kernel/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 <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
  40 int 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         }
  92 remove_ea_exit:
  93         kfree(full_path);
  94         free_xid(xid);
  95         cifs_put_tlink(tlink);
  96 #endif
  97         return rc;
  98 }
  99
 100 int 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
 227 set_ea_exit:
 228         kfree(full_path);
 229         free_xid(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         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
 364 get_ea_exit:
 365         kfree(full_path);
 366         free_xid(xid);
 367         cifs_put_tlink(tlink);
 368 #endif
 369         return rc;
 370 }
 371
 372 ssize_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));
 418 list_ea_exit:
 419         kfree(full_path);
 420         free_xid(xid);
 421         cifs_put_tlink(tlink);
 422 #endif
 423         return rc;
 424 }