source/smbd/notify.c

   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 2 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, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24
  25 static struct notify_mid_map *notify_changes_by_mid;
  26
  27 /*
  28  * For NTCancel, we need to find the notify_change_request indexed by
  29  * mid. Separate list here.
  30  */
  31
  32 struct notify_mid_map {
  33         struct notify_mid_map *prev, *next;
  34         struct notify_change_request *req;
  35         uint16 mid;
  36 };
  37
  38 static BOOL notify_marshall_changes(int num_changes,
  39                                     struct notify_change *changes,
  40                                     prs_struct *ps)
  41 {
  42         int i;
  43         UNISTR uni_name;
  44
  45         for (i=0; i<num_changes; i++) {
  46                 struct notify_change *c = &changes[i];
  47                 size_t namelen;
  48                 uint32 u32_tmp; /* Temp arg to prs_uint32 to avoid
  49                                  * signed/unsigned issues */
  50
  51                 namelen = convert_string_allocate(
  52                         NULL, CH_UNIX, CH_UTF16LE, c->name, strlen(c->name)+1,
  53                         &uni_name.buffer, True);
  54                 if ((namelen == -1) || (uni_name.buffer == NULL)) {
  55                         goto fail;
  56                 }
  57
  58                 namelen -= 2;   /* Dump NULL termination */
  59
  60                 /*
  61                  * Offset to next entry, only if there is one
  62                  */
  63
  64                 u32_tmp = (i == num_changes-1) ? 0 : namelen + 12;
  65                 if (!prs_uint32("offset", ps, 1, &u32_tmp)) goto fail;
  66
  67                 u32_tmp = c->action;
  68                 if (!prs_uint32("action", ps, 1, &u32_tmp)) goto fail;
  69
  70                 u32_tmp = namelen;
  71                 if (!prs_uint32("namelen", ps, 1, &u32_tmp)) goto fail;
  72
  73                 if (!prs_unistr("name", ps, 1, &uni_name)) goto fail;
  74
  75                 /*
  76                  * Not NULL terminated, decrease by the 2 UCS2 \0 chars
  77                  */
  78                 prs_set_offset(ps, prs_offset(ps)-2);
  79
  80                 SAFE_FREE(uni_name.buffer);
  81         }
  82
  83         return True;
  84
  85  fail:
  86         SAFE_FREE(uni_name.buffer);
  87         return False;
  88 }
  89
  90 /****************************************************************************
  91  Setup the common parts of the return packet and send it.
  92 *****************************************************************************/
  93
  94 static void change_notify_reply_packet(const char *request_buf,
  95                                        NTSTATUS error_code)
  96 {
  97         char outbuf[smb_size+38];
  98
  99         memset(outbuf, '\0', sizeof(outbuf));
 100         construct_reply_common(request_buf, outbuf);
 101
 102         ERROR_NT(error_code);
 103
 104         /*
 105          * Seems NT needs a transact command with an error code
 106          * in it. This is a longer packet than a simple error.
 107          */
 108         set_message(outbuf,18,0,False);
 109
 110         show_msg(outbuf);
 111         if (!send_smb(smbd_server_fd(),outbuf))
 112                 exit_server_cleanly("change_notify_reply_packet: send_smb "
 113                                     "failed.");
 114 }
 115
 116 void change_notify_reply(const char *request_buf, uint32 max_param_count,
 117                          int num_changes, struct notify_change *changes)
 118 {
 119         char *outbuf = NULL;
 120         prs_struct ps;
 121         size_t buflen = smb_size+38+max_param_count;
 122
 123         if (num_changes == -1) {
 124                 change_notify_reply_packet(request_buf, NT_STATUS_OK);
 125                 return;
 126         }
 127
 128         if (!prs_init(&ps, 0, NULL, False)
 129             || !notify_marshall_changes(num_changes, changes, &ps)) {
 130                 change_notify_reply_packet(request_buf, NT_STATUS_NO_MEMORY);
 131                 goto done;
 132         }
 133
 134         if (prs_offset(&ps) > max_param_count) {
 135                 /*
 136                  * We exceed what the client is willing to accept. Send
 137                  * nothing.
 138                  */
 139                 change_notify_reply_packet(request_buf, NT_STATUS_OK);
 140                 goto done;
 141         }
 142
 143         if (!(outbuf = SMB_MALLOC_ARRAY(char, buflen))) {
 144                 change_notify_reply_packet(request_buf, NT_STATUS_NO_MEMORY);
 145                 goto done;
 146         }
 147
 148         construct_reply_common(request_buf, outbuf);
 149
 150         if (send_nt_replies(outbuf, buflen, NT_STATUS_OK, prs_data_p(&ps),
 151                             prs_offset(&ps), NULL, 0) == -1) {
 152                 exit_server("change_notify_reply_packet: send_smb failed.");
 153         }
 154
 155  done:
 156         SAFE_FREE(outbuf);
 157         prs_mem_free(&ps);
 158 }
 159
 160 NTSTATUS change_notify_add_request(const char *inbuf, uint32 max_param_count,
 161                                    uint32 filter, BOOL recursive,
 162                                    struct files_struct *fsp)
 163 {
 164         struct notify_change_request *request = NULL;
 165         struct notify_mid_map *map = NULL;
 166
 167         if (!(request = SMB_MALLOC_P(struct notify_change_request))
 168             || !(map = SMB_MALLOC_P(struct notify_mid_map))) {
 169                 SAFE_FREE(request);
 170                 return NT_STATUS_NO_MEMORY;
 171         }
 172
 173         request->mid_map = map;
 174         map->req = request;
 175
 176         memcpy(request->request_buf, inbuf, sizeof(request->request_buf));
 177         request->max_param_count = max_param_count;
 178         request->filter = filter;
 179         request->fsp = fsp;
 180         request->backend_data = NULL;
 181
 182         DLIST_ADD_END(fsp->notify->requests, request,
 183                       struct notify_change_request *);
 184
 185         map->mid = SVAL(inbuf, smb_mid);
 186         DLIST_ADD(notify_changes_by_mid, map);
 187
 188         /* Push the MID of this packet on the signing queue. */
 189         srv_defer_sign_response(SVAL(inbuf,smb_mid));
 190
 191         return NT_STATUS_OK;
 192 }
 193
 194 static void change_notify_remove_request(struct notify_change_request *remove_req)
 195 {
 196         files_struct *fsp;
 197         struct notify_change_request *req;
 198
 199         /*
 200          * Paranoia checks, the fsp referenced must must have the request in
 201          * its list of pending requests
 202          */
 203
 204         fsp = remove_req->fsp;
 205         SMB_ASSERT(fsp->notify != NULL);
 206
 207         for (req = fsp->notify->requests; req; req = req->next) {
 208                 if (req == remove_req) {
 209                         break;
 210                 }
 211         }
 212
 213         if (req == NULL) {
 214                 smb_panic("notify_req not found in fsp's requests\n");
 215         }
 216
 217         DLIST_REMOVE(fsp->notify->requests, req);
 218         DLIST_REMOVE(notify_changes_by_mid, req->mid_map);
 219         SAFE_FREE(req->mid_map);
 220         TALLOC_FREE(req->backend_data);
 221         SAFE_FREE(req);
 222 }
 223
 224 /****************************************************************************
 225  Delete entries by mid from the change notify pending queue. Always send reply.
 226 *****************************************************************************/
 227
 228 void remove_pending_change_notify_requests_by_mid(uint16 mid)
 229 {
 230         struct notify_mid_map *map;
 231
 232         for (map = notify_changes_by_mid; map; map = map->next) {
 233                 if (map->mid == mid) {
 234                         break;
 235                 }
 236         }
 237
 238         if (map == NULL) {
 239                 return;
 240         }
 241
 242         change_notify_reply_packet(map->req->request_buf, NT_STATUS_CANCELLED);
 243         change_notify_remove_request(map->req);
 244 }
 245
 246 /****************************************************************************
 247  Delete entries by fnum from the change notify pending queue.
 248 *****************************************************************************/
 249
 250 void remove_pending_change_notify_requests_by_fid(files_struct *fsp,
 251                                                   NTSTATUS status)
 252 {
 253         if (fsp->notify == NULL) {
 254                 return;
 255         }
 256
 257         while (fsp->notify->requests != NULL) {
 258                 change_notify_reply_packet(
 259                         fsp->notify->requests->request_buf, status);
 260                 change_notify_remove_request(fsp->notify->requests);
 261         }
 262 }
 263
 264 void notify_fname(connection_struct *conn, uint32 action, uint32 filter,
 265                   const char *path)
 266 {
 267         char *fullpath;
 268
 269         if (asprintf(&fullpath, "%s/%s", conn->connectpath, path) == -1) {
 270                 DEBUG(0, ("asprintf failed\n"));
 271                 return;
 272         }
 273
 274         notify_trigger(conn->notify_ctx, action, filter, fullpath);
 275         SAFE_FREE(fullpath);
 276 }
 277
 278 void notify_fsp(files_struct *fsp, uint32 action, const char *name)
 279 {
 280         struct notify_change *change, *changes;
 281         char *name2;
 282
 283         if (fsp->notify == NULL) {
 284                 /*
 285                  * Nobody is waiting, don't queue
 286                  */
 287                 return;
 288         }
 289
 290         if (!(name2 = talloc_strdup(fsp->notify, name))) {
 291                 DEBUG(0, ("talloc_strdup failed\n"));
 292                         return;
 293                 }
 294
 295         string_replace(name2, '/', '\\');
 296
 297         /*
 298          * Someone has triggered a notify previously, queue the change for
 299          * later. TODO: Limit the number of changes queued, test how filters
 300          * apply here. Do we have to store them?
 301          */
 302
 303         if ((fsp->notify->num_changes > 30) || (name == NULL)) {
 304                 /*
 305                  * W2k3 seems to store at most 30 changes.
 306                  */
 307                 TALLOC_FREE(fsp->notify->changes);
 308                 TALLOC_FREE(name2);
 309                 fsp->notify->num_changes = -1;
 310                 return;
 311         }
 312
 313         if (fsp->notify->num_changes == -1) {
 314                 return;
 315         }
 316
 317         if (!(changes = TALLOC_REALLOC_ARRAY(
 318                       fsp->notify, fsp->notify->changes,
 319                       struct notify_change, fsp->notify->num_changes+1))) {
 320                 DEBUG(0, ("talloc_realloc failed\n"));
 321                 TALLOC_FREE(name2);
 322                 return;
 323         }
 324
 325         fsp->notify->changes = changes;
 326
 327         change = &(fsp->notify->changes[fsp->notify->num_changes]);
 328
 329         change->name = talloc_move(changes, &name2);
 330         change->action = action;
 331         fsp->notify->num_changes += 1;
 332
 333         if (fsp->notify->requests == NULL) {
 334                 /*
 335                  * Nobody is waiting, so don't send anything. The ot
 336                  */
 337                 return;
 338         }
 339
 340         if (action == NOTIFY_ACTION_OLD_NAME) {
 341                 /*
 342                  * We have to send the two rename events in one reply. So hold
 343                  * the first part back.
 344                  */
 345         return;
 346         }
 347
 348         /*
 349          * Someone is waiting for the change, trigger the reply immediately.
 350          *
 351          * TODO: do we have to walk the lists of requests pending?
 352          */
 353
 354         change_notify_reply(fsp->notify->requests->request_buf,
 355                             fsp->notify->requests->max_param_count,
 356                             fsp->notify->num_changes,
 357                             fsp->notify->changes);
 358
 359         change_notify_remove_request(fsp->notify->requests);
 360
 361         TALLOC_FREE(fsp->notify->changes);
 362         fsp->notify->num_changes = 0;
 363 }
 364
 365 char *notify_filter_string(TALLOC_CTX *mem_ctx, uint32 filter)
 366 {
 367         char *result = NULL;
 368
 369         result = talloc_strdup(mem_ctx, "");
 370
 371         if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 372                 result = talloc_asprintf_append(result, "FILE_NAME|");
 373         if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 374                 result = talloc_asprintf_append(result, "DIR_NAME|");
 375         if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 376                 result = talloc_asprintf_append(result, "ATTRIBUTES|");
 377         if (filter & FILE_NOTIFY_CHANGE_SIZE)
 378                 result = talloc_asprintf_append(result, "SIZE|");
 379         if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 380                 result = talloc_asprintf_append(result, "LAST_WRITE|");
 381         if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 382                 result = talloc_asprintf_append(result, "LAST_ACCESS|");
 383         if (filter & FILE_NOTIFY_CHANGE_CREATION)
 384                 result = talloc_asprintf_append(result, "CREATION|");
 385         if (filter & FILE_NOTIFY_CHANGE_EA)
 386                 result = talloc_asprintf_append(result, "EA|");
 387         if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 388                 result = talloc_asprintf_append(result, "SECURITY|");
 389         if (filter & FILE_NOTIFY_CHANGE_STREAM_NAME)
 390                 result = talloc_asprintf_append(result, "STREAM_NAME|");
 391         if (filter & FILE_NOTIFY_CHANGE_STREAM_SIZE)
 392                 result = talloc_asprintf_append(result, "STREAM_SIZE|");
 393         if (filter & FILE_NOTIFY_CHANGE_STREAM_WRITE)
 394                 result = talloc_asprintf_append(result, "STREAM_WRITE|");
 395
 396         if (result == NULL) return NULL;
 397         if (*result == '\0') return result;
 398
 399         result[strlen(result)-1] = '\0';
 400         return result;
 401 }
 402
 403 struct sys_notify_context *sys_notify_context_create(struct share_params *scfg,
 404                                                      TALLOC_CTX *mem_ctx,
 405                                                      struct event_context *ev)
 406 {
 407         struct sys_notify_context *ctx;
 408
 409         if (!(ctx = TALLOC_P(mem_ctx, struct sys_notify_context))) {
 410                 DEBUG(0, ("talloc failed\n"));
 411                 return NULL;
 412         }
 413
 414         ctx->ev = ev;
 415         ctx->private_data = NULL;
 416         return ctx;
 417 }
 418
 419 NTSTATUS sys_notify_watch(struct sys_notify_context *ctx,
 420                           struct notify_entry *e,
 421                           void (*callback)(struct sys_notify_context *ctx,
 422                                            void *private_data,
 423                                            struct notify_event *ev),
 424                           void *private_data, void *handle)
 425 {
 426 #ifdef HAVE_INOTIFY
 427         return inotify_watch(ctx, e, callback, private_data, handle);
 428 #else
 429         return NT_STATUS_OK;
 430 #endif
 431 }
 432