xref: /kernel/linux/linux-5.10/fs/cifs/xattr.c (revision 8c2ecf20)
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" /* DACL only */
36#define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
37#define CIFS_XATTR_ATTRIB "cifs.dosattrib"  /* full name: user.cifs.dosattrib */
38#define CIFS_XATTR_CREATETIME "cifs.creationtime"  /* user.cifs.creationtime */
39/*
40 * Although these three are just aliases for the above, need to move away from
41 * confusing users and using the 20+ year old term 'cifs' when it is no longer
42 * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
43 */
44#define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
45#define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
46#define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
47#define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
48/* BB need to add server (Samba e.g) support for security and trusted prefix */
49
50enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
51	XATTR_CIFS_NTSD };
52
53static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
54			   struct inode *inode, char *full_path,
55			   const void *value, size_t size)
56{
57	ssize_t rc = -EOPNOTSUPP;
58	__u32 *pattrib = (__u32 *)value;
59	__u32 attrib;
60	FILE_BASIC_INFO info_buf;
61
62	if ((value == NULL) || (size != sizeof(__u32)))
63		return -ERANGE;
64
65	memset(&info_buf, 0, sizeof(info_buf));
66	attrib = *pattrib;
67	info_buf.Attributes = cpu_to_le32(attrib);
68	if (pTcon->ses->server->ops->set_file_info)
69		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
70				&info_buf, xid);
71	if (rc == 0)
72		CIFS_I(inode)->cifsAttrs = attrib;
73
74	return rc;
75}
76
77static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
78				  struct inode *inode, char *full_path,
79				  const void *value, size_t size)
80{
81	ssize_t rc = -EOPNOTSUPP;
82	__u64 *pcreation_time = (__u64 *)value;
83	__u64 creation_time;
84	FILE_BASIC_INFO info_buf;
85
86	if ((value == NULL) || (size != sizeof(__u64)))
87		return -ERANGE;
88
89	memset(&info_buf, 0, sizeof(info_buf));
90	creation_time = *pcreation_time;
91	info_buf.CreationTime = cpu_to_le64(creation_time);
92	if (pTcon->ses->server->ops->set_file_info)
93		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
94				&info_buf, xid);
95	if (rc == 0)
96		CIFS_I(inode)->createtime = creation_time;
97
98	return rc;
99}
100
101static int cifs_xattr_set(const struct xattr_handler *handler,
102			  struct dentry *dentry, struct inode *inode,
103			  const char *name, const void *value,
104			  size_t size, int flags)
105{
106	int rc = -EOPNOTSUPP;
107	unsigned int xid;
108	struct super_block *sb = dentry->d_sb;
109	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
110	struct tcon_link *tlink;
111	struct cifs_tcon *pTcon;
112	char *full_path;
113
114	tlink = cifs_sb_tlink(cifs_sb);
115	if (IS_ERR(tlink))
116		return PTR_ERR(tlink);
117	pTcon = tlink_tcon(tlink);
118
119	xid = get_xid();
120
121	full_path = build_path_from_dentry(dentry);
122	if (full_path == NULL) {
123		rc = -ENOMEM;
124		goto out;
125	}
126	/* return dos attributes as pseudo xattr */
127	/* return alt name if available as pseudo attr */
128
129	/* if proc/fs/cifs/streamstoxattr is set then
130		search server for EAs or streams to
131		returns as xattrs */
132	if (size > MAX_EA_VALUE_SIZE) {
133		cifs_dbg(FYI, "size of EA value too large\n");
134		rc = -EOPNOTSUPP;
135		goto out;
136	}
137
138	switch (handler->flags) {
139	case XATTR_USER:
140		cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
141		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
142		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
143			rc = cifs_attrib_set(xid, pTcon, inode, full_path,
144					value, size);
145			if (rc == 0) /* force revalidate of the inode */
146				CIFS_I(inode)->time = 0;
147			break;
148		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
149			   (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
150			rc = cifs_creation_time_set(xid, pTcon, inode,
151					full_path, value, size);
152			if (rc == 0) /* force revalidate of the inode */
153				CIFS_I(inode)->time = 0;
154			break;
155		}
156
157		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
158			goto out;
159
160		if (pTcon->ses->server->ops->set_EA) {
161			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
162				full_path, name, value, (__u16)size,
163				cifs_sb->local_nls, cifs_sb);
164			if (rc == 0)
165				inode_set_ctime_current(inode);
166		}
167		break;
168
169	case XATTR_CIFS_ACL:
170	case XATTR_CIFS_NTSD: {
171		struct cifs_ntsd *pacl;
172
173		if (!value)
174			goto out;
175		pacl = kmalloc(size, GFP_KERNEL);
176		if (!pacl) {
177			rc = -ENOMEM;
178		} else {
179			memcpy(pacl, value, size);
180			if (value &&
181			    pTcon->ses->server->ops->set_acl) {
182				rc = 0;
183				if (handler->flags == XATTR_CIFS_NTSD) {
184					/* set owner and DACL */
185					rc = pTcon->ses->server->ops->set_acl(
186							pacl, size, inode,
187							full_path,
188							CIFS_ACL_OWNER);
189				}
190				if (rc == 0) {
191					/* set DACL */
192					rc = pTcon->ses->server->ops->set_acl(
193							pacl, size, inode,
194							full_path,
195							CIFS_ACL_DACL);
196				}
197			} else {
198				rc = -EOPNOTSUPP;
199			}
200			if (rc == 0) /* force revalidate of the inode */
201				CIFS_I(inode)->time = 0;
202			kfree(pacl);
203		}
204		break;
205	}
206
207	case XATTR_ACL_ACCESS:
208#ifdef CONFIG_CIFS_POSIX
209		if (!value)
210			goto out;
211		if (sb->s_flags & SB_POSIXACL)
212			rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
213				value, (const int)size,
214				ACL_TYPE_ACCESS, cifs_sb->local_nls,
215				cifs_remap(cifs_sb));
216#endif  /* CONFIG_CIFS_POSIX */
217		break;
218
219	case XATTR_ACL_DEFAULT:
220#ifdef CONFIG_CIFS_POSIX
221		if (!value)
222			goto out;
223		if (sb->s_flags & SB_POSIXACL)
224			rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
225				value, (const int)size,
226				ACL_TYPE_DEFAULT, cifs_sb->local_nls,
227				cifs_remap(cifs_sb));
228#endif  /* CONFIG_CIFS_POSIX */
229		break;
230	}
231
232out:
233	kfree(full_path);
234	free_xid(xid);
235	cifs_put_tlink(tlink);
236	return rc;
237}
238
239static int cifs_attrib_get(struct dentry *dentry,
240			   struct inode *inode, void *value,
241			   size_t size)
242{
243	ssize_t rc;
244	__u32 *pattribute;
245
246	rc = cifs_revalidate_dentry_attr(dentry);
247
248	if (rc)
249		return rc;
250
251	if ((value == NULL) || (size == 0))
252		return sizeof(__u32);
253	else if (size < sizeof(__u32))
254		return -ERANGE;
255
256	/* return dos attributes as pseudo xattr */
257	pattribute = (__u32 *)value;
258	*pattribute = CIFS_I(inode)->cifsAttrs;
259
260	return sizeof(__u32);
261}
262
263static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
264				  void *value, size_t size)
265{
266	ssize_t rc;
267	__u64 *pcreatetime;
268
269	rc = cifs_revalidate_dentry_attr(dentry);
270	if (rc)
271		return rc;
272
273	if ((value == NULL) || (size == 0))
274		return sizeof(__u64);
275	else if (size < sizeof(__u64))
276		return -ERANGE;
277
278	/* return dos attributes as pseudo xattr */
279	pcreatetime = (__u64 *)value;
280	*pcreatetime = CIFS_I(inode)->createtime;
281	return sizeof(__u64);
282}
283
284
285static int cifs_xattr_get(const struct xattr_handler *handler,
286			  struct dentry *dentry, struct inode *inode,
287			  const char *name, void *value, size_t size)
288{
289	ssize_t rc = -EOPNOTSUPP;
290	unsigned int xid;
291	struct super_block *sb = dentry->d_sb;
292	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
293	struct tcon_link *tlink;
294	struct cifs_tcon *pTcon;
295	char *full_path;
296
297	tlink = cifs_sb_tlink(cifs_sb);
298	if (IS_ERR(tlink))
299		return PTR_ERR(tlink);
300	pTcon = tlink_tcon(tlink);
301
302	xid = get_xid();
303
304	full_path = build_path_from_dentry(dentry);
305	if (full_path == NULL) {
306		rc = -ENOMEM;
307		goto out;
308	}
309
310	/* return alt name if available as pseudo attr */
311	switch (handler->flags) {
312	case XATTR_USER:
313		cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
314		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
315		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
316			rc = cifs_attrib_get(dentry, inode, value, size);
317			break;
318		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
319		    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
320			rc = cifs_creation_time_get(dentry, inode, value, size);
321			break;
322		}
323
324		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
325			goto out;
326
327		if (pTcon->ses->server->ops->query_all_EAs)
328			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
329				full_path, name, value, size, cifs_sb);
330		break;
331
332	case XATTR_CIFS_ACL:
333	case XATTR_CIFS_NTSD: {
334		/* the whole ntsd is fetched regardless */
335		u32 acllen;
336		struct cifs_ntsd *pacl;
337
338		if (pTcon->ses->server->ops->get_acl == NULL)
339			goto out; /* rc already EOPNOTSUPP */
340
341		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
342				inode, full_path, &acllen);
343		if (IS_ERR(pacl)) {
344			rc = PTR_ERR(pacl);
345			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
346				 __func__, rc);
347		} else {
348			if (value) {
349				if (acllen > size)
350					acllen = -ERANGE;
351				else
352					memcpy(value, pacl, acllen);
353			}
354			rc = acllen;
355			kfree(pacl);
356		}
357		break;
358	}
359
360	case XATTR_ACL_ACCESS:
361#ifdef CONFIG_CIFS_POSIX
362		if (sb->s_flags & SB_POSIXACL)
363			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
364				value, size, ACL_TYPE_ACCESS,
365				cifs_sb->local_nls,
366				cifs_remap(cifs_sb));
367#endif  /* CONFIG_CIFS_POSIX */
368		break;
369
370	case XATTR_ACL_DEFAULT:
371#ifdef CONFIG_CIFS_POSIX
372		if (sb->s_flags & SB_POSIXACL)
373			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
374				value, size, ACL_TYPE_DEFAULT,
375				cifs_sb->local_nls,
376				cifs_remap(cifs_sb));
377#endif  /* CONFIG_CIFS_POSIX */
378		break;
379	}
380
381	/* We could add an additional check for streams ie
382	    if proc/fs/cifs/streamstoxattr is set then
383		search server for EAs or streams to
384		returns as xattrs */
385
386	if (rc == -EINVAL)
387		rc = -EOPNOTSUPP;
388
389out:
390	kfree(full_path);
391	free_xid(xid);
392	cifs_put_tlink(tlink);
393	return rc;
394}
395
396ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
397{
398	ssize_t rc = -EOPNOTSUPP;
399	unsigned int xid;
400	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
401	struct tcon_link *tlink;
402	struct cifs_tcon *pTcon;
403	char *full_path;
404
405	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
406		return -EOPNOTSUPP;
407
408	tlink = cifs_sb_tlink(cifs_sb);
409	if (IS_ERR(tlink))
410		return PTR_ERR(tlink);
411	pTcon = tlink_tcon(tlink);
412
413	xid = get_xid();
414
415	full_path = build_path_from_dentry(direntry);
416	if (full_path == NULL) {
417		rc = -ENOMEM;
418		goto list_ea_exit;
419	}
420	/* return dos attributes as pseudo xattr */
421	/* return alt name if available as pseudo attr */
422
423	/* if proc/fs/cifs/streamstoxattr is set then
424		search server for EAs or streams to
425		returns as xattrs */
426
427	if (pTcon->ses->server->ops->query_all_EAs)
428		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
429				full_path, NULL, data, buf_size, cifs_sb);
430list_ea_exit:
431	kfree(full_path);
432	free_xid(xid);
433	cifs_put_tlink(tlink);
434	return rc;
435}
436
437static const struct xattr_handler cifs_user_xattr_handler = {
438	.prefix = XATTR_USER_PREFIX,
439	.flags = XATTR_USER,
440	.get = cifs_xattr_get,
441	.set = cifs_xattr_set,
442};
443
444/* os2.* attributes are treated like user.* attributes */
445static const struct xattr_handler cifs_os2_xattr_handler = {
446	.prefix = XATTR_OS2_PREFIX,
447	.flags = XATTR_USER,
448	.get = cifs_xattr_get,
449	.set = cifs_xattr_set,
450};
451
452static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
453	.name = CIFS_XATTR_CIFS_ACL,
454	.flags = XATTR_CIFS_ACL,
455	.get = cifs_xattr_get,
456	.set = cifs_xattr_set,
457};
458
459/*
460 * Although this is just an alias for the above, need to move away from
461 * confusing users and using the 20 year old term 'cifs' when it is no
462 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
463 * SMB3 and later are highly secure.
464 */
465static const struct xattr_handler smb3_acl_xattr_handler = {
466	.name = SMB3_XATTR_CIFS_ACL,
467	.flags = XATTR_CIFS_ACL,
468	.get = cifs_xattr_get,
469	.set = cifs_xattr_set,
470};
471
472static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
473	.name = CIFS_XATTR_CIFS_NTSD,
474	.flags = XATTR_CIFS_NTSD,
475	.get = cifs_xattr_get,
476	.set = cifs_xattr_set,
477};
478
479/*
480 * Although this is just an alias for the above, need to move away from
481 * confusing users and using the 20 year old term 'cifs' when it is no
482 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
483 * SMB3 and later are highly secure.
484 */
485static const struct xattr_handler smb3_ntsd_xattr_handler = {
486	.name = SMB3_XATTR_CIFS_NTSD,
487	.flags = XATTR_CIFS_NTSD,
488	.get = cifs_xattr_get,
489	.set = cifs_xattr_set,
490};
491
492static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
493	.name = XATTR_NAME_POSIX_ACL_ACCESS,
494	.flags = XATTR_ACL_ACCESS,
495	.get = cifs_xattr_get,
496	.set = cifs_xattr_set,
497};
498
499static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
500	.name = XATTR_NAME_POSIX_ACL_DEFAULT,
501	.flags = XATTR_ACL_DEFAULT,
502	.get = cifs_xattr_get,
503	.set = cifs_xattr_set,
504};
505
506const struct xattr_handler *cifs_xattr_handlers[] = {
507	&cifs_user_xattr_handler,
508	&cifs_os2_xattr_handler,
509	&cifs_cifs_acl_xattr_handler,
510	&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
511	&cifs_cifs_ntsd_xattr_handler,
512	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
513	&cifs_posix_acl_access_xattr_handler,
514	&cifs_posix_acl_default_xattr_handler,
515	NULL
516};
517