source4/ntptr/ntptr_base.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    NTPTR base code
   5
   6    Copyright (C) Stefan (metze) Metzmacher 2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22 /*
  23   this implements the core code for all NTPTR modules. Backends register themselves here.
  24 */
  25
  26 #include "includes.h"
  27 #include "ntptr/ntptr.h"
  28 #include "dlinklist.h"
  29
  30 /* the list of currently registered NTPTR backends */
  31 static struct ntptr_backend {
  32         const struct ntptr_ops *ops;
  33 } *backends = NULL;
  34 static int num_backends;
  35
  36 /*
  37   register a NTPTR backend.
  38
  39   The 'name' can be later used by other backends to find the operations
  40   structure for this backend.
  41 */
  42 NTSTATUS ntptr_register(const void *_ops)
  43 {
  44         const struct ntptr_ops *ops = _ops;
  45         struct ntptr_ops *new_ops;
  46
  47         if (ntptr_backend_byname(ops->name) != NULL) {
  48                 /* its already registered! */
  49                 DEBUG(0,("NTPTR backend '%s' already registered\n",
  50                          ops->name));
  51                 return NT_STATUS_OBJECT_NAME_COLLISION;
  52         }
  53
  54         backends = realloc_p(backends, struct ntptr_backend, num_backends+1);
  55         if (!backends) {
  56                 smb_panic("out of memory in ntptr_register");
  57         }
  58
  59         new_ops = smb_xmemdup(ops, sizeof(*ops));
  60         new_ops->name = smb_xstrdup(ops->name);
  61
  62         backends[num_backends].ops = new_ops;
  63
  64         num_backends++;
  65
  66         DEBUG(3,("NTPTR backend '%s'\n",
  67                  ops->name));
  68
  69         return NT_STATUS_OK;
  70 }
  71
  72
  73 /*
  74   return the operations structure for a named backend
  75 */
  76 const struct ntptr_ops *ntptr_backend_byname(const char *name)
  77 {
  78         int i;
  79
  80         for (i=0;i<num_backends;i++) {
  81                 if (strcmp(backends[i].ops->name, name) == 0) {
  82                         return backends[i].ops;
  83                 }
  84         }
  85
  86         return NULL;
  87 }
  88
  89
  90 /*
  91   return the NTPTR interface version, and the size of some critical types
  92   This can be used by backends to either detect compilation errors, or provide
  93   multiple implementations for different smbd compilation options in one module
  94 */
  95 static const struct ntptr_critical_sizes critical_sizes = {
  96         .interface_version              = NTPTR_INTERFACE_VERSION,
  97         .sizeof_ntptr_critical_sizes    = sizeof(struct ntptr_critical_sizes),
  98         .sizeof_ntptr_context           = sizeof(struct ntptr_context),
  99         .sizeof_ntptr_ops               = sizeof(struct ntptr_ops),
 100 };
 101 const struct ntptr_critical_sizes *ntptr_interface_version(void)
 102 {
 103         return &critical_sizes;
 104 }
 105
 106 /*
 107   create a ntptr_context with a specified NTPTR backend
 108 */
 109 NTSTATUS ntptr_init_context(TALLOC_CTX *mem_ctx, const char *providor, struct ntptr_context **_ntptr)
 110 {
 111         NTSTATUS status;
 112         struct ntptr_context *ntptr;
 113
 114         if (!providor) {
 115                 return NT_STATUS_INTERNAL_ERROR;
 116         }
 117
 118         ntptr = talloc(mem_ctx, struct ntptr_context);
 119         NT_STATUS_HAVE_NO_MEMORY(ntptr);
 120         ntptr->private_data     = NULL;
 121         ntptr->ops              = ntptr_backend_byname(providor);
 122
 123         if (!ntptr->ops) {
 124                 DEBUG(1,("ntptr_init_context: failed to find NTPTR providor='%s'\n",
 125                          providor));
 126                 return NT_STATUS_INTERNAL_ERROR;
 127         }
 128
 129         status = ntptr->ops->init_context(ntptr);
 130         NT_STATUS_NOT_OK_RETURN(status);
 131
 132         *_ntptr = ntptr;
 133         return NT_STATUS_OK;
 134 }