source4/smbd/process_model.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    process model manager - main loop
   4    Copyright (C) Andrew Tridgell 1992-2003
   5    Copyright (C) James J Myers 2003 <myersjj@samba.org>
   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 3 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, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "smbd/process_model.h"
  23 #include "param/param.h"
  24 #include "lib/util/samba_modules.h"
  25
  26 /* the list of currently registered process models */
  27 static struct process_model {
  28         const struct model_ops *ops;
  29         bool initialised;
  30 } *models = NULL;
  31 static int num_models;
  32
  33
  34 /*
  35   return the operations structure for a named backend of the specified type
  36 */
  37 static struct process_model *process_model_byname(const char *name)
  38 {
  39         int i;
  40
  41         for (i=0;i<num_models;i++) {
  42                 if (strcmp(models[i].ops->name, name) == 0) {
  43                         return &models[i];
  44                 }
  45         }
  46
  47         return NULL;
  48 }
  49
  50
  51 /*
  52   setup the events for the chosen process model
  53 */
  54 _PUBLIC_ const struct model_ops *process_model_startup(const char *model)
  55 {
  56         struct process_model *m;
  57
  58         m = process_model_byname(model);
  59         if (m == NULL) {
  60                 DBG_ERR("Unknown process model '%s'\n", model);
  61                 exit(-1);
  62         }
  63
  64         if (!m->initialised) {
  65                 m->initialised = true;
  66                 m->ops->model_init();
  67         }
  68
  69         return m->ops;
  70 }
  71
  72 /*
  73   register a process model.
  74
  75   The 'name' can be later used by other backends to find the operations
  76   structure for this backend.
  77 */
  78 _PUBLIC_ NTSTATUS register_process_model(const struct model_ops *ops)
  79 {
  80         if (process_model_byname(ops->name) != NULL) {
  81                 /* its already registered! */
  82                 DBG_ERR("PROCESS_MODEL '%s' already registered\n", ops->name);
  83                 return NT_STATUS_OBJECT_NAME_COLLISION;
  84         }
  85
  86         models = talloc_realloc(NULL, models, struct process_model, num_models+1);
  87         if (!models) {
  88                 smb_panic("out of memory in register_process_model");
  89         }
  90
  91         models[num_models].ops = ops;
  92         models[num_models].initialised = false;
  93
  94         num_models++;
  95
  96         DBG_NOTICE("PROCESS_MODEL '%s' registered\n", ops->name);
  97
  98         return NT_STATUS_OK;
  99 }
 100
 101 _PUBLIC_ NTSTATUS process_model_init(struct loadparm_context *lp_ctx)
 102 {
 103 #define _MODULE_PROTO(init) extern NTSTATUS init(TALLOC_CTX *);
 104         STATIC_process_model_MODULES_PROTO;
 105         init_module_fn static_init[] = { STATIC_process_model_MODULES };
 106         init_module_fn *shared_init;
 107         static bool initialised;
 108
 109         if (initialised) {
 110                 return NT_STATUS_OK;
 111         }
 112         initialised = true;
 113
 114         shared_init = load_samba_modules(NULL, "process_model");
 115
 116         run_init_functions(NULL, static_init);
 117         run_init_functions(NULL, shared_init);
 118
 119         talloc_free(shared_init);
 120
 121         return NT_STATUS_OK;
 122 }
 123
 124 /*
 125   return the PROCESS_MODEL module version, and the size of some critical types
 126   This can be used by process model modules to either detect compilation errors, or provide
 127   multiple implementations for different smbd compilation options in one module
 128 */
 129 const struct process_model_critical_sizes *process_model_version(void)
 130 {
 131         static const struct process_model_critical_sizes critical_sizes = {
 132                 PROCESS_MODEL_VERSION,
 133                 sizeof(struct model_ops)
 134         };
 135
 136         return &critical_sizes;
 137 }