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         show_msg(outbuf);
  64         if (!send_smb(smbd_server_fd(),outbuf))
  65                 exit_server("change_notify_reply_packet: send_smb failed.");
  66 }
  67
  68 /****************************************************************************
  69  Remove an entry from the list and free it, also closing any
  70  directory handle if necessary.
  71 *****************************************************************************/
  72
  73 static void change_notify_remove(struct change_notify *cnbp)
  74 {
  75         cnotify->remove_notify(cnbp->change_data);
  76         DLIST_REMOVE(change_notify_list, cnbp);
  77         ZERO_STRUCTP(cnbp);
  78         SAFE_FREE(cnbp);
  79 }
  80
  81 /****************************************************************************
  82  Delete entries by fnum from the change notify pending queue.
  83 *****************************************************************************/
  84
  85 void remove_pending_change_notify_requests_by_fid(files_struct *fsp)
  86 {
  87         struct change_notify *cnbp, *next;
  88
  89         for (cnbp=change_notify_list; cnbp; cnbp=next) {
  90                 next=cnbp->next;
  91                 if (cnbp->fsp->fnum == fsp->fnum) {
  92                         change_notify_remove(cnbp);
  93                 }
  94         }
  95 }
  96
  97 /****************************************************************************
  98  Delete entries by mid from the change notify pending queue. Always send reply.
  99 *****************************************************************************/
 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
 119 void remove_pending_change_notify_requests_by_filename(files_struct *fsp)
 120 {
 121         struct change_notify *cnbp, *next;
 122
 123         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 124                 next=cnbp->next;
 125                 /*
 126                  * We know it refers to the same directory if the connection number and
 127                  * the filename are identical.
 128                  */
 129                 if((cnbp->fsp->conn == fsp->conn) && strequal(cnbp->fsp->fsp_name,fsp->fsp_name)) {
 130                         change_notify_reply_packet(cnbp->request_buf,NT_STATUS_CANCELLED);
 131                         change_notify_remove(cnbp);
 132                 }
 133         }
 134 }
 135
 136 /****************************************************************************
 137  Return true if there are pending change notifies.
 138 ****************************************************************************/
 139
 140 int change_notify_timeout(void)
 141 {
 142         return cnotify->select_time;
 143 }
 144
 145 /****************************************************************************
 146  Process the change notify queue. Note that this is only called as root.
 147  Returns True if there are still outstanding change notify requests on the
 148  queue.
 149 *****************************************************************************/
 150
 151 BOOL process_pending_change_notify_queue(time_t t)
 152 {
 153         struct change_notify *cnbp, *next;
 154         uint16 vuid;
 155
 156         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 157                 next=cnbp->next;
 158
 159                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID : SVAL(cnbp->request_buf,smb_uid);
 160
 161                 if (cnotify->check_notify(cnbp->conn, vuid, cnbp->fsp->fsp_name, cnbp->flags, cnbp->change_data, t)) {
 162                         DEBUG(10,("process_pending_change_notify_queue: dir %s changed !\n", cnbp->fsp->fsp_name ));
 163                         change_notify_reply_packet(cnbp->request_buf,STATUS_NOTIFY_ENUM_DIR);
 164                         change_notify_remove(cnbp);
 165                 }
 166         }
 167
 168         return (change_notify_list != NULL);
 169 }
 170
 171 /****************************************************************************
 172  Now queue an entry on the notify change list.
 173  We only need to save smb_size bytes from this incoming packet
 174  as we will always by returning a 'read the directory yourself'
 175  error.
 176 ****************************************************************************/
 177
 178 BOOL change_notify_set(char *inbuf, files_struct *fsp, connection_struct *conn, uint32 flags)
 179 {
 180         struct change_notify *cnbp;
 181
 182         if((cnbp = SMB_MALLOC_P(struct change_notify)) == NULL) {
 183                 DEBUG(0,("change_notify_set: malloc fail !\n" ));
 184                 return -1;
 185         }
 186
 187         ZERO_STRUCTP(cnbp);
 188
 189         memcpy(cnbp->request_buf, inbuf, smb_size);
 190         cnbp->fsp = fsp;
 191         cnbp->conn = conn;
 192         cnbp->flags = flags;
 193         cnbp->change_data = cnotify->register_notify(conn, fsp->fsp_name, flags);
 194
 195         if (!cnbp->change_data) {
 196                 SAFE_FREE(cnbp);
 197                 return False;
 198         }
 199
 200         DLIST_ADD(change_notify_list, cnbp);
 201
 202         /* Push the MID of this packet on the signing queue. */
 203         srv_defer_sign_response(SVAL(inbuf,smb_mid));
 204
 205         return True;
 206 }
 207
 208 /****************************************************************************
 209  Initialise the change notify subsystem.
 210 ****************************************************************************/
 211
 212 BOOL init_change_notify(void)
 213 {
 214 #if HAVE_KERNEL_CHANGE_NOTIFY
 215         if (lp_kernel_change_notify())
 216                 cnotify = kernel_notify_init();
 217 #endif
 218         if (!cnotify) cnotify = hash_notify_init();
 219
 220         if (!cnotify) {
 221                 DEBUG(0,("Failed to init change notify system\n"));
 222                 return False;
 223         }
 224
 225         return True;
 226 }