summaryrefslogtreecommitdiff
path: root/fs/cifs/xattr.c
blob: 4ad5531686d81aa4e9395f58ceb04be13520b5a2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
// SPDX-License-Identifier: LGPL-2.1
/*
 *
 *   Copyright (c) International Business Machines  Corp., 2003, 2007
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 */

#include <linux/fs.h>
#include <linux/posix_acl_xattr.h>
#include <linux/slab.h>
#include <linux/xattr.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "cifs_unicode.h"
#include "cifs_ioctl.h"

#define MAX_EA_VALUE_SIZE CIFSMaxBufSize
#define CIFS_XATTR_CIFS_ACL "system.cifs_acl" /* DACL only */
#define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
#define CIFS_XATTR_CIFS_NTSD_FULL "system.cifs_ntsd_full" /* owner/DACL/SACL */
#define CIFS_XATTR_ATTRIB "cifs.dosattrib"  /* full name: user.cifs.dosattrib */
#define CIFS_XATTR_CREATETIME "cifs.creationtime"  /* user.cifs.creationtime */
/*
 * Although these three are just aliases for the above, need to move away from
 * confusing users and using the 20+ year old term 'cifs' when it is no longer
 * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
 */
#define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
#define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
#define SMB3_XATTR_CIFS_NTSD_FULL "system.smb3_ntsd_full" /* owner/DACL/SACL */
#define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
#define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
/* BB need to add server (Samba e.g) support for security and trusted prefix */

enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
	XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };

static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
			   struct inode *inode, const char *full_path,
			   const void *value, size_t size)
{
	ssize_t rc = -EOPNOTSUPP;
	__u32 *pattrib = (__u32 *)value;
	__u32 attrib;
	FILE_BASIC_INFO info_buf;

	if ((value == NULL) || (size != sizeof(__u32)))
		return -ERANGE;

	memset(&info_buf, 0, sizeof(info_buf));
	attrib = *pattrib;
	info_buf.Attributes = cpu_to_le32(attrib);
	if (pTcon->ses->server->ops->set_file_info)
		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
				&info_buf, xid);
	if (rc == 0)
		CIFS_I(inode)->cifsAttrs = attrib;

	return rc;
}

static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
				  struct inode *inode, const char *full_path,
				  const void *value, size_t size)
{
	ssize_t rc = -EOPNOTSUPP;
	__u64 *pcreation_time = (__u64 *)value;
	__u64 creation_time;
	FILE_BASIC_INFO info_buf;

	if ((value == NULL) || (size != sizeof(__u64)))
		return -ERANGE;

	memset(&info_buf, 0, sizeof(info_buf));
	creation_time = *pcreation_time;
	info_buf.CreationTime = cpu_to_le64(creation_time);
	if (pTcon->ses->server->ops->set_file_info)
		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
				&info_buf, xid);
	if (rc == 0)
		CIFS_I(inode)->createtime = creation_time;

	return rc;
}

static int cifs_xattr_set(const struct xattr_handler *handler,
			  struct mnt_idmap *idmap,
			  struct dentry *dentry, struct inode *inode,
			  const char *name, const void *value,
			  size_t size, int flags)
{
	int rc = -EOPNOTSUPP;
	unsigned int xid;
	struct super_block *sb = dentry->d_sb;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct tcon_link *tlink;
	struct cifs_tcon *pTcon;
	const char *full_path;
	void *page;

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	pTcon = tlink_tcon(tlink);

	xid = get_xid();
	page = alloc_dentry_path();

	full_path = build_path_from_dentry(dentry, page);
	if (IS_ERR(full_path)) {
		rc = PTR_ERR(full_path);
		goto out;
	}
	/* return dos attributes as pseudo xattr */
	/* return alt name if available as pseudo attr */

	/* if proc/fs/cifs/streamstoxattr is set then
		search server for EAs or streams to
		returns as xattrs */
	if (size > MAX_EA_VALUE_SIZE) {
		cifs_dbg(FYI, "size of EA value too large\n");
		rc = -EOPNOTSUPP;
		goto out;
	}

	switch (handler->flags) {
	case XATTR_USER:
		cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
			rc = cifs_attrib_set(xid, pTcon, inode, full_path,
					value, size);
			if (rc == 0) /* force revalidate of the inode */
				CIFS_I(inode)->time = 0;
			break;
		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
			   (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
			rc = cifs_creation_time_set(xid, pTcon, inode,
					full_path, value, size);
			if (rc == 0) /* force revalidate of the inode */
				CIFS_I(inode)->time = 0;
			break;
		}

		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
			goto out;

		if (pTcon->ses->server->ops->set_EA)
			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
				full_path, name, value, (__u16)size,
				cifs_sb->local_nls, cifs_sb);
		break;

	case XATTR_CIFS_ACL:
	case XATTR_CIFS_NTSD:
	case XATTR_CIFS_NTSD_FULL: {
		struct cifs_ntsd *pacl;

		if (!value)
			goto out;
		pacl = kmalloc(size, GFP_KERNEL);
		if (!pacl) {
			rc = -ENOMEM;
		} else {
			memcpy(pacl, value, size);
			if (pTcon->ses->server->ops->set_acl) {
				int aclflags = 0;
				rc = 0;

				switch (handler->flags) {
				case XATTR_CIFS_NTSD_FULL:
					aclflags = (CIFS_ACL_OWNER |
						    CIFS_ACL_GROUP |
						    CIFS_ACL_DACL |
						    CIFS_ACL_SACL);
					break;
				case XATTR_CIFS_NTSD:
					aclflags = (CIFS_ACL_OWNER |
						    CIFS_ACL_GROUP |
						    CIFS_ACL_DACL);
					break;
				case XATTR_CIFS_ACL:
				default:
					aclflags = CIFS_ACL_DACL;
				}

				rc = pTcon->ses->server->ops->set_acl(pacl,
					size, inode, full_path, aclflags);
			} else {
				rc = -EOPNOTSUPP;
			}
			if (rc == 0) /* force revalidate of the inode */
				CIFS_I(inode)->time = 0;
			kfree(pacl);
		}
		break;
	}
	}

out:
	free_dentry_path(page);
	free_xid(xid);
	cifs_put_tlink(tlink);
	return rc;
}

static int cifs_attrib_get(struct dentry *dentry,
			   struct inode *inode, void *value,
			   size_t size)
{
	ssize_t rc;
	__u32 *pattribute;

	rc = cifs_revalidate_dentry_attr(dentry);

	if (rc)
		return rc;

	if ((value == NULL) || (size == 0))
		return sizeof(__u32);
	else if (size < sizeof(__u32))
		return -ERANGE;

	/* return dos attributes as pseudo xattr */
	pattribute = (__u32 *)value;
	*pattribute = CIFS_I(inode)->cifsAttrs;

	return sizeof(__u32);
}

static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
				  void *value, size_t size)
{
	ssize_t rc;
	__u64 *pcreatetime;

	rc = cifs_revalidate_dentry_attr(dentry);
	if (rc)
		return rc;

	if ((value == NULL) || (size == 0))
		return sizeof(__u64);
	else if (size < sizeof(__u64))
		return -ERANGE;

	/* return dos attributes as pseudo xattr */
	pcreatetime = (__u64 *)value;
	*pcreatetime = CIFS_I(inode)->createtime;
	return sizeof(__u64);
}


static int cifs_xattr_get(const struct xattr_handler *handler,
			  struct dentry *dentry, struct inode *inode,
			  const char *name, void *value, size_t size)
{
	ssize_t rc = -EOPNOTSUPP;
	unsigned int xid;
	struct super_block *sb = dentry->d_sb;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct tcon_link *tlink;
	struct cifs_tcon *pTcon;
	const char *full_path;
	void *page;

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	pTcon = tlink_tcon(tlink);

	xid = get_xid();
	page = alloc_dentry_path();

	full_path = build_path_from_dentry(dentry, page);
	if (IS_ERR(full_path)) {
		rc = PTR_ERR(full_path);
		goto out;
	}

	/* return alt name if available as pseudo attr */
	switch (handler->flags) {
	case XATTR_USER:
		cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
			rc = cifs_attrib_get(dentry, inode, value, size);
			break;
		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
		    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
			rc = cifs_creation_time_get(dentry, inode, value, size);
			break;
		}

		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
			goto out;

		if (pTcon->ses->server->ops->query_all_EAs)
			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
				full_path, name, value, size, cifs_sb);
		break;

	case XATTR_CIFS_ACL:
	case XATTR_CIFS_NTSD:
	case XATTR_CIFS_NTSD_FULL: {
		/*
		 * fetch owner, DACL, and SACL if asked for full descriptor,
		 * fetch owner and DACL otherwise
		 */
		u32 acllen, extra_info;
		struct cifs_ntsd *pacl;

		if (pTcon->ses->server->ops->get_acl == NULL)
			goto out; /* rc already EOPNOTSUPP */

		if (handler->flags == XATTR_CIFS_NTSD_FULL) {
			extra_info = SACL_SECINFO;
		} else {
			extra_info = 0;
		}
		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
				inode, full_path, &acllen, extra_info);
		if (IS_ERR(pacl)) {
			rc = PTR_ERR(pacl);
			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
				 __func__, rc);
		} else {
			if (value) {
				if (acllen > size)
					acllen = -ERANGE;
				else
					memcpy(value, pacl, acllen);
			}
			rc = acllen;
			kfree(pacl);
		}
		break;
	}
	}

	/* We could add an additional check for streams ie
	    if proc/fs/cifs/streamstoxattr is set then
		search server for EAs or streams to
		returns as xattrs */

	if (rc == -EINVAL)
		rc = -EOPNOTSUPP;

out:
	free_dentry_path(page);
	free_xid(xid);
	cifs_put_tlink(tlink);
	return rc;
}

ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
{
	ssize_t rc = -EOPNOTSUPP;
	unsigned int xid;
	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
	struct tcon_link *tlink;
	struct cifs_tcon *pTcon;
	const char *full_path;
	void *page;

	if (unlikely(cifs_forced_shutdown(cifs_sb)))
		return -EIO;

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
		return -EOPNOTSUPP;

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	pTcon = tlink_tcon(tlink);

	xid = get_xid();
	page = alloc_dentry_path();

	full_path = build_path_from_dentry(direntry, page);
	if (IS_ERR(full_path)) {
		rc = PTR_ERR(full_path);
		goto list_ea_exit;
	}
	/* return dos attributes as pseudo xattr */
	/* return alt name if available as pseudo attr */

	/* if proc/fs/cifs/streamstoxattr is set then
		search server for EAs or streams to
		returns as xattrs */

	if (pTcon->ses->server->ops->query_all_EAs)
		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
				full_path, NULL, data, buf_size, cifs_sb);
list_ea_exit:
	free_dentry_path(page);
	free_xid(xid);
	cifs_put_tlink(tlink);
	return rc;
}

static const struct xattr_handler cifs_user_xattr_handler = {
	.prefix = XATTR_USER_PREFIX,
	.flags = XATTR_USER,
	.get = cifs_xattr_get,
	.set = cifs_xattr_set,
};

/* os2.* attributes are treated like user.* attributes */
static const struct xattr_handler cifs_os2_xattr_handler = {
	.prefix = XATTR_OS2_PREFIX,
	.flags = XATTR_USER,
	.get = cifs_xattr_get,
	.set = cifs_xattr_set,
};

static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
	.name = CIFS_XATTR_CIFS_ACL,
	.flags = XATTR_CIFS_ACL,
	.get = cifs_xattr_get,
	.set = cifs_xattr_set,
};

/*
 * Although this is just an alias for the above, need to move away from
 * confusing users and using the 20 year old term 'cifs' when it is no
 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 * SMB3 and later are highly secure.
 */
static const struct xattr_handler smb3_acl_xattr_handler = {
	.name = SMB3_XATTR_CIFS_ACL,
	.flags = XATTR_CIFS_ACL,
	.get = cifs_xattr_get,
	.set = cifs_xattr_set,
};

static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
	.name = CIFS_XATTR_CIFS_NTSD,
	.flags = XATTR_CIFS_NTSD,
	.get = cifs_xattr_get,
	.set = cifs_xattr_set,
};

/*
 * Although this is just an alias for the above, need to move away from
 * confusing users and using the 20 year old term 'cifs' when it is no
 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 * SMB3 and later are highly secure.
 */
static const struct xattr_handler smb3_ntsd_xattr_handler = {
	.name = SMB3_XATTR_CIFS_NTSD,
	.flags = XATTR_CIFS_NTSD,
	.get = cifs_xattr_get,
	.set = cifs_xattr_set,
};

static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
	.name = CIFS_XATTR_CIFS_NTSD_FULL,
	.flags = XATTR_CIFS_NTSD_FULL,
	.get = cifs_xattr_get,
	.set = cifs_xattr_set,
};

/*
 * Although this is just an alias for the above, need to move away from
 * confusing users and using the 20 year old term 'cifs' when it is no
 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 * SMB3 and later are highly secure.
 */
static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
	.name = SMB3_XATTR_CIFS_NTSD_FULL,
	.flags = XATTR_CIFS_NTSD_FULL,
	.get = cifs_xattr_get,
	.set = cifs_xattr_set,
};

const struct xattr_handler *cifs_xattr_handlers[] = {
	&cifs_user_xattr_handler,
	&cifs_os2_xattr_handler,
	&cifs_cifs_acl_xattr_handler,
	&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
	&cifs_cifs_ntsd_xattr_handler,
	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
	&cifs_cifs_ntsd_full_xattr_handler,
	&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
	NULL
};