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