001 package org.apache.commons.net.ntp; 002 /* 003 * Licensed to the Apache Software Foundation (ASF) under one or more 004 * contributor license agreements. See the NOTICE file distributed with 005 * this work for additional information regarding copyright ownership. 006 * The ASF licenses this file to You under the Apache License, Version 2.0 007 * (the "License"); you may not use this file except in compliance with 008 * the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 019 020 /*** 021 * Common NtpUtils Helper class. 022 * 023 * @author Jason Mathews, MITRE Corp 024 * 025 * @version $Revision: 929344 $ $Date: 2010-03-31 01:20:49 +0100 (Wed, 31 Mar 2010) $ 026 */ 027 public final class NtpUtils { 028 029 /*** 030 * Returns 32-bit integer address to IPv4 address string "%d.%d.%d.%d" format. 031 * 032 * @param address the 32-bit address 033 * @return the raw IP address in a string format. 034 */ 035 public static String getHostAddress(int address) 036 { 037 return ((address >>> 24) & 0xFF) + "." + 038 ((address >>> 16) & 0xFF) + "." + 039 ((address >>> 8) & 0xFF) + "." + 040 ((address >>> 0) & 0xFF); 041 } 042 043 /*** 044 * Returns NTP packet reference identifier as IP address. 045 * 046 * @param packet NTP packet 047 * @return the packet reference id (as IP address) in "%d.%d.%d.%d" format. 048 */ 049 public static String getRefAddress(NtpV3Packet packet) 050 { 051 int address = (packet == null) ? 0 : packet.getReferenceId(); 052 return getHostAddress(address); 053 } 054 055 /*** 056 * Get refId as reference clock string (e.g. GPS, WWV, LCL). If string is 057 * invalid (non-ASCII character) then returns empty string "". 058 * For details refer to the <A HREF="http://www.eecis.udel.edu/~mills/ntp/html/refclock.html#list">Comprehensive 059 * List of Clock Drivers</A>. 060 * 061 * @param message 062 * @return reference clock string if primary NTP server 063 */ 064 public static String getReferenceClock(NtpV3Packet message) { 065 if (message == null) 066 return ""; 067 int refId = message.getReferenceId(); 068 if (refId == 0) 069 return ""; 070 StringBuilder buf = new StringBuilder(4); 071 // start at highest-order byte (0x4c434c00 -> LCL) 072 for (int shiftBits = 24; shiftBits >= 0; shiftBits -= 8) 073 { 074 char c = (char) ((refId >>> shiftBits) & 0xff); 075 if (c == 0) break; // 0-terminated ASCII string 076 if (!Character.isLetterOrDigit(c)) 077 return ""; 078 buf.append(c); 079 } 080 return buf.toString(); 081 } 082 083 /*** 084 * Return human-readable name of message mode type (RFC 1305). 085 * 086 * @param mode 087 * @return mode name 088 */ 089 public static String getModeName(int mode) 090 { 091 switch (mode) { 092 case NtpV3Packet.MODE_RESERVED: 093 return "Reserved"; 094 case NtpV3Packet.MODE_SYMMETRIC_ACTIVE: 095 return "Symmetric Active"; 096 case NtpV3Packet.MODE_SYMMETRIC_PASSIVE: 097 return "Symmetric Passive"; 098 case NtpV3Packet.MODE_CLIENT: 099 return "Client"; 100 case NtpV3Packet.MODE_SERVER: 101 return "Server"; 102 case NtpV3Packet.MODE_BROADCAST: 103 return "Broadcast"; 104 case NtpV3Packet.MODE_CONTROL_MESSAGE: 105 return "Control"; 106 case NtpV3Packet.MODE_PRIVATE: 107 return "Private"; 108 default: 109 return "Unknown"; 110 } 111 } 112 113 }