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 #ifdef HAVE_STAT_HIRES_TIMESTAMPS
27 struct timespec modify_time;
28 struct timespec status_time;
30 time_t modify_time; /* Info from the directory we're monitoring. */
31 time_t status_time; /* Info from the directory we're monitoring. */
33 time_t total_time; /* Total time of all directory entries - don't care if it wraps. */
34 unsigned int num_entries; /* Zero or the number of files in the directory. */
35 unsigned int mode_sum;
36 unsigned char name_hash[16];
40 #ifdef HAVE_STAT_HIRES_TIMESTAMPS
41 /* Compare struct timespec. */
42 #define TIMESTAMP_NEQ(x, y) (((x).tv_sec != (y).tv_sec) || ((x).tv_nsec != (y).tv_nsec))
44 /* Compare time_t . */
45 #define TIMESTAMP_NEQ(x, y) ((x) != (y))
48 /****************************************************************************
49 Create the hash we will use to determine if the contents changed.
50 *****************************************************************************/
52 static BOOL notify_hash(connection_struct *conn, char *path, uint32 flags,
53 struct change_data *data, struct change_data *old_data)
66 if(SMB_VFS_STAT(conn,path, &st) == -1)
69 #ifdef HAVE_STAT_HIRES_TIMESTAMPS
70 data->modify_time = st.st_mtim;
71 data->status_time = st.st_ctim;
73 data->modify_time = st.st_mtime;
74 data->status_time = st.st_ctime;
79 * Shortcut to avoid directory scan if the time
80 * has changed - we always must return true then.
82 if (TIMESTAMP_NEQ(old_data->modify_time, data->modify_time) ||
83 TIMESTAMP_NEQ(old_data->status_time, data->status_time) ) {
88 if (S_ISDIR(st.st_mode) &&
89 (flags & ~(FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME)) == 0)
91 /* This is the case of a client wanting to know only when
92 * the contents of a directory changes. Since any file
93 * creation, rename or deletion will update the directory
94 * timestamps, we don't need to create a hash.
100 * If we are to watch for changes that are only stored
101 * in inodes of files, not in the directory inode, we must
102 * scan the directory and produce a unique identifier with
103 * which we can determine if anything changed. We use the
104 * modify and change times from all the files in the
105 * directory, added together (ignoring wrapping if it's
106 * larger than the max time_t value).
109 dp = OpenDir(conn, path, NULL, 0);
113 data->num_entries = 0;
115 pstrcpy(full_name, path);
116 pstrcat(full_name, "/");
118 fullname_len = strlen(full_name);
119 remaining_len = sizeof(full_name) - fullname_len - 1;
120 p = &full_name[fullname_len];
123 while ((fname = ReadDirName(dp, &offset))) {
124 SET_STAT_INVALID(st);
125 if(strequal(fname, ".") || strequal(fname, ".."))
128 if (!is_visible_file(conn, path, fname, &st, True))
132 safe_strcpy(p, fname, remaining_len);
135 * Do the stat - but ignore errors.
137 if (!VALID_STAT(st)) {
138 SMB_VFS_STAT(conn,full_name, &st);
142 * Always sum the times.
145 data->total_time += (st.st_mtime + st.st_ctime);
148 * If requested hash the names.
151 if (flags & (FILE_NOTIFY_CHANGE_DIR_NAME|FILE_NOTIFY_CHANGE_FILE_NAME|FILE_NOTIFY_CHANGE_FILE)) {
153 unsigned char tmp_hash[16];
154 mdfour(tmp_hash, (const unsigned char *)fname, strlen(fname));
156 data->name_hash[i] ^= tmp_hash[i];
160 * If requested sum the mode_t's.
163 if (flags & (FILE_NOTIFY_CHANGE_ATTRIBUTES|FILE_NOTIFY_CHANGE_SECURITY))
164 data->mode_sum += st.st_mode;
172 /****************************************************************************
173 Register a change notify request.
174 *****************************************************************************/
176 static void *hash_register_notify(connection_struct *conn, char *path, uint32 flags)
178 struct change_data data;
180 if (!notify_hash(conn, path, flags, &data, NULL))
183 data.last_check_time = time(NULL);
185 return (void *)memdup(&data, sizeof(data));
188 /****************************************************************************
189 Check if a change notify should be issued.
190 A time of zero means instantaneous check - don't modify the last check time.
191 *****************************************************************************/
193 static BOOL hash_check_notify(connection_struct *conn, uint16 vuid, char *path, uint32 flags, void *datap, time_t t)
195 struct change_data *data = (struct change_data *)datap;
196 struct change_data data2;
198 if (t && t < data->last_check_time + lp_change_notify_timeout())
201 if (!change_to_user(conn,vuid))
203 if (!set_current_service(conn,FLAG_CASELESS_PATHNAMES,True)) {
204 change_to_root_user();
208 if (!notify_hash(conn, path, flags, &data2, data) ||
209 TIMESTAMP_NEQ(data2.modify_time, data->modify_time) ||
210 TIMESTAMP_NEQ(data2.status_time, data->status_time) ||
211 data2.total_time != data->total_time ||
212 data2.num_entries != data->num_entries ||
213 data2.mode_sum != data->mode_sum ||
214 memcmp(data2.name_hash, data->name_hash, sizeof(data2.name_hash))) {
215 change_to_root_user();
220 data->last_check_time = t;
222 change_to_root_user();
227 /****************************************************************************
228 Remove a change notify data structure.
229 *****************************************************************************/
231 static void hash_remove_notify(void *datap)
236 /****************************************************************************
237 Setup hash based change notify.
238 ****************************************************************************/
240 struct cnotify_fns *hash_notify_init(void)
242 static struct cnotify_fns cnotify;
244 cnotify.register_notify = hash_register_notify;
245 cnotify.check_notify = hash_check_notify;
246 cnotify.remove_notify = hash_remove_notify;
247 cnotify.select_time = lp_change_notify_timeout();
253 change_notify_reply_packet(cnbp->request_buf,ERRSRV,ERRaccess);
254 change_notify_reply_packet(cnbp->request_buf,0,NT_STATUS_NOTIFY_ENUM_DIR);
259 uint16 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
260 SVAL(cnbp->request_buf,smb_uid);