Method getTeredoInfo

output/java_guava/1.4.19/InetAddresses.java:686–701

Returns the Teredo information embedded in a Teredo address. @param ip Inet6Address to be examined for embedded Teredo information @return extracted TeredoInfo @throws IllegalArgumentException if the argument is not a valid IPv6 Teredo address

(Inet6Address ip)

  public static TeredoInfo getTeredoInfo(Inet6Address ip) {
    Preconditions.checkArgument(isTeredoAddress(ip), "Address '%s' is not a Teredo address.", toAddrString(ip));
    byte[] bytes = ip.getAddress();
    Inet4Address server = getInet4Address(Arrays.copyOfRange(bytes, 4, 8));
    int flags = ByteStreams.newDataInput(bytes, 8).readShort() & 0xffff;

    // Teredo obfuscates the mapped client port, per section 4 of the RFC.
    int port = ~ByteStreams.newDataInput(bytes, 10).readShort() & 0xffff;
    byte[] clientBytes = Arrays.copyOfRange(bytes, 12, 16);
    for (int i = 0; i < clientBytes.length; i++) {
      // Teredo obfuscates the mapped client IP, per section 4 of the RFC.
      clientBytes[i] = (byte) ~ clientBytes[i];
    }
    Inet4Address client = getInet4Address(clientBytes);
    return new TeredoInfo(server, client, port, flags);
  }

  /**
   * Evaluates whether the argument is an ISATAP address.