/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2011 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Edward Tomasz Napierala under sponsorship
* from the FreeBSD Foundation.
*
* 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 AUTHOR AND CONTRIBUTORS ``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 AUTHOR 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.
*
* $FreeBSD$
*/
/*
* Processes may set login class name using setloginclass(2). This
* is usually done through call to setusercontext(3), by programs
* such as login(1), based on information from master.passwd(5). Kernel
* uses this information to enforce per-class resource limits. Current
* login class can be determined using id(1). Login class is inherited
* from the parent process during fork(2). If not set, it defaults
* to "default".
*
* Code in this file implements setloginclass(2) and getloginclass(2)
* system calls, and maintains class name storage and retrieval.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/loginclass.h>
#include <sys/malloc.h>
#include <sys/types.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/racct.h>
#include <sys/rctl.h>
#include <sys/refcount.h>
#include <sys/rwlock.h>
#include <sys/sysproto.h>
#include <sys/systm.h>
static MALLOC_DEFINE(M_LOGINCLASS, "loginclass", "loginclass structures");
LIST_HEAD(, loginclass) loginclasses;
/*
* Lock protecting loginclasses list.
*/
static struct rwlock loginclasses_lock;
RW_SYSINIT(loginclasses_init, &loginclasses_lock, "loginclasses lock");
void
loginclass_hold(struct loginclass *lc)
{
refcount_acquire(&lc->lc_refcount);
}
void
loginclass_free(struct loginclass *lc)
{
if (refcount_release_if_not_last(&lc->lc_refcount))
return;
rw_wlock(&loginclasses_lock);
if (!refcount_release(&lc->lc_refcount)) {
rw_wunlock(&loginclasses_lock);
return;
}
racct_destroy(&lc->lc_racct);
LIST_REMOVE(lc, lc_next);
rw_wunlock(&loginclasses_lock);
free(lc, M_LOGINCLASS);
}
/*
* Look up a loginclass struct for the parameter name.
* loginclasses_lock must be locked.
* Increase refcount on loginclass struct returned.
*/
static struct loginclass *
loginclass_lookup(const char *name)
{
struct loginclass *lc;
rw_assert(&loginclasses_lock, RA_LOCKED);
LIST_FOREACH(lc, &loginclasses, lc_next)
if (strcmp(name, lc->lc_name) == 0) {
loginclass_hold(lc);
break;
}
return (lc);
}
/*
* Return loginclass structure with a corresponding name. Not
* performance critical, as it's used mainly by setloginclass(2),
* which happens once per login session. Caller has to use
* loginclass_free() on the returned value when it's no longer
* needed.
*/
struct loginclass *
loginclass_find(const char *name)
{
struct loginclass *lc, *new_lc;
if (name[0] == '\0' || strlen(name) >= MAXLOGNAME)
return (NULL);
lc = curthread->td_ucred->cr_loginclass;
if (strcmp(name, lc->lc_name) == 0) {
loginclass_hold(lc);
return (lc);
}
rw_rlock(&loginclasses_lock);
lc = loginclass_lookup(name);
rw_runlock(&loginclasses_lock);
if (lc != NULL)
return (lc);
new_lc = malloc(sizeof(*new_lc), M_LOGINCLASS, M_ZERO | M_WAITOK);
racct_create(&new_lc->lc_racct);
refcount_init(&new_lc->lc_refcount, 1);
strcpy(new_lc->lc_name, name);
rw_wlock(&loginclasses_lock);
/*
* There's a chance someone created our loginclass while we
* were in malloc and not holding the lock, so we have to
* make sure we don't insert a duplicate loginclass.
*/
if ((lc = loginclass_lookup(name)) == NULL) {
LIST_INSERT_HEAD(&loginclasses, new_lc, lc_next);
rw_wunlock(&loginclasses_lock);
lc = new_lc;
} else {
rw_wunlock(&loginclasses_lock);
racct_destroy(&new_lc->lc_racct);
free(new_lc, M_LOGINCLASS);
}
return (lc);
}
/*
* Get login class name.
*/
#ifndef _SYS_SYSPROTO_H_
struct getloginclass_args {
char *namebuf;
size_t namelen;
};
#endif
/* ARGSUSED */
int
sys_getloginclass(struct thread *td, struct getloginclass_args *uap)
{
struct loginclass *lc;
size_t lcnamelen;
lc = td->td_ucred->cr_loginclass;
lcnamelen = strlen(lc->lc_name) + 1;
if (lcnamelen > uap->namelen)
return (ERANGE);
return (copyout(lc->lc_name, uap->namebuf, lcnamelen));
}
/*
* Set login class name.
*/
#ifndef _SYS_SYSPROTO_H_
struct setloginclass_args {
const char *namebuf;
};
#endif
/* ARGSUSED */
int
sys_setloginclass(struct thread *td, struct setloginclass_args *uap)
{
struct proc *p = td->td_proc;
int error;
char lcname[MAXLOGNAME];
struct loginclass *newlc;
struct ucred *newcred, *oldcred;
error = priv_check(td, PRIV_PROC_SETLOGINCLASS);
if (error != 0)
return (error);
error = copyinstr(uap->namebuf, lcname, sizeof(lcname), NULL);
if (error != 0)
return (error);
newlc = loginclass_find(lcname);
if (newlc == NULL)
return (EINVAL);
newcred = crget();
PROC_LOCK(p);
oldcred = crcopysafe(p, newcred);
newcred->cr_loginclass = newlc;
proc_set_cred(p, newcred);
#ifdef RACCT
racct_proc_ucred_changed(p, oldcred, newcred);
crhold(newcred);
#endif
PROC_UNLOCK(p);
#ifdef RCTL
rctl_proc_ucred_changed(p, newcred);
crfree(newcred);
#endif
loginclass_free(oldcred->cr_loginclass);
crfree(oldcred);
return (0);
}
void
loginclass_racct_foreach(void (*callback)(struct racct *racct,
void *arg2, void *arg3), void (*pre)(void), void (*post)(void),
void *arg2, void *arg3)
{
struct loginclass *lc;
rw_rlock(&loginclasses_lock);
if (pre != NULL)
(pre)();
LIST_FOREACH(lc, &loginclasses, lc_next)
(callback)(lc->lc_racct, arg2, arg3);
if (post != NULL)
(post)();
rw_runlock(&loginclasses_lock);
}
