diff options
Diffstat (limited to 'source3/smbd/notify_hash.c')
| -rw-r--r-- | source3/smbd/notify_hash.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/source3/smbd/notify_hash.c b/source3/smbd/notify_hash.c new file mode 100644 index 0000000000..d8b35462ac --- /dev/null +++ b/source3/smbd/notify_hash.c @@ -0,0 +1,225 @@ +/* + 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 */ + 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) +{ + 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); +*/ |