0 || !mustBeZero && b1 == -1);
}
private static boolean isValidIPv4Mapped(byte[] bytes, int currentIndex, int compressBegin, int compressLength) {
final boolean mustBeZero = compressBegin + compressLength >= 14;
return currentIndex <= 12 && currentIndex >= 2 && (!mustBeZero || compressBegin < 12) &&
isValidIPv4MappedSeparators(bytes[currentIndex - 1], bytes[currentIndex - 2], mustBeZero) &&
PlatformDependent.isZero(bytes, 0, currentIndex - 3);
}
/**
* Takes a {@link CharSequence} and parses it to see if it is a valid IPV4 address.
*
* @return true, if the string represents an IPV4 address in dotted
* notation, false otherwise
*/
public static boolean isValidIpV4Address(CharSequence ip) {
return isValidIpV4Address(ip, 0, ip.length());
}
/**
* Takes a {@link String} and parses it to see if it is a valid IPV4 address.
*
* @return true, if the string represents an IPV4 address in dotted
* notation, false otherwise
*/
public static boolean isValidIpV4Address(String ip) {
return isValidIpV4Address(ip, 0, ip.length());
}
private static boolean isValidIpV4Address(CharSequence ip, int from, int toExcluded) {
return ip instanceof String ? isValidIpV4Address((String) ip, from, toExcluded) :
ip instanceof AsciiString ? isValidIpV4Address((AsciiString) ip, from, toExcluded) :
isValidIpV4Address0(ip, from, toExcluded);
}
@SuppressWarnings("DuplicateBooleanBranch")
private static boolean isValidIpV4Address(String ip, int from, int toExcluded) {
int len = toExcluded - from;
int i;
return len <= 15 && len >= 7 &&
(i = ip.indexOf('.', from + 1)) > 0 && isValidIpV4Word(ip, from, i) &&
(i = ip.indexOf('.', from = i + 2)) > 0 && isValidIpV4Word(ip, from - 1, i) &&
(i = ip.indexOf('.', from = i + 2)) > 0 && isValidIpV4Word(ip, from - 1, i) &&
isValidIpV4Word(ip, i + 1, toExcluded);
}
@SuppressWarnings("DuplicateBooleanBranch")
private static boolean isValidIpV4Address(AsciiString ip, int from, int toExcluded) {
int len = toExcluded - from;
int i;
return len <= 15 && len >= 7 &&
(i = ip.indexOf('.', from + 1)) > 0 && isValidIpV4Word(ip, from, i) &&
(i = ip.indexOf('.', from = i + 2)) > 0 && isValidIpV4Word(ip, from - 1, i) &&
(i = ip.indexOf('.', from = i + 2)) > 0 && isValidIpV4Word(ip, from - 1, i) &&
isValidIpV4Word(ip, i + 1, toExcluded);
}
@SuppressWarnings("DuplicateBooleanBranch")
private static boolean isValidIpV4Address0(CharSequence ip, int from, int toExcluded) {
int len = toExcluded - from;
int i;
return len <= 15 && len >= 7 &&
(i = indexOf(ip, '.', from + 1)) > 0 && isValidIpV4Word(ip, from, i) &&
(i = indexOf(ip, '.', from = i + 2)) > 0 && isValidIpV4Word(ip, from - 1, i) &&
(i = indexOf(ip, '.', from = i + 2)) > 0 && isValidIpV4Word(ip, from - 1, i) &&
isValidIpV4Word(ip, i + 1, toExcluded);
}
/**
* Returns the {@link Inet6Address} representation of a {@link CharSequence} IP address.
* <p>
* This method will treat all IPv4 type addresses as "IPv4 mapped" (see {@link #getByName(CharSequence, boolean)})
* @param ip {@link CharSequence} IP address to be converted to a {@link Inet6Address}
* @return {@link Inet6Address} representation of the {@code ip} or {@code null} if not a valid IP address.
*/
public static Inet6Address getByName(CharSequence ip) {
return getByName(ip, true);
}
/**
* Returns the {@link Inet6Address} representation of a {@link CharSequence} IP address.
* <p>
* The {@code ipv4Mapped} parameter specifies how IPv4 addresses should be treated.
* "IPv4 mapped" format as
* defined in <a href="https://tools.ietf.org/html/rfc4291#section-2.5.5">rfc 4291 section 2</a> is supported.
* @param ip {@link CharSequence} IP address to be converted to a {@link Inet6Address}
* @param ipv4Mapped
* <ul>
* <li>{@code true} To allow IPv4 mapped inputs to be translated into {@link Inet6Address}</li>
* <li>{@code false} Consider IPv4 mapped addresses as invalid.</li>
* </ul>
* @return {@link Inet6Address} representation of the {@code ip} or {@code null} if not a valid IP address.
*/
public static Inet6Address getByName(CharSequence ip, boolean ipv4Mapped) {
byte[] bytes = getIPv6ByName(ip, ipv4Mapped);
if (bytes == null) {
return null;
}
try {
return Inet6Address.getByAddress(null, bytes, -1);
} catch (UnknownHostException e) {
throw new RuntimeException(e); // Should never happen
}
}
/**
* Returns the byte array representation of a {@link CharSequence} IP address.
* <p>
* The {@code ipv4Mapped} parameter specifies how IPv4 addresses should be treated.
* "IPv4 mapped" format as
* defined in <a href="https://tools.ietf.org/html/rfc4291#section-2.5.5">rfc 4291 section 2</a> is supported.
* @param ip {@link CharSequence} IP address to be converted to a {@link Inet6Address}
* @param ipv4Mapped
* <ul>
* <li>{@code true} To allow IPv4 mapped inputs to be translated into {@link Inet6Address}</li>
* <li>{@code false} Consider IPv4 mapped addresses as invalid.</li>
* </ul>
* @return byte array representation of the {@code ip} or {@code null} if not a valid IP address.
*/
// visible for test
static byte[] getIPv6ByName(CharSequence ip, boolean ipv4Mapped) {
final byte[] bytes = new byte[IPV6_BYTE_COUNT];
final int ipLength = ip.length();
int compressBegin = 0;
int compressLength = 0;
int currentIndex = 0;
int value = 0;
int begin = -1;
int i = 0;
int ipv6Separators = 0;
int ipv4Separators = 0;
int tmp;
for (; i < ipLength; ++i) {
final char c = ip.charAt(i);
switch (c) {
case ':':
++ipv6Separators;
if (i - begin > IPV6_MAX_CHAR_BETWEEN_SEPARATOR ||
ipv4Separators > 0 || ipv6Separators > IPV6_MAX_SEPARATORS ||
currentIndex + 1 >= bytes.length) {
return null;
}
value <<= (IPV6_MAX_CHAR_BETWEEN_SEPARATOR - (i - begin)) << 2;
if (compressLength > 0) {
compressLength -= 2;
}
// The value integer holds at most 4 bytes from right (most significant) to left (least significant).
// The following bit shifting is used to extract and re-order the individual bytes to achieve a
// left (most significant) to right (least significant) ordering.
bytes[currentIndex++] = (byte) (((value & 0xf) << 4) | ((value >> 4) & 0xf));
bytes[currentIndex++] = (byte) ((((value >> 8) & 0xf) << 4) | ((value >> 12) & 0xf));
tmp = i + 1;
if (tmp < ipLength && ip.charAt(tmp) == ':') {
++tmp;
if (compressBegin != 0 || (tmp < ipLength && ip.charAt(tmp) == ':')) {
return null;
}
++ipv6Separators;
compressBegin = currentIndex;
compressLength = bytes.length - compressBegin - 2;
++i;
}
value = 0;
begin = -1;
break;
case '.':
++ipv4Separators;
tmp = i - begin; // tmp is the length of the current segment.
if (tmp > IPV4_MAX_CHAR_BETWEEN_SEPARATOR
|| begin < 0
|| ipv4Separators > IPV4_SEPARATORS
|| (ipv6Separators > 0 && (currentIndex + compressLength < 12))
|| i + 1 >= ipLength
|| currentIndex >= bytes.length
|| ipv4Separators == 1 &&
// We also parse pure IPv4 addresses as IPv4-Mapped for ease of use.
((!ipv4Mapped || currentIndex != 0 && !isValidIPv4Mapped(bytes, currentIndex,
compressBegin, compressLength)) ||
(tmp == 3 && (!isValidNumericChar(ip.charAt(i - 1)) ||
!isValidNumericChar(ip.charAt(i - 2)) ||
!isValidNumericChar(ip.charAt(i - 3))) ||
tmp == 2 && (!isValidNumericChar(ip.charAt(i - 1)) ||
!isValidNumericChar(ip.charAt(i - 2))) ||
tmp == 1 && !isValidNumericChar(ip.charAt(i - 1))))) {
return null;
}
value <<= (IPV4_MAX_CHAR_BETWEEN_SEPARATOR - tmp) << 2;
// The value integer holds at most 3 bytes from right (most significant) to left (least significant).
// The following bit shifting is to restructure the bytes to be left (most significant) to
// right (least significant) while also accounting for each IPv4 digit is base 10.
begin = (value & 0xf) * 100 + ((value >> 4) & 0xf) * 10 + ((value >> 8) & 0xf);
if (begin > 255) {
return null;
}
bytes[currentIndex++] = (byte) begin;
value = 0;
begin = -1;
break;
default:
if (!isValidHexChar(c) || (ipv4Separators > 0 && !isValidNumericChar(c))) {
return null;
}
if (begin < 0) {
begin = i;
} else if (i - begin > IPV6_MAX_CHAR_BETWEEN_SEPARATOR) {
return null;
}
// The value is treated as a sort of array of numbers because we are dealing with
// at most 4 consecutive bytes we can use bit shifting to accomplish this.
// The most significant byte will be encountered first, and reside in the right most
// position of the following integer
value += StringUtil.decodeHexNibble(c) << ((i - begin) << 2);
break;
}
}
final boolean isCompressed = compressBegin > 0;
// Finish up last set of data that was accumulated in the loop (or before the loop)
if (ipv4Separators > 0) {
if (begin > 0 && i - begin > IPV4_MAX_CHAR_BETWEEN_SEPARATOR ||
ipv4Separators != IPV4_SEPARATORS ||
currentIndex >= bytes.length) {
return null;
}
if (!(ipv6Separators == 0 || ipv6Separators >= IPV6_MIN_SEPARATORS &&
(!isCompressed && (ipv6Separators == 6 && ip.charAt(0) != ':') ||
isCompressed && (ipv6Separators < IPV6_MAX_SEPARATORS &&
(ip.charAt(0) != ':' || compressBegin <= 2))))) {
return null;
}
value <<= (IPV4_MAX_CHAR_BETWEEN_SEPARATOR - (i - begin)) << 2;
// The value integer holds at most 3 bytes from right (most significant) to left (least significant).
// The following bit shifting is to restructure the bytes to be left (most significant) to
// right (least significant) while also accounting for each IPv4 digit is base 10.
begin = (value & 0xf) * 100 + ((value >> 4) & 0xf) * 10 + ((value >> 8) & 0xf);
if (begin > 255) {
return null;
}
bytes[currentIndex++] = (byte) begin;
} else {
tmp = ipLength - 1;
if (begin > 0 && i - begin > IPV6_MAX_CHAR_BETWEEN_SEPARATOR ||
ipv6Separators < IPV6_MIN_SEPARATORS ||
!isCompressed && (ipv6Separators + 1 != IPV6_MAX_SEPARATORS ||
ip.charAt(0) == ':' || ip.charAt(tmp) == ':') ||
isCompressed && (ipv6Separators > IPV6_MAX_SEPARATORS ||
(ipv6Separators == IPV6_MAX_SEPARATORS &&
(compressBegin <= 2 && ip.charAt(0) != ':' ||
compressBegin >= 14 && ip.charAt(tmp) != ':'))) ||
currentIndex + 1 >= bytes.length ||
begin < 0 && ip.charAt(tmp - 1) != ':' ||
compressBegin > 2 && ip.charAt(0) == ':') {
return null;
}
if (begin >= 0 && i - begin <= IPV6_MAX_CHAR_BETWEEN_SEPARATOR) {
value <<= (IPV6_MAX_CHAR_BETWEEN_SEPARATOR - (i - begin)) << 2;
}
// The value integer holds at most 4 bytes from right (most significant) to left (least significant).
// The following bit shifting is used to extract and re-order the individual bytes to achieve a
// left (most significant) to right (least significant) ordering.
bytes[currentIndex++] = (byte) (((value & 0xf) << 4) | ((value >> 4) & 0xf));
bytes[currentIndex++] = (byte) ((((value >> 8) & 0xf) << 4) | ((value >> 12) & 0xf));
}
if (currentIndex < bytes.length) {
int toBeCopiedLength = currentIndex - compressBegin;
int targetIndex = bytes.length - toBeCopiedLength;
System.arraycopy(bytes, compressBegin, bytes, targetIndex, toBeCopiedLength);
// targetIndex is also the `toIndex` to fill 0
Arrays.fill(bytes, compressBegin, targetIndex, (byte) 0);
}
if (ipv4Separators > 0) {
// We only support IPv4-Mapped addresses [1] because IPv4-Compatible addresses are deprecated [2].
// [1] https://tools.ietf.org/html/rfc4291#section-2.5.5.2
// [2] https://tools.ietf.org/html/rfc4291#section-2.5.5.1
bytes[10] = bytes[11] = (byte) 0xff;
}
return bytes;
}
/**
* Returns the {@link String} representation of an {@link InetSocketAddress}.
* <p>
* The output does not include Scope ID.
* @param addr {@link InetSocketAddress} to be converted to an address string
* @return {@code String} containing the text-formatted IP address
*/
public static String toSocketAddressString(InetSocketAddress addr) {
String port = String.valueOf(addr.getPort());
final StringBuilder sb;
if (addr.isUnresolved()) {
String hostname = getHostname(addr);
sb = newSocketAddressStringBuilder(hostname, port, !isValidIpV6Address(hostname));
} else {
InetAddress address = addr.getAddress();
String hostString = toAddressString(address);
sb = newSocketAddressStringBuilder(hostString, port, address instanceof Inet4Address);
}
return sb.append(':').append(port).toString();
}
/**
* Returns the {@link String} representation of a host port combo.
*/
public static String toSocketAddressString(String host, int port) {
String portStr = String.valueOf(port);
return newSocketAddressStringBuilder(
host, portStr, !isValidIpV6Address(host)).append(':').append(portStr).toString();
}
private static StringBuilder newSocketAddressStringBuilder(String host, String port, boolean ipv4) {
int hostLen = host.length();
if (ipv4) {
// Need to include enough space for hostString:port.
return new StringBuilder(hostLen + 1 + port.length()).append(host);
}
// Need to include enough space for [hostString]:port.
StringBuilder stringBuilder = new StringBuilder(hostLen + 3 + port.length());
if (hostLen > 1 && host.charAt(0) == '[' && host.charAt(hostLen - 1) == ']') {
return stringBuilder.append(host);
}
return stringBuilder.append('[').append(host).append(']');
}
/**
* Returns the {@link String} representation of an {@link InetAddress}.
* <ul>
* <li>Inet4Address results are identical to {@link InetAddress#getHostAddress()}</li>
* <li>Inet6Address results adhere to
* <a href="https://tools.ietf.org/html/rfc5952#section-4">rfc 5952 section 4</a></li>
* </ul>
* <p>
* The output does not include Scope ID.
* @param ip {@link InetAddress} to be converted to an address string
* @return {@code String} containing the text-formatted IP address
*/
public static String toAddressString(InetAddress ip) {
return toAddressString(ip, false);
}
/**
* Returns the {@link String} representation of an {@link InetAddress}.
* <ul>
* <li>Inet4Address results are identical to {@link InetAddress#getHostAddress()}</li>
* <li>Inet6Address results adhere to
* <a href="https://tools.ietf.org/html/rfc5952#section-4">rfc 5952 section 4</a> if
* {@code ipv4Mapped} is false. If {@code ipv4Mapped} is true then "IPv4 mapped" format
* from <a href="https://tools.ietf.org/html/rfc4291#section-2.5.5">rfc 4291 section 2</a> will be supported.
* The compressed result will always obey the compression rules defined in
* <a href="https://tools.ietf.org/html/rfc5952#section-4">rfc 5952 section 4</a></li>
* </ul>
* <p>
* The output does not include Scope ID.
* @param ip {@link InetAddress} to be converted to an address string
* @param ipv4Mapped
* <ul>
* <li>{@code true} to stray from strict rfc 5952 and support the "IPv4 mapped" format
* defined in <a href="https://tools.ietf.org/html/rfc4291#section-2.5.5">rfc 4291 section 2</a> while still
* following the updated guidelines in
* <a href="https://tools.ietf.org/html/rfc5952#section-4">rfc 5952 section 4</a></li>
* <li>{@code false} to strictly follow rfc 5952</li>
* </ul>
* @return {@code String} containing the text-formatted IP address
*/
public static String toAddressString(InetAddress ip, boolean ipv4Mapped) {
if (ip instanceof Inet4Address) {
return ip.getHostAddress();
}
if (!(ip instanceof Inet6Address)) {
throw new IllegalArgumentException("Unhandled type: " + ip);
}
return toAddressString(ip.getAddress(), 0, ipv4Mapped);
}
private static String toAddressString(byte[] bytes, int offset, boolean ipv4Mapped) {
final int[] words = new int[IPV6_WORD_COUNT];
for (int i = 0; i < words.length; ++i) {
int idx = (i << 1) + offset;
words[i] = ((bytes[idx] & 0xff) << 8) | (bytes[idx + 1] & 0xff);
}
// Find longest run of 0s, tie goes to first found instance
int currentStart = -1;
int currentLength;
int shortestStart = -1;
int shortestLength = 0;
for (int i = 0; i < words.length; ++i) {
if (words[i] == 0) {
if (currentStart < 0) {
currentStart = i;
}
} else if (currentStart >= 0) {
currentLength = i - currentStart;
if (currentLength > shortestLength) {
shortestStart = currentStart;
shortestLength = currentLength;
}
currentStart = -1;
}
}
// If the array ends on a streak of zeros, make sure we account for it
if (currentStart >= 0) {
currentLength = words.length - currentStart;
if (currentLength > shortestLength) {
shortestStart = currentStart;
shortestLength = currentLength;
}
}
// Ignore the longest streak if it is only 1 long
if (shortestLength == 1) {
shortestLength = 0;
shortestStart = -1;
}
// Translate to string taking into account longest consecutive 0s
final int shortestEnd = shortestStart + shortestLength;
final StringBuilder b = new StringBuilder(IPV6_MAX_CHAR_COUNT);
if (shortestEnd < 0) { // Optimization when there is no compressing needed
b.append(Integer.toHexString(words[0]));
for (int i = 1; i < words.length; ++i) {
b.append(':');
b.append(Integer.toHexString(words[i]));
}
} else { // General case that can handle compressing (and not compressing)
// Loop unroll the first index (so we don't constantly check i==0 cases in loop)
final boolean isIpv4Mapped;
if (inRangeEndExclusive(0, shortestStart, shortestEnd)) {
b.append("::");
isIpv4Mapped = ipv4Mapped && (shortestEnd == 5 && words[5] == 0xffff);
} else {
b.append(Integer.toHexString(words[0]));
isIpv4Mapped = false;
}
for (int i = 1; i < words.length; ++i) {
if (!inRangeEndExclusive(i, shortestStart, shortestEnd)) {
if (!inRangeEndExclusive(i - 1, shortestStart, shortestEnd)) {
// If the last index was not part of the shortened sequence
if (!isIpv4Mapped || i == 6) {
b.append(':');
} else {
b.append('.');
}
}
if (isIpv4Mapped && i > 5) {
b.append(words[i] >> 8);
b.append('.');
b.append(words[i] & 0xff);
} else {
b.append(Integer.toHexString(words[i]));
}
} else if (!inRangeEndExclusive(i - 1, shortestStart, shortestEnd)) {
// If we are in the shortened sequence and the last index was not
b.append("::");
}
}
}
return b.toString();
}
/**
* Returns {@link InetSocketAddress#getHostString()} if Java >= 7,
* or {@link InetSocketAddress#getHostName()} otherwise.
* @param addr The address
* @return the host string
*/
public static String getHostname(InetSocketAddress addr) {
return PlatformDependent.javaVersion() >= 7 ? addr.getHostString() : addr.getHostName();
}
/**
* Does a range check on {@code value} if is within {@code start} (inclusive) and {@code end} (exclusive).
* @param value The value to checked if is within {@code start} (inclusive) and {@code end} (exclusive)
* @param start The start of the range (inclusive)
* @param end The end of the range (exclusive)
* @return
* <ul>
* <li>{@code true} if {@code value} if is within {@code start} (inclusive) and {@code end} (exclusive)</li>
* <li>{@code false} otherwise</li>
* </ul>
*/
private static boolean inRangeEndExclusive(int value, int start, int end) {
return value >= start && value < end;
}
/**
* A constructor to stop this class being constructed.
*/
private NetUtil() {
// Unused
}
}