/* Unix SMB/Netbios implementation. Version 3.0 change notify handling - hash based implementation Copyright (C) Jeremy Allison 1994-1998 Copyright (C) Andrew Tridgell 2000 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 2 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, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "includes.h" struct change_data { time_t last_check_time; /* time we last checked this entry */ time_t modify_time; /* Info from the directory we're monitoring. */ time_t status_time; /* Info from the directory we're monitoring. */ time_t total_time; /* Total time of all directory entries - don't care if it wraps. */ unsigned int num_entries; /* Zero or the number of files in the directory. */ unsigned int mode_sum; unsigned char name_hash[16]; }; /**************************************************************************** Create the hash we will use to determine if the contents changed. *****************************************************************************/ static BOOL notify_hash(connection_struct *conn, char *path, uint32 flags, struct change_data *data, struct change_data *old_data) { SMB_STRUCT_STAT st; pstring full_name; char *p; char *fname; size_t remaining_len; size_t fullname_len; void *dp; ZERO_STRUCTP(data); if(vfs_stat(conn,path, &st) == -1) return False; data->modify_time = st.st_mtime; data->status_time = st.st_ctime; if (old_data) { /* * Shortcut to avoid directory scan if the time * has changed - we always must return true then. */ if (old_data->modify_time != data->modify_time || old_data->status_time != data->status_time ) { return True; } } /* * If we are to watch for changes that are only stored * in inodes of files, not in the directory inode, we must * scan the directory and produce a unique identifier with * which we can determine if anything changed. We use the * modify and change times from all the files in the * directory, added together (ignoring wrapping if it's * larger than the max time_t value). */ dp = OpenDir(conn, path, True); if (dp == NULL) return False; data->num_entries = 0; pstrcpy(full_name, path); pstrcat(full_name, "/"); fullname_len = strlen(full_name); remaining_len = sizeof(full_name) - fullname_len - 1; p = &full_name[fullname_len]; while ((fname = ReadDirName(dp))) { if(strequal(fname, ".") || strequal(fname, "..")) continue; data->num_entries++; safe_strcpy(p, fname, remaining_len); ZERO_STRUCT(st); /* * Do the stat - but ignore errors. */ vfs_stat(conn,full_name, &st); /* * Always sum the times. */ data->total_time += (st.st_mtime + st.st_ctime); /* * If requested hash the names. */ if (flags & (FILE_NOTIFY_CHANGE_DIR_NAME|FILE_NOTIFY_CHANGE_FILE_NAME|FILE_NOTIFY_CHANGE_FILE)) { int i; unsigned char tmp_hash[16]; mdfour(tmp_hash, (unsigned char *)fname, strlen(fname)); for (i=0;i<16;i++) data->name_hash[i] ^= tmp_hash[i]; } /* * If requested sum the mode_t's. */ if (flags & (FILE_NOTIFY_CHANGE_ATTRIBUTES|FILE_NOTIFY_CHANGE_SECURITY)) data->mode_sum = st.st_mode; } CloseDir(dp); return True; } /**************************************************************************** Register a change notify request. *****************************************************************************/ static void *hash_register_notify(connection_struct *conn, char *path, uint32 flags) { struct change_data data; if (!notify_hash(conn, path, flags, &data, NULL)) return NULL; data.last_check_time = time(NULL); return (void *)memdup(&data, sizeof(data)); } /**************************************************************************** Check if a change notify should be issued. A time of zero means instantaneous check - don't modify the last check time. *****************************************************************************/ static BOOL hash_check_notify(connection_struct *conn, uint16 vuid, char *path, uint32 flags, void *datap, time_t t) { struct change_data *data = (struct change_data *)datap; struct change_data data2; if (t && t < data->last_check_time + lp_change_notify_timeout()) return False; if (!change_to_user(conn,vuid)) return True; if (!set_current_service(conn,True)) { change_to_root_user(); return True; } if (!notify_hash(conn, path, flags, &data2, data) || data2.modify_time != data->modify_time || data2.status_time != data->status_time || data2.total_time != data->total_time || data2.num_entries != data->num_entries || data2.mode_sum != data->mode_sum || memcmp(data2.name_hash, data->name_hash, sizeof(data2.name_hash))) { change_to_root_user(); return True; } if (t) data->last_check_time = t; change_to_root_user(); return False; } /**************************************************************************** Remove a change notify data structure. *****************************************************************************/ static void hash_remove_notify(void *datap) { SAFE_FREE(datap); } /**************************************************************************** Setup hash based change notify. ****************************************************************************/ struct cnotify_fns *hash_notify_init(void) { static struct cnotify_fns cnotify; cnotify.register_notify = hash_register_notify; cnotify.check_notify = hash_check_notify; cnotify.remove_notify = hash_remove_notify; cnotify.select_time = lp_change_notify_timeout(); return &cnotify; } /* change_notify_reply_packet(cnbp->request_buf,ERRSRV,ERRaccess); change_notify_reply_packet(cnbp->request_buf,0,NT_STATUS_NOTIFY_ENUM_DIR); chain_size = 0; file_chain_reset(); uint16 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID : SVAL(cnbp->request_buf,smb_uid); */