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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 
40 enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
41 	XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };
42 
cifs_attrib_set(unsigned int xid,struct cifs_tcon * pTcon,struct inode * inode,const char * full_path,const void * value,size_t size)43 static 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 
cifs_creation_time_set(unsigned int xid,struct cifs_tcon * pTcon,struct inode * inode,const char * full_path,const void * value,size_t size)67 static 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 
cifs_xattr_set(const struct xattr_handler * handler,struct user_namespace * mnt_userns,struct dentry * dentry,struct inode * inode,const char * name,const void * value,size_t size,int flags)91 static int cifs_xattr_set(const struct xattr_handler *handler,
92 			  struct user_namespace *mnt_userns,
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 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
208 	case XATTR_ACL_ACCESS:
209 #ifdef CONFIG_CIFS_POSIX
210 		if (!value)
211 			goto out;
212 		if (sb->s_flags & SB_POSIXACL)
213 			rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
214 				value, (const int)size,
215 				ACL_TYPE_ACCESS, cifs_sb->local_nls,
216 				cifs_remap(cifs_sb));
217 #endif  /* CONFIG_CIFS_POSIX */
218 		break;
219 
220 	case XATTR_ACL_DEFAULT:
221 #ifdef CONFIG_CIFS_POSIX
222 		if (!value)
223 			goto out;
224 		if (sb->s_flags & SB_POSIXACL)
225 			rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
226 				value, (const int)size,
227 				ACL_TYPE_DEFAULT, cifs_sb->local_nls,
228 				cifs_remap(cifs_sb));
229 #endif  /* CONFIG_CIFS_POSIX */
230 		break;
231 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
232 	}
233 
234 out:
235 	free_dentry_path(page);
236 	free_xid(xid);
237 	cifs_put_tlink(tlink);
238 	return rc;
239 }
240 
cifs_attrib_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)241 static int cifs_attrib_get(struct dentry *dentry,
242 			   struct inode *inode, void *value,
243 			   size_t size)
244 {
245 	ssize_t rc;
246 	__u32 *pattribute;
247 
248 	rc = cifs_revalidate_dentry_attr(dentry);
249 
250 	if (rc)
251 		return rc;
252 
253 	if ((value == NULL) || (size == 0))
254 		return sizeof(__u32);
255 	else if (size < sizeof(__u32))
256 		return -ERANGE;
257 
258 	/* return dos attributes as pseudo xattr */
259 	pattribute = (__u32 *)value;
260 	*pattribute = CIFS_I(inode)->cifsAttrs;
261 
262 	return sizeof(__u32);
263 }
264 
cifs_creation_time_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)265 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
266 				  void *value, size_t size)
267 {
268 	ssize_t rc;
269 	__u64 *pcreatetime;
270 
271 	rc = cifs_revalidate_dentry_attr(dentry);
272 	if (rc)
273 		return rc;
274 
275 	if ((value == NULL) || (size == 0))
276 		return sizeof(__u64);
277 	else if (size < sizeof(__u64))
278 		return -ERANGE;
279 
280 	/* return dos attributes as pseudo xattr */
281 	pcreatetime = (__u64 *)value;
282 	*pcreatetime = CIFS_I(inode)->createtime;
283 	return sizeof(__u64);
284 }
285 
286 
cifs_xattr_get(const struct xattr_handler * handler,struct dentry * dentry,struct inode * inode,const char * name,void * value,size_t size)287 static int cifs_xattr_get(const struct xattr_handler *handler,
288 			  struct dentry *dentry, struct inode *inode,
289 			  const char *name, void *value, size_t size)
290 {
291 	ssize_t rc = -EOPNOTSUPP;
292 	unsigned int xid;
293 	struct super_block *sb = dentry->d_sb;
294 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
295 	struct tcon_link *tlink;
296 	struct cifs_tcon *pTcon;
297 	const char *full_path;
298 	void *page;
299 
300 	tlink = cifs_sb_tlink(cifs_sb);
301 	if (IS_ERR(tlink))
302 		return PTR_ERR(tlink);
303 	pTcon = tlink_tcon(tlink);
304 
305 	xid = get_xid();
306 	page = alloc_dentry_path();
307 
308 	full_path = build_path_from_dentry(dentry, page);
309 	if (IS_ERR(full_path)) {
310 		rc = PTR_ERR(full_path);
311 		goto out;
312 	}
313 
314 	/* return alt name if available as pseudo attr */
315 	switch (handler->flags) {
316 	case XATTR_USER:
317 		cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
318 		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
319 		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
320 			rc = cifs_attrib_get(dentry, inode, value, size);
321 			break;
322 		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
323 		    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
324 			rc = cifs_creation_time_get(dentry, inode, value, size);
325 			break;
326 		}
327 
328 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
329 			goto out;
330 
331 		if (pTcon->ses->server->ops->query_all_EAs)
332 			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
333 				full_path, name, value, size, cifs_sb);
334 		break;
335 
336 	case XATTR_CIFS_ACL:
337 	case XATTR_CIFS_NTSD:
338 	case XATTR_CIFS_NTSD_FULL: {
339 		/*
340 		 * fetch owner, DACL, and SACL if asked for full descriptor,
341 		 * fetch owner and DACL otherwise
342 		 */
343 		u32 acllen, extra_info;
344 		struct cifs_ntsd *pacl;
345 
346 		if (pTcon->ses->server->ops->get_acl == NULL)
347 			goto out; /* rc already EOPNOTSUPP */
348 
349 		if (handler->flags == XATTR_CIFS_NTSD_FULL) {
350 			extra_info = SACL_SECINFO;
351 		} else {
352 			extra_info = 0;
353 		}
354 		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
355 				inode, full_path, &acllen, extra_info);
356 		if (IS_ERR(pacl)) {
357 			rc = PTR_ERR(pacl);
358 			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
359 				 __func__, rc);
360 		} else {
361 			if (value) {
362 				if (acllen > size)
363 					acllen = -ERANGE;
364 				else
365 					memcpy(value, pacl, acllen);
366 			}
367 			rc = acllen;
368 			kfree(pacl);
369 		}
370 		break;
371 	}
372 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
373 	case XATTR_ACL_ACCESS:
374 #ifdef CONFIG_CIFS_POSIX
375 		if (sb->s_flags & SB_POSIXACL)
376 			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
377 				value, size, ACL_TYPE_ACCESS,
378 				cifs_sb->local_nls,
379 				cifs_remap(cifs_sb));
380 #endif  /* CONFIG_CIFS_POSIX */
381 		break;
382 
383 	case XATTR_ACL_DEFAULT:
384 #ifdef CONFIG_CIFS_POSIX
385 		if (sb->s_flags & SB_POSIXACL)
386 			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
387 				value, size, ACL_TYPE_DEFAULT,
388 				cifs_sb->local_nls,
389 				cifs_remap(cifs_sb));
390 #endif  /* CONFIG_CIFS_POSIX */
391 		break;
392 #endif /* ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
393 	}
394 
395 	/* We could add an additional check for streams ie
396 	    if proc/fs/cifs/streamstoxattr is set then
397 		search server for EAs or streams to
398 		returns as xattrs */
399 
400 	if (rc == -EINVAL)
401 		rc = -EOPNOTSUPP;
402 
403 out:
404 	free_dentry_path(page);
405 	free_xid(xid);
406 	cifs_put_tlink(tlink);
407 	return rc;
408 }
409 
cifs_listxattr(struct dentry * direntry,char * data,size_t buf_size)410 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
411 {
412 	ssize_t rc = -EOPNOTSUPP;
413 	unsigned int xid;
414 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
415 	struct tcon_link *tlink;
416 	struct cifs_tcon *pTcon;
417 	const char *full_path;
418 	void *page;
419 
420 	if (unlikely(cifs_forced_shutdown(cifs_sb)))
421 		return -EIO;
422 
423 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
424 		return -EOPNOTSUPP;
425 
426 	tlink = cifs_sb_tlink(cifs_sb);
427 	if (IS_ERR(tlink))
428 		return PTR_ERR(tlink);
429 	pTcon = tlink_tcon(tlink);
430 
431 	xid = get_xid();
432 	page = alloc_dentry_path();
433 
434 	full_path = build_path_from_dentry(direntry, page);
435 	if (IS_ERR(full_path)) {
436 		rc = PTR_ERR(full_path);
437 		goto list_ea_exit;
438 	}
439 	/* return dos attributes as pseudo xattr */
440 	/* return alt name if available as pseudo attr */
441 
442 	/* if proc/fs/cifs/streamstoxattr is set then
443 		search server for EAs or streams to
444 		returns as xattrs */
445 
446 	if (pTcon->ses->server->ops->query_all_EAs)
447 		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
448 				full_path, NULL, data, buf_size, cifs_sb);
449 list_ea_exit:
450 	free_dentry_path(page);
451 	free_xid(xid);
452 	cifs_put_tlink(tlink);
453 	return rc;
454 }
455 
456 static const struct xattr_handler cifs_user_xattr_handler = {
457 	.prefix = XATTR_USER_PREFIX,
458 	.flags = XATTR_USER,
459 	.get = cifs_xattr_get,
460 	.set = cifs_xattr_set,
461 };
462 
463 /* os2.* attributes are treated like user.* attributes */
464 static const struct xattr_handler cifs_os2_xattr_handler = {
465 	.prefix = XATTR_OS2_PREFIX,
466 	.flags = XATTR_USER,
467 	.get = cifs_xattr_get,
468 	.set = cifs_xattr_set,
469 };
470 
471 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
472 	.name = CIFS_XATTR_CIFS_ACL,
473 	.flags = XATTR_CIFS_ACL,
474 	.get = cifs_xattr_get,
475 	.set = cifs_xattr_set,
476 };
477 
478 /*
479  * Although this is just an alias for the above, need to move away from
480  * confusing users and using the 20 year old term 'cifs' when it is no
481  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
482  * SMB3 and later are highly secure.
483  */
484 static const struct xattr_handler smb3_acl_xattr_handler = {
485 	.name = SMB3_XATTR_CIFS_ACL,
486 	.flags = XATTR_CIFS_ACL,
487 	.get = cifs_xattr_get,
488 	.set = cifs_xattr_set,
489 };
490 
491 static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
492 	.name = CIFS_XATTR_CIFS_NTSD,
493 	.flags = XATTR_CIFS_NTSD,
494 	.get = cifs_xattr_get,
495 	.set = cifs_xattr_set,
496 };
497 
498 /*
499  * Although this is just an alias for the above, need to move away from
500  * confusing users and using the 20 year old term 'cifs' when it is no
501  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
502  * SMB3 and later are highly secure.
503  */
504 static const struct xattr_handler smb3_ntsd_xattr_handler = {
505 	.name = SMB3_XATTR_CIFS_NTSD,
506 	.flags = XATTR_CIFS_NTSD,
507 	.get = cifs_xattr_get,
508 	.set = cifs_xattr_set,
509 };
510 
511 static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
512 	.name = CIFS_XATTR_CIFS_NTSD_FULL,
513 	.flags = XATTR_CIFS_NTSD_FULL,
514 	.get = cifs_xattr_get,
515 	.set = cifs_xattr_set,
516 };
517 
518 /*
519  * Although this is just an alias for the above, need to move away from
520  * confusing users and using the 20 year old term 'cifs' when it is no
521  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
522  * SMB3 and later are highly secure.
523  */
524 static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
525 	.name = SMB3_XATTR_CIFS_NTSD_FULL,
526 	.flags = XATTR_CIFS_NTSD_FULL,
527 	.get = cifs_xattr_get,
528 	.set = cifs_xattr_set,
529 };
530 
531 
532 static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
533 	.name = XATTR_NAME_POSIX_ACL_ACCESS,
534 	.flags = XATTR_ACL_ACCESS,
535 	.get = cifs_xattr_get,
536 	.set = cifs_xattr_set,
537 };
538 
539 static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
540 	.name = XATTR_NAME_POSIX_ACL_DEFAULT,
541 	.flags = XATTR_ACL_DEFAULT,
542 	.get = cifs_xattr_get,
543 	.set = cifs_xattr_set,
544 };
545 
546 const struct xattr_handler *cifs_xattr_handlers[] = {
547 	&cifs_user_xattr_handler,
548 	&cifs_os2_xattr_handler,
549 	&cifs_cifs_acl_xattr_handler,
550 	&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
551 	&cifs_cifs_ntsd_xattr_handler,
552 	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
553 	&cifs_cifs_ntsd_full_xattr_handler,
554 	&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
555 	&cifs_posix_acl_access_xattr_handler,
556 	&cifs_posix_acl_default_xattr_handler,
557 	NULL
558 };
559