xref: /freebsd/lib/libutil/login_times.3 (revision fa9896e082a1046ff4fbc75fcba4d18d1f2efc19)
1.\" Copyright (c) 1995 David Nugent <davidn@blaze.net.au>
2.\" All rights reserved.
3.\"
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13.\" 3. This work was done expressly for inclusion into FreeBSD.  Other use
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15.\" 4. Absolutely no warranty of function or purpose is made by the author
16.\"    David Nugent.
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20.Dd May 10, 2020
21.Dt LOGIN_TIMES 3
22.Os
23.Sh NAME
24.Nm parse_lt ,
25.Nm in_lt ,
26.Nm in_ltm ,
27.Nm in_ltms ,
28.Nm in_lts
29.Nd functions for parsing and checking login time periods
30.Sh LIBRARY
31.Lb libutil
32.Sh SYNOPSIS
33.In sys/types.h
34.In time.h
35.In login_cap.h
36.Ft login_time_t
37.Fn parse_lt "const char *str"
38.Ft int
39.Fn in_lt "const login_time_t *lt" "time_t *ends"
40.Ft int
41.Fn in_ltm "const login_time_t *lt" "struct tm *t" "time_t *ends"
42.Ft int
43.Fn in_ltms "const login_time_t *lt" "struct tm *t" "time_t *ends"
44.Ft int
45.Fn in_lts "const login_time_t *lt" "time_t *ends"
46.Sh DESCRIPTION
47This set of functions may be used for parsing and checking login and
48session times against a predefined list of allowed login times as
49used in
50.Xr login.conf 5 .
51.Pp
52The format of allowed and disallowed session times specified in the
53.Ar times.allow
54and
55.Ar times.deny
56capability fields in a login class are comprised of a prefix which
57specifies one or more 2- or 3-character day codes, followed by
58a start and end time in 24 hour format separated by a hyphen.
59Day codes may be concatenated together to select specific days, or
60the special mnemonics "Any" and "All" (for any/all days of the week),
61"Wk" for any day of the week (excluding Saturdays and Sundays) and
62"Wd" for any weekend day may be used.
63.Pp
64For example, the following time period:
65.Dl MoThFrSa1400-2200
66is interpreted as Monday, Thursday through Saturday between the hours
67of 2pm and 10pm.
68.Dl Wd0600-1800
69means Saturday and Sunday, between the hours of 6am through 6pm, and
70.Dl Any0400-1600
71means any day of the week, between 4am and 4pm.
72.Pp
73Note that all time periods reference system local time.
74.Pp
75The
76.Fn parse_lt
77function converts the ASCII representation of a time period into
78a structure of type
79.Ft login_time_t .
80This is defined as:
81.Bd -literal
82typedef struct login_time
83{
84  u_short	lt_start;   /* Start time */
85  u_short	lt_end;	    /* End time */
86  u_char	lt_dow;	    /* Days of week */
87} login_time_t;
88.Ed
89.Pp
90The
91.Ar lt_start
92and
93.Ar lt_end
94fields contain the number of minutes past midnight at which the
95described period begins and ends.
96The
97.Ar lt_dow
98field is a bit field, containing one bit for each day of the week
99and one bit unused.
100A series
101.Em LTM_*
102macros may be used for testing bits individually and in combination.
103If no bits are set in this field - i.e., it contains the value
104.Em LTM_NONE
105- then the entire period is assumed invalid.
106This is used as a convention to mark the termination of an array
107of login_time_t values.
108If
109.Fn parse_lt
110returns a
111.Ar login_time_t
112with
113.Ar lt_dow
114equal to
115.Em LTM_NONE
116then a parsing error was encountered.
117.Pp
118The remaining functions provide the ability to test a given time_t or
119struct tm value against a specific time period or array of time
120periods.
121The
122.Fn in_ltm
123function determines whether the given time described by the struct tm
124passed as the second parameter falls within the period described
125by the first parameter.
126A boolean value is returned, indicating whether or not the time
127specified falls within the period.
128If the time does fall within the time period, and the third
129parameter to the function is not NULL, the time at which the
130period ends relative to the time passed is returned.
131.Pp
132The
133.Fn in_ltms
134function is similar to
135.Fn in_ltm
136except that the first parameter must be a pointer to an array
137of login_time_t objects, which is up to LC_MAXTIMES (64)
138elements in length, and terminated by an element with its
139.Ar lt_dow
140field set to
141.Em LTM_NONE .
142.Pp
143The
144.Fn in_lt
145and
146.Fn in_lts
147functions are equivalent to
148.Fn in_ltm
149and
150.Fn in_ltms ,
151respectively, with the second argument set to the current time as
152returned by
153.Xr localtime 3 .
154.Sh RETURN VALUES
155The
156.Fn parse_lt
157function returns a filled in structure of type login_time_t containing the
158parsed time period.
159If a parsing error occurs, the lt_dow field is set to
160.Em LTM_NONE
161(i.e., 0).
162.Pp
163The
164.Fn in_ltm
165function returns non-zero if the given time falls within the period described
166by the login_time_t passed as the first parameter.
167.Pp
168The
169.Fn in_ltms
170function returns the index of the first time period found in which the given
171time falls, or -1 if none of them apply.
172.Sh SEE ALSO
173.Xr getcap 3 ,
174.Xr login_cap 3 ,
175.Xr login_class 3 ,
176.Xr login.conf 5 ,
177.Xr termcap 5
178.Sh HISTORY
179The functions
180.Fn parse_lt ,
181.Fn in_lt ,
182.Fn in_ltm ,
183.Fn in_ltms
184and
185.Fn in_lts
186first appeared in
187.Fx 2.1.5 .
188