1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate /*
28*0Sstevel@tonic-gate  * 	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T
29*0Sstevel@tonic-gate  */
30*0Sstevel@tonic-gate 
31*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
32*0Sstevel@tonic-gate 
33*0Sstevel@tonic-gate #include <sys/param.h>
34*0Sstevel@tonic-gate #include <sys/types.h>
35*0Sstevel@tonic-gate #include <sys/sysmacros.h>
36*0Sstevel@tonic-gate #include <sys/systm.h>
37*0Sstevel@tonic-gate #include <sys/tuneable.h>
38*0Sstevel@tonic-gate #include <sys/cred_impl.h>
39*0Sstevel@tonic-gate #include <sys/errno.h>
40*0Sstevel@tonic-gate #include <sys/proc.h>
41*0Sstevel@tonic-gate #include <sys/signal.h>
42*0Sstevel@tonic-gate #include <sys/debug.h>
43*0Sstevel@tonic-gate #include <sys/policy.h>
44*0Sstevel@tonic-gate #include <sys/zone.h>
45*0Sstevel@tonic-gate 
46*0Sstevel@tonic-gate int
47*0Sstevel@tonic-gate setuid(uid_t uid)
48*0Sstevel@tonic-gate {
49*0Sstevel@tonic-gate 	register proc_t *p;
50*0Sstevel@tonic-gate 	int error;
51*0Sstevel@tonic-gate 	int do_nocd = 0;
52*0Sstevel@tonic-gate 	int uidchge = 0;
53*0Sstevel@tonic-gate 	cred_t	*cr, *newcr;
54*0Sstevel@tonic-gate 	uid_t oldruid = uid;
55*0Sstevel@tonic-gate 	zoneid_t zoneid = getzoneid();
56*0Sstevel@tonic-gate 
57*0Sstevel@tonic-gate 	if (uid < 0 || uid > MAXUID)
58*0Sstevel@tonic-gate 		return (set_errno(EINVAL));
59*0Sstevel@tonic-gate 
60*0Sstevel@tonic-gate 	/*
61*0Sstevel@tonic-gate 	 * Need to pre-allocate the new cred structure before grabbing
62*0Sstevel@tonic-gate 	 * the p_crlock mutex.
63*0Sstevel@tonic-gate 	 */
64*0Sstevel@tonic-gate 	newcr = cralloc();
65*0Sstevel@tonic-gate 
66*0Sstevel@tonic-gate 	p = ttoproc(curthread);
67*0Sstevel@tonic-gate 
68*0Sstevel@tonic-gate retry:
69*0Sstevel@tonic-gate 	mutex_enter(&p->p_crlock);
70*0Sstevel@tonic-gate 	cr = p->p_cred;
71*0Sstevel@tonic-gate 
72*0Sstevel@tonic-gate 	if ((uid == cr->cr_ruid || uid == cr->cr_suid) &&
73*0Sstevel@tonic-gate 	    secpolicy_allow_setid(cr, uid, B_TRUE) != 0) {
74*0Sstevel@tonic-gate 		error = 0;
75*0Sstevel@tonic-gate 		crcopy_to(cr, newcr);
76*0Sstevel@tonic-gate 		p->p_cred = newcr;
77*0Sstevel@tonic-gate 		newcr->cr_uid = uid;
78*0Sstevel@tonic-gate 	} else if ((error = secpolicy_allow_setid(cr, uid, B_FALSE)) == 0) {
79*0Sstevel@tonic-gate 		if (!uidchge && uid != cr->cr_ruid) {
80*0Sstevel@tonic-gate 			/*
81*0Sstevel@tonic-gate 			 * The ruid of the process is going to change. In order
82*0Sstevel@tonic-gate 			 * to avoid a race condition involving the
83*0Sstevel@tonic-gate 			 * process-count associated with the newly given ruid,
84*0Sstevel@tonic-gate 			 * we increment the count before assigning the
85*0Sstevel@tonic-gate 			 * credential to the process.
86*0Sstevel@tonic-gate 			 * To do that, we'll have to take pidlock, so we first
87*0Sstevel@tonic-gate 			 * release p_crlock.
88*0Sstevel@tonic-gate 			 */
89*0Sstevel@tonic-gate 			mutex_exit(&p->p_crlock);
90*0Sstevel@tonic-gate 			uidchge = 1;
91*0Sstevel@tonic-gate 			mutex_enter(&pidlock);
92*0Sstevel@tonic-gate 			upcount_inc(uid, zoneid);
93*0Sstevel@tonic-gate 			mutex_exit(&pidlock);
94*0Sstevel@tonic-gate 			/*
95*0Sstevel@tonic-gate 			 * As we released p_crlock we can't rely on the cr
96*0Sstevel@tonic-gate 			 * we read. So retry the whole thing.
97*0Sstevel@tonic-gate 			 */
98*0Sstevel@tonic-gate 			goto retry;
99*0Sstevel@tonic-gate 		}
100*0Sstevel@tonic-gate 		/*
101*0Sstevel@tonic-gate 		 * A privileged process that gives up its privilege
102*0Sstevel@tonic-gate 		 * must be marked to produce no core dump.
103*0Sstevel@tonic-gate 		 */
104*0Sstevel@tonic-gate 		if (cr->cr_uid != uid ||
105*0Sstevel@tonic-gate 		    cr->cr_ruid != uid ||
106*0Sstevel@tonic-gate 		    cr->cr_suid != uid)
107*0Sstevel@tonic-gate 			do_nocd = 1;
108*0Sstevel@tonic-gate 		oldruid = cr->cr_ruid;
109*0Sstevel@tonic-gate 		crcopy_to(cr, newcr);
110*0Sstevel@tonic-gate 		p->p_cred = newcr;
111*0Sstevel@tonic-gate 		newcr->cr_ruid = uid;
112*0Sstevel@tonic-gate 		newcr->cr_suid = uid;
113*0Sstevel@tonic-gate 		newcr->cr_uid = uid;
114*0Sstevel@tonic-gate 		ASSERT(uid != oldruid ? uidchge : 1);
115*0Sstevel@tonic-gate 	} else
116*0Sstevel@tonic-gate 		crfree(newcr);
117*0Sstevel@tonic-gate 
118*0Sstevel@tonic-gate 	mutex_exit(&p->p_crlock);
119*0Sstevel@tonic-gate 
120*0Sstevel@tonic-gate 	/*
121*0Sstevel@tonic-gate 	 * We decrement the number of processes associated with the oldruid
122*0Sstevel@tonic-gate 	 * to match the increment above, even if the ruid of the process
123*0Sstevel@tonic-gate 	 * did not change or an error occurred (oldruid == uid).
124*0Sstevel@tonic-gate 	 */
125*0Sstevel@tonic-gate 	if (uidchge) {
126*0Sstevel@tonic-gate 		mutex_enter(&pidlock);
127*0Sstevel@tonic-gate 		upcount_dec(oldruid, zoneid);
128*0Sstevel@tonic-gate 		mutex_exit(&pidlock);
129*0Sstevel@tonic-gate 	}
130*0Sstevel@tonic-gate 
131*0Sstevel@tonic-gate 	if (error == 0) {
132*0Sstevel@tonic-gate 		if (do_nocd) {
133*0Sstevel@tonic-gate 			mutex_enter(&p->p_lock);
134*0Sstevel@tonic-gate 			p->p_flag |= SNOCD;
135*0Sstevel@tonic-gate 			mutex_exit(&p->p_lock);
136*0Sstevel@tonic-gate 		}
137*0Sstevel@tonic-gate 		crset(p, newcr);	/* broadcast to process threads */
138*0Sstevel@tonic-gate 		return (0);
139*0Sstevel@tonic-gate 	}
140*0Sstevel@tonic-gate 	return (set_errno(error));
141*0Sstevel@tonic-gate }
142*0Sstevel@tonic-gate 
143*0Sstevel@tonic-gate int64_t
144*0Sstevel@tonic-gate getuid(void)
145*0Sstevel@tonic-gate {
146*0Sstevel@tonic-gate 	rval_t	r;
147*0Sstevel@tonic-gate 	cred_t *cr;
148*0Sstevel@tonic-gate 
149*0Sstevel@tonic-gate 	cr = curthread->t_cred;
150*0Sstevel@tonic-gate 	r.r_val1 = cr->cr_ruid;
151*0Sstevel@tonic-gate 	r.r_val2 = cr->cr_uid;
152*0Sstevel@tonic-gate 	return (r.r_vals);
153*0Sstevel@tonic-gate }
154*0Sstevel@tonic-gate 
155*0Sstevel@tonic-gate int
156*0Sstevel@tonic-gate seteuid(uid_t uid)
157*0Sstevel@tonic-gate {
158*0Sstevel@tonic-gate 	register proc_t *p;
159*0Sstevel@tonic-gate 	int error = EPERM;
160*0Sstevel@tonic-gate 	int do_nocd = 0;
161*0Sstevel@tonic-gate 	cred_t	*cr, *newcr;
162*0Sstevel@tonic-gate 
163*0Sstevel@tonic-gate 	if (uid < 0 || uid > MAXUID)
164*0Sstevel@tonic-gate 		return (set_errno(EINVAL));
165*0Sstevel@tonic-gate 
166*0Sstevel@tonic-gate 	/*
167*0Sstevel@tonic-gate 	 * Need to pre-allocate the new cred structure before grabbing
168*0Sstevel@tonic-gate 	 * the p_crlock mutex.
169*0Sstevel@tonic-gate 	 */
170*0Sstevel@tonic-gate 	newcr = cralloc();
171*0Sstevel@tonic-gate 	p = ttoproc(curthread);
172*0Sstevel@tonic-gate 	mutex_enter(&p->p_crlock);
173*0Sstevel@tonic-gate 	cr = p->p_cred;
174*0Sstevel@tonic-gate 
175*0Sstevel@tonic-gate 	if (uid == cr->cr_ruid || uid == cr->cr_uid || uid == cr->cr_suid ||
176*0Sstevel@tonic-gate 	    (error = secpolicy_allow_setid(cr, uid, B_FALSE)) == 0) {
177*0Sstevel@tonic-gate 		/*
178*0Sstevel@tonic-gate 		 * A privileged process that makes itself look like a
179*0Sstevel@tonic-gate 		 * set-uid process must be marked to produce no core dump,
180*0Sstevel@tonic-gate 		 * if the effective uid did changed.
181*0Sstevel@tonic-gate 		 */
182*0Sstevel@tonic-gate 		if (cr->cr_uid != uid && error == 0)
183*0Sstevel@tonic-gate 			do_nocd = 1;
184*0Sstevel@tonic-gate 		error = 0;
185*0Sstevel@tonic-gate 		crcopy_to(cr, newcr);
186*0Sstevel@tonic-gate 		p->p_cred = newcr;
187*0Sstevel@tonic-gate 		newcr->cr_uid = uid;
188*0Sstevel@tonic-gate 	} else
189*0Sstevel@tonic-gate 		crfree(newcr);
190*0Sstevel@tonic-gate 
191*0Sstevel@tonic-gate 	mutex_exit(&p->p_crlock);
192*0Sstevel@tonic-gate 
193*0Sstevel@tonic-gate 	if (error == 0) {
194*0Sstevel@tonic-gate 		if (do_nocd) {
195*0Sstevel@tonic-gate 			mutex_enter(&p->p_lock);
196*0Sstevel@tonic-gate 			p->p_flag |= SNOCD;
197*0Sstevel@tonic-gate 			mutex_exit(&p->p_lock);
198*0Sstevel@tonic-gate 		}
199*0Sstevel@tonic-gate 		crset(p, newcr);	/* broadcast to process threads */
200*0Sstevel@tonic-gate 		return (0);
201*0Sstevel@tonic-gate 	}
202*0Sstevel@tonic-gate 	return (set_errno(error));
203*0Sstevel@tonic-gate }
204*0Sstevel@tonic-gate 
205*0Sstevel@tonic-gate /*
206*0Sstevel@tonic-gate  * Buy-back from SunOS 4.x
207*0Sstevel@tonic-gate  *
208*0Sstevel@tonic-gate  * Like setuid() and seteuid() combined -except- that non-root users
209*0Sstevel@tonic-gate  * can change cr_ruid to cr_uid, and the semantics of cr_suid are
210*0Sstevel@tonic-gate  * subtly different.
211*0Sstevel@tonic-gate  */
212*0Sstevel@tonic-gate int
213*0Sstevel@tonic-gate setreuid(uid_t ruid, uid_t euid)
214*0Sstevel@tonic-gate {
215*0Sstevel@tonic-gate 	proc_t *p;
216*0Sstevel@tonic-gate 	int error = 0;
217*0Sstevel@tonic-gate 	int do_nocd = 0;
218*0Sstevel@tonic-gate 	int uidchge = 0;
219*0Sstevel@tonic-gate 	uid_t oldruid = ruid;
220*0Sstevel@tonic-gate 	cred_t *cr, *newcr;
221*0Sstevel@tonic-gate 	zoneid_t zoneid = getzoneid();
222*0Sstevel@tonic-gate 
223*0Sstevel@tonic-gate 	if ((ruid != -1 && (ruid < 0 || ruid > MAXUID)) ||
224*0Sstevel@tonic-gate 	    (euid != -1 && (euid < 0 || euid > MAXUID)))
225*0Sstevel@tonic-gate 		return (set_errno(EINVAL));
226*0Sstevel@tonic-gate 
227*0Sstevel@tonic-gate 	/*
228*0Sstevel@tonic-gate 	 * Need to pre-allocate the new cred structure before grabbing
229*0Sstevel@tonic-gate 	 * the p_crlock mutex.
230*0Sstevel@tonic-gate 	 */
231*0Sstevel@tonic-gate 	newcr = cralloc();
232*0Sstevel@tonic-gate 
233*0Sstevel@tonic-gate 	p = ttoproc(curthread);
234*0Sstevel@tonic-gate 
235*0Sstevel@tonic-gate retry:
236*0Sstevel@tonic-gate 	mutex_enter(&p->p_crlock);
237*0Sstevel@tonic-gate 	cr = p->p_cred;
238*0Sstevel@tonic-gate 
239*0Sstevel@tonic-gate 	if (ruid != -1 && ruid != cr->cr_ruid && ruid != cr->cr_uid &&
240*0Sstevel@tonic-gate 	    secpolicy_allow_setid(cr, ruid, B_FALSE) != 0) {
241*0Sstevel@tonic-gate 		error = EPERM;
242*0Sstevel@tonic-gate 	} else if (euid != -1 &&
243*0Sstevel@tonic-gate 	    euid != cr->cr_ruid && euid != cr->cr_uid &&
244*0Sstevel@tonic-gate 	    euid != cr->cr_suid && secpolicy_allow_setid(cr, euid, B_FALSE)) {
245*0Sstevel@tonic-gate 		error = EPERM;
246*0Sstevel@tonic-gate 	} else {
247*0Sstevel@tonic-gate 		if (!uidchge && ruid != -1 && cr->cr_ruid != ruid) {
248*0Sstevel@tonic-gate 			/*
249*0Sstevel@tonic-gate 			 * The ruid of the process is going to change. In order
250*0Sstevel@tonic-gate 			 * to avoid a race condition involving the
251*0Sstevel@tonic-gate 			 * process-count associated with the newly given ruid,
252*0Sstevel@tonic-gate 			 * we increment the count before assigning the
253*0Sstevel@tonic-gate 			 * credential to the process.
254*0Sstevel@tonic-gate 			 * To do that, we'll have to take pidlock, so we first
255*0Sstevel@tonic-gate 			 * release p_crlock.
256*0Sstevel@tonic-gate 			 */
257*0Sstevel@tonic-gate 			mutex_exit(&p->p_crlock);
258*0Sstevel@tonic-gate 			uidchge = 1;
259*0Sstevel@tonic-gate 			mutex_enter(&pidlock);
260*0Sstevel@tonic-gate 			upcount_inc(ruid, zoneid);
261*0Sstevel@tonic-gate 			mutex_exit(&pidlock);
262*0Sstevel@tonic-gate 			/*
263*0Sstevel@tonic-gate 			 * As we released p_crlock we can't rely on the cr
264*0Sstevel@tonic-gate 			 * we read. So retry the whole thing.
265*0Sstevel@tonic-gate 			 */
266*0Sstevel@tonic-gate 			goto retry;
267*0Sstevel@tonic-gate 		}
268*0Sstevel@tonic-gate 		crhold(cr);
269*0Sstevel@tonic-gate 		crcopy_to(cr, newcr);
270*0Sstevel@tonic-gate 		p->p_cred = newcr;
271*0Sstevel@tonic-gate 
272*0Sstevel@tonic-gate 		if (euid != -1)
273*0Sstevel@tonic-gate 			newcr->cr_uid = euid;
274*0Sstevel@tonic-gate 		if (ruid != -1) {
275*0Sstevel@tonic-gate 			oldruid = newcr->cr_ruid;
276*0Sstevel@tonic-gate 			newcr->cr_ruid = ruid;
277*0Sstevel@tonic-gate 			ASSERT(ruid != oldruid ? uidchge : 1);
278*0Sstevel@tonic-gate 		}
279*0Sstevel@tonic-gate 		/*
280*0Sstevel@tonic-gate 		 * "If the real uid is being changed, or the effective uid is
281*0Sstevel@tonic-gate 		 * being changed to a value not equal to the real uid, the
282*0Sstevel@tonic-gate 		 * saved uid is set to the new effective uid."
283*0Sstevel@tonic-gate 		 */
284*0Sstevel@tonic-gate 		if (ruid != -1 ||
285*0Sstevel@tonic-gate 		    (euid != -1 && newcr->cr_uid != newcr->cr_ruid))
286*0Sstevel@tonic-gate 			newcr->cr_suid = newcr->cr_uid;
287*0Sstevel@tonic-gate 		/*
288*0Sstevel@tonic-gate 		 * A process that gives up its privilege
289*0Sstevel@tonic-gate 		 * must be marked to produce no core dump.
290*0Sstevel@tonic-gate 		 */
291*0Sstevel@tonic-gate 		if ((cr->cr_uid != newcr->cr_uid ||
292*0Sstevel@tonic-gate 		    cr->cr_ruid != newcr->cr_ruid ||
293*0Sstevel@tonic-gate 		    cr->cr_suid != newcr->cr_suid))
294*0Sstevel@tonic-gate 			do_nocd = 1;
295*0Sstevel@tonic-gate 
296*0Sstevel@tonic-gate 		crfree(cr);
297*0Sstevel@tonic-gate 	}
298*0Sstevel@tonic-gate 	mutex_exit(&p->p_crlock);
299*0Sstevel@tonic-gate 
300*0Sstevel@tonic-gate 	/*
301*0Sstevel@tonic-gate 	 * We decrement the number of processes associated with the oldruid
302*0Sstevel@tonic-gate 	 * to match the increment above, even if the ruid of the process
303*0Sstevel@tonic-gate 	 * did not change or an error occurred (oldruid == uid).
304*0Sstevel@tonic-gate 	 */
305*0Sstevel@tonic-gate 	if (uidchge) {
306*0Sstevel@tonic-gate 		ASSERT(oldruid != -1 && ruid != -1);
307*0Sstevel@tonic-gate 		mutex_enter(&pidlock);
308*0Sstevel@tonic-gate 		upcount_dec(oldruid, zoneid);
309*0Sstevel@tonic-gate 		mutex_exit(&pidlock);
310*0Sstevel@tonic-gate 	}
311*0Sstevel@tonic-gate 
312*0Sstevel@tonic-gate 	if (error == 0) {
313*0Sstevel@tonic-gate 		if (do_nocd) {
314*0Sstevel@tonic-gate 			mutex_enter(&p->p_lock);
315*0Sstevel@tonic-gate 			p->p_flag |= SNOCD;
316*0Sstevel@tonic-gate 			mutex_exit(&p->p_lock);
317*0Sstevel@tonic-gate 		}
318*0Sstevel@tonic-gate 		crset(p, newcr);	/* broadcast to process threads */
319*0Sstevel@tonic-gate 		return (0);
320*0Sstevel@tonic-gate 	}
321*0Sstevel@tonic-gate 	crfree(newcr);
322*0Sstevel@tonic-gate 	return (set_errno(error));
323*0Sstevel@tonic-gate }
324