1/* 2 Unix SMB/CIFS implementation. 3 change notify handling 4 Copyright (C) Andrew Tridgell 2000 5 Copyright (C) Jeremy Allison 1994-1998 6 Copyright (C) Volker Lendecke 2007 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program. If not, see <http://www.gnu.org/licenses/>. 20*/ 21 22#include "includes.h" 23#include "smbd/globals.h" 24 25struct notify_change_request { 26 struct notify_change_request *prev, *next; 27 struct files_struct *fsp; /* backpointer for cancel by mid */ 28 struct smb_request *req; 29 uint32 filter; 30 uint32 max_param; 31 void (*reply_fn)(struct smb_request *req, 32 NTSTATUS error_code, 33 uint8_t *buf, size_t len); 34 struct notify_mid_map *mid_map; 35 void *backend_data; 36}; 37 38static void notify_fsp(files_struct *fsp, uint32 action, const char *name); 39 40/* 41 * For NTCancel, we need to find the notify_change_request indexed by 42 * mid. Separate list here. 43 */ 44 45struct notify_mid_map { 46 struct notify_mid_map *prev, *next; 47 struct notify_change_request *req; 48 uint16 mid; 49}; 50 51static bool notify_change_record_identical(struct notify_change *c1, 52 struct notify_change *c2) 53{ 54 /* Note this is deliberately case sensitive. */ 55 if (c1->action == c2->action && 56 strcmp(c1->name, c2->name) == 0) { 57 return True; 58 } 59 return False; 60} 61 62static bool notify_marshall_changes(int num_changes, 63 uint32 max_offset, 64 struct notify_change *changes, 65 prs_struct *ps) 66{ 67 int i; 68 UNISTR uni_name; 69 70 if (num_changes == -1) { 71 return false; 72 } 73 74 uni_name.buffer = NULL; 75 76 for (i=0; i<num_changes; i++) { 77 struct notify_change *c; 78 size_t namelen; 79 int rem = 0; 80 uint32 u32_tmp; /* Temp arg to prs_uint32 to avoid 81 * signed/unsigned issues */ 82 83 /* Coalesce any identical records. */ 84 while (i+1 < num_changes && 85 notify_change_record_identical(&changes[i], 86 &changes[i+1])) { 87 i++; 88 } 89 90 c = &changes[i]; 91 92 if (!convert_string_talloc(talloc_tos(), CH_UNIX, CH_UTF16LE, 93 c->name, strlen(c->name)+1, &uni_name.buffer, 94 &namelen, True) || (uni_name.buffer == NULL)) { 95 goto fail; 96 } 97 98 namelen -= 2; /* Dump NULL termination */ 99 100 /* 101 * Offset to next entry, only if there is one 102 */ 103 104 u32_tmp = (i == num_changes-1) ? 0 : namelen + 12; 105 106 /* Align on 4-byte boundary according to MS-CIFS 2.2.7.4.2 */ 107 if ((rem = u32_tmp % 4 ) != 0) 108 u32_tmp += 4 - rem; 109 110 if (!prs_uint32("offset", ps, 1, &u32_tmp)) goto fail; 111 112 u32_tmp = c->action; 113 if (!prs_uint32("action", ps, 1, &u32_tmp)) goto fail; 114 115 u32_tmp = namelen; 116 if (!prs_uint32("namelen", ps, 1, &u32_tmp)) goto fail; 117 118 if (!prs_unistr("name", ps, 1, &uni_name)) goto fail; 119 120 /* 121 * Not NULL terminated, decrease by the 2 UCS2 \0 chars 122 */ 123 prs_set_offset(ps, prs_offset(ps)-2); 124 125 if (rem != 0) { 126 if (!prs_align_custom(ps, 4)) goto fail; 127 } 128 129 TALLOC_FREE(uni_name.buffer); 130 131 if (prs_offset(ps) > max_offset) { 132 /* Too much data for client. */ 133 DEBUG(10, ("Client only wanted %d bytes, trying to " 134 "marshall %d bytes\n", (int)max_offset, 135 (int)prs_offset(ps))); 136 return False; 137 } 138 } 139 140 return True; 141 142 fail: 143 TALLOC_FREE(uni_name.buffer); 144 return False; 145} 146 147/**************************************************************************** 148 Setup the common parts of the return packet and send it. 149*****************************************************************************/ 150 151void change_notify_reply(connection_struct *conn, 152 struct smb_request *req, 153 NTSTATUS error_code, 154 uint32_t max_param, 155 struct notify_change_buf *notify_buf, 156 void (*reply_fn)(struct smb_request *req, 157 NTSTATUS error_code, 158 uint8_t *buf, size_t len)) 159{ 160 prs_struct ps; 161 162 if (!NT_STATUS_IS_OK(error_code)) { 163 reply_fn(req, error_code, NULL, 0); 164 return; 165 } 166 167 if (max_param == 0 || notify_buf == NULL) { 168 reply_fn(req, NT_STATUS_OK, NULL, 0); 169 return; 170 } 171 172 prs_init_empty(&ps, NULL, MARSHALL); 173 174 if (!notify_marshall_changes(notify_buf->num_changes, max_param, 175 notify_buf->changes, &ps)) { 176 /* 177 * We exceed what the client is willing to accept. Send 178 * nothing. 179 */ 180 prs_mem_free(&ps); 181 prs_init_empty(&ps, NULL, MARSHALL); 182 } 183 184 reply_fn(req, NT_STATUS_OK, (uint8_t *)prs_data_p(&ps), prs_offset(&ps)); 185 186 prs_mem_free(&ps); 187 188 TALLOC_FREE(notify_buf->changes); 189 notify_buf->num_changes = 0; 190} 191 192static void notify_callback(void *private_data, const struct notify_event *e) 193{ 194 files_struct *fsp = (files_struct *)private_data; 195 DEBUG(10, ("notify_callback called for %s\n", fsp_str_dbg(fsp))); 196 notify_fsp(fsp, e->action, e->path); 197} 198 199NTSTATUS change_notify_create(struct files_struct *fsp, uint32 filter, 200 bool recursive) 201{ 202 char *fullpath; 203 struct notify_entry e; 204 NTSTATUS status; 205 206 SMB_ASSERT(fsp->notify == NULL); 207 208 if (!(fsp->notify = TALLOC_ZERO_P(NULL, struct notify_change_buf))) { 209 DEBUG(0, ("talloc failed\n")); 210 return NT_STATUS_NO_MEMORY; 211 } 212 213 /* Do notify operations on the base_name. */ 214 if (asprintf(&fullpath, "%s/%s", fsp->conn->connectpath, 215 fsp->fsp_name->base_name) == -1) { 216 DEBUG(0, ("asprintf failed\n")); 217 TALLOC_FREE(fsp->notify); 218 return NT_STATUS_NO_MEMORY; 219 } 220 221 ZERO_STRUCT(e); 222 e.path = fullpath; 223 e.dir_fd = fsp->fh->fd; 224 e.dir_id = fsp->file_id; 225 e.filter = filter; 226 e.subdir_filter = 0; 227 if (recursive) { 228 e.subdir_filter = filter; 229 } 230 231 status = notify_add(fsp->conn->notify_ctx, &e, notify_callback, fsp); 232 SAFE_FREE(fullpath); 233 234 return status; 235} 236 237NTSTATUS change_notify_add_request(struct smb_request *req, 238 uint32 max_param, 239 uint32 filter, bool recursive, 240 struct files_struct *fsp, 241 void (*reply_fn)(struct smb_request *req, 242 NTSTATUS error_code, 243 uint8_t *buf, size_t len)) 244{ 245 struct notify_change_request *request = NULL; 246 struct notify_mid_map *map = NULL; 247 struct smbd_server_connection *sconn = smbd_server_conn; 248 249 DEBUG(10, ("change_notify_add_request: Adding request for %s: " 250 "max_param = %d\n", fsp_str_dbg(fsp), (int)max_param)); 251 252 if (!(request = talloc(NULL, struct notify_change_request)) 253 || !(map = talloc(request, struct notify_mid_map))) { 254 TALLOC_FREE(request); 255 return NT_STATUS_NO_MEMORY; 256 } 257 258 request->mid_map = map; 259 map->req = request; 260 261 request->req = talloc_move(request, &req); 262 request->max_param = max_param; 263 request->filter = filter; 264 request->fsp = fsp; 265 request->reply_fn = reply_fn; 266 request->backend_data = NULL; 267 268 DLIST_ADD_END(fsp->notify->requests, request, 269 struct notify_change_request *); 270 271 map->mid = request->req->mid; 272 DLIST_ADD(sconn->smb1.notify_mid_maps, map); 273 274 return NT_STATUS_OK; 275} 276 277static void change_notify_remove_request(struct notify_change_request *remove_req) 278{ 279 files_struct *fsp; 280 struct notify_change_request *req; 281 struct smbd_server_connection *sconn = smbd_server_conn; 282 283 /* 284 * Paranoia checks, the fsp referenced must must have the request in 285 * its list of pending requests 286 */ 287 288 fsp = remove_req->fsp; 289 SMB_ASSERT(fsp->notify != NULL); 290 291 for (req = fsp->notify->requests; req; req = req->next) { 292 if (req == remove_req) { 293 break; 294 } 295 } 296 297 if (req == NULL) { 298 smb_panic("notify_req not found in fsp's requests"); 299 } 300 301 DLIST_REMOVE(fsp->notify->requests, req); 302 DLIST_REMOVE(sconn->smb1.notify_mid_maps, req->mid_map); 303 TALLOC_FREE(req); 304} 305 306/**************************************************************************** 307 Delete entries by mid from the change notify pending queue. Always send reply. 308*****************************************************************************/ 309 310void remove_pending_change_notify_requests_by_mid(uint16 mid) 311{ 312 struct notify_mid_map *map; 313 struct smbd_server_connection *sconn = smbd_server_conn; 314 315 for (map = sconn->smb1.notify_mid_maps; map; map = map->next) { 316 if (map->mid == mid) { 317 break; 318 } 319 } 320 321 if (map == NULL) { 322 return; 323 } 324 325 change_notify_reply(map->req->fsp->conn, map->req->req, 326 NT_STATUS_CANCELLED, 0, NULL, map->req->reply_fn); 327 change_notify_remove_request(map->req); 328} 329 330void smbd_notify_cancel_by_smbreq(struct smbd_server_connection *sconn, 331 const struct smb_request *smbreq) 332{ 333 struct notify_mid_map *map; 334 335 for (map = sconn->smb1.notify_mid_maps; map; map = map->next) { 336 if (map->req->req == smbreq) { 337 break; 338 } 339 } 340 341 if (map == NULL) { 342 return; 343 } 344 345 change_notify_reply(map->req->fsp->conn, map->req->req, 346 NT_STATUS_CANCELLED, 0, NULL, map->req->reply_fn); 347 change_notify_remove_request(map->req); 348} 349 350/**************************************************************************** 351 Delete entries by fnum from the change notify pending queue. 352*****************************************************************************/ 353 354void remove_pending_change_notify_requests_by_fid(files_struct *fsp, 355 NTSTATUS status) 356{ 357 if (fsp->notify == NULL) { 358 return; 359 } 360 361 while (fsp->notify->requests != NULL) { 362 change_notify_reply(fsp->conn, fsp->notify->requests->req, 363 status, 0, NULL, 364 fsp->notify->requests->reply_fn); 365 change_notify_remove_request(fsp->notify->requests); 366 } 367} 368 369void notify_fname(connection_struct *conn, uint32 action, uint32 filter, 370 const char *path) 371{ 372 char *fullpath; 373 char *parent; 374 const char *name; 375 376 if (path[0] == '.' && path[1] == '/') { 377 path += 2; 378 } 379 if (parent_dirname(talloc_tos(), path, &parent, &name)) { 380 struct smb_filename smb_fname_parent; 381 382 ZERO_STRUCT(smb_fname_parent); 383 smb_fname_parent.base_name = parent; 384 385 if (SMB_VFS_STAT(conn, &smb_fname_parent) != -1) { 386 notify_onelevel(conn->notify_ctx, action, filter, 387 SMB_VFS_FILE_ID_CREATE(conn, &smb_fname_parent.st), 388 name); 389 } 390 } 391 392 fullpath = talloc_asprintf(talloc_tos(), "%s/%s", conn->connectpath, 393 path); 394 if (fullpath == NULL) { 395 DEBUG(0, ("asprintf failed\n")); 396 return; 397 } 398 notify_trigger(conn->notify_ctx, action, filter, fullpath); 399 TALLOC_FREE(fullpath); 400} 401 402static void notify_fsp(files_struct *fsp, uint32 action, const char *name) 403{ 404 struct notify_change *change, *changes; 405 char *tmp; 406 407 if (fsp->notify == NULL) { 408 /* 409 * Nobody is waiting, don't queue 410 */ 411 return; 412 } 413 414 /* 415 * Someone has triggered a notify previously, queue the change for 416 * later. 417 */ 418 419 if ((fsp->notify->num_changes > 1000) || (name == NULL)) { 420 /* 421 * The real number depends on the client buf, just provide a 422 * guard against a DoS here. If name == NULL the CN backend is 423 * alerting us to a problem. Possibly dropped events. Clear 424 * queued changes and send the catch-all response to the client 425 * if a request is pending. 426 */ 427 TALLOC_FREE(fsp->notify->changes); 428 fsp->notify->num_changes = -1; 429 if (fsp->notify->requests != NULL) { 430 change_notify_reply(fsp->conn, 431 fsp->notify->requests->req, 432 NT_STATUS_OK, 433 fsp->notify->requests->max_param, 434 fsp->notify, 435 fsp->notify->requests->reply_fn); 436 change_notify_remove_request(fsp->notify->requests); 437 } 438 return; 439 } 440 441 /* If we've exceeded the server side queue or received a NULL name 442 * from the underlying CN implementation, don't queue up any more 443 * requests until we can send a catch-all response to the client */ 444 if (fsp->notify->num_changes == -1) { 445 return; 446 } 447 448 if (!(changes = TALLOC_REALLOC_ARRAY( 449 fsp->notify, fsp->notify->changes, 450 struct notify_change, fsp->notify->num_changes+1))) { 451 DEBUG(0, ("talloc_realloc failed\n")); 452 return; 453 } 454 455 fsp->notify->changes = changes; 456 457 change = &(fsp->notify->changes[fsp->notify->num_changes]); 458 459 if (!(tmp = talloc_strdup(changes, name))) { 460 DEBUG(0, ("talloc_strdup failed\n")); 461 return; 462 } 463 464 string_replace(tmp, '/', '\\'); 465 change->name = tmp; 466 467 change->action = action; 468 fsp->notify->num_changes += 1; 469 470 if (fsp->notify->requests == NULL) { 471 /* 472 * Nobody is waiting, so don't send anything. The ot 473 */ 474 return; 475 } 476 477 if (action == NOTIFY_ACTION_OLD_NAME) { 478 /* 479 * We have to send the two rename events in one reply. So hold 480 * the first part back. 481 */ 482 return; 483 } 484 485 /* 486 * Someone is waiting for the change, trigger the reply immediately. 487 * 488 * TODO: do we have to walk the lists of requests pending? 489 */ 490 491 change_notify_reply(fsp->conn, 492 fsp->notify->requests->req, 493 NT_STATUS_OK, 494 fsp->notify->requests->max_param, 495 fsp->notify, 496 fsp->notify->requests->reply_fn); 497 498 change_notify_remove_request(fsp->notify->requests); 499} 500 501char *notify_filter_string(TALLOC_CTX *mem_ctx, uint32 filter) 502{ 503 char *result = NULL; 504 505 result = talloc_strdup(mem_ctx, ""); 506 507 if (filter & FILE_NOTIFY_CHANGE_FILE_NAME) 508 result = talloc_asprintf_append(result, "FILE_NAME|"); 509 if (filter & FILE_NOTIFY_CHANGE_DIR_NAME) 510 result = talloc_asprintf_append(result, "DIR_NAME|"); 511 if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES) 512 result = talloc_asprintf_append(result, "ATTRIBUTES|"); 513 if (filter & FILE_NOTIFY_CHANGE_SIZE) 514 result = talloc_asprintf_append(result, "SIZE|"); 515 if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE) 516 result = talloc_asprintf_append(result, "LAST_WRITE|"); 517 if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS) 518 result = talloc_asprintf_append(result, "LAST_ACCESS|"); 519 if (filter & FILE_NOTIFY_CHANGE_CREATION) 520 result = talloc_asprintf_append(result, "CREATION|"); 521 if (filter & FILE_NOTIFY_CHANGE_EA) 522 result = talloc_asprintf_append(result, "EA|"); 523 if (filter & FILE_NOTIFY_CHANGE_SECURITY) 524 result = talloc_asprintf_append(result, "SECURITY|"); 525 if (filter & FILE_NOTIFY_CHANGE_STREAM_NAME) 526 result = talloc_asprintf_append(result, "STREAM_NAME|"); 527 if (filter & FILE_NOTIFY_CHANGE_STREAM_SIZE) 528 result = talloc_asprintf_append(result, "STREAM_SIZE|"); 529 if (filter & FILE_NOTIFY_CHANGE_STREAM_WRITE) 530 result = talloc_asprintf_append(result, "STREAM_WRITE|"); 531 532 if (result == NULL) return NULL; 533 if (*result == '\0') return result; 534 535 result[strlen(result)-1] = '\0'; 536 return result; 537} 538 539struct sys_notify_context *sys_notify_context_create(connection_struct *conn, 540 TALLOC_CTX *mem_ctx, 541 struct event_context *ev) 542{ 543 struct sys_notify_context *ctx; 544 545 if (!(ctx = TALLOC_P(mem_ctx, struct sys_notify_context))) { 546 DEBUG(0, ("talloc failed\n")); 547 return NULL; 548 } 549 550 ctx->ev = ev; 551 ctx->conn = conn; 552 ctx->private_data = NULL; 553 return ctx; 554} 555 556NTSTATUS sys_notify_watch(struct sys_notify_context *ctx, 557 struct notify_entry *e, 558 void (*callback)(struct sys_notify_context *ctx, 559 void *private_data, 560 struct notify_event *ev), 561 void *private_data, void *handle) 562{ 563 return SMB_VFS_NOTIFY_WATCH(ctx->conn, ctx, e, callback, private_data, 564 handle); 565} 566 567