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_CIFS_NTSD_FULL "system.cifs_ntsd_full" /* owner/DACL/SACL */
  38 #define CIFS_XATTR_ATTRIB "cifs.dosattrib"  /* full name: user.cifs.dosattrib */
  39 #define CIFS_XATTR_CREATETIME "cifs.creationtime"  /* user.cifs.creationtime */
  40 /*
  41  * Although these three are just aliases for the above, need to move away from
  42  * confusing users and using the 20+ year old term 'cifs' when it is no longer
  43  * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
  44  */
  45 #define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
  46 #define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
  47 #define SMB3_XATTR_CIFS_NTSD_FULL "system.smb3_ntsd_full" /* owner/DACL/SACL */
  48 #define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
  49 #define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
  50 /* BB need to add server (Samba e.g) support for security and trusted prefix */
  51
  52 enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
  53         XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };
  54
  55 static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
  56                            struct inode *inode, char *full_path,
  57                            const void *value, size_t size)
  58 {
  59         ssize_t rc = -EOPNOTSUPP;
  60         __u32 *pattrib = (__u32 *)value;
  61         __u32 attrib;
  62         FILE_BASIC_INFO info_buf;
  63
  64         if ((value == NULL) || (size != sizeof(__u32)))
  65                 return -ERANGE;
  66
  67         memset(&info_buf, 0, sizeof(info_buf));
  68         attrib = *pattrib;
  69         info_buf.Attributes = cpu_to_le32(attrib);
  70         if (pTcon->ses->server->ops->set_file_info)
  71                 rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
  72                                 &info_buf, xid);
  73         if (rc == 0)
  74                 CIFS_I(inode)->cifsAttrs = attrib;
  75
  76         return rc;
  77 }
  78
  79 static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
  80                                   struct inode *inode, char *full_path,
  81                                   const void *value, size_t size)
  82 {
  83         ssize_t rc = -EOPNOTSUPP;
  84         __u64 *pcreation_time = (__u64 *)value;
  85         __u64 creation_time;
  86         FILE_BASIC_INFO info_buf;
  87
  88         if ((value == NULL) || (size != sizeof(__u64)))
  89                 return -ERANGE;
  90
  91         memset(&info_buf, 0, sizeof(info_buf));
  92         creation_time = *pcreation_time;
  93         info_buf.CreationTime = cpu_to_le64(creation_time);
  94         if (pTcon->ses->server->ops->set_file_info)
  95                 rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
  96                                 &info_buf, xid);
  97         if (rc == 0)
  98                 CIFS_I(inode)->createtime = creation_time;
  99
 100         return rc;
 101 }
 102
 103 static int cifs_xattr_set(const struct xattr_handler *handler,
 104                           struct dentry *dentry, struct inode *inode,
 105                           const char *name, const void *value,
 106                           size_t size, int flags)
 107 {
 108         int rc = -EOPNOTSUPP;
 109         unsigned int xid;
 110         struct super_block *sb = dentry->d_sb;
 111         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 112         struct tcon_link *tlink;
 113         struct cifs_tcon *pTcon;
 114         char *full_path;
 115
 116         tlink = cifs_sb_tlink(cifs_sb);
 117         if (IS_ERR(tlink))
 118                 return PTR_ERR(tlink);
 119         pTcon = tlink_tcon(tlink);
 120
 121         xid = get_xid();
 122
 123         full_path = build_path_from_dentry(dentry);
 124         if (full_path == NULL) {
 125                 rc = -ENOMEM;
 126                 goto out;
 127         }
 128         /* return dos attributes as pseudo xattr */
 129         /* return alt name if available as pseudo attr */
 130
 131         /* if proc/fs/cifs/streamstoxattr is set then
 132                 search server for EAs or streams to
 133                 returns as xattrs */
 134         if (size > MAX_EA_VALUE_SIZE) {
 135                 cifs_dbg(FYI, "size of EA value too large\n");
 136                 rc = -EOPNOTSUPP;
 137                 goto out;
 138         }
 139
 140         switch (handler->flags) {
 141         case XATTR_USER:
 142                 cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
 143                 if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
 144                     (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
 145                         rc = cifs_attrib_set(xid, pTcon, inode, full_path,
 146                                         value, size);
 147                         if (rc == 0) /* force revalidate of the inode */
 148                                 CIFS_I(inode)->time = 0;
 149                         break;
 150                 } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
 151                            (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
 152                         rc = cifs_creation_time_set(xid, pTcon, inode,
 153                                         full_path, value, size);
 154                         if (rc == 0) /* force revalidate of the inode */
 155                                 CIFS_I(inode)->time = 0;
 156                         break;
 157                 }
 158
 159                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 160                         goto out;
 161
 162                 if (pTcon->ses->server->ops->set_EA)
 163                         rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
 164                                 full_path, name, value, (__u16)size,
 165                                 cifs_sb->local_nls, cifs_sb);
 166                 break;
 167
 168         case XATTR_CIFS_ACL:
 169         case XATTR_CIFS_NTSD:
 170         case XATTR_CIFS_NTSD_FULL: {
 171                 struct cifs_ntsd *pacl;
 172
 173                 if (!value)
 174                         goto out;
 175                 pacl = kmalloc(size, GFP_KERNEL);
 176                 if (!pacl) {
 177                         rc = -ENOMEM;
 178                 } else {
 179                         memcpy(pacl, value, size);
 180                         if (pTcon->ses->server->ops->set_acl) {
 181                                 int aclflags = 0;
 182                                 rc = 0;
 183
 184                                 switch (handler->flags) {
 185                                 case XATTR_CIFS_NTSD_FULL:
 186                                         aclflags = (CIFS_ACL_OWNER |
 187                                                     CIFS_ACL_DACL |
 188                                                     CIFS_ACL_SACL);
 189                                         break;
 190                                 case XATTR_CIFS_NTSD:
 191                                         aclflags = (CIFS_ACL_OWNER |
 192                                                     CIFS_ACL_DACL);
 193                                         break;
 194                                 case XATTR_CIFS_ACL:
 195                                 default:
 196                                         aclflags = CIFS_ACL_DACL;
 197                                 }
 198
 199                                 rc = pTcon->ses->server->ops->set_acl(pacl,
 200                                         size, inode, full_path, aclflags);
 201                         } else {
 202                                 rc = -EOPNOTSUPP;
 203                         }
 204                         if (rc == 0) /* force revalidate of the inode */
 205                                 CIFS_I(inode)->time = 0;
 206                         kfree(pacl);
 207                 }
 208                 break;
 209         }
 210
 211         case XATTR_ACL_ACCESS:
 212 #ifdef CONFIG_CIFS_POSIX
 213                 if (!value)
 214                         goto out;
 215                 if (sb->s_flags & SB_POSIXACL)
 216                         rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 217                                 value, (const int)size,
 218                                 ACL_TYPE_ACCESS, cifs_sb->local_nls,
 219                                 cifs_remap(cifs_sb));
 220 #endif  /* CONFIG_CIFS_POSIX */
 221                 break;
 222
 223         case XATTR_ACL_DEFAULT:
 224 #ifdef CONFIG_CIFS_POSIX
 225                 if (!value)
 226                         goto out;
 227                 if (sb->s_flags & SB_POSIXACL)
 228                         rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 229                                 value, (const int)size,
 230                                 ACL_TYPE_DEFAULT, cifs_sb->local_nls,
 231                                 cifs_remap(cifs_sb));
 232 #endif  /* CONFIG_CIFS_POSIX */
 233                 break;
 234         }
 235
 236 out:
 237         kfree(full_path);
 238         free_xid(xid);
 239         cifs_put_tlink(tlink);
 240         return rc;
 241 }
 242
 243 static int cifs_attrib_get(struct dentry *dentry,
 244                            struct inode *inode, void *value,
 245                            size_t size)
 246 {
 247         ssize_t rc;
 248         __u32 *pattribute;
 249
 250         rc = cifs_revalidate_dentry_attr(dentry);
 251
 252         if (rc)
 253                 return rc;
 254
 255         if ((value == NULL) || (size == 0))
 256                 return sizeof(__u32);
 257         else if (size < sizeof(__u32))
 258                 return -ERANGE;
 259
 260         /* return dos attributes as pseudo xattr */
 261         pattribute = (__u32 *)value;
 262         *pattribute = CIFS_I(inode)->cifsAttrs;
 263
 264         return sizeof(__u32);
 265 }
 266
 267 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
 268                                   void *value, size_t size)
 269 {
 270         ssize_t rc;
 271         __u64 *pcreatetime;
 272
 273         rc = cifs_revalidate_dentry_attr(dentry);
 274         if (rc)
 275                 return rc;
 276
 277         if ((value == NULL) || (size == 0))
 278                 return sizeof(__u64);
 279         else if (size < sizeof(__u64))
 280                 return -ERANGE;
 281
 282         /* return dos attributes as pseudo xattr */
 283         pcreatetime = (__u64 *)value;
 284         *pcreatetime = CIFS_I(inode)->createtime;
 285         return sizeof(__u64);
 286 }
 287
 288
 289 static int cifs_xattr_get(const struct xattr_handler *handler,
 290                           struct dentry *dentry, struct inode *inode,
 291                           const char *name, void *value, size_t size)
 292 {
 293         ssize_t rc = -EOPNOTSUPP;
 294         unsigned int xid;
 295         struct super_block *sb = dentry->d_sb;
 296         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 297         struct tcon_link *tlink;
 298         struct cifs_tcon *pTcon;
 299         char *full_path;
 300
 301         tlink = cifs_sb_tlink(cifs_sb);
 302         if (IS_ERR(tlink))
 303                 return PTR_ERR(tlink);
 304         pTcon = tlink_tcon(tlink);
 305
 306         xid = get_xid();
 307
 308         full_path = build_path_from_dentry(dentry);
 309         if (full_path == NULL) {
 310                 rc = -ENOMEM;
 311                 goto out;
 312         }
 313
 314         /* return alt name if available as pseudo attr */
 315         switch (handler->flags) {
 316         case XATTR_USER:
 317                 cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
 318                 if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
 319                     (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
 320                         rc = cifs_attrib_get(dentry, inode, value, size);
 321                         break;
 322                 } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
 323                     (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
 324                         rc = cifs_creation_time_get(dentry, inode, value, size);
 325                         break;
 326                 }
 327
 328                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 329                         goto out;
 330
 331                 if (pTcon->ses->server->ops->query_all_EAs)
 332                         rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 333                                 full_path, name, value, size, cifs_sb);
 334                 break;
 335
 336         case XATTR_CIFS_ACL:
 337         case XATTR_CIFS_NTSD:
 338         case XATTR_CIFS_NTSD_FULL: {
 339                 /*
 340                  * fetch owner, DACL, and SACL if asked for full descriptor,
 341                  * fetch owner and DACL otherwise
 342                  */
 343                 u32 acllen, extra_info;
 344                 struct cifs_ntsd *pacl;
 345
 346                 if (pTcon->ses->server->ops->get_acl == NULL)
 347                         goto out; /* rc already EOPNOTSUPP */
 348
 349                 if (handler->flags == XATTR_CIFS_NTSD_FULL) {
 350                         extra_info = SACL_SECINFO;
 351                 } else {
 352                         extra_info = 0;
 353                 }
 354                 pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
 355                                 inode, full_path, &acllen, extra_info);
 356                 if (IS_ERR(pacl)) {
 357                         rc = PTR_ERR(pacl);
 358                         cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
 359                                  __func__, rc);
 360                 } else {
 361                         if (value) {
 362                                 if (acllen > size)
 363                                         acllen = -ERANGE;
 364                                 else
 365                                         memcpy(value, pacl, acllen);
 366                         }
 367                         rc = acllen;
 368                         kfree(pacl);
 369                 }
 370                 break;
 371         }
 372
 373         case XATTR_ACL_ACCESS:
 374 #ifdef CONFIG_CIFS_POSIX
 375                 if (sb->s_flags & SB_POSIXACL)
 376                         rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
 377                                 value, size, ACL_TYPE_ACCESS,
 378                                 cifs_sb->local_nls,
 379                                 cifs_remap(cifs_sb));
 380 #endif  /* CONFIG_CIFS_POSIX */
 381                 break;
 382
 383         case XATTR_ACL_DEFAULT:
 384 #ifdef CONFIG_CIFS_POSIX
 385                 if (sb->s_flags & SB_POSIXACL)
 386                         rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
 387                                 value, size, ACL_TYPE_DEFAULT,
 388                                 cifs_sb->local_nls,
 389                                 cifs_remap(cifs_sb));
 390 #endif  /* CONFIG_CIFS_POSIX */
 391                 break;
 392         }
 393
 394         /* We could add an additional check for streams ie
 395             if proc/fs/cifs/streamstoxattr is set then
 396                 search server for EAs or streams to
 397                 returns as xattrs */
 398
 399         if (rc == -EINVAL)
 400                 rc = -EOPNOTSUPP;
 401
 402 out:
 403         kfree(full_path);
 404         free_xid(xid);
 405         cifs_put_tlink(tlink);
 406         return rc;
 407 }
 408
 409 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
 410 {
 411         ssize_t rc = -EOPNOTSUPP;
 412         unsigned int xid;
 413         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 414         struct tcon_link *tlink;
 415         struct cifs_tcon *pTcon;
 416         char *full_path;
 417
 418         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 419                 return -EOPNOTSUPP;
 420
 421         tlink = cifs_sb_tlink(cifs_sb);
 422         if (IS_ERR(tlink))
 423                 return PTR_ERR(tlink);
 424         pTcon = tlink_tcon(tlink);
 425
 426         xid = get_xid();
 427
 428         full_path = build_path_from_dentry(direntry);
 429         if (full_path == NULL) {
 430                 rc = -ENOMEM;
 431                 goto list_ea_exit;
 432         }
 433         /* return dos attributes as pseudo xattr */
 434         /* return alt name if available as pseudo attr */
 435
 436         /* if proc/fs/cifs/streamstoxattr is set then
 437                 search server for EAs or streams to
 438                 returns as xattrs */
 439
 440         if (pTcon->ses->server->ops->query_all_EAs)
 441                 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 442                                 full_path, NULL, data, buf_size, cifs_sb);
 443 list_ea_exit:
 444         kfree(full_path);
 445         free_xid(xid);
 446         cifs_put_tlink(tlink);
 447         return rc;
 448 }
 449
 450 static const struct xattr_handler cifs_user_xattr_handler = {
 451         .prefix = XATTR_USER_PREFIX,
 452         .flags = XATTR_USER,
 453         .get = cifs_xattr_get,
 454         .set = cifs_xattr_set,
 455 };
 456
 457 /* os2.* attributes are treated like user.* attributes */
 458 static const struct xattr_handler cifs_os2_xattr_handler = {
 459         .prefix = XATTR_OS2_PREFIX,
 460         .flags = XATTR_USER,
 461         .get = cifs_xattr_get,
 462         .set = cifs_xattr_set,
 463 };
 464
 465 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
 466         .name = CIFS_XATTR_CIFS_ACL,
 467         .flags = XATTR_CIFS_ACL,
 468         .get = cifs_xattr_get,
 469         .set = cifs_xattr_set,
 470 };
 471
 472 /*
 473  * Although this is just an alias for the above, need to move away from
 474  * confusing users and using the 20 year old term 'cifs' when it is no
 475  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 476  * SMB3 and later are highly secure.
 477  */
 478 static const struct xattr_handler smb3_acl_xattr_handler = {
 479         .name = SMB3_XATTR_CIFS_ACL,
 480         .flags = XATTR_CIFS_ACL,
 481         .get = cifs_xattr_get,
 482         .set = cifs_xattr_set,
 483 };
 484
 485 static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
 486         .name = CIFS_XATTR_CIFS_NTSD,
 487         .flags = XATTR_CIFS_NTSD,
 488         .get = cifs_xattr_get,
 489         .set = cifs_xattr_set,
 490 };
 491
 492 /*
 493  * Although this is just an alias for the above, need to move away from
 494  * confusing users and using the 20 year old term 'cifs' when it is no
 495  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 496  * SMB3 and later are highly secure.
 497  */
 498 static const struct xattr_handler smb3_ntsd_xattr_handler = {
 499         .name = SMB3_XATTR_CIFS_NTSD,
 500         .flags = XATTR_CIFS_NTSD,
 501         .get = cifs_xattr_get,
 502         .set = cifs_xattr_set,
 503 };
 504
 505 static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
 506         .name = CIFS_XATTR_CIFS_NTSD_FULL,
 507         .flags = XATTR_CIFS_NTSD_FULL,
 508         .get = cifs_xattr_get,
 509         .set = cifs_xattr_set,
 510 };
 511
 512 /*
 513  * Although this is just an alias for the above, need to move away from
 514  * confusing users and using the 20 year old term 'cifs' when it is no
 515  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 516  * SMB3 and later are highly secure.
 517  */
 518 static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
 519         .name = SMB3_XATTR_CIFS_NTSD_FULL,
 520         .flags = XATTR_CIFS_NTSD_FULL,
 521         .get = cifs_xattr_get,
 522         .set = cifs_xattr_set,
 523 };
 524
 525
 526 static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
 527         .name = XATTR_NAME_POSIX_ACL_ACCESS,
 528         .flags = XATTR_ACL_ACCESS,
 529         .get = cifs_xattr_get,
 530         .set = cifs_xattr_set,
 531 };
 532
 533 static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
 534         .name = XATTR_NAME_POSIX_ACL_DEFAULT,
 535         .flags = XATTR_ACL_DEFAULT,
 536         .get = cifs_xattr_get,
 537         .set = cifs_xattr_set,
 538 };
 539
 540 const struct xattr_handler *cifs_xattr_handlers[] = {
 541         &cifs_user_xattr_handler,
 542         &cifs_os2_xattr_handler,
 543         &cifs_cifs_acl_xattr_handler,
 544         &smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
 545         &cifs_cifs_ntsd_xattr_handler,
 546         &smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
 547         &cifs_cifs_ntsd_full_xattr_handler,
 548         &smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
 549         &cifs_posix_acl_access_xattr_handler,
 550         &cifs_posix_acl_default_xattr_handler,
 551         NULL
 552 };