2 Unix SMB/CIFS implementation.
3 change notify handling - hash based implementation
4 Copyright (C) Jeremy Allison 1994-1998
5 Copyright (C) Andrew Tridgell 2000
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 time_t last_check_time; /* time we last checked this entry */
26 time_t modify_time; /* Info from the directory we're monitoring. */
27 time_t status_time; /* Info from the directory we're monitoring. */
28 time_t total_time; /* Total time of all directory entries - don't care if it wraps. */
29 unsigned int num_entries; /* Zero or the number of files in the directory. */
30 unsigned int mode_sum;
31 unsigned char name_hash[16];
34 /****************************************************************************
35 Create the hash we will use to determine if the contents changed.
36 *****************************************************************************/
38 static BOOL notify_hash(connection_struct *conn, char *path, uint32 flags,
39 struct change_data *data, struct change_data *old_data)
52 if(SMB_VFS_STAT(conn,path, &st) == -1)
55 data->modify_time = st.st_mtime;
56 data->status_time = st.st_ctime;
60 * Shortcut to avoid directory scan if the time
61 * has changed - we always must return true then.
63 if (old_data->modify_time != data->modify_time ||
64 old_data->status_time != data->status_time ) {
70 * If we are to watch for changes that are only stored
71 * in inodes of files, not in the directory inode, we must
72 * scan the directory and produce a unique identifier with
73 * which we can determine if anything changed. We use the
74 * modify and change times from all the files in the
75 * directory, added together (ignoring wrapping if it's
76 * larger than the max time_t value).
79 dp = OpenDir(conn, path);
83 data->num_entries = 0;
85 pstrcpy(full_name, path);
86 pstrcat(full_name, "/");
88 fullname_len = strlen(full_name);
89 remaining_len = sizeof(full_name) - fullname_len - 1;
90 p = &full_name[fullname_len];
93 while ((fname = ReadDirName(dp, &offset))) {
95 if(strequal(fname, ".") || strequal(fname, ".."))
98 if (!is_visible_file(conn, path, fname, &st, True))
102 safe_strcpy(p, fname, remaining_len);
105 * Do the stat - but ignore errors.
107 if (!VALID_STAT(st)) {
108 SMB_VFS_STAT(conn,full_name, &st);
112 * Always sum the times.
115 data->total_time += (st.st_mtime + st.st_ctime);
118 * If requested hash the names.
121 if (flags & (FILE_NOTIFY_CHANGE_DIR_NAME|FILE_NOTIFY_CHANGE_FILE_NAME|FILE_NOTIFY_CHANGE_FILE)) {
123 unsigned char tmp_hash[16];
124 mdfour(tmp_hash, (const unsigned char *)fname, strlen(fname));
126 data->name_hash[i] ^= tmp_hash[i];
130 * If requested sum the mode_t's.
133 if (flags & (FILE_NOTIFY_CHANGE_ATTRIBUTES|FILE_NOTIFY_CHANGE_SECURITY))
134 data->mode_sum += st.st_mode;
142 /****************************************************************************
143 Register a change notify request.
144 *****************************************************************************/
146 static void *hash_register_notify(connection_struct *conn, char *path, uint32 flags)
148 struct change_data data;
150 if (!notify_hash(conn, path, flags, &data, NULL))
153 data.last_check_time = time(NULL);
155 return (void *)memdup(&data, sizeof(data));
158 /****************************************************************************
159 Check if a change notify should be issued.
160 A time of zero means instantaneous check - don't modify the last check time.
161 *****************************************************************************/
163 static BOOL hash_check_notify(connection_struct *conn, uint16 vuid, char *path, uint32 flags, void *datap, time_t t)
165 struct change_data *data = (struct change_data *)datap;
166 struct change_data data2;
168 if (t && t < data->last_check_time + lp_change_notify_timeout())
171 if (!change_to_user(conn,vuid))
173 if (!set_current_service(conn,FLAG_CASELESS_PATHNAMES,True)) {
174 change_to_root_user();
178 if (!notify_hash(conn, path, flags, &data2, data) ||
179 data2.modify_time != data->modify_time ||
180 data2.status_time != data->status_time ||
181 data2.total_time != data->total_time ||
182 data2.num_entries != data->num_entries ||
183 data2.mode_sum != data->mode_sum ||
184 memcmp(data2.name_hash, data->name_hash, sizeof(data2.name_hash))) {
185 change_to_root_user();
190 data->last_check_time = t;
192 change_to_root_user();
197 /****************************************************************************
198 Remove a change notify data structure.
199 *****************************************************************************/
201 static void hash_remove_notify(void *datap)
206 /****************************************************************************
207 Setup hash based change notify.
208 ****************************************************************************/
210 struct cnotify_fns *hash_notify_init(void)
212 static struct cnotify_fns cnotify;
214 cnotify.register_notify = hash_register_notify;
215 cnotify.check_notify = hash_check_notify;
216 cnotify.remove_notify = hash_remove_notify;
217 cnotify.select_time = lp_change_notify_timeout();
223 change_notify_reply_packet(cnbp->request_buf,ERRSRV,ERRaccess);
224 change_notify_reply_packet(cnbp->request_buf,0,NT_STATUS_NOTIFY_ENUM_DIR);
229 uint16 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
230 SVAL(cnbp->request_buf,smb_uid);