/*
* QEMU Module Infrastructure
*
* Copyright IBM, Corp. 2009
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu/osdep.h"
#ifdef CONFIG_MODULES
#include <gmodule.h>
#endif
#include "qemu/queue.h"
#include "qemu/module.h"
#include "qemu/cutils.h"
#include "qemu/config-file.h"
#include "qapi/error.h"
#ifdef CONFIG_MODULE_UPGRADES
#include "qemu-version.h"
#endif
#include "trace.h"
typedef struct ModuleEntry
{
void (*init)(void);
QTAILQ_ENTRY(ModuleEntry) node;
module_init_type type;
} ModuleEntry;
typedef QTAILQ_HEAD(, ModuleEntry) ModuleTypeList;
static ModuleTypeList init_type_list[MODULE_INIT_MAX];
static bool modules_init_done[MODULE_INIT_MAX];
static ModuleTypeList dso_init_list;
static void init_lists(void)
{
static int inited;
int i;
if (inited) {
return;
}
for (i = 0; i < MODULE_INIT_MAX; i++) {
QTAILQ_INIT(&init_type_list[i]);
}
QTAILQ_INIT(&dso_init_list);
inited = 1;
}
static ModuleTypeList *find_type(module_init_type type)
{
init_lists();
return &init_type_list[type];
}
void register_module_init(void (*fn)(void), module_init_type type)
{
ModuleEntry *e;
ModuleTypeList *l;
e = g_malloc0(sizeof(*e));
e->init = fn;
e->type = type;
l = find_type(type);
QTAILQ_INSERT_TAIL(l, e, node);
}
void register_dso_module_init(void (*fn)(void), module_init_type type)
{
ModuleEntry *e;
init_lists();
e = g_malloc0(sizeof(*e));
e->init = fn;
e->type = type;
QTAILQ_INSERT_TAIL(&dso_init_list, e, node);
}
void module_call_init(module_init_type type)
{
ModuleTypeList *l;
ModuleEntry *e;
if (modules_init_done[type]) {
return;
}
l = find_type(type);
QTAILQ_FOREACH(e, l, node) {
e->init();
}
modules_init_done[type] = true;
}
#ifdef CONFIG_MODULES
static const QemuModinfo module_info_stub[] = { {
/* end of list */
} };
static const QemuModinfo *module_info = module_info_stub;
static const char *module_arch;
void module_init_info(const QemuModinfo *info)
{
module_info = info;
}
void module_allow_arch(const char *arch)
{
module_arch = arch;
}
static bool module_check_arch(const QemuModinfo *modinfo)
{
if (modinfo->arch) {
if (!module_arch) {
/* no arch set -> ignore all */
return false;
}
if (strcmp(module_arch, modinfo->arch) != 0) {
/* mismatch */
return false;
}
}
return true;
}
/*
* module_load_dso: attempt to load an existing dso file
*
* fname: full pathname of the file to load
* export_symbols: if true, add the symbols to the global name space
* errp: error to set.
*
* Return value: true on success, false on error, and errp will be set.
*/
static bool module_load_dso(const char *fname, bool export_symbols,
Error **errp)
{
GModule *g_module;
void (*sym)(void);
ModuleEntry *e, *next;
int flags;
assert(QTAILQ_EMPTY(&dso_init_list));
flags = 0;
if (!export_symbols) {
flags |= G_MODULE_BIND_LOCAL;
}
g_module = g_module_open(fname, flags);
if (!g_module) {
error_setg(errp, "failed to open module: %s", g_module_error());
return false;
}
if (!g_module_symbol(g_module, DSO_STAMP_FUN_STR, (gpointer *)&sym)) {
error_setg(errp, "failed to initialize module: %s", fname);
/*
* Print some info if this is a QEMU module (but from different build),
* this will make debugging user problems easier.
*/
if (g_module_symbol(g_module, "qemu_module_dummy", (gpointer *)&sym)) {
error_append_hint(errp,
"Only modules from the same build can be loaded.\n");
}
g_module_close(g_module);
return false;
}
QTAILQ_FOREACH(e, &dso_init_list, node) {
e->init();
register_module_init(e->init, e->type);
}
trace_module_load_module(fname);
QTAILQ_FOREACH_SAFE(e, &dso_init_list, node, next) {
QTAILQ_REMOVE(&dso_init_list, e, node);
g_free(e);
}
return true;
}
int module_load(const char *prefix, const char *name, Error **errp)
{
int rv = -1;
#ifdef CONFIG_MODULE_UPGRADES
char *version_dir;
#endif
const char *search_dir;
char *dirs[5];
char *module_name;
int i = 0, n_dirs = 0;
bool export_symbols = false;
static GHashTable *loaded_modules;
const QemuModinfo *modinfo;
const char **sl;
if (!g_module_supported()) {
error_setg(errp, "%s", "this platform does not support GLib modules");
return -1;
}
if (!loaded_modules) {
loaded_modules = g_hash_table_new(g_str_hash, g_str_equal);
}
/* allocate all resources managed by the out: label here */
module_name = g_strdup_printf("%s%s", prefix, name);
if (g_hash_table_contains(loaded_modules, module_name)) {
g_free(module_name);
return 2; /* module already loaded */
}
g_hash_table_add(loaded_modules, module_name);
search_dir = getenv("QEMU_MODULE_DIR");
if (search_dir != NULL) {
dirs[n_dirs++] = g_strdup_printf("%s", search_dir);
}
dirs[n_dirs++] = get_relocated_path(CONFIG_QEMU_MODDIR);
#ifdef CONFIG_MODULE_UPGRADES
version_dir = g_strcanon(g_strdup(QEMU_PKGVERSION),
G_CSET_A_2_Z G_CSET_a_2_z G_CSET_DIGITS "+-.~",
'_');
dirs[n_dirs++] = g_strdup_printf("/var/run/qemu/%s", version_dir);
#endif
assert(n_dirs <= ARRAY_SIZE(dirs));
/* end of resources managed by the out: label */
for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
if (modinfo->arch) {
if (strcmp(modinfo->name, module_name) == 0) {
if (!module_check_arch(modinfo)) {
error_setg(errp, "module arch does not match: "
"expected '%s', got '%s'", module_arch, modinfo->arch);
goto out;
}
}
}
if (modinfo->deps) {
if (strcmp(modinfo->name, module_name) == 0) {
/* we depend on other module(s) */
for (sl = modinfo->deps; *sl != NULL; sl++) {
int subrv = module_load("", *sl, errp);
if (subrv <= 0) {
rv = subrv;
goto out;
}
}
} else {
for (sl = modinfo->deps; *sl != NULL; sl++) {
if (strcmp(module_name, *sl) == 0) {
/* another module depends on us */
export_symbols = true;
}
}
}
}
}
for (i = 0; i < n_dirs; i++) {
char *fname = g_strdup_printf("%s/%s%s",
dirs[i], module_name, CONFIG_HOST_DSOSUF);
int ret = access(fname, F_OK);
if (ret != 0 && (errno == ENOENT || errno == ENOTDIR)) {
/*
* if we don't find the module in this dir, try the next one.
* If we don't find it in any dir, that can be fine too: user
* did not install the module. We will return 0 in this case
* with no error set.
*/
g_free(fname);
continue;
} else if (ret != 0) {
/* most common is EACCES here */
error_setg_errno(errp, errno, "error trying to access %s", fname);
} else if (module_load_dso(fname, export_symbols, errp)) {
rv = 1; /* module successfully loaded */
}
g_free(fname);
goto out;
}
rv = 0; /* module not found */
out:
if (rv <= 0) {
g_hash_table_remove(loaded_modules, module_name);
g_free(module_name);
}
for (i = 0; i < n_dirs; i++) {
g_free(dirs[i]);
}
return rv;
}
static bool module_loaded_qom_all;
int module_load_qom(const char *type, Error **errp)
{
const QemuModinfo *modinfo;
const char **sl;
int rv = 0;
if (!type) {
error_setg(errp, "%s", "type is NULL");
return -1;
}
trace_module_lookup_object_type(type);
for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
if (!modinfo->objs) {
continue;
}
if (!module_check_arch(modinfo)) {
continue;
}
for (sl = modinfo->objs; *sl != NULL; sl++) {
if (strcmp(type, *sl) == 0) {
if (rv > 0) {
error_setg(errp, "multiple modules providing '%s'", type);
return -1;
}
rv = module_load("", modinfo->name, errp);
if (rv < 0) {
return rv;
}
}
}
}
return rv;
}
void module_load_qom_all(void)
{
const QemuModinfo *modinfo;
Error *local_err = NULL;
if (module_loaded_qom_all) {
return;
}
for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
if (!modinfo->objs) {
continue;
}
if (!module_check_arch(modinfo)) {
continue;
}
if (module_load("", modinfo->name, &local_err) < 0) {
error_report_err(local_err);
}
}
module_loaded_qom_all = true;
}
void qemu_load_module_for_opts(const char *group)
{
const QemuModinfo *modinfo;
const char **sl;
for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
if (!modinfo->opts) {
continue;
}
for (sl = modinfo->opts; *sl != NULL; sl++) {
if (strcmp(group, *sl) == 0) {
Error *local_err = NULL;
if (module_load("", modinfo->name, &local_err) < 0) {
error_report_err(local_err);
}
}
}
}
}
#else
void module_allow_arch(const char *arch) {}
void qemu_load_module_for_opts(const char *group) {}
int module_load(const char *prefix, const char *name, Error **errp) { return 2; }
int module_load_qom(const char *type, Error **errp) { return 2; }
void module_load_qom_all(void) {}
#endif
