source3/smbd/durable.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Durable Handle default VFS implementation
   4
   5    Copyright (C) Stefan Metzmacher 2012
   6    Copyright (C) Michael Adam 2012
   7    Copyright (C) Volker Lendecke 2012
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "system/filesys.h"
  25 #include "smbd/smbd.h"
  26 #include "smbd/globals.h"
  27 #include "libcli/security/security.h"
  28 #include "messages.h"
  29 #include "librpc/gen_ndr/ndr_open_files.h"
  30 #include "serverid.h"
  31 #include "fake_file.h"
  32
  33 NTSTATUS vfs_default_durable_cookie(struct files_struct *fsp,
  34                                     TALLOC_CTX *mem_ctx,
  35                                     DATA_BLOB *cookie_blob)
  36 {
  37         struct connection_struct *conn = fsp->conn;
  38         enum ndr_err_code ndr_err;
  39         struct vfs_default_durable_cookie cookie;
  40
  41         if (!lp_durable_handles(SNUM(conn))) {
  42                 return NT_STATUS_NOT_SUPPORTED;
  43         }
  44
  45         if (lp_kernel_share_modes(SNUM(conn))) {
  46                 /*
  47                  * We do not support durable handles
  48                  * if kernel share modes (flocks) are used
  49                  */
  50                 return NT_STATUS_NOT_SUPPORTED;
  51         }
  52
  53         if (lp_kernel_oplocks(SNUM(conn))) {
  54                 /*
  55                  * We do not support durable handles
  56                  * if kernel oplocks are used
  57                  */
  58                 return NT_STATUS_NOT_SUPPORTED;
  59         }
  60
  61         if ((fsp->current_lock_count > 0) &&
  62             lp_posix_locking(fsp->conn->params))
  63         {
  64                 /*
  65                  * We do not support durable handles
  66                  * if the handle has posix locks.
  67                  */
  68                 return NT_STATUS_NOT_SUPPORTED;
  69         }
  70
  71         if (fsp->is_directory) {
  72                 return NT_STATUS_NOT_SUPPORTED;
  73         }
  74
  75         if (fsp->fh->fd == -1) {
  76                 return NT_STATUS_NOT_SUPPORTED;
  77         }
  78
  79         if (is_ntfs_stream_smb_fname(fsp->fsp_name)) {
  80                 /*
  81                  * We do not support durable handles
  82                  * on streams for now.
  83                  */
  84                 return NT_STATUS_NOT_SUPPORTED;
  85         }
  86
  87         if (is_fake_file(fsp->fsp_name)) {
  88                 /*
  89                  * We do not support durable handles
  90                  * on fake files.
  91                  */
  92                 return NT_STATUS_NOT_SUPPORTED;
  93         }
  94
  95         ZERO_STRUCT(cookie);
  96         cookie.allow_reconnect = false;
  97         cookie.id = fsp->file_id;
  98         cookie.servicepath = conn->connectpath;
  99         cookie.base_name = fsp->fsp_name->base_name;
 100         cookie.initial_allocation_size = fsp->initial_allocation_size;
 101         cookie.position_information = fsp->fh->position_information;
 102
 103         ndr_err = ndr_push_struct_blob(cookie_blob, mem_ctx, &cookie,
 104                         (ndr_push_flags_fn_t)ndr_push_vfs_default_durable_cookie);
 105         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 106                 NTSTATUS status = ndr_map_error2ntstatus(ndr_err);
 107                 return status;
 108         }
 109
 110         return NT_STATUS_OK;
 111 }
 112
 113 NTSTATUS vfs_default_durable_disconnect(struct files_struct *fsp,
 114                                         const DATA_BLOB old_cookie,
 115                                         TALLOC_CTX *mem_ctx,
 116                                         DATA_BLOB *new_cookie)
 117 {
 118         struct connection_struct *conn = fsp->conn;
 119         NTSTATUS status;
 120         enum ndr_err_code ndr_err;
 121         struct vfs_default_durable_cookie cookie;
 122         DATA_BLOB new_cookie_blob = data_blob_null;
 123         struct share_mode_lock *lck;
 124         bool ok;
 125
 126         *new_cookie = data_blob_null;
 127
 128         ZERO_STRUCT(cookie);
 129
 130         ndr_err = ndr_pull_struct_blob(&old_cookie, talloc_tos(), &cookie,
 131                         (ndr_pull_flags_fn_t)ndr_pull_vfs_default_durable_cookie);
 132         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 133                 status = ndr_map_error2ntstatus(ndr_err);
 134                 return status;
 135         }
 136
 137         if (strcmp(cookie.magic, VFS_DEFAULT_DURABLE_COOKIE_MAGIC) != 0) {
 138                 return NT_STATUS_INVALID_PARAMETER;
 139         }
 140
 141         if (cookie.version != VFS_DEFAULT_DURABLE_COOKIE_VERSION) {
 142                 return NT_STATUS_INVALID_PARAMETER;
 143         }
 144
 145         if (!file_id_equal(&fsp->file_id, &cookie.id)) {
 146                 return NT_STATUS_INVALID_PARAMETER;
 147         }
 148
 149         if (!BATCH_OPLOCK_TYPE(fsp->oplock_type)) {
 150                 return NT_STATUS_NOT_SUPPORTED;
 151         }
 152
 153         if (fsp->num_pending_break_messages > 0) {
 154                 return NT_STATUS_NOT_SUPPORTED;
 155         }
 156
 157         /*
 158          * For now let it be simple and do not keep
 159          * delete on close files durable open
 160          */
 161         if (fsp->initial_delete_on_close) {
 162                 return NT_STATUS_NOT_SUPPORTED;
 163         }
 164         if (fsp->delete_on_close) {
 165                 return NT_STATUS_NOT_SUPPORTED;
 166         }
 167
 168         if (!VALID_STAT(fsp->fsp_name->st)) {
 169                 return NT_STATUS_NOT_SUPPORTED;
 170         }
 171
 172         if (!S_ISREG(fsp->fsp_name->st.st_ex_mode)) {
 173                 return NT_STATUS_NOT_SUPPORTED;
 174         }
 175
 176         /*
 177          * The above checks are done in mark_share_mode_disconnected() too
 178          * but we want to avoid getting the lock if possible
 179          */
 180         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 181         if (lck != NULL) {
 182                 ok = mark_share_mode_disconnected(lck, fsp);
 183                 if (!ok) {
 184                         TALLOC_FREE(lck);
 185                 }
 186         }
 187         if (lck != NULL) {
 188                 ok = brl_mark_disconnected(fsp);
 189                 if (!ok) {
 190                         TALLOC_FREE(lck);
 191                 }
 192         }
 193         if (lck == NULL) {
 194                 return NT_STATUS_NOT_SUPPORTED;
 195         }
 196         TALLOC_FREE(lck);
 197
 198         ZERO_STRUCT(cookie);
 199         cookie.allow_reconnect = true;
 200         cookie.id = fsp->file_id;
 201         cookie.servicepath = conn->connectpath;
 202         cookie.base_name = fsp->fsp_name->base_name;
 203         cookie.initial_allocation_size = fsp->initial_allocation_size;
 204         cookie.position_information = fsp->fh->position_information;
 205
 206         ndr_err = ndr_push_struct_blob(&new_cookie_blob, mem_ctx, &cookie,
 207                         (ndr_push_flags_fn_t)ndr_push_vfs_default_durable_cookie);
 208         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 209                 status = ndr_map_error2ntstatus(ndr_err);
 210                 return status;
 211         }
 212
 213         status = fd_close(fsp);
 214         if (!NT_STATUS_IS_OK(status)) {
 215                 data_blob_free(&new_cookie_blob);
 216                 return status;
 217         }
 218
 219         *new_cookie = new_cookie_blob;
 220         return NT_STATUS_OK;
 221 }
 222
 223 NTSTATUS vfs_default_durable_reconnect(struct connection_struct *conn,
 224                                        struct smb_request *smb1req,
 225                                        struct smbXsrv_open *op,
 226                                        const DATA_BLOB old_cookie,
 227                                        TALLOC_CTX *mem_ctx,
 228                                        files_struct **result,
 229                                        DATA_BLOB *new_cookie)
 230 {
 231         struct share_mode_lock *lck;
 232         struct share_mode_entry *e;
 233         struct files_struct *fsp = NULL;
 234         NTSTATUS status;
 235         bool ok;
 236         int ret;
 237         int flags = 0;
 238         struct file_id file_id;
 239         struct smb_filename *smb_fname = NULL;
 240         enum ndr_err_code ndr_err;
 241         struct vfs_default_durable_cookie cookie;
 242         DATA_BLOB new_cookie_blob = data_blob_null;
 243
 244         *result = NULL;
 245         *new_cookie = data_blob_null;
 246
 247         if (!lp_durable_handles(SNUM(conn))) {
 248                 return NT_STATUS_NOT_SUPPORTED;
 249         }
 250
 251         /*
 252          * the checks for kernel oplocks
 253          * and similar things are done
 254          * in the vfs_default_durable_cookie()
 255          * call below.
 256          */
 257
 258         ZERO_STRUCT(cookie);
 259
 260         ndr_err = ndr_pull_struct_blob(&old_cookie, talloc_tos(), &cookie,
 261                         (ndr_pull_flags_fn_t)ndr_pull_vfs_default_durable_cookie);
 262         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 263                 status = ndr_map_error2ntstatus(ndr_err);
 264                 return status;
 265         }
 266
 267         if (strcmp(cookie.magic, VFS_DEFAULT_DURABLE_COOKIE_MAGIC) != 0) {
 268                 return NT_STATUS_INVALID_PARAMETER;
 269         }
 270
 271         if (cookie.version != VFS_DEFAULT_DURABLE_COOKIE_VERSION) {
 272                 return NT_STATUS_INVALID_PARAMETER;
 273         }
 274
 275         if (!cookie.allow_reconnect) {
 276                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 277         }
 278
 279         if (strcmp(cookie.servicepath, conn->connectpath) != 0) {
 280                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 281         }
 282
 283         /* Create an smb_filename with stream_name == NULL. */
 284         status = create_synthetic_smb_fname(talloc_tos(),
 285                                             cookie.base_name,
 286                                             NULL, NULL,
 287                                             &smb_fname);
 288         if (!NT_STATUS_IS_OK(status)) {
 289                 return status;
 290         }
 291
 292         ret = SMB_VFS_LSTAT(conn, smb_fname);
 293         if (ret == -1) {
 294                 status = map_nt_error_from_unix_common(errno);
 295                 DEBUG(1, ("Unable to lstat stream: %s => %s\n",
 296                           smb_fname_str_dbg(smb_fname),
 297                           nt_errstr(status)));
 298                 return status;
 299         }
 300
 301         if (!S_ISREG(smb_fname->st.st_ex_mode)) {
 302                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 303         }
 304
 305         file_id = vfs_file_id_from_sbuf(conn, &smb_fname->st);
 306         if (!file_id_equal(&cookie.id, &file_id)) {
 307                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 308         }
 309
 310         /*
 311          * 1. check entry in locking.tdb
 312          */
 313
 314         lck = get_existing_share_mode_lock(mem_ctx, file_id);
 315         if (lck == NULL) {
 316                 DEBUG(5, ("vfs_default_durable_reconnect: share-mode lock "
 317                            "not obtained from db\n"));
 318                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 319         }
 320
 321         if (lck->data->num_share_modes == 0) {
 322                 DEBUG(1, ("vfs_default_durable_reconnect: Error: no share-mode "
 323                           "entry in existing share mode lock\n"));
 324                 TALLOC_FREE(lck);
 325                 return NT_STATUS_INTERNAL_DB_ERROR;
 326         }
 327
 328         if (lck->data->num_share_modes > 1) {
 329                 /*
 330                  * It can't be durable if there is more than one handle
 331                  * on the file.
 332                  */
 333                 DEBUG(5, ("vfs_default_durable_reconnect: more than one "
 334                           "share-mode entry - can not be durable\n"));
 335                 TALLOC_FREE(lck);
 336                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 337         }
 338
 339         e = &lck->data->share_modes[0];
 340
 341         if (!server_id_is_disconnected(&e->pid)) {
 342                 DEBUG(5, ("vfs_default_durable_reconnect: denying durable "
 343                           "reconnect for handle that was not marked "
 344                           "disconnected (e.g. smbd or cluster node died)\n"));
 345                 TALLOC_FREE(lck);
 346                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 347         }
 348
 349         if (e->share_file_id != op->global->open_persistent_id) {
 350                 DEBUG(5, ("vfs_default_durable_reconnect: denying durable "
 351                           "share_file_id changed %llu != %llu"
 352                           "(e.g. another client had opened the file)\n",
 353                           (unsigned long long)e->share_file_id,
 354                           (unsigned long long)op->global->open_persistent_id));
 355                 TALLOC_FREE(lck);
 356                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 357         }
 358
 359         if ((e->access_mask & (FILE_WRITE_DATA|FILE_APPEND_DATA)) &&
 360             !CAN_WRITE(conn))
 361         {
 362                 DEBUG(5, ("vfs_default_durable_reconnect: denying durable "
 363                           "share[%s] is not writeable anymore\n",
 364                           lp_servicename(talloc_tos(), SNUM(conn))));
 365                 TALLOC_FREE(lck);
 366                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 367         }
 368
 369         /*
 370          * TODO:
 371          * add scavenger timer functionality
 372          *
 373          * For now we always allow the reconnect
 374          */
 375 #if 0
 376         expire_time = op->global->disconnect_time;
 377         expire_time += NTTIME_MAGIC(op->global->durable_timeout_msec);
 378         if (expire < now) {
 379                 //TODO reopen and close before telling the client...
 380         }
 381 #endif
 382
 383         /*
 384          * 2. proceed with opening file
 385          */
 386
 387         status = fsp_new(conn, conn, &fsp);
 388         if (!NT_STATUS_IS_OK(status)) {
 389                 DEBUG(0, ("vfs_default_durable_reconnect: failed to create "
 390                           "new fsp: %s\n", nt_errstr(status)));
 391                 TALLOC_FREE(lck);
 392                 return status;
 393         }
 394
 395         fsp->fh->private_options = e->private_options;
 396         fsp->fh->gen_id = smbXsrv_open_hash(op);
 397         fsp->file_id = file_id;
 398         fsp->file_pid = smb1req->smbpid;
 399         fsp->vuid = smb1req->vuid;
 400         fsp->open_time = e->time;
 401         fsp->access_mask = e->access_mask;
 402         fsp->share_access = e->share_access;
 403         fsp->can_read = ((fsp->access_mask & (FILE_READ_DATA)) != 0);
 404         fsp->can_write = ((fsp->access_mask & (FILE_WRITE_DATA|FILE_APPEND_DATA)) != 0);
 405
 406         /*
 407          * TODO:
 408          * Do we need to store the modified flag in the DB?
 409          * How to handle update_write_time and friends
 410          * during a disconnected client on a durable handle?
 411          */
 412         fsp->modified = false;
 413         /*
 414          * no durables for directories
 415          */
 416         fsp->is_directory = false;
 417         /*
 418          * For normal files, can_lock == !is_directory
 419          */
 420         fsp->can_lock = true;
 421         /*
 422          * We do not support aio write behind for smb2
 423          */
 424         fsp->aio_write_behind = false;
 425         fsp->oplock_type = e->op_type;
 426
 427         fsp->initial_allocation_size = cookie.initial_allocation_size;
 428         fsp->fh->position_information = cookie.position_information;
 429
 430         status = fsp_set_smb_fname(fsp, smb_fname);
 431         if (!NT_STATUS_IS_OK(status)) {
 432                 TALLOC_FREE(lck);
 433                 fsp_free(fsp);
 434                 DEBUG(0, ("vfs_default_durable_reconnect: "
 435                           "fsp_set_smb_fname failed: %s\n",
 436                           nt_errstr(status)));
 437                 return status;
 438         }
 439
 440         op->compat = fsp;
 441         fsp->op = op;
 442
 443         e->pid = messaging_server_id(conn->sconn->msg_ctx);
 444         e->op_mid = smb1req->mid;
 445         e->share_file_id = fsp->fh->gen_id;
 446
 447         ok = brl_reconnect_disconnected(fsp);
 448         if (!ok) {
 449                 status = NT_STATUS_INTERNAL_ERROR;
 450                 DEBUG(1, ("vfs_default_durable_reconnect: "
 451                           "failed to reopen brlocks: %s\n",
 452                           nt_errstr(status)));
 453                 TALLOC_FREE(lck);
 454                 op->compat = NULL;
 455                 fsp_free(fsp);
 456                 return status;
 457         }
 458
 459         /*
 460          * TODO: properly calculate open flags
 461          */
 462         if (fsp->can_write && fsp->can_read) {
 463                 flags = O_RDWR;
 464         } else if (fsp->can_write) {
 465                 flags = O_WRONLY;
 466         } else if (fsp->can_read) {
 467                 flags = O_RDONLY;
 468         }
 469
 470         status = fd_open(conn, fsp, flags, 0 /* mode */);
 471         if (!NT_STATUS_IS_OK(status)) {
 472                 TALLOC_FREE(lck);
 473                 DEBUG(1, ("vfs_default_durable_reconnect: failed to open "
 474                           "file: %s\n", nt_errstr(status)));
 475                 op->compat = NULL;
 476                 fsp_free(fsp);
 477                 return status;
 478         }
 479
 480         ret = SMB_VFS_FSTAT(fsp, &fsp->fsp_name->st);
 481         if (ret == -1) {
 482                 status = map_nt_error_from_unix_common(errno);
 483                 DEBUG(1, ("Unable to fstat stream: %s => %s\n",
 484                           smb_fname_str_dbg(smb_fname),
 485                           nt_errstr(status)));
 486                 ret = SMB_VFS_CLOSE(fsp);
 487                 if (ret == -1) {
 488                         DEBUG(0, ("vfs_default_durable_reconnect: "
 489                                   "SMB_VFS_CLOSE failed (%s) - leaking file "
 490                                   "descriptor\n", strerror(errno)));
 491                 }
 492                 TALLOC_FREE(lck);
 493                 op->compat = NULL;
 494                 fsp_free(fsp);
 495                 return status;
 496
 497         }
 498
 499         if (!S_ISREG(fsp->fsp_name->st.st_ex_mode)) {
 500                 ret = SMB_VFS_CLOSE(fsp);
 501                 if (ret == -1) {
 502                         DEBUG(0, ("vfs_default_durable_reconnect: "
 503                                   "SMB_VFS_CLOSE failed (%s) - leaking file "
 504                                   "descriptor\n", strerror(errno)));
 505                 }
 506                 TALLOC_FREE(lck);
 507                 op->compat = NULL;
 508                 fsp_free(fsp);
 509                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 510         }
 511
 512         file_id = vfs_file_id_from_sbuf(conn, &fsp->fsp_name->st);
 513         if (!file_id_equal(&cookie.id, &file_id)) {
 514                 ret = SMB_VFS_CLOSE(fsp);
 515                 if (ret == -1) {
 516                         DEBUG(0, ("vfs_default_durable_reconnect: "
 517                                   "SMB_VFS_CLOSE failed (%s) - leaking file "
 518                                   "descriptor\n", strerror(errno)));
 519                 }
 520                 TALLOC_FREE(lck);
 521                 op->compat = NULL;
 522                 fsp_free(fsp);
 523                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 524         }
 525
 526         status = set_file_oplock(fsp, e->op_type);
 527         if (!NT_STATUS_IS_OK(status)) {
 528                 DEBUG(1, ("vfs_default_durable_reconnect failed to set oplock "
 529                           "after opening file: %s\n", nt_errstr(status)));
 530                 ret = SMB_VFS_CLOSE(fsp);
 531                 if (ret == -1) {
 532                         DEBUG(0, ("vfs_default_durable_reconnect: "
 533                                   "SMB_VFS_CLOSE failed (%s) - leaking file "
 534                                   "descriptor\n", strerror(errno)));
 535                 }
 536                 TALLOC_FREE(lck);
 537                 op->compat = NULL;
 538                 fsp_free(fsp);
 539                 return status;
 540         }
 541
 542         status = vfs_default_durable_cookie(fsp, mem_ctx, &new_cookie_blob);
 543         if (!NT_STATUS_IS_OK(status)) {
 544                 TALLOC_FREE(lck);
 545                 DEBUG(1, ("vfs_default_durable_reconnect: "
 546                           "vfs_default_durable_cookie - %s\n",
 547                           nt_errstr(status)));
 548                 op->compat = NULL;
 549                 fsp_free(fsp);
 550                 return status;
 551         }
 552
 553         smb1req->chain_fsp = fsp;
 554         smb1req->smb2req->compat_chain_fsp = fsp;
 555
 556         DEBUG(10, ("vfs_default_durable_reconnect: opened file '%s'\n",
 557                    fsp_str_dbg(fsp)));
 558
 559         /*
 560          * release the sharemode lock: this writes the changes
 561          */
 562         lck->data->modified = true;
 563         TALLOC_FREE(lck);
 564
 565         *result = fsp;
 566         *new_cookie = new_cookie_blob;
 567
 568         return NT_STATUS_OK;
 569 }