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_DOS_ATTRIB "user.DosAttrib"
36#define CIFS_XATTR_CIFS_ACL "system.cifs_acl"
37
38/* BB need to add server (Samba e.g) support for security and trusted prefix */
39
40int cifs_removexattr(struct dentry *direntry, const char *ea_name)
41{
42	int rc = -EOPNOTSUPP;
43#ifdef CONFIG_CIFS_XATTR
44	unsigned int xid;
45	struct cifs_sb_info *cifs_sb;
46	struct tcon_link *tlink;
47	struct cifs_tcon *pTcon;
48	struct super_block *sb;
49	char *full_path = NULL;
50
51	if (direntry == NULL)
52		return -EIO;
53	if (d_really_is_negative(direntry))
54		return -EIO;
55	sb = d_inode(direntry)->i_sb;
56	if (sb == NULL)
57		return -EIO;
58
59	cifs_sb = CIFS_SB(sb);
60	tlink = cifs_sb_tlink(cifs_sb);
61	if (IS_ERR(tlink))
62		return PTR_ERR(tlink);
63	pTcon = tlink_tcon(tlink);
64
65	xid = get_xid();
66
67	full_path = build_path_from_dentry(direntry);
68	if (full_path == NULL) {
69		rc = -ENOMEM;
70		goto remove_ea_exit;
71	}
72	if (ea_name == NULL) {
73		cifs_dbg(FYI, "Null xattr names not supported\n");
74	} else if (strncmp(ea_name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)
75		&& (strncmp(ea_name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN))) {
76		cifs_dbg(FYI,
77			 "illegal xattr request %s (only user namespace supported)\n",
78			 ea_name);
79		/* BB what if no namespace prefix? */
80		/* Should we just pass them to server, except for
81		system and perhaps security prefixes? */
82	} else {
83		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
84			goto remove_ea_exit;
85
86		ea_name += XATTR_USER_PREFIX_LEN; /* skip past user. prefix */
87		if (pTcon->ses->server->ops->set_EA)
88			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
89				full_path, ea_name, NULL, (__u16)0,
90				cifs_sb->local_nls, cifs_remap(cifs_sb));
91	}
92remove_ea_exit:
93	kfree(full_path);
94	free_xid(xid);
95	cifs_put_tlink(tlink);
96#endif
97	return rc;
98}
99
100int cifs_setxattr(struct dentry *direntry, const char *ea_name,
101		  const void *ea_value, size_t value_size, int flags)
102{
103	int rc = -EOPNOTSUPP;
104#ifdef CONFIG_CIFS_XATTR
105	unsigned int xid;
106	struct cifs_sb_info *cifs_sb;
107	struct tcon_link *tlink;
108	struct cifs_tcon *pTcon;
109	struct super_block *sb;
110	char *full_path;
111
112	if (direntry == NULL)
113		return -EIO;
114	if (d_really_is_negative(direntry))
115		return -EIO;
116	sb = d_inode(direntry)->i_sb;
117	if (sb == NULL)
118		return -EIO;
119
120	cifs_sb = CIFS_SB(sb);
121	tlink = cifs_sb_tlink(cifs_sb);
122	if (IS_ERR(tlink))
123		return PTR_ERR(tlink);
124	pTcon = tlink_tcon(tlink);
125
126	xid = get_xid();
127
128	full_path = build_path_from_dentry(direntry);
129	if (full_path == NULL) {
130		rc = -ENOMEM;
131		goto set_ea_exit;
132	}
133	/* return dos attributes as pseudo xattr */
134	/* return alt name if available as pseudo attr */
135
136	/* if proc/fs/cifs/streamstoxattr is set then
137		search server for EAs or streams to
138		returns as xattrs */
139	if (value_size > MAX_EA_VALUE_SIZE) {
140		cifs_dbg(FYI, "size of EA value too large\n");
141		rc = -EOPNOTSUPP;
142		goto set_ea_exit;
143	}
144
145	if (ea_name == NULL) {
146		cifs_dbg(FYI, "Null xattr names not supported\n");
147	} else if (strncmp(ea_name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)
148		   == 0) {
149		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
150			goto set_ea_exit;
151		if (strncmp(ea_name, CIFS_XATTR_DOS_ATTRIB, 14) == 0)
152			cifs_dbg(FYI, "attempt to set cifs inode metadata\n");
153
154		ea_name += XATTR_USER_PREFIX_LEN; /* skip past user. prefix */
155		if (pTcon->ses->server->ops->set_EA)
156			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
157				full_path, ea_name, ea_value, (__u16)value_size,
158				cifs_sb->local_nls, cifs_remap(cifs_sb));
159	} else if (strncmp(ea_name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)
160		   == 0) {
161		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
162			goto set_ea_exit;
163
164		ea_name += XATTR_OS2_PREFIX_LEN; /* skip past os2. prefix */
165		if (pTcon->ses->server->ops->set_EA)
166			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
167				full_path, ea_name, ea_value, (__u16)value_size,
168				cifs_sb->local_nls, cifs_remap(cifs_sb));
169	} else if (strncmp(ea_name, CIFS_XATTR_CIFS_ACL,
170			strlen(CIFS_XATTR_CIFS_ACL)) == 0) {
171#ifdef CONFIG_CIFS_ACL
172		struct cifs_ntsd *pacl;
173		pacl = kmalloc(value_size, GFP_KERNEL);
174		if (!pacl) {
175			rc = -ENOMEM;
176		} else {
177			memcpy(pacl, ea_value, value_size);
178			if (pTcon->ses->server->ops->set_acl)
179				rc = pTcon->ses->server->ops->set_acl(pacl,
180						value_size, d_inode(direntry),
181						full_path, CIFS_ACL_DACL);
182			else
183				rc = -EOPNOTSUPP;
184			if (rc == 0) /* force revalidate of the inode */
185				CIFS_I(d_inode(direntry))->time = 0;
186			kfree(pacl);
187		}
188#else
189		cifs_dbg(FYI, "Set CIFS ACL not supported yet\n");
190#endif /* CONFIG_CIFS_ACL */
191	} else {
192		int temp;
193		temp = strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,
194			strlen(POSIX_ACL_XATTR_ACCESS));
195		if (temp == 0) {
196#ifdef CONFIG_CIFS_POSIX
197			if (sb->s_flags & MS_POSIXACL)
198				rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
199					ea_value, (const int)value_size,
200					ACL_TYPE_ACCESS, cifs_sb->local_nls,
201					cifs_remap(cifs_sb));
202			cifs_dbg(FYI, "set POSIX ACL rc %d\n", rc);
203#else
204			cifs_dbg(FYI, "set POSIX ACL not supported\n");
205#endif
206		} else if (strncmp(ea_name, POSIX_ACL_XATTR_DEFAULT,
207				   strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {
208#ifdef CONFIG_CIFS_POSIX
209			if (sb->s_flags & MS_POSIXACL)
210				rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
211					ea_value, (const int)value_size,
212					ACL_TYPE_DEFAULT, cifs_sb->local_nls,
213					cifs_remap(cifs_sb));
214			cifs_dbg(FYI, "set POSIX default ACL rc %d\n", rc);
215#else
216			cifs_dbg(FYI, "set default POSIX ACL not supported\n");
217#endif
218		} else {
219			cifs_dbg(FYI, "illegal xattr request %s (only user namespace supported)\n",
220				 ea_name);
221		  /* BB what if no namespace prefix? */
222		  /* Should we just pass them to server, except for
223		  system and perhaps security prefixes? */
224		}
225	}
226
227set_ea_exit:
228	kfree(full_path);
229	free_xid(xid);
230	cifs_put_tlink(tlink);
231#endif
232	return rc;
233}
234
235ssize_t cifs_getxattr(struct dentry *direntry, const char *ea_name,
236	void *ea_value, size_t buf_size)
237{
238	ssize_t rc = -EOPNOTSUPP;
239#ifdef CONFIG_CIFS_XATTR
240	unsigned int xid;
241	struct cifs_sb_info *cifs_sb;
242	struct tcon_link *tlink;
243	struct cifs_tcon *pTcon;
244	struct super_block *sb;
245	char *full_path;
246
247	if (direntry == NULL)
248		return -EIO;
249	if (d_really_is_negative(direntry))
250		return -EIO;
251	sb = d_inode(direntry)->i_sb;
252	if (sb == NULL)
253		return -EIO;
254
255	cifs_sb = CIFS_SB(sb);
256	tlink = cifs_sb_tlink(cifs_sb);
257	if (IS_ERR(tlink))
258		return PTR_ERR(tlink);
259	pTcon = tlink_tcon(tlink);
260
261	xid = get_xid();
262
263	full_path = build_path_from_dentry(direntry);
264	if (full_path == NULL) {
265		rc = -ENOMEM;
266		goto get_ea_exit;
267	}
268	/* return dos attributes as pseudo xattr */
269	/* return alt name if available as pseudo attr */
270	if (ea_name == NULL) {
271		cifs_dbg(FYI, "Null xattr names not supported\n");
272	} else if (strncmp(ea_name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)
273		   == 0) {
274		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
275			goto get_ea_exit;
276
277		if (strncmp(ea_name, CIFS_XATTR_DOS_ATTRIB, 14) == 0) {
278			cifs_dbg(FYI, "attempt to query cifs inode metadata\n");
279			/* revalidate/getattr then populate from inode */
280		} /* BB add else when above is implemented */
281		ea_name += XATTR_USER_PREFIX_LEN; /* skip past user. prefix */
282		if (pTcon->ses->server->ops->query_all_EAs)
283			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
284				full_path, ea_name, ea_value, buf_size,
285				cifs_sb->local_nls, cifs_remap(cifs_sb));
286	} else if (strncmp(ea_name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
287		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
288			goto get_ea_exit;
289
290		ea_name += XATTR_OS2_PREFIX_LEN; /* skip past os2. prefix */
291		if (pTcon->ses->server->ops->query_all_EAs)
292			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
293				full_path, ea_name, ea_value, buf_size,
294				cifs_sb->local_nls, cifs_remap(cifs_sb));
295	} else if (strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,
296			  strlen(POSIX_ACL_XATTR_ACCESS)) == 0) {
297#ifdef CONFIG_CIFS_POSIX
298		if (sb->s_flags & MS_POSIXACL)
299			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
300				ea_value, buf_size, ACL_TYPE_ACCESS,
301				cifs_sb->local_nls,
302				cifs_remap(cifs_sb));
303#else
304		cifs_dbg(FYI, "Query POSIX ACL not supported yet\n");
305#endif /* CONFIG_CIFS_POSIX */
306	} else if (strncmp(ea_name, POSIX_ACL_XATTR_DEFAULT,
307			  strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {
308#ifdef CONFIG_CIFS_POSIX
309		if (sb->s_flags & MS_POSIXACL)
310			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
311				ea_value, buf_size, ACL_TYPE_DEFAULT,
312				cifs_sb->local_nls,
313				cifs_remap(cifs_sb));
314#else
315		cifs_dbg(FYI, "Query POSIX default ACL not supported yet\n");
316#endif /* CONFIG_CIFS_POSIX */
317	} else if (strncmp(ea_name, CIFS_XATTR_CIFS_ACL,
318				strlen(CIFS_XATTR_CIFS_ACL)) == 0) {
319#ifdef CONFIG_CIFS_ACL
320			u32 acllen;
321			struct cifs_ntsd *pacl;
322
323			if (pTcon->ses->server->ops->get_acl == NULL)
324				goto get_ea_exit; /* rc already EOPNOTSUPP */
325
326			pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
327					d_inode(direntry), full_path, &acllen);
328			if (IS_ERR(pacl)) {
329				rc = PTR_ERR(pacl);
330				cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
331					 __func__, rc);
332			} else {
333				if (ea_value) {
334					if (acllen > buf_size)
335						acllen = -ERANGE;
336					else
337						memcpy(ea_value, pacl, acllen);
338				}
339				rc = acllen;
340				kfree(pacl);
341			}
342#else
343			cifs_dbg(FYI, "Query CIFS ACL not supported yet\n");
344#endif /* CONFIG_CIFS_ACL */
345	} else if (strncmp(ea_name,
346		  XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) == 0) {
347		cifs_dbg(FYI, "Trusted xattr namespace not supported yet\n");
348	} else if (strncmp(ea_name,
349		  XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) == 0) {
350		cifs_dbg(FYI, "Security xattr namespace not supported yet\n");
351	} else
352		cifs_dbg(FYI,
353			 "illegal xattr request %s (only user namespace supported)\n",
354			 ea_name);
355
356	/* We could add an additional check for streams ie
357	    if proc/fs/cifs/streamstoxattr is set then
358		search server for EAs or streams to
359		returns as xattrs */
360
361	if (rc == -EINVAL)
362		rc = -EOPNOTSUPP;
363
364get_ea_exit:
365	kfree(full_path);
366	free_xid(xid);
367	cifs_put_tlink(tlink);
368#endif
369	return rc;
370}
371
372ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
373{
374	ssize_t rc = -EOPNOTSUPP;
375#ifdef CONFIG_CIFS_XATTR
376	unsigned int xid;
377	struct cifs_sb_info *cifs_sb;
378	struct tcon_link *tlink;
379	struct cifs_tcon *pTcon;
380	struct super_block *sb;
381	char *full_path;
382
383	if (direntry == NULL)
384		return -EIO;
385	if (d_really_is_negative(direntry))
386		return -EIO;
387	sb = d_inode(direntry)->i_sb;
388	if (sb == NULL)
389		return -EIO;
390
391	cifs_sb = CIFS_SB(sb);
392	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
393		return -EOPNOTSUPP;
394
395	tlink = cifs_sb_tlink(cifs_sb);
396	if (IS_ERR(tlink))
397		return PTR_ERR(tlink);
398	pTcon = tlink_tcon(tlink);
399
400	xid = get_xid();
401
402	full_path = build_path_from_dentry(direntry);
403	if (full_path == NULL) {
404		rc = -ENOMEM;
405		goto list_ea_exit;
406	}
407	/* return dos attributes as pseudo xattr */
408	/* return alt name if available as pseudo attr */
409
410	/* if proc/fs/cifs/streamstoxattr is set then
411		search server for EAs or streams to
412		returns as xattrs */
413
414	if (pTcon->ses->server->ops->query_all_EAs)
415		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
416				full_path, NULL, data, buf_size,
417				cifs_sb->local_nls, cifs_remap(cifs_sb));
418list_ea_exit:
419	kfree(full_path);
420	free_xid(xid);
421	cifs_put_tlink(tlink);
422#endif
423	return rc;
424}
425