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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_ag.h"
23#include "xfs_sb.h"
24#include "xfs_mount.h"
25#include "xfs_inode.h"
26#include "xfs_acl.h"
27#include "xfs_attr.h"
28#include "xfs_trace.h"
29#include <linux/slab.h>
30#include <linux/xattr.h>
31#include <linux/posix_acl_xattr.h>
32
33
34/*
35 * Locking scheme:
36 * - all ACL updates are protected by inode->i_mutex, which is taken before
37 * calling into this file.
38 */
39
40STATIC struct posix_acl *
41xfs_acl_from_disk(
42 struct xfs_acl *aclp,
43 int max_entries)
44{
45 struct posix_acl_entry *acl_e;
46 struct posix_acl *acl;
47 struct xfs_acl_entry *ace;
48 unsigned int count, i;
49
50 count = be32_to_cpu(aclp->acl_cnt);
51 if (count > max_entries)
52 return ERR_PTR(-EFSCORRUPTED);
53
54 acl = posix_acl_alloc(count, GFP_KERNEL);
55 if (!acl)
56 return ERR_PTR(-ENOMEM);
57
58 for (i = 0; i < count; i++) {
59 acl_e = &acl->a_entries[i];
60 ace = &aclp->acl_entry[i];
61
62 /*
63 * The tag is 32 bits on disk and 16 bits in core.
64 *
65 * Because every access to it goes through the core
66 * format first this is not a problem.
67 */
68 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
69 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
70
71 switch (acl_e->e_tag) {
72 case ACL_USER:
73 acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id));
74 break;
75 case ACL_GROUP:
76 acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id));
77 break;
78 case ACL_USER_OBJ:
79 case ACL_GROUP_OBJ:
80 case ACL_MASK:
81 case ACL_OTHER:
82 break;
83 default:
84 goto fail;
85 }
86 }
87 return acl;
88
89fail:
90 posix_acl_release(acl);
91 return ERR_PTR(-EINVAL);
92}
93
94STATIC void
95xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
96{
97 const struct posix_acl_entry *acl_e;
98 struct xfs_acl_entry *ace;
99 int i;
100
101 aclp->acl_cnt = cpu_to_be32(acl->a_count);
102 for (i = 0; i < acl->a_count; i++) {
103 ace = &aclp->acl_entry[i];
104 acl_e = &acl->a_entries[i];
105
106 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
107 switch (acl_e->e_tag) {
108 case ACL_USER:
109 ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid));
110 break;
111 case ACL_GROUP:
112 ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid));
113 break;
114 default:
115 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
116 break;
117 }
118
119 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
120 }
121}
122
123struct posix_acl *
124xfs_get_acl(struct inode *inode, int type)
125{
126 struct xfs_inode *ip = XFS_I(inode);
127 struct posix_acl *acl = NULL;
128 struct xfs_acl *xfs_acl;
129 unsigned char *ea_name;
130 int error;
131 int len;
132
133 trace_xfs_get_acl(ip);
134
135 switch (type) {
136 case ACL_TYPE_ACCESS:
137 ea_name = SGI_ACL_FILE;
138 break;
139 case ACL_TYPE_DEFAULT:
140 ea_name = SGI_ACL_DEFAULT;
141 break;
142 default:
143 BUG();
144 }
145
146 /*
147 * If we have a cached ACLs value just return it, not need to
148 * go out to the disk.
149 */
150 len = XFS_ACL_MAX_SIZE(ip->i_mount);
151 xfs_acl = kmem_zalloc_large(len, KM_SLEEP);
152 if (!xfs_acl)
153 return ERR_PTR(-ENOMEM);
154
155 error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
156 &len, ATTR_ROOT);
157 if (error) {
158 /*
159 * If the attribute doesn't exist make sure we have a negative
160 * cache entry, for any other error assume it is transient and
161 * leave the cache entry as ACL_NOT_CACHED.
162 */
163 if (error == -ENOATTR)
164 goto out_update_cache;
165 goto out;
166 }
167
168 acl = xfs_acl_from_disk(xfs_acl, XFS_ACL_MAX_ENTRIES(ip->i_mount));
169 if (IS_ERR(acl))
170 goto out;
171
172out_update_cache:
173 set_cached_acl(inode, type, acl);
174out:
175 kmem_free(xfs_acl);
176 return acl;
177}
178
179STATIC int
180__xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
181{
182 struct xfs_inode *ip = XFS_I(inode);
183 unsigned char *ea_name;
184 int error;
185
186 switch (type) {
187 case ACL_TYPE_ACCESS:
188 ea_name = SGI_ACL_FILE;
189 break;
190 case ACL_TYPE_DEFAULT:
191 if (!S_ISDIR(inode->i_mode))
192 return acl ? -EACCES : 0;
193 ea_name = SGI_ACL_DEFAULT;
194 break;
195 default:
196 return -EINVAL;
197 }
198
199 if (acl) {
200 struct xfs_acl *xfs_acl;
201 int len = XFS_ACL_MAX_SIZE(ip->i_mount);
202
203 xfs_acl = kmem_zalloc_large(len, KM_SLEEP);
204 if (!xfs_acl)
205 return -ENOMEM;
206
207 xfs_acl_to_disk(xfs_acl, acl);
208
209 /* subtract away the unused acl entries */
210 len -= sizeof(struct xfs_acl_entry) *
211 (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count);
212
213 error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
214 len, ATTR_ROOT);
215
216 kmem_free(xfs_acl);
217 } else {
218 /*
219 * A NULL ACL argument means we want to remove the ACL.
220 */
221 error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);
222
223 /*
224 * If the attribute didn't exist to start with that's fine.
225 */
226 if (error == -ENOATTR)
227 error = 0;
228 }
229
230 if (!error)
231 set_cached_acl(inode, type, acl);
232 return error;
233}
234
235static int
236xfs_set_mode(struct inode *inode, umode_t mode)
237{
238 int error = 0;
239
240 if (mode != inode->i_mode) {
241 struct iattr iattr;
242
243 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
244 iattr.ia_mode = mode;
245 iattr.ia_ctime = current_fs_time(inode->i_sb);
246
247 error = -xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
248 }
249
250 return error;
251}
252
253static int
254xfs_acl_exists(struct inode *inode, unsigned char *name)
255{
256 int len = XFS_ACL_MAX_SIZE(XFS_M(inode->i_sb));
257
258 return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
259 ATTR_ROOT|ATTR_KERNOVAL) == 0);
260}
261
262int
263posix_acl_access_exists(struct inode *inode)
264{
265 return xfs_acl_exists(inode, SGI_ACL_FILE);
266}
267
268int
269posix_acl_default_exists(struct inode *inode)
270{
271 if (!S_ISDIR(inode->i_mode))
272 return 0;
273 return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
274}
275
276int
277xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
278{
279 int error = 0;
280
281 if (!acl)
282 goto set_acl;
283
284 error = -E2BIG;
285 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
286 return error;
287
288 if (type == ACL_TYPE_ACCESS) {
289 umode_t mode = inode->i_mode;
290 error = posix_acl_equiv_mode(acl, &mode);
291
292 if (error <= 0) {
293 acl = NULL;
294
295 if (error < 0)
296 return error;
297 }
298
299 error = xfs_set_mode(inode, mode);
300 if (error)
301 return error;
302 }
303
304 set_acl:
305 return __xfs_set_acl(inode, type, acl);
306}
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_da_format.h"
14#include "xfs_da_btree.h"
15#include "xfs_attr.h"
16#include "xfs_trace.h"
17#include "xfs_error.h"
18#include "xfs_acl.h"
19#include "xfs_trans.h"
20#include "xfs_xattr.h"
21
22#include <linux/posix_acl_xattr.h>
23
24/*
25 * Locking scheme:
26 * - all ACL updates are protected by inode->i_mutex, which is taken before
27 * calling into this file.
28 */
29
30STATIC struct posix_acl *
31xfs_acl_from_disk(
32 struct xfs_mount *mp,
33 const struct xfs_acl *aclp,
34 int len,
35 int max_entries)
36{
37 struct posix_acl_entry *acl_e;
38 struct posix_acl *acl;
39 const struct xfs_acl_entry *ace;
40 unsigned int count, i;
41
42 if (len < sizeof(*aclp)) {
43 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
44 len);
45 return ERR_PTR(-EFSCORRUPTED);
46 }
47
48 count = be32_to_cpu(aclp->acl_cnt);
49 if (count > max_entries || XFS_ACL_SIZE(count) != len) {
50 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
51 len);
52 return ERR_PTR(-EFSCORRUPTED);
53 }
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 = make_kuid(&init_user_ns,
75 be32_to_cpu(ace->ae_id));
76 break;
77 case ACL_GROUP:
78 acl_e->e_gid = make_kgid(&init_user_ns,
79 be32_to_cpu(ace->ae_id));
80 break;
81 case ACL_USER_OBJ:
82 case ACL_GROUP_OBJ:
83 case ACL_MASK:
84 case ACL_OTHER:
85 break;
86 default:
87 goto fail;
88 }
89 }
90 return acl;
91
92fail:
93 posix_acl_release(acl);
94 return ERR_PTR(-EINVAL);
95}
96
97STATIC void
98xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
99{
100 const struct posix_acl_entry *acl_e;
101 struct xfs_acl_entry *ace;
102 int i;
103
104 aclp->acl_cnt = cpu_to_be32(acl->a_count);
105 for (i = 0; i < acl->a_count; i++) {
106 ace = &aclp->acl_entry[i];
107 acl_e = &acl->a_entries[i];
108
109 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
110 switch (acl_e->e_tag) {
111 case ACL_USER:
112 ace->ae_id = cpu_to_be32(
113 from_kuid(&init_user_ns, acl_e->e_uid));
114 break;
115 case ACL_GROUP:
116 ace->ae_id = cpu_to_be32(
117 from_kgid(&init_user_ns, acl_e->e_gid));
118 break;
119 default:
120 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
121 break;
122 }
123
124 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
125 }
126}
127
128struct posix_acl *
129xfs_get_acl(struct inode *inode, int type, bool rcu)
130{
131 struct xfs_inode *ip = XFS_I(inode);
132 struct xfs_mount *mp = ip->i_mount;
133 struct posix_acl *acl = NULL;
134 struct xfs_da_args args = {
135 .dp = ip,
136 .attr_filter = XFS_ATTR_ROOT,
137 .valuelen = XFS_ACL_MAX_SIZE(mp),
138 };
139 int error;
140
141 if (rcu)
142 return ERR_PTR(-ECHILD);
143
144 trace_xfs_get_acl(ip);
145
146 switch (type) {
147 case ACL_TYPE_ACCESS:
148 args.name = SGI_ACL_FILE;
149 break;
150 case ACL_TYPE_DEFAULT:
151 args.name = SGI_ACL_DEFAULT;
152 break;
153 default:
154 BUG();
155 }
156 args.namelen = strlen(args.name);
157
158 /*
159 * If the attribute doesn't exist make sure we have a negative cache
160 * entry, for any other error assume it is transient.
161 */
162 error = xfs_attr_get(&args);
163 if (!error) {
164 acl = xfs_acl_from_disk(mp, args.value, args.valuelen,
165 XFS_ACL_MAX_ENTRIES(mp));
166 } else if (error != -ENOATTR) {
167 acl = ERR_PTR(error);
168 }
169
170 kvfree(args.value);
171 return acl;
172}
173
174int
175__xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
176{
177 struct xfs_inode *ip = XFS_I(inode);
178 struct xfs_da_args args = {
179 .dp = ip,
180 .attr_filter = XFS_ATTR_ROOT,
181 };
182 int error;
183
184 switch (type) {
185 case ACL_TYPE_ACCESS:
186 args.name = SGI_ACL_FILE;
187 break;
188 case ACL_TYPE_DEFAULT:
189 if (!S_ISDIR(inode->i_mode))
190 return acl ? -EACCES : 0;
191 args.name = SGI_ACL_DEFAULT;
192 break;
193 default:
194 return -EINVAL;
195 }
196 args.namelen = strlen(args.name);
197
198 if (acl) {
199 args.valuelen = XFS_ACL_SIZE(acl->a_count);
200 args.value = kvzalloc(args.valuelen, GFP_KERNEL);
201 if (!args.value)
202 return -ENOMEM;
203 xfs_acl_to_disk(args.value, acl);
204 error = xfs_attr_change(&args, XFS_ATTRUPDATE_UPSERT);
205 kvfree(args.value);
206 } else {
207 error = xfs_attr_change(&args, XFS_ATTRUPDATE_REMOVE);
208 /*
209 * If the attribute didn't exist to start with that's fine.
210 */
211 if (error == -ENOATTR)
212 error = 0;
213 }
214
215 if (!error)
216 set_cached_acl(inode, type, acl);
217 return error;
218}
219
220static int
221xfs_acl_set_mode(
222 struct inode *inode,
223 umode_t mode)
224{
225 struct xfs_inode *ip = XFS_I(inode);
226 struct xfs_mount *mp = ip->i_mount;
227 struct xfs_trans *tp;
228 int error;
229
230 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
231 if (error)
232 return error;
233
234 xfs_ilock(ip, XFS_ILOCK_EXCL);
235 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
236 inode->i_mode = mode;
237 inode_set_ctime_current(inode);
238 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
239
240 if (xfs_has_wsync(mp))
241 xfs_trans_set_sync(tp);
242 return xfs_trans_commit(tp);
243}
244
245int
246xfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
247 struct posix_acl *acl, int type)
248{
249 umode_t mode;
250 bool set_mode = false;
251 int error = 0;
252 struct inode *inode = d_inode(dentry);
253
254 if (!acl)
255 goto set_acl;
256
257 error = -E2BIG;
258 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
259 return error;
260
261 if (type == ACL_TYPE_ACCESS) {
262 error = posix_acl_update_mode(idmap, inode, &mode, &acl);
263 if (error)
264 return error;
265 set_mode = true;
266 }
267
268 set_acl:
269 /*
270 * We set the mode after successfully updating the ACL xattr because the
271 * xattr update can fail at ENOSPC and we don't want to change the mode
272 * if the ACL update hasn't been applied.
273 */
274 error = __xfs_set_acl(inode, acl, type);
275 if (!error && set_mode && mode != inode->i_mode)
276 error = xfs_acl_set_mode(inode, mode);
277 return error;
278}
279
280/*
281 * Invalidate any cached ACLs if the user has bypassed the ACL interface.
282 * We don't validate the content whatsoever so it is caller responsibility to
283 * provide data in valid format and ensure i_mode is consistent.
284 */
285void
286xfs_forget_acl(
287 struct inode *inode,
288 const char *name)
289{
290 if (!strcmp(name, SGI_ACL_FILE))
291 forget_cached_acl(inode, ACL_TYPE_ACCESS);
292 else if (!strcmp(name, SGI_ACL_DEFAULT))
293 forget_cached_acl(inode, ACL_TYPE_DEFAULT);
294}