plugin-loader: Properly support compilation without dlopen()/dlsym() etc.

This only works if plugins are built monolithically and linked statically.

Closes strongswan/strongswan#2615

diff --git a/src/libstrongswan/plugins/plugin_loader.c b/src/libstrongswan/plugins/plugin_loader.c
index 30b1aeed082c4bdcc9674ad099dd0808e4b49128..786b18332888117432fc0b53559c1f4217107e0c 100644 (file)
--- a/src/libstrongswan/plugins/plugin_loader.c
+++ b/src/libstrongswan/plugins/plugin_loader.c
@@ -191,10 +191,12 @@ struct plugin_entry_t {
         */
        bool critical;
 
+#ifdef HAVE_DLADDR
        /**
         * dlopen handle, if in separate lib
         */
        void *handle;
+#endif
 
        /**
         * List of features, as provided_feature_t
@@ -208,10 +210,12 @@ struct plugin_entry_t {
 static void plugin_entry_destroy(plugin_entry_t *entry)
 {
        DESTROY_IF(entry->plugin);
+#ifdef HAVE_DLADDR
        if (entry->handle)
        {
                dlclose(entry->handle);
        }
+#endif
        entry->features->destroy(entry->features);
        free(entry);
 }
@@ -369,11 +373,14 @@ static status_t create_plugin(private_plugin_loader_t *this, void *handle,
        {
                constructor = plugin_constructors->get(plugin_constructors, name);
        }
+#elif defined(HAVE_DLADDR)
        if (!constructor)
-#endif
        {
                constructor = dlsym(handle, create);
        }
+#else
+       #error Neither dynamic linking nor static plugin constructors are supported!
+#endif
        if (!constructor)
        {
                return NOT_FOUND;
@@ -412,8 +419,12 @@ static plugin_entry_t *load_plugin(private_plugin_loader_t *this, char *name,
 {
        char create[128];
        plugin_entry_t *entry;
-       void *handle;
+       void *handle = NULL;
+
+#ifdef HAVE_DLADDR
        int flag = RTLD_LAZY;
+       handle = RTLD_DEFAULT;
+#endif
 
        if (snprintf(create, sizeof(create), "%s_plugin_create",
                                 name) >= sizeof(create))
@@ -421,7 +432,7 @@ static plugin_entry_t *load_plugin(private_plugin_loader_t *this, char *name,
                return NULL;
        }
        translate(create, "-", "_");
-       switch (create_plugin(this, RTLD_DEFAULT, name, create, FALSE, critical,
+       switch (create_plugin(this, handle, name, create, FALSE, critical,
                                                  &entry))
        {
                case SUCCESS:
@@ -447,6 +458,7 @@ static plugin_entry_t *load_plugin(private_plugin_loader_t *this, char *name,
                        return NULL;
                }
        }
+#ifdef HAVE_DLADDR
        if (lib->settings->get_bool(lib->settings, "%s.dlopen_use_rtld_now",
                                                                FALSE, lib->ns))
        {
@@ -480,6 +492,9 @@ static plugin_entry_t *load_plugin(private_plugin_loader_t *this, char *name,
        entry->handle = handle;
        this->plugins->insert_last(this->plugins, entry);
        return entry;
+#else
+       return NULL;
+#endif
 }
 
 CALLBACK(feature_filter, bool,
@@ -1347,10 +1362,12 @@ METHOD(plugin_loader_t, unload, void,
        unload_features(this);
        while (this->plugins->remove_last(this->plugins, (void**)&entry) == SUCCESS)
        {
+#ifdef HAVE_DLADDR
                if (lib->leak_detective)
                {       /* keep handle to report leaks properly */
                        entry->handle = NULL;
                }
+#endif
                unregister_features(this, entry);
                plugin_entry_destroy(entry);
        }
@@ -1474,9 +1491,12 @@ plugin_loader_t *plugin_loader_create()
                .features = hashlist_create(
                                                        (hashtable_hash_t)registered_feature_hash,
                                                        (hashtable_equals_t)registered_feature_equals, 64),
-               .get_features = dlsym(RTLD_DEFAULT, "plugin_loader_feature_filter"),
        );
 
+#ifdef HAVE_DLADDR
+       this->get_features = dlsym(RTLD_DEFAULT, "plugin_loader_feature_filter");
+#endif
+
        if (!this->get_features)
        {
                this->get_features = get_features_default;