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 65535
 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/* 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
 42static int cifs_xattr_set(const struct xattr_handler *handler,
 43			  struct dentry *dentry, struct inode *inode,
 44			  const char *name, const void *value,
 45			  size_t size, int flags)
 46{
 47	int rc = -EOPNOTSUPP;
 48	unsigned int xid;
 49	struct super_block *sb = dentry->d_sb;
 50	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 51	struct tcon_link *tlink;
 52	struct cifs_tcon *pTcon;
 53	char *full_path;
 54
 55	tlink = cifs_sb_tlink(cifs_sb);
 56	if (IS_ERR(tlink))
 57		return PTR_ERR(tlink);
 58	pTcon = tlink_tcon(tlink);
 59
 60	xid = get_xid();
 61
 62	full_path = build_path_from_dentry(dentry);
 63	if (full_path == NULL) {
 64		rc = -ENOMEM;
 65		goto out;
 66	}
 67	/* return dos attributes as pseudo xattr */
 68	/* return alt name if available as pseudo attr */
 69
 70	/* if proc/fs/cifs/streamstoxattr is set then
 71		search server for EAs or streams to
 72		returns as xattrs */
 73	if (size > MAX_EA_VALUE_SIZE) {
 74		cifs_dbg(FYI, "size of EA value too large\n");
 75		rc = -EOPNOTSUPP;
 76		goto out;
 77	}
 78
 79	switch (handler->flags) {
 80	case XATTR_USER:
 81		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 82			goto out;
 83
 84		if (pTcon->ses->server->ops->set_EA)
 85			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
 86				full_path, name, value, (__u16)size,
 87				cifs_sb->local_nls, cifs_remap(cifs_sb));
 88		break;
 89
 90	case XATTR_CIFS_ACL: {
 91#ifdef CONFIG_CIFS_ACL
 92		struct cifs_ntsd *pacl;
 93
 94		if (!value)
 95			goto out;
 96		pacl = kmalloc(size, GFP_KERNEL);
 97		if (!pacl) {
 98			rc = -ENOMEM;
 99		} else {
100			memcpy(pacl, value, size);
101			if (value &&
102			    pTcon->ses->server->ops->set_acl)
103				rc = pTcon->ses->server->ops->set_acl(pacl,
104						size, inode,
105						full_path, CIFS_ACL_DACL);
106			else
107				rc = -EOPNOTSUPP;
108			if (rc == 0) /* force revalidate of the inode */
109				CIFS_I(inode)->time = 0;
110			kfree(pacl);
111		}
112#endif /* CONFIG_CIFS_ACL */
113		break;
114	}
115
116	case XATTR_ACL_ACCESS:
117#ifdef CONFIG_CIFS_POSIX
118		if (!value)
119			goto out;
120		if (sb->s_flags & MS_POSIXACL)
121			rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
122				value, (const int)size,
123				ACL_TYPE_ACCESS, cifs_sb->local_nls,
124				cifs_remap(cifs_sb));
125#endif  /* CONFIG_CIFS_POSIX */
126		break;
127
128	case XATTR_ACL_DEFAULT:
129#ifdef CONFIG_CIFS_POSIX
130		if (!value)
131			goto out;
132		if (sb->s_flags & MS_POSIXACL)
133			rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
134				value, (const int)size,
135				ACL_TYPE_DEFAULT, cifs_sb->local_nls,
136				cifs_remap(cifs_sb));
137#endif  /* CONFIG_CIFS_POSIX */
138		break;
139	}
140
141out:
142	kfree(full_path);
143	free_xid(xid);
144	cifs_put_tlink(tlink);
145	return rc;
146}
147
148static int cifs_attrib_get(struct dentry *dentry,
149			   struct inode *inode, void *value,
150			   size_t size)
151{
152	ssize_t rc;
153	__u32 *pattribute;
154
155	rc = cifs_revalidate_dentry_attr(dentry);
156
157	if (rc)
158		return rc;
159
160	if ((value == NULL) || (size == 0))
161		return sizeof(__u32);
162	else if (size < sizeof(__u32))
163		return -ERANGE;
164
165	/* return dos attributes as pseudo xattr */
166	pattribute = (__u32 *)value;
167	*pattribute = CIFS_I(inode)->cifsAttrs;
168
169	return sizeof(__u32);
170}
171
172static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
173				  void *value, size_t size)
174{
175	ssize_t rc;
176	__u64 * pcreatetime;
177
178	rc = cifs_revalidate_dentry_attr(dentry);
179	if (rc)
180		return rc;
181
182	if ((value == NULL) || (size == 0))
183		return sizeof(__u64);
184	else if (size < sizeof(__u64))
185		return -ERANGE;
186
187	/* return dos attributes as pseudo xattr */
188	pcreatetime = (__u64 *)value;
189	*pcreatetime = CIFS_I(inode)->createtime;
190	return sizeof(__u64);
191
192	return rc;
193}
194
195
196static int cifs_xattr_get(const struct xattr_handler *handler,
197			  struct dentry *dentry, struct inode *inode,
198			  const char *name, void *value, size_t size)
199{
200	ssize_t rc = -EOPNOTSUPP;
201	unsigned int xid;
202	struct super_block *sb = dentry->d_sb;
203	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
204	struct tcon_link *tlink;
205	struct cifs_tcon *pTcon;
206	char *full_path;
207
208	tlink = cifs_sb_tlink(cifs_sb);
209	if (IS_ERR(tlink))
210		return PTR_ERR(tlink);
211	pTcon = tlink_tcon(tlink);
212
213	xid = get_xid();
214
215	full_path = build_path_from_dentry(dentry);
216	if (full_path == NULL) {
217		rc = -ENOMEM;
218		goto out;
219	}
220
221	/* return alt name if available as pseudo attr */
222	switch (handler->flags) {
223	case XATTR_USER:
224		cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
225		if (strcmp(name, CIFS_XATTR_ATTRIB) == 0) {
226			rc = cifs_attrib_get(dentry, inode, value, size);
227			break;
228		} else if (strcmp(name, CIFS_XATTR_CREATETIME) == 0) {
229			rc = cifs_creation_time_get(dentry, inode, value, size);
230			break;
231		}
232
233		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
234			goto out;
235
236		if (pTcon->ses->server->ops->query_all_EAs)
237			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
238				full_path, name, value, size,
239				cifs_sb->local_nls, cifs_remap(cifs_sb));
240		break;
241
242	case XATTR_CIFS_ACL: {
243#ifdef CONFIG_CIFS_ACL
244		u32 acllen;
245		struct cifs_ntsd *pacl;
246
247		if (pTcon->ses->server->ops->get_acl == NULL)
248			goto out; /* rc already EOPNOTSUPP */
249
250		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
251				inode, full_path, &acllen);
252		if (IS_ERR(pacl)) {
253			rc = PTR_ERR(pacl);
254			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
255				 __func__, rc);
256		} else {
257			if (value) {
258				if (acllen > size)
259					acllen = -ERANGE;
260				else
261					memcpy(value, pacl, acllen);
262			}
263			rc = acllen;
264			kfree(pacl);
265		}
266#endif  /* CONFIG_CIFS_ACL */
267		break;
268	}
269
270	case XATTR_ACL_ACCESS:
271#ifdef CONFIG_CIFS_POSIX
272		if (sb->s_flags & MS_POSIXACL)
273			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
274				value, size, ACL_TYPE_ACCESS,
275				cifs_sb->local_nls,
276				cifs_remap(cifs_sb));
277#endif  /* CONFIG_CIFS_POSIX */
278		break;
279
280	case XATTR_ACL_DEFAULT:
281#ifdef CONFIG_CIFS_POSIX
282		if (sb->s_flags & MS_POSIXACL)
283			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
284				value, size, ACL_TYPE_DEFAULT,
285				cifs_sb->local_nls,
286				cifs_remap(cifs_sb));
287#endif  /* CONFIG_CIFS_POSIX */
288		break;
289	}
290
291	/* We could add an additional check for streams ie
292	    if proc/fs/cifs/streamstoxattr is set then
293		search server for EAs or streams to
294		returns as xattrs */
295
296	if (rc == -EINVAL)
297		rc = -EOPNOTSUPP;
298
299out:
300	kfree(full_path);
301	free_xid(xid);
302	cifs_put_tlink(tlink);
303	return rc;
304}
305
306ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
307{
308	ssize_t rc = -EOPNOTSUPP;
309	unsigned int xid;
310	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
311	struct tcon_link *tlink;
312	struct cifs_tcon *pTcon;
313	char *full_path;
314
315	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
316		return -EOPNOTSUPP;
317
318	tlink = cifs_sb_tlink(cifs_sb);
319	if (IS_ERR(tlink))
320		return PTR_ERR(tlink);
321	pTcon = tlink_tcon(tlink);
322
323	xid = get_xid();
324
325	full_path = build_path_from_dentry(direntry);
326	if (full_path == NULL) {
327		rc = -ENOMEM;
328		goto list_ea_exit;
329	}
330	/* return dos attributes as pseudo xattr */
331	/* return alt name if available as pseudo attr */
332
333	/* if proc/fs/cifs/streamstoxattr is set then
334		search server for EAs or streams to
335		returns as xattrs */
336
337	if (pTcon->ses->server->ops->query_all_EAs)
338		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
339				full_path, NULL, data, buf_size,
340				cifs_sb->local_nls, cifs_remap(cifs_sb));
341list_ea_exit:
342	kfree(full_path);
343	free_xid(xid);
344	cifs_put_tlink(tlink);
345	return rc;
346}
347
348static const struct xattr_handler cifs_user_xattr_handler = {
349	.prefix = XATTR_USER_PREFIX,
350	.flags = XATTR_USER,
351	.get = cifs_xattr_get,
352	.set = cifs_xattr_set,
353};
354
355/* os2.* attributes are treated like user.* attributes */
356static const struct xattr_handler cifs_os2_xattr_handler = {
357	.prefix = XATTR_OS2_PREFIX,
358	.flags = XATTR_USER,
359	.get = cifs_xattr_get,
360	.set = cifs_xattr_set,
361};
362
363static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
364	.name = CIFS_XATTR_CIFS_ACL,
365	.flags = XATTR_CIFS_ACL,
366	.get = cifs_xattr_get,
367	.set = cifs_xattr_set,
368};
369
370static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
371	.name = XATTR_NAME_POSIX_ACL_ACCESS,
372	.flags = XATTR_ACL_ACCESS,
373	.get = cifs_xattr_get,
374	.set = cifs_xattr_set,
375};
376
377static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
378	.name = XATTR_NAME_POSIX_ACL_DEFAULT,
379	.flags = XATTR_ACL_DEFAULT,
380	.get = cifs_xattr_get,
381	.set = cifs_xattr_set,
382};
383
384const struct xattr_handler *cifs_xattr_handlers[] = {
385	&cifs_user_xattr_handler,
386	&cifs_os2_xattr_handler,
387	&cifs_cifs_acl_xattr_handler,
388	&cifs_posix_acl_access_xattr_handler,
389	&cifs_posix_acl_default_xattr_handler,
390	NULL
391};