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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2008, Christoph Hellwig
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_shared.h"
8#include "xfs_format.h"
9#include "xfs_log_format.h"
10#include "xfs_trans_resv.h"
11#include "xfs_mount.h"
12#include "xfs_inode.h"
13#include "xfs_attr.h"
14#include "xfs_trace.h"
15#include "xfs_error.h"
16#include "xfs_acl.h"
17#include "xfs_da_format.h"
18#include "xfs_da_btree.h"
19
20#include <linux/posix_acl_xattr.h>
21
22/*
23 * Locking scheme:
24 * - all ACL updates are protected by inode->i_mutex, which is taken before
25 * calling into this file.
26 */
27
28STATIC struct posix_acl *
29xfs_acl_from_disk(
30 struct xfs_mount *mp,
31 const struct xfs_acl *aclp,
32 int len,
33 int max_entries)
34{
35 struct posix_acl_entry *acl_e;
36 struct posix_acl *acl;
37 const struct xfs_acl_entry *ace;
38 unsigned int count, i;
39
40 if (len < sizeof(*aclp)) {
41 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
42 len);
43 return ERR_PTR(-EFSCORRUPTED);
44 }
45
46 count = be32_to_cpu(aclp->acl_cnt);
47 if (count > max_entries || XFS_ACL_SIZE(count) != len) {
48 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
49 len);
50 return ERR_PTR(-EFSCORRUPTED);
51 }
52
53 acl = posix_acl_alloc(count, GFP_KERNEL);
54 if (!acl)
55 return ERR_PTR(-ENOMEM);
56
57 for (i = 0; i < count; i++) {
58 acl_e = &acl->a_entries[i];
59 ace = &aclp->acl_entry[i];
60
61 /*
62 * The tag is 32 bits on disk and 16 bits in core.
63 *
64 * Because every access to it goes through the core
65 * format first this is not a problem.
66 */
67 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
68 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
69
70 switch (acl_e->e_tag) {
71 case ACL_USER:
72 acl_e->e_uid = make_kuid(&init_user_ns,
73 be32_to_cpu(ace->ae_id));
74 break;
75 case ACL_GROUP:
76 acl_e->e_gid = make_kgid(&init_user_ns,
77 be32_to_cpu(ace->ae_id));
78 break;
79 case ACL_USER_OBJ:
80 case ACL_GROUP_OBJ:
81 case ACL_MASK:
82 case ACL_OTHER:
83 break;
84 default:
85 goto fail;
86 }
87 }
88 return acl;
89
90fail:
91 posix_acl_release(acl);
92 return ERR_PTR(-EINVAL);
93}
94
95STATIC void
96xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
97{
98 const struct posix_acl_entry *acl_e;
99 struct xfs_acl_entry *ace;
100 int i;
101
102 aclp->acl_cnt = cpu_to_be32(acl->a_count);
103 for (i = 0; i < acl->a_count; i++) {
104 ace = &aclp->acl_entry[i];
105 acl_e = &acl->a_entries[i];
106
107 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
108 switch (acl_e->e_tag) {
109 case ACL_USER:
110 ace->ae_id = cpu_to_be32(
111 from_kuid(&init_user_ns, acl_e->e_uid));
112 break;
113 case ACL_GROUP:
114 ace->ae_id = cpu_to_be32(
115 from_kgid(&init_user_ns, acl_e->e_gid));
116 break;
117 default:
118 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
119 break;
120 }
121
122 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
123 }
124}
125
126struct posix_acl *
127xfs_get_acl(struct inode *inode, int type)
128{
129 struct xfs_inode *ip = XFS_I(inode);
130 struct xfs_mount *mp = ip->i_mount;
131 struct posix_acl *acl = NULL;
132 struct xfs_da_args args = {
133 .dp = ip,
134 .attr_filter = XFS_ATTR_ROOT,
135 .valuelen = XFS_ACL_MAX_SIZE(mp),
136 };
137 int error;
138
139 trace_xfs_get_acl(ip);
140
141 switch (type) {
142 case ACL_TYPE_ACCESS:
143 args.name = SGI_ACL_FILE;
144 break;
145 case ACL_TYPE_DEFAULT:
146 args.name = SGI_ACL_DEFAULT;
147 break;
148 default:
149 BUG();
150 }
151 args.namelen = strlen(args.name);
152
153 /*
154 * If the attribute doesn't exist make sure we have a negative cache
155 * entry, for any other error assume it is transient.
156 */
157 error = xfs_attr_get(&args);
158 if (!error) {
159 acl = xfs_acl_from_disk(mp, args.value, args.valuelen,
160 XFS_ACL_MAX_ENTRIES(mp));
161 } else if (error != -ENOATTR) {
162 acl = ERR_PTR(error);
163 }
164
165 kmem_free(args.value);
166 return acl;
167}
168
169int
170__xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
171{
172 struct xfs_inode *ip = XFS_I(inode);
173 struct xfs_da_args args = {
174 .dp = ip,
175 .attr_filter = XFS_ATTR_ROOT,
176 };
177 int error;
178
179 switch (type) {
180 case ACL_TYPE_ACCESS:
181 args.name = SGI_ACL_FILE;
182 break;
183 case ACL_TYPE_DEFAULT:
184 if (!S_ISDIR(inode->i_mode))
185 return acl ? -EACCES : 0;
186 args.name = SGI_ACL_DEFAULT;
187 break;
188 default:
189 return -EINVAL;
190 }
191 args.namelen = strlen(args.name);
192
193 if (acl) {
194 args.valuelen = XFS_ACL_SIZE(acl->a_count);
195 args.value = kmem_zalloc_large(args.valuelen, 0);
196 if (!args.value)
197 return -ENOMEM;
198 xfs_acl_to_disk(args.value, acl);
199 }
200
201 error = xfs_attr_set(&args);
202 kmem_free(args.value);
203
204 /*
205 * If the attribute didn't exist to start with that's fine.
206 */
207 if (!acl && error == -ENOATTR)
208 error = 0;
209 if (!error)
210 set_cached_acl(inode, type, acl);
211 return error;
212}
213
214static int
215xfs_set_mode(struct inode *inode, umode_t mode)
216{
217 int error = 0;
218
219 if (mode != inode->i_mode) {
220 struct iattr iattr;
221
222 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
223 iattr.ia_mode = mode;
224 iattr.ia_ctime = current_time(inode);
225
226 error = xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
227 }
228
229 return error;
230}
231
232int
233xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
234{
235 umode_t mode;
236 bool set_mode = false;
237 int error = 0;
238
239 if (!acl)
240 goto set_acl;
241
242 error = -E2BIG;
243 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
244 return error;
245
246 if (type == ACL_TYPE_ACCESS) {
247 error = posix_acl_update_mode(inode, &mode, &acl);
248 if (error)
249 return error;
250 set_mode = true;
251 }
252
253 set_acl:
254 error = __xfs_set_acl(inode, acl, type);
255 if (error)
256 return error;
257
258 /*
259 * We set the mode after successfully updating the ACL xattr because the
260 * xattr update can fail at ENOSPC and we don't want to change the mode
261 * if the ACL update hasn't been applied.
262 */
263 if (set_mode)
264 error = xfs_set_mode(inode, mode);
265
266 return error;
267}
268
269/*
270 * Invalidate any cached ACLs if the user has bypassed the ACL interface.
271 * We don't validate the content whatsoever so it is caller responsibility to
272 * provide data in valid format and ensure i_mode is consistent.
273 */
274void
275xfs_forget_acl(
276 struct inode *inode,
277 const char *name)
278{
279 if (!strcmp(name, SGI_ACL_FILE))
280 forget_cached_acl(inode, ACL_TYPE_ACCESS);
281 else if (!strcmp(name, SGI_ACL_DEFAULT))
282 forget_cached_acl(inode, ACL_TYPE_DEFAULT);
283}
1/*
2 * Copyright (c) 2008, Christoph Hellwig
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#include "xfs.h"
19#include "xfs_format.h"
20#include "xfs_log_format.h"
21#include "xfs_trans_resv.h"
22#include "xfs_mount.h"
23#include "xfs_inode.h"
24#include "xfs_acl.h"
25#include "xfs_attr.h"
26#include "xfs_trace.h"
27#include <linux/slab.h>
28#include <linux/xattr.h>
29#include <linux/posix_acl_xattr.h>
30
31
32/*
33 * Locking scheme:
34 * - all ACL updates are protected by inode->i_mutex, which is taken before
35 * calling into this file.
36 */
37
38STATIC struct posix_acl *
39xfs_acl_from_disk(
40 const struct xfs_acl *aclp,
41 int len,
42 int max_entries)
43{
44 struct posix_acl_entry *acl_e;
45 struct posix_acl *acl;
46 const struct xfs_acl_entry *ace;
47 unsigned int count, i;
48
49 if (len < sizeof(*aclp))
50 return ERR_PTR(-EFSCORRUPTED);
51 count = be32_to_cpu(aclp->acl_cnt);
52 if (count > max_entries || XFS_ACL_SIZE(count) != len)
53 return ERR_PTR(-EFSCORRUPTED);
54
55 acl = posix_acl_alloc(count, GFP_KERNEL);
56 if (!acl)
57 return ERR_PTR(-ENOMEM);
58
59 for (i = 0; i < count; i++) {
60 acl_e = &acl->a_entries[i];
61 ace = &aclp->acl_entry[i];
62
63 /*
64 * The tag is 32 bits on disk and 16 bits in core.
65 *
66 * Because every access to it goes through the core
67 * format first this is not a problem.
68 */
69 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
70 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
71
72 switch (acl_e->e_tag) {
73 case ACL_USER:
74 acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id));
75 break;
76 case ACL_GROUP:
77 acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id));
78 break;
79 case ACL_USER_OBJ:
80 case ACL_GROUP_OBJ:
81 case ACL_MASK:
82 case ACL_OTHER:
83 break;
84 default:
85 goto fail;
86 }
87 }
88 return acl;
89
90fail:
91 posix_acl_release(acl);
92 return ERR_PTR(-EINVAL);
93}
94
95STATIC void
96xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
97{
98 const struct posix_acl_entry *acl_e;
99 struct xfs_acl_entry *ace;
100 int i;
101
102 aclp->acl_cnt = cpu_to_be32(acl->a_count);
103 for (i = 0; i < acl->a_count; i++) {
104 ace = &aclp->acl_entry[i];
105 acl_e = &acl->a_entries[i];
106
107 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
108 switch (acl_e->e_tag) {
109 case ACL_USER:
110 ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid));
111 break;
112 case ACL_GROUP:
113 ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid));
114 break;
115 default:
116 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
117 break;
118 }
119
120 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
121 }
122}
123
124struct posix_acl *
125xfs_get_acl(struct inode *inode, int type)
126{
127 struct xfs_inode *ip = XFS_I(inode);
128 struct posix_acl *acl = NULL;
129 struct xfs_acl *xfs_acl;
130 unsigned char *ea_name;
131 int error;
132 int len;
133
134 trace_xfs_get_acl(ip);
135
136 switch (type) {
137 case ACL_TYPE_ACCESS:
138 ea_name = SGI_ACL_FILE;
139 break;
140 case ACL_TYPE_DEFAULT:
141 ea_name = SGI_ACL_DEFAULT;
142 break;
143 default:
144 BUG();
145 }
146
147 /*
148 * If we have a cached ACLs value just return it, not need to
149 * go out to the disk.
150 */
151 len = XFS_ACL_MAX_SIZE(ip->i_mount);
152 xfs_acl = kmem_zalloc_large(len, KM_SLEEP);
153 if (!xfs_acl)
154 return ERR_PTR(-ENOMEM);
155
156 error = xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
157 &len, ATTR_ROOT);
158 if (error) {
159 /*
160 * If the attribute doesn't exist make sure we have a negative
161 * cache entry, for any other error assume it is transient.
162 */
163 if (error != -ENOATTR)
164 acl = ERR_PTR(error);
165 } else {
166 acl = xfs_acl_from_disk(xfs_acl, len,
167 XFS_ACL_MAX_ENTRIES(ip->i_mount));
168 }
169 kmem_free(xfs_acl);
170 return acl;
171}
172
173STATIC int
174__xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
175{
176 struct xfs_inode *ip = XFS_I(inode);
177 unsigned char *ea_name;
178 int error;
179
180 switch (type) {
181 case ACL_TYPE_ACCESS:
182 ea_name = SGI_ACL_FILE;
183 break;
184 case ACL_TYPE_DEFAULT:
185 if (!S_ISDIR(inode->i_mode))
186 return acl ? -EACCES : 0;
187 ea_name = SGI_ACL_DEFAULT;
188 break;
189 default:
190 return -EINVAL;
191 }
192
193 if (acl) {
194 struct xfs_acl *xfs_acl;
195 int len = XFS_ACL_MAX_SIZE(ip->i_mount);
196
197 xfs_acl = kmem_zalloc_large(len, KM_SLEEP);
198 if (!xfs_acl)
199 return -ENOMEM;
200
201 xfs_acl_to_disk(xfs_acl, acl);
202
203 /* subtract away the unused acl entries */
204 len -= sizeof(struct xfs_acl_entry) *
205 (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count);
206
207 error = xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
208 len, ATTR_ROOT);
209
210 kmem_free(xfs_acl);
211 } else {
212 /*
213 * A NULL ACL argument means we want to remove the ACL.
214 */
215 error = xfs_attr_remove(ip, ea_name, ATTR_ROOT);
216
217 /*
218 * If the attribute didn't exist to start with that's fine.
219 */
220 if (error == -ENOATTR)
221 error = 0;
222 }
223
224 if (!error)
225 set_cached_acl(inode, type, acl);
226 return error;
227}
228
229static int
230xfs_set_mode(struct inode *inode, umode_t mode)
231{
232 int error = 0;
233
234 if (mode != inode->i_mode) {
235 struct iattr iattr;
236
237 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
238 iattr.ia_mode = mode;
239 iattr.ia_ctime = current_time(inode);
240
241 error = xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
242 }
243
244 return error;
245}
246
247int
248xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
249{
250 int error = 0;
251
252 if (!acl)
253 goto set_acl;
254
255 error = -E2BIG;
256 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
257 return error;
258
259 if (type == ACL_TYPE_ACCESS) {
260 umode_t mode;
261
262 error = posix_acl_update_mode(inode, &mode, &acl);
263 if (error)
264 return error;
265 error = xfs_set_mode(inode, mode);
266 if (error)
267 return error;
268 }
269
270 set_acl:
271 return __xfs_set_acl(inode, type, acl);
272}