/* Unix SMB/CIFS implementation. change notify handling Copyright (C) Andrew Tridgell 2000 Copyright (C) Jeremy Allison 1994-1998 Copyright (C) Volker Lendecke 2007 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "includes.h" #include "smbd/globals.h" struct notify_change_request { struct notify_change_request *prev, *next; struct files_struct *fsp; /* backpointer for cancel by mid */ struct smb_request *req; uint32 filter; uint32 max_param; struct notify_mid_map *mid_map; void *backend_data; }; static void notify_fsp(files_struct *fsp, uint32 action, const char *name); /* * For NTCancel, we need to find the notify_change_request indexed by * mid. Separate list here. */ struct notify_mid_map { struct notify_mid_map *prev, *next; struct notify_change_request *req; uint16 mid; }; static bool notify_change_record_identical(struct notify_change *c1, struct notify_change *c2) { /* Note this is deliberately case sensitive. */ if (c1->action == c2->action && strcmp(c1->name, c2->name) == 0) { return True; } return False; } static bool notify_marshall_changes(int num_changes, uint32 max_offset, struct notify_change *changes, prs_struct *ps) { int i; UNISTR uni_name; uni_name.buffer = NULL; for (i=0; i<num_changes; i++) { struct notify_change *c; size_t namelen; uint32 u32_tmp; /* Temp arg to prs_uint32 to avoid * signed/unsigned issues */ /* Coalesce any identical records. */ while (i+1 < num_changes && notify_change_record_identical(&changes[i], &changes[i+1])) { i++; } c = &changes[i]; if (!convert_string_allocate(NULL, CH_UNIX, CH_UTF16LE, c->name, strlen(c->name)+1, &uni_name.buffer, &namelen, True) || (uni_name.buffer == NULL)) { goto fail; } namelen -= 2; /* Dump NULL termination */ /* * Offset to next entry, only if there is one */ u32_tmp = (i == num_changes-1) ? 0 : namelen + 12; if (!prs_uint32("offset", ps, 1, &u32_tmp)) goto fail; u32_tmp = c->action; if (!prs_uint32("action", ps, 1, &u32_tmp)) goto fail; u32_tmp = namelen; if (!prs_uint32("namelen", ps, 1, &u32_tmp)) goto fail; if (!prs_unistr("name", ps, 1, &uni_name)) goto fail; /* * Not NULL terminated, decrease by the 2 UCS2 \0 chars */ prs_set_offset(ps, prs_offset(ps)-2); SAFE_FREE(uni_name.buffer); if (prs_offset(ps) > max_offset) { /* Too much data for client. */ DEBUG(10, ("Client only wanted %d bytes, trying to " "marshall %d bytes\n", (int)max_offset, (int)prs_offset(ps))); return False; } } return True; fail: SAFE_FREE(uni_name.buffer); return False; } /**************************************************************************** Setup the common parts of the return packet and send it. *****************************************************************************/ static void change_notify_reply_packet(connection_struct *conn, struct smb_request *req, NTSTATUS error_code) { reply_outbuf(req, 18, 0); if (!NT_STATUS_IS_OK(error_code)) { error_packet_set((char *)req->outbuf, 0, 0, error_code, __LINE__,__FILE__); } show_msg((char *)req->outbuf); if (!srv_send_smb(smbd_server_fd(), (char *)req->outbuf, req->encrypted, &req->pcd)) { exit_server_cleanly("change_notify_reply_packet: srv_send_smb " "failed."); } TALLOC_FREE(req->outbuf); } void change_notify_reply(connection_struct *conn, struct smb_request *req, uint32 max_param, struct notify_change_buf *notify_buf) { prs_struct ps; if (notify_buf->num_changes == -1) { change_notify_reply_packet(conn, req, NT_STATUS_OK); notify_buf->num_changes = 0; return; } prs_init_empty(&ps, NULL, MARSHALL); if (!notify_marshall_changes(notify_buf->num_changes, max_param, notify_buf->changes, &ps)) { /* * We exceed what the client is willing to accept. Send * nothing. */ change_notify_reply_packet(conn, req, NT_STATUS_OK); goto done; } send_nt_replies(conn, req, NT_STATUS_OK, prs_data_p(&ps), prs_offset(&ps), NULL, 0); done: prs_mem_free(&ps); TALLOC_FREE(notify_buf->changes); notify_buf->num_changes = 0; } static void notify_callback(void *private_data, const struct notify_event *e) { files_struct *fsp = (files_struct *)private_data; DEBUG(10, ("notify_callback called for %s\n", fsp->fsp_name)); notify_fsp(fsp, e->action, e->path); } NTSTATUS change_notify_create(struct files_struct *fsp, uint32 filter, bool recursive) { char *fullpath; struct notify_entry e; NTSTATUS status; SMB_ASSERT(fsp->notify == NULL); if (!(fsp->notify = TALLOC_ZERO_P(NULL, struct notify_change_buf))) { DEBUG(0, ("talloc failed\n")); return NT_STATUS_NO_MEMORY; } if (asprintf(&fullpath, "%s/%s", fsp->conn->connectpath, fsp->fsp_name) == -1) { DEBUG(0, ("asprintf failed\n")); return NT_STATUS_NO_MEMORY; } ZERO_STRUCT(e); e.path = fullpath; e.dir_fd = fsp->fh->fd; e.dir_id = fsp->file_id; e.filter = filter; e.subdir_filter = 0; if (recursive) { e.subdir_filter = filter; } status = notify_add(fsp->conn->notify_ctx, &e, notify_callback, fsp); SAFE_FREE(fullpath); return status; } NTSTATUS change_notify_add_request(struct smb_request *req, uint32 max_param, uint32 filter, bool recursive, struct files_struct *fsp) { struct notify_change_request *request = NULL; struct notify_mid_map *map = NULL; DEBUG(10, ("change_notify_add_request: Adding request for %s: " "max_param = %d\n", fsp->fsp_name, (int)max_param)); if (!(request = talloc(NULL, struct notify_change_request)) || !(map = talloc(request, struct notify_mid_map))) { TALLOC_FREE(request); return NT_STATUS_NO_MEMORY; } request->mid_map = map; map->req = request; request->req = talloc_move(request, &req); request->max_param = max_param; request->filter = filter; request->fsp = fsp; request->backend_data = NULL; DLIST_ADD_END(fsp->notify->requests, request, struct notify_change_request *); map->mid = request->req->mid; DLIST_ADD(notify_changes_by_mid, map); /* Push the MID of this packet on the signing queue. */ srv_defer_sign_response(request->req->mid); return NT_STATUS_OK; } static void change_notify_remove_request(struct notify_change_request *remove_req) { files_struct *fsp; struct notify_change_request *req; /* * Paranoia checks, the fsp referenced must must have the request in * its list of pending requests */ fsp = remove_req->fsp; SMB_ASSERT(fsp->notify != NULL); for (req = fsp->notify->requests; req; req = req->next) { if (req == remove_req) { break; } } if (req == NULL) { smb_panic("notify_req not found in fsp's requests"); } DLIST_REMOVE(fsp->notify->requests, req); DLIST_REMOVE(notify_changes_by_mid, req->mid_map); TALLOC_FREE(req); } /**************************************************************************** Delete entries by mid from the change notify pending queue. Always send reply. *****************************************************************************/ void remove_pending_change_notify_requests_by_mid(uint16 mid) { struct notify_mid_map *map; for (map = notify_changes_by_mid; map; map = map->next) { if (map->mid == mid) { break; } } if (map == NULL) { return; } change_notify_reply_packet(map->req->fsp->conn, map->req->req, NT_STATUS_CANCELLED); change_notify_remove_request(map->req); } /**************************************************************************** Delete entries by fnum from the change notify pending queue. *****************************************************************************/ void remove_pending_change_notify_requests_by_fid(files_struct *fsp, NTSTATUS status) { if (fsp->notify == NULL) { return; } while (fsp->notify->requests != NULL) { change_notify_reply_packet( fsp->conn, fsp->notify->requests->req, status); change_notify_remove_request(fsp->notify->requests); } } void notify_fname(connection_struct *conn, uint32 action, uint32 filter, const char *path) { char *fullpath; if (path[0] == '.' && path[1] == '/') { path += 2; } if (asprintf(&fullpath, "%s/%s", conn->connectpath, path) == -1) { DEBUG(0, ("asprintf failed\n")); return; } notify_trigger(conn->notify_ctx, action, filter, fullpath); SAFE_FREE(fullpath); } static void notify_fsp(files_struct *fsp, uint32 action, const char *name) { struct notify_change *change, *changes; char *tmp; if (fsp->notify == NULL) { /* * Nobody is waiting, don't queue */ return; } /* * Someone has triggered a notify previously, queue the change for * later. */ if ((fsp->notify->num_changes > 1000) || (name == NULL)) { /* * The real number depends on the client buf, just provide a * guard against a DoS here. If name == NULL the CN backend is * alerting us to a problem. Possibly dropped events. Clear * queued changes and send the catch-all response to the client * if a request is pending. */ TALLOC_FREE(fsp->notify->changes); fsp->notify->num_changes = -1; if (fsp->notify->requests != NULL) { change_notify_reply(fsp->conn, fsp->notify->requests->req, fsp->notify->requests->max_param, fsp->notify); change_notify_remove_request(fsp->notify->requests); } return; } /* If we've exceeded the server side queue or received a NULL name * from the underlying CN implementation, don't queue up any more * requests until we can send a catch-all response to the client */ if (fsp->notify->num_changes == -1) { return; } if (!(changes = TALLOC_REALLOC_ARRAY( fsp->notify, fsp->notify->changes, struct notify_change, fsp->notify->num_changes+1))) { DEBUG(0, ("talloc_realloc failed\n")); return; } fsp->notify->changes = changes; change = &(fsp->notify->changes[fsp->notify->num_changes]); if (!(tmp = talloc_strdup(changes, name))) { DEBUG(0, ("talloc_strdup failed\n")); return; } string_replace(tmp, '/', '\\'); change->name = tmp; change->action = action; fsp->notify->num_changes += 1; if (fsp->notify->requests == NULL) { /* * Nobody is waiting, so don't send anything. The ot */ return; } if (action == NOTIFY_ACTION_OLD_NAME) { /* * We have to send the two rename events in one reply. So hold * the first part back. */ return; } /* * Someone is waiting for the change, trigger the reply immediately. * * TODO: do we have to walk the lists of requests pending? */ change_notify_reply(fsp->conn, fsp->notify->requests->req, fsp->notify->requests->max_param, fsp->notify); change_notify_remove_request(fsp->notify->requests); } char *notify_filter_string(TALLOC_CTX *mem_ctx, uint32 filter) { char *result = NULL; result = talloc_strdup(mem_ctx, ""); if (filter & FILE_NOTIFY_CHANGE_FILE_NAME) result = talloc_asprintf_append(result, "FILE_NAME|"); if (filter & FILE_NOTIFY_CHANGE_DIR_NAME) result = talloc_asprintf_append(result, "DIR_NAME|"); if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES) result = talloc_asprintf_append(result, "ATTRIBUTES|"); if (filter & FILE_NOTIFY_CHANGE_SIZE) result = talloc_asprintf_append(result, "SIZE|"); if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE) result = talloc_asprintf_append(result, "LAST_WRITE|"); if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS) result = talloc_asprintf_append(result, "LAST_ACCESS|"); if (filter & FILE_NOTIFY_CHANGE_CREATION) result = talloc_asprintf_append(result, "CREATION|"); if (filter & FILE_NOTIFY_CHANGE_EA) result = talloc_asprintf_append(result, "EA|"); if (filter & FILE_NOTIFY_CHANGE_SECURITY) result = talloc_asprintf_append(result, "SECURITY|"); if (filter & FILE_NOTIFY_CHANGE_STREAM_NAME) result = talloc_asprintf_append(result, "STREAM_NAME|"); if (filter & FILE_NOTIFY_CHANGE_STREAM_SIZE) result = talloc_asprintf_append(result, "STREAM_SIZE|"); if (filter & FILE_NOTIFY_CHANGE_STREAM_WRITE) result = talloc_asprintf_append(result, "STREAM_WRITE|"); if (result == NULL) return NULL; if (*result == '\0') return result; result[strlen(result)-1] = '\0'; return result; } struct sys_notify_context *sys_notify_context_create(connection_struct *conn, TALLOC_CTX *mem_ctx, struct event_context *ev) { struct sys_notify_context *ctx; if (!(ctx = TALLOC_P(mem_ctx, struct sys_notify_context))) { DEBUG(0, ("talloc failed\n")); return NULL; } ctx->ev = ev; ctx->conn = conn; ctx->private_data = NULL; return ctx; } NTSTATUS sys_notify_watch(struct sys_notify_context *ctx, struct notify_entry *e, void (*callback)(struct sys_notify_context *ctx, void *private_data, struct notify_event *ev), void *private_data, void *handle) { return SMB_VFS_NOTIFY_WATCH(ctx->conn, ctx, e, callback, private_data, handle); }