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 /*
39 * Although these three are just aliases for the above, need to move away from
40 * confusing users and using the 20+ year old term 'cifs' when it is no longer
41 * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
42 */
43 #define SMB3_XATTR_CIFS_ACL "system.smb3_acl"
44 #define SMB3_XATTR_ATTRIB "smb3.dosattrib" /* full name: user.smb3.dosattrib */
45 #define SMB3_XATTR_CREATETIME "smb3.creationtime" /* user.smb3.creationtime */
46 /* BB need to add server (Samba e.g) support for security and trusted prefix */
47
48 enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT };
49
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)50 static int cifs_xattr_set(const struct xattr_handler *handler,
51 struct dentry *dentry, struct inode *inode,
52 const char *name, const void *value,
53 size_t size, int flags)
54 {
55 int rc = -EOPNOTSUPP;
56 unsigned int xid;
57 struct super_block *sb = dentry->d_sb;
58 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
59 struct tcon_link *tlink;
60 struct cifs_tcon *pTcon;
61 char *full_path;
62
63 tlink = cifs_sb_tlink(cifs_sb);
64 if (IS_ERR(tlink))
65 return PTR_ERR(tlink);
66 pTcon = tlink_tcon(tlink);
67
68 xid = get_xid();
69
70 full_path = build_path_from_dentry(dentry);
71 if (full_path == NULL) {
72 rc = -ENOMEM;
73 goto out;
74 }
75 /* return dos attributes as pseudo xattr */
76 /* return alt name if available as pseudo attr */
77
78 /* if proc/fs/cifs/streamstoxattr is set then
79 search server for EAs or streams to
80 returns as xattrs */
81 if (size > MAX_EA_VALUE_SIZE) {
82 cifs_dbg(FYI, "size of EA value too large\n");
83 rc = -EOPNOTSUPP;
84 goto out;
85 }
86
87 switch (handler->flags) {
88 case XATTR_USER:
89 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
90 goto out;
91
92 if (pTcon->ses->server->ops->set_EA)
93 rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
94 full_path, name, value, (__u16)size,
95 cifs_sb->local_nls, cifs_sb);
96 break;
97
98 case XATTR_CIFS_ACL: {
99 struct cifs_ntsd *pacl;
100
101 if (!value)
102 goto out;
103 pacl = kmalloc(size, GFP_KERNEL);
104 if (!pacl) {
105 rc = -ENOMEM;
106 } else {
107 memcpy(pacl, value, size);
108 if (value &&
109 pTcon->ses->server->ops->set_acl)
110 rc = pTcon->ses->server->ops->set_acl(pacl,
111 size, inode,
112 full_path, CIFS_ACL_DACL);
113 else
114 rc = -EOPNOTSUPP;
115 if (rc == 0) /* force revalidate of the inode */
116 CIFS_I(inode)->time = 0;
117 kfree(pacl);
118 }
119 break;
120 }
121
122 case XATTR_ACL_ACCESS:
123 #ifdef CONFIG_CIFS_POSIX
124 if (!value)
125 goto out;
126 if (sb->s_flags & SB_POSIXACL)
127 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
128 value, (const int)size,
129 ACL_TYPE_ACCESS, cifs_sb->local_nls,
130 cifs_remap(cifs_sb));
131 #endif /* CONFIG_CIFS_POSIX */
132 break;
133
134 case XATTR_ACL_DEFAULT:
135 #ifdef CONFIG_CIFS_POSIX
136 if (!value)
137 goto out;
138 if (sb->s_flags & SB_POSIXACL)
139 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
140 value, (const int)size,
141 ACL_TYPE_DEFAULT, cifs_sb->local_nls,
142 cifs_remap(cifs_sb));
143 #endif /* CONFIG_CIFS_POSIX */
144 break;
145 }
146
147 out:
148 kfree(full_path);
149 free_xid(xid);
150 cifs_put_tlink(tlink);
151 return rc;
152 }
153
cifs_attrib_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)154 static int cifs_attrib_get(struct dentry *dentry,
155 struct inode *inode, void *value,
156 size_t size)
157 {
158 ssize_t rc;
159 __u32 *pattribute;
160
161 rc = cifs_revalidate_dentry_attr(dentry);
162
163 if (rc)
164 return rc;
165
166 if ((value == NULL) || (size == 0))
167 return sizeof(__u32);
168 else if (size < sizeof(__u32))
169 return -ERANGE;
170
171 /* return dos attributes as pseudo xattr */
172 pattribute = (__u32 *)value;
173 *pattribute = CIFS_I(inode)->cifsAttrs;
174
175 return sizeof(__u32);
176 }
177
cifs_creation_time_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)178 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
179 void *value, size_t size)
180 {
181 ssize_t rc;
182 __u64 * pcreatetime;
183
184 rc = cifs_revalidate_dentry_attr(dentry);
185 if (rc)
186 return rc;
187
188 if ((value == NULL) || (size == 0))
189 return sizeof(__u64);
190 else if (size < sizeof(__u64))
191 return -ERANGE;
192
193 /* return dos attributes as pseudo xattr */
194 pcreatetime = (__u64 *)value;
195 *pcreatetime = CIFS_I(inode)->createtime;
196 return sizeof(__u64);
197 }
198
199
cifs_xattr_get(const struct xattr_handler * handler,struct dentry * dentry,struct inode * inode,const char * name,void * value,size_t size)200 static int cifs_xattr_get(const struct xattr_handler *handler,
201 struct dentry *dentry, struct inode *inode,
202 const char *name, void *value, size_t size)
203 {
204 ssize_t rc = -EOPNOTSUPP;
205 unsigned int xid;
206 struct super_block *sb = dentry->d_sb;
207 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
208 struct tcon_link *tlink;
209 struct cifs_tcon *pTcon;
210 char *full_path;
211
212 tlink = cifs_sb_tlink(cifs_sb);
213 if (IS_ERR(tlink))
214 return PTR_ERR(tlink);
215 pTcon = tlink_tcon(tlink);
216
217 xid = get_xid();
218
219 full_path = build_path_from_dentry(dentry);
220 if (full_path == NULL) {
221 rc = -ENOMEM;
222 goto out;
223 }
224
225 /* return alt name if available as pseudo attr */
226 switch (handler->flags) {
227 case XATTR_USER:
228 cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
229 if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
230 (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
231 rc = cifs_attrib_get(dentry, inode, value, size);
232 break;
233 } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
234 (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
235 rc = cifs_creation_time_get(dentry, inode, value, size);
236 break;
237 }
238
239 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
240 goto out;
241
242 if (pTcon->ses->server->ops->query_all_EAs)
243 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
244 full_path, name, value, size, cifs_sb);
245 break;
246
247 case XATTR_CIFS_ACL: {
248 u32 acllen;
249 struct cifs_ntsd *pacl;
250
251 if (pTcon->ses->server->ops->get_acl == NULL)
252 goto out; /* rc already EOPNOTSUPP */
253
254 pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
255 inode, full_path, &acllen);
256 if (IS_ERR(pacl)) {
257 rc = PTR_ERR(pacl);
258 cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
259 __func__, rc);
260 } else {
261 if (value) {
262 if (acllen > size)
263 acllen = -ERANGE;
264 else
265 memcpy(value, pacl, acllen);
266 }
267 rc = acllen;
268 kfree(pacl);
269 }
270 break;
271 }
272
273 case XATTR_ACL_ACCESS:
274 #ifdef CONFIG_CIFS_POSIX
275 if (sb->s_flags & SB_POSIXACL)
276 rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
277 value, size, ACL_TYPE_ACCESS,
278 cifs_sb->local_nls,
279 cifs_remap(cifs_sb));
280 #endif /* CONFIG_CIFS_POSIX */
281 break;
282
283 case XATTR_ACL_DEFAULT:
284 #ifdef CONFIG_CIFS_POSIX
285 if (sb->s_flags & SB_POSIXACL)
286 rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
287 value, size, ACL_TYPE_DEFAULT,
288 cifs_sb->local_nls,
289 cifs_remap(cifs_sb));
290 #endif /* CONFIG_CIFS_POSIX */
291 break;
292 }
293
294 /* We could add an additional check for streams ie
295 if proc/fs/cifs/streamstoxattr is set then
296 search server for EAs or streams to
297 returns as xattrs */
298
299 if (rc == -EINVAL)
300 rc = -EOPNOTSUPP;
301
302 out:
303 kfree(full_path);
304 free_xid(xid);
305 cifs_put_tlink(tlink);
306 return rc;
307 }
308
cifs_listxattr(struct dentry * direntry,char * data,size_t buf_size)309 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
310 {
311 ssize_t rc = -EOPNOTSUPP;
312 unsigned int xid;
313 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
314 struct tcon_link *tlink;
315 struct cifs_tcon *pTcon;
316 char *full_path;
317
318 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
319 return -EOPNOTSUPP;
320
321 tlink = cifs_sb_tlink(cifs_sb);
322 if (IS_ERR(tlink))
323 return PTR_ERR(tlink);
324 pTcon = tlink_tcon(tlink);
325
326 xid = get_xid();
327
328 full_path = build_path_from_dentry(direntry);
329 if (full_path == NULL) {
330 rc = -ENOMEM;
331 goto list_ea_exit;
332 }
333 /* return dos attributes as pseudo xattr */
334 /* return alt name if available as pseudo attr */
335
336 /* if proc/fs/cifs/streamstoxattr is set then
337 search server for EAs or streams to
338 returns as xattrs */
339
340 if (pTcon->ses->server->ops->query_all_EAs)
341 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
342 full_path, NULL, data, buf_size, cifs_sb);
343 list_ea_exit:
344 kfree(full_path);
345 free_xid(xid);
346 cifs_put_tlink(tlink);
347 return rc;
348 }
349
350 static const struct xattr_handler cifs_user_xattr_handler = {
351 .prefix = XATTR_USER_PREFIX,
352 .flags = XATTR_USER,
353 .get = cifs_xattr_get,
354 .set = cifs_xattr_set,
355 };
356
357 /* os2.* attributes are treated like user.* attributes */
358 static const struct xattr_handler cifs_os2_xattr_handler = {
359 .prefix = XATTR_OS2_PREFIX,
360 .flags = XATTR_USER,
361 .get = cifs_xattr_get,
362 .set = cifs_xattr_set,
363 };
364
365 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
366 .name = CIFS_XATTR_CIFS_ACL,
367 .flags = XATTR_CIFS_ACL,
368 .get = cifs_xattr_get,
369 .set = cifs_xattr_set,
370 };
371
372 /*
373 * Although this is just an alias for the above, need to move away from
374 * confusing users and using the 20 year old term 'cifs' when it is no
375 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
376 * SMB3 and later are highly secure.
377 */
378 static const struct xattr_handler smb3_acl_xattr_handler = {
379 .name = SMB3_XATTR_CIFS_ACL,
380 .flags = XATTR_CIFS_ACL,
381 .get = cifs_xattr_get,
382 .set = cifs_xattr_set,
383 };
384
385 static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
386 .name = XATTR_NAME_POSIX_ACL_ACCESS,
387 .flags = XATTR_ACL_ACCESS,
388 .get = cifs_xattr_get,
389 .set = cifs_xattr_set,
390 };
391
392 static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
393 .name = XATTR_NAME_POSIX_ACL_DEFAULT,
394 .flags = XATTR_ACL_DEFAULT,
395 .get = cifs_xattr_get,
396 .set = cifs_xattr_set,
397 };
398
399 const struct xattr_handler *cifs_xattr_handlers[] = {
400 &cifs_user_xattr_handler,
401 &cifs_os2_xattr_handler,
402 &cifs_cifs_acl_xattr_handler,
403 &smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
404 &cifs_posix_acl_access_xattr_handler,
405 &cifs_posix_acl_default_xattr_handler,
406 NULL
407 };
408
