+/*
+ Unix SMB/CIFS implementation.
+ 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 */
+#ifdef HAVE_STAT_HIRES_TIMESTAMPS
+ struct timespec modify_time;
+ struct timespec status_time;
+#else
+ time_t modify_time; /* Info from the directory we're monitoring. */
+ time_t status_time; /* Info from the directory we're monitoring. */
+#endif
+ 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];
+};
+
+
+#ifdef HAVE_STAT_HIRES_TIMESTAMPS
+/* Compare struct timespec. */
+#define TIMESTAMP_NEQ(x, y) (((x).tv_sec != (y).tv_sec) || ((x).tv_nsec != (y).tv_nsec))
+#else
+/* Compare time_t . */
+#define TIMESTAMP_NEQ(x, y) ((x) != (y))
+#endif
+
+/****************************************************************************
+ 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;
+ const char *fname;
+ size_t remaining_len;
+ size_t fullname_len;
+ struct smb_Dir *dp;
+ long offset;
+
+ ZERO_STRUCTP(data);
+
+ if(SMB_VFS_STAT(conn,path, &st) == -1)
+ return False;
+
+#ifdef HAVE_STAT_HIRES_TIMESTAMPS
+ data->modify_time = st.st_mtim;
+ data->status_time = st.st_ctim;
+#else
+ data->modify_time = st.st_mtime;
+ data->status_time = st.st_ctime;
+#endif
+
+ if (old_data) {
+ /*
+ * Shortcut to avoid directory scan if the time
+ * has changed - we always must return true then.
+ */
+ if (TIMESTAMP_NEQ(old_data->modify_time, data->modify_time) ||
+ TIMESTAMP_NEQ(old_data->status_time, data->status_time) ) {
+ return True;
+ }
+ }
+
+ if (S_ISDIR(st.st_mode) &&
+ (flags & ~(FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME)) == 0)
+ {
+ /* This is the case of a client wanting to know only when
+ * the contents of a directory changes. Since any file
+ * creation, rename or deletion will update the directory
+ * timestamps, we don't need to create a hash.
+ */
+ 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, NULL, 0);
+ 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];
+
+ offset = 0;
+ while ((fname = ReadDirName(dp, &offset))) {
+ SET_STAT_INVALID(st);
+ if(strequal(fname, ".") || strequal(fname, ".."))
+ continue;
+
+ if (!is_visible_file(conn, path, fname, &st, True))
+ continue;
+
+ data->num_entries++;
+ safe_strcpy(p, fname, remaining_len);
+
+ /*
+ * Do the stat - but ignore errors.
+ */
+ if (!VALID_STAT(st)) {
+ SMB_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, (const 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,FLAG_CASELESS_PATHNAMES,True)) {
+ change_to_root_user();
+ return True;
+ }
+
+ if (!notify_hash(conn, path, flags, &data2, data) ||
+ TIMESTAMP_NEQ(data2.modify_time, data->modify_time) ||
+ TIMESTAMP_NEQ(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)
+{
+ 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);
+*/
projects / samba / blobdiff