LOGIN_CLASS(3) BSD Library Functions Manual LOGIN_CLASS(3)NAME
setclasscontext, setclassenvironment, setclassresources, setusercontext —
functions for using the login class capabilities database
LIBRARY
System Utilities Library (libutil, -lutil)
SYNOPSIS
#include <sys/types.h>
#include <login_cap.h>
int
setclasscontext(const char *classname, unsigned int flags);
int
setusercontext(login_cap_t *lc, const struct passwd *pwd, uid_t uid,
unsigned int flags);
void
setclassresources(login_cap_t *lc);
int
setclassenvironment(login_cap_t *lc, const struct passwd *pwd,
int paths);
DESCRIPTION
These functions provide a higher level interface to the login class data‐
base than those documented in login_cap(3). These functions are used to
set resource limits, environment and accounting settings for users on
logging into the system and when selecting an appropriate set of environ‐
ment and resource settings for system daemons based on login classes.
These functions may only be called if the current process is running with
root privileges. If the LOGIN_SETLOGIN flag is used this function calls
setlogin(2), and due care must be taken as detailed in the manpage for
that function and this affects all processes running in the same session
and not just the current process.
setclasscontext() sets various class context values (resource limits,
umask and process priorities) based on values for a specific named class.
The function setusercontext() sets class context values based on a given
login_cap_t object, a specific passwd record (if login_cap_t is NULL),
sets the current session's login and the current process user and group
ownership. Each of these functions is selectable via bit-flags passed in
the flags parameter, which is comprised of one or more of the following:
LOGIN_SETLOGIN Set the login associated with the current session to
the user specified in the passwd structure.
setlogin(2). The pwd parameter must not be NULL if
this option is used.
LOGIN_SETUSER Set ownership of the current process to the uid spec‐
ified in the uid parameter using setuid(2).
LOGIN_SETGROUP Set group ownership of the current process to the
group id specified in the passwd structure using
setgid(2), and calls initgroups(3) to set up the
group access list for the current process. The pwd
parameter must not be NULL if this option is used.
LOGIN_SETRESOURCES Set resource limits for the current process based on
values specified in the system login class database.
Class capability tags used, with and without -cur
(soft limit) or -max (hard limit) suffixes and the
corresponding resource setting:
cputime RLIMIT_CPU
filesize RLIMIT_FSIZE
datasize RLIMIT_DATA
stacksize RLIMIT_STACK
coredumpsize RLIMIT_CORE
memoryuse RLIMIT_RSS
memorylocked RLIMIT_MEMLOCK
maxproc RLIMIT_NPROC
openfiles RLIMIT_NOFILE
sbsize RLIMIT_SBSIZE
vmemoryuse RLIMIT_VMEM
LOGIN_SETPRIORITY Set the scheduling priority for the current process
based on the value specified in the system login
class database. Class capability tags used:
priority
LOGIN_SETUMASK Set the umask for the current process to a value in
the user or system login class database. Class capa‐
bility tags used:
umask
LOGIN_SETPATH Set the "path" and "manpath" environment variables
based on values in the user or system login class
database. Class capability tags used with the corre‐
sponding environment variables set:
path PATH
manpath MANPATH
LOGIN_SETENV Set various environment variables based on values in
the user or system login class database. Class capa‐
bility tags used with the corresponding environment
variables set:
lang LANG
charset MM_CHARSET
timezone TZ
term TERM
Additional environment variables may be set using the
list type capability "setenv=var1 val1,var2
val2..,varN valN".
LOGIN_SETALL Enables all of the above settings.
Note that when setting environment variables and a valid passwd pointer
is provided in the pwd parameter, the characters ‘~’ and ‘$’ are substi‐
tuted for the user's home directory and login name respectively.
The setclassresources() and setclassenvironment() functions are subsets
of the setcontext functions above, but may be useful in isolation.
RETURN VALUESsetclassenvironment() , setclasscontext() and setusercontext() return -1
if an error occurred, or 0 on success. If an error occurs when attempt‐
ing to set the user, login, group or resources, a message is reported to
syslog(3), with LOG_ERR priority and directed to the currently active
facility.
ERRORS
[ENOMEM] The function setclassenvironment() failed because it
were unable to allocate memory for the environment.
SEE ALSOsetgid(2), setlogin(2), setuid(2), getcap(3), initgroups(3),
login_cap(3), login.conf(5), termcap(5)BSD December 28, 1996 BSD
