xref: /illumos-gate/usr/src/uts/common/syscall/groups.c (revision bb9b6b3f59b8820022416cea99b49c50fef6e391)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 
28 #pragma ident	"%Z%%M%	%I%	%E% SMI"	/* from SVr4.0 1.78 */
29 
30 #include <sys/param.h>
31 #include <sys/types.h>
32 #include <sys/sysmacros.h>
33 #include <sys/systm.h>
34 #include <sys/cred_impl.h>
35 #include <sys/errno.h>
36 #include <sys/proc.h>
37 #include <sys/debug.h>
38 #include <sys/kmem.h>
39 #include <sys/policy.h>
40 
41 int
42 setgroups(int gidsetsize, gid_t *gidset)
43 {
44 	proc_t	*p;
45 	cred_t	*cr, *newcr;
46 	int	i;
47 	int	n = gidsetsize;
48 	gid_t	*groups = NULL;
49 	int	error;
50 	int	scnt = 0;
51 	ksidlist_t *ksl = NULL;
52 	zone_t	*zone;
53 
54 	/* Perform the cheapest tests before grabbing p_crlock  */
55 	if (n > ngroups_max || n < 0)
56 		return (set_errno(EINVAL));
57 
58 	zone = crgetzone(CRED());
59 	if (n != 0) {
60 		groups = kmem_alloc(n * sizeof (gid_t), KM_SLEEP);
61 
62 		if (copyin(gidset, groups, n * sizeof (gid_t)) != 0) {
63 			kmem_free(groups, n * sizeof (gid_t));
64 			return (set_errno(EFAULT));
65 		}
66 
67 		for (i = 0; i < n; i++) {
68 			if (!VALID_GID(groups[i], zone)) {
69 				kmem_free(groups, n * sizeof (gid_t));
70 				return (set_errno(EINVAL));
71 			}
72 			if (groups[i] > MAXUID)
73 				scnt++;
74 		}
75 		if (scnt > 0) {
76 			ksl = kcrsid_gidstosids(zone, n, groups);
77 			if (ksl == NULL) {
78 				kmem_free(groups, n * sizeof (gid_t));
79 				return (set_errno(EINVAL));
80 			}
81 		}
82 	}
83 
84 
85 	/*
86 	 * Need to pre-allocate the new cred structure before acquiring
87 	 * the p_crlock mutex.
88 	 */
89 	newcr = cralloc_ksid();
90 	p = ttoproc(curthread);
91 	mutex_enter(&p->p_crlock);
92 retry:
93 	cr = p->p_cred;
94 	crhold(cr);
95 	mutex_exit(&p->p_crlock);
96 
97 	if ((error = secpolicy_allow_setid(cr, -1, B_FALSE)) != 0) {
98 		if (groups != NULL)
99 			kmem_free(groups, n * sizeof (gid_t));
100 		if (ksl != NULL)
101 			ksidlist_rele(ksl);
102 		crfree(newcr);
103 		crfree(cr);
104 		return (set_errno(error));
105 	}
106 	mutex_enter(&p->p_crlock);
107 	crfree(cr);
108 	if (cr != p->p_cred)
109 		goto retry;
110 
111 	crdup_to(cr, newcr);
112 	crsetsidlist(newcr, ksl);
113 
114 	if (n != 0) {
115 		bcopy(groups, newcr->cr_groups, n * sizeof (gid_t));
116 		kmem_free(groups, n * sizeof (gid_t));
117 	}
118 
119 	newcr->cr_ngroups = n;
120 
121 	p->p_cred = newcr;
122 	crhold(newcr);			/* hold for the current thread */
123 	crfree(cr);			/* free the old one */
124 	mutex_exit(&p->p_crlock);
125 
126 	/*
127 	 * Broadcast new cred to process threads (including the current one).
128 	 */
129 	crset(p, newcr);
130 
131 	return (0);
132 }
133 
134 int
135 getgroups(int gidsetsize, gid_t *gidset)
136 {
137 	struct cred *cr;
138 	int n;
139 
140 	cr = curthread->t_cred;
141 	n = (int)cr->cr_ngroups;
142 
143 	if (gidsetsize != 0) {
144 		if (gidsetsize < n)
145 			return (set_errno(EINVAL));
146 		if (copyout(cr->cr_groups, gidset, n * sizeof (gid_t)))
147 			return (set_errno(EFAULT));
148 	}
149 
150 	return (n);
151 }
152