release/src/router/samba3/source/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         /* This call should reset any possible non-fatal errors that
  44            occured since last call to dl* functions */
  45         error = sys_dlerror();
  46
  47         if(!handle) {
  48                 int level = is_probe ? 3 : 0;
  49                 DEBUG(level, ("Error loading module '%s': %s\n", module_name, error ? error : ""));
  50                 return NT_STATUS_UNSUCCESSFUL;
  51         }
  52
  53         init = (init_module_function *)sys_dlsym(handle, "init_module");
  54
  55         /* we must check sys_dlerror() to determine if it worked, because
  56            sys_dlsym() can validly return NULL */
  57         error = sys_dlerror();
  58         if (error) {
  59                 DEBUG(0, ("Error trying to resolve symbol 'init_module' in %s: %s\n",
  60                           module_name, error));
  61                 return NT_STATUS_UNSUCCESSFUL;
  62         }
  63
  64         DEBUG(2, ("Module '%s' loaded\n", module_name));
  65
  66         status = init();
  67         if (!NT_STATUS_IS_OK(status)) {
  68                 DEBUG(0, ("Module '%s' initialization failed: %s\n",
  69                             module_name, get_friendly_nt_error_msg(status)));
  70         }
  71
  72         return status;
  73 }
  74
  75 NTSTATUS smb_load_module(const char *module_name)
  76 {
  77         return do_smb_load_module(module_name, False);
  78 }
  79
  80 /* Load all modules in list and return number of
  81  * modules that has been successfully loaded */
  82 int smb_load_modules(const char **modules)
  83 {
  84         int i;
  85         int success = 0;
  86
  87         for(i = 0; modules[i]; i++){
  88                 if(NT_STATUS_IS_OK(smb_load_module(modules[i]))) {
  89                         success++;
  90                 }
  91         }
  92
  93         DEBUG(2, ("%d modules successfully loaded\n", success));
  94
  95         return success;
  96 }
  97
  98 NTSTATUS smb_probe_module(const char *subsystem, const char *module)
  99 {
 100         pstring full_path;
 101
 102         /* Check for absolute path */
 103
 104         /* if we make any 'samba multibyte string'
 105            calls here, we break
 106            for loading string modules */
 107
 108         DEBUG(5, ("Probing module '%s'\n", module));
 109
 110         if (module[0] == '/')
 111                 return do_smb_load_module(module, True);
 112
 113         pstrcpy(full_path, lib_path(subsystem));
 114         pstrcat(full_path, "/");
 115         pstrcat(full_path, module);
 116         pstrcat(full_path, ".");
 117         pstrcat(full_path, shlib_ext());
 118
 119         DEBUG(5, ("Probing module '%s': Trying to load from %s\n", module, full_path));
 120
 121         return do_smb_load_module(full_path, True);
 122 }
 123
 124 #else /* HAVE_DLOPEN */
 125
 126 NTSTATUS smb_load_module(const char *module_name)
 127 {
 128         DEBUG(0,("This samba executable has not been built with plugin support\n"));
 129         return NT_STATUS_NOT_SUPPORTED;
 130 }
 131
 132 int smb_load_modules(const char **modules)
 133 {
 134         DEBUG(0,("This samba executable has not been built with plugin support\n"));
 135         return -1;
 136 }
 137
 138 NTSTATUS smb_probe_module(const char *subsystem, const char *module)
 139 {
 140         DEBUG(0,("This samba executable has not been built with plugin support, not probing\n"));
 141         return NT_STATUS_NOT_SUPPORTED;
 142 }
 143
 144 #endif /* HAVE_DLOPEN */
 145
 146 void init_modules(void)
 147 {
 148         /* FIXME: This can cause undefined symbol errors :
 149          *  smb_register_vfs() isn't available in nmbd, for example */
 150         if(lp_preload_modules())
 151                 smb_load_modules(lp_preload_modules());
 152 }
 153
 154
 155 /***************************************************************************
 156  * This Function registers a idle event
 157  *
 158  * the registered funtions are run periodically
 159  * and maybe shutdown idle connections (e.g. to an LDAP server)
 160  ***************************************************************************/
 161 static smb_event_id_t smb_idle_event_id = 1;
 162
 163 struct smb_idle_list_ent {
 164         struct smb_idle_list_ent *prev,*next;
 165         smb_event_id_t id;
 166         smb_idle_event_fn *fn;
 167         void *data;
 168         time_t interval;
 169         time_t lastrun;
 170 };
 171
 172 static struct smb_idle_list_ent *smb_idle_event_list = NULL;
 173
 174 smb_event_id_t smb_register_idle_event(smb_idle_event_fn *fn, void *data, time_t interval)
 175 {
 176         struct smb_idle_list_ent *event;
 177
 178         if (!fn) {
 179                 return SMB_EVENT_ID_INVALID;
 180         }
 181
 182         event = SMB_MALLOC_P(struct smb_idle_list_ent);
 183         if (!event) {
 184                 DEBUG(0,("malloc() failed!\n"));
 185                 return SMB_EVENT_ID_INVALID;
 186         }
 187         event->fn = fn;
 188         event->data = data;
 189         event->interval = interval;
 190         event->lastrun = 0;
 191         event->id = smb_idle_event_id++;
 192
 193         DLIST_ADD(smb_idle_event_list,event);
 194
 195         return event->id;
 196 }
 197
 198 BOOL smb_unregister_idle_event(smb_event_id_t id)
 199 {
 200         struct smb_idle_list_ent *event = smb_idle_event_list;
 201
 202         while(event) {
 203                 if (event->id == id) {
 204                         DLIST_REMOVE(smb_idle_event_list,event);
 205                         SAFE_FREE(event);
 206                         return True;
 207                 }
 208                 event = event->next;
 209         }
 210
 211         return False;
 212 }
 213
 214 void smb_run_idle_events(time_t now)
 215 {
 216         struct smb_idle_list_ent *event = smb_idle_event_list;
 217
 218         while (event) {
 219                 struct smb_idle_list_ent *next = event->next;
 220                 time_t interval;
 221
 222                 if (event->interval <= 0) {
 223                         interval = SMB_IDLE_EVENT_DEFAULT_INTERVAL;
 224                 } else if (event->interval >= SMB_IDLE_EVENT_MIN_INTERVAL) {
 225                         interval = event->interval;
 226                 } else {
 227                         interval = SMB_IDLE_EVENT_MIN_INTERVAL;
 228                 }
 229                 if (now >(event->lastrun+interval)) {
 230                         event->lastrun = now;
 231                         event->fn(&event->data,&event->interval,now);
 232                 }
 233                 event = next;
 234         }
 235
 236         return;
 237 }