fs/cifs/xattr.c

   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 "cifsfs.h"
  26 #include "cifspdu.h"
  27 #include "cifsglob.h"
  28 #include "cifsproto.h"
  29 #include "cifs_debug.h"
  30
  31 #define MAX_EA_VALUE_SIZE 65535
  32 #define CIFS_XATTR_DOS_ATTRIB "user.DosAttrib"
  33 #define CIFS_XATTR_USER_PREFIX "user."
  34 #define CIFS_XATTR_SYSTEM_PREFIX "system."
  35 #define CIFS_XATTR_OS2_PREFIX "os2."
  36 #define CIFS_XATTR_SECURITY_PREFIX ".security"
  37 #define CIFS_XATTR_TRUSTED_PREFIX "trusted."
  38 #define XATTR_TRUSTED_PREFIX_LEN  8
  39 #define XATTR_SECURITY_PREFIX_LEN 9
  40 /* BB need to add server (Samba e.g) support for security and trusted prefix */
  41
  42
  43
  44 int cifs_removexattr(struct dentry *direntry, const char *ea_name)
  45 {
  46         int rc = -EOPNOTSUPP;
  47 #ifdef CONFIG_CIFS_XATTR
  48         int xid;
  49         struct cifs_sb_info *cifs_sb;
  50         struct cifsTconInfo *pTcon;
  51         struct super_block *sb;
  52         char *full_path;
  53
  54         if (direntry == NULL)
  55                 return -EIO;
  56         if (direntry->d_inode == NULL)
  57                 return -EIO;
  58         sb = direntry->d_inode->i_sb;
  59         if (sb == NULL)
  60                 return -EIO;
  61         xid = GetXid();
  62
  63         cifs_sb = CIFS_SB(sb);
  64         pTcon = cifs_sb->tcon;
  65
  66         full_path = build_path_from_dentry(direntry);
  67         if (full_path == NULL) {
  68                 rc = -ENOMEM;
  69                 FreeXid(xid);
  70                 return rc;
  71         }
  72         if (ea_name == NULL) {
  73                 cFYI(1, "Null xattr names not supported");
  74         } else if (strncmp(ea_name, CIFS_XATTR_USER_PREFIX, 5)
  75                 && (strncmp(ea_name, CIFS_XATTR_OS2_PREFIX, 4))) {
  76                 cFYI(1,
  77                      "illegal xattr request %s (only user namespace supported)",
  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 += 5; /* skip past user. prefix */
  87                 rc = CIFSSMBSetEA(xid, pTcon, full_path, ea_name, NULL,
  88                         (__u16)0, cifs_sb->local_nls,
  89                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
  90         }
  91 remove_ea_exit:
  92         kfree(full_path);
  93         FreeXid(xid);
  94 #endif
  95         return rc;
  96 }
  97
  98 int cifs_setxattr(struct dentry *direntry, const char *ea_name,
  99                   const void *ea_value, size_t value_size, int flags)
 100 {
 101         int rc = -EOPNOTSUPP;
 102 #ifdef CONFIG_CIFS_XATTR
 103         int xid;
 104         struct cifs_sb_info *cifs_sb;
 105         struct cifsTconInfo *pTcon;
 106         struct super_block *sb;
 107         char *full_path;
 108
 109         if (direntry == NULL)
 110                 return -EIO;
 111         if (direntry->d_inode == NULL)
 112                 return -EIO;
 113         sb = direntry->d_inode->i_sb;
 114         if (sb == NULL)
 115                 return -EIO;
 116         xid = GetXid();
 117
 118         cifs_sb = CIFS_SB(sb);
 119         pTcon = cifs_sb->tcon;
 120
 121         full_path = build_path_from_dentry(direntry);
 122         if (full_path == NULL) {
 123                 rc = -ENOMEM;
 124                 FreeXid(xid);
 125                 return rc;
 126         }
 127         /* return dos attributes as pseudo xattr */
 128         /* return alt name if available as pseudo attr */
 129
 130         /* if proc/fs/cifs/streamstoxattr is set then
 131                 search server for EAs or streams to
 132                 returns as xattrs */
 133         if (value_size > MAX_EA_VALUE_SIZE) {
 134                 cFYI(1, "size of EA value too large");
 135                 kfree(full_path);
 136                 FreeXid(xid);
 137                 return -EOPNOTSUPP;
 138         }
 139
 140         if (ea_name == NULL) {
 141                 cFYI(1, "Null xattr names not supported");
 142         } else if (strncmp(ea_name, CIFS_XATTR_USER_PREFIX, 5) == 0) {
 143                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 144                         goto set_ea_exit;
 145                 if (strncmp(ea_name, CIFS_XATTR_DOS_ATTRIB, 14) == 0)
 146                         cFYI(1, "attempt to set cifs inode metadata");
 147
 148                 ea_name += 5; /* skip past user. prefix */
 149                 rc = CIFSSMBSetEA(xid, pTcon, full_path, ea_name, ea_value,
 150                         (__u16)value_size, cifs_sb->local_nls,
 151                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 152         } else if (strncmp(ea_name, CIFS_XATTR_OS2_PREFIX, 4) == 0) {
 153                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 154                         goto set_ea_exit;
 155
 156                 ea_name += 4; /* skip past os2. prefix */
 157                 rc = CIFSSMBSetEA(xid, pTcon, full_path, ea_name, ea_value,
 158                         (__u16)value_size, cifs_sb->local_nls,
 159                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 160         } else {
 161                 int temp;
 162                 temp = strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,
 163                         strlen(POSIX_ACL_XATTR_ACCESS));
 164                 if (temp == 0) {
 165 #ifdef CONFIG_CIFS_POSIX
 166                         if (sb->s_flags & MS_POSIXACL)
 167                                 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 168                                         ea_value, (const int)value_size,
 169                                         ACL_TYPE_ACCESS, cifs_sb->local_nls,
 170                                         cifs_sb->mnt_cifs_flags &
 171                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 172                         cFYI(1, "set POSIX ACL rc %d", rc);
 173 #else
 174                         cFYI(1, "set POSIX ACL not supported");
 175 #endif
 176                 } else if (strncmp(ea_name, POSIX_ACL_XATTR_DEFAULT,
 177                                    strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {
 178 #ifdef CONFIG_CIFS_POSIX
 179                         if (sb->s_flags & MS_POSIXACL)
 180                                 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 181                                         ea_value, (const int)value_size,
 182                                         ACL_TYPE_DEFAULT, cifs_sb->local_nls,
 183                                         cifs_sb->mnt_cifs_flags &
 184                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 185                         cFYI(1, "set POSIX default ACL rc %d", rc);
 186 #else
 187                         cFYI(1, "set default POSIX ACL not supported");
 188 #endif
 189                 } else {
 190                         cFYI(1, "illegal xattr request %s (only user namespace"
 191                                 " supported)", ea_name);
 192                   /* BB what if no namespace prefix? */
 193                   /* Should we just pass them to server, except for
 194                   system and perhaps security prefixes? */
 195                 }
 196         }
 197
 198 set_ea_exit:
 199         kfree(full_path);
 200         FreeXid(xid);
 201 #endif
 202         return rc;
 203 }
 204
 205 ssize_t cifs_getxattr(struct dentry *direntry, const char *ea_name,
 206         void *ea_value, size_t buf_size)
 207 {
 208         ssize_t rc = -EOPNOTSUPP;
 209 #ifdef CONFIG_CIFS_XATTR
 210         int xid;
 211         struct cifs_sb_info *cifs_sb;
 212         struct cifsTconInfo *pTcon;
 213         struct super_block *sb;
 214         char *full_path;
 215
 216         if (direntry == NULL)
 217                 return -EIO;
 218         if (direntry->d_inode == NULL)
 219                 return -EIO;
 220         sb = direntry->d_inode->i_sb;
 221         if (sb == NULL)
 222                 return -EIO;
 223
 224         xid = GetXid();
 225
 226         cifs_sb = CIFS_SB(sb);
 227         pTcon = cifs_sb->tcon;
 228
 229         full_path = build_path_from_dentry(direntry);
 230         if (full_path == NULL) {
 231                 rc = -ENOMEM;
 232                 FreeXid(xid);
 233                 return rc;
 234         }
 235         /* return dos attributes as pseudo xattr */
 236         /* return alt name if available as pseudo attr */
 237         if (ea_name == NULL) {
 238                 cFYI(1, "Null xattr names not supported");
 239         } else if (strncmp(ea_name, CIFS_XATTR_USER_PREFIX, 5) == 0) {
 240                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 241                         goto get_ea_exit;
 242
 243                 if (strncmp(ea_name, CIFS_XATTR_DOS_ATTRIB, 14) == 0) {
 244                         cFYI(1, "attempt to query cifs inode metadata");
 245                         /* revalidate/getattr then populate from inode */
 246                 } /* BB add else when above is implemented */
 247                 ea_name += 5; /* skip past user. prefix */
 248                 rc = CIFSSMBQAllEAs(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, CIFS_XATTR_OS2_PREFIX, 4) == 0) {
 252                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 253                         goto get_ea_exit;
 254
 255                 ea_name += 4; /* skip past os2. prefix */
 256                 rc = CIFSSMBQAllEAs(xid, pTcon, full_path, ea_name, ea_value,
 257                         buf_size, cifs_sb->local_nls,
 258                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 259         } else if (strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,
 260                           strlen(POSIX_ACL_XATTR_ACCESS)) == 0) {
 261 #ifdef CONFIG_CIFS_POSIX
 262                 if (sb->s_flags & MS_POSIXACL)
 263                         rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
 264                                 ea_value, buf_size, ACL_TYPE_ACCESS,
 265                                 cifs_sb->local_nls,
 266                                 cifs_sb->mnt_cifs_flags &
 267                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 268 #ifdef CONFIG_CIFS_EXPERIMENTAL
 269                 else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
 270                         __u16 fid;
 271                         int oplock = 0;
 272                         struct cifs_ntsd *pacl = NULL;
 273                         __u32 buflen = 0;
 274                         if (experimEnabled)
 275                                 rc = CIFSSMBOpen(xid, pTcon, full_path,
 276                                         FILE_OPEN, GENERIC_READ, 0, &fid,
 277                                         &oplock, NULL, cifs_sb->local_nls,
 278                                         cifs_sb->mnt_cifs_flags &
 279                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 280                         /* else rc is EOPNOTSUPP from above */
 281
 282                         if (rc == 0) {
 283                                 rc = CIFSSMBGetCIFSACL(xid, pTcon, fid, &pacl,
 284                                                       &buflen);
 285                                 CIFSSMBClose(xid, pTcon, fid);
 286                         }
 287                 }
 288 #endif /* EXPERIMENTAL */
 289 #else
 290                 cFYI(1, "query POSIX ACL not supported yet");
 291 #endif /* CONFIG_CIFS_POSIX */
 292         } else if (strncmp(ea_name, POSIX_ACL_XATTR_DEFAULT,
 293                           strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {
 294 #ifdef CONFIG_CIFS_POSIX
 295                 if (sb->s_flags & MS_POSIXACL)
 296                         rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
 297                                 ea_value, buf_size, ACL_TYPE_DEFAULT,
 298                                 cifs_sb->local_nls,
 299                                 cifs_sb->mnt_cifs_flags &
 300                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 301 #else
 302                 cFYI(1, "query POSIX default ACL not supported yet");
 303 #endif
 304         } else if (strncmp(ea_name,
 305                   CIFS_XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) == 0) {
 306                 cFYI(1, "Trusted xattr namespace not supported yet");
 307         } else if (strncmp(ea_name,
 308                   CIFS_XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) == 0) {
 309                 cFYI(1, "Security xattr namespace not supported yet");
 310         } else
 311                 cFYI(1,
 312                     "illegal xattr request %s (only user namespace supported)",
 313                      ea_name);
 314
 315         /* We could add an additional check for streams ie
 316             if proc/fs/cifs/streamstoxattr is set then
 317                 search server for EAs or streams to
 318                 returns as xattrs */
 319
 320         if (rc == -EINVAL)
 321                 rc = -EOPNOTSUPP;
 322
 323 get_ea_exit:
 324         kfree(full_path);
 325         FreeXid(xid);
 326 #endif
 327         return rc;
 328 }
 329
 330 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
 331 {
 332         ssize_t rc = -EOPNOTSUPP;
 333 #ifdef CONFIG_CIFS_XATTR
 334         int xid;
 335         struct cifs_sb_info *cifs_sb;
 336         struct cifsTconInfo *pTcon;
 337         struct super_block *sb;
 338         char *full_path;
 339
 340         if (direntry == NULL)
 341                 return -EIO;
 342         if (direntry->d_inode == NULL)
 343                 return -EIO;
 344         sb = direntry->d_inode->i_sb;
 345         if (sb == NULL)
 346                 return -EIO;
 347
 348         cifs_sb = CIFS_SB(sb);
 349         pTcon = cifs_sb->tcon;
 350
 351         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 352                 return -EOPNOTSUPP;
 353
 354         xid = GetXid();
 355
 356         full_path = build_path_from_dentry(direntry);
 357         if (full_path == NULL) {
 358                 rc = -ENOMEM;
 359                 FreeXid(xid);
 360                 return rc;
 361         }
 362         /* return dos attributes as pseudo xattr */
 363         /* return alt name if available as pseudo attr */
 364
 365         /* if proc/fs/cifs/streamstoxattr is set then
 366                 search server for EAs or streams to
 367                 returns as xattrs */
 368         rc = CIFSSMBQAllEAs(xid, pTcon, full_path, NULL, data,
 369                                 buf_size, cifs_sb->local_nls,
 370                                 cifs_sb->mnt_cifs_flags &
 371                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 372
 373         kfree(full_path);
 374         FreeXid(xid);
 375 #endif
 376         return rc;
 377 }