Imported from /home/lorry/working-area/delta_ntp/ntp-4.2.8p2.tar.gz.HEADntp-4.2.8p2master

6 files changed, 168 insertions, 27 deletions

diff --git a/html/build.html b/html/build.html
index 9683b29..5e3c2d8 100644
--- a/html/build.html
+++ b/html/build.html
@@ -11,7 +11,7 @@
 <img src="pic/beaver.gif" alt="gif" align="left"><a href="http://www.eecis.udel.edu/%7emills/pictures.html">from <i>Pogo</i>, Walt Kelly</a>
 <p>For putting out compiler fires.</p>
 <p>Last update:
-  <!-- #BeginDate format:En2m -->31-Mar-2014  05:39<!-- #EndDate -->
+  <!-- #BeginDate format:En2m -->1-Apr-2015  02:57<!-- #EndDate -->
 </p>
 <br clear="left">
 <h4>Related Links</h4>
@@ -27,7 +27,7 @@
 </ul>
 <hr>
 <h4 id="build">Building and Installing the Distribution</h4>
-<p>It is not possible in a software distribution such as this to support every individual computer and operating system with a common executable, even with the same system but different versions and options. Therefore, it is necessary to configure, build and install for each system and version. In almost all cases, these procedures are completely automatic, The user types <tt>./configure</tt>, <tt>make</tt> and <tt>install</tt> in that order and the autoconfigure system does the rest. There are some exceptions, as noted below and on the <a href="hints.html">Hints and Kinks</a> pages.</p>
+<p>It is not possible in a software distribution such as this to support every individual computer and operating system with a common executable, even with the same system but different versions and options. Therefore, it is necessary to configure, build and install for each system and version. In almost all cases, these procedures are completely automatic, The user types <tt>./configure</tt>, and <tt>make install</tt> in that order and the autoconfigure system does the rest. There are some exceptions, as noted below and on the <a href="hints.html">Hints and Kinks</a> pages.</p>
 <p>If available, the OpenSSL library from <a href="http://www.openssl.org">http://www.openssl.org</a> is used to support public key cryptography. The library must be built and installed prior to building NTP. The procedures for doing that are included in the OpenSSL documentation. The library is found during the normal NTP configure phase and the interface routines compiled automatically. Only the <tt>libcrypto.a</tt> library file and <tt>openssl</tt> header files are needed. If the library is not available or disabled, this step is not required.</p>
 <p>The <a href="config.html">Build Options</a> page describes a number of options that determine whether debug support is included, whether and which reference clock drivers are included and the locations of the executables and library files, if not the default. By default debugging options and all reference clock drivers are included.</p>
 <h4 id="unix">Building and Installing for Unix</h4>
diff --git a/html/confopt.html b/html/confopt.html
index 8c8ae37..b964d24 100644
--- a/html/confopt.html
+++ b/html/confopt.html
@@ -91,11 +91,13 @@ outgoing NTP packets. Versions 1-4 are the choices, with version 4 the default.<
 <h4 id="aux">Auxiliary Commands</h4>
 <dl>
 	<dt id="broadcastclient"><tt>broadcastclient</tt></dt>
-	<dd>Enable reception of broadcast server messages to any local interface (type	b address). Ordinarily, upon receiving a broadcast message for the first time, the broadcast client measures the nominal server propagation delay using a brief client/server exchange, after which it continues in listen-only mode. If a nonzero value is specified in the <tt>broadcastdelay</tt> command, the value becomes the delay and the volley is not executed. Note: the <tt>novolley</tt> option has been deprecated for future enhancements. Note that, in order to avoid accidental or malicious disruption in this mode, both the server and client should operate using symmetric key or public key authentication as described in the <a href="authopt.html">Authentication Options</a> page. Note that the volley is required with public key authentication in order to run the Autokey protocol..</dd>
+	<dd>Enable reception of broadcast server messages to any local interface (type	b address). Ordinarily, upon receiving a broadcast message for the first time, the broadcast client measures the nominal server propagation delay using a brief client/server exchange, after which it continues in listen-only mode. If a nonzero value is specified in the <tt>broadcastdelay</tt> command, the value becomes the delay and the volley is not executed. Note: the <tt>novolley</tt> option has been deprecated for future enhancements. Note that, in order to avoid accidental or malicious disruption in this mode, both the server and client should operate using symmetric key or public key authentication as described in the <a href="authopt.html">Authentication Options</a> page. Note that the volley is required with public key authentication in order to run the Autokey protocol.</dd>
   <dt id="manycastserver"><tt>manycastserver <i>address</i> [...]</tt></dt>
 	<dd>Enable reception of manycast client messages (type m) to the multicasts group address(es) (type m) specified. At least one address is required. Note that, in order to avoid accidental or malicious disruption, both the server and client should operate using symmetric key or public key authentication as described in the <a href="authopt.html">Authentication Options</a> page.</dd>
 	<dt id="multicastclient"><tt>multicastclient <i>address</i> [...]</tt></dt>
 	<dd>Enable reception of multicast server messages to the multicast group address(es) (type m) specified. Upon receiving a message for the first time, the multicast client measures the nominal server propagation delay using a brief client/server exchange with the server, then enters the broadcast client mode, in which it synchronizes to succeeding multicast messages. Note that, in order to avoid accidental or malicious disruption in this mode, both the server and client should operate using symmetric key or public key authentication as described in the <a href="authopt.html">Authentication Options</a> page.</dd>
+	<dt id="mdnstries"><tt>mdnstries</tt> <i>number</i></dt>
+	<dd>If we are participating in mDNS, after we have synched for the first time we attempt to register with the mDNS system.  If that registration attempt fails, we try again at one minute intervals for up to <tt>mdnstries</tt> times.  After all, <tt>ntpd</tt> may be starting before mDNS.  The default value for <tt>mdnstries</tt> is 5.</dd>
 </dl>
 <hr>
 <script type="text/javascript" language="javascript" src="scripts/footer.txt"></script>
diff --git a/html/copyright.html b/html/copyright.html
index 08272d4..94fffc4 100644
--- a/html/copyright.html
+++ b/html/copyright.html
@@ -10,16 +10,16 @@
 <h3>Copyright Notice</h3>
 <img src="pic/sheepb.jpg" alt="jpg" align="left"> "Clone me," says Dolly sheepishly.
 <p>Last update:
-  <!-- #BeginDate format:En2m -->9-Aug-2014  07:56<!-- #EndDate -->
+  <!-- #BeginDate format:En2m -->17-Jan-2015  00:16<!-- #EndDate -->
     UTC</p>
 <br clear="left">
 </p>
 <hr>
-<p>The following copyright notice applies to all files collectively  called the Network Time Protocol Version 4 Distribution. Unless  specifically declared otherwise in an individual file, this notice  applies as if the text was explicitly included in the file.</p>
+<p>The following copyright notice applies to all files collectively  called the Network Time Protocol Version 4 Distribution. Unless  specifically declared otherwise in an individual file, this entire notice  applies as if the text was explicitly included in the file.</p>
 <pre>
 ***********************************************************************
 *                                                                     *
-* Copyright (c) University of Delaware 1992-2014                      *
+* Copyright (c) University of Delaware 1992-2015                      *
 *                                                                     *
 * Permission to use, copy, modify, and distribute this software and   *
 * its documentation for any purpose with or without fee is hereby     *
@@ -35,6 +35,38 @@
 *                                                                     *
 ***********************************************************************
 </pre>
+<p>Content starting in 2011 from Harlan Stenn, Danny Mayer, and Martin Burnicki is:</p>
+<pre>
+***********************************************************************
+*                                                                     *
+* Copyright (c) Network Time Foundation 2011-2015                     *
+*                                                                     *
+* All Rights Reserved                                                 *
+*                                                                     *
+* Redistribution and use in source and binary forms, with or without  *
+* modification, are permitted provided that the following conditions  *
+* are met:                                                            *
+* 1. Redistributions of source code must retain the above copyright   *
+*    notice, this list of conditions and the following disclaimer.    *
+* 2. Redistributions in binary form must reproduce the above          *
+*    copyright notice, this list of conditions and the following      *
+*    disclaimer in the documentation and/or other materials provided  *
+*    with the distribution.                                           *
+*                                                                     *
+* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS  *
+* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED   *
+* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE  *
+* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE    *
+* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR *
+* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT   *
+* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR  *
+* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF          *
+* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT           *
+* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE   *
+* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH    *
+* DAMAGE.                                                             *
+***********************************************************************
+</pre>
 <p>The following individuals contributed in part to the Network Time  Protocol Distribution Version 4 and are acknowledged as authors of this  work.</p>
 <ol>
   <li><a href="mailto:%20takao_abe@xurb.jp">Takao Abe &lt;takao_abe@xurb.jp&gt;</a> Clock driver for JJY receivers</li>
diff --git a/html/drivers/driver28.html b/html/drivers/driver28.html
index 8c7fd80..efa862f 100644
--- a/html/drivers/driver28.html
+++ b/html/drivers/driver28.html
@@ -7,6 +7,10 @@
         <meta name="GENERATOR" content="Mozilla/4.01 [en] (Win95; I) [Netscape]">
         <title>Shared Memory Driver</title>
         <link href="scripts/style.css" type="text/css" rel="stylesheet">
+	<style type="text/css">
+	  table.dlstable { font-size:85%; }
+	  td.ttf{ font-family:Courier; font-weight:bold; }
+	</style>
     </head>
 
     <body>
@@ -21,7 +25,13 @@
             Driver ID: <tt>SHM</tt></p>
 
         <h4>Description</h4>
-        <p>This driver receives its reference clock info from a shared memory-segment. The shared memory-segment is created with owner-only access for unit 0 and 1, and world access for unit 2 and 3</p>
+        <p>This driver receives its reference clock info from a shared
+        memory-segment. The shared memory-segment is created with owner-only
+        access by default, unless otherwise requested by the mode word for units
+        &ge;2. Units 0 and 1 are always created with owner-only access for
+        backward compatibility.
+	</p>
+
 
         <h4>Structure of shared memory-segment</h4>
         <pre>struct shmTime {
@@ -49,14 +59,14 @@
 
         <h4>Operation mode=0</h4>
         <p>Each second, the value of <code>valid</code> of the shared memory-segment is checked:</p>
-        <p>If set, the values in the record (clockTimeStampSec, clockTimeStampUSec, receiveTimeStampSec, receiveTimeStampUSec, leap, precision) are passed to ntp, and <code>valid</code> is cleared and <code>count</code> is bumped.</p>
+        <p>If set, the values in the record (clockTimeStampSec, clockTimeStampUSec, receiveTimeStampSec, receiveTimeStampUSec, leap, precision) are passed to <i>NTPD</i>, and <code>valid</code> is cleared and <code>count</code> is bumped.</p>
         <p>If not set, <code>count</code> is bumped.</p>
         <h4>Operation mode=1</h4>
         <p>Each second, <code>valid</code> in the shared memory-segment is checked:</p>
-        <p>If set, the <code>count</code> field of the record is remembered, and the values in the record (clockTimeStampSec, clockTimeStampUSec, receiveTimeStampSec, receiveTimeStampUSec, leap, precision) are read. Then, the remembered <code>count</code> is compared to current value of <code>count</code> now in the record. If both are equal, the values read from the record are passed to ntp. If they differ, another process has modified the record while it was read out (was not able to produce this case), and failure is reported to ntp. The <code>valid</code> flag is cleared and <code>count</code> is bumped.</p>
+        <p>If set, the <code>count</code> field of the record is remembered, and the values in the record (clockTimeStampSec, clockTimeStampUSec, receiveTimeStampSec, receiveTimeStampUSec, leap, precision) are read. Then, the remembered <code>count</code> is compared to current value of <code>count</code> now in the record. If both are equal, the values read from the record are passed to <i>NTPD</i>. If they differ, another process has modified the record while it was read out (was not able to produce this case), and failure is reported to <i>NTPD</i>. The <code>valid</code> flag is cleared and <code>count</code> is bumped.</p>
         <p>If not set, <code>count</code> is bumped</p>
 
-<h4>Mode-independent postprocessing</h4>
+<h4>Mode-independent post-processing</h4>
 After the time stamps have been successfully plucked from the SHM
 segment, some sanity checks take place:
 <ul>
@@ -69,30 +79,38 @@ segment, some sanity checks take place:
   set to 1.
 </ul>
 
-<h4>gpsd</h4>
+<h4>GPSD</h4>
 
-<a href="http://gpsd.berlios.de/"><i>gpsd</i></a>
+<a href="http://gpsd.berlios.de/"><i>GPSD</i></a>
 knows how to talk to many GPS devices.
-It can work with <i>ntpd</i> through the SHM driver.
+It can work with <i>NTPD</i> through the SHM driver.
 <P>
-The <i>gpsd</i> man page suggests setting minpoll and maxpoll to 4.
+The <i>GPSD</i> man page suggests setting minpoll and maxpoll to 4.
 That was an attempt to reduce jitter.
 The SHM driver was fixed (ntp-4.2.5p138) to collect data each second rather than
 once per polling interval so that suggestion is no longer reasonable.
 <P>
-  <b>Note:</b> The GPSD client driver (type 46) uses the <i>gpsd</i>
-  client protocol to connect and talk to <i>gpsd</i>, but using the
-  SHM driver is the ancient way to have <i>gpsd</i> talk to <i>ntpd</i>.
+  <b>Note:</b> The <i>GPSD</i> client driver (type 46) uses the <i>GPSD</i>
+  client protocol to connect and talk to <i>GPSD</i>, but using the
+  SHM driver is the ancient way to have <i>GPSD</i> talk to <i>NTPD</i>. There
+  are some tricky points when using the SHM interface to interface
+  with <i>GPSD</i>, because <i>GPSD</i> will use two SHM clocks, one for the
+  serial data stream and one for the PPS information when
+  available. Receivers with a loose/sloppy timing between PPS and serial data
+  can easily cause trouble here because <i>NTPD</i> has no way to join the two
+  data streams and correlate the serial data with the PPS events.
+</p>
+<p>
 
 <h4>Clockstats</h4>
 If flag4 is set when the driver is polled, a clockstats record is written.
 The first 3 fields are the normal date, time, and IP address common to all clockstats records.
 <P>
 The 4th field is the number of second ticks since the last poll.
-The 5th field is the number of good data samples found.  The last 64 will be used by ntpd.
+The 5th field is the number of good data samples found.  The last 64 will be used by <i>NTPD</i>.
 The 6th field is the number of sample that didn't have valid data ready.
 The 7th field is the number of bad samples.
-The 8th field is the number of times the the mode 1 info was update while nptd was trying to grab a sample.
+The 8th field is the number of times the the mode 1 info was update while <i>NTPD</i> was trying to grab a sample.
 <P>
 
 Here is a sample showing the GPS reception fading out:
@@ -112,6 +130,39 @@ Here is a sample showing the GPS reception fading out:
 54364 85700.160 127.127.28.0  65   0  65   0   0
 </pre>
 
+    <h4>The 'mode' word</h4>
+    
+    <p>
+      Some aspects of the driver behavior can be adjusted by setting bits of
+      the 'mode' word in the server configuration line:<br>
+      &nbsp;&nbsp;<tt>server 127.127.28.</tt><i>x</i><tt> mode </tt><i>Y</i>
+    </p>
+
+    <table border="1" width="100%">
+      <caption>mode word bits and bit groups</caption>
+      <tbody><tr>
+	<th align="center">Bit</th>
+	<th align="center">Dec</th>
+	<th align="center">Hex</th>
+	<th align="left">Meaning</th>
+      </tr>
+      
+      <tr>
+	<td align="center">0</td>
+	<td align="center">1</td>
+	<td align="center">1</td>
+	<td>The SHM segment is private (mode 0600). This is the fixed
+	default for clock units 0 and 1; clock units &gt;1 are mode
+	0666 unless this bit is set for the specific unit.</td>
+      </tr><tr>
+	<td align="center">1-31</td>
+	<td align="center">-</td>
+	<td align="center">-</td>
+	<td><i>reserved -- do not use</i></td>
+	</tr>
+      </tbody>
+      </table>
+    
 	<h4>Fudge Factors</h4>
         <dl>
             <dt><tt>time1 <i>time</i></tt>
@@ -136,9 +187,64 @@ Here is a sample showing the GPS reception fading out:
             <dd>Not used by this driver.
             <dt><tt>flag4 0 | 1</tt>
             <dd>If flag4 is set, clockstats records will be written when the driver is polled.
-            <h4>Additional Information</h4>
-            <p><a href="../refclock.html">Reference Clock Drivers</a></p>
         </dl>
+
+	<h4>Public vs. Private SHM segments</h4>
+
+	<p>The driver attempts to create a shared memory segment with an
+	  identifier depending on the unit number. This identifier (which can be
+	  a numeric value or a string) clearly depends on the method used, which
+	  in turn depends on the host operating system:</p>
+
+	<ul>
+	  <li><p>
+	      <tt>Windows</tt> uses a file mapping to the page file with the
+	      name '<tt>Global\NTP</tt><i>u</i>' for public accessible
+	      mappings, where <i>u</i> is the clock unit. Private /
+	      non-public mappings are created as
+	      '<tt>Local\NTP</tt><i>u</i>'.
+	    </p><p>
+	      Public access assigns a NULL DACL to the memory mapping, while
+	      private access just uses the default DACL of the process creating
+	      the mapping.
+	    </p> 
+	  </li>
+	  <li><p>
+	      <tt>SYSV IPC</tt> creates a shared memory segment with a key value
+	      of <tt>0x4E545030</tt> + <i>u</i>, where <i>u</i> is again
+	      the clock unit. (This value could be hex-decoded as 'NTP0',
+	      'NTP1',..., with funny characters for units &gt; 9.)
+	    </p><p>
+	      Public access means a permission set of 0666, while private access
+	      creates the mapping with a permission set of 0600.
+	    </p>
+	  </li>
+	</ul>
+	
+	<p>There's no support for POSIX shared memory yet.</p>
+
+	<p><i>NTPD</i> is started as root on most POSIX-like operating systems
+	and uses the setuid/setgid system API to run under reduced rights once
+	the initial setup of the process is done. One consequence out of this
+	is that the allocation of SHM segments must be done early during the
+	clock setup. The actual polling of the clock is done as the run-time
+	user; deferring the creation of the SHM segment to this point will
+	create a SHM segment owned by the runtime-user account. The internal
+	structure of <i>NTPD</i> does not permit the use of a fudge flag if
+	this is to be avoided; this is the reason why a mode bit is used for
+	the configuration of a public segment.
+	</p>
+	
+	<p>When running under Windows, the chosen user account must be able to
+	create a SHM segment in the global object name space for SHM clocks with
+	public access. Otherwise the session isolation used by Windows kernels
+	after WinXP will get into the way if the client program does not run in
+	the same session.
+	</p>
+
+        <h4>Additional Information</h4>
+        <p><a href="../refclock.html">Reference Clock Drivers</a></p>
+
         <hr>
         <script type="text/javascript" language="javascript" src="scripts/footer.txt"></script>
     </body>
diff --git a/html/miscopt.html b/html/miscopt.html
index 62f41b6..5750d17 100644
--- a/html/miscopt.html
+++ b/html/miscopt.html
@@ -10,7 +10,7 @@
 <img src="pic/boom3.gif" alt="gif" align="left"><a href="http://www.eecis.udel.edu/~mills/pictures.html">from <i>Pogo</i>, Walt Kelly</a>
 <p>We have three, now looking for more.</p>
 <p>Last update:
-  <!-- #BeginDate format:En2m -->31-Jan-2014  06:54<!-- #EndDate -->
+  <!-- #BeginDate format:En2m -->28-Feb-2015  12:01<!-- #EndDate -->
     UTC</p>
 <br clear="left">
 <h4>Related Links</h4>
@@ -90,7 +90,7 @@
     </dl>
   </dd>
   <dt id="nonvolatile"><tt>nonvolatile <i>threshold</i></tt></dt>
-  <dd>Specify the <i><tt>threshold</tt></i> in PPM to write the frequency file, with default 0.1 PPM. The frequency file is inspected each hour. If the difference between the current frequency  and the last value written exceeds the threshold, the file is written and the <tt><em>threshold</em></tt>  becomes the new threshold value. If the threshold is not exceeded, it is reduced by half. This is intended to reduce the frequency of unnecessary file writes for embedded systems with nonvolatile memory.</dd>
+  <dd>Specify the <i><tt>threshold</tt></i> in seconds to write the frequency file, with default of 1e-7 (0.1 PPM). The frequency file is inspected each hour. If the difference between the current frequency  and the last value written exceeds the threshold, the file is written and the <tt><em>threshold</em></tt>  becomes the new threshold value. If the threshold is not exceeded, it is reduced by half. This is intended to reduce the frequency of unnecessary file writes for embedded systems with nonvolatile memory.</dd>
   <dt id="phone"><tt>phone <i>dial</i> ...</tt></dt>
   <dd>This command is used in conjunction with the ACTS modem driver (type 18). The arguments consist of a maximum of 10 telephone numbers used to dial USNO, NIST or European time services. The Hayes command ATDT&nbsp;is normally prepended to the number, which can contain other modem control codes as well.</dd>
   <dt id="reset"><tt>reset [allpeers] [auth] [ctl] [io] [mem] [sys] [timer]</tt></dt>
diff --git a/html/sntp.html b/html/sntp.html
index 0c270cb..84c6f29 100644
--- a/html/sntp.html
+++ b/html/sntp.html
@@ -3,6 +3,7 @@
 <head>
 <meta http-equiv="content-type" content="text/html;charset=iso-8859-1">
 <title>sntp - Simple Network Time Protocol (SNTP) Client</title>
+<!-- Changed by: Harlan &, 07-Dec-2014 -->
 <link href="scripts/style.css" type="text/css" rel="stylesheet">
 </head>
 <body>
@@ -10,7 +11,7 @@
 <img src="pic/dogsnake.gif" alt="gif" align="left"><a href="http://www.eecis.udel.edu/~mills/pictures.html">from <i>Alice's Adventures in Wonderland</i>, Lewis Carroll</a>
 <p>S is for snakeoil.</p>
 <p>Last update:
-  <!-- #BeginDate format:En2m -->3-Oct-2011  21:51<!-- #EndDate -->
+  <!-- #BeginDate format:En2m -->1-Apr-2015  11:05<!-- #EndDate -->
   UTC</p>
 <br clear="left">
 <hr>
@@ -19,8 +20,8 @@
 <h4>Description</h4>
 <p>This program is a Simple Network Time Protocol (SNTP) client that can be used to query a Network Time Protocol (NTP) server and display the time offset of the system clock relative to the server clock. Run as root it can correct the system clock to this offset as well. It can be run as an interactive command or from a script by a <tt>cron</tt> job. The program implements the SNTP client protocol defined in RFC 5905, including the full on-wire protocol but does not provide the sanity checks, access controls, security functions and mitigation algorithms as in the full NTP version 4 specification, also defined in RFC 5905.</p>
 <p>By default, <tt>sntp</tt> writes the local date and time (i.e., not UTC) to the standard output in the format</p>
-<p><tt>2011-08-04 00:40:36.642222 (+0000) +0.006611 +/- 0.041061  psp-os1 149.20.68.26</tt></p>
-<p>where the <tt>+0.006611 +/- 0.041061</tt> indicates the time offset and error bound of the system clock relative to the server clock, in seconds.</p>
+<p><tt>2011-08-04 00:40:36.642222 (+0000) +0.006611 +/- 0.041061  psp-os1 149.20.68.26 s3 no-leap</tt></p>
+<p>where the <tt>+0.006611 +/- 0.041061</tt> indicates the time offset and error bound of the system clock relative to the server clock, in seconds.  The hostname and/or the IP is displayed, as is the stratum of the server.  Finally, the leap indicator status is displayed.</p>
 <p>If -b <i>bcaddress</i> is not specified, the program sends a single message to each address and waits up to <i>uctimeout</i> (default 5) seconds for a unicast server response. Otherwise, it sends no message and waits up to <i>bctimeout</i> (default 68) seconds for a broadcast NTP message.</p>
 <h4>Options</h4>
 <p><tt>sntp</tt> recognizes the following options:</p>
@@ -46,7 +47,7 @@
   <dt><tt>-g <i>delay</i>, --gap <i>delay</i></tt></dt>
   <dd>Specify the <i>delay</i> in milliseconds between outgoing queries, defaulting to 50.  <tt>sntp</tt> sends queries to all provided hostnames/addresses in short succession, and by default terminates once the first valid response is received.  With multiple time sources provided, all but one will not be used.  To limit the number of queries whose responses will not be used, each query is separated from the preceding one by <i>delay</i> milliseconds, to allow time for responses to earlier queries to be received.  A larger <i>delay</i> reduces the query load on the time sources, increasing the time to receive a valid response if the first source attempted is slow or unreachable.</dd>
   <dt><tt>-K <i>kodfile</i>, --kod <i>kodfile</i></tt></dt>
-  <dd>Specifies the filename <i>kodfile</i> to be used for the persistent history of KoD (Kiss Of Death, or rate-limiting) responses received from servers.  The default is <tt>/var/db/ntp-kod</tt>.  Note that the short option is <tt>-K</tt>, an uppercase letter K.</dd>
+  <dd>Specifies the filename <i>kodfile</i> to be used for the persistent history of KoD (Kiss Of Death, or rate-limiting) responses received from servers.  The default is <tt>/var/db/ntp-kod</tt>.  If the file does not exist, a warning message will be displayed.  The file will not be created.  Note that the short option is <tt>-K</tt>, an uppercase letter K.</dd>
   <dt><tt>-k <i>keyfile</i>, --keyfile <i>keyfile</i></tt></dt>
   <dd>Specifies the filename <i>keyfile</i> used with the <tt>-a</tt>/<tt>--authentication</tt> option.  The format of the file is described on the <a href="keygen.html"><tt>ntp-keygen</tt> page</a>.</dd>
   <dt><tt>-l <i>logfile</i>, --filelog <i>logfile</i></tt></dt>