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 3 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, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "../lib/util/dlinklist.h"
  22 #include "smb_server/smb_server.h"
  23 #include "ntvfs/ntvfs.h"
  24
  25
  26 /****************************************************************************
  27 init the handle structures
  28 ****************************************************************************/
  29 NTSTATUS smbsrv_init_handles(struct smbsrv_tcon *tcon, uint32_t limit)
  30 {
  31         /*
  32          * the idr_* functions take 'int' as limit,
  33          * and only work with a max limit 0x00FFFFFF
  34          */
  35         limit &= 0x00FFFFFF;
  36
  37         tcon->handles.idtree_hid        = idr_init(tcon);
  38         NT_STATUS_HAVE_NO_MEMORY(tcon->handles.idtree_hid);
  39         tcon->handles.idtree_limit      = limit;
  40         tcon->handles.list              = NULL;
  41
  42         return NT_STATUS_OK;
  43 }
  44
  45 /****************************************************************************
  46 find a handle given a handle id
  47 ****************************************************************************/
  48 static struct smbsrv_handle *smbsrv_handle_find(struct smbsrv_handles_context *handles_ctx,
  49                                                 uint32_t hid, struct timeval request_time)
  50 {
  51         void *p;
  52         struct smbsrv_handle *handle;
  53
  54         if (hid == 0) return NULL;
  55
  56         if (hid > handles_ctx->idtree_limit) return NULL;
  57
  58         p = idr_find(handles_ctx->idtree_hid, hid);
  59         if (!p) return NULL;
  60
  61         handle = talloc_get_type(p, struct smbsrv_handle);
  62         if (!handle) return NULL;
  63
  64         /* only give it away when the ntvfs subsystem has made the handle valid */
  65         if (!handle->ntvfs) return NULL;
  66
  67         handle->statistics.last_use_time = request_time;
  68
  69         return handle;
  70 }
  71
  72 struct smbsrv_handle *smbsrv_smb_handle_find(struct smbsrv_tcon *smb_tcon,
  73                                              uint16_t fnum, struct timeval request_time)
  74 {
  75         return smbsrv_handle_find(&smb_tcon->handles, fnum, request_time);
  76 }
  77
  78 struct smbsrv_handle *smbsrv_smb2_handle_find(struct smbsrv_tcon *smb_tcon,
  79                                               uint32_t hid, struct timeval request_time)
  80 {
  81         return smbsrv_handle_find(&smb_tcon->handles, hid, request_time);
  82 }
  83
  84 /*
  85   destroy a connection structure
  86 */
  87 static int smbsrv_handle_destructor(struct smbsrv_handle *handle)
  88 {
  89         struct smbsrv_handles_context *handles_ctx;
  90
  91         handles_ctx = &handle->tcon->handles;
  92
  93         idr_remove(handles_ctx->idtree_hid, handle->hid);
  94         DLIST_REMOVE(handles_ctx->list, handle);
  95         DLIST_REMOVE(handle->session->handles, &handle->session_item);
  96
  97         /* tell the ntvfs backend that we are disconnecting */
  98         if (handle->ntvfs) {
  99                 talloc_free(handle->ntvfs);
 100                 handle->ntvfs = NULL;
 101         }
 102
 103         return 0;
 104 }
 105
 106 /*
 107   find first available handle slot
 108 */
 109 struct smbsrv_handle *smbsrv_handle_new(struct smbsrv_session *session,
 110                                         struct smbsrv_tcon *tcon,
 111                                         TALLOC_CTX *mem_ctx,
 112                                         struct timeval request_time)
 113 {
 114         struct smbsrv_handles_context *handles_ctx = &tcon->handles;
 115         struct smbsrv_handle *handle;
 116         int i;
 117
 118         handle = talloc_zero(mem_ctx, struct smbsrv_handle);
 119         if (!handle) return NULL;
 120         handle->tcon    = tcon;
 121         handle->session = session;
 122
 123         i = idr_get_new_above(handles_ctx->idtree_hid, handle, 1, handles_ctx->idtree_limit);
 124         if (i == -1) {
 125                 DEBUG(1,("ERROR! Out of handle structures\n"));
 126                 goto failed;
 127         }
 128         handle->hid = i;
 129         handle->session_item.handle = handle;
 130
 131         DLIST_ADD(handles_ctx->list, handle);
 132         DLIST_ADD(session->handles, &handle->session_item);
 133         talloc_set_destructor(handle, smbsrv_handle_destructor);
 134
 135         /* now fill in some statistics */
 136         handle->statistics.open_time            = request_time;
 137         handle->statistics.last_use_time        = request_time;
 138
 139         return handle;
 140
 141 failed:
 142         talloc_free(handle);
 143         return NULL;
 144 }