[PATCH] knfsd: close a race-opportunity in d_splice_alias
[linux-2.6] / fs / cifs / xattr.c
1 /*
2  *   fs/cifs/xattr.c
3  *
4  *   Copyright (c) International Business Machines  Corp., 2003
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 "cifsfs.h"
25 #include "cifspdu.h"
26 #include "cifsglob.h"
27 #include "cifsproto.h"
28 #include "cifs_debug.h"
29
30 #define MAX_EA_VALUE_SIZE 65535
31 #define CIFS_XATTR_DOS_ATTRIB "user.DosAttrib"
32 #define CIFS_XATTR_USER_PREFIX "user."
33 #define CIFS_XATTR_SYSTEM_PREFIX "system."
34 #define CIFS_XATTR_OS2_PREFIX "os2."
35 #define CIFS_XATTR_SECURITY_PREFIX ".security"
36 #define CIFS_XATTR_TRUSTED_PREFIX "trusted."
37 #define XATTR_TRUSTED_PREFIX_LEN  8
38 #define XATTR_SECURITY_PREFIX_LEN 9
39 /* BB need to add server (Samba e.g) support for security and trusted prefix */
40   
41
42
43 int cifs_removexattr(struct dentry * direntry, const char * ea_name)
44 {
45         int rc = -EOPNOTSUPP;
46 #ifdef CONFIG_CIFS_XATTR
47         int xid;
48         struct cifs_sb_info *cifs_sb;
49         struct cifsTconInfo *pTcon;
50         struct super_block * sb;
51         char * full_path;
52                                                                                      
53         if(direntry == NULL)
54                 return -EIO;
55         if(direntry->d_inode == NULL)
56                 return -EIO;
57         sb = direntry->d_inode->i_sb;
58         if(sb == NULL)
59                 return -EIO;
60         xid = GetXid();
61                                                                                      
62         cifs_sb = CIFS_SB(sb);
63         pTcon = cifs_sb->tcon;
64                                                                                      
65         full_path = build_path_from_dentry(direntry);
66         if(full_path == NULL) {
67                 FreeXid(xid);
68                 return -ENOMEM;
69         }
70         if(ea_name == NULL) {
71                 cFYI(1,("Null xattr names not supported"));
72         } else if(strncmp(ea_name,CIFS_XATTR_USER_PREFIX,5)
73                 && (strncmp(ea_name,CIFS_XATTR_OS2_PREFIX,4))) {
74                 cFYI(1,("illegal xattr namespace %s (only user namespace supported)",ea_name));
75                 /* BB what if no namespace prefix? */
76                 /* Should we just pass them to server, except for
77                 system and perhaps security prefixes? */
78         } else {
79                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
80                         goto remove_ea_exit;
81
82                 ea_name+=5; /* skip past user. prefix */
83                 rc = CIFSSMBSetEA(xid,pTcon,full_path,ea_name,NULL,
84                         (__u16)0, cifs_sb->local_nls,
85                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
86         }
87 remove_ea_exit:
88         kfree(full_path);
89         FreeXid(xid);
90 #endif
91         return rc;
92 }
93
94 int cifs_setxattr(struct dentry * direntry, const char * ea_name,
95         const void * ea_value, size_t value_size, int flags)
96 {
97         int rc = -EOPNOTSUPP;
98 #ifdef CONFIG_CIFS_XATTR
99         int xid;
100         struct cifs_sb_info *cifs_sb;
101         struct cifsTconInfo *pTcon;
102         struct super_block * sb;
103         char * full_path;
104
105         if(direntry == NULL)
106                 return -EIO;
107         if(direntry->d_inode == NULL)
108                 return -EIO;
109         sb = direntry->d_inode->i_sb;
110         if(sb == NULL)
111                 return -EIO;
112         xid = GetXid();
113
114         cifs_sb = CIFS_SB(sb);
115         pTcon = cifs_sb->tcon;
116
117         full_path = build_path_from_dentry(direntry);
118         if(full_path == NULL) {
119                 FreeXid(xid);
120                 return -ENOMEM;
121         }
122         /* return dos attributes as pseudo xattr */
123         /* return alt name if available as pseudo attr */
124
125         /* if proc/fs/cifs/streamstoxattr is set then
126                 search server for EAs or streams to 
127                 returns as xattrs */
128         if(value_size > MAX_EA_VALUE_SIZE) {
129                 cFYI(1,("size of EA value too large"));
130                 kfree(full_path);
131                 FreeXid(xid);
132                 return -EOPNOTSUPP;
133         }
134
135         if(ea_name == NULL) {
136                 cFYI(1,("Null xattr names not supported"));
137         } else if(strncmp(ea_name,CIFS_XATTR_USER_PREFIX,5) == 0) {
138                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
139                         goto set_ea_exit;
140                 if(strncmp(ea_name,CIFS_XATTR_DOS_ATTRIB,14) == 0) {
141                         cFYI(1,("attempt to set cifs inode metadata"));
142                 }
143                 ea_name += 5; /* skip past user. prefix */
144                 rc = CIFSSMBSetEA(xid,pTcon,full_path,ea_name,ea_value,
145                         (__u16)value_size, cifs_sb->local_nls,
146                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
147         } else if(strncmp(ea_name, CIFS_XATTR_OS2_PREFIX,4) == 0) {
148                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
149                         goto set_ea_exit;
150
151                 ea_name += 4; /* skip past os2. prefix */
152                 rc = CIFSSMBSetEA(xid,pTcon,full_path,ea_name,ea_value,
153                         (__u16)value_size, cifs_sb->local_nls,
154                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
155         } else {
156                 int temp; 
157                 temp = strncmp(ea_name,POSIX_ACL_XATTR_ACCESS,
158                         strlen(POSIX_ACL_XATTR_ACCESS));
159                 if (temp == 0) {
160 #ifdef CONFIG_CIFS_POSIX
161                         if(sb->s_flags & MS_POSIXACL)
162                                 rc = CIFSSMBSetPosixACL(xid, pTcon,full_path,
163                                         ea_value, (const int)value_size, 
164                                         ACL_TYPE_ACCESS,cifs_sb->local_nls,
165                                         cifs_sb->mnt_cifs_flags & 
166                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
167                         cFYI(1,("set POSIX ACL rc %d",rc));
168 #else
169                         cFYI(1,("set POSIX ACL not supported"));
170 #endif
171                 } else if(strncmp(ea_name,POSIX_ACL_XATTR_DEFAULT,strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {
172 #ifdef CONFIG_CIFS_POSIX
173                         if(sb->s_flags & MS_POSIXACL)
174                                 rc = CIFSSMBSetPosixACL(xid, pTcon,full_path,
175                                         ea_value, (const int)value_size, 
176                                         ACL_TYPE_DEFAULT, cifs_sb->local_nls,
177                                         cifs_sb->mnt_cifs_flags & 
178                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
179                         cFYI(1,("set POSIX default ACL rc %d",rc));
180 #else
181                         cFYI(1,("set default POSIX ACL not supported"));
182 #endif
183                 } else {
184                         cFYI(1,("illegal xattr request %s (only user namespace supported)",ea_name));
185                   /* BB what if no namespace prefix? */
186                   /* Should we just pass them to server, except for 
187                   system and perhaps security prefixes? */
188                 }
189         }
190
191 set_ea_exit:
192         kfree(full_path);
193         FreeXid(xid);
194 #endif
195         return rc;
196 }
197
198 ssize_t cifs_getxattr(struct dentry * direntry, const char * ea_name,
199          void * ea_value, size_t buf_size)
200 {
201         ssize_t rc = -EOPNOTSUPP;
202 #ifdef CONFIG_CIFS_XATTR
203         int xid;
204         struct cifs_sb_info *cifs_sb;
205         struct cifsTconInfo *pTcon;
206         struct super_block * sb;
207         char * full_path;
208
209         if(direntry == NULL)
210                 return -EIO;
211         if(direntry->d_inode == NULL)
212                 return -EIO;
213         sb = direntry->d_inode->i_sb;
214         if(sb == NULL)
215                 return -EIO;
216
217         xid = GetXid();
218
219         cifs_sb = CIFS_SB(sb);
220         pTcon = cifs_sb->tcon;
221
222         full_path = build_path_from_dentry(direntry);
223         if(full_path == NULL) {
224                 FreeXid(xid);
225                 return -ENOMEM;
226         }
227         /* return dos attributes as pseudo xattr */
228         /* return alt name if available as pseudo attr */
229         if(ea_name == NULL) {
230                 cFYI(1,("Null xattr names not supported"));
231         } else if(strncmp(ea_name,CIFS_XATTR_USER_PREFIX,5) == 0) {
232                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
233                         goto get_ea_exit;
234
235                 if(strncmp(ea_name,CIFS_XATTR_DOS_ATTRIB,14) == 0) {
236                         cFYI(1,("attempt to query cifs inode metadata"));
237                         /* revalidate/getattr then populate from inode */
238                 } /* BB add else when above is implemented */
239                 ea_name += 5; /* skip past user. prefix */
240                 rc = CIFSSMBQueryEA(xid,pTcon,full_path,ea_name,ea_value,
241                         buf_size, cifs_sb->local_nls,
242                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
243         } else if(strncmp(ea_name, CIFS_XATTR_OS2_PREFIX,4) == 0) {
244                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
245                         goto get_ea_exit;
246
247                 ea_name += 4; /* skip past os2. prefix */
248                 rc = CIFSSMBQueryEA(xid,pTcon,full_path,ea_name,ea_value,
249                         buf_size, cifs_sb->local_nls,
250                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
251         } else if(strncmp(ea_name,POSIX_ACL_XATTR_ACCESS,
252                           strlen(POSIX_ACL_XATTR_ACCESS)) == 0) {
253 #ifdef CONFIG_CIFS_POSIX
254                 if(sb->s_flags & MS_POSIXACL)
255                         rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
256                                 ea_value, buf_size, ACL_TYPE_ACCESS, 
257                                 cifs_sb->local_nls,
258                                 cifs_sb->mnt_cifs_flags & 
259                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
260 /*              else if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
261                         __u16 fid;
262                         int oplock = FALSE;
263                         rc = CIFSSMBOpen(xid, pTcon, full_path,
264                                          FILE_OPEN, GENERIC_READ, 0, &fid,
265                                          &oplock, NULL, cifs_sb->local_nls,
266                                          cifs_sb->mnt_cifs_flags &
267                                          CIFS_MOUNT_MAP_SPECIAL_CHR);
268                         if(rc == 0) {
269                                 rc = CIFSSMBGetCIFSACL(xid, pTcon, fid,
270                                         ea_value, buf_size,
271                                         ACL_TYPE_ACCESS);
272                                 CIFSSMBClose(xid, pTcon, fid);
273                         }
274                 } */  /* BB enable after fixing up return data */
275                                 
276 #else 
277                 cFYI(1,("query POSIX ACL not supported yet"));
278 #endif /* CONFIG_CIFS_POSIX */
279         } else if(strncmp(ea_name,POSIX_ACL_XATTR_DEFAULT,
280                           strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {
281 #ifdef CONFIG_CIFS_POSIX
282                 if(sb->s_flags & MS_POSIXACL)
283                         rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
284                                 ea_value, buf_size, ACL_TYPE_DEFAULT, 
285                                 cifs_sb->local_nls,
286                                 cifs_sb->mnt_cifs_flags & 
287                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
288 #else 
289                 cFYI(1,("query POSIX default ACL not supported yet"));
290 #endif
291         } else if(strncmp(ea_name,
292                   CIFS_XATTR_TRUSTED_PREFIX,XATTR_TRUSTED_PREFIX_LEN) == 0) {
293                 cFYI(1,("Trusted xattr namespace not supported yet"));
294         } else if(strncmp(ea_name,
295                   CIFS_XATTR_SECURITY_PREFIX,XATTR_SECURITY_PREFIX_LEN) == 0) {
296                 cFYI(1,("Security xattr namespace not supported yet"));
297         } else {
298                 cFYI(1,("illegal xattr name request %s (only user namespace supported)",ea_name));
299         }
300
301         /* We could add an additional check for streams ie 
302             if proc/fs/cifs/streamstoxattr is set then
303                 search server for EAs or streams to 
304                 returns as xattrs */
305
306         if(rc == -EINVAL)
307                 rc = -EOPNOTSUPP; 
308
309 get_ea_exit:
310         kfree(full_path);
311         FreeXid(xid);
312 #endif
313         return rc;
314 }
315
316 ssize_t cifs_listxattr(struct dentry * direntry, char * data, size_t buf_size)
317 {
318         ssize_t rc = -EOPNOTSUPP;
319 #ifdef CONFIG_CIFS_XATTR
320         int xid;
321         struct cifs_sb_info *cifs_sb;
322         struct cifsTconInfo *pTcon;
323         struct super_block * sb;
324         char * full_path;
325
326         if(direntry == NULL)
327                 return -EIO;
328         if(direntry->d_inode == NULL)
329                 return -EIO;
330         sb = direntry->d_inode->i_sb;
331         if(sb == NULL)
332                 return -EIO;
333
334         cifs_sb = CIFS_SB(sb);
335         pTcon = cifs_sb->tcon;
336
337         if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
338                 return -EOPNOTSUPP;
339
340         xid = GetXid();
341
342         full_path = build_path_from_dentry(direntry);
343         if(full_path == NULL) {
344                 FreeXid(xid);
345                 return -ENOMEM;
346         }
347         /* return dos attributes as pseudo xattr */
348         /* return alt name if available as pseudo attr */
349
350         /* if proc/fs/cifs/streamstoxattr is set then
351                 search server for EAs or streams to 
352                 returns as xattrs */
353         rc = CIFSSMBQAllEAs(xid,pTcon,full_path,data,buf_size,
354                                 cifs_sb->local_nls,
355                                 cifs_sb->mnt_cifs_flags & 
356                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
357
358         kfree(full_path);
359         FreeXid(xid);
360 #endif
361         return rc;
362 }