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 CIFSMaxBufSize
  35 #define CIFS_XATTR_CIFS_ACL "system.cifs_acl" /* DACL only */
  36 #define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
  37 #define CIFS_XATTR_ATTRIB "cifs.dosattrib"  /* full name: user.cifs.dosattrib */
  38 #define CIFS_XATTR_CREATETIME "cifs.creationtime"  /* user.cifs.creationtime */
  39 /*
  40  * Although these three are just aliases for the above, need to move away from
  41  * confusing users and using the 20+ year old term 'cifs' when it is no longer
  42  * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
  43  */
  44 #define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
  45 #define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
  46 #define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
  47 #define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
  48 /* BB need to add server (Samba e.g) support for security and trusted prefix */
  49
  50 enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
  51         XATTR_CIFS_NTSD };
  52
  53 static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
  54                            struct inode *inode, char *full_path,
  55                            const void *value, size_t size)
  56 {
  57         ssize_t rc = -EOPNOTSUPP;
  58         __u32 *pattrib = (__u32 *)value;
  59         __u32 attrib;
  60         FILE_BASIC_INFO info_buf;
  61
  62         if ((value == NULL) || (size != sizeof(__u32)))
  63                 return -ERANGE;
  64
  65         memset(&info_buf, 0, sizeof(info_buf));
  66         attrib = *pattrib;
  67         info_buf.Attributes = cpu_to_le32(attrib);
  68         if (pTcon->ses->server->ops->set_file_info)
  69                 rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
  70                                 &info_buf, xid);
  71         if (rc == 0)
  72                 CIFS_I(inode)->cifsAttrs = attrib;
  73
  74         return rc;
  75 }
  76
  77 static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
  78                                   struct inode *inode, char *full_path,
  79                                   const void *value, size_t size)
  80 {
  81         ssize_t rc = -EOPNOTSUPP;
  82         __u64 *pcreation_time = (__u64 *)value;
  83         __u64 creation_time;
  84         FILE_BASIC_INFO info_buf;
  85
  86         if ((value == NULL) || (size != sizeof(__u64)))
  87                 return -ERANGE;
  88
  89         memset(&info_buf, 0, sizeof(info_buf));
  90         creation_time = *pcreation_time;
  91         info_buf.CreationTime = cpu_to_le64(creation_time);
  92         if (pTcon->ses->server->ops->set_file_info)
  93                 rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
  94                                 &info_buf, xid);
  95         if (rc == 0)
  96                 CIFS_I(inode)->createtime = creation_time;
  97
  98         return rc;
  99 }
 100
 101 static int cifs_xattr_set(const struct xattr_handler *handler,
 102                           struct dentry *dentry, struct inode *inode,
 103                           const char *name, const void *value,
 104                           size_t size, int flags)
 105 {
 106         int rc = -EOPNOTSUPP;
 107         unsigned int xid;
 108         struct super_block *sb = dentry->d_sb;
 109         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 110         struct tcon_link *tlink;
 111         struct cifs_tcon *pTcon;
 112         char *full_path;
 113
 114         tlink = cifs_sb_tlink(cifs_sb);
 115         if (IS_ERR(tlink))
 116                 return PTR_ERR(tlink);
 117         pTcon = tlink_tcon(tlink);
 118
 119         xid = get_xid();
 120
 121         full_path = build_path_from_dentry(dentry);
 122         if (full_path == NULL) {
 123                 rc = -ENOMEM;
 124                 goto out;
 125         }
 126         /* return dos attributes as pseudo xattr */
 127         /* return alt name if available as pseudo attr */
 128
 129         /* if proc/fs/cifs/streamstoxattr is set then
 130                 search server for EAs or streams to
 131                 returns as xattrs */
 132         if (size > MAX_EA_VALUE_SIZE) {
 133                 cifs_dbg(FYI, "size of EA value too large\n");
 134                 rc = -EOPNOTSUPP;
 135                 goto out;
 136         }
 137
 138         switch (handler->flags) {
 139         case XATTR_USER:
 140                 cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
 141                 if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
 142                     (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
 143                         rc = cifs_attrib_set(xid, pTcon, inode, full_path,
 144                                         value, size);
 145                         if (rc == 0) /* force revalidate of the inode */
 146                                 CIFS_I(inode)->time = 0;
 147                         break;
 148                 } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
 149                            (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
 150                         rc = cifs_creation_time_set(xid, pTcon, inode,
 151                                         full_path, value, size);
 152                         if (rc == 0) /* force revalidate of the inode */
 153                                 CIFS_I(inode)->time = 0;
 154                         break;
 155                 }
 156
 157                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 158                         goto out;
 159
 160                 if (pTcon->ses->server->ops->set_EA)
 161                         rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
 162                                 full_path, name, value, (__u16)size,
 163                                 cifs_sb->local_nls, cifs_sb);
 164                 break;
 165
 166         case XATTR_CIFS_ACL:
 167         case XATTR_CIFS_NTSD: {
 168                 struct cifs_ntsd *pacl;
 169
 170                 if (!value)
 171                         goto out;
 172                 pacl = kmalloc(size, GFP_KERNEL);
 173                 if (!pacl) {
 174                         rc = -ENOMEM;
 175                 } else {
 176                         memcpy(pacl, value, size);
 177                         if (value &&
 178                             pTcon->ses->server->ops->set_acl) {
 179                                 rc = 0;
 180                                 if (handler->flags == XATTR_CIFS_NTSD) {
 181                                         /* set owner and DACL */
 182                                         rc = pTcon->ses->server->ops->set_acl(
 183                                                         pacl, size, inode,
 184                                                         full_path,
 185                                                         CIFS_ACL_OWNER);
 186                                 }
 187                                 if (rc == 0) {
 188                                         /* set DACL */
 189                                         rc = pTcon->ses->server->ops->set_acl(
 190                                                         pacl, size, inode,
 191                                                         full_path,
 192                                                         CIFS_ACL_DACL);
 193                                 }
 194                         } else {
 195                                 rc = -EOPNOTSUPP;
 196                         }
 197                         if (rc == 0) /* force revalidate of the inode */
 198                                 CIFS_I(inode)->time = 0;
 199                         kfree(pacl);
 200                 }
 201                 break;
 202         }
 203
 204         case XATTR_ACL_ACCESS:
 205 #ifdef CONFIG_CIFS_POSIX
 206                 if (!value)
 207                         goto out;
 208                 if (sb->s_flags & SB_POSIXACL)
 209                         rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 210                                 value, (const int)size,
 211                                 ACL_TYPE_ACCESS, cifs_sb->local_nls,
 212                                 cifs_remap(cifs_sb));
 213 #endif  /* CONFIG_CIFS_POSIX */
 214                 break;
 215
 216         case XATTR_ACL_DEFAULT:
 217 #ifdef CONFIG_CIFS_POSIX
 218                 if (!value)
 219                         goto out;
 220                 if (sb->s_flags & SB_POSIXACL)
 221                         rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 222                                 value, (const int)size,
 223                                 ACL_TYPE_DEFAULT, cifs_sb->local_nls,
 224                                 cifs_remap(cifs_sb));
 225 #endif  /* CONFIG_CIFS_POSIX */
 226                 break;
 227         }
 228
 229 out:
 230         kfree(full_path);
 231         free_xid(xid);
 232         cifs_put_tlink(tlink);
 233         return rc;
 234 }
 235
 236 static int cifs_attrib_get(struct dentry *dentry,
 237                            struct inode *inode, void *value,
 238                            size_t size)
 239 {
 240         ssize_t rc;
 241         __u32 *pattribute;
 242
 243         rc = cifs_revalidate_dentry_attr(dentry);
 244
 245         if (rc)
 246                 return rc;
 247
 248         if ((value == NULL) || (size == 0))
 249                 return sizeof(__u32);
 250         else if (size < sizeof(__u32))
 251                 return -ERANGE;
 252
 253         /* return dos attributes as pseudo xattr */
 254         pattribute = (__u32 *)value;
 255         *pattribute = CIFS_I(inode)->cifsAttrs;
 256
 257         return sizeof(__u32);
 258 }
 259
 260 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
 261                                   void *value, size_t size)
 262 {
 263         ssize_t rc;
 264         __u64 *pcreatetime;
 265
 266         rc = cifs_revalidate_dentry_attr(dentry);
 267         if (rc)
 268                 return rc;
 269
 270         if ((value == NULL) || (size == 0))
 271                 return sizeof(__u64);
 272         else if (size < sizeof(__u64))
 273                 return -ERANGE;
 274
 275         /* return dos attributes as pseudo xattr */
 276         pcreatetime = (__u64 *)value;
 277         *pcreatetime = CIFS_I(inode)->createtime;
 278         return sizeof(__u64);
 279 }
 280
 281
 282 static int cifs_xattr_get(const struct xattr_handler *handler,
 283                           struct dentry *dentry, struct inode *inode,
 284                           const char *name, void *value, size_t size)
 285 {
 286         ssize_t rc = -EOPNOTSUPP;
 287         unsigned int xid;
 288         struct super_block *sb = dentry->d_sb;
 289         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 290         struct tcon_link *tlink;
 291         struct cifs_tcon *pTcon;
 292         char *full_path;
 293
 294         tlink = cifs_sb_tlink(cifs_sb);
 295         if (IS_ERR(tlink))
 296                 return PTR_ERR(tlink);
 297         pTcon = tlink_tcon(tlink);
 298
 299         xid = get_xid();
 300
 301         full_path = build_path_from_dentry(dentry);
 302         if (full_path == NULL) {
 303                 rc = -ENOMEM;
 304                 goto out;
 305         }
 306
 307         /* return alt name if available as pseudo attr */
 308         switch (handler->flags) {
 309         case XATTR_USER:
 310                 cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
 311                 if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
 312                     (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
 313                         rc = cifs_attrib_get(dentry, inode, value, size);
 314                         break;
 315                 } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
 316                     (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
 317                         rc = cifs_creation_time_get(dentry, inode, value, size);
 318                         break;
 319                 }
 320
 321                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 322                         goto out;
 323
 324                 if (pTcon->ses->server->ops->query_all_EAs)
 325                         rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 326                                 full_path, name, value, size, cifs_sb);
 327                 break;
 328
 329         case XATTR_CIFS_ACL:
 330         case XATTR_CIFS_NTSD: {
 331                 /* the whole ntsd is fetched regardless */
 332                 u32 acllen;
 333                 struct cifs_ntsd *pacl;
 334
 335                 if (pTcon->ses->server->ops->get_acl == NULL)
 336                         goto out; /* rc already EOPNOTSUPP */
 337
 338                 pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
 339                                 inode, full_path, &acllen);
 340                 if (IS_ERR(pacl)) {
 341                         rc = PTR_ERR(pacl);
 342                         cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
 343                                  __func__, rc);
 344                 } else {
 345                         if (value) {
 346                                 if (acllen > size)
 347                                         acllen = -ERANGE;
 348                                 else
 349                                         memcpy(value, pacl, acllen);
 350                         }
 351                         rc = acllen;
 352                         kfree(pacl);
 353                 }
 354                 break;
 355         }
 356
 357         case XATTR_ACL_ACCESS:
 358 #ifdef CONFIG_CIFS_POSIX
 359                 if (sb->s_flags & SB_POSIXACL)
 360                         rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
 361                                 value, size, ACL_TYPE_ACCESS,
 362                                 cifs_sb->local_nls,
 363                                 cifs_remap(cifs_sb));
 364 #endif  /* CONFIG_CIFS_POSIX */
 365                 break;
 366
 367         case XATTR_ACL_DEFAULT:
 368 #ifdef CONFIG_CIFS_POSIX
 369                 if (sb->s_flags & SB_POSIXACL)
 370                         rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
 371                                 value, size, ACL_TYPE_DEFAULT,
 372                                 cifs_sb->local_nls,
 373                                 cifs_remap(cifs_sb));
 374 #endif  /* CONFIG_CIFS_POSIX */
 375                 break;
 376         }
 377
 378         /* We could add an additional check for streams ie
 379             if proc/fs/cifs/streamstoxattr is set then
 380                 search server for EAs or streams to
 381                 returns as xattrs */
 382
 383         if (rc == -EINVAL)
 384                 rc = -EOPNOTSUPP;
 385
 386 out:
 387         kfree(full_path);
 388         free_xid(xid);
 389         cifs_put_tlink(tlink);
 390         return rc;
 391 }
 392
 393 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
 394 {
 395         ssize_t rc = -EOPNOTSUPP;
 396         unsigned int xid;
 397         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 398         struct tcon_link *tlink;
 399         struct cifs_tcon *pTcon;
 400         char *full_path;
 401
 402         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 403                 return -EOPNOTSUPP;
 404
 405         tlink = cifs_sb_tlink(cifs_sb);
 406         if (IS_ERR(tlink))
 407                 return PTR_ERR(tlink);
 408         pTcon = tlink_tcon(tlink);
 409
 410         xid = get_xid();
 411
 412         full_path = build_path_from_dentry(direntry);
 413         if (full_path == NULL) {
 414                 rc = -ENOMEM;
 415                 goto list_ea_exit;
 416         }
 417         /* return dos attributes as pseudo xattr */
 418         /* return alt name if available as pseudo attr */
 419
 420         /* if proc/fs/cifs/streamstoxattr is set then
 421                 search server for EAs or streams to
 422                 returns as xattrs */
 423
 424         if (pTcon->ses->server->ops->query_all_EAs)
 425                 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 426                                 full_path, NULL, data, buf_size, cifs_sb);
 427 list_ea_exit:
 428         kfree(full_path);
 429         free_xid(xid);
 430         cifs_put_tlink(tlink);
 431         return rc;
 432 }
 433
 434 static const struct xattr_handler cifs_user_xattr_handler = {
 435         .prefix = XATTR_USER_PREFIX,
 436         .flags = XATTR_USER,
 437         .get = cifs_xattr_get,
 438         .set = cifs_xattr_set,
 439 };
 440
 441 /* os2.* attributes are treated like user.* attributes */
 442 static const struct xattr_handler cifs_os2_xattr_handler = {
 443         .prefix = XATTR_OS2_PREFIX,
 444         .flags = XATTR_USER,
 445         .get = cifs_xattr_get,
 446         .set = cifs_xattr_set,
 447 };
 448
 449 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
 450         .name = CIFS_XATTR_CIFS_ACL,
 451         .flags = XATTR_CIFS_ACL,
 452         .get = cifs_xattr_get,
 453         .set = cifs_xattr_set,
 454 };
 455
 456 /*
 457  * Although this is just an alias for the above, need to move away from
 458  * confusing users and using the 20 year old term 'cifs' when it is no
 459  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 460  * SMB3 and later are highly secure.
 461  */
 462 static const struct xattr_handler smb3_acl_xattr_handler = {
 463         .name = SMB3_XATTR_CIFS_ACL,
 464         .flags = XATTR_CIFS_ACL,
 465         .get = cifs_xattr_get,
 466         .set = cifs_xattr_set,
 467 };
 468
 469 static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
 470         .name = CIFS_XATTR_CIFS_NTSD,
 471         .flags = XATTR_CIFS_NTSD,
 472         .get = cifs_xattr_get,
 473         .set = cifs_xattr_set,
 474 };
 475
 476 /*
 477  * Although this is just an alias for the above, need to move away from
 478  * confusing users and using the 20 year old term 'cifs' when it is no
 479  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 480  * SMB3 and later are highly secure.
 481  */
 482 static const struct xattr_handler smb3_ntsd_xattr_handler = {
 483         .name = SMB3_XATTR_CIFS_NTSD,
 484         .flags = XATTR_CIFS_NTSD,
 485         .get = cifs_xattr_get,
 486         .set = cifs_xattr_set,
 487 };
 488
 489 static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
 490         .name = XATTR_NAME_POSIX_ACL_ACCESS,
 491         .flags = XATTR_ACL_ACCESS,
 492         .get = cifs_xattr_get,
 493         .set = cifs_xattr_set,
 494 };
 495
 496 static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
 497         .name = XATTR_NAME_POSIX_ACL_DEFAULT,
 498         .flags = XATTR_ACL_DEFAULT,
 499         .get = cifs_xattr_get,
 500         .set = cifs_xattr_set,
 501 };
 502
 503 const struct xattr_handler *cifs_xattr_handlers[] = {
 504         &cifs_user_xattr_handler,
 505         &cifs_os2_xattr_handler,
 506         &cifs_cifs_acl_xattr_handler,
 507         &smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
 508         &cifs_cifs_ntsd_xattr_handler,
 509         &smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
 510         &cifs_posix_acl_access_xattr_handler,
 511         &cifs_posix_acl_default_xattr_handler,
 512         NULL
 513 };