com.tencent.kona.sun.net.util.IPAddressUtil Maven / Gradle / Ivy
/*
* Copyright (c) 2004, 2022, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.tencent.kona.sun.net.util;
import com.tencent.kona.sun.security.action.GetPropertyAction;
import java.io.UncheckedIOException;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.URL;
import java.nio.CharBuffer;
import java.security.AccessController;
import java.security.PrivilegedExceptionAction;
import java.security.PrivilegedActionException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
public class IPAddressUtil {
private static final int INADDR4SZ = 4;
private static final int INADDR16SZ = 16;
private static final int INT16SZ = 2;
/*
* Converts IPv4 address in its textual presentation form
* into its numeric binary form.
*
* @param src a String representing an IPv4 address in standard format
* @return a byte array representing the IPv4 numeric address
*/
@SuppressWarnings("fallthrough")
public static byte[] textToNumericFormatV4(String src)
{
byte[] res = new byte[INADDR4SZ];
long tmpValue = 0;
int currByte = 0;
boolean newOctet = true;
int len = src.length();
if (len == 0 || len > 15) {
return null;
}
/*
* When only one part is given, the value is stored directly in
* the network address without any byte rearrangement.
*
* When a two part address is supplied, the last part is
* interpreted as a 24-bit quantity and placed in the right
* most three bytes of the network address. This makes the
* two part address format convenient for specifying Class A
* network addresses as net.host.
*
* When a three part address is specified, the last part is
* interpreted as a 16-bit quantity and placed in the right
* most two bytes of the network address. This makes the
* three part address format convenient for specifying
* Class B net- work addresses as 128.net.host.
*
* When four parts are specified, each is interpreted as a
* byte of data and assigned, from left to right, to the
* four bytes of an IPv4 address.
*
* We determine and parse the leading parts, if any, as single
* byte values in one pass directly into the resulting byte[],
* then the remainder is treated as a 8-to-32-bit entity and
* translated into the remaining bytes in the array.
*/
for (int i = 0; i < len; i++) {
char c = src.charAt(i);
if (c == '.') {
if (newOctet || tmpValue < 0 || tmpValue > 0xff || currByte == 3) {
return null;
}
res[currByte++] = (byte) (tmpValue & 0xff);
tmpValue = 0;
newOctet = true;
} else {
int digit = digit(c, 10);
if (digit < 0) {
return null;
}
tmpValue *= 10;
tmpValue += digit;
newOctet = false;
}
}
if (newOctet || tmpValue < 0 || tmpValue >= (1L << ((4 - currByte) * 8))) {
return null;
}
switch (currByte) {
case 0:
res[0] = (byte) ((tmpValue >> 24) & 0xff);
case 1:
res[1] = (byte) ((tmpValue >> 16) & 0xff);
case 2:
res[2] = (byte) ((tmpValue >> 8) & 0xff);
case 3:
res[3] = (byte) ((tmpValue >> 0) & 0xff);
}
return res;
}
/**
* Validates if input string is a valid IPv4 address literal.
* If the "jdk.net.allowAmbiguousIPAddressLiterals" system property is set
* to {@code false}, or is not set then validation of the address string is performed as follows:
* If string can't be parsed by following IETF IPv4 address string literals
* formatting style rules (default one), but can be parsed by following BSD formatting
* style rules, the IPv4 address string content is treated as ambiguous and
* {@code IllegalArgumentException} is thrown.
*
* @param src input string
* @return bytes array if string is a valid IPv4 address string
* @throws IllegalArgumentException if "jdk.net.allowAmbiguousIPAddressLiterals" SP is set to
* "false" and IPv4 address string {@code "src"} is ambiguous
*/
public static byte[] validateNumericFormatV4(String src) {
byte[] parsedBytes = textToNumericFormatV4(src);
if (!ALLOW_AMBIGUOUS_IPADDRESS_LITERALS_SP_VALUE
&& parsedBytes == null && isBsdParsableV4(src)) {
throw new IllegalArgumentException("Invalid IP address literal: " + src);
}
return parsedBytes;
}
/*
* Convert IPv6 presentation level address to network order binary form.
* credit:
* Converted from C code from Solaris 8 (inet_pton)
*
* Any component of the string following a per-cent % is ignored.
*
* @param src a String representing an IPv6 address in textual format
* @return a byte array representing the IPv6 numeric address
*/
public static byte[] textToNumericFormatV6(String src)
{
// Shortest valid string is "::", hence at least 2 chars
if (src.length() < 2) {
return null;
}
int colonp;
char ch;
boolean saw_xdigit;
int val;
char[] srcb = src.toCharArray();
byte[] dst = new byte[INADDR16SZ];
int srcb_length = srcb.length;
int pc = src.indexOf ('%');
if (pc == srcb_length -1) {
return null;
}
if (pc != -1) {
srcb_length = pc;
}
colonp = -1;
int i = 0, j = 0;
/* Leading :: requires some special handling. */
if (srcb[i] == ':')
if (srcb[++i] != ':')
return null;
int curtok = i;
saw_xdigit = false;
val = 0;
while (i < srcb_length) {
ch = srcb[i++];
int chval = digit(ch, 16);
if (chval != -1) {
val <<= 4;
val |= chval;
if (val > 0xffff)
return null;
saw_xdigit = true;
continue;
}
if (ch == ':') {
curtok = i;
if (!saw_xdigit) {
if (colonp != -1)
return null;
colonp = j;
continue;
} else if (i == srcb_length) {
return null;
}
if (j + INT16SZ > INADDR16SZ)
return null;
dst[j++] = (byte) ((val >> 8) & 0xff);
dst[j++] = (byte) (val & 0xff);
saw_xdigit = false;
val = 0;
continue;
}
if (ch == '.' && ((j + INADDR4SZ) <= INADDR16SZ)) {
String ia4 = src.substring(curtok, srcb_length);
/* check this IPv4 address has 3 dots, i.e. A.B.C.D */
int dot_count = 0, index=0;
while ((index = ia4.indexOf ('.', index)) != -1) {
dot_count ++;
index ++;
}
if (dot_count != 3) {
return null;
}
byte[] v4addr = textToNumericFormatV4(ia4);
if (v4addr == null) {
return null;
}
for (int k = 0; k < INADDR4SZ; k++) {
dst[j++] = v4addr[k];
}
saw_xdigit = false;
break; /* '\0' was seen by inet_pton4(). */
}
return null;
}
if (saw_xdigit) {
if (j + INT16SZ > INADDR16SZ)
return null;
dst[j++] = (byte) ((val >> 8) & 0xff);
dst[j++] = (byte) (val & 0xff);
}
if (colonp != -1) {
int n = j - colonp;
if (j == INADDR16SZ)
return null;
for (i = 1; i <= n; i++) {
dst[INADDR16SZ - i] = dst[colonp + n - i];
dst[colonp + n - i] = 0;
}
j = INADDR16SZ;
}
if (j != INADDR16SZ)
return null;
byte[] newdst = convertFromIPv4MappedAddress(dst);
if (newdst != null) {
return newdst;
} else {
return dst;
}
}
/**
* @param src a String representing an IPv4 address in textual format
* @return a boolean indicating whether src is an IPv4 literal address
*/
public static boolean isIPv4LiteralAddress(String src) {
return textToNumericFormatV4(src) != null;
}
/**
* @param src a String representing an IPv6 address in textual format
* @return a boolean indicating whether src is an IPv6 literal address
*/
public static boolean isIPv6LiteralAddress(String src) {
return textToNumericFormatV6(src) != null;
}
/*
* Convert IPv4-Mapped address to IPv4 address. Both input and
* returned value are in network order binary form.
*
* @param src a String representing an IPv4-Mapped address in textual format
* @return a byte array representing the IPv4 numeric address
*/
public static byte[] convertFromIPv4MappedAddress(byte[] addr) {
if (isIPv4MappedAddress(addr)) {
byte[] newAddr = new byte[INADDR4SZ];
System.arraycopy(addr, 12, newAddr, 0, INADDR4SZ);
return newAddr;
}
return null;
}
/**
* Utility routine to check if the InetAddress is an
* IPv4 mapped IPv6 address.
*
* @return a boolean indicating if the InetAddress is
* an IPv4 mapped IPv6 address; or false if address is IPv4 address.
*/
private static boolean isIPv4MappedAddress(byte[] addr) {
if (addr.length < INADDR16SZ) {
return false;
}
if ((addr[0] == 0x00) && (addr[1] == 0x00) &&
(addr[2] == 0x00) && (addr[3] == 0x00) &&
(addr[4] == 0x00) && (addr[5] == 0x00) &&
(addr[6] == 0x00) && (addr[7] == 0x00) &&
(addr[8] == 0x00) && (addr[9] == 0x00) &&
(addr[10] == (byte)0xff) &&
(addr[11] == (byte)0xff)) {
return true;
}
return false;
}
/**
* Mapping from unscoped local Inet(6)Address to the same address
* including the correct scope-id, determined from NetworkInterface.
*/
private static final ConcurrentHashMap
cache = new ConcurrentHashMap<>();
/**
* Returns a scoped version of the supplied local, link-local ipv6 address
* if that scope-id can be determined from local NetworkInterfaces.
* If the address already has a scope-id or if the address is not local, ipv6
* or link local, then the original address is returned.
*
* @param address
* @exception SocketException if the given ipv6 link local address is found
* on more than one local interface
* @return
*/
public static InetAddress toScopedAddress(InetAddress address)
throws SocketException {
if (address instanceof Inet6Address && address.isLinkLocalAddress()
&& ((Inet6Address) address).getScopeId() == 0) {
InetAddress cached = null;
try {
cached = cache.computeIfAbsent(address, k -> findScopedAddress(k));
} catch (UncheckedIOException e) {
throw (SocketException)e.getCause();
}
return cached != null ? cached : address;
} else {
return address;
}
}
/**
* Same as above for InetSocketAddress
*/
public static InetSocketAddress toScopedAddress(InetSocketAddress address)
throws SocketException {
InetAddress addr;
InetAddress orig = address.getAddress();
if ((addr = toScopedAddress(orig)) == orig) {
return address;
} else {
return new InetSocketAddress(addr, address.getPort());
}
}
@SuppressWarnings("removal")
private static InetAddress findScopedAddress(InetAddress address) {
// PrivilegedExceptionAction> pa = () -> NetworkInterface.networkInterfaces()
// .flatMap(NetworkInterface::inetAddresses)
// .filter(a -> (a instanceof Inet6Address)
// && address.equals(a)
// && ((Inet6Address) a).getScopeId() != 0)
// .collect(Collectors.toList());
PrivilegedExceptionAction> pa = () -> {
List result = new ArrayList<>();
Enumeration enumeration = NetworkInterface.getNetworkInterfaces();
while(enumeration.hasMoreElements()) {
NetworkInterface ni = enumeration.nextElement();
Enumeration inetAddresses = ni.getInetAddresses();
while(inetAddresses.hasMoreElements()) {
InetAddress inetAddress = inetAddresses.nextElement();
if (inetAddress instanceof Inet6Address
&& address.equals(inetAddress)
&& ((Inet6Address) inetAddress).getScopeId() != 0) {
result.add(inetAddress);
}
}
}
return result;
};
List result;
try {
result = AccessController.doPrivileged(pa);
int sz = result.size();
if (sz == 0)
return null;
if (sz > 1)
throw new UncheckedIOException(new SocketException(
"Duplicate link local addresses: must specify scope-id"));
return result.get(0);
} catch (PrivilegedActionException pae) {
return null;
}
}
// See java.net.URI for more details on how to generate these
// masks.
//
// square brackets
private static final long L_IPV6_DELIMS = 0x0L; // "[]"
private static final long H_IPV6_DELIMS = 0x28000000L; // "[]"
// RFC 3986 gen-delims
private static final long L_GEN_DELIMS = 0x8400800800000000L; // ":/?#[]@"
private static final long H_GEN_DELIMS = 0x28000001L; // ":/?#[]@"
// These gen-delims can appear in authority
private static final long L_AUTH_DELIMS = 0x400000000000000L; // "@[]:"
private static final long H_AUTH_DELIMS = 0x28000001L; // "@[]:"
// colon is allowed in userinfo
private static final long L_COLON = 0x400000000000000L; // ":"
private static final long H_COLON = 0x0L; // ":"
// slash should be encoded in authority
private static final long L_SLASH = 0x800000000000L; // "/"
private static final long H_SLASH = 0x0L; // "/"
// backslash should always be encoded
private static final long L_BACKSLASH = 0x0L; // "\"
private static final long H_BACKSLASH = 0x10000000L; // "\"
// ASCII chars 0-31 + 127 - various controls + CRLF + TAB
private static final long L_NON_PRINTABLE = 0xffffffffL;
private static final long H_NON_PRINTABLE = 0x8000000000000000L;
// All of the above
private static final long L_EXCLUDE = 0x84008008ffffffffL;
private static final long H_EXCLUDE = 0x8000000038000001L;
private static final char[] OTHERS = {
8263,8264,8265,8448,8449,8453,8454,10868,
65109,65110,65119,65131,65283,65295,65306,65311,65312
};
// Tell whether the given character is found by the given mask pair
public static boolean match(char c, long lowMask, long highMask) {
if (c < 64)
return ((1L << c) & lowMask) != 0;
if (c < 128)
return ((1L << (c - 64)) & highMask) != 0;
return false; // other non ASCII characters are not filtered
}
// returns -1 if the string doesn't contain any characters
// from the mask, the index of the first such character found
// otherwise.
public static int scan(String s, long lowMask, long highMask) {
int i = -1, len;
if (s == null || (len = s.length()) == 0) return -1;
boolean match = false;
while (++i < len && !(match = match(s.charAt(i), lowMask, highMask)));
if (match) return i;
return -1;
}
public static int scan(String s, long lowMask, long highMask, char[] others) {
int i = -1, len;
if (s == null || (len = s.length()) == 0) return -1;
boolean match = false;
char c, c0 = others[0];
while (++i < len && !(match = match((c=s.charAt(i)), lowMask, highMask))) {
if (c >= c0 && (Arrays.binarySearch(others, c) > -1)) {
match = true; break;
}
}
if (match) return i;
return -1;
}
private static String describeChar(char c) {
if (c < 32 || c == 127) {
if (c == '\n') return "LF";
if (c == '\r') return "CR";
return "control char (code=" + (int)c + ")";
}
if (c == '\\') return "'\\'";
return "'" + c + "'";
}
private static String checkUserInfo(String str) {
// colon is permitted in user info
int index = scan(str, L_EXCLUDE & ~L_COLON,
H_EXCLUDE & ~H_COLON);
if (index >= 0) {
return "Illegal character found in user-info: "
+ describeChar(str.charAt(index));
}
return null;
}
private static String checkHost(String str) {
int index;
if (str.startsWith("[") && str.endsWith("]")) {
str = str.substring(1, str.length() - 1);
if (isIPv6LiteralAddress(str)) {
index = str.indexOf('%');
if (index >= 0) {
index = scan(str = str.substring(index),
L_NON_PRINTABLE | L_IPV6_DELIMS,
H_NON_PRINTABLE | H_IPV6_DELIMS);
if (index >= 0) {
return "Illegal character found in IPv6 scoped address: "
+ describeChar(str.charAt(index));
}
}
return null;
}
return "Unrecognized IPv6 address format";
} else {
index = scan(str, L_EXCLUDE, H_EXCLUDE);
if (index >= 0) {
return "Illegal character found in host: "
+ describeChar(str.charAt(index));
}
}
return null;
}
private static String checkAuth(String str) {
int index = scan(str,
L_EXCLUDE & ~L_AUTH_DELIMS,
H_EXCLUDE & ~H_AUTH_DELIMS);
if (index >= 0) {
return "Illegal character found in authority: "
+ describeChar(str.charAt(index));
}
return null;
}
// check authority of hierarchical URL. Appropriate for
// HTTP-like protocol handlers
public static String checkAuthority(URL url) {
String s, u, h;
if (url == null) return null;
if ((s = checkUserInfo(u = url.getUserInfo())) != null) {
return s;
}
if ((s = checkHost(h = url.getHost())) != null) {
return s;
}
if (h == null && u == null) {
return checkAuth(url.getAuthority());
}
return null;
}
// minimal syntax checks - deeper check may be performed
// by the appropriate protocol handler
public static String checkExternalForm(URL url) {
String s;
if (url == null) return null;
int index = scan(s = url.getUserInfo(),
L_NON_PRINTABLE | L_SLASH,
H_NON_PRINTABLE | H_SLASH);
if (index >= 0) {
return "Illegal character found in authority: "
+ describeChar(s.charAt(index));
}
if ((s = checkHostString(url.getHost())) != null) {
return s;
}
return null;
}
public static String checkHostString(String host) {
if (host == null) return null;
int index = scan(host,
L_NON_PRINTABLE | L_SLASH,
H_NON_PRINTABLE | H_SLASH,
OTHERS);
if (index >= 0) {
return "Illegal character found in host: "
+ describeChar(host.charAt(index));
}
return null;
}
/**
* Returns the numeric value of the character {@code ch} in the
* specified radix.
*
* @param ch the character to be converted.
* @param radix the radix.
* @return the numeric value represented by the character in the
* specified radix.
*/
public static int digit(char ch, int radix) {
if (ALLOW_AMBIGUOUS_IPADDRESS_LITERALS_SP_VALUE) {
return Character.digit(ch, radix);
} else {
return parseAsciiDigit(ch, radix);
}
}
/**
* Try to parse String as IPv4 address literal by following
* BSD-style formatting rules.
*
* @param input input string
* @return {@code true} if input string is parsable as IPv4 address literal,
* {@code false} otherwise.
*/
public static boolean isBsdParsableV4(String input) {
char firstSymbol = input.charAt(0);
// Check if first digit is not a decimal digit
if (parseAsciiDigit(firstSymbol, DECIMAL) == -1) {
return false;
}
// Last character is dot OR is not a supported digit: [0-9,A-F,a-f]
char lastSymbol = input.charAt(input.length() - 1);
if (lastSymbol == '.' || parseAsciiHexDigit(lastSymbol) == -1) {
return false;
}
// Parse IP address fields
CharBuffer charBuffer = CharBuffer.wrap(input);
int fieldNumber = 0;
while (charBuffer.hasRemaining()) {
long fieldValue = -1L;
// Try to parse fields in all supported radixes
for (int radix : SUPPORTED_RADIXES) {
fieldValue = parseV4FieldBsd(radix, charBuffer, fieldNumber);
if (fieldValue >= 0) {
fieldNumber++;
break;
} else if (fieldValue == TERMINAL_PARSE_ERROR) {
return false;
}
}
// If field can't be parsed as one of supported radixes stop
// parsing
if (fieldValue < 0) {
return false;
}
}
return true;
}
/**
* Method tries to parse IP address field that starts from {@linkplain CharBuffer#position()
* current position} of the provided character buffer.
*
* This method supports three {@code "radix"} values to decode field values in
* {@code "HEXADECIMAL (radix=16)"}, {@code "DECIMAL (radix=10)"} and
* {@code "OCTAL (radix=8)"} radixes.
*
* If {@code -1} value is returned the char buffer position is reset to the value
* it was before it was called.
*
* Method returns {@code -2} if formatting illegal for all supported {@code radix}
* values is observed, and there is no point in checking other radix values.
* That includes the following cases:
* - Two subsequent dots are observer
*
- Number of dots more than 3
*
- Field value exceeds max allowed
*
- Character is not a valid digit for the requested {@code radix} value, given
* that a field has the radix specific prefix
*
*
* @param radix digits encoding radix to use for parsing. Valid values: 8, 10, 16.
* @param buffer {@code CharBuffer} with position set to the field's fist character
* @param fieldNumber parsed field number
* @return {@code CANT_PARSE_IN_RADIX} if field can not be parsed in requested {@code radix}.
* {@code TERMINAL_PARSE_ERROR} if field can't be parsed and the whole parse process should be terminated.
* Parsed field value otherwise.
*/
private static long parseV4FieldBsd(int radix, CharBuffer buffer, int fieldNumber) {
int initialPos = buffer.position();
long val = 0;
int digitsCount = 0;
if (!checkPrefix(buffer, radix)) {
val = CANT_PARSE_IN_RADIX;
}
boolean dotSeen = false;
while (buffer.hasRemaining() && val != CANT_PARSE_IN_RADIX && !dotSeen) {
char c = buffer.get();
if (c == '.') {
dotSeen = true;
// Fail if 4 dots in IP address string.
// fieldNumber counter starts from 0, therefore 3
if (fieldNumber == 3) {
// Terminal state, can stop parsing: too many fields
return TERMINAL_PARSE_ERROR;
}
// Check for literals with two dots, like '1.2..3', '1.2.3..'
if (digitsCount == 0) {
// Terminal state, can stop parsing: dot with no digits
return TERMINAL_PARSE_ERROR;
}
if (val > 255) {
// Terminal state, can stop parsing: too big value for an octet
return TERMINAL_PARSE_ERROR;
}
} else {
int dv = parseAsciiDigit(c, radix);
if (dv >= 0) {
digitsCount++;
val *= radix;
val += dv;
} else {
// Spotted digit can't be parsed in the requested 'radix'.
// The order in which radixes are checked - hex, octal, decimal:
// - if symbol is not a valid digit in hex radix - terminal
// - if symbol is not a valid digit in octal radix, and given
// that octal prefix was observed before - terminal
// - if symbol is not a valid digit in decimal radix - terminal
return TERMINAL_PARSE_ERROR;
}
}
}
if (val == CANT_PARSE_IN_RADIX) {
buffer.position(initialPos);
} else if (!dotSeen) {
// It is the last field - check its value
// This check will ensure that address strings with less
// than 4 fields, i.e. A, A.B and A.B.C address types
// contain value less then the allowed maximum for the last field.
long maxValue = (1L << ((4 - fieldNumber) * 8)) - 1;
if (val > maxValue) {
// Terminal state, can stop parsing: last field value exceeds its
// allowed value
return TERMINAL_PARSE_ERROR;
}
}
return val;
}
// This method moves the position of the supplied CharBuffer by analysing the digit prefix
// symbols if any.
// The caller should reset the position when method returns false.
private static boolean checkPrefix(CharBuffer buffer, int radix) {
switch (radix) {
case OCTAL:
return isOctalFieldStart(buffer);
case DECIMAL:
return isDecimalFieldStart(buffer);
case HEXADECIMAL:
return isHexFieldStart(buffer);
default:
throw new AssertionError("Not supported radix");
}
}
// This method always moves the position of the supplied CharBuffer
// removing the octal prefix symbols '0'.
// The caller should reset the position when method returns false.
private static boolean isOctalFieldStart(CharBuffer cb) {
// .0 is not treated as octal field
if (cb.remaining() < 2) {
return false;
}
// Fetch two first characters
int position = cb.position();
char first = cb.get();
char second = cb.get();
// Return false if the first char is not octal prefix '0' or second is a
// field separator - parseV4FieldBsd will reset position to start of the field.
// '.0.' fields will be successfully parsed in decimal radix.
boolean isOctalPrefix = first == '0' && second != '.';
// If the prefix looks like octal - consume '0', otherwise 'false' is returned
// and caller will reset the buffer position.
if (isOctalPrefix) {
cb.position(position + 1);
}
return isOctalPrefix;
}
// This method doesn't move the position of the supplied CharBuffer
private static boolean isDecimalFieldStart(CharBuffer cb) {
return cb.hasRemaining();
}
// This method always moves the position of the supplied CharBuffer
// removing the hexadecimal prefix symbols '0x'.
// The caller should reset the position when method returns false.
private static boolean isHexFieldStart(CharBuffer cb) {
if (cb.remaining() < 2) {
return false;
}
char first = cb.get();
char second = cb.get();
return first == '0' && (second == 'x' || second == 'X');
}
// Parse ASCII digit in given radix
private static int parseAsciiDigit(char c, int radix) {
assert radix == OCTAL || radix == DECIMAL || radix == HEXADECIMAL;
if (radix == HEXADECIMAL) {
return parseAsciiHexDigit(c);
}
int val = c - '0';
return (val < 0 || val >= radix) ? -1 : val;
}
// Parse ASCII digit in hexadecimal radix
private static int parseAsciiHexDigit(char digit) {
char c = Character.toLowerCase(digit);
if (c >= 'a' && c <= 'f') {
return c - 'a' + 10;
}
return parseAsciiDigit(c, DECIMAL);
}
// Supported radixes
private static final int HEXADECIMAL = 16;
private static final int DECIMAL = 10;
private static final int OCTAL = 8;
// Order in which field formats are exercised to parse one IP address textual field
private static final int[] SUPPORTED_RADIXES = new int[]{HEXADECIMAL, OCTAL, DECIMAL};
// BSD parser's return values
private final static long CANT_PARSE_IN_RADIX = -1L;
private final static long TERMINAL_PARSE_ERROR = -2L;
private static final String ALLOW_AMBIGUOUS_IPADDRESS_LITERALS_SP = "jdk.net.allowAmbiguousIPAddressLiterals";
private static final boolean ALLOW_AMBIGUOUS_IPADDRESS_LITERALS_SP_VALUE = Boolean.valueOf(
GetPropertyAction.privilegedGetProperty(ALLOW_AMBIGUOUS_IPADDRESS_LITERALS_SP, "false"));
}