/* * driver.c: Helpers for loading drivers * * Copyright (C) 2006-2011 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library. If not, see * . * */ #include #include #include "driver.h" #include "viralloc.h" #include "virfile.h" #include "virlog.h" #include "configmake.h" VIR_LOG_INIT("driver"); /* XXX re-implement this for other OS, or use libtools helper lib ? */ #include #define DEFAULT_DRIVER_DIR LIBDIR "/libvirt/connection-driver" static void * virDriverLoadModuleFile(const char *file) { void *handle = NULL; VIR_DEBUG("Load module file '%s'", file); if (access(file, R_OK) < 0) { VIR_INFO("Module %s not accessible", file); return NULL; } virUpdateSelfLastChanged(file); if (!(handle = dlopen(file, RTLD_NOW | RTLD_GLOBAL))) VIR_ERROR(_("failed to load module %s %s"), file, dlerror()); return handle; } static void * virDriverLoadModuleFunc(void *handle, const char *funcname) { void *regsym; VIR_DEBUG("Lookup function '%s'", funcname); if (!(regsym = dlsym(handle, funcname))) VIR_ERROR(_("Missing module registration symbol %s"), funcname); return regsym; } /** * virDriverLoadModuleFull: * @path: filename of module to load * @regfunc: name of the function that registers the module * @handle: Returns handle of the loaded library if not NULL * * Loads a loadable module named @path and calls the * registration function @regfunc. If @handle is not NULL the handle is returned * in the variable. Otherwise the handle is leaked so that the module stays * loaded forever. * * The module is automatically looked up in the appropriate place (git or * installed directory). * * Returns 0 on success, 1 if the module was not found and -1 on any error. */ int virDriverLoadModuleFull(const char *path, const char *regfunc, void **handle) { void *rethandle = NULL; int (*regsym)(void); int ret = -1; if (!(rethandle = virDriverLoadModuleFile(path))) { ret = 1; goto cleanup; } if (!(regsym = virDriverLoadModuleFunc(rethandle, regfunc))) goto cleanup; if ((*regsym)() < 0) { VIR_ERROR(_("Failed module registration %s"), regfunc); goto cleanup; } if (handle) VIR_STEAL_PTR(*handle, rethandle); else rethandle = NULL; ret = 0; cleanup: if (rethandle) dlclose(rethandle); return ret; } int virDriverLoadModule(const char *name, const char *regfunc) { char *modfile = NULL; int ret; VIR_DEBUG("Module load %s", name); if (!(modfile = virFileFindResourceFull(name, "libvirt_driver_", ".so", abs_topbuilddir "/src/.libs", DEFAULT_DRIVER_DIR, "LIBVIRT_DRIVER_DIR"))) return 1; ret = virDriverLoadModuleFull(modfile, regfunc, NULL); VIR_FREE(modfile); return ret; } /* XXX unload modules, but we can't until we can unregister libvirt drivers */