fs/cifs/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                 break;
 158
 159         case XATTR_CIFS_ACL:
 160         case XATTR_CIFS_NTSD:
 161         case XATTR_CIFS_NTSD_FULL: {
 162                 struct cifs_ntsd *pacl;
 163
 164                 if (!value)
 165                         goto out;
 166                 pacl = kmalloc(size, GFP_KERNEL);
 167                 if (!pacl) {
 168                         rc = -ENOMEM;
 169                 } else {
 170                         memcpy(pacl, value, size);
 171                         if (pTcon->ses->server->ops->set_acl) {
 172                                 int aclflags = 0;
 173                                 rc = 0;
 174
 175                                 switch (handler->flags) {
 176                                 case XATTR_CIFS_NTSD_FULL:
 177                                         aclflags = (CIFS_ACL_OWNER |
 178                                                     CIFS_ACL_GROUP |
 179                                                     CIFS_ACL_DACL |
 180                                                     CIFS_ACL_SACL);
 181                                         break;
 182                                 case XATTR_CIFS_NTSD:
 183                                         aclflags = (CIFS_ACL_OWNER |
 184                                                     CIFS_ACL_GROUP |
 185                                                     CIFS_ACL_DACL);
 186                                         break;
 187                                 case XATTR_CIFS_ACL:
 188                                 default:
 189                                         aclflags = CIFS_ACL_DACL;
 190                                 }
 191
 192                                 rc = pTcon->ses->server->ops->set_acl(pacl,
 193                                         size, inode, full_path, aclflags);
 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
 205 out:
 206         free_dentry_path(page);
 207         free_xid(xid);
 208         cifs_put_tlink(tlink);
 209         return rc;
 210 }
 211
 212 static int cifs_attrib_get(struct dentry *dentry,
 213                            struct inode *inode, void *value,
 214                            size_t size)
 215 {
 216         ssize_t rc;
 217         __u32 *pattribute;
 218
 219         rc = cifs_revalidate_dentry_attr(dentry);
 220
 221         if (rc)
 222                 return rc;
 223
 224         if ((value == NULL) || (size == 0))
 225                 return sizeof(__u32);
 226         else if (size < sizeof(__u32))
 227                 return -ERANGE;
 228
 229         /* return dos attributes as pseudo xattr */
 230         pattribute = (__u32 *)value;
 231         *pattribute = CIFS_I(inode)->cifsAttrs;
 232
 233         return sizeof(__u32);
 234 }
 235
 236 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
 237                                   void *value, size_t size)
 238 {
 239         ssize_t rc;
 240         __u64 *pcreatetime;
 241
 242         rc = cifs_revalidate_dentry_attr(dentry);
 243         if (rc)
 244                 return rc;
 245
 246         if ((value == NULL) || (size == 0))
 247                 return sizeof(__u64);
 248         else if (size < sizeof(__u64))
 249                 return -ERANGE;
 250
 251         /* return dos attributes as pseudo xattr */
 252         pcreatetime = (__u64 *)value;
 253         *pcreatetime = CIFS_I(inode)->createtime;
 254         return sizeof(__u64);
 255 }
 256
 257
 258 static int cifs_xattr_get(const struct xattr_handler *handler,
 259                           struct dentry *dentry, struct inode *inode,
 260                           const char *name, void *value, size_t size)
 261 {
 262         ssize_t rc = -EOPNOTSUPP;
 263         unsigned int xid;
 264         struct super_block *sb = dentry->d_sb;
 265         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 266         struct tcon_link *tlink;
 267         struct cifs_tcon *pTcon;
 268         const char *full_path;
 269         void *page;
 270
 271         tlink = cifs_sb_tlink(cifs_sb);
 272         if (IS_ERR(tlink))
 273                 return PTR_ERR(tlink);
 274         pTcon = tlink_tcon(tlink);
 275
 276         xid = get_xid();
 277         page = alloc_dentry_path();
 278
 279         full_path = build_path_from_dentry(dentry, page);
 280         if (IS_ERR(full_path)) {
 281                 rc = PTR_ERR(full_path);
 282                 goto out;
 283         }
 284
 285         /* return alt name if available as pseudo attr */
 286         switch (handler->flags) {
 287         case XATTR_USER:
 288                 cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
 289                 if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
 290                     (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
 291                         rc = cifs_attrib_get(dentry, inode, value, size);
 292                         break;
 293                 } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
 294                     (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
 295                         rc = cifs_creation_time_get(dentry, inode, value, size);
 296                         break;
 297                 }
 298
 299                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 300                         goto out;
 301
 302                 if (pTcon->ses->server->ops->query_all_EAs)
 303                         rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 304                                 full_path, name, value, size, cifs_sb);
 305                 break;
 306
 307         case XATTR_CIFS_ACL:
 308         case XATTR_CIFS_NTSD:
 309         case XATTR_CIFS_NTSD_FULL: {
 310                 /*
 311                  * fetch owner, DACL, and SACL if asked for full descriptor,
 312                  * fetch owner and DACL otherwise
 313                  */
 314                 u32 acllen, extra_info;
 315                 struct cifs_ntsd *pacl;
 316
 317                 if (pTcon->ses->server->ops->get_acl == NULL)
 318                         goto out; /* rc already EOPNOTSUPP */
 319
 320                 if (handler->flags == XATTR_CIFS_NTSD_FULL) {
 321                         extra_info = SACL_SECINFO;
 322                 } else {
 323                         extra_info = 0;
 324                 }
 325                 pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
 326                                 inode, full_path, &acllen, extra_info);
 327                 if (IS_ERR(pacl)) {
 328                         rc = PTR_ERR(pacl);
 329                         cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
 330                                  __func__, rc);
 331                 } else {
 332                         if (value) {
 333                                 if (acllen > size)
 334                                         acllen = -ERANGE;
 335                                 else
 336                                         memcpy(value, pacl, acllen);
 337                         }
 338                         rc = acllen;
 339                         kfree(pacl);
 340                 }
 341                 break;
 342         }
 343         }
 344
 345         /* We could add an additional check for streams ie
 346             if proc/fs/cifs/streamstoxattr is set then
 347                 search server for EAs or streams to
 348                 returns as xattrs */
 349
 350         if (rc == -EINVAL)
 351                 rc = -EOPNOTSUPP;
 352
 353 out:
 354         free_dentry_path(page);
 355         free_xid(xid);
 356         cifs_put_tlink(tlink);
 357         return rc;
 358 }
 359
 360 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
 361 {
 362         ssize_t rc = -EOPNOTSUPP;
 363         unsigned int xid;
 364         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 365         struct tcon_link *tlink;
 366         struct cifs_tcon *pTcon;
 367         const char *full_path;
 368         void *page;
 369
 370         if (unlikely(cifs_forced_shutdown(cifs_sb)))
 371                 return -EIO;
 372
 373         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 374                 return -EOPNOTSUPP;
 375
 376         tlink = cifs_sb_tlink(cifs_sb);
 377         if (IS_ERR(tlink))
 378                 return PTR_ERR(tlink);
 379         pTcon = tlink_tcon(tlink);
 380
 381         xid = get_xid();
 382         page = alloc_dentry_path();
 383
 384         full_path = build_path_from_dentry(direntry, page);
 385         if (IS_ERR(full_path)) {
 386                 rc = PTR_ERR(full_path);
 387                 goto list_ea_exit;
 388         }
 389         /* return dos attributes as pseudo xattr */
 390         /* return alt name if available as pseudo attr */
 391
 392         /* if proc/fs/cifs/streamstoxattr is set then
 393                 search server for EAs or streams to
 394                 returns as xattrs */
 395
 396         if (pTcon->ses->server->ops->query_all_EAs)
 397                 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 398                                 full_path, NULL, data, buf_size, cifs_sb);
 399 list_ea_exit:
 400         free_dentry_path(page);
 401         free_xid(xid);
 402         cifs_put_tlink(tlink);
 403         return rc;
 404 }
 405
 406 static const struct xattr_handler cifs_user_xattr_handler = {
 407         .prefix = XATTR_USER_PREFIX,
 408         .flags = XATTR_USER,
 409         .get = cifs_xattr_get,
 410         .set = cifs_xattr_set,
 411 };
 412
 413 /* os2.* attributes are treated like user.* attributes */
 414 static const struct xattr_handler cifs_os2_xattr_handler = {
 415         .prefix = XATTR_OS2_PREFIX,
 416         .flags = XATTR_USER,
 417         .get = cifs_xattr_get,
 418         .set = cifs_xattr_set,
 419 };
 420
 421 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
 422         .name = CIFS_XATTR_CIFS_ACL,
 423         .flags = XATTR_CIFS_ACL,
 424         .get = cifs_xattr_get,
 425         .set = cifs_xattr_set,
 426 };
 427
 428 /*
 429  * Although this is just an alias for the above, need to move away from
 430  * confusing users and using the 20 year old term 'cifs' when it is no
 431  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 432  * SMB3 and later are highly secure.
 433  */
 434 static const struct xattr_handler smb3_acl_xattr_handler = {
 435         .name = SMB3_XATTR_CIFS_ACL,
 436         .flags = XATTR_CIFS_ACL,
 437         .get = cifs_xattr_get,
 438         .set = cifs_xattr_set,
 439 };
 440
 441 static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
 442         .name = CIFS_XATTR_CIFS_NTSD,
 443         .flags = XATTR_CIFS_NTSD,
 444         .get = cifs_xattr_get,
 445         .set = cifs_xattr_set,
 446 };
 447
 448 /*
 449  * Although this is just an alias for the above, need to move away from
 450  * confusing users and using the 20 year old term 'cifs' when it is no
 451  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 452  * SMB3 and later are highly secure.
 453  */
 454 static const struct xattr_handler smb3_ntsd_xattr_handler = {
 455         .name = SMB3_XATTR_CIFS_NTSD,
 456         .flags = XATTR_CIFS_NTSD,
 457         .get = cifs_xattr_get,
 458         .set = cifs_xattr_set,
 459 };
 460
 461 static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
 462         .name = CIFS_XATTR_CIFS_NTSD_FULL,
 463         .flags = XATTR_CIFS_NTSD_FULL,
 464         .get = cifs_xattr_get,
 465         .set = cifs_xattr_set,
 466 };
 467
 468 /*
 469  * Although this is just an alias for the above, need to move away from
 470  * confusing users and using the 20 year old term 'cifs' when it is no
 471  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 472  * SMB3 and later are highly secure.
 473  */
 474 static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
 475         .name = SMB3_XATTR_CIFS_NTSD_FULL,
 476         .flags = XATTR_CIFS_NTSD_FULL,
 477         .get = cifs_xattr_get,
 478         .set = cifs_xattr_set,
 479 };
 480
 481 const struct xattr_handler *cifs_xattr_handlers[] = {
 482         &cifs_user_xattr_handler,
 483         &cifs_os2_xattr_handler,
 484         &cifs_cifs_acl_xattr_handler,
 485         &smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
 486         &cifs_cifs_ntsd_xattr_handler,
 487         &smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
 488         &cifs_cifs_ntsd_full_xattr_handler,
 489         &smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
 490         NULL
 491 };