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 static void change_notify_reply_packet(char *inbuf, NTSTATUS error_code)
  48 {
  49         char outbuf[smb_size+38];
  50
  51         memset(outbuf, '\0', sizeof(outbuf));
  52         construct_reply_common(inbuf, outbuf);
  53
  54         ERROR_NT(error_code);
  55
  56         /*
  57          * Seems NT needs a transact command with an error code
  58          * in it. This is a longer packet than a simple error.
  59          */
  60         set_message(outbuf,18,0,False);
  61
  62         if (!send_smb(smbd_server_fd(),outbuf))
  63                 exit_server("change_notify_reply_packet: send_smb failed.");
  64 }
  65
  66 /****************************************************************************
  67  Remove an entry from the list and free it, also closing any
  68  directory handle if necessary.
  69 *****************************************************************************/
  70
  71 static void change_notify_remove(struct change_notify *cnbp)
  72 {
  73         cnotify->remove_notify(cnbp->change_data);
  74         DLIST_REMOVE(change_notify_list, cnbp);
  75         ZERO_STRUCTP(cnbp);
  76         SAFE_FREE(cnbp);
  77 }
  78
  79 /****************************************************************************
  80  Delete entries by fnum from the change notify pending queue.
  81 *****************************************************************************/
  82
  83 void remove_pending_change_notify_requests_by_fid(files_struct *fsp)
  84 {
  85         struct change_notify *cnbp, *next;
  86
  87         for (cnbp=change_notify_list; cnbp; cnbp=next) {
  88                 next=cnbp->next;
  89                 if (cnbp->fsp->fnum == fsp->fnum) {
  90                         change_notify_remove(cnbp);
  91                 }
  92         }
  93 }
  94
  95 /****************************************************************************
  96  Delete entries by mid from the change notify pending queue. Always send reply.
  97 *****************************************************************************/
  98
  99 void remove_pending_change_notify_requests_by_mid(int mid)
 100 {
 101         struct change_notify *cnbp, *next;
 102
 103         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 104                 next=cnbp->next;
 105                 if(SVAL(cnbp->request_buf,smb_mid) == mid) {
 106                         change_notify_reply_packet(cnbp->request_buf,NT_STATUS_CANCELLED);
 107                         change_notify_remove(cnbp);
 108                 }
 109         }
 110 }
 111
 112 /****************************************************************************
 113  Delete entries by filename and cnum from the change notify pending queue.
 114  Always send reply.
 115 *****************************************************************************/
 116
 117 void remove_pending_change_notify_requests_by_filename(files_struct *fsp)
 118 {
 119         struct change_notify *cnbp, *next;
 120
 121         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 122                 next=cnbp->next;
 123                 /*
 124                  * We know it refers to the same directory if the connection number and
 125                  * the filename are identical.
 126                  */
 127                 if((cnbp->fsp->conn == fsp->conn) && strequal(cnbp->fsp->fsp_name,fsp->fsp_name)) {
 128                         change_notify_reply_packet(cnbp->request_buf,NT_STATUS_CANCELLED);
 129                         change_notify_remove(cnbp);
 130                 }
 131         }
 132 }
 133
 134 /****************************************************************************
 135  Return true if there are pending change notifies.
 136 ****************************************************************************/
 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
 149 BOOL process_pending_change_notify_queue(time_t t)
 150 {
 151         struct change_notify *cnbp, *next;
 152         uint16 vuid;
 153
 154         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 155                 next=cnbp->next;
 156
 157                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID : SVAL(cnbp->request_buf,smb_uid);
 158
 159                 if (cnotify->check_notify(cnbp->conn, vuid, cnbp->fsp->fsp_name, cnbp->flags, cnbp->change_data, t)) {
 160                         DEBUG(10,("process_pending_change_notify_queue: dir %s changed !\n", cnbp->fsp->fsp_name ));
 161                         change_notify_reply_packet(cnbp->request_buf,STATUS_NOTIFY_ENUM_DIR);
 162                         change_notify_remove(cnbp);
 163                 }
 164         }
 165
 166         return (change_notify_list != NULL);
 167 }
 168
 169 /****************************************************************************
 170  Now queue an entry on the notify change list.
 171  We only need to save smb_size bytes from this incoming packet
 172  as we will always by returning a 'read the directory yourself'
 173  error.
 174 ****************************************************************************/
 175
 176 BOOL change_notify_set(char *inbuf, files_struct *fsp, connection_struct *conn, uint32 flags)
 177 {
 178         struct change_notify *cnbp;
 179
 180         if((cnbp = (struct change_notify *)malloc(sizeof(*cnbp))) == NULL) {
 181                 DEBUG(0,("call_nt_transact_notify_change: malloc fail !\n" ));
 182                 return -1;
 183         }
 184
 185         ZERO_STRUCTP(cnbp);
 186
 187         memcpy(cnbp->request_buf, inbuf, smb_size);
 188         cnbp->fsp = fsp;
 189         cnbp->conn = conn;
 190         cnbp->flags = flags;
 191         cnbp->change_data = cnotify->register_notify(conn, fsp->fsp_name, flags);
 192
 193         if (!cnbp->change_data) {
 194                 SAFE_FREE(cnbp);
 195                 return False;
 196         }
 197
 198         DLIST_ADD(change_notify_list, cnbp);
 199
 200         return True;
 201 }
 202
 203 /****************************************************************************
 204  Initialise the change notify subsystem.
 205 ****************************************************************************/
 206
 207 BOOL init_change_notify(void)
 208 {
 209 #if HAVE_KERNEL_CHANGE_NOTIFY
 210         if (lp_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 }