source3/lib/module.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    module loading system
   4
   5    Copyright (C) Jelmer Vernooij 2002-2003
   6    Copyright (C) Stefan (metze) Metzmacher 2003
   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 #include "includes.h"
  24
  25 #ifdef HAVE_DLOPEN
  26
  27 /* Load a dynamic module.  Only log a level 0 error if we are not checking
  28    for the existence of a module (probling). */
  29
  30 static NTSTATUS do_smb_load_module(const char *module_name, BOOL is_probe)
  31 {
  32         void *handle;
  33         init_module_function *init;
  34         NTSTATUS status;
  35         const char *error;
  36
  37         /* Always try to use LAZY symbol resolving; if the plugin has
  38          * backwards compatibility, there might be symbols in the
  39          * plugin referencing to old (removed) functions
  40          */
  41         handle = sys_dlopen(module_name, RTLD_LAZY);
  42
  43         if(!handle) {
  44                 int level = is_probe ? 3 : 0;
  45                 DEBUG(level, ("Error loading module '%s': %s\n", module_name,
  46                               sys_dlerror()));
  47
  48                 return NT_STATUS_UNSUCCESSFUL;
  49         }
  50
  51         init = (init_module_function *)sys_dlsym(handle, "init_module");
  52
  53         /* we must check sys_dlerror() to determine if it worked, because
  54            sys_dlsym() can validly return NULL */
  55         error = sys_dlerror();
  56         if (error) {
  57                 DEBUG(0, ("Error trying to resolve symbol 'init_module' in %s: %s\n",
  58                           module_name, error));
  59                 return NT_STATUS_UNSUCCESSFUL;
  60         }
  61
  62         status = init();
  63
  64         DEBUG(2, ("Module '%s' loaded\n", module_name));
  65
  66         return status;
  67 }
  68
  69 NTSTATUS smb_load_module(const char *module_name)
  70 {
  71         return do_smb_load_module(module_name, False);
  72 }
  73
  74 /* Load all modules in list and return number of
  75  * modules that has been successfully loaded */
  76 int smb_load_modules(const char **modules)
  77 {
  78         int i;
  79         int success = 0;
  80
  81         for(i = 0; modules[i]; i++){
  82                 if(NT_STATUS_IS_OK(smb_load_module(modules[i]))) {
  83                         success++;
  84                 }
  85         }
  86
  87         DEBUG(2, ("%d modules successfully loaded\n", success));
  88
  89         return success;
  90 }
  91
  92 NTSTATUS smb_probe_module(const char *subsystem, const char *module)
  93 {
  94         pstring full_path;
  95
  96         /* Check for absolute path */
  97
  98         /* if we make any 'samba multibyte string'
  99            calls here, we break
 100            for loading string modules */
 101
 102         DEBUG(5, ("Probing module '%s'\n", module));
 103
 104         if (module[0] == '/')
 105                 return do_smb_load_module(module, True);
 106
 107         pstrcpy(full_path, lib_path(subsystem));
 108         pstrcat(full_path, "/");
 109         pstrcat(full_path, module);
 110         pstrcat(full_path, ".");
 111         pstrcat(full_path, shlib_ext());
 112
 113         DEBUG(5, ("Probing module '%s': Trying to load from %s\n", module, full_path));
 114
 115         return do_smb_load_module(full_path, True);
 116 }
 117
 118 #else /* HAVE_DLOPEN */
 119
 120 NTSTATUS smb_load_module(const char *module_name)
 121 {
 122         DEBUG(0,("This samba executable has not been built with plugin support\n"));
 123         return NT_STATUS_NOT_SUPPORTED;
 124 }
 125
 126 int smb_load_modules(const char **modules)
 127 {
 128         DEBUG(0,("This samba executable has not been built with plugin support\n"));
 129         return -1;
 130 }
 131
 132 NTSTATUS smb_probe_module(const char *subsystem, const char *module)
 133 {
 134         DEBUG(0,("This samba executable has not been built with plugin support, not probing\n"));
 135         return NT_STATUS_NOT_SUPPORTED;
 136 }
 137
 138 #endif /* HAVE_DLOPEN */
 139
 140 void init_modules(void)
 141 {
 142         /* FIXME: This can cause undefined symbol errors :
 143          *  smb_register_vfs() isn't available in nmbd, for example */
 144         if(lp_preload_modules())
 145                 smb_load_modules(lp_preload_modules());
 146 }
 147
 148
 149 /***************************************************************************
 150  * This Function registers a idle event
 151  *
 152  * the registered funtions are run periodically
 153  * and maybe shutdown idle connections (e.g. to an LDAP server)
 154  ***************************************************************************/
 155 static smb_event_id_t smb_idle_event_id = 1;
 156
 157 struct smb_idle_list_ent {
 158         struct smb_idle_list_ent *prev,*next;
 159         smb_event_id_t id;
 160         smb_idle_event_fn *fn;
 161         void *data;
 162         time_t interval;
 163         time_t lastrun;
 164 };
 165
 166 static struct smb_idle_list_ent *smb_idle_event_list = NULL;
 167
 168 smb_event_id_t smb_register_idle_event(smb_idle_event_fn *fn, void *data, time_t interval)
 169 {
 170         struct smb_idle_list_ent *event;
 171
 172         if (!fn) {
 173                 return SMB_EVENT_ID_INVALID;
 174         }
 175
 176         event = (struct smb_idle_list_ent *)malloc(sizeof(struct smb_idle_list_ent));
 177         if (!event) {
 178                 DEBUG(0,("malloc() failed!\n"));
 179                 return SMB_EVENT_ID_INVALID;
 180         }
 181         event->fn = fn;
 182         event->data = data;
 183         event->interval = interval;
 184         event->lastrun = 0;
 185         event->id = smb_idle_event_id++;
 186
 187         DLIST_ADD(smb_idle_event_list,event);
 188
 189         return event->id;
 190 }
 191
 192 BOOL smb_unregister_idle_event(smb_event_id_t id)
 193 {
 194         struct smb_idle_list_ent *event = smb_idle_event_list;
 195
 196         while(event) {
 197                 if (event->id == id) {
 198                         DLIST_REMOVE(smb_idle_event_list,event);
 199                         SAFE_FREE(event);
 200                         return True;
 201                 }
 202                 event = event->next;
 203         }
 204
 205         return False;
 206 }
 207
 208 void smb_run_idle_events(time_t now)
 209 {
 210         struct smb_idle_list_ent *event = smb_idle_event_list;
 211
 212         while (event) {
 213                 struct smb_idle_list_ent *next = event->next;
 214                 time_t interval;
 215
 216                 if (event->interval <= 0) {
 217                         interval = SMB_IDLE_EVENT_DEFAULT_INTERVAL;
 218                 } else if (event->interval >= SMB_IDLE_EVENT_MIN_INTERVAL) {
 219                         interval = event->interval;
 220                 } else {
 221                         interval = SMB_IDLE_EVENT_MIN_INTERVAL;
 222                 }
 223                 if (now >(event->lastrun+interval)) {
 224                         event->lastrun = now;
 225                         event->fn(&event->data,&event->interval,now);
 226                 }
 227                 event = next;
 228         }
 229
 230         return;
 231 }
 232
 233 /***************************************************************************
 234  * This Function registers a exit event
 235  *
 236  * the registered functions are run on exit()
 237  * and maybe shutdown idle connections (e.g. to an LDAP server)
 238  ***************************************************************************/
 239
 240 struct smb_exit_list_ent {
 241         struct smb_exit_list_ent *prev,*next;
 242         smb_event_id_t id;
 243         smb_exit_event_fn *fn;
 244         void *data;
 245 };
 246
 247 static struct smb_exit_list_ent *smb_exit_event_list = NULL;
 248
 249 smb_event_id_t smb_register_exit_event(smb_exit_event_fn *fn, void *data)
 250 {
 251         struct smb_exit_list_ent *event;
 252         static smb_event_id_t smb_exit_event_id = 1;
 253
 254         if (!fn) {
 255                 return SMB_EVENT_ID_INVALID;
 256         }
 257
 258         event = (struct smb_exit_list_ent *)malloc(sizeof(struct smb_exit_list_ent));
 259         if (!event) {
 260                 DEBUG(0,("malloc() failed!\n"));
 261                 return SMB_EVENT_ID_INVALID;
 262         }
 263         event->fn = fn;
 264         event->data = data;
 265         event->id = smb_exit_event_id++;
 266
 267         DLIST_ADD(smb_exit_event_list,event);
 268
 269         return event->id;
 270 }
 271
 272 BOOL smb_unregister_exit_event(smb_event_id_t id)
 273 {
 274         struct smb_exit_list_ent *event = smb_exit_event_list;
 275
 276         while(event) {
 277                 if (event->id == id) {
 278                         DLIST_REMOVE(smb_exit_event_list,event);
 279                         SAFE_FREE(event);
 280                         return True;
 281                 }
 282                 event = event->next;
 283         }
 284
 285         return False;
 286 }
 287
 288 void smb_run_exit_events(void)
 289 {
 290         struct smb_exit_list_ent *event = smb_exit_event_list;
 291         struct smb_exit_list_ent *tmp = NULL;
 292
 293         while (event) {
 294                 event->fn(&event->data);
 295                 tmp = event;
 296                 event = event->next;
 297                 /* exit event should only run one time :-)*/
 298                 SAFE_FREE(tmp);
 299         }
 300
 301         /* the list is empty now...*/
 302         smb_exit_event_list = NULL;
 303
 304         return;
 305 }