result = NetworkInterface.networkInterfaces()
.flatMap(NetworkInterface::inetAddresses)
.filter(a -> (a instanceof Inet6Address)
&& address.equals(a)
&& ((Inet6Address) a).getScopeId() != 0)
.toList();
var 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 (SocketException socketException) {
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;
// excluded delims: "<>\" " - we don't include % and # here
private static final long L_EXCLUDED_DELIMS = 0x5000000500000000L;
private static final long H_EXCLUDED_DELIMS = 0x0L;
// unwise "{}|\\^[]`";
private static final long L_UNWISE = 0x0L;
private static final long H_UNWISE = 0x3800000178000000L;
private static final long L_FRAGMENT = 0x0000000800000000L;
private static final long H_FRAGMENT = 0x0L;
private static final long L_QUERY = 0x8000000000000000L;
private static final long H_QUERY = 0x0L;
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 + "'";
}
// Check user-info component.
// This method returns an error message if a problem
// is found. The caller is expected to use that message to
// throw an exception.
public static String checkUserInfo(String str) {
// colon is permitted in user info
int index = scan(str, MASKS.L_USERINFO_MASK,
MASKS.H_USERINFO_MASK);
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),
MASKS.L_SCOPE_MASK, MASKS.H_SCOPE_MASK);
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 | MASKS.L_HOSTNAME_MASK,
H_EXCLUDE | MASKS.H_HOSTNAME_MASK, OTHERS);
if (index >= 0) {
return "Illegal character found in host: "
+ describeChar(str.charAt(index));
}
}
return null;
}
// Simple checks for the authority component.
// Deeper checks on the various parts of a server-based
// authority component may be performed by calling
// #checkAuthority(URL url)
// This method returns an error message if a problem
// is found. The caller is expected to use that message to
// throw an exception.
public 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 (server based) URL.
// Appropriate for HTTP-like protocol handlers
// This method returns an error message if a problem
// is found. The caller is expected to use that message to
// throw an exception.
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 if delayed parsing is
// enabled - deeper check will be performed
// later by the appropriate protocol handler
// This method returns an error message if a problem
// is found. The caller is expected to use that message to
// throw an exception.
public static String checkExternalForm(URL url) {
String s;
if (url == null) return null;
boolean earlyURLParsing = earlyURLParsing();
String userInfo = url.getUserInfo();
if (earlyURLParsing) {
if ((s = checkUserInfo(userInfo)) != null) return s;
} else {
int index = scan(s = userInfo,
L_NON_PRINTABLE | L_SLASH,
H_NON_PRINTABLE | H_SLASH);
if (index >= 0) {
return "Illegal character found in authority: "
+ describeChar(s.charAt(index));
}
}
String host = url.getHost();
if ((s = checkHostString(host)) != null) {
return s;
}
return null;
}
// Check host component.
// This method returns an error message if a problem
// is found. The caller is expected to use that message to
// throw an exception.
public static String checkHostString(String host) {
if (host == null) return null;
if (earlyURLParsing()) {
// also validate IPv6 literal format if present
return checkHost(host);
} else {
int index = scan(host,
MASKS.L_HOSTNAME_MASK,
MASKS.H_HOSTNAME_MASK,
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) {
return parseBsdLiteralV4(input) != null;
}
/**
* Parse String as IPv4 address literal by following
* POSIX-style formatting rules.
*
* @param input a String representing an IPv4 address in POSIX format
* @return a byte array representing the IPv4 numeric address
* if input string is a parsable POSIX formatted IPv4 address literal,
* {@code null} otherwise.
*/
public static byte[] parseBsdLiteralV4(String input) {
byte[] res = new byte[]{0,0,0,0};
int len = input.length();
if (len == 0) {
return null;
}
char firstSymbol = input.charAt(0);
// Check if first digit is not a decimal digit
if (parseAsciiDigit(firstSymbol, DECIMAL) == -1) {
return null;
}
// Last character is dot OR is not a supported digit: [0-9,A-F,a-f]
char lastSymbol = input.charAt(len - 1);
if (lastSymbol == '.' || parseAsciiHexDigit(lastSymbol) == -1) {
return null;
}
// Parse IP address fields
CharBuffer charBuffer = CharBuffer.wrap(input);
int fieldNumber = 0;
long fieldValue = -1L;
while (charBuffer.hasRemaining()) {
fieldValue = -1L;
// Try to parse fields in all supported radixes
for (int radix : SUPPORTED_RADIXES) {
fieldValue = parseV4FieldBsd(radix, charBuffer, fieldNumber);
if (fieldValue >= 0) {
if (fieldValue < 256) {
// Store the parsed field in the byte buffer.
// If the field value is greater than 255, it can only be the last field.
// If it is not the last one, parseV4FieldBsd enforces this limit
// and returns TERMINAL_PARSE_ERROR.
res[fieldNumber] = (byte) fieldValue;
}
fieldNumber++;
break;
} else if (fieldValue == TERMINAL_PARSE_ERROR) {
return null;
}
}
// If field can't be parsed as one of supported radixes stop
// parsing
if (fieldValue < 0) {
return null;
}
}
// The last field value must be non-negative
if (fieldValue < 0) {
return null;
}
// If the last fieldValue is greater than 255 (fieldNumber < 4),
// it is written to the last (4 - (fieldNumber - 1)) octets
// in the network order
if (fieldNumber < 4) {
for (int i = 3; i >= fieldNumber - 1; --i) {
res[i] = (byte) (fieldValue & 255);
fieldValue >>= 8;
}
}
return res;
}
/**
* 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) {
return switch (radix) {
case OCTAL -> isOctalFieldStart(buffer);
case DECIMAL -> isDecimalFieldStart(buffer);
case HEXADECIMAL -> 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
public 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);
}
public static boolean earlyURLParsing() {
return !MASKS.DELAY_URL_PARSING_SP_VALUE;
}
public static boolean delayURLParsing() {
return MASKS.DELAY_URL_PARSING_SP_VALUE;
}
// 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 static final long CANT_PARSE_IN_RADIX = -1L;
private static final 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.getBoolean(ALLOW_AMBIGUOUS_IPADDRESS_LITERALS_SP);
private static class MASKS {
private static final String DELAY_URL_PARSING_SP = "jdk.net.url.delayParsing";
private static final boolean DELAY_URL_PARSING_SP_VALUE;
static final long L_USERINFO_MASK = L_EXCLUDE & ~L_COLON;
static final long H_USERINFO_MASK = H_EXCLUDE & ~H_COLON;
static final long L_HOSTNAME_MASK;
static final long H_HOSTNAME_MASK;
static final long L_SCOPE_MASK;
static final long H_SCOPE_MASK;
static {
var value = System.getProperty(DELAY_URL_PARSING_SP, "false");
DELAY_URL_PARSING_SP_VALUE = value.isEmpty()
|| Boolean.parseBoolean(value);
if (DELAY_URL_PARSING_SP_VALUE) {
L_HOSTNAME_MASK = L_NON_PRINTABLE | L_SLASH;
H_HOSTNAME_MASK = H_NON_PRINTABLE | H_SLASH;
L_SCOPE_MASK = L_NON_PRINTABLE | L_IPV6_DELIMS;
H_SCOPE_MASK = H_NON_PRINTABLE | H_IPV6_DELIMS;
} else {
// the hostname mask can also forbid [ ] brackets, because IPv6 should be
// checked early before the mask is used when earlier parsing checks are performed
L_HOSTNAME_MASK = L_NON_PRINTABLE | L_SLASH | L_UNWISE | L_EXCLUDED_DELIMS;
H_HOSTNAME_MASK = H_NON_PRINTABLE | H_SLASH | H_UNWISE | H_EXCLUDED_DELIMS;
L_SCOPE_MASK = L_NON_PRINTABLE | L_IPV6_DELIMS | L_SLASH | L_BACKSLASH | L_FRAGMENT | L_QUERY;
H_SCOPE_MASK = H_NON_PRINTABLE | H_IPV6_DELIMS | H_SLASH | H_BACKSLASH | H_FRAGMENT | H_QUERY;
}
}
}
}