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,
  42                                 TALLOC_FREE(frame); return -1);
  43
  44         if (vfs_stat_smb_fname(handle->conn, path, &sbuf) == -1) {
  45                 TALLOC_FREE(frame);
  46                 return -1;
  47         }
  48
  49         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
  50
  51         xattr_size = xattr_tdb_getattr(db, frame, &id, name, &blob);
  52         if (xattr_size < 0) {
  53                 TALLOC_FREE(frame);
  54                 return -1;
  55         }
  56         if (blob.length > size) {
  57                 TALLOC_FREE(frame);
  58                 errno = ERANGE;
  59                 return -1;
  60         }
  61         memcpy(value, blob.data, xattr_size);
  62         TALLOC_FREE(frame);
  63         return xattr_size;
  64 }
  65
  66 static ssize_t xattr_tdb_fgetxattr(struct vfs_handle_struct *handle,
  67                                    struct files_struct *fsp,
  68                                    const char *name, void *value, size_t size)
  69 {
  70         SMB_STRUCT_STAT sbuf;
  71         struct file_id id;
  72         struct db_context *db;
  73         ssize_t xattr_size;
  74         DATA_BLOB blob;
  75         TALLOC_CTX *frame = talloc_stackframe();
  76
  77         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, TALLOC_FREE(frame); return -1);
  78
  79         if (SMB_VFS_FSTAT(fsp, &sbuf) == -1) {
  80                 TALLOC_FREE(frame);
  81                 return -1;
  82         }
  83
  84         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
  85
  86         xattr_size = xattr_tdb_getattr(db, frame, &id, name, &blob);
  87         if (xattr_size < 0) {
  88                 TALLOC_FREE(frame);
  89                 return -1;
  90         }
  91         if (blob.length > size) {
  92                 TALLOC_FREE(frame);
  93                 errno = ERANGE;
  94                 return -1;
  95         }
  96         memcpy(value, blob.data, xattr_size);
  97         TALLOC_FREE(frame);
  98         return xattr_size;
  99 }
 100
 101 static int xattr_tdb_setxattr(struct vfs_handle_struct *handle,
 102                               const char *path, const char *name,
 103                               const void *value, size_t size, int flags)
 104 {
 105         SMB_STRUCT_STAT sbuf;
 106         struct file_id id;
 107         struct db_context *db;
 108
 109         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 110
 111         if (vfs_stat_smb_fname(handle->conn, path, &sbuf) == -1) {
 112                 return -1;
 113         }
 114
 115         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 116
 117         return xattr_tdb_setattr(db, &id, name, value, size, flags);
 118 }
 119
 120 static int xattr_tdb_fsetxattr(struct vfs_handle_struct *handle,
 121                                struct files_struct *fsp,
 122                                const char *name, const void *value,
 123                                size_t size, int flags)
 124 {
 125         SMB_STRUCT_STAT sbuf;
 126         struct file_id id;
 127         struct db_context *db;
 128
 129         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 130
 131         if (SMB_VFS_FSTAT(fsp, &sbuf) == -1) {
 132                 return -1;
 133         }
 134
 135         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 136
 137         return xattr_tdb_setattr(db, &id, name, value, size, flags);
 138 }
 139
 140 static ssize_t xattr_tdb_listxattr(struct vfs_handle_struct *handle,
 141                                    const char *path, char *list, size_t size)
 142 {
 143         SMB_STRUCT_STAT sbuf;
 144         struct file_id id;
 145         struct db_context *db;
 146
 147         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 148
 149         if (vfs_stat_smb_fname(handle->conn, path, &sbuf) == -1) {
 150                 return -1;
 151         }
 152
 153         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 154
 155         return xattr_tdb_listattr(db, &id, list, size);
 156 }
 157
 158 static ssize_t xattr_tdb_flistxattr(struct vfs_handle_struct *handle,
 159                                     struct files_struct *fsp, char *list,
 160                                     size_t size)
 161 {
 162         SMB_STRUCT_STAT sbuf;
 163         struct file_id id;
 164         struct db_context *db;
 165
 166         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 167
 168         if (SMB_VFS_FSTAT(fsp, &sbuf) == -1) {
 169                 return -1;
 170         }
 171
 172         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 173
 174         return xattr_tdb_listattr(db, &id, list, size);
 175 }
 176
 177 static int xattr_tdb_removexattr(struct vfs_handle_struct *handle,
 178                                  const char *path, const char *name)
 179 {
 180         SMB_STRUCT_STAT sbuf;
 181         struct file_id id;
 182         struct db_context *db;
 183
 184         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 185
 186         if (vfs_stat_smb_fname(handle->conn, path, &sbuf) == -1) {
 187                 return -1;
 188         }
 189
 190         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 191
 192         return xattr_tdb_removeattr(db, &id, name);
 193 }
 194
 195 static int xattr_tdb_fremovexattr(struct vfs_handle_struct *handle,
 196                                   struct files_struct *fsp, const char *name)
 197 {
 198         SMB_STRUCT_STAT sbuf;
 199         struct file_id id;
 200         struct db_context *db;
 201
 202         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 203
 204         if (SMB_VFS_FSTAT(fsp, &sbuf) == -1) {
 205                 return -1;
 206         }
 207
 208         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 209
 210         return xattr_tdb_removeattr(db, &id, name);
 211 }
 212
 213 /*
 214  * Open the tdb file upon VFS_CONNECT
 215  */
 216
 217 static bool xattr_tdb_init(int snum, struct db_context **p_db)
 218 {
 219         struct db_context *db;
 220         const char *dbname;
 221         char *def_dbname;
 222
 223         def_dbname = state_path("xattr.tdb");
 224         if (def_dbname == NULL) {
 225                 errno = ENOSYS;
 226                 return false;
 227         }
 228
 229         dbname = lp_parm_const_string(snum, "xattr_tdb", "file", def_dbname);
 230
 231         /* now we know dbname is not NULL */
 232
 233         become_root();
 234         db = db_open(NULL, dbname, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600,
 235                      DBWRAP_LOCK_ORDER_2);
 236         unbecome_root();
 237
 238         if (db == NULL) {
 239 #if defined(ENOTSUP)
 240                 errno = ENOTSUP;
 241 #else
 242                 errno = ENOSYS;
 243 #endif
 244                 TALLOC_FREE(def_dbname);
 245                 return false;
 246         }
 247
 248         *p_db = db;
 249         TALLOC_FREE(def_dbname);
 250         return true;
 251 }
 252
 253 /*
 254  * On unlink we need to delete the tdb record
 255  */
 256 static int xattr_tdb_unlink(vfs_handle_struct *handle,
 257                             const struct smb_filename *smb_fname)
 258 {
 259         struct smb_filename *smb_fname_tmp = NULL;
 260         struct file_id id;
 261         struct db_context *db;
 262         NTSTATUS status;
 263         int ret = -1;
 264         bool remove_record = false;
 265
 266         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 267
 268         status = copy_smb_filename(talloc_tos(), smb_fname, &smb_fname_tmp);
 269         if (!NT_STATUS_IS_OK(status)) {
 270                 errno = map_errno_from_nt_status(status);
 271                 return -1;
 272         }
 273
 274         if (lp_posix_pathnames()) {
 275                 ret = SMB_VFS_LSTAT(handle->conn, smb_fname_tmp);
 276         } else {
 277                 ret = SMB_VFS_STAT(handle->conn, smb_fname_tmp);
 278         }
 279         if (ret == -1) {
 280                 goto out;
 281         }
 282
 283         if (smb_fname_tmp->st.st_ex_nlink == 1) {
 284                 /* Only remove record on last link to file. */
 285                 remove_record = true;
 286         }
 287
 288         ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname_tmp);
 289
 290         if (ret == -1) {
 291                 goto out;
 292         }
 293
 294         if (!remove_record) {
 295                 goto out;
 296         }
 297
 298         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &smb_fname_tmp->st);
 299
 300         xattr_tdb_remove_all_attrs(db, &id);
 301
 302  out:
 303         TALLOC_FREE(smb_fname_tmp);
 304         return ret;
 305 }
 306
 307 /*
 308  * On rmdir we need to delete the tdb record
 309  */
 310 static int xattr_tdb_rmdir(vfs_handle_struct *handle, const char *path)
 311 {
 312         SMB_STRUCT_STAT sbuf;
 313         struct file_id id;
 314         struct db_context *db;
 315         int ret;
 316
 317         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context, return -1);
 318
 319         if (vfs_stat_smb_fname(handle->conn, path, &sbuf) == -1) {
 320                 return -1;
 321         }
 322
 323         ret = SMB_VFS_NEXT_RMDIR(handle, path);
 324
 325         if (ret == -1) {
 326                 return -1;
 327         }
 328
 329         id = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
 330
 331         xattr_tdb_remove_all_attrs(db, &id);
 332
 333         return 0;
 334 }
 335
 336 /*
 337  * Destructor for the VFS private data
 338  */
 339
 340 static void close_xattr_db(void **data)
 341 {
 342         struct db_context **p_db = (struct db_context **)data;
 343         TALLOC_FREE(*p_db);
 344 }
 345
 346 static int xattr_tdb_connect(vfs_handle_struct *handle, const char *service,
 347                           const char *user)
 348 {
 349         char *sname = NULL;
 350         int res, snum;
 351         struct db_context *db;
 352
 353         res = SMB_VFS_NEXT_CONNECT(handle, service, user);
 354         if (res < 0) {
 355                 return res;
 356         }
 357
 358         snum = find_service(talloc_tos(), service, &sname);
 359         if (snum == -1 || sname == NULL) {
 360                 /*
 361                  * Should not happen, but we should not fail just *here*.
 362                  */
 363                 return 0;
 364         }
 365
 366         if (!xattr_tdb_init(snum, &db)) {
 367                 DEBUG(5, ("Could not init xattr tdb\n"));
 368                 lp_do_parameter(snum, "ea support", "False");
 369                 return 0;
 370         }
 371
 372         lp_do_parameter(snum, "ea support", "True");
 373
 374         SMB_VFS_HANDLE_SET_DATA(handle, db, close_xattr_db,
 375                                 struct db_context, return -1);
 376
 377         return 0;
 378 }
 379
 380 static struct vfs_fn_pointers vfs_xattr_tdb_fns = {
 381         .getxattr_fn = xattr_tdb_getxattr,
 382         .fgetxattr_fn = xattr_tdb_fgetxattr,
 383         .setxattr_fn = xattr_tdb_setxattr,
 384         .fsetxattr_fn = xattr_tdb_fsetxattr,
 385         .listxattr_fn = xattr_tdb_listxattr,
 386         .flistxattr_fn = xattr_tdb_flistxattr,
 387         .removexattr_fn = xattr_tdb_removexattr,
 388         .fremovexattr_fn = xattr_tdb_fremovexattr,
 389         .unlink_fn = xattr_tdb_unlink,
 390         .rmdir_fn = xattr_tdb_rmdir,
 391         .connect_fn = xattr_tdb_connect,
 392 };
 393
 394 NTSTATUS vfs_xattr_tdb_init(void);
 395 NTSTATUS vfs_xattr_tdb_init(void)
 396 {
 397         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "xattr_tdb",
 398                                 &vfs_xattr_tdb_fns);
 399 }