NetBSD/lib/libutil/login_cap.3

.\" $NetBSD: login_cap.3,v 1.6 2000/10/10 13:17:28 itojun Exp $
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.\" BSDI login_cap.3,v 1.4 1997/11/07 16:22:27 jch Exp
.\"
.Dd "January 13, 2000"
.Dt LOGIN_CAP 3 
.Os
.Sh NAME
.Nm login_getclass ,
.Nm login_getcapbool ,
.Nm login_getcapnum ,
.Nm login_getcapsize ,
.Nm login_getcapstr ,
.Nm login_getcaptime ,
.Nm login_close ,
.Nm setclasscontext ,
.Nm setusercontext
.Nd query login.conf database about a user class
.Sh LIBRARY
.Lb libutil
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <login_cap.h>
.Ft login_cap_t *
.Fn login_getclass "char *class"
.Ft int
.Fn login_getcapbool "login_cap_t *lc" "char *cap" "u_int def"
.Ft quad_t
.Fn login_getcapnum "login_cap_t *lc" "char *cap" "quad_t def" "quad_t err"
.Ft quad_t
.Fn login_getcapsize "login_cap_t *lc" "char *cap" "quad_t def" "quad_t err"
.Ft char *
.Fn login_getcapstr "login_cap_t *lc" "char *cap" "char *def" "char *err"
.Ft quad_t
.Fn login_getcaptime "login_cap_t *lc" "char *cap" "quad_t def" "quad_t err"
.Ft void
.Fn login_close "login_cap_t *lc"
.Ft int
.Fn setclasscontext "char *class" "u_int flags"
.Ft int
.Fn setusercontext "login_cap_t *lc" "struct passwd *pwd" "uid_t uid" "u_int flags"
.Sh DESCRIPTION
The
.Fn login_getclass
function extracts the entry specified by
.Ar class
(or
.Li default
if
.Ar class
is NULL or the empty string)
from
.Pa /etc/login.conf
(see
.Xr login.conf 5 ) .
If the entry is found, a
.Li login_cap_t
pointer is returned.
NULL is returned if the user class is not found.
When the
.Li login_cap_t
structure is no longer needed, is should be freed by the
.Fn login_close
function.
.Pp
Once
.Ar lc
has been returned by
.Fn login_getclass ,
any of the other
.Fn login_*
functions may be called.
.Pp
The
.Fn login_getcapnum ,
.Fn login_getcapsize ,
.Fn login_getcapstr ,
and
.Fn login_getcaptime
functions all query the database entry for a field named
.Ar cap .
If the field is found, its value is returned.  If the field is not
found, the value specified by
.Ar def
is returned.
If an error is encountered while trying to find the field,
.Ar err
is returned.
See
.Xr login.conf 5
for a discussion of the various textual forms the value may take.
The
.Fn login_getcapbool
function is slightly different.  It returns
.Ar def
if no capabilities were found for this class (typically meaning that
the default class was used and the
.Li /etc/login.conf
file is missing).
It returns a non-zero value if 
.Ar cap ,
with no value, was found,
zero otherwise.
.Pp
The
.Fn setclasscontext
function takes
.Ar class ,
the name of a user class,
and sets the resources defined by that class according to
.Ar flags.
Only the
.Nm LOGIN_SETPATH ,
.Nm LOGIN_SETPRIORITY ,
.Nm LOGIN_SETRESOURCES ,
and
.Nm LOGIN_SETUMASK
bits are used.  (See 
.Fn setusercontext
below).
It returns 0 on success and -1 on failure.
.Pp
The
.Fn setusercontext
function
sets the resources according to
.Ar flags .
The
.Ar lc
argument, if not NULL, contains the class information that should
be used.
The
.Ar pwd
argument, if not NULL, provides information about the user.
Both
.Ar lc
and
.Ar pwd
cannot be NULL.
The
.Ar uid
argument is used in place of the user id contained in the
.Ar pwd
structure when calling
.Xr setuid 2 .
The various bits available to be or-ed together to make up
.Ar flags
are:
.Bl -tag -width LOGIN_SETRESOURCESXX
.It LOGIN_SETGROUP
Set the group id and call
.Xr initgroups 3 .
Requires the
.Xr pwd
field be specified.
.It LOGIN_SETLOGIN
Sets the login name by
.Xr setlogin 2 .
Requires the
.Ar pwd
field be specified.
.It LOGIN_SETPATH
Sets the
.Ev PATH
environment variable.
.It LOGIN_SETPRIORITY
Sets the priority by
.Xr setpriority 2 .
.It LOGIN_SETRESOURCES
Sets the various system resources by
.Xr setrlimit 2 .
.It LOGIN_SETUMASK
Sets the umask by
.Xr umask 2 .
.It LOGIN_SETUSER
Sets the user id to
.Ar uid
by
.Xr setuid 2 .
.It LOGIN_SETENV
Sets the environment variables as defined by the setenv keyword, by
.Xr setenv 3 .
.It LOGIN_SETALL
Sets all of the above.
.El
.Sh SEE ALSO
.Xr setlogin 2 ,
.Xr setpriority 2 ,
.Xr setrlimit 2 ,
.Xr setuid 2 ,
.Xr umask 2 ,
.Xr initgroups 3 ,
.Xr secure_path 3 ,
.Xr login.conf 5
.Sh HISTORY
The
.Nm
family of functions are largely based on the
.Bsx
implementation of same, and appeared in
.Nx 1.5
by kind permission.