[go: up one dir, main page]
1// SPDX-License-Identifier: LGPL-2.1
2/*
3 * Copyright IBM Corporation, 2010
4 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
5 */
6
7#include <linux/module.h>
8#include <linux/fs.h>
9#include <linux/fs_struct.h>
10#include <net/9p/9p.h>
11#include <net/9p/client.h>
12#include <linux/slab.h>
13#include <linux/sched.h>
14#include <linux/posix_acl_xattr.h>
15#include "xattr.h"
16#include "acl.h"
17#include "v9fs.h"
18#include "v9fs_vfs.h"
19#include "fid.h"
20
21static struct posix_acl *v9fs_fid_get_acl(struct p9_fid *fid, const char *name)
22{
23 ssize_t size;
24 void *value = NULL;
25 struct posix_acl *acl = NULL;
26
27 size = v9fs_fid_xattr_get(fid, name, NULL, buffer_size: 0);
28 if (size < 0)
29 return ERR_PTR(error: size);
30 if (size == 0)
31 return ERR_PTR(error: -ENODATA);
32
33 value = kzalloc(size, GFP_NOFS);
34 if (!value)
35 return ERR_PTR(error: -ENOMEM);
36
37 size = v9fs_fid_xattr_get(fid, name, buffer: value, buffer_size: size);
38 if (size < 0)
39 acl = ERR_PTR(error: size);
40 else if (size == 0)
41 acl = ERR_PTR(error: -ENODATA);
42 else
43 acl = posix_acl_from_xattr(user_ns: &init_user_ns, value, size);
44 kfree(objp: value);
45 return acl;
46}
47
48static struct posix_acl *v9fs_acl_get(struct dentry *dentry, const char *name)
49{
50 struct p9_fid *fid;
51 struct posix_acl *acl = NULL;
52
53 fid = v9fs_fid_lookup(dentry);
54 if (IS_ERR(ptr: fid))
55 return ERR_CAST(ptr: fid);
56
57 acl = v9fs_fid_get_acl(fid, name);
58 p9_fid_put(fid);
59 return acl;
60}
61
62static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, const char *name)
63{
64 int retval;
65 struct posix_acl *acl = NULL;
66
67 acl = v9fs_fid_get_acl(fid, name);
68 if (!IS_ERR(ptr: acl))
69 return acl;
70
71 retval = PTR_ERR(ptr: acl);
72 if (retval == -ENODATA || retval == -ENOSYS || retval == -EOPNOTSUPP)
73 return NULL;
74
75 /* map everything else to -EIO */
76 return ERR_PTR(error: -EIO);
77}
78
79int v9fs_get_acl(struct inode *inode, struct p9_fid *fid)
80{
81 int retval = 0;
82 struct posix_acl *pacl, *dacl;
83 struct v9fs_session_info *v9ses;
84
85 v9ses = v9fs_inode2v9ses(inode);
86 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
87 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
88 set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL);
89 set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
90 return 0;
91 }
92 /* get the default/access acl values and cache them */
93 dacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_DEFAULT);
94 pacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_ACCESS);
95
96 if (!IS_ERR(ptr: dacl) && !IS_ERR(ptr: pacl)) {
97 set_cached_acl(inode, ACL_TYPE_DEFAULT, acl: dacl);
98 set_cached_acl(inode, ACL_TYPE_ACCESS, acl: pacl);
99 } else
100 retval = -EIO;
101
102 if (!IS_ERR(ptr: dacl))
103 posix_acl_release(acl: dacl);
104
105 if (!IS_ERR(ptr: pacl))
106 posix_acl_release(acl: pacl);
107
108 return retval;
109}
110
111static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)
112{
113 struct posix_acl *acl;
114 /*
115 * 9p Always cache the acl value when
116 * instantiating the inode (v9fs_inode_from_fid)
117 */
118 acl = get_cached_acl(inode, type);
119 BUG_ON(is_uncached_acl(acl));
120 return acl;
121}
122
123struct posix_acl *v9fs_iop_get_inode_acl(struct inode *inode, int type, bool rcu)
124{
125 struct v9fs_session_info *v9ses;
126
127 if (rcu)
128 return ERR_PTR(error: -ECHILD);
129
130 v9ses = v9fs_inode2v9ses(inode);
131 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
132 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
133 /*
134 * On access = client and acl = on mode get the acl
135 * values from the server
136 */
137 return NULL;
138 }
139 return v9fs_get_cached_acl(inode, type);
140
141}
142
143struct posix_acl *v9fs_iop_get_acl(struct mnt_idmap *idmap,
144 struct dentry *dentry, int type)
145{
146 struct v9fs_session_info *v9ses;
147
148 v9ses = v9fs_dentry2v9ses(dentry);
149 /* We allow set/get/list of acl when access=client is not specified. */
150 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
151 return v9fs_acl_get(dentry, name: posix_acl_xattr_name(type));
152 return v9fs_get_cached_acl(inode: d_inode(dentry), type);
153}
154
155int v9fs_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
156 struct posix_acl *acl, int type)
157{
158 int retval;
159 size_t size = 0;
160 void *value = NULL;
161 const char *acl_name;
162 struct v9fs_session_info *v9ses;
163 struct inode *inode = d_inode(dentry);
164
165 if (acl) {
166 retval = posix_acl_valid(inode->i_sb->s_user_ns, acl);
167 if (retval)
168 goto err_out;
169
170 size = posix_acl_xattr_size(count: acl->a_count);
171
172 value = kzalloc(size, GFP_NOFS);
173 if (!value) {
174 retval = -ENOMEM;
175 goto err_out;
176 }
177
178 retval = posix_acl_to_xattr(user_ns: &init_user_ns, acl, buffer: value, size);
179 if (retval < 0)
180 goto err_out;
181 }
182
183 /*
184 * set the attribute on the remote. Without even looking at the
185 * xattr value. We leave it to the server to validate
186 */
187 acl_name = posix_acl_xattr_name(type);
188 v9ses = v9fs_dentry2v9ses(dentry);
189 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) {
190 retval = v9fs_xattr_set(dentry, name: acl_name, value, value_len: size, flags: 0);
191 goto err_out;
192 }
193
194 if (S_ISLNK(inode->i_mode)) {
195 retval = -EOPNOTSUPP;
196 goto err_out;
197 }
198
199 if (!inode_owner_or_capable(idmap: &nop_mnt_idmap, inode)) {
200 retval = -EPERM;
201 goto err_out;
202 }
203
204 switch (type) {
205 case ACL_TYPE_ACCESS:
206 if (acl) {
207 struct iattr iattr = {};
208 struct posix_acl *acl_mode = acl;
209
210 retval = posix_acl_update_mode(&nop_mnt_idmap, inode,
211 &iattr.ia_mode,
212 &acl_mode);
213 if (retval)
214 goto err_out;
215 if (!acl_mode) {
216 /*
217 * ACL can be represented by the mode bits.
218 * So don't update ACL below.
219 */
220 kfree(objp: value);
221 value = NULL;
222 size = 0;
223 }
224 iattr.ia_valid = ATTR_MODE;
225 /*
226 * FIXME should we update ctime ?
227 * What is the following setxattr update the mode ?
228 */
229 v9fs_vfs_setattr_dotl(idmap: &nop_mnt_idmap, dentry, iattr: &iattr);
230 }
231 break;
232 case ACL_TYPE_DEFAULT:
233 if (!S_ISDIR(inode->i_mode)) {
234 retval = acl ? -EINVAL : 0;
235 goto err_out;
236 }
237 break;
238 }
239
240 retval = v9fs_xattr_set(dentry, name: acl_name, value, value_len: size, flags: 0);
241 if (!retval)
242 set_cached_acl(inode, type, acl);
243
244err_out:
245 kfree(objp: value);
246 return retval;
247}
248
249static int v9fs_set_acl(struct p9_fid *fid, int type, struct posix_acl *acl)
250{
251 int retval;
252 char *name;
253 size_t size;
254 void *buffer;
255
256 if (!acl)
257 return 0;
258
259 /* Set a setxattr request to server */
260 size = posix_acl_xattr_size(count: acl->a_count);
261 buffer = kmalloc(size, GFP_KERNEL);
262 if (!buffer)
263 return -ENOMEM;
264 retval = posix_acl_to_xattr(user_ns: &init_user_ns, acl, buffer, size);
265 if (retval < 0)
266 goto err_free_out;
267 switch (type) {
268 case ACL_TYPE_ACCESS:
269 name = XATTR_NAME_POSIX_ACL_ACCESS;
270 break;
271 case ACL_TYPE_DEFAULT:
272 name = XATTR_NAME_POSIX_ACL_DEFAULT;
273 break;
274 default:
275 BUG();
276 }
277 retval = v9fs_fid_xattr_set(fid, name, value: buffer, value_len: size, flags: 0);
278err_free_out:
279 kfree(objp: buffer);
280 return retval;
281}
282
283int v9fs_acl_chmod(struct inode *inode, struct p9_fid *fid)
284{
285 int retval = 0;
286 struct posix_acl *acl;
287
288 if (S_ISLNK(inode->i_mode))
289 return -EOPNOTSUPP;
290 acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
291 if (acl) {
292 retval = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
293 if (retval)
294 return retval;
295 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
296 retval = v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);
297 posix_acl_release(acl);
298 }
299 return retval;
300}
301
302int v9fs_set_create_acl(struct inode *inode, struct p9_fid *fid,
303 struct posix_acl *dacl, struct posix_acl *acl)
304{
305 set_cached_acl(inode, ACL_TYPE_DEFAULT, acl: dacl);
306 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
307 v9fs_set_acl(fid, ACL_TYPE_DEFAULT, acl: dacl);
308 v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);
309 return 0;
310}
311
312void v9fs_put_acl(struct posix_acl *dacl,
313 struct posix_acl *acl)
314{
315 posix_acl_release(acl: dacl);
316 posix_acl_release(acl);
317}
318
319int v9fs_acl_mode(struct inode *dir, umode_t *modep,
320 struct posix_acl **dpacl, struct posix_acl **pacl)
321{
322 int retval = 0;
323 umode_t mode = *modep;
324 struct posix_acl *acl = NULL;
325
326 if (!S_ISLNK(mode)) {
327 acl = v9fs_get_cached_acl(inode: dir, ACL_TYPE_DEFAULT);
328 if (IS_ERR(ptr: acl))
329 return PTR_ERR(ptr: acl);
330 if (!acl)
331 mode &= ~current_umask();
332 }
333 if (acl) {
334 if (S_ISDIR(mode))
335 *dpacl = posix_acl_dup(acl);
336 retval = __posix_acl_create(&acl, GFP_NOFS, &mode);
337 if (retval < 0)
338 return retval;
339 if (retval > 0)
340 *pacl = acl;
341 else
342 posix_acl_release(acl);
343 }
344 *modep = mode;
345 return 0;
346}
347

source code of linux/fs/9p/acl.c