1/* -*- Mode: Text -*- */
2
3autogen definitions options;
4
5#include autogen-version.def
6#include copyright.def
7
8prog-name      = "sntp";
9prog-title          = "standard Simple Network Time Protocol client program";
10argument  = '[ hostname-or-IP ...]';
11
12#include homerc.def
13
14long-opts;
15
16config-header       = "config.h";
17
18environrc;
19
20#include version.def
21
22flag = {
23  name              = ipv4;
24  value             = 4;
25  flags-cant        = ipv6;
26  descrip = "Force IPv4 DNS name resolution";
27  doc               = <<- _EndOfDoc_
28          Force DNS resolution of the following host names on the command line
29          to the IPv4 namespace.
30          _EndOfDoc_;
31};
32
33flag = {
34  name              = ipv6;
35  value             = 6;
36  flags-cant        = ipv4;
37  descrip = "Force IPv6 DNS name resolution";
38  doc               = <<- _EndOfDoc_
39          Force DNS resolution of the following host names on the command line
40          to the IPv6 namespace.
41          _EndOfDoc_;
42};
43
44flag = {
45  name              = authentication;
46  value             = a;
47  descrip = "Enable authentication with the key @var{auth-keynumber}";
48  arg-type          = number;
49  arg-name          = "auth-keynumber";
50  doc               = <<- _EndOfDoc_
51          Enable authentication using the key specified in this option's
52          argument.  The argument of this option is the @option{keyid}, a
53          number specified in the @option{keyfile} as this key's identifier.
54          See the @option{keyfile} option (@option{-k}) for more details.
55          _EndOfDoc_;
56};
57
58flag = {
59  name              = broadcast;
60  value             = b;
61  descrip = "Listen to the address specified for broadcast time sync";
62  arg-type          = string;
63  arg-name          = "broadcast-address";
64  max                = NOLIMIT;
65  stack-arg;
66  doc               = <<- _EndOfDoc_
67          If specified @code{sntp} will listen to the specified address
68          for NTP broadcasts.  The default maximum wait time
69          can (and probably should) be modified with @option{-t}.
70          _EndOfDoc_;
71};
72
73flag = {
74  name              = concurrent;
75  value             = c;
76  descrip = "Concurrently query all IPs returned for host-name";
77  arg-type          = string;
78  arg-name          = "host-name";
79  max               = NOLIMIT;
80  stack-arg;
81  doc               = <<- _EndOfDoc_
82          Requests from an NTP "client" to a "server" should never be sent
83          more rapidly than one every 2 seconds.  By default, any IPs returned
84          as part of a DNS lookup are assumed to be for a single instance of
85          @code{ntpd}, and therefore @code{sntp} will send queries to these IPs
86          one after another, with a 2-second gap in between each query.
87
88          The @option{-c} or @option{--concurrent} flag says that any IPs
89          returned for the DNS lookup of the supplied host-name are on
90          different machines, so we can send concurrent queries.
91          _EndOfDoc_;
92};
93
94#include debug-opt.def
95
96flag = {
97  name              = gap;
98  value             = g;
99  descrip = "The gap (in milliseconds) between time requests";
100  arg-type          = number;
101  arg-name          = "milliseconds";
102  arg-default       = 50;
103  doc               = <<- _EndOfDoc_
104          Since we're only going to use the first valid response we get and
105          there is benefit to specifying a good number of servers to query,
106          separate the queries we send out by the specified number of
107          milliseconds.
108          _EndOfDoc_;
109};
110
111flag = {
112  name              = kod;
113  value             = K;
114  arg-type          = file;
115  arg-name          = "file-name";
116  arg-default       = "/var/db/ntp-kod";
117  descrip = "KoD history filename";
118  doc               = <<- _EndOfDoc_
119          Specifies the filename to be used for the persistent history of KoD
120          responses received from servers.  If the file does not exist, a
121          warning message will be displayed.  The file will not be created.
122          _EndOfDoc_;
123};
124
125flag = {
126  name              = keyfile;
127  value             = k;
128  descrip = "Look in this file for the key specified with @option{-a}";
129  arg-type          = file;
130  arg-name          = "file-name";
131  arg-default       = "/etc/ntp.keys";
132  doc               = <<- _EndOfDoc_
133          This option specifies the keyfile.
134          @code{sntp} will search for the key specified with @option{-a}
135          @file{keyno} in this file.  See @command{ntp.keys(5)} for more
136          information.
137          _EndOfDoc_;
138};
139
140flag = {
141  name              = logfile;
142  value             = l;
143  arg-type          = file;
144  arg-name          = "file-name";
145  descrip = "Log to specified logfile";
146  doc               = <<- _EndOfDoc_
147          This option causes the client to write log messages to the specified
148          @file{logfile}.
149          _EndOfDoc_;
150};
151
152flag = {
153  name              = steplimit;
154  value             = M;
155  arg-type          = number;
156  arg-range         = "0->";
157  descrip = "Adjustments less than @var{steplimit} msec will be slewed";
158  doc               = <<- _EndOfDoc_
159          If the time adjustment is less than @file{steplimit} milliseconds,
160          slew the amount using @command{adjtime(2)}.  Otherwise, step the
161          correction using @command{settimeofday(2)}.  The default value is 0,
162          which means all adjustments will be stepped.  This is a feature, as
163          different situations demand different values.
164          _EndOfDoc_;
165};
166
167flag = {
168  name              = ntpversion;
169  value             = o;
170  descrip = "Send @var{int} as our NTP protocol version";
171  arg-type          = number;
172  arg-default       = 4;
173  arg-range         = "0->7";
174  doc               = <<- _EndOfDoc_
175          When sending requests to a remote server, tell them we are running
176          NTP protocol version @file{ntpversion} .
177          _EndOfDoc_;
178};
179
180flag = {
181  name              = usereservedport;
182  value             = r;
183  descrip = "Use the NTP Reserved Port (port 123)";
184  doc               = <<- _EndOfDoc_
185          Use port 123, which is reserved for NTP, for our network
186          communications.
187          _EndOfDoc_;
188};
189
190flag = {
191  name              = step;
192  value             = S;
193  descrip = "OK to 'step' the time with @command{settimeofday(2)}";
194  doc               = <<- _EndOfDoc_
195          _EndOfDoc_;
196};
197
198flag = {
199  name              = slew;
200  value             = s;
201  descrip = "OK to 'slew' the time with @command{adjtime(2)}";
202  doc               = <<- _EndOfDoc_
203          _EndOfDoc_;
204};
205
206
207flag = {
208  name              = timeout;
209  value             = t;
210  descrip = "The number of seconds to wait for responses";
211  arg-type          = number;
212  arg-name          = "seconds";
213  arg-default       = 5;
214  doc               = <<- _EndOfDoc_
215          When waiting for a reply, @code{sntp} will wait the number
216          of seconds specified before giving up.  The default should be
217          more than enough for a unicast response.  If @code{sntp} is
218          only waiting for a broadcast response a longer timeout is
219          likely needed.
220          _EndOfDoc_;
221};
222
223flag = {
224  name              = "wait";
225  descrip = "Wait for pending replies (if not setting the time)";
226  disable = no;
227  enabled;
228  settable;
229  doc               = <<- _EndOfDoc_
230          If we are not setting the time, wait for all pending responses.
231          _EndOfDoc_;
232};
233
234/* explain: Additional information whenever the usage routine is invoked */
235explain = <<- _END_EXPLAIN
236          _END_EXPLAIN;
237
238doc-section         = {
239  ds-type = 'DESCRIPTION';
240  ds-format         = 'mdoc';
241  ds-text = <<- _END_PROG_MDOC_DESCRIP
242.Nm
243can be used as an SNTP client to query a NTP or SNTP server and either display
244the time or set the local system's time (given suitable privilege).  It can be
245run as an interactive command or from a
246.Ic cron
247job.
248
249NTP (the Network Time Protocol) and SNTP (the Simple Network Time Protocol)
250are defined and described by RFC 5905.
251
252.Pp
253The default is to write the estimated correct local date and time (i.e. not
254UTC) to the standard output in a format like:
255
256.Ic "'1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 [host] IP sN'"
257
258where the
259.Ic "'(+0800)'"
260means that to get to UTC from the reported local time one must
261add 8 hours and 0 minutes,
262the
263.Ic "'+4.567'"
264indicates the local clock is 4.567 seconds behind the correct time
265(so 4.567 seconds must be added to the local clock to get it to be correct).
266Note that the number of decimals printed for this value will change
267based on the reported precision of the server.
268.Ic "'+/- 0.089'"
269is the reported
270.Em synchronization distance
271(in seconds), which represents the maximum error due to all causes.
272If the server does not report valid data needed to calculate the
273synchronization distance, this will be reported as
274.Ic "'+/- ?'" .
275If the
276.Em host
277is different from the
278.Em IP ,
279both will be displayed.
280Otherwise, only the
281.Em IP
282is displayed.
283Finally, the
284.Em stratum
285of the host is reported
286and the leap indicator is decoded and displayed.
287          _END_PROG_MDOC_DESCRIP;
288};
289
290doc-section         = {
291  ds-type = 'USAGE';
292  ds-format         = 'mdoc';
293  ds-text = <<- _END_MDOC_USAGE
294.Bl -tag -width indent
295.It Li "sntp ntpserver.somewhere"
296is the simplest use of this program
297and can be run as an unprivileged command
298to check the current time and error in the local clock.
299.It Li "sntp -Ss -M 128 ntpserver.somewhere"
300With suitable privilege,
301run as a command
302or from a
303.Xr cron 8
304job,
305.Ic "sntp -Ss -M 128 ntpserver.somewhere"
306will request the time from the server,
307and if that server reports that it is synchronized
308then if the offset adjustment is less than 128 milliseconds
309the correction will be slewed,
310and if the correction is more than 128 milliseconds
311the correction  will be stepped.
312.It Li "sntp -S ntpserver.somewhere"
313With suitable privilege,
314run as a command
315or from a
316.Xr cron 8
317job,
318.Ic "sntp -S ntpserver.somewhere"
319will set (step) the local clock from a synchronized specified server,
320like the (deprecated)
321.Xr ntpdate 1ntpdatemdoc ,
322or
323.Xr rdate 8
324commands.
325.El
326          _END_MDOC_USAGE;
327};
328
329doc-section         = {
330  ds-type = 'AUTHORS';
331  ds-format         = 'mdoc';
332  ds-text = <<- _END_MDOC_AUTHORS
333.An "Johannes Maximilian Kuehn"
334.An "Harlan Stenn"
335.An "Dave Hart"
336          _END_MDOC_AUTHORS;
337};
338