1 /*
2 * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
3 * Copyright (C) 2007 The Regents of the University of California.
4 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
5 * Written by Brian Behlendorf <behlendorf1@llnl.gov>.
6 * UCRL-CODE-235197
7 *
8 * This file is part of the SPL, Solaris Porting Layer.
9 *
10 * The SPL is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2 of the License, or (at your
13 * option) any later version.
14 *
15 * The SPL is distributed in the hope that it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 * for more details.
19 *
20 * You should have received a copy of the GNU General Public License along
21 * with the SPL. If not, see <http://www.gnu.org/licenses/>.
22 *
23 * Solaris Porting Layer (SPL) Credential Implementation.
24 */
25
26 #include <sys/cred.h>
27
28 static int
cr_groups_search(const struct group_info * group_info,kgid_t grp)29 cr_groups_search(const struct group_info *group_info, kgid_t grp)
30 {
31 unsigned int left, right, mid;
32 int cmp;
33
34 if (!group_info)
35 return (0);
36
37 left = 0;
38 right = group_info->ngroups;
39 while (left < right) {
40 mid = (left + right) / 2;
41 cmp = KGID_TO_SGID(grp) -
42 KGID_TO_SGID(GROUP_AT(group_info, mid));
43
44 if (cmp > 0)
45 left = mid + 1;
46 else if (cmp < 0)
47 right = mid;
48 else
49 return (1);
50 }
51 return (0);
52 }
53
54 /* Hold a reference on the credential */
55 void
crhold(cred_t * cr)56 crhold(cred_t *cr)
57 {
58 (void) get_cred((const cred_t *)cr);
59 }
60
61 /* Free a reference on the credential */
62 void
crfree(cred_t * cr)63 crfree(cred_t *cr)
64 {
65 put_cred((const cred_t *)cr);
66 }
67
68 /* Return the number of supplemental groups */
69 int
crgetngroups(const cred_t * cr)70 crgetngroups(const cred_t *cr)
71 {
72 struct group_info *gi;
73 int rc;
74
75 gi = cr->group_info;
76 rc = gi->ngroups;
77 #ifndef HAVE_GROUP_INFO_GID
78 /*
79 * For Linux <= 4.8,
80 * crgetgroups will only returns gi->blocks[0], which contains only
81 * the first NGROUPS_PER_BLOCK groups.
82 */
83 if (rc > NGROUPS_PER_BLOCK) {
84 WARN_ON_ONCE(1);
85 rc = NGROUPS_PER_BLOCK;
86 }
87 #endif
88 return (rc);
89 }
90
91 /*
92 * Return an array of supplemental gids. The returned address is safe
93 * to use as long as the caller has taken a reference with crhold().
94 *
95 * Linux 4.9 API change, group_info changed from 2d array via ->blocks to 1d
96 * array via ->gid.
97 */
98 gid_t *
crgetgroups(const cred_t * cr)99 crgetgroups(const cred_t *cr)
100 {
101 struct group_info *gi;
102 gid_t *gids = NULL;
103
104 gi = cr->group_info;
105 #ifdef HAVE_GROUP_INFO_GID
106 gids = KGIDP_TO_SGIDP(gi->gid);
107 #else
108 if (gi->nblocks > 0)
109 gids = KGIDP_TO_SGIDP(gi->blocks[0]);
110 #endif
111 return (gids);
112 }
113
114 /* Check if the passed gid is available in supplied credential. */
115 int
groupmember(gid_t gid,const cred_t * cr)116 groupmember(gid_t gid, const cred_t *cr)
117 {
118 struct group_info *gi;
119 int rc;
120
121 gi = cr->group_info;
122 rc = cr_groups_search(gi, SGID_TO_KGID(gid));
123
124 return (rc);
125 }
126
127 /* Return the effective user id */
128 uid_t
crgetuid(const cred_t * cr)129 crgetuid(const cred_t *cr)
130 {
131 return (KUID_TO_SUID(cr->fsuid));
132 }
133
134 /* Return the real user id */
135 uid_t
crgetruid(const cred_t * cr)136 crgetruid(const cred_t *cr)
137 {
138 return (KUID_TO_SUID(cr->uid));
139 }
140
141 /* Return the effective group id */
142 gid_t
crgetgid(const cred_t * cr)143 crgetgid(const cred_t *cr)
144 {
145 return (KGID_TO_SGID(cr->fsgid));
146 }
147
148 /* Return the initial user ns or nop_mnt_idmap */
149 zidmap_t *
zfs_get_init_idmap(void)150 zfs_get_init_idmap(void)
151 {
152 #ifdef HAVE_IOPS_CREATE_IDMAP
153 return ((zidmap_t *)&nop_mnt_idmap);
154 #else
155 return ((zidmap_t *)&init_user_ns);
156 #endif
157 }
158
159 EXPORT_SYMBOL(zfs_get_init_idmap);
160 EXPORT_SYMBOL(crhold);
161 EXPORT_SYMBOL(crfree);
162 EXPORT_SYMBOL(crgetuid);
163 EXPORT_SYMBOL(crgetruid);
164 EXPORT_SYMBOL(crgetgid);
165 EXPORT_SYMBOL(crgetngroups);
166 EXPORT_SYMBOL(crgetgroups);
167 EXPORT_SYMBOL(groupmember);
168