/*-
* 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/mutex.h>
#include <sys/types.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/racct.h>
#include <sys/refcount.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 mtx loginclasses_lock;
static void lc_init(void);
SYSINIT(loginclass, SI_SUB_CPU, SI_ORDER_FIRST, lc_init, NULL);
void
loginclass_hold(struct loginclass *lc)
{
refcount_acquire(&lc->lc_refcount);
}
void
loginclass_free(struct loginclass *lc)
{
int old;
old = lc->lc_refcount;
if (old > 1 && atomic_cmpset_int(&lc->lc_refcount, old, old - 1))
return;
mtx_lock(&loginclasses_lock);
if (refcount_release(&lc->lc_refcount)) {
racct_destroy(&lc->lc_racct);
LIST_REMOVE(lc, lc_next);
mtx_unlock(&loginclasses_lock);
free(lc, M_LOGINCLASS);
return;
}
mtx_unlock(&loginclasses_lock);
}
/*
* 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, *newlc;
if (name[0] == '\0' || strlen(name) >= MAXLOGNAME)
return (NULL);
newlc = malloc(sizeof(*newlc), M_LOGINCLASS, M_ZERO | M_WAITOK);
racct_create(&newlc->lc_racct);
mtx_lock(&loginclasses_lock);
LIST_FOREACH(lc, &loginclasses, lc_next) {
if (strcmp(name, lc->lc_name) != 0)
continue;
/* Found loginclass with a matching name? */
loginclass_hold(lc);
mtx_unlock(&loginclasses_lock);
racct_destroy(&newlc->lc_racct);
free(newlc, M_LOGINCLASS);
return (lc);
}
/* Add new loginclass. */
strcpy(newlc->lc_name, name);
refcount_init(&newlc->lc_refcount, 1);
LIST_INSERT_HEAD(&loginclasses, newlc, lc_next);
mtx_unlock(&loginclasses_lock);
return (newlc);
}
/*
* Get login class name.
*/
#ifndef _SYS_SYSPROTO_H_
struct getloginclass_args {
char *namebuf;
size_t namelen;
};
#endif
/* ARGSUSED */
int
getloginclass(struct thread *td, struct getloginclass_args *uap)
{
int error = 0;
size_t lcnamelen;
struct proc *p;
struct loginclass *lc;
p = td->td_proc;
PROC_LOCK(p);
lc = p->p_ucred->cr_loginclass;
loginclass_hold(lc);
PROC_UNLOCK(p);
lcnamelen = strlen(lc->lc_name) + 1;
if (lcnamelen > uap->namelen)
error = ERANGE;
if (error == 0)
error = copyout(lc->lc_name, uap->namebuf, lcnamelen);
loginclass_free(lc);
return (error);
}
/*
* Set login class name.
*/
#ifndef _SYS_SYSPROTO_H_
struct setloginclass_args {
const char *namebuf;
};
#endif
/* ARGSUSED */
int
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;
p->p_ucred = newcred;
PROC_UNLOCK(p);
#ifdef RACCT
racct_proc_ucred_changed(p, oldcred, 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 *arg2, void *arg3)
{
struct loginclass *lc;
mtx_lock(&loginclasses_lock);
LIST_FOREACH(lc, &loginclasses, lc_next)
(callback)(lc->lc_racct, arg2, arg3);
mtx_unlock(&loginclasses_lock);
}
static void
lc_init(void)
{
mtx_init(&loginclasses_lock, "loginclasses lock", NULL, MTX_DEF);
}
