source/smbd/notify.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    change notify handling
   4    Copyright (C) Andrew Tridgell 2000
   5    Copyright (C) Jeremy Allison 1994-1998
   6
   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.
  11
  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.
  16
  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.
  20 */
  21
  22 #include "includes.h"
  23
  24 static struct cnotify_fns *cnotify;
  25
  26 /****************************************************************************
  27  This is the structure to queue to implement NT change
  28  notify. It consists of smb_size bytes stored from the
  29  transact command (to keep the mid, tid etc around).
  30  Plus the fid to examine and notify private data.
  31 *****************************************************************************/
  32
  33 struct change_notify {
  34         struct change_notify *next, *prev;
  35         files_struct *fsp;
  36         connection_struct *conn;
  37         uint32 flags;
  38         char request_buf[smb_size];
  39         void *change_data;
  40 };
  41
  42 static struct change_notify *change_notify_list;
  43
  44 /****************************************************************************
  45  Setup the common parts of the return packet and send it.
  46 *****************************************************************************/
  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 = SMB_MALLOC_P(struct change_notify)) == NULL) {
 182                 DEBUG(0,("change_notify_set: 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         /* Push the MID of this packet on the signing queue. */
 202         srv_defer_sign_response(SVAL(inbuf,smb_mid));
 203
 204         return True;
 205 }
 206
 207 /****************************************************************************
 208  Initialise the change notify subsystem.
 209 ****************************************************************************/
 210
 211 BOOL init_change_notify(void)
 212 {
 213 #if HAVE_KERNEL_CHANGE_NOTIFY
 214         if (lp_kernel_change_notify())
 215                 cnotify = kernel_notify_init();
 216 #endif
 217         if (!cnotify) cnotify = hash_notify_init();
 218
 219         if (!cnotify) {
 220                 DEBUG(0,("Failed to init change notify system\n"));
 221                 return False;
 222         }
 223
 224         return True;
 225 }