Version 0.1.0 from FTP

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@14 65c4cc65-6c06-0410-ace0-fbb531ad65f3

loader.c

@@ -0,0 +1,322 @@
+/*
+ * Asterisk -- A telephony toolkit for Linux.
+ *
+ * Module Loader
+ * 
+ * Copyright (C) 1999, Adtran Inc. and Linux Support Services, LLC
+ *
+ * Mark Spencer <markster@linux-support.net>
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License
+ */
+
+#include <stdio.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <asterisk/module.h>
+#include <asterisk/options.h>
+#include <asterisk/config.h>
+#include <asterisk/logger.h>
+#include <dlfcn.h>
+#define __USE_GNU
+#include <pthread.h>
+#include "asterisk.h"
+
+struct module {
+	int (*load_module)(void);
+	int (*unload_module)(void);
+	int (*usecount)(void);
+	char *(*description)(void);
+	void *lib;
+	char resource[256];
+	struct module *next;
+};
+
+static struct loadupdate {
+	int (*updater)(void);
+	struct loadupdate *next;
+} *updaters = NULL;
+
+static pthread_mutex_t modlock = PTHREAD_MUTEX_INITIALIZER;
+
+static struct module *module_list=NULL;
+
+int ast_unload_resource(char *resource_name, int force)
+{
+	struct module *m, *ml = NULL;
+	int res = -1;
+	if (pthread_mutex_lock(&modlock))
+		ast_log(LOG_WARNING, "Failed to lock\n");
+	m = module_list;
+	while(m) {
+		if (!strcasecmp(m->resource, resource_name)) {
+			if ((res = m->usecount()) > 0)  {
+				if (force) 
+					ast_log(LOG_WARNING, "Warning:  Forcing removal of module %s with use count %d\n", resource_name, res);
+				else {
+					ast_log(LOG_WARNING, "Soft unload failed, '%s' has use count %d\n", resource_name, res);
+					pthread_mutex_unlock(&modlock);
+					return -1;
+				}
+			}
+			res = m->unload_module();
+			if (res) {
+				ast_log(LOG_WARNING, "Firm unload failed for %s\n", resource_name);
+				if (force <= AST_FORCE_FIRM) {
+					pthread_mutex_unlock(&modlock);
+					return -1;
+				} else
+					ast_log(LOG_WARNING, "** Dangerous **: Unloading resource anyway, at user request\n");
+			}
+			if (ml)
+				ml->next = m->next;
+			else
+				module_list = m->next;
+			dlclose(m->lib);
+			free(m);
+		}
+		ml = m;
+		m = m->next;
+	}
+	pthread_mutex_unlock(&modlock);
+	ast_update_use_count();
+	return res;
+}
+
+int ast_load_resource(char *resource_name)
+{
+	static char fn[256];
+	int errors=0;
+	int res;
+	struct module *m = malloc(sizeof(struct module));
+	if (!m) {
+		ast_log(LOG_WARNING, "Out of memory\n");
+		return -1;
+	}
+	strncpy(m->resource, resource_name, sizeof(m->resource));
+	if (resource_name[0] == '/') {
+		strncpy(fn, resource_name, sizeof(fn));
+	} else {
+		snprintf(fn, sizeof(fn), "%s/%s", AST_MODULE_DIR, resource_name);
+	}
+	m->lib = dlopen(fn, RTLD_NOW  | RTLD_GLOBAL);
+	if (!m->lib) {
+		ast_log(LOG_WARNING, "%s\n", dlerror());
+		free(m);
+		return -1;
+	}
+	m->load_module = dlsym(m->lib, "load_module");
+	if (!m->load_module) {
+		ast_log(LOG_WARNING, "No load_module in module %s\n", fn);
+		errors++;
+	}
+	m->unload_module = dlsym(m->lib, "unload_module");
+	if (!m->unload_module) {
+		ast_log(LOG_WARNING, "No unload_module in module %s\n", fn);
+		errors++;
+	}
+	m->usecount = dlsym(m->lib, "usecount");
+	if (!m->usecount) {
+		ast_log(LOG_WARNING, "No usecount in module %s\n", fn);
+		errors++;
+	}
+	m->description = dlsym(m->lib, "description");
+	if (!m->description) {
+		ast_log(LOG_WARNING, "No description in module %s\n", fn);
+		errors++;
+	}
+	if (errors) {
+		ast_log(LOG_WARNING, "%d error(s) loading module %s, aborted\n", errors, fn);
+		dlclose(m->lib);
+		free(m);
+		return -1;
+	}
+	if (option_verbose) 
+		ast_verbose( " => (%s)\n", m->description());
+	if ((res = m->load_module())) {
+		ast_log(LOG_WARNING, "%s: load_module failed, returning %d\n", m->resource, fn, res);
+		free(m);
+		return -1;
+	}
+	if (pthread_mutex_lock(&modlock))
+		ast_log(LOG_WARNING, "Failed to lock\n");
+	m->next = module_list;
+	module_list = m;
+	pthread_mutex_unlock(&modlock);
+	ast_update_use_count();
+	return 0;
+}	
+
+int ast_resource_exists(char *resource)
+{
+	struct module *m;
+	if (pthread_mutex_lock(&modlock))
+		ast_log(LOG_WARNING, "Failed to lock\n");
+	m = module_list;
+	while(m) {
+		if (!strcasecmp(resource, m->resource))
+			break;
+		m = m->next;
+	}
+	pthread_mutex_unlock(&modlock);
+	if (m)
+		return -1;
+	else
+		return 0;
+}
+
+int load_modules()
+{
+	struct ast_config *cfg;
+	struct ast_variable *v;
+	if (option_verbose) 
+		ast_verbose( "Asterisk Dynamic Loader Starting:\n");
+	cfg = ast_load(AST_MODULE_CONFIG);
+	if (cfg) {
+		/* Load explicitly defined modules */
+		v = ast_variable_browse(cfg, "modules");
+		while(v) {
+			if (!strcasecmp(v->name, "load")) {
+				if (option_debug && !option_verbose)
+					ast_log(LOG_DEBUG, "Loading module %s\n", v->value);
+				if (option_verbose) {
+					ast_verbose( " [%s]", v->value);
+					fflush(stdout);
+				}
+				if (ast_load_resource(v->value)) {
+					ast_log(LOG_WARNING, "Loading module %s failed!\n", v->value);
+					if (cfg)
+						ast_destroy(cfg);
+					return -1;
+				}
+			}
+			v=v->next;
+		}
+	}
+	if (!cfg || ast_true(ast_variable_retrieve(cfg, "modules", "autoload"))) {
+		/* Load all modules */
+		DIR *mods;
+		struct dirent *d;
+		mods = opendir(AST_MODULE_DIR);
+		if (mods) {
+			while((d = readdir(mods))) {
+				/* Must end in .so to load it.  */
+				if ((strlen(d->d_name) > 3) && 
+				    !strcasecmp(d->d_name + strlen(d->d_name) - 3, ".so") &&
+					!ast_resource_exists(d->d_name)) {
+					/* It's a shared library -- Just be sure we're allowed to load it -- kinda
+					   an inefficient way to do it, but oh well. */
+					if (cfg) {
+						v = ast_variable_browse(cfg, "modules");
+						while(v) {
+							if (!strcasecmp(v->name, "noload") &&
+							    !strcasecmp(v->value, d->d_name)) 
+								break;
+							v = v->next;
+						}
+						if (v) {
+							if (option_verbose) {
+								ast_verbose( VERBOSE_PREFIX_1 "[skipping %s]\n", d->d_name);
+								fflush(stdout);
+							}
+							continue;
+						}
+						
+					}
+				    if (option_debug && !option_verbose)
+						ast_log(LOG_DEBUG, "Loading module %s\n", d->d_name);
+					if (option_verbose) {
+						ast_verbose( VERBOSE_PREFIX_1 "[%s]", d->d_name);
+						fflush(stdout);
+					}
+					if (ast_load_resource(d->d_name)) {
+						ast_log(LOG_WARNING, "Loading module %s failed!\n", d->d_name);
+						if (cfg)
+							ast_destroy(cfg);
+						return -1;
+					}
+				}
+			};
+		} else {
+			if (!option_quiet)
+				ast_log(LOG_WARNING, "Unable to open modules directory " AST_MODULE_DIR ".\n");
+		}
+	} 
+	ast_destroy(cfg);
+	return 0;
+}
+
+void ast_update_use_count(void)
+{
+	/* Notify any module monitors that the use count for a 
+	   resource has changed */
+	struct loadupdate *m;
+	if (pthread_mutex_lock(&modlock))
+		ast_log(LOG_WARNING, "Failed to lock\n");
+	m = updaters;
+	while(m) {
+		m->updater();
+		m = m->next;
+	}
+	pthread_mutex_unlock(&modlock);
+	
+}
+
+int ast_update_module_list(int (*modentry)(char *module, char *description, int usecnt))
+{
+	struct module *m;
+	int unlock = -1;
+	if (pthread_mutex_trylock(&modlock))
+		unlock = 0;
+	m = module_list;
+	while(m) {
+		modentry(m->resource, m->description(), m->usecount());
+		m = m->next;
+	}
+	if (unlock)
+		pthread_mutex_unlock(&modlock);
+	return 0;
+}
+
+int ast_loader_register(int (*v)(void)) 
+{
+	struct loadupdate *tmp;
+	/* XXX Should be more flexible here, taking > 1 verboser XXX */
+	if ((tmp = malloc(sizeof (struct loadupdate)))) {
+		tmp->updater = v;
+		if (pthread_mutex_lock(&modlock))
+			ast_log(LOG_WARNING, "Failed to lock\n");
+		tmp->next = updaters;
+		updaters = tmp;
+		pthread_mutex_unlock(&modlock);
+		return 0;
+	}
+	return -1;
+}
+
+int ast_loader_unregister(int (*v)(void))
+{
+	int res = -1;
+	struct loadupdate *tmp, *tmpl=NULL;
+	if (pthread_mutex_lock(&modlock))
+		ast_log(LOG_WARNING, "Failed to lock\n");
+	tmp = updaters;
+	while(tmp) {
+		if (tmp->updater == v)	{
+			if (tmpl)
+				tmpl->next = tmp->next;
+			else
+				updaters = tmp->next;
+			break;
+		}
+		tmpl = tmp;
+		tmp = tmp->next;
+	}
+	if (tmp)
+		res = 0;
+	pthread_mutex_unlock(&modlock);
+	return res;
+}