source3/modules/vfs_xattr_tdb.c

   1 /*
   2  * Store posix-level xattrs in a tdb
   3  *
   4  * Copyright (C) Volker Lendecke, 2007
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "includes.h"
  21 #include "system/filesys.h"
  22 #include "smbd/smbd.h"
  23 #include "dbwrap/dbwrap.h"
  24 #include "dbwrap/dbwrap_open.h"
  25 #include "source3/lib/xattr_tdb.h"
  26
  27 #undef DBGC_CLASS
  28 #define DBGC_CLASS DBGC_VFS
  29
  30 static ssize_t xattr_tdb_getxattr(struct vfs_handle_struct *handle,
  31                                   const char *path, const char *name,
  32                                   void *value, size_t size)
  33 {
  34         SMB_STRUCT_STAT sbuf;
  35         struct file_id id;
  36         struct db_context *db;
  37         ssize_t xattr_size;
  38         DATA_BLOB blob;
  39         TALLOC_CTX *frame = talloc_stackframe();
  40
  41         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
  42
  43         if (vfs_stat_smb_fname(handle->conn, path, &sbuf) == -1) {
  44                 TALLOC_FREE(frame);
  45                 return -1;
  46         }
  47
  48         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
  49
  50         xattr_size = xattr_tdb_getattr(db, frame, &id, name, &blob);
  51         if (xattr_size < 0) {
  52                 TALLOC_FREE(frame);
  53                 return -1;
  54         }
  55         if (blob.length > size) {
  56                 TALLOC_FREE(frame);
  57                 errno = ERANGE;
  58                 return -1;
  59         }
  60         memcpy(value, blob.data, size);
  61         return xattr_size;
  62 }
  63
  64 static ssize_t xattr_tdb_fgetxattr(struct vfs_handle_struct *handle,
  65                                    struct files_struct *fsp,
  66                                    const char *name, void *value, size_t size)
  67 {
  68         SMB_STRUCT_STAT sbuf;
  69         struct file_id id;
  70         struct db_context *db;
  71         ssize_t xattr_size;
  72         DATA_BLOB blob;
  73         TALLOC_CTX *frame = talloc_stackframe();
  74
  75         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
  76
  77         if (SMB_VFS_FSTAT(fsp, &sbuf) == -1) {
  78                 TALLOC_FREE(frame);
  79                 return -1;
  80         }
  81
  82         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
  83
  84         xattr_size = xattr_tdb_getattr(db, frame, &id, name, &blob);
  85         if (xattr_size < 0) {
  86                 TALLOC_FREE(frame);
  87                 return -1;
  88         }
  89         if (blob.length > size) {
  90                 TALLOC_FREE(frame);
  91                 errno = ERANGE;
  92                 return -1;
  93         }
  94         memcpy(value, blob.data, size);
  95         TALLOC_FREE(frame);
  96         return xattr_size;
  97 }
  98
  99 static int xattr_tdb_setxattr(struct vfs_handle_struct *handle,
 100                               const char *path, const char *name,
 101                               const void *value, size_t size, int flags)
 102 {
 103         SMB_STRUCT_STAT sbuf;
 104         struct file_id id;
 105         struct db_context *db;
 106
 107         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 108
 109         if (vfs_stat_smb_fname(handle->conn, path, &sbuf) == -1) {
 110                 return -1;
 111         }
 112
 113         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 114
 115         return xattr_tdb_setattr(db, &id, name, value, size, flags);
 116 }
 117
 118 static int xattr_tdb_fsetxattr(struct vfs_handle_struct *handle,
 119                                struct files_struct *fsp,
 120                                const char *name, const void *value,
 121                                size_t size, int flags)
 122 {
 123         SMB_STRUCT_STAT sbuf;
 124         struct file_id id;
 125         struct db_context *db;
 126
 127         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 128
 129         if (SMB_VFS_FSTAT(fsp, &sbuf) == -1) {
 130                 return -1;
 131         }
 132
 133         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 134
 135         return xattr_tdb_setattr(db, &id, name, value, size, flags);
 136 }
 137
 138 static ssize_t xattr_tdb_listxattr(struct vfs_handle_struct *handle,
 139                                    const char *path, char *list, size_t size)
 140 {
 141         SMB_STRUCT_STAT sbuf;
 142         struct file_id id;
 143         struct db_context *db;
 144
 145         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 146
 147         if (vfs_stat_smb_fname(handle->conn, path, &sbuf) == -1) {
 148                 return -1;
 149         }
 150
 151         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 152
 153         return xattr_tdb_listattr(db, &id, list, size);
 154 }
 155
 156 static ssize_t xattr_tdb_flistxattr(struct vfs_handle_struct *handle,
 157                                     struct files_struct *fsp, char *list,
 158                                     size_t size)
 159 {
 160         SMB_STRUCT_STAT sbuf;
 161         struct file_id id;
 162         struct db_context *db;
 163
 164         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 165
 166         if (SMB_VFS_FSTAT(fsp, &sbuf) == -1) {
 167                 return -1;
 168         }
 169
 170         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 171
 172         return xattr_tdb_listattr(db, &id, list, size);
 173 }
 174
 175 static int xattr_tdb_removexattr(struct vfs_handle_struct *handle,
 176                                  const char *path, const char *name)
 177 {
 178         SMB_STRUCT_STAT sbuf;
 179         struct file_id id;
 180         struct db_context *db;
 181
 182         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 183
 184         if (vfs_stat_smb_fname(handle->conn, path, &sbuf) == -1) {
 185                 return -1;
 186         }
 187
 188         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 189
 190         return xattr_tdb_removeattr(db, &id, name);
 191 }
 192
 193 static int xattr_tdb_fremovexattr(struct vfs_handle_struct *handle,
 194                                   struct files_struct *fsp, const char *name)
 195 {
 196         SMB_STRUCT_STAT sbuf;
 197         struct file_id id;
 198         struct db_context *db;
 199
 200         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 201
 202         if (SMB_VFS_FSTAT(fsp, &sbuf) == -1) {
 203                 return -1;
 204         }
 205
 206         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 207
 208         return xattr_tdb_removeattr(db, &id, name);
 209 }
 210
 211 /*
 212  * Open the tdb file upon VFS_CONNECT
 213  */
 214
 215 static bool xattr_tdb_init(int snum, struct db_context **p_db)
 216 {
 217         struct db_context *db;
 218         const char *dbname;
 219         char *def_dbname;
 220
 221         def_dbname = state_path("xattr.tdb");
 222         if (def_dbname == NULL) {
 223                 errno = ENOSYS;
 224                 return false;
 225         }
 226
 227         dbname = lp_parm_const_string(snum, "xattr_tdb", "file", def_dbname);
 228
 229         /* now we know dbname is not NULL */
 230
 231         become_root();
 232         db = db_open(NULL, dbname, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600,
 233                      DBWRAP_LOCK_ORDER_2);
 234         unbecome_root();
 235
 236         if (db == NULL) {
 237 #if defined(ENOTSUP)
 238                 errno = ENOTSUP;
 239 #else
 240                 errno = ENOSYS;
 241 #endif
 242                 TALLOC_FREE(def_dbname);
 243                 return false;
 244         }
 245
 246         *p_db = db;
 247         TALLOC_FREE(def_dbname);
 248         return true;
 249 }
 250
 251 /*
 252  * On unlink we need to delete the tdb record
 253  */
 254 static int xattr_tdb_unlink(vfs_handle_struct *handle,
 255                             const struct smb_filename *smb_fname)
 256 {
 257         struct smb_filename *smb_fname_tmp = NULL;
 258         struct file_id id;
 259         struct db_context *db;
 260         NTSTATUS status;
 261         int ret = -1;
 262         bool remove_record = false;
 263
 264         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 265
 266         status = copy_smb_filename(talloc_tos(), smb_fname, &smb_fname_tmp);
 267         if (!NT_STATUS_IS_OK(status)) {
 268                 errno = map_errno_from_nt_status(status);
 269                 return -1;
 270         }
 271
 272         if (lp_posix_pathnames()) {
 273                 ret = SMB_VFS_LSTAT(handle->conn, smb_fname_tmp);
 274         } else {
 275                 ret = SMB_VFS_STAT(handle->conn, smb_fname_tmp);
 276         }
 277         if (ret == -1) {
 278                 goto out;
 279         }
 280
 281         if (smb_fname_tmp->st.st_ex_nlink == 1) {
 282                 /* Only remove record on last link to file. */
 283                 remove_record = true;
 284         }
 285
 286         ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname_tmp);
 287
 288         if (ret == -1) {
 289                 goto out;
 290         }
 291
 292         if (!remove_record) {
 293                 goto out;
 294         }
 295
 296         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &smb_fname_tmp->st);
 297
 298         xattr_tdb_remove_all_attrs(db, &id);
 299
 300  out:
 301         TALLOC_FREE(smb_fname_tmp);
 302         return ret;
 303 }
 304
 305 /*
 306  * On rmdir we need to delete the tdb record
 307  */
 308 static int xattr_tdb_rmdir(vfs_handle_struct *handle, const char *path)
 309 {
 310         SMB_STRUCT_STAT sbuf;
 311         struct file_id id;
 312         struct db_context *db;
 313         int ret;
 314
 315         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 316
 317         if (vfs_stat_smb_fname(handle->conn, path, &sbuf) == -1) {
 318                 return -1;
 319         }
 320
 321         ret = SMB_VFS_NEXT_RMDIR(handle, path);
 322
 323         if (ret == -1) {
 324                 return -1;
 325         }
 326
 327         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 328
 329         xattr_tdb_remove_all_attrs(db, &id);
 330
 331         return 0;
 332 }
 333
 334 /*
 335  * Destructor for the VFS private data
 336  */
 337
 338 static void close_xattr_db(void **data)
 339 {
 340         struct db_context **p_db = (struct db_context **)data;
 341         TALLOC_FREE(*p_db);
 342 }
 343
 344 static int xattr_tdb_connect(vfs_handle_struct *handle, const char *service,
 345                           const char *user)
 346 {
 347         char *sname = NULL;
 348         int res, snum;
 349         struct db_context *db;
 350
 351         res = SMB_VFS_NEXT_CONNECT(handle, service, user);
 352         if (res < 0) {
 353                 return res;
 354         }
 355
 356         snum = find_service(talloc_tos(), service, &sname);
 357         if (snum == -1 || sname == NULL) {
 358                 /*
 359                  * Should not happen, but we should not fail just *here*.
 360                  */
 361                 return 0;
 362         }
 363
 364         if (!xattr_tdb_init(snum, &db)) {
 365                 DEBUG(5, ("Could not init xattr tdb\n"));
 366                 lp_do_parameter(snum, "ea support", "False");
 367                 return 0;
 368         }
 369
 370         lp_do_parameter(snum, "ea support", "True");
 371
 372         SMB_VFS_HANDLE_SET_DATA(handle, db, close_xattr_db,
 373                                 struct db_context, return -1);
 374
 375         return 0;
 376 }
 377
 378 static struct vfs_fn_pointers vfs_xattr_tdb_fns = {
 379         .getxattr_fn = xattr_tdb_getxattr,
 380         .fgetxattr_fn = xattr_tdb_fgetxattr,
 381         .setxattr_fn = xattr_tdb_setxattr,
 382         .fsetxattr_fn = xattr_tdb_fsetxattr,
 383         .listxattr_fn = xattr_tdb_listxattr,
 384         .flistxattr_fn = xattr_tdb_flistxattr,
 385         .removexattr_fn = xattr_tdb_removexattr,
 386         .fremovexattr_fn = xattr_tdb_fremovexattr,
 387         .unlink_fn = xattr_tdb_unlink,
 388         .rmdir_fn = xattr_tdb_rmdir,
 389         .connect_fn = xattr_tdb_connect,
 390 };
 391
 392 NTSTATUS vfs_xattr_tdb_init(void);
 393 NTSTATUS vfs_xattr_tdb_init(void)
 394 {
 395         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "xattr_tdb",
 396                                 &vfs_xattr_tdb_fns);
 397 }