fs/smb/client/xattr.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *
   4  *   Copyright (c) International Business Machines  Corp., 2003, 2007
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  */
   8
   9 #include <linux/fs.h>
  10 #include <linux/posix_acl_xattr.h>
  11 #include <linux/slab.h>
  12 #include <linux/xattr.h>
  13 #include "cifsfs.h"
  14 #include "cifspdu.h"
  15 #include "cifsglob.h"
  16 #include "cifsproto.h"
  17 #include "cifs_debug.h"
  18 #include "cifs_fs_sb.h"
  19 #include "cifs_unicode.h"
  20 #include "cifs_ioctl.h"
  21
  22 #define MAX_EA_VALUE_SIZE CIFSMaxBufSize
  23 #define CIFS_XATTR_CIFS_ACL "system.cifs_acl" /* DACL only */
  24 #define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
  25 #define CIFS_XATTR_CIFS_NTSD_FULL "system.cifs_ntsd_full" /* owner/DACL/SACL */
  26 #define CIFS_XATTR_ATTRIB "cifs.dosattrib"  /* full name: user.cifs.dosattrib */
  27 #define CIFS_XATTR_CREATETIME "cifs.creationtime"  /* user.cifs.creationtime */
  28 /*
  29  * Although these three are just aliases for the above, need to move away from
  30  * confusing users and using the 20+ year old term 'cifs' when it is no longer
  31  * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
  32  */
  33 #define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
  34 #define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
  35 #define SMB3_XATTR_CIFS_NTSD_FULL "system.smb3_ntsd_full" /* owner/DACL/SACL */
  36 #define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
  37 #define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
  38 /* BB need to add server (Samba e.g) support for security and trusted prefix */
  39
  40 enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
  41         XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };
  42
  43 static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
  44                            struct inode *inode, const char *full_path,
  45                            const void *value, size_t size)
  46 {
  47         ssize_t rc = -EOPNOTSUPP;
  48         __u32 *pattrib = (__u32 *)value;
  49         __u32 attrib;
  50         FILE_BASIC_INFO info_buf;
  51
  52         if ((value == NULL) || (size != sizeof(__u32)))
  53                 return -ERANGE;
  54
  55         memset(&info_buf, 0, sizeof(info_buf));
  56         attrib = *pattrib;
  57         info_buf.Attributes = cpu_to_le32(attrib);
  58         if (pTcon->ses->server->ops->set_file_info)
  59                 rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
  60                                 &info_buf, xid);
  61         if (rc == 0)
  62                 CIFS_I(inode)->cifsAttrs = attrib;
  63
  64         return rc;
  65 }
  66
  67 static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
  68                                   struct inode *inode, const char *full_path,
  69                                   const void *value, size_t size)
  70 {
  71         ssize_t rc = -EOPNOTSUPP;
  72         __u64 *pcreation_time = (__u64 *)value;
  73         __u64 creation_time;
  74         FILE_BASIC_INFO info_buf;
  75
  76         if ((value == NULL) || (size != sizeof(__u64)))
  77                 return -ERANGE;
  78
  79         memset(&info_buf, 0, sizeof(info_buf));
  80         creation_time = *pcreation_time;
  81         info_buf.CreationTime = cpu_to_le64(creation_time);
  82         if (pTcon->ses->server->ops->set_file_info)
  83                 rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
  84                                 &info_buf, xid);
  85         if (rc == 0)
  86                 CIFS_I(inode)->createtime = creation_time;
  87
  88         return rc;
  89 }
  90
  91 static int cifs_xattr_set(const struct xattr_handler *handler,
  92                           struct mnt_idmap *idmap,
  93                           struct dentry *dentry, struct inode *inode,
  94                           const char *name, const void *value,
  95                           size_t size, int flags)
  96 {
  97         int rc = -EOPNOTSUPP;
  98         unsigned int xid;
  99         struct super_block *sb = dentry->d_sb;
 100         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 101         struct tcon_link *tlink;
 102         struct cifs_tcon *pTcon;
 103         const char *full_path;
 104         void *page;
 105
 106         tlink = cifs_sb_tlink(cifs_sb);
 107         if (IS_ERR(tlink))
 108                 return PTR_ERR(tlink);
 109         pTcon = tlink_tcon(tlink);
 110
 111         xid = get_xid();
 112         page = alloc_dentry_path();
 113
 114         full_path = build_path_from_dentry(dentry, page);
 115         if (IS_ERR(full_path)) {
 116                 rc = PTR_ERR(full_path);
 117                 goto out;
 118         }
 119         /* return dos attributes as pseudo xattr */
 120         /* return alt name if available as pseudo attr */
 121
 122         /* if proc/fs/cifs/streamstoxattr is set then
 123                 search server for EAs or streams to
 124                 returns as xattrs */
 125         if (size > MAX_EA_VALUE_SIZE) {
 126                 cifs_dbg(FYI, "size of EA value too large\n");
 127                 rc = -EOPNOTSUPP;
 128                 goto out;
 129         }
 130
 131         switch (handler->flags) {
 132         case XATTR_USER:
 133                 cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
 134                 if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
 135                     (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
 136                         rc = cifs_attrib_set(xid, pTcon, inode, full_path,
 137                                         value, size);
 138                         if (rc == 0) /* force revalidate of the inode */
 139                                 CIFS_I(inode)->time = 0;
 140                         break;
 141                 } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
 142                            (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
 143                         rc = cifs_creation_time_set(xid, pTcon, inode,
 144                                         full_path, value, size);
 145                         if (rc == 0) /* force revalidate of the inode */
 146                                 CIFS_I(inode)->time = 0;
 147                         break;
 148                 }
 149
 150                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 151                         goto out;
 152
 153                 if (pTcon->ses->server->ops->set_EA) {
 154                         rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
 155                                 full_path, name, value, (__u16)size,
 156                                 cifs_sb->local_nls, cifs_sb);
 157                         if (rc == 0)
 158                                 inode_set_ctime_current(inode);
 159                 }
 160                 break;
 161
 162         case XATTR_CIFS_ACL:
 163         case XATTR_CIFS_NTSD:
 164         case XATTR_CIFS_NTSD_FULL: {
 165                 struct smb_ntsd *pacl;
 166
 167                 if (!value)
 168                         goto out;
 169                 pacl = kmalloc(size, GFP_KERNEL);
 170                 if (!pacl) {
 171                         rc = -ENOMEM;
 172                 } else {
 173                         memcpy(pacl, value, size);
 174                         if (pTcon->ses->server->ops->set_acl) {
 175                                 int aclflags = 0;
 176                                 rc = 0;
 177
 178                                 switch (handler->flags) {
 179                                 case XATTR_CIFS_NTSD_FULL:
 180                                         aclflags = (CIFS_ACL_OWNER |
 181                                                     CIFS_ACL_GROUP |
 182                                                     CIFS_ACL_DACL |
 183                                                     CIFS_ACL_SACL);
 184                                         break;
 185                                 case XATTR_CIFS_NTSD:
 186                                         aclflags = (CIFS_ACL_OWNER |
 187                                                     CIFS_ACL_GROUP |
 188                                                     CIFS_ACL_DACL);
 189                                         break;
 190                                 case XATTR_CIFS_ACL:
 191                                 default:
 192                                         aclflags = CIFS_ACL_DACL;
 193                                 }
 194
 195                                 rc = pTcon->ses->server->ops->set_acl(pacl,
 196                                         size, inode, full_path, aclflags);
 197                         } else {
 198                                 rc = -EOPNOTSUPP;
 199                         }
 200                         if (rc == 0) /* force revalidate of the inode */
 201                                 CIFS_I(inode)->time = 0;
 202                         kfree(pacl);
 203                 }
 204                 break;
 205         }
 206         }
 207
 208 out:
 209         free_dentry_path(page);
 210         free_xid(xid);
 211         cifs_put_tlink(tlink);
 212         return rc;
 213 }
 214
 215 static int cifs_attrib_get(struct dentry *dentry,
 216                            struct inode *inode, void *value,
 217                            size_t size)
 218 {
 219         ssize_t rc;
 220         __u32 *pattribute;
 221
 222         rc = cifs_revalidate_dentry_attr(dentry);
 223
 224         if (rc)
 225                 return rc;
 226
 227         if ((value == NULL) || (size == 0))
 228                 return sizeof(__u32);
 229         else if (size < sizeof(__u32))
 230                 return -ERANGE;
 231
 232         /* return dos attributes as pseudo xattr */
 233         pattribute = (__u32 *)value;
 234         *pattribute = CIFS_I(inode)->cifsAttrs;
 235
 236         return sizeof(__u32);
 237 }
 238
 239 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
 240                                   void *value, size_t size)
 241 {
 242         ssize_t rc;
 243         __u64 *pcreatetime;
 244
 245         rc = cifs_revalidate_dentry_attr(dentry);
 246         if (rc)
 247                 return rc;
 248
 249         if ((value == NULL) || (size == 0))
 250                 return sizeof(__u64);
 251         else if (size < sizeof(__u64))
 252                 return -ERANGE;
 253
 254         /* return dos attributes as pseudo xattr */
 255         pcreatetime = (__u64 *)value;
 256         *pcreatetime = CIFS_I(inode)->createtime;
 257         return sizeof(__u64);
 258 }
 259
 260
 261 static int cifs_xattr_get(const struct xattr_handler *handler,
 262                           struct dentry *dentry, struct inode *inode,
 263                           const char *name, void *value, size_t size)
 264 {
 265         ssize_t rc = -EOPNOTSUPP;
 266         unsigned int xid;
 267         struct super_block *sb = dentry->d_sb;
 268         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 269         struct tcon_link *tlink;
 270         struct cifs_tcon *pTcon;
 271         const char *full_path;
 272         void *page;
 273
 274         tlink = cifs_sb_tlink(cifs_sb);
 275         if (IS_ERR(tlink))
 276                 return PTR_ERR(tlink);
 277         pTcon = tlink_tcon(tlink);
 278
 279         xid = get_xid();
 280         page = alloc_dentry_path();
 281
 282         full_path = build_path_from_dentry(dentry, page);
 283         if (IS_ERR(full_path)) {
 284                 rc = PTR_ERR(full_path);
 285                 goto out;
 286         }
 287
 288         /* return alt name if available as pseudo attr */
 289         switch (handler->flags) {
 290         case XATTR_USER:
 291                 cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
 292                 if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
 293                     (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
 294                         rc = cifs_attrib_get(dentry, inode, value, size);
 295                         break;
 296                 } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
 297                     (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
 298                         rc = cifs_creation_time_get(dentry, inode, value, size);
 299                         break;
 300                 }
 301
 302                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 303                         goto out;
 304
 305                 if (pTcon->ses->server->ops->query_all_EAs)
 306                         rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 307                                 full_path, name, value, size, cifs_sb);
 308                 break;
 309
 310         case XATTR_CIFS_ACL:
 311         case XATTR_CIFS_NTSD:
 312         case XATTR_CIFS_NTSD_FULL: {
 313                 /*
 314                  * fetch owner, DACL, and SACL if asked for full descriptor,
 315                  * fetch owner and DACL otherwise
 316                  */
 317                 u32 acllen, extra_info;
 318                 struct smb_ntsd *pacl;
 319
 320                 if (pTcon->ses->server->ops->get_acl == NULL)
 321                         goto out; /* rc already EOPNOTSUPP */
 322
 323                 if (handler->flags == XATTR_CIFS_NTSD_FULL) {
 324                         extra_info = SACL_SECINFO;
 325                 } else {
 326                         extra_info = 0;
 327                 }
 328                 pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
 329                                 inode, full_path, &acllen, extra_info);
 330                 if (IS_ERR(pacl)) {
 331                         rc = PTR_ERR(pacl);
 332                         cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
 333                                  __func__, rc);
 334                 } else {
 335                         if (value) {
 336                                 if (acllen > size)
 337                                         acllen = -ERANGE;
 338                                 else
 339                                         memcpy(value, pacl, acllen);
 340                         }
 341                         rc = acllen;
 342                         kfree(pacl);
 343                 }
 344                 break;
 345         }
 346         }
 347
 348         /* We could add an additional check for streams ie
 349             if proc/fs/cifs/streamstoxattr is set then
 350                 search server for EAs or streams to
 351                 returns as xattrs */
 352
 353         if (rc == -EINVAL)
 354                 rc = -EOPNOTSUPP;
 355
 356 out:
 357         free_dentry_path(page);
 358         free_xid(xid);
 359         cifs_put_tlink(tlink);
 360         return rc;
 361 }
 362
 363 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
 364 {
 365         ssize_t rc = -EOPNOTSUPP;
 366         unsigned int xid;
 367         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 368         struct tcon_link *tlink;
 369         struct cifs_tcon *pTcon;
 370         const char *full_path;
 371         void *page;
 372
 373         if (unlikely(cifs_forced_shutdown(cifs_sb)))
 374                 return -EIO;
 375
 376         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 377                 return -EOPNOTSUPP;
 378
 379         tlink = cifs_sb_tlink(cifs_sb);
 380         if (IS_ERR(tlink))
 381                 return PTR_ERR(tlink);
 382         pTcon = tlink_tcon(tlink);
 383
 384         xid = get_xid();
 385         page = alloc_dentry_path();
 386
 387         full_path = build_path_from_dentry(direntry, page);
 388         if (IS_ERR(full_path)) {
 389                 rc = PTR_ERR(full_path);
 390                 goto list_ea_exit;
 391         }
 392         /* return dos attributes as pseudo xattr */
 393         /* return alt name if available as pseudo attr */
 394
 395         /* if proc/fs/cifs/streamstoxattr is set then
 396                 search server for EAs or streams to
 397                 returns as xattrs */
 398
 399         if (pTcon->ses->server->ops->query_all_EAs)
 400                 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 401                                 full_path, NULL, data, buf_size, cifs_sb);
 402 list_ea_exit:
 403         free_dentry_path(page);
 404         free_xid(xid);
 405         cifs_put_tlink(tlink);
 406         return rc;
 407 }
 408
 409 static const struct xattr_handler cifs_user_xattr_handler = {
 410         .prefix = XATTR_USER_PREFIX,
 411         .flags = XATTR_USER,
 412         .get = cifs_xattr_get,
 413         .set = cifs_xattr_set,
 414 };
 415
 416 /* os2.* attributes are treated like user.* attributes */
 417 static const struct xattr_handler cifs_os2_xattr_handler = {
 418         .prefix = XATTR_OS2_PREFIX,
 419         .flags = XATTR_USER,
 420         .get = cifs_xattr_get,
 421         .set = cifs_xattr_set,
 422 };
 423
 424 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
 425         .name = CIFS_XATTR_CIFS_ACL,
 426         .flags = XATTR_CIFS_ACL,
 427         .get = cifs_xattr_get,
 428         .set = cifs_xattr_set,
 429 };
 430
 431 /*
 432  * Although this is just an alias for the above, need to move away from
 433  * confusing users and using the 20 year old term 'cifs' when it is no
 434  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 435  * SMB3 and later are highly secure.
 436  */
 437 static const struct xattr_handler smb3_acl_xattr_handler = {
 438         .name = SMB3_XATTR_CIFS_ACL,
 439         .flags = XATTR_CIFS_ACL,
 440         .get = cifs_xattr_get,
 441         .set = cifs_xattr_set,
 442 };
 443
 444 static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
 445         .name = CIFS_XATTR_CIFS_NTSD,
 446         .flags = XATTR_CIFS_NTSD,
 447         .get = cifs_xattr_get,
 448         .set = cifs_xattr_set,
 449 };
 450
 451 /*
 452  * Although this is just an alias for the above, need to move away from
 453  * confusing users and using the 20 year old term 'cifs' when it is no
 454  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 455  * SMB3 and later are highly secure.
 456  */
 457 static const struct xattr_handler smb3_ntsd_xattr_handler = {
 458         .name = SMB3_XATTR_CIFS_NTSD,
 459         .flags = XATTR_CIFS_NTSD,
 460         .get = cifs_xattr_get,
 461         .set = cifs_xattr_set,
 462 };
 463
 464 static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
 465         .name = CIFS_XATTR_CIFS_NTSD_FULL,
 466         .flags = XATTR_CIFS_NTSD_FULL,
 467         .get = cifs_xattr_get,
 468         .set = cifs_xattr_set,
 469 };
 470
 471 /*
 472  * Although this is just an alias for the above, need to move away from
 473  * confusing users and using the 20 year old term 'cifs' when it is no
 474  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 475  * SMB3 and later are highly secure.
 476  */
 477 static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
 478         .name = SMB3_XATTR_CIFS_NTSD_FULL,
 479         .flags = XATTR_CIFS_NTSD_FULL,
 480         .get = cifs_xattr_get,
 481         .set = cifs_xattr_set,
 482 };
 483
 484 const struct xattr_handler * const cifs_xattr_handlers[] = {
 485         &cifs_user_xattr_handler,
 486         &cifs_os2_xattr_handler,
 487         &cifs_cifs_acl_xattr_handler,
 488         &smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
 489         &cifs_cifs_ntsd_xattr_handler,
 490         &smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
 491         &cifs_cifs_ntsd_full_xattr_handler,
 492         &smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
 493         NULL
 494 };