xref: /freebsd/sys/kern/kern_loginclass.c (revision 2bfc50bc4fbc3ad7e8bdfeb6b55d72ea55c4f18b) 
1*2bfc50bcSEdward Tomasz Napierala /*-
2*2bfc50bcSEdward Tomasz Napierala  * Copyright (c) 2011 The FreeBSD Foundation
3*2bfc50bcSEdward Tomasz Napierala  * All rights reserved.
4*2bfc50bcSEdward Tomasz Napierala  *
5*2bfc50bcSEdward Tomasz Napierala  * This software was developed by Edward Tomasz Napierala under sponsorship
6*2bfc50bcSEdward Tomasz Napierala  * from the FreeBSD Foundation.
7*2bfc50bcSEdward Tomasz Napierala  *
8*2bfc50bcSEdward Tomasz Napierala  * Redistribution and use in source and binary forms, with or without
9*2bfc50bcSEdward Tomasz Napierala  * modification, are permitted provided that the following conditions
10*2bfc50bcSEdward Tomasz Napierala  * are met:
11*2bfc50bcSEdward Tomasz Napierala  * 1. Redistributions of source code must retain the above copyright
12*2bfc50bcSEdward Tomasz Napierala  *    notice, this list of conditions and the following disclaimer.
13*2bfc50bcSEdward Tomasz Napierala  * 2. Redistributions in binary form must reproduce the above copyright
14*2bfc50bcSEdward Tomasz Napierala  *    notice, this list of conditions and the following disclaimer in the
15*2bfc50bcSEdward Tomasz Napierala  *    documentation and/or other materials provided with the distribution.
16*2bfc50bcSEdward Tomasz Napierala  *
17*2bfc50bcSEdward Tomasz Napierala  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18*2bfc50bcSEdward Tomasz Napierala  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19*2bfc50bcSEdward Tomasz Napierala  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20*2bfc50bcSEdward Tomasz Napierala  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21*2bfc50bcSEdward Tomasz Napierala  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22*2bfc50bcSEdward Tomasz Napierala  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23*2bfc50bcSEdward Tomasz Napierala  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24*2bfc50bcSEdward Tomasz Napierala  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25*2bfc50bcSEdward Tomasz Napierala  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26*2bfc50bcSEdward Tomasz Napierala  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27*2bfc50bcSEdward Tomasz Napierala  * SUCH DAMAGE.
28*2bfc50bcSEdward Tomasz Napierala  *
29*2bfc50bcSEdward Tomasz Napierala  * $FreeBSD$
30*2bfc50bcSEdward Tomasz Napierala  */
31*2bfc50bcSEdward Tomasz Napierala 
32*2bfc50bcSEdward Tomasz Napierala /*
33*2bfc50bcSEdward Tomasz Napierala  * Processes may set login class name using setloginclass(2).  This
34*2bfc50bcSEdward Tomasz Napierala  * is usually done through call to setusercontext(3), by programs
35*2bfc50bcSEdward Tomasz Napierala  * such as login(1), based on information from master.passwd(5).  Kernel
36*2bfc50bcSEdward Tomasz Napierala  * uses this information to enforce per-class resource limits.  Current
37*2bfc50bcSEdward Tomasz Napierala  * login class can be determined using id(1).  Login class is inherited
38*2bfc50bcSEdward Tomasz Napierala  * from the parent process during fork(2).  If not set, it defaults
39*2bfc50bcSEdward Tomasz Napierala  * to "default".
40*2bfc50bcSEdward Tomasz Napierala  *
41*2bfc50bcSEdward Tomasz Napierala  * Code in this file implements setloginclass(2) and getloginclass(2)
42*2bfc50bcSEdward Tomasz Napierala  * system calls, and maintains class name storage and retrieval.
43*2bfc50bcSEdward Tomasz Napierala  */
44*2bfc50bcSEdward Tomasz Napierala 
45*2bfc50bcSEdward Tomasz Napierala #include <sys/cdefs.h>
46*2bfc50bcSEdward Tomasz Napierala __FBSDID("$FreeBSD$");
47*2bfc50bcSEdward Tomasz Napierala 
48*2bfc50bcSEdward Tomasz Napierala #include <sys/param.h>
49*2bfc50bcSEdward Tomasz Napierala #include <sys/eventhandler.h>
50*2bfc50bcSEdward Tomasz Napierala #include <sys/kernel.h>
51*2bfc50bcSEdward Tomasz Napierala #include <sys/lock.h>
52*2bfc50bcSEdward Tomasz Napierala #include <sys/loginclass.h>
53*2bfc50bcSEdward Tomasz Napierala #include <sys/malloc.h>
54*2bfc50bcSEdward Tomasz Napierala #include <sys/mutex.h>
55*2bfc50bcSEdward Tomasz Napierala #include <sys/types.h>
56*2bfc50bcSEdward Tomasz Napierala #include <sys/priv.h>
57*2bfc50bcSEdward Tomasz Napierala #include <sys/proc.h>
58*2bfc50bcSEdward Tomasz Napierala #include <sys/queue.h>
59*2bfc50bcSEdward Tomasz Napierala #include <sys/refcount.h>
60*2bfc50bcSEdward Tomasz Napierala #include <sys/sysproto.h>
61*2bfc50bcSEdward Tomasz Napierala #include <sys/systm.h>
62*2bfc50bcSEdward Tomasz Napierala 
63*2bfc50bcSEdward Tomasz Napierala static MALLOC_DEFINE(M_LOGINCLASS, "loginclass", "loginclass structures");
64*2bfc50bcSEdward Tomasz Napierala 
65*2bfc50bcSEdward Tomasz Napierala LIST_HEAD(, loginclass)	loginclasses;
66*2bfc50bcSEdward Tomasz Napierala 
67*2bfc50bcSEdward Tomasz Napierala /*
68*2bfc50bcSEdward Tomasz Napierala  * Lock protecting loginclasses list.
69*2bfc50bcSEdward Tomasz Napierala  */
70*2bfc50bcSEdward Tomasz Napierala static struct mtx loginclasses_lock;
71*2bfc50bcSEdward Tomasz Napierala 
72*2bfc50bcSEdward Tomasz Napierala static void lc_init(void);
73*2bfc50bcSEdward Tomasz Napierala SYSINIT(loginclass, SI_SUB_CPU, SI_ORDER_FIRST, lc_init, NULL);
74*2bfc50bcSEdward Tomasz Napierala 
75*2bfc50bcSEdward Tomasz Napierala void
76*2bfc50bcSEdward Tomasz Napierala loginclass_hold(struct loginclass *lc)
77*2bfc50bcSEdward Tomasz Napierala {
78*2bfc50bcSEdward Tomasz Napierala 
79*2bfc50bcSEdward Tomasz Napierala 	refcount_acquire(&lc->lc_refcount);
80*2bfc50bcSEdward Tomasz Napierala }
81*2bfc50bcSEdward Tomasz Napierala 
82*2bfc50bcSEdward Tomasz Napierala void
83*2bfc50bcSEdward Tomasz Napierala loginclass_free(struct loginclass *lc)
84*2bfc50bcSEdward Tomasz Napierala {
85*2bfc50bcSEdward Tomasz Napierala 	int old;
86*2bfc50bcSEdward Tomasz Napierala 
87*2bfc50bcSEdward Tomasz Napierala 	old = lc->lc_refcount;
88*2bfc50bcSEdward Tomasz Napierala 	if (old > 1 && atomic_cmpset_int(&lc->lc_refcount, old, old - 1))
89*2bfc50bcSEdward Tomasz Napierala 		return;
90*2bfc50bcSEdward Tomasz Napierala 
91*2bfc50bcSEdward Tomasz Napierala 	mtx_lock(&loginclasses_lock);
92*2bfc50bcSEdward Tomasz Napierala 	if (refcount_release(&lc->lc_refcount)) {
93*2bfc50bcSEdward Tomasz Napierala 		LIST_REMOVE(lc, lc_next);
94*2bfc50bcSEdward Tomasz Napierala 		mtx_unlock(&loginclasses_lock);
95*2bfc50bcSEdward Tomasz Napierala 		free(lc, M_LOGINCLASS);
96*2bfc50bcSEdward Tomasz Napierala 
97*2bfc50bcSEdward Tomasz Napierala 		return;
98*2bfc50bcSEdward Tomasz Napierala 	}
99*2bfc50bcSEdward Tomasz Napierala 	mtx_unlock(&loginclasses_lock);
100*2bfc50bcSEdward Tomasz Napierala }
101*2bfc50bcSEdward Tomasz Napierala 
102*2bfc50bcSEdward Tomasz Napierala /*
103*2bfc50bcSEdward Tomasz Napierala  * Return loginclass structure with a corresponding name.  Not
104*2bfc50bcSEdward Tomasz Napierala  * performance critical, as it's used mainly by setloginclass(2),
105*2bfc50bcSEdward Tomasz Napierala  * which happens once per login session.  Caller has to use
106*2bfc50bcSEdward Tomasz Napierala  * loginclass_free() on the returned value when it's no longer
107*2bfc50bcSEdward Tomasz Napierala  * needed.
108*2bfc50bcSEdward Tomasz Napierala  */
109*2bfc50bcSEdward Tomasz Napierala struct loginclass *
110*2bfc50bcSEdward Tomasz Napierala loginclass_find(const char *name)
111*2bfc50bcSEdward Tomasz Napierala {
112*2bfc50bcSEdward Tomasz Napierala 	struct loginclass *lc, *newlc;
113*2bfc50bcSEdward Tomasz Napierala 
114*2bfc50bcSEdward Tomasz Napierala 	if (name[0] == '\0' || strlen(name) >= MAXLOGNAME)
115*2bfc50bcSEdward Tomasz Napierala 		return (NULL);
116*2bfc50bcSEdward Tomasz Napierala 
117*2bfc50bcSEdward Tomasz Napierala 	newlc = malloc(sizeof(*newlc), M_LOGINCLASS, M_ZERO | M_WAITOK);
118*2bfc50bcSEdward Tomasz Napierala 
119*2bfc50bcSEdward Tomasz Napierala 	mtx_lock(&loginclasses_lock);
120*2bfc50bcSEdward Tomasz Napierala 	LIST_FOREACH(lc, &loginclasses, lc_next) {
121*2bfc50bcSEdward Tomasz Napierala 		if (strcmp(name, lc->lc_name) != 0)
122*2bfc50bcSEdward Tomasz Napierala 			continue;
123*2bfc50bcSEdward Tomasz Napierala 
124*2bfc50bcSEdward Tomasz Napierala 		/* Found loginclass with a matching name? */
125*2bfc50bcSEdward Tomasz Napierala 		loginclass_hold(lc);
126*2bfc50bcSEdward Tomasz Napierala 		mtx_unlock(&loginclasses_lock);
127*2bfc50bcSEdward Tomasz Napierala 		free(newlc, M_LOGINCLASS);
128*2bfc50bcSEdward Tomasz Napierala 		return (lc);
129*2bfc50bcSEdward Tomasz Napierala 	}
130*2bfc50bcSEdward Tomasz Napierala 
131*2bfc50bcSEdward Tomasz Napierala 	/* Add new loginclass. */
132*2bfc50bcSEdward Tomasz Napierala 	strcpy(newlc->lc_name, name);
133*2bfc50bcSEdward Tomasz Napierala 	refcount_init(&newlc->lc_refcount, 1);
134*2bfc50bcSEdward Tomasz Napierala 	LIST_INSERT_HEAD(&loginclasses, newlc, lc_next);
135*2bfc50bcSEdward Tomasz Napierala 	mtx_unlock(&loginclasses_lock);
136*2bfc50bcSEdward Tomasz Napierala 
137*2bfc50bcSEdward Tomasz Napierala 	return (newlc);
138*2bfc50bcSEdward Tomasz Napierala }
139*2bfc50bcSEdward Tomasz Napierala 
140*2bfc50bcSEdward Tomasz Napierala /*
141*2bfc50bcSEdward Tomasz Napierala  * Get login class name.
142*2bfc50bcSEdward Tomasz Napierala  */
143*2bfc50bcSEdward Tomasz Napierala #ifndef _SYS_SYSPROTO_H_
144*2bfc50bcSEdward Tomasz Napierala struct getloginclass_args {
145*2bfc50bcSEdward Tomasz Napierala 	char	*namebuf;
146*2bfc50bcSEdward Tomasz Napierala 	size_t	namelen;
147*2bfc50bcSEdward Tomasz Napierala };
148*2bfc50bcSEdward Tomasz Napierala #endif
149*2bfc50bcSEdward Tomasz Napierala /* ARGSUSED */
150*2bfc50bcSEdward Tomasz Napierala int
151*2bfc50bcSEdward Tomasz Napierala getloginclass(struct thread *td, struct getloginclass_args *uap)
152*2bfc50bcSEdward Tomasz Napierala {
153*2bfc50bcSEdward Tomasz Napierala 	int error = 0;
154*2bfc50bcSEdward Tomasz Napierala 	size_t lcnamelen;
155*2bfc50bcSEdward Tomasz Napierala 	struct proc *p;
156*2bfc50bcSEdward Tomasz Napierala 	struct loginclass *lc;
157*2bfc50bcSEdward Tomasz Napierala 
158*2bfc50bcSEdward Tomasz Napierala 	p = td->td_proc;
159*2bfc50bcSEdward Tomasz Napierala 	PROC_LOCK(p);
160*2bfc50bcSEdward Tomasz Napierala 	lc = p->p_ucred->cr_loginclass;
161*2bfc50bcSEdward Tomasz Napierala 	loginclass_hold(lc);
162*2bfc50bcSEdward Tomasz Napierala 	PROC_UNLOCK(p);
163*2bfc50bcSEdward Tomasz Napierala 
164*2bfc50bcSEdward Tomasz Napierala 	lcnamelen = strlen(lc->lc_name) + 1;
165*2bfc50bcSEdward Tomasz Napierala 	if (lcnamelen > uap->namelen)
166*2bfc50bcSEdward Tomasz Napierala 		error = ERANGE;
167*2bfc50bcSEdward Tomasz Napierala 	if (error == 0)
168*2bfc50bcSEdward Tomasz Napierala 		error = copyout(lc->lc_name, uap->namebuf, lcnamelen);
169*2bfc50bcSEdward Tomasz Napierala 	loginclass_free(lc);
170*2bfc50bcSEdward Tomasz Napierala 	return (error);
171*2bfc50bcSEdward Tomasz Napierala }
172*2bfc50bcSEdward Tomasz Napierala 
173*2bfc50bcSEdward Tomasz Napierala /*
174*2bfc50bcSEdward Tomasz Napierala  * Set login class name.
175*2bfc50bcSEdward Tomasz Napierala  */
176*2bfc50bcSEdward Tomasz Napierala #ifndef _SYS_SYSPROTO_H_
177*2bfc50bcSEdward Tomasz Napierala struct setloginclass_args {
178*2bfc50bcSEdward Tomasz Napierala 	const char	*namebuf;
179*2bfc50bcSEdward Tomasz Napierala };
180*2bfc50bcSEdward Tomasz Napierala #endif
181*2bfc50bcSEdward Tomasz Napierala /* ARGSUSED */
182*2bfc50bcSEdward Tomasz Napierala int
183*2bfc50bcSEdward Tomasz Napierala setloginclass(struct thread *td, struct setloginclass_args *uap)
184*2bfc50bcSEdward Tomasz Napierala {
185*2bfc50bcSEdward Tomasz Napierala 	struct proc *p = td->td_proc;
186*2bfc50bcSEdward Tomasz Napierala 	int error;
187*2bfc50bcSEdward Tomasz Napierala 	char lcname[MAXLOGNAME];
188*2bfc50bcSEdward Tomasz Napierala 	struct loginclass *newlc;
189*2bfc50bcSEdward Tomasz Napierala 	struct ucred *newcred, *oldcred;
190*2bfc50bcSEdward Tomasz Napierala 
191*2bfc50bcSEdward Tomasz Napierala 	error = priv_check(td, PRIV_PROC_SETLOGINCLASS);
192*2bfc50bcSEdward Tomasz Napierala 	if (error != 0)
193*2bfc50bcSEdward Tomasz Napierala 		return (error);
194*2bfc50bcSEdward Tomasz Napierala 	error = copyinstr(uap->namebuf, lcname, sizeof(lcname), NULL);
195*2bfc50bcSEdward Tomasz Napierala 	if (error != 0)
196*2bfc50bcSEdward Tomasz Napierala 		return (error);
197*2bfc50bcSEdward Tomasz Napierala 
198*2bfc50bcSEdward Tomasz Napierala 	newlc = loginclass_find(lcname);
199*2bfc50bcSEdward Tomasz Napierala 	if (newlc == NULL)
200*2bfc50bcSEdward Tomasz Napierala 		return (EINVAL);
201*2bfc50bcSEdward Tomasz Napierala 	newcred = crget();
202*2bfc50bcSEdward Tomasz Napierala 
203*2bfc50bcSEdward Tomasz Napierala 	PROC_LOCK(p);
204*2bfc50bcSEdward Tomasz Napierala 	oldcred = crcopysafe(p, newcred);
205*2bfc50bcSEdward Tomasz Napierala 	newcred->cr_loginclass = newlc;
206*2bfc50bcSEdward Tomasz Napierala 	p->p_ucred = newcred;
207*2bfc50bcSEdward Tomasz Napierala 	PROC_UNLOCK(p);
208*2bfc50bcSEdward Tomasz Napierala 
209*2bfc50bcSEdward Tomasz Napierala 	loginclass_free(oldcred->cr_loginclass);
210*2bfc50bcSEdward Tomasz Napierala 	crfree(oldcred);
211*2bfc50bcSEdward Tomasz Napierala 
212*2bfc50bcSEdward Tomasz Napierala 	return (0);
213*2bfc50bcSEdward Tomasz Napierala }
214*2bfc50bcSEdward Tomasz Napierala 
215*2bfc50bcSEdward Tomasz Napierala static void
216*2bfc50bcSEdward Tomasz Napierala lc_init(void)
217*2bfc50bcSEdward Tomasz Napierala {
218*2bfc50bcSEdward Tomasz Napierala 
219*2bfc50bcSEdward Tomasz Napierala 	mtx_init(&loginclasses_lock, "loginclasses lock", NULL, MTX_DEF);
220*2bfc50bcSEdward Tomasz Napierala }
221