source3/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, NTSTATUS status)
  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_reply_packet(cnbp->request_buf,status);
  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
 102 void remove_pending_change_notify_requests_by_mid(int mid)
 103 {
 104         struct change_notify *cnbp, *next;
 105
 106         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 107                 next=cnbp->next;
 108                 if(SVAL(cnbp->request_buf,smb_mid) == mid) {
 109                         change_notify_reply_packet(cnbp->request_buf,NT_STATUS_CANCELLED);
 110                         change_notify_remove(cnbp);
 111                 }
 112         }
 113 }
 114
 115 /****************************************************************************
 116  Delete entries by filename and cnum from the change notify pending queue.
 117  Always send reply.
 118 *****************************************************************************/
 119
 120 void remove_pending_change_notify_requests_by_filename(files_struct *fsp, NTSTATUS status)
 121 {
 122         struct change_notify *cnbp, *next;
 123
 124         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 125                 next=cnbp->next;
 126                 /*
 127                  * We know it refers to the same directory if the connection number and
 128                  * the filename are identical.
 129                  */
 130                 if((cnbp->fsp->conn == fsp->conn) && strequal(cnbp->fsp->fsp_name,fsp->fsp_name)) {
 131                         change_notify_reply_packet(cnbp->request_buf,status);
 132                         change_notify_remove(cnbp);
 133                 }
 134         }
 135 }
 136
 137 /****************************************************************************
 138  Set the current change notify timeout to the lowest value across all service
 139  values.
 140 ****************************************************************************/
 141
 142 void set_change_notify_timeout(int val)
 143 {
 144         if (val > 0) {
 145                 cnotify->select_time = MIN(cnotify->select_time, val);
 146         }
 147 }
 148
 149 /****************************************************************************
 150  Longest time to sleep for before doing a change notify scan.
 151 ****************************************************************************/
 152
 153 int change_notify_timeout(void)
 154 {
 155         return cnotify->select_time;
 156 }
 157
 158 /****************************************************************************
 159  Process the change notify queue. Note that this is only called as root.
 160  Returns True if there are still outstanding change notify requests on the
 161  queue.
 162 *****************************************************************************/
 163
 164 BOOL process_pending_change_notify_queue(time_t t)
 165 {
 166         struct change_notify *cnbp, *next;
 167         uint16 vuid;
 168
 169         for (cnbp=change_notify_list; cnbp; cnbp=next) {
 170                 next=cnbp->next;
 171
 172                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID : SVAL(cnbp->request_buf,smb_uid);
 173
 174                 if (cnotify->check_notify(cnbp->conn, vuid, cnbp->fsp->fsp_name, cnbp->flags, cnbp->change_data, t)) {
 175                         DEBUG(10,("process_pending_change_notify_queue: dir %s changed !\n", cnbp->fsp->fsp_name ));
 176                         change_notify_reply_packet(cnbp->request_buf,STATUS_NOTIFY_ENUM_DIR);
 177                         change_notify_remove(cnbp);
 178                 }
 179         }
 180
 181         return (change_notify_list != NULL);
 182 }
 183
 184 /****************************************************************************
 185  Now queue an entry on the notify change list.
 186  We only need to save smb_size bytes from this incoming packet
 187  as we will always by returning a 'read the directory yourself'
 188  error.
 189 ****************************************************************************/
 190
 191 BOOL change_notify_set(char *inbuf, files_struct *fsp, connection_struct *conn, uint32 flags)
 192 {
 193         struct change_notify *cnbp;
 194
 195         if((cnbp = SMB_MALLOC_P(struct change_notify)) == NULL) {
 196                 DEBUG(0,("change_notify_set: malloc fail !\n" ));
 197                 return -1;
 198         }
 199
 200         ZERO_STRUCTP(cnbp);
 201
 202         memcpy(cnbp->request_buf, inbuf, smb_size);
 203         cnbp->fsp = fsp;
 204         cnbp->conn = conn;
 205         cnbp->flags = flags;
 206         cnbp->change_data = cnotify->register_notify(conn, fsp->fsp_name, flags);
 207
 208         if (!cnbp->change_data) {
 209                 SAFE_FREE(cnbp);
 210                 return False;
 211         }
 212
 213         DLIST_ADD(change_notify_list, cnbp);
 214
 215         /* Push the MID of this packet on the signing queue. */
 216         srv_defer_sign_response(SVAL(inbuf,smb_mid));
 217
 218         return True;
 219 }
 220
 221 int change_notify_fd(void)
 222 {
 223         if (cnotify) {
 224                 return cnotify->notification_fd;
 225         }
 226
 227         return -1;
 228 }
 229
 230 /****************************************************************************
 231  Initialise the change notify subsystem.
 232 ****************************************************************************/
 233
 234 BOOL init_change_notify(void)
 235 {
 236         cnotify = NULL;
 237
 238 #if HAVE_KERNEL_CHANGE_NOTIFY
 239         if (cnotify == NULL && lp_kernel_change_notify())
 240                 cnotify = kernel_notify_init();
 241 #endif
 242 #if HAVE_FAM_CHANGE_NOTIFY
 243         if (cnotify == NULL && lp_fam_change_notify())
 244                 cnotify = fam_notify_init();
 245 #endif
 246         if (!cnotify) cnotify = hash_notify_init();
 247
 248         if (!cnotify) {
 249                 DEBUG(0,("Failed to init change notify system\n"));
 250                 return False;
 251         }
 252
 253         return True;
 254 }