1 /*
2 * fs/cifs/xattr.c
3 *
4 * Copyright (c) International Business Machines Corp., 2003, 2007
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as published
9 * by the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 * the GNU Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22 #include <linux/fs.h>
23 #include <linux/posix_acl_xattr.h>
24 #include <linux/slab.h>
25 #include <linux/xattr.h>
26 #include "cifsfs.h"
27 #include "cifspdu.h"
28 #include "cifsglob.h"
29 #include "cifsproto.h"
30 #include "cifs_debug.h"
31 #include "cifs_fs_sb.h"
32 #include "cifs_unicode.h"
33
34 #define MAX_EA_VALUE_SIZE CIFSMaxBufSize
35 #define CIFS_XATTR_CIFS_ACL "system.cifs_acl"
36 #define CIFS_XATTR_ATTRIB "cifs.dosattrib" /* full name: user.cifs.dosattrib */
37 #define CIFS_XATTR_CREATETIME "cifs.creationtime" /* user.cifs.creationtime */
38 /* BB need to add server (Samba e.g) support for security and trusted prefix */
39
40 enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT };
41
cifs_xattr_set(const struct xattr_handler * handler,struct dentry * dentry,struct inode * inode,const char * name,const void * value,size_t size,int flags)42 static int cifs_xattr_set(const struct xattr_handler *handler,
43 struct dentry *dentry, struct inode *inode,
44 const char *name, const void *value,
45 size_t size, int flags)
46 {
47 int rc = -EOPNOTSUPP;
48 unsigned int xid;
49 struct super_block *sb = dentry->d_sb;
50 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
51 struct tcon_link *tlink;
52 struct cifs_tcon *pTcon;
53 char *full_path;
54
55 tlink = cifs_sb_tlink(cifs_sb);
56 if (IS_ERR(tlink))
57 return PTR_ERR(tlink);
58 pTcon = tlink_tcon(tlink);
59
60 xid = get_xid();
61
62 full_path = build_path_from_dentry(dentry);
63 if (full_path == NULL) {
64 rc = -ENOMEM;
65 goto out;
66 }
67 /* return dos attributes as pseudo xattr */
68 /* return alt name if available as pseudo attr */
69
70 /* if proc/fs/cifs/streamstoxattr is set then
71 search server for EAs or streams to
72 returns as xattrs */
73 if (size > MAX_EA_VALUE_SIZE) {
74 cifs_dbg(FYI, "size of EA value too large\n");
75 rc = -EOPNOTSUPP;
76 goto out;
77 }
78
79 switch (handler->flags) {
80 case XATTR_USER:
81 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
82 goto out;
83
84 if (pTcon->ses->server->ops->set_EA)
85 rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
86 full_path, name, value, (__u16)size,
87 cifs_sb->local_nls, cifs_sb);
88 break;
89
90 case XATTR_CIFS_ACL: {
91 #ifdef CONFIG_CIFS_ACL
92 struct cifs_ntsd *pacl;
93
94 if (!value)
95 goto out;
96 pacl = kmalloc(size, GFP_KERNEL);
97 if (!pacl) {
98 rc = -ENOMEM;
99 } else {
100 memcpy(pacl, value, size);
101 if (value &&
102 pTcon->ses->server->ops->set_acl)
103 rc = pTcon->ses->server->ops->set_acl(pacl,
104 size, inode,
105 full_path, CIFS_ACL_DACL);
106 else
107 rc = -EOPNOTSUPP;
108 if (rc == 0) /* force revalidate of the inode */
109 CIFS_I(inode)->time = 0;
110 kfree(pacl);
111 }
112 #endif /* CONFIG_CIFS_ACL */
113 break;
114 }
115
116 case XATTR_ACL_ACCESS:
117 #ifdef CONFIG_CIFS_POSIX
118 if (!value)
119 goto out;
120 if (sb->s_flags & MS_POSIXACL)
121 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
122 value, (const int)size,
123 ACL_TYPE_ACCESS, cifs_sb->local_nls,
124 cifs_remap(cifs_sb));
125 #endif /* CONFIG_CIFS_POSIX */
126 break;
127
128 case XATTR_ACL_DEFAULT:
129 #ifdef CONFIG_CIFS_POSIX
130 if (!value)
131 goto out;
132 if (sb->s_flags & MS_POSIXACL)
133 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
134 value, (const int)size,
135 ACL_TYPE_DEFAULT, cifs_sb->local_nls,
136 cifs_remap(cifs_sb));
137 #endif /* CONFIG_CIFS_POSIX */
138 break;
139 }
140
141 out:
142 kfree(full_path);
143 free_xid(xid);
144 cifs_put_tlink(tlink);
145 return rc;
146 }
147
cifs_attrib_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)148 static int cifs_attrib_get(struct dentry *dentry,
149 struct inode *inode, void *value,
150 size_t size)
151 {
152 ssize_t rc;
153 __u32 *pattribute;
154
155 rc = cifs_revalidate_dentry_attr(dentry);
156
157 if (rc)
158 return rc;
159
160 if ((value == NULL) || (size == 0))
161 return sizeof(__u32);
162 else if (size < sizeof(__u32))
163 return -ERANGE;
164
165 /* return dos attributes as pseudo xattr */
166 pattribute = (__u32 *)value;
167 *pattribute = CIFS_I(inode)->cifsAttrs;
168
169 return sizeof(__u32);
170 }
171
cifs_creation_time_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)172 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
173 void *value, size_t size)
174 {
175 ssize_t rc;
176 __u64 * pcreatetime;
177
178 rc = cifs_revalidate_dentry_attr(dentry);
179 if (rc)
180 return rc;
181
182 if ((value == NULL) || (size == 0))
183 return sizeof(__u64);
184 else if (size < sizeof(__u64))
185 return -ERANGE;
186
187 /* return dos attributes as pseudo xattr */
188 pcreatetime = (__u64 *)value;
189 *pcreatetime = CIFS_I(inode)->createtime;
190 return sizeof(__u64);
191 }
192
193
cifs_xattr_get(const struct xattr_handler * handler,struct dentry * dentry,struct inode * inode,const char * name,void * value,size_t size)194 static int cifs_xattr_get(const struct xattr_handler *handler,
195 struct dentry *dentry, struct inode *inode,
196 const char *name, void *value, size_t size)
197 {
198 ssize_t rc = -EOPNOTSUPP;
199 unsigned int xid;
200 struct super_block *sb = dentry->d_sb;
201 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
202 struct tcon_link *tlink;
203 struct cifs_tcon *pTcon;
204 char *full_path;
205
206 tlink = cifs_sb_tlink(cifs_sb);
207 if (IS_ERR(tlink))
208 return PTR_ERR(tlink);
209 pTcon = tlink_tcon(tlink);
210
211 xid = get_xid();
212
213 full_path = build_path_from_dentry(dentry);
214 if (full_path == NULL) {
215 rc = -ENOMEM;
216 goto out;
217 }
218
219 /* return alt name if available as pseudo attr */
220 switch (handler->flags) {
221 case XATTR_USER:
222 cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
223 if (strcmp(name, CIFS_XATTR_ATTRIB) == 0) {
224 rc = cifs_attrib_get(dentry, inode, value, size);
225 break;
226 } else if (strcmp(name, CIFS_XATTR_CREATETIME) == 0) {
227 rc = cifs_creation_time_get(dentry, inode, value, size);
228 break;
229 }
230
231 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
232 goto out;
233
234 if (pTcon->ses->server->ops->query_all_EAs)
235 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
236 full_path, name, value, size, cifs_sb);
237 break;
238
239 case XATTR_CIFS_ACL: {
240 #ifdef CONFIG_CIFS_ACL
241 u32 acllen;
242 struct cifs_ntsd *pacl;
243
244 if (pTcon->ses->server->ops->get_acl == NULL)
245 goto out; /* rc already EOPNOTSUPP */
246
247 pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
248 inode, full_path, &acllen);
249 if (IS_ERR(pacl)) {
250 rc = PTR_ERR(pacl);
251 cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
252 __func__, rc);
253 } else {
254 if (value) {
255 if (acllen > size)
256 acllen = -ERANGE;
257 else
258 memcpy(value, pacl, acllen);
259 }
260 rc = acllen;
261 kfree(pacl);
262 }
263 #endif /* CONFIG_CIFS_ACL */
264 break;
265 }
266
267 case XATTR_ACL_ACCESS:
268 #ifdef CONFIG_CIFS_POSIX
269 if (sb->s_flags & MS_POSIXACL)
270 rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
271 value, size, ACL_TYPE_ACCESS,
272 cifs_sb->local_nls,
273 cifs_remap(cifs_sb));
274 #endif /* CONFIG_CIFS_POSIX */
275 break;
276
277 case XATTR_ACL_DEFAULT:
278 #ifdef CONFIG_CIFS_POSIX
279 if (sb->s_flags & MS_POSIXACL)
280 rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
281 value, size, ACL_TYPE_DEFAULT,
282 cifs_sb->local_nls,
283 cifs_remap(cifs_sb));
284 #endif /* CONFIG_CIFS_POSIX */
285 break;
286 }
287
288 /* We could add an additional check for streams ie
289 if proc/fs/cifs/streamstoxattr is set then
290 search server for EAs or streams to
291 returns as xattrs */
292
293 if (rc == -EINVAL)
294 rc = -EOPNOTSUPP;
295
296 out:
297 kfree(full_path);
298 free_xid(xid);
299 cifs_put_tlink(tlink);
300 return rc;
301 }
302
cifs_listxattr(struct dentry * direntry,char * data,size_t buf_size)303 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
304 {
305 ssize_t rc = -EOPNOTSUPP;
306 unsigned int xid;
307 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
308 struct tcon_link *tlink;
309 struct cifs_tcon *pTcon;
310 char *full_path;
311
312 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
313 return -EOPNOTSUPP;
314
315 tlink = cifs_sb_tlink(cifs_sb);
316 if (IS_ERR(tlink))
317 return PTR_ERR(tlink);
318 pTcon = tlink_tcon(tlink);
319
320 xid = get_xid();
321
322 full_path = build_path_from_dentry(direntry);
323 if (full_path == NULL) {
324 rc = -ENOMEM;
325 goto list_ea_exit;
326 }
327 /* return dos attributes as pseudo xattr */
328 /* return alt name if available as pseudo attr */
329
330 /* if proc/fs/cifs/streamstoxattr is set then
331 search server for EAs or streams to
332 returns as xattrs */
333
334 if (pTcon->ses->server->ops->query_all_EAs)
335 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
336 full_path, NULL, data, buf_size, cifs_sb);
337 list_ea_exit:
338 kfree(full_path);
339 free_xid(xid);
340 cifs_put_tlink(tlink);
341 return rc;
342 }
343
344 static const struct xattr_handler cifs_user_xattr_handler = {
345 .prefix = XATTR_USER_PREFIX,
346 .flags = XATTR_USER,
347 .get = cifs_xattr_get,
348 .set = cifs_xattr_set,
349 };
350
351 /* os2.* attributes are treated like user.* attributes */
352 static const struct xattr_handler cifs_os2_xattr_handler = {
353 .prefix = XATTR_OS2_PREFIX,
354 .flags = XATTR_USER,
355 .get = cifs_xattr_get,
356 .set = cifs_xattr_set,
357 };
358
359 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
360 .name = CIFS_XATTR_CIFS_ACL,
361 .flags = XATTR_CIFS_ACL,
362 .get = cifs_xattr_get,
363 .set = cifs_xattr_set,
364 };
365
366 static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
367 .name = XATTR_NAME_POSIX_ACL_ACCESS,
368 .flags = XATTR_ACL_ACCESS,
369 .get = cifs_xattr_get,
370 .set = cifs_xattr_set,
371 };
372
373 static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
374 .name = XATTR_NAME_POSIX_ACL_DEFAULT,
375 .flags = XATTR_ACL_DEFAULT,
376 .get = cifs_xattr_get,
377 .set = cifs_xattr_set,
378 };
379
380 const struct xattr_handler *cifs_xattr_handlers[] = {
381 &cifs_user_xattr_handler,
382 &cifs_os2_xattr_handler,
383 &cifs_cifs_acl_xattr_handler,
384 &cifs_posix_acl_access_xattr_handler,
385 &cifs_posix_acl_default_xattr_handler,
386 NULL
387 };
388