xref: /illumos-gate/usr/src/uts/common/syscall/groups.c (revision dd4eeefd)
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 2007 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 
53 	/* Perform the cheapest tests before grabbing p_crlock  */
54 	if (n > ngroups_max || n < 0)
55 		return (set_errno(EINVAL));
56 
57 	if (n != 0) {
58 		groups = kmem_alloc(n * sizeof (gid_t), KM_SLEEP);
59 
60 		if (copyin(gidset, groups, n * sizeof (gid_t)) != 0) {
61 			kmem_free(groups, n * sizeof (gid_t));
62 			return (set_errno(EFAULT));
63 		}
64 
65 		for (i = 0; i < n; i++) {
66 			if (!VALID_GID(groups[i])) {
67 				kmem_free(groups, n * sizeof (gid_t));
68 				return (set_errno(EINVAL));
69 			}
70 			if (groups[i] > MAXUID)
71 				scnt++;
72 		}
73 		if (scnt > 0) {
74 			ksl = kcrsid_gidstosids(n, groups);
75 			if (ksl == NULL) {
76 				kmem_free(groups, n * sizeof (gid_t));
77 				return (set_errno(EINVAL));
78 			}
79 		}
80 	}
81 
82 
83 	/*
84 	 * Need to pre-allocate the new cred structure before acquiring
85 	 * the p_crlock mutex.
86 	 */
87 	newcr = cralloc_ksid();
88 	p = ttoproc(curthread);
89 	mutex_enter(&p->p_crlock);
90 	cr = p->p_cred;
91 
92 	if ((error = secpolicy_allow_setid(cr, -1, B_FALSE)) != 0) {
93 		mutex_exit(&p->p_crlock);
94 		if (groups != NULL)
95 			kmem_free(groups, n * sizeof (gid_t));
96 		if (ksl != NULL)
97 			ksidlist_rele(ksl);
98 		crfree(newcr);
99 		return (set_errno(error));
100 	}
101 
102 	crdup_to(cr, newcr);
103 	crsetsidlist(newcr, ksl);
104 
105 	if (n != 0) {
106 		bcopy(groups, newcr->cr_groups, n * sizeof (gid_t));
107 		kmem_free(groups, n * sizeof (gid_t));
108 	}
109 
110 	newcr->cr_ngroups = n;
111 
112 	p->p_cred = newcr;
113 	crhold(newcr);			/* hold for the current thread */
114 	crfree(cr);			/* free the old one */
115 	mutex_exit(&p->p_crlock);
116 
117 	/*
118 	 * Broadcast new cred to process threads (including the current one).
119 	 */
120 	crset(p, newcr);
121 
122 	return (0);
123 }
124 
125 int
126 getgroups(int gidsetsize, gid_t *gidset)
127 {
128 	struct cred *cr;
129 	int n;
130 
131 	cr = curthread->t_cred;
132 	n = (int)cr->cr_ngroups;
133 
134 	if (gidsetsize != 0) {
135 		if (gidsetsize < n)
136 			return (set_errno(EINVAL));
137 		if (copyout(cr->cr_groups, gidset, n * sizeof (gid_t)))
138 			return (set_errno(EFAULT));
139 	}
140 
141 	return (n);
142 }
143