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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// 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 <linux/posix_acl_xattr.h>
16
17
18/*
19 * Locking scheme:
20 * - all ACL updates are protected by inode->i_mutex, which is taken before
21 * calling into this file.
22 */
23
24STATIC struct posix_acl *
25xfs_acl_from_disk(
26 const struct xfs_acl *aclp,
27 int len,
28 int max_entries)
29{
30 struct posix_acl_entry *acl_e;
31 struct posix_acl *acl;
32 const struct xfs_acl_entry *ace;
33 unsigned int count, i;
34
35 if (len < sizeof(*aclp))
36 return ERR_PTR(-EFSCORRUPTED);
37 count = be32_to_cpu(aclp->acl_cnt);
38 if (count > max_entries || XFS_ACL_SIZE(count) != len)
39 return ERR_PTR(-EFSCORRUPTED);
40
41 acl = posix_acl_alloc(count, GFP_KERNEL);
42 if (!acl)
43 return ERR_PTR(-ENOMEM);
44
45 for (i = 0; i < count; i++) {
46 acl_e = &acl->a_entries[i];
47 ace = &aclp->acl_entry[i];
48
49 /*
50 * The tag is 32 bits on disk and 16 bits in core.
51 *
52 * Because every access to it goes through the core
53 * format first this is not a problem.
54 */
55 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
56 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
57
58 switch (acl_e->e_tag) {
59 case ACL_USER:
60 acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id));
61 break;
62 case ACL_GROUP:
63 acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id));
64 break;
65 case ACL_USER_OBJ:
66 case ACL_GROUP_OBJ:
67 case ACL_MASK:
68 case ACL_OTHER:
69 break;
70 default:
71 goto fail;
72 }
73 }
74 return acl;
75
76fail:
77 posix_acl_release(acl);
78 return ERR_PTR(-EINVAL);
79}
80
81STATIC void
82xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
83{
84 const struct posix_acl_entry *acl_e;
85 struct xfs_acl_entry *ace;
86 int i;
87
88 aclp->acl_cnt = cpu_to_be32(acl->a_count);
89 for (i = 0; i < acl->a_count; i++) {
90 ace = &aclp->acl_entry[i];
91 acl_e = &acl->a_entries[i];
92
93 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
94 switch (acl_e->e_tag) {
95 case ACL_USER:
96 ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid));
97 break;
98 case ACL_GROUP:
99 ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid));
100 break;
101 default:
102 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
103 break;
104 }
105
106 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
107 }
108}
109
110struct posix_acl *
111xfs_get_acl(struct inode *inode, int type)
112{
113 struct xfs_inode *ip = XFS_I(inode);
114 struct posix_acl *acl = NULL;
115 struct xfs_acl *xfs_acl = NULL;
116 unsigned char *ea_name;
117 int error;
118 int len;
119
120 trace_xfs_get_acl(ip);
121
122 switch (type) {
123 case ACL_TYPE_ACCESS:
124 ea_name = SGI_ACL_FILE;
125 break;
126 case ACL_TYPE_DEFAULT:
127 ea_name = SGI_ACL_DEFAULT;
128 break;
129 default:
130 BUG();
131 }
132
133 /*
134 * If we have a cached ACLs value just return it, not need to
135 * go out to the disk.
136 */
137 len = XFS_ACL_MAX_SIZE(ip->i_mount);
138 error = xfs_attr_get(ip, ea_name, (unsigned char **)&xfs_acl, &len,
139 ATTR_ALLOC | ATTR_ROOT);
140 if (error) {
141 /*
142 * If the attribute doesn't exist make sure we have a negative
143 * cache entry, for any other error assume it is transient.
144 */
145 if (error != -ENOATTR)
146 acl = ERR_PTR(error);
147 } else {
148 acl = xfs_acl_from_disk(xfs_acl, len,
149 XFS_ACL_MAX_ENTRIES(ip->i_mount));
150 kmem_free(xfs_acl);
151 }
152 return acl;
153}
154
155int
156__xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
157{
158 struct xfs_inode *ip = XFS_I(inode);
159 unsigned char *ea_name;
160 int error;
161
162 switch (type) {
163 case ACL_TYPE_ACCESS:
164 ea_name = SGI_ACL_FILE;
165 break;
166 case ACL_TYPE_DEFAULT:
167 if (!S_ISDIR(inode->i_mode))
168 return acl ? -EACCES : 0;
169 ea_name = SGI_ACL_DEFAULT;
170 break;
171 default:
172 return -EINVAL;
173 }
174
175 if (acl) {
176 struct xfs_acl *xfs_acl;
177 int len = XFS_ACL_MAX_SIZE(ip->i_mount);
178
179 xfs_acl = kmem_zalloc_large(len, 0);
180 if (!xfs_acl)
181 return -ENOMEM;
182
183 xfs_acl_to_disk(xfs_acl, acl);
184
185 /* subtract away the unused acl entries */
186 len -= sizeof(struct xfs_acl_entry) *
187 (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count);
188
189 error = xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
190 len, ATTR_ROOT);
191
192 kmem_free(xfs_acl);
193 } else {
194 /*
195 * A NULL ACL argument means we want to remove the ACL.
196 */
197 error = xfs_attr_remove(ip, ea_name, ATTR_ROOT);
198
199 /*
200 * If the attribute didn't exist to start with that's fine.
201 */
202 if (error == -ENOATTR)
203 error = 0;
204 }
205
206 if (!error)
207 set_cached_acl(inode, type, acl);
208 return error;
209}
210
211static int
212xfs_set_mode(struct inode *inode, umode_t mode)
213{
214 int error = 0;
215
216 if (mode != inode->i_mode) {
217 struct iattr iattr;
218
219 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
220 iattr.ia_mode = mode;
221 iattr.ia_ctime = current_time(inode);
222
223 error = xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
224 }
225
226 return error;
227}
228
229int
230xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
231{
232 umode_t mode;
233 bool set_mode = false;
234 int error = 0;
235
236 if (!acl)
237 goto set_acl;
238
239 error = -E2BIG;
240 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
241 return error;
242
243 if (type == ACL_TYPE_ACCESS) {
244 error = posix_acl_update_mode(inode, &mode, &acl);
245 if (error)
246 return error;
247 set_mode = true;
248 }
249
250 set_acl:
251 error = __xfs_set_acl(inode, acl, type);
252 if (error)
253 return error;
254
255 /*
256 * We set the mode after successfully updating the ACL xattr because the
257 * xattr update can fail at ENOSPC and we don't want to change the mode
258 * if the ACL update hasn't been applied.
259 */
260 if (set_mode)
261 error = xfs_set_mode(inode, mode);
262
263 return error;
264}