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 extern int DEBUGLEVEL;
  26
  27 static struct cnotify_fns *cnotify;
  28
  29 /****************************************************************************
  30  This is the structure to queue to implement NT change
  31  notify. It consists of smb_size bytes stored from the
  32  transact command (to keep the mid, tid etc around).
  33  Plus the fid to examine and notify private data
  34 *****************************************************************************/
  35
  36 struct change_notify {
  37         struct change_notify *next, *prev;
  38         files_struct *fsp;
  39         connection_struct *conn;
  40         uint32 flags;
  41         char request_buf[smb_size];
  42         void *change_data;
  43 };
  44
  45 static struct change_notify *change_notify_list;
  46
  47 /****************************************************************************
  48  Setup the common parts of the return packet and send it.
  49 *****************************************************************************/
  50 static void change_notify_reply_packet(char *inbuf, NTSTATUS error_code)
  51 {
  52         char outbuf[smb_size+38];
  53
  54         memset(outbuf, '\0', sizeof(outbuf));
  55         construct_reply_common(inbuf, outbuf);
  56
  57         ERROR_NT(error_code);
  58
  59         /*
  60          * Seems NT needs a transact command with an error code
  61          * in it. This is a longer packet than a simple error.
  62          */
  63         set_message(outbuf,18,0,False);
  64
  65         if (!send_smb(smbd_server_fd(),outbuf))
  66                 exit_server("change_notify_reply_packet: send_smb failed.\n");
  67 }
  68
  69 /****************************************************************************
  70 remove an entry from the list and free it, also closing any
  71 directory handle if necessary
  72 Notice the horrible stuff we have to do because this is a singly linked list.
  73 *****************************************************************************/
  74 static void change_notify_remove(struct change_notify *cnbp)
  75 {
  76         cnotify->remove_notify(cnbp->change_data);
  77         DLIST_REMOVE(change_notify_list, cnbp);
  78         ZERO_STRUCTP(cnbp);
  79         SAFE_FREE(cnbp);
  80 }
  81
  82
  83 /****************************************************************************
  84  Delete entries by fnum from the change notify pending queue.
  85 *****************************************************************************/
  86 void remove_pending_change_notify_requests_by_fid(files_struct *fsp)
  87 {
  88         struct change_notify *cnbp, *next;
  89
  90         for (cnbp=change_notify_list; cnbp; cnbp=next) {
  91                 next=cnbp->next;
  92                 if (cnbp->fsp->fnum == fsp->fnum) {
  93                         change_notify_remove(cnbp);
  94                 }
  95         }
  96 }
  97
  98 /****************************************************************************
  99  Delete entries by mid from the change notify pending queue. Always send reply.
 100 *****************************************************************************/
 101 void remove_pending_change_notify_requests_by_mid(int mid)
 102 {
 103         struct change_notify *cnbp, *next;
 104
 105         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 106                 next=cnbp->next;
 107                 if(SVAL(cnbp->request_buf,smb_mid) == mid) {
 108                         change_notify_reply_packet(cnbp->request_buf,NT_STATUS_CANCELLED);
 109                         change_notify_remove(cnbp);
 110                 }
 111         }
 112 }
 113
 114 /****************************************************************************
 115  Delete entries by filename and cnum from the change notify pending queue.
 116  Always send reply.
 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 int change_notify_timeout(void)
 139 {
 140         return cnotify->select_time;
 141 }
 142
 143 /****************************************************************************
 144  Process the change notify queue. Note that this is only called as root.
 145  Returns True if there are still outstanding change notify requests on the
 146  queue.
 147 *****************************************************************************/
 148 BOOL process_pending_change_notify_queue(time_t t)
 149 {
 150         struct change_notify *cnbp, *next;
 151         uint16 vuid;
 152
 153         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 154                 next=cnbp->next;
 155
 156                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID : SVAL(cnbp->request_buf,smb_uid);
 157
 158                 if (cnotify->check_notify(cnbp->conn, vuid, cnbp->fsp->fsp_name, cnbp->flags, cnbp->change_data, t)) {
 159                         change_notify_reply_packet(cnbp->request_buf,STATUS_NOTIFY_ENUM_DIR);
 160                         change_notify_remove(cnbp);
 161                 }
 162         }
 163
 164         return (change_notify_list != NULL);
 165 }
 166
 167 /****************************************************************************
 168    * Now queue an entry on the notify change list.
 169    * We only need to save smb_size bytes from this incoming packet
 170    * as we will always by returning a 'read the directory yourself'
 171    * error.
 172 ****************************************************************************/
 173 BOOL change_notify_set(char *inbuf, files_struct *fsp, connection_struct *conn, uint32 flags)
 174 {
 175         struct change_notify *cnbp;
 176
 177         if((cnbp = (struct change_notify *)malloc(sizeof(*cnbp))) == NULL) {
 178                 DEBUG(0,("call_nt_transact_notify_change: malloc fail !\n" ));
 179                 return -1;
 180         }
 181
 182         ZERO_STRUCTP(cnbp);
 183
 184         memcpy(cnbp->request_buf, inbuf, smb_size);
 185         cnbp->fsp = fsp;
 186         cnbp->conn = conn;
 187         cnbp->flags = flags;
 188         cnbp->change_data = cnotify->register_notify(conn, fsp->fsp_name, flags);
 189
 190         if (!cnbp->change_data) {
 191                 SAFE_FREE(cnbp);
 192                 return False;
 193         }
 194
 195         DLIST_ADD(change_notify_list, cnbp);
 196
 197         return True;
 198 }
 199
 200
 201 /****************************************************************************
 202 initialise the change notify subsystem
 203 ****************************************************************************/
 204 BOOL init_change_notify(void)
 205 {
 206 #if HAVE_KERNEL_CHANGE_NOTIFY
 207         cnotify = kernel_notify_init();
 208 #endif
 209         if (!cnotify) cnotify = hash_notify_init();
 210
 211         if (!cnotify) {
 212                 DEBUG(0,("Failed to init change notify system\n"));
 213                 return False;
 214         }
 215
 216         return True;
 217 }