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