source4/smb_server/handle.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Manage smbsrv_handle structures
   4    Copyright (C) Stefan Metzmacher 2006
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22 #include "lib/util/dlinklist.h"
  23 #include "smb_server/smb_server.h"
  24 #include "ntvfs/ntvfs.h"
  25
  26
  27 /****************************************************************************
  28 init the handle structures
  29 ****************************************************************************/
  30 NTSTATUS smbsrv_init_handles(struct smbsrv_tcon *tcon, uint64_t limit)
  31 {
  32         /*
  33          * the idr_* functions take 'int' as limit,
  34          * and only work with a max limit 0x00FFFFFF
  35          */
  36         limit &= 0x00FFFFFF;
  37
  38         tcon->handles.idtree_hid        = idr_init(tcon);
  39         NT_STATUS_HAVE_NO_MEMORY(tcon->handles.idtree_hid);
  40         tcon->handles.idtree_limit      = limit;
  41         tcon->handles.list              = NULL;
  42
  43         return NT_STATUS_OK;
  44 }
  45
  46 /****************************************************************************
  47 find a handle given a handle id
  48 ****************************************************************************/
  49 static struct smbsrv_handle *smbsrv_handle_find(struct smbsrv_handles_context *handles_ctx,
  50                                                 uint64_t hid, struct timeval request_time)
  51 {
  52         void *p;
  53         struct smbsrv_handle *handle;
  54
  55         if (hid == 0) return NULL;
  56
  57         if (hid > handles_ctx->idtree_limit) return NULL;
  58
  59         p = idr_find(handles_ctx->idtree_hid, hid);
  60         if (!p) return NULL;
  61
  62         handle = talloc_get_type(p, struct smbsrv_handle);
  63         if (!handle) return NULL;
  64
  65         /* only give it away when the ntvfs subsystem has made the handle valid */
  66         if (!handle->ntvfs) return NULL;
  67
  68         handle->statistics.last_use_time = request_time;
  69
  70         return handle;
  71 }
  72
  73 struct smbsrv_handle *smbsrv_smb_handle_find(struct smbsrv_tcon *smb_tcon,
  74                                              uint16_t fnum, struct timeval request_time)
  75 {
  76         return smbsrv_handle_find(&smb_tcon->handles, fnum, request_time);
  77 }
  78
  79 struct smbsrv_handle *smbsrv_smb2_handle_find(struct smbsrv_tcon *smb_tcon,
  80                                               uint64_t hid, struct timeval request_time)
  81 {
  82         return smbsrv_handle_find(&smb_tcon->handles, hid, request_time);
  83 }
  84
  85 /*
  86   destroy a connection structure
  87 */
  88 static int smbsrv_handle_destructor(struct smbsrv_handle *handle)
  89 {
  90         struct smbsrv_handles_context *handles_ctx;
  91
  92         handles_ctx = &handle->tcon->handles;
  93
  94         idr_remove(handles_ctx->idtree_hid, handle->hid);
  95         DLIST_REMOVE(handles_ctx->list, handle);
  96         DLIST_REMOVE(handle->session->handles, &handle->session_item);
  97
  98         /* tell the ntvfs backend that we are disconnecting */
  99         if (handle->ntvfs) {
 100                 talloc_free(handle->ntvfs);
 101                 handle->ntvfs = NULL;
 102         }
 103
 104         return 0;
 105 }
 106
 107 /*
 108   find first available handle slot
 109 */
 110 struct smbsrv_handle *smbsrv_handle_new(struct smbsrv_session *session,
 111                                         struct smbsrv_tcon *tcon,
 112                                         TALLOC_CTX *mem_ctx,
 113                                         struct timeval request_time)
 114 {
 115         struct smbsrv_handles_context *handles_ctx = &tcon->handles;
 116         struct smbsrv_handle *handle;
 117         int i;
 118
 119         handle = talloc_zero(mem_ctx, struct smbsrv_handle);
 120         if (!handle) return NULL;
 121         handle->tcon    = tcon;
 122         handle->session = session;
 123
 124         i = idr_get_new_above(handles_ctx->idtree_hid, handle, 1, handles_ctx->idtree_limit);
 125         if (i == -1) {
 126                 DEBUG(1,("ERROR! Out of handle structures\n"));
 127                 goto failed;
 128         }
 129         handle->hid = i;
 130         handle->session_item.handle = handle;
 131
 132         DLIST_ADD(handles_ctx->list, handle);
 133         DLIST_ADD(session->handles, &handle->session_item);
 134         talloc_set_destructor(handle, smbsrv_handle_destructor);
 135
 136         /* now fill in some statistics */
 137         handle->statistics.open_time            = request_time;
 138         handle->statistics.last_use_time        = request_time;
 139
 140         return handle;
 141
 142 failed:
 143         talloc_free(handle);
 144         return NULL;
 145 }