1// SPDX-License-Identifier: LGPL-2.1
2/*
3 *
4 *   Copyright (c) International Business Machines  Corp., 2003, 2007
5 *   Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 */
8
9#include <linux/fs.h>
10#include <linux/posix_acl_xattr.h>
11#include <linux/slab.h>
12#include <linux/xattr.h>
13#include "cifsfs.h"
14#include "cifspdu.h"
15#include "cifsglob.h"
16#include "cifsproto.h"
17#include "cifs_debug.h"
18#include "cifs_fs_sb.h"
19#include "cifs_unicode.h"
20#include "cifs_ioctl.h"
21
22#define MAX_EA_VALUE_SIZE CIFSMaxBufSize
23#define CIFS_XATTR_CIFS_ACL "system.cifs_acl" /* DACL only */
24#define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
25#define CIFS_XATTR_CIFS_NTSD_FULL "system.cifs_ntsd_full" /* owner/DACL/SACL */
26#define CIFS_XATTR_ATTRIB "cifs.dosattrib"  /* full name: user.cifs.dosattrib */
27#define CIFS_XATTR_CREATETIME "cifs.creationtime"  /* user.cifs.creationtime */
28/*
29 * Although these three are just aliases for the above, need to move away from
30 * confusing users and using the 20+ year old term 'cifs' when it is no longer
31 * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
32 */
33#define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
34#define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
35#define SMB3_XATTR_CIFS_NTSD_FULL "system.smb3_ntsd_full" /* owner/DACL/SACL */
36#define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
37#define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
38/* BB need to add server (Samba e.g) support for security and trusted prefix */
39
40enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
41	XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };
42
43static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
44			   struct inode *inode, const char *full_path,
45			   const void *value, size_t size)
46{
47	ssize_t rc = -EOPNOTSUPP;
48	__u32 *pattrib = (__u32 *)value;
49	__u32 attrib;
50	FILE_BASIC_INFO info_buf;
51
52	if ((value == NULL) || (size != sizeof(__u32)))
53		return -ERANGE;
54
55	memset(&info_buf, 0, sizeof(info_buf));
56	attrib = *pattrib;
57	info_buf.Attributes = cpu_to_le32(attrib);
58	if (pTcon->ses->server->ops->set_file_info)
59		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
60				&info_buf, xid);
61	if (rc == 0)
62		CIFS_I(inode)->cifsAttrs = attrib;
63
64	return rc;
65}
66
67static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
68				  struct inode *inode, const char *full_path,
69				  const void *value, size_t size)
70{
71	ssize_t rc = -EOPNOTSUPP;
72	__u64 *pcreation_time = (__u64 *)value;
73	__u64 creation_time;
74	FILE_BASIC_INFO info_buf;
75
76	if ((value == NULL) || (size != sizeof(__u64)))
77		return -ERANGE;
78
79	memset(&info_buf, 0, sizeof(info_buf));
80	creation_time = *pcreation_time;
81	info_buf.CreationTime = cpu_to_le64(creation_time);
82	if (pTcon->ses->server->ops->set_file_info)
83		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
84				&info_buf, xid);
85	if (rc == 0)
86		CIFS_I(inode)->createtime = creation_time;
87
88	return rc;
89}
90
91static int cifs_xattr_set(const struct xattr_handler *handler,
92			  struct mnt_idmap *idmap,
93			  struct dentry *dentry, struct inode *inode,
94			  const char *name, const void *value,
95			  size_t size, int flags)
96{
97	int rc = -EOPNOTSUPP;
98	unsigned int xid;
99	struct super_block *sb = dentry->d_sb;
100	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
101	struct tcon_link *tlink;
102	struct cifs_tcon *pTcon;
103	const char *full_path;
104	void *page;
105
106	tlink = cifs_sb_tlink(cifs_sb);
107	if (IS_ERR(tlink))
108		return PTR_ERR(tlink);
109	pTcon = tlink_tcon(tlink);
110
111	xid = get_xid();
112	page = alloc_dentry_path();
113
114	full_path = build_path_from_dentry(dentry, page);
115	if (IS_ERR(full_path)) {
116		rc = PTR_ERR(full_path);
117		goto out;
118	}
119	/* return dos attributes as pseudo xattr */
120	/* return alt name if available as pseudo attr */
121
122	/* if proc/fs/cifs/streamstoxattr is set then
123		search server for EAs or streams to
124		returns as xattrs */
125	if (size > MAX_EA_VALUE_SIZE) {
126		cifs_dbg(FYI, "size of EA value too large\n");
127		rc = -EOPNOTSUPP;
128		goto out;
129	}
130
131	switch (handler->flags) {
132	case XATTR_USER:
133		cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
134		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
135		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
136			rc = cifs_attrib_set(xid, pTcon, inode, full_path,
137					value, size);
138			if (rc == 0) /* force revalidate of the inode */
139				CIFS_I(inode)->time = 0;
140			break;
141		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
142			   (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
143			rc = cifs_creation_time_set(xid, pTcon, inode,
144					full_path, value, size);
145			if (rc == 0) /* force revalidate of the inode */
146				CIFS_I(inode)->time = 0;
147			break;
148		}
149
150		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
151			goto out;
152
153		if (pTcon->ses->server->ops->set_EA) {
154			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
155				full_path, name, value, (__u16)size,
156				cifs_sb->local_nls, cifs_sb);
157			if (rc == 0)
158				inode_set_ctime_current(inode);
159		}
160		break;
161
162	case XATTR_CIFS_ACL:
163	case XATTR_CIFS_NTSD:
164	case XATTR_CIFS_NTSD_FULL: {
165		struct cifs_ntsd *pacl;
166
167		if (!value)
168			goto out;
169		pacl = kmalloc(size, GFP_KERNEL);
170		if (!pacl) {
171			rc = -ENOMEM;
172		} else {
173			memcpy(pacl, value, size);
174			if (pTcon->ses->server->ops->set_acl) {
175				int aclflags = 0;
176				rc = 0;
177
178				switch (handler->flags) {
179				case XATTR_CIFS_NTSD_FULL:
180					aclflags = (CIFS_ACL_OWNER |
181						    CIFS_ACL_GROUP |
182						    CIFS_ACL_DACL |
183						    CIFS_ACL_SACL);
184					break;
185				case XATTR_CIFS_NTSD:
186					aclflags = (CIFS_ACL_OWNER |
187						    CIFS_ACL_GROUP |
188						    CIFS_ACL_DACL);
189					break;
190				case XATTR_CIFS_ACL:
191				default:
192					aclflags = CIFS_ACL_DACL;
193				}
194
195				rc = pTcon->ses->server->ops->set_acl(pacl,
196					size, inode, full_path, aclflags);
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
208out:
209	free_dentry_path(page);
210	free_xid(xid);
211	cifs_put_tlink(tlink);
212	return rc;
213}
214
215static int cifs_attrib_get(struct dentry *dentry,
216			   struct inode *inode, void *value,
217			   size_t size)
218{
219	ssize_t rc;
220	__u32 *pattribute;
221
222	rc = cifs_revalidate_dentry_attr(dentry);
223
224	if (rc)
225		return rc;
226
227	if ((value == NULL) || (size == 0))
228		return sizeof(__u32);
229	else if (size < sizeof(__u32))
230		return -ERANGE;
231
232	/* return dos attributes as pseudo xattr */
233	pattribute = (__u32 *)value;
234	*pattribute = CIFS_I(inode)->cifsAttrs;
235
236	return sizeof(__u32);
237}
238
239static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
240				  void *value, size_t size)
241{
242	ssize_t rc;
243	__u64 *pcreatetime;
244
245	rc = cifs_revalidate_dentry_attr(dentry);
246	if (rc)
247		return rc;
248
249	if ((value == NULL) || (size == 0))
250		return sizeof(__u64);
251	else if (size < sizeof(__u64))
252		return -ERANGE;
253
254	/* return dos attributes as pseudo xattr */
255	pcreatetime = (__u64 *)value;
256	*pcreatetime = CIFS_I(inode)->createtime;
257	return sizeof(__u64);
258}
259
260
261static int cifs_xattr_get(const struct xattr_handler *handler,
262			  struct dentry *dentry, struct inode *inode,
263			  const char *name, void *value, size_t size)
264{
265	ssize_t rc = -EOPNOTSUPP;
266	unsigned int xid;
267	struct super_block *sb = dentry->d_sb;
268	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
269	struct tcon_link *tlink;
270	struct cifs_tcon *pTcon;
271	const char *full_path;
272	void *page;
273
274	tlink = cifs_sb_tlink(cifs_sb);
275	if (IS_ERR(tlink))
276		return PTR_ERR(tlink);
277	pTcon = tlink_tcon(tlink);
278
279	xid = get_xid();
280	page = alloc_dentry_path();
281
282	full_path = build_path_from_dentry(dentry, page);
283	if (IS_ERR(full_path)) {
284		rc = PTR_ERR(full_path);
285		goto out;
286	}
287
288	/* return alt name if available as pseudo attr */
289	switch (handler->flags) {
290	case XATTR_USER:
291		cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
292		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
293		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
294			rc = cifs_attrib_get(dentry, inode, value, size);
295			break;
296		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
297		    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
298			rc = cifs_creation_time_get(dentry, inode, value, size);
299			break;
300		}
301
302		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
303			goto out;
304
305		if (pTcon->ses->server->ops->query_all_EAs)
306			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
307				full_path, name, value, size, cifs_sb);
308		break;
309
310	case XATTR_CIFS_ACL:
311	case XATTR_CIFS_NTSD:
312	case XATTR_CIFS_NTSD_FULL: {
313		/*
314		 * fetch owner, DACL, and SACL if asked for full descriptor,
315		 * fetch owner and DACL otherwise
316		 */
317		u32 acllen, extra_info;
318		struct cifs_ntsd *pacl;
319
320		if (pTcon->ses->server->ops->get_acl == NULL)
321			goto out; /* rc already EOPNOTSUPP */
322
323		if (handler->flags == XATTR_CIFS_NTSD_FULL) {
324			extra_info = SACL_SECINFO;
325		} else {
326			extra_info = 0;
327		}
328		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
329				inode, full_path, &acllen, extra_info);
330		if (IS_ERR(pacl)) {
331			rc = PTR_ERR(pacl);
332			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
333				 __func__, rc);
334		} else {
335			if (value) {
336				if (acllen > size)
337					acllen = -ERANGE;
338				else
339					memcpy(value, pacl, acllen);
340			}
341			rc = acllen;
342			kfree(pacl);
343		}
344		break;
345	}
346	}
347
348	/* We could add an additional check for streams ie
349	    if proc/fs/cifs/streamstoxattr is set then
350		search server for EAs or streams to
351		returns as xattrs */
352
353	if (rc == -EINVAL)
354		rc = -EOPNOTSUPP;
355
356out:
357	free_dentry_path(page);
358	free_xid(xid);
359	cifs_put_tlink(tlink);
360	return rc;
361}
362
363ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
364{
365	ssize_t rc = -EOPNOTSUPP;
366	unsigned int xid;
367	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
368	struct tcon_link *tlink;
369	struct cifs_tcon *pTcon;
370	const char *full_path;
371	void *page;
372
373	if (unlikely(cifs_forced_shutdown(cifs_sb)))
374		return -EIO;
375
376	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
377		return -EOPNOTSUPP;
378
379	tlink = cifs_sb_tlink(cifs_sb);
380	if (IS_ERR(tlink))
381		return PTR_ERR(tlink);
382	pTcon = tlink_tcon(tlink);
383
384	xid = get_xid();
385	page = alloc_dentry_path();
386
387	full_path = build_path_from_dentry(direntry, page);
388	if (IS_ERR(full_path)) {
389		rc = PTR_ERR(full_path);
390		goto list_ea_exit;
391	}
392	/* return dos attributes as pseudo xattr */
393	/* return alt name if available as pseudo attr */
394
395	/* if proc/fs/cifs/streamstoxattr is set then
396		search server for EAs or streams to
397		returns as xattrs */
398
399	if (pTcon->ses->server->ops->query_all_EAs)
400		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
401				full_path, NULL, data, buf_size, cifs_sb);
402list_ea_exit:
403	free_dentry_path(page);
404	free_xid(xid);
405	cifs_put_tlink(tlink);
406	return rc;
407}
408
409static const struct xattr_handler cifs_user_xattr_handler = {
410	.prefix = XATTR_USER_PREFIX,
411	.flags = XATTR_USER,
412	.get = cifs_xattr_get,
413	.set = cifs_xattr_set,
414};
415
416/* os2.* attributes are treated like user.* attributes */
417static const struct xattr_handler cifs_os2_xattr_handler = {
418	.prefix = XATTR_OS2_PREFIX,
419	.flags = XATTR_USER,
420	.get = cifs_xattr_get,
421	.set = cifs_xattr_set,
422};
423
424static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
425	.name = CIFS_XATTR_CIFS_ACL,
426	.flags = XATTR_CIFS_ACL,
427	.get = cifs_xattr_get,
428	.set = cifs_xattr_set,
429};
430
431/*
432 * Although this is just an alias for the above, need to move away from
433 * confusing users and using the 20 year old term 'cifs' when it is no
434 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
435 * SMB3 and later are highly secure.
436 */
437static const struct xattr_handler smb3_acl_xattr_handler = {
438	.name = SMB3_XATTR_CIFS_ACL,
439	.flags = XATTR_CIFS_ACL,
440	.get = cifs_xattr_get,
441	.set = cifs_xattr_set,
442};
443
444static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
445	.name = CIFS_XATTR_CIFS_NTSD,
446	.flags = XATTR_CIFS_NTSD,
447	.get = cifs_xattr_get,
448	.set = cifs_xattr_set,
449};
450
451/*
452 * Although this is just an alias for the above, need to move away from
453 * confusing users and using the 20 year old term 'cifs' when it is no
454 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
455 * SMB3 and later are highly secure.
456 */
457static const struct xattr_handler smb3_ntsd_xattr_handler = {
458	.name = SMB3_XATTR_CIFS_NTSD,
459	.flags = XATTR_CIFS_NTSD,
460	.get = cifs_xattr_get,
461	.set = cifs_xattr_set,
462};
463
464static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
465	.name = CIFS_XATTR_CIFS_NTSD_FULL,
466	.flags = XATTR_CIFS_NTSD_FULL,
467	.get = cifs_xattr_get,
468	.set = cifs_xattr_set,
469};
470
471/*
472 * Although this is just an alias for the above, need to move away from
473 * confusing users and using the 20 year old term 'cifs' when it is no
474 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
475 * SMB3 and later are highly secure.
476 */
477static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
478	.name = SMB3_XATTR_CIFS_NTSD_FULL,
479	.flags = XATTR_CIFS_NTSD_FULL,
480	.get = cifs_xattr_get,
481	.set = cifs_xattr_set,
482};
483
484const struct xattr_handler * const cifs_xattr_handlers[] = {
485	&cifs_user_xattr_handler,
486	&cifs_os2_xattr_handler,
487	&cifs_cifs_acl_xattr_handler,
488	&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
489	&cifs_cifs_ntsd_xattr_handler,
490	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
491	&cifs_cifs_ntsd_full_xattr_handler,
492	&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
493	NULL
494};
495