1 package org.apache.commons.net.ntp; 2 /* 3 * Licensed to the Apache Software Foundation (ASF) under one or more 4 * contributor license agreements. See the NOTICE file distributed with 5 * this work for additional information regarding copyright ownership. 6 * The ASF licenses this file to You under the Apache License, Version 2.0 7 * (the "License"); you may not use this file except in compliance with 8 * the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 20 /*** 21 * Common NtpUtils Helper class. 22 * 23 * @author Jason Mathews, MITRE Corp 24 * 25 * @version $Revision: 489397 $ $Date: 2006-12-21 16:28:51 +0000 (Thu, 21 Dec 2006) $ 26 */ 27 public final class NtpUtils { 28 29 /*** 30 * Returns 32-bit integer address to IPv4 address string "%d.%d.%d.%d" format. 31 * 32 * @param address the 32-bit address 33 * @return the raw IP address in a string format. 34 */ 35 public static String getHostAddress(int address) 36 { 37 return ((address >>> 24) & 0xFF) + "." + 38 ((address >>> 16) & 0xFF) + "." + 39 ((address >>> 8) & 0xFF) + "." + 40 ((address >>> 0) & 0xFF); 41 } 42 43 /*** 44 * Returns NTP packet reference identifier as IP address. 45 * 46 * @param packet NTP packet 47 * @return the packet reference id (as IP address) in "%d.%d.%d.%d" format. 48 */ 49 public static String getRefAddress(NtpV3Packet packet) 50 { 51 int address = (packet == null) ? 0 : packet.getReferenceId(); 52 return getHostAddress(address); 53 } 54 55 /*** 56 * Get refId as reference clock string (e.g. GPS, WWV, LCL). If string is 57 * invalid (non-ASCII character) then returns empty string "". 58 * For details refer to the <A HREF="http://www.eecis.udel.edu/~mills/ntp/html/refclock.html#list">Comprehensive 59 * List of Clock Drivers</A>. 60 * 61 * @param message 62 * @return reference clock string if primary NTP server 63 */ 64 public static String getReferenceClock(NtpV3Packet message) { 65 if (message == null) 66 return ""; 67 int refId = message.getReferenceId(); 68 if (refId == 0) 69 return ""; 70 StringBuffer buf = new StringBuffer(4); 71 // start at highest-order byte (0x4c434c00 -> LCL) 72 for (int shiftBits = 24; shiftBits >= 0; shiftBits -= 8) 73 { 74 char c = (char) ((refId >>> shiftBits) & 0xff); 75 if (c == 0) break; // 0-terminated ASCII string 76 if (!Character.isLetterOrDigit(c)) 77 return ""; 78 buf.append(c); 79 } 80 return buf.toString(); 81 } 82 83 /*** 84 * Return human-readable name of message mode type (RFC 1305). 85 * 86 * @param mode 87 * @return mode name 88 */ 89 public static String getModeName(int mode) 90 { 91 switch (mode) { 92 case NtpV3Packet.MODE_RESERVED: 93 return "Reserved"; 94 case NtpV3Packet.MODE_SYMMETRIC_ACTIVE: 95 return "Symmetric Active"; 96 case NtpV3Packet.MODE_SYMMETRIC_PASSIVE: 97 return "Symmetric Passive"; 98 case NtpV3Packet.MODE_CLIENT: 99 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 }