source/smbd/notify.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 3.0
   4    change notify handling
   5    Copyright (C) Andrew Tridgell 2000
   6    Copyright (C) Jeremy Allison 1994-1998
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24
  25 static struct cnotify_fns *cnotify;
  26
  27 /****************************************************************************
  28  This is the structure to queue to implement NT change
  29  notify. It consists of smb_size bytes stored from the
  30  transact command (to keep the mid, tid etc around).
  31  Plus the fid to examine and notify private data.
  32 *****************************************************************************/
  33
  34 struct change_notify {
  35         struct change_notify *next, *prev;
  36         files_struct *fsp;
  37         connection_struct *conn;
  38         uint32 flags;
  39         char request_buf[smb_size];
  40         void *change_data;
  41 };
  42
  43 static struct change_notify *change_notify_list;
  44
  45 /****************************************************************************
  46  Setup the common parts of the return packet and send it.
  47 *****************************************************************************/
  48 static void change_notify_reply_packet(char *inbuf, NTSTATUS error_code)
  49 {
  50         char outbuf[smb_size+38];
  51
  52         memset(outbuf, '\0', sizeof(outbuf));
  53         construct_reply_common(inbuf, outbuf);
  54
  55         ERROR_NT(error_code);
  56
  57         /*
  58          * Seems NT needs a transact command with an error code
  59          * in it. This is a longer packet than a simple error.
  60          */
  61         set_message(outbuf,18,0,False);
  62
  63         if (!send_smb(smbd_server_fd(),outbuf))
  64                 exit_server("change_notify_reply_packet: send_smb failed.");
  65 }
  66
  67 /****************************************************************************
  68  Remove an entry from the list and free it, also closing any
  69  directory handle if necessary.
  70 *****************************************************************************/
  71
  72 static void change_notify_remove(struct change_notify *cnbp)
  73 {
  74         cnotify->remove_notify(cnbp->change_data);
  75         DLIST_REMOVE(change_notify_list, cnbp);
  76         ZERO_STRUCTP(cnbp);
  77         SAFE_FREE(cnbp);
  78 }
  79
  80 /****************************************************************************
  81  Delete entries by fnum from the change notify pending queue.
  82 *****************************************************************************/
  83
  84 void remove_pending_change_notify_requests_by_fid(files_struct *fsp)
  85 {
  86         struct change_notify *cnbp, *next;
  87
  88         for (cnbp=change_notify_list; cnbp; cnbp=next) {
  89                 next=cnbp->next;
  90                 if (cnbp->fsp->fnum == fsp->fnum) {
  91                         change_notify_remove(cnbp);
  92                 }
  93         }
  94 }
  95
  96 /****************************************************************************
  97  Delete entries by mid from the change notify pending queue. Always send reply.
  98 *****************************************************************************/
  99
 100 void remove_pending_change_notify_requests_by_mid(int mid)
 101 {
 102         struct change_notify *cnbp, *next;
 103
 104         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 105                 next=cnbp->next;
 106                 if(SVAL(cnbp->request_buf,smb_mid) == mid) {
 107                         change_notify_reply_packet(cnbp->request_buf,NT_STATUS_CANCELLED);
 108                         change_notify_remove(cnbp);
 109                 }
 110         }
 111 }
 112
 113 /****************************************************************************
 114  Delete entries by filename and cnum from the change notify pending queue.
 115  Always send reply.
 116 *****************************************************************************/
 117
 118 void remove_pending_change_notify_requests_by_filename(files_struct *fsp)
 119 {
 120         struct change_notify *cnbp, *next;
 121
 122         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 123                 next=cnbp->next;
 124                 /*
 125                  * We know it refers to the same directory if the connection number and
 126                  * the filename are identical.
 127                  */
 128                 if((cnbp->fsp->conn == fsp->conn) && strequal(cnbp->fsp->fsp_name,fsp->fsp_name)) {
 129                         change_notify_reply_packet(cnbp->request_buf,NT_STATUS_CANCELLED);
 130                         change_notify_remove(cnbp);
 131                 }
 132         }
 133 }
 134
 135 /****************************************************************************
 136  Return true if there are pending change notifies.
 137 ****************************************************************************/
 138
 139 int change_notify_timeout(void)
 140 {
 141         return cnotify->select_time;
 142 }
 143
 144 /****************************************************************************
 145  Process the change notify queue. Note that this is only called as root.
 146  Returns True if there are still outstanding change notify requests on the
 147  queue.
 148 *****************************************************************************/
 149
 150 BOOL process_pending_change_notify_queue(time_t t)
 151 {
 152         struct change_notify *cnbp, *next;
 153         uint16 vuid;
 154
 155         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 156                 next=cnbp->next;
 157
 158                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID : SVAL(cnbp->request_buf,smb_uid);
 159
 160                 if (cnotify->check_notify(cnbp->conn, vuid, cnbp->fsp->fsp_name, cnbp->flags, cnbp->change_data, t)) {
 161                         DEBUG(10,("process_pending_change_notify_queue: dir %s changed !\n", cnbp->fsp->fsp_name ));
 162                         change_notify_reply_packet(cnbp->request_buf,STATUS_NOTIFY_ENUM_DIR);
 163                         change_notify_remove(cnbp);
 164                 }
 165         }
 166
 167         return (change_notify_list != NULL);
 168 }
 169
 170 /****************************************************************************
 171  Now queue an entry on the notify change list.
 172  We only need to save smb_size bytes from this incoming packet
 173  as we will always by returning a 'read the directory yourself'
 174  error.
 175 ****************************************************************************/
 176
 177 BOOL change_notify_set(char *inbuf, files_struct *fsp, connection_struct *conn, uint32 flags)
 178 {
 179         struct change_notify *cnbp;
 180
 181         if((cnbp = (struct change_notify *)malloc(sizeof(*cnbp))) == NULL) {
 182                 DEBUG(0,("call_nt_transact_notify_change: malloc fail !\n" ));
 183                 return -1;
 184         }
 185
 186         ZERO_STRUCTP(cnbp);
 187
 188         memcpy(cnbp->request_buf, inbuf, smb_size);
 189         cnbp->fsp = fsp;
 190         cnbp->conn = conn;
 191         cnbp->flags = flags;
 192         cnbp->change_data = cnotify->register_notify(conn, fsp->fsp_name, flags);
 193
 194         if (!cnbp->change_data) {
 195                 SAFE_FREE(cnbp);
 196                 return False;
 197         }
 198
 199         DLIST_ADD(change_notify_list, cnbp);
 200
 201         return True;
 202 }
 203
 204 /****************************************************************************
 205  Initialise the change notify subsystem.
 206 ****************************************************************************/
 207
 208 BOOL init_change_notify(void)
 209 {
 210 #if HAVE_KERNEL_CHANGE_NOTIFY
 211         cnotify = kernel_notify_init();
 212 #endif
 213         if (!cnotify) cnotify = hash_notify_init();
 214
 215         if (!cnotify) {
 216                 DEBUG(0,("Failed to init change notify system\n"));
 217                 return False;
 218         }
 219
 220         return True;
 221 }