src/libstrongswan/plugins/plugin_loader.c

   1 /*
   2  * Copyright (C) 2007 Martin Willi
   3  * Hochschule fuer Technik Rapperswil
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation; either version 2 of the License, or (at your
   8  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * for more details.
  14  *
  15  * $Id$
  16  */
  17
  18 #include "plugin_loader.h"
  19
  20 #include <dlfcn.h>
  21
  22 #include <debug.h>
  23 #include <utils/linked_list.h>
  24 #include <plugins/plugin.h>
  25
  26 typedef struct private_plugin_loader_t private_plugin_loader_t;
  27
  28 /**
  29  * private data of plugin_loader
  30  */
  31 struct private_plugin_loader_t {
  32
  33         /**
  34          * public functions
  35          */
  36         plugin_loader_t public;
  37
  38         /**
  39          * list of loaded plugins
  40          */
  41         linked_list_t *plugins;
  42 };
  43
  44 /**
  45  * Implementation of plugin_loader_t.load_plugins.
  46  */
  47 static int load(private_plugin_loader_t *this, char *path, char *prefix)
  48 {
  49         enumerator_t *enumerator;
  50         char *file, *ending, *rel;
  51         void *handle;
  52         int count = 0;
  53
  54         enumerator = enumerator_create_directory(path);
  55         if (!enumerator)
  56         {
  57                 DBG1("opening plugin directory %s failed", path);
  58                 return 0;
  59         }
  60         DBG1("loading plugins from %s", path);
  61         while (enumerator->enumerate(enumerator, &rel, &file, NULL))
  62         {
  63                 plugin_t *plugin;
  64                 plugin_constructor_t constructor;
  65
  66                 ending = file + strlen(file) - 3;
  67                 if (ending <= file || !streq(ending, ".so"))
  68                 {       /* only process .so libraries */
  69                         continue;
  70                 }
  71                 if (!strneq(prefix, rel, strlen(prefix)))
  72                 {
  73                         continue;
  74                 }
  75                 handle = dlopen(file, RTLD_LAZY);
  76                 if (handle == NULL)
  77                 {
  78                         DBG1("loading plugin %s failed: %s", rel, dlerror());
  79                         continue;
  80                 }
  81                 constructor = dlsym(handle, "plugin_create");
  82                 if (constructor == NULL)
  83                 {
  84                         DBG1("plugin %s has no plugin_create() function, skipped", rel);
  85                         dlclose(handle);
  86                         continue;
  87                 }
  88                 plugin = constructor();
  89                 if (plugin == NULL)
  90                 {
  91                         DBG1("plugin %s constructor failed, skipping", rel);
  92                         dlclose(handle);
  93                         continue;
  94                 }
  95                 DBG1("plugin %s loaded successfully", rel);
  96                 /* insert in front to destroy them in reverse order */
  97                 this->plugins->insert_last(this->plugins, plugin);
  98                 /* we do not store or free dlopen() handles, leak_detective requires
  99                  * the modules to keep loaded until leak report */
 100                 count++;
 101         }
 102         enumerator->destroy(enumerator);
 103         return count;
 104 }
 105
 106 /**
 107  * Implementation of plugin_loader_t.destroy
 108  */
 109 static void destroy(private_plugin_loader_t *this)
 110 {
 111         this->plugins->destroy_offset(this->plugins, offsetof(plugin_t, destroy));
 112         free(this);
 113 }
 114
 115 /*
 116  * see header file
 117  */
 118 plugin_loader_t *plugin_loader_create()
 119 {
 120         private_plugin_loader_t *this = malloc_thing(private_plugin_loader_t);
 121
 122         this->public.load = (int(*)(plugin_loader_t*, char *path, char *prefix))load;
 123         this->public.destroy = (void(*)(plugin_loader_t*))destroy;
 124
 125         this->plugins = linked_list_create();
 126
 127         return &this->public;
 128 }
 129