xref: /illumos-gate/usr/src/uts/common/syscall/groups.c (revision 4db555a5389470c6f15aa8b50a38ca5d533d0641)
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 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 
28 #include <sys/param.h>
29 #include <sys/types.h>
30 #include <sys/sysmacros.h>
31 #include <sys/systm.h>
32 #include <sys/cred.h>
33 #include <sys/sid.h>
34 #include <sys/errno.h>
35 #include <sys/proc.h>
36 #include <sys/debug.h>
37 #include <sys/kmem.h>
38 #include <sys/policy.h>
39 
40 int
41 setgroups(int gidsetsize, gid_t *gidset)
42 {
43 	proc_t	*p;
44 	cred_t	*cr, *newcr;
45 	int	i;
46 	int	n = gidsetsize;
47 	int	error;
48 	int	scnt = 0;
49 	ksidlist_t *ksl = NULL;
50 	zone_t	*zone;
51 	struct credgrp *grps = 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 	zone = crgetzone(CRED());
58 	if (n != 0) {
59 		const gid_t *groups;
60 
61 		grps = crgrpcopyin(n, gidset);
62 
63 		if (grps == NULL)
64 			return (set_errno(EFAULT));
65 
66 		groups = crgetggroups(grps);
67 
68 		for (i = 0; i < n; i++) {
69 			if (!VALID_GID(groups[i], zone)) {
70 				crgrprele(grps);
71 				return (set_errno(EINVAL));
72 			}
73 			if (groups[i] > MAXUID)
74 				scnt++;
75 		}
76 		if (scnt > 0) {
77 			ksl = kcrsid_gidstosids(zone, n, (gid_t *)groups);
78 			if (ksl == NULL) {
79 				crgrprele(grps);
80 				return (set_errno(EINVAL));
81 			}
82 		}
83 	}
84 
85 
86 	/*
87 	 * Need to pre-allocate the new cred structure before acquiring
88 	 * the p_crlock mutex.
89 	 */
90 	newcr = cralloc_ksid();
91 	p = ttoproc(curthread);
92 	mutex_enter(&p->p_crlock);
93 retry:
94 	cr = p->p_cred;
95 	crhold(cr);
96 	mutex_exit(&p->p_crlock);
97 
98 	if ((error = secpolicy_allow_setid(cr, -1, B_FALSE)) != 0) {
99 		if (grps != NULL)
100 			crgrprele(grps);
101 		if (ksl != NULL)
102 			ksidlist_rele(ksl);
103 		crfree(newcr);
104 		crfree(cr);
105 		return (set_errno(error));
106 	}
107 	mutex_enter(&p->p_crlock);
108 	crfree(cr);
109 	if (cr != p->p_cred)
110 		goto retry;
111 
112 	crdup_to(cr, newcr);
113 	crsetsidlist(newcr, ksl);
114 	crsetcredgrp(newcr, grps);
115 
116 	p->p_cred = newcr;
117 	crhold(newcr);			/* hold for the current thread */
118 	crfree(cr);			/* free the old one */
119 	mutex_exit(&p->p_crlock);
120 
121 	/*
122 	 * Broadcast new cred to process threads (including the current one).
123 	 */
124 	crset(p, newcr);
125 
126 	return (0);
127 }
128 
129 int
130 getgroups(int gidsetsize, gid_t *gidset)
131 {
132 	struct cred *cr;
133 	int n;
134 
135 	cr = curthread->t_cred;
136 	n = crgetngroups(cr);
137 
138 	if (gidsetsize != 0) {
139 		if (gidsetsize < n)
140 			return (set_errno(EINVAL));
141 		if (copyout(crgetgroups(cr), gidset, n * sizeof (gid_t)))
142 			return (set_errno(EFAULT));
143 	}
144 
145 	return (n);
146 }
147