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_CIFS_ACL "system.cifs_acl"
  34 #define CIFS_XATTR_USER_PREFIX "user."
  35 #define CIFS_XATTR_SYSTEM_PREFIX "system."
  36 #define CIFS_XATTR_OS2_PREFIX "os2."
  37 #define CIFS_XATTR_SECURITY_PREFIX "security."
  38 #define CIFS_XATTR_TRUSTED_PREFIX "trusted."
  39 #define XATTR_TRUSTED_PREFIX_LEN  8
  40 #define XATTR_SECURITY_PREFIX_LEN 9
  41 /* BB need to add server (Samba e.g) support for security and trusted prefix */
  42
  43
  44
  45 int cifs_removexattr(struct dentry *direntry, const char *ea_name)
  46 {
  47         int rc = -EOPNOTSUPP;
  48 #ifdef CONFIG_CIFS_XATTR
  49         int xid;
  50         struct cifs_sb_info *cifs_sb;
  51         struct tcon_link *tlink;
  52         struct cifsTconInfo *pTcon;
  53         struct super_block *sb;
  54         char *full_path = NULL;
  55
  56         if (direntry == NULL)
  57                 return -EIO;
  58         if (direntry->d_inode == NULL)
  59                 return -EIO;
  60         sb = direntry->d_inode->i_sb;
  61         if (sb == NULL)
  62                 return -EIO;
  63
  64         cifs_sb = CIFS_SB(sb);
  65         tlink = cifs_sb_tlink(cifs_sb);
  66         if (IS_ERR(tlink))
  67                 return PTR_ERR(tlink);
  68         pTcon = tlink_tcon(tlink);
  69
  70         xid = GetXid();
  71
  72         full_path = build_path_from_dentry(direntry);
  73         if (full_path == NULL) {
  74                 rc = -ENOMEM;
  75                 goto remove_ea_exit;
  76         }
  77         if (ea_name == NULL) {
  78                 cFYI(1, "Null xattr names not supported");
  79         } else if (strncmp(ea_name, CIFS_XATTR_USER_PREFIX, 5)
  80                 && (strncmp(ea_name, CIFS_XATTR_OS2_PREFIX, 4))) {
  81                 cFYI(1,
  82                      "illegal xattr request %s (only user namespace supported)",
  83                      ea_name);
  84                 /* BB what if no namespace prefix? */
  85                 /* Should we just pass them to server, except for
  86                 system and perhaps security prefixes? */
  87         } else {
  88                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
  89                         goto remove_ea_exit;
  90
  91                 ea_name += 5; /* skip past user. prefix */
  92                 rc = CIFSSMBSetEA(xid, pTcon, full_path, ea_name, NULL,
  93                         (__u16)0, cifs_sb->local_nls,
  94                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
  95         }
  96 remove_ea_exit:
  97         kfree(full_path);
  98         FreeXid(xid);
  99         cifs_put_tlink(tlink);
 100 #endif
 101         return rc;
 102 }
 103
 104 int cifs_setxattr(struct dentry *direntry, const char *ea_name,
 105                   const void *ea_value, size_t value_size, int flags)
 106 {
 107         int rc = -EOPNOTSUPP;
 108 #ifdef CONFIG_CIFS_XATTR
 109         int xid;
 110         struct cifs_sb_info *cifs_sb;
 111         struct tcon_link *tlink;
 112         struct cifsTconInfo *pTcon;
 113         struct super_block *sb;
 114         char *full_path;
 115         struct cifs_ntsd *pacl;
 116
 117         if (direntry == NULL)
 118                 return -EIO;
 119         if (direntry->d_inode == NULL)
 120                 return -EIO;
 121         sb = direntry->d_inode->i_sb;
 122         if (sb == NULL)
 123                 return -EIO;
 124
 125         cifs_sb = CIFS_SB(sb);
 126         tlink = cifs_sb_tlink(cifs_sb);
 127         if (IS_ERR(tlink))
 128                 return PTR_ERR(tlink);
 129         pTcon = tlink_tcon(tlink);
 130
 131         xid = GetXid();
 132
 133         full_path = build_path_from_dentry(direntry);
 134         if (full_path == NULL) {
 135                 rc = -ENOMEM;
 136                 goto set_ea_exit;
 137         }
 138         /* return dos attributes as pseudo xattr */
 139         /* return alt name if available as pseudo attr */
 140
 141         /* if proc/fs/cifs/streamstoxattr is set then
 142                 search server for EAs or streams to
 143                 returns as xattrs */
 144         if (value_size > MAX_EA_VALUE_SIZE) {
 145                 cFYI(1, "size of EA value too large");
 146                 rc = -EOPNOTSUPP;
 147                 goto set_ea_exit;
 148         }
 149
 150         if (ea_name == NULL) {
 151                 cFYI(1, "Null xattr names not supported");
 152         } else if (strncmp(ea_name, CIFS_XATTR_USER_PREFIX, 5) == 0) {
 153                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 154                         goto set_ea_exit;
 155                 if (strncmp(ea_name, CIFS_XATTR_DOS_ATTRIB, 14) == 0)
 156                         cFYI(1, "attempt to set cifs inode metadata");
 157
 158                 ea_name += 5; /* skip past user. prefix */
 159                 rc = CIFSSMBSetEA(xid, pTcon, full_path, ea_name, ea_value,
 160                         (__u16)value_size, cifs_sb->local_nls,
 161                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 162         } else if (strncmp(ea_name, CIFS_XATTR_OS2_PREFIX, 4) == 0) {
 163                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 164                         goto set_ea_exit;
 165
 166                 ea_name += 4; /* skip past os2. prefix */
 167                 rc = CIFSSMBSetEA(xid, pTcon, full_path, ea_name, ea_value,
 168                         (__u16)value_size, cifs_sb->local_nls,
 169                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 170         } else if (strncmp(ea_name, CIFS_XATTR_CIFS_ACL,
 171                         strlen(CIFS_XATTR_CIFS_ACL)) == 0) {
 172                 pacl = kmalloc(value_size, GFP_KERNEL);
 173                 if (!pacl) {
 174                         cFYI(1, "%s: Can't allocate memory for ACL",
 175                                         __func__);
 176                         rc = -ENOMEM;
 177                 } else {
 178 #ifdef CONFIG_CIFS_ACL
 179                         memcpy(pacl, ea_value, value_size);
 180                         rc = set_cifs_acl(pacl, value_size,
 181                                 direntry->d_inode, full_path);
 182                         if (rc == 0) /* force revalidate of the inode */
 183                                 CIFS_I(direntry->d_inode)->time = 0;
 184                         kfree(pacl);
 185 #else
 186                         cFYI(1, "Set CIFS ACL not supported yet");
 187 #endif /* CONFIG_CIFS_ACL */
 188                 }
 189         } else {
 190                 int temp;
 191                 temp = strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,
 192                         strlen(POSIX_ACL_XATTR_ACCESS));
 193                 if (temp == 0) {
 194 #ifdef CONFIG_CIFS_POSIX
 195                         if (sb->s_flags & MS_POSIXACL)
 196                                 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 197                                         ea_value, (const int)value_size,
 198                                         ACL_TYPE_ACCESS, cifs_sb->local_nls,
 199                                         cifs_sb->mnt_cifs_flags &
 200                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 201                         cFYI(1, "set POSIX ACL rc %d", rc);
 202 #else
 203                         cFYI(1, "set POSIX ACL not supported");
 204 #endif
 205                 } else if (strncmp(ea_name, POSIX_ACL_XATTR_DEFAULT,
 206                                    strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {
 207 #ifdef CONFIG_CIFS_POSIX
 208                         if (sb->s_flags & MS_POSIXACL)
 209                                 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 210                                         ea_value, (const int)value_size,
 211                                         ACL_TYPE_DEFAULT, cifs_sb->local_nls,
 212                                         cifs_sb->mnt_cifs_flags &
 213                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 214                         cFYI(1, "set POSIX default ACL rc %d", rc);
 215 #else
 216                         cFYI(1, "set default POSIX ACL not supported");
 217 #endif
 218                 } else {
 219                         cFYI(1, "illegal xattr request %s (only user namespace"
 220                                 " supported)", 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
 227 set_ea_exit:
 228         kfree(full_path);
 229         FreeXid(xid);
 230         cifs_put_tlink(tlink);
 231 #endif
 232         return rc;
 233 }
 234
 235 ssize_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         int xid;
 241         struct cifs_sb_info *cifs_sb;
 242         struct tcon_link *tlink;
 243         struct cifsTconInfo *pTcon;
 244         struct super_block *sb;
 245         char *full_path;
 246
 247         if (direntry == NULL)
 248                 return -EIO;
 249         if (direntry->d_inode == NULL)
 250                 return -EIO;
 251         sb = direntry->d_inode->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 = GetXid();
 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                 cFYI(1, "Null xattr names not supported");
 272         } else if (strncmp(ea_name, CIFS_XATTR_USER_PREFIX, 5) == 0) {
 273                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 274                         goto get_ea_exit;
 275
 276                 if (strncmp(ea_name, CIFS_XATTR_DOS_ATTRIB, 14) == 0) {
 277                         cFYI(1, "attempt to query cifs inode metadata");
 278                         /* revalidate/getattr then populate from inode */
 279                 } /* BB add else when above is implemented */
 280                 ea_name += 5; /* skip past user. prefix */
 281                 rc = CIFSSMBQAllEAs(xid, pTcon, full_path, ea_name, ea_value,
 282                         buf_size, cifs_sb->local_nls,
 283                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 284         } else if (strncmp(ea_name, CIFS_XATTR_OS2_PREFIX, 4) == 0) {
 285                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 286                         goto get_ea_exit;
 287
 288                 ea_name += 4; /* skip past os2. prefix */
 289                 rc = CIFSSMBQAllEAs(xid, pTcon, full_path, ea_name, ea_value,
 290                         buf_size, cifs_sb->local_nls,
 291                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 292         } else if (strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,
 293                           strlen(POSIX_ACL_XATTR_ACCESS)) == 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_ACCESS,
 298                                 cifs_sb->local_nls,
 299                                 cifs_sb->mnt_cifs_flags &
 300                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 301 #else
 302                 cFYI(1, "Query POSIX ACL not supported yet");
 303 #endif /* CONFIG_CIFS_POSIX */
 304         } else if (strncmp(ea_name, POSIX_ACL_XATTR_DEFAULT,
 305                           strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {
 306 #ifdef CONFIG_CIFS_POSIX
 307                 if (sb->s_flags & MS_POSIXACL)
 308                         rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
 309                                 ea_value, buf_size, ACL_TYPE_DEFAULT,
 310                                 cifs_sb->local_nls,
 311                                 cifs_sb->mnt_cifs_flags &
 312                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 313 #else
 314                 cFYI(1, "Query POSIX default ACL not supported yet");
 315 #endif /* CONFIG_CIFS_POSIX */
 316         } else if (strncmp(ea_name, CIFS_XATTR_CIFS_ACL,
 317                                 strlen(CIFS_XATTR_CIFS_ACL)) == 0) {
 318 #ifdef CONFIG_CIFS_ACL
 319                         u32 acllen;
 320                         struct cifs_ntsd *pacl;
 321
 322                         pacl = get_cifs_acl(cifs_sb, direntry->d_inode,
 323                                                 full_path, &acllen);
 324                         if (IS_ERR(pacl)) {
 325                                 rc = PTR_ERR(pacl);
 326                                 cERROR(1, "%s: error %zd getting sec desc",
 327                                                 __func__, rc);
 328                         } else {
 329                                 if (ea_value) {
 330                                         if (acllen > buf_size)
 331                                                 acllen = -ERANGE;
 332                                         else
 333                                                 memcpy(ea_value, pacl, acllen);
 334                                 }
 335                                 rc = acllen;
 336                                 kfree(pacl);
 337                         }
 338 #else
 339                 cFYI(1, "Query CIFS ACL not supported yet");
 340 #endif /* CONFIG_CIFS_ACL */
 341         } else if (strncmp(ea_name,
 342                   CIFS_XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) == 0) {
 343                 cFYI(1, "Trusted xattr namespace not supported yet");
 344         } else if (strncmp(ea_name,
 345                   CIFS_XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) == 0) {
 346                 cFYI(1, "Security xattr namespace not supported yet");
 347         } else
 348                 cFYI(1,
 349                     "illegal xattr request %s (only user namespace supported)",
 350                      ea_name);
 351
 352         /* We could add an additional check for streams ie
 353             if proc/fs/cifs/streamstoxattr is set then
 354                 search server for EAs or streams to
 355                 returns as xattrs */
 356
 357         if (rc == -EINVAL)
 358                 rc = -EOPNOTSUPP;
 359
 360 get_ea_exit:
 361         kfree(full_path);
 362         FreeXid(xid);
 363         cifs_put_tlink(tlink);
 364 #endif
 365         return rc;
 366 }
 367
 368 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
 369 {
 370         ssize_t rc = -EOPNOTSUPP;
 371 #ifdef CONFIG_CIFS_XATTR
 372         int xid;
 373         struct cifs_sb_info *cifs_sb;
 374         struct tcon_link *tlink;
 375         struct cifsTconInfo *pTcon;
 376         struct super_block *sb;
 377         char *full_path;
 378
 379         if (direntry == NULL)
 380                 return -EIO;
 381         if (direntry->d_inode == NULL)
 382                 return -EIO;
 383         sb = direntry->d_inode->i_sb;
 384         if (sb == NULL)
 385                 return -EIO;
 386
 387         cifs_sb = CIFS_SB(sb);
 388         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 389                 return -EOPNOTSUPP;
 390
 391         tlink = cifs_sb_tlink(cifs_sb);
 392         if (IS_ERR(tlink))
 393                 return PTR_ERR(tlink);
 394         pTcon = tlink_tcon(tlink);
 395
 396         xid = GetXid();
 397
 398         full_path = build_path_from_dentry(direntry);
 399         if (full_path == NULL) {
 400                 rc = -ENOMEM;
 401                 goto list_ea_exit;
 402         }
 403         /* return dos attributes as pseudo xattr */
 404         /* return alt name if available as pseudo attr */
 405
 406         /* if proc/fs/cifs/streamstoxattr is set then
 407                 search server for EAs or streams to
 408                 returns as xattrs */
 409         rc = CIFSSMBQAllEAs(xid, pTcon, full_path, NULL, data,
 410                                 buf_size, cifs_sb->local_nls,
 411                                 cifs_sb->mnt_cifs_flags &
 412                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 413
 414 list_ea_exit:
 415         kfree(full_path);
 416         FreeXid(xid);
 417         cifs_put_tlink(tlink);
 418 #endif
 419         return rc;
 420 }