qemu-patch-raspberry4/qom/object.c
Paolo Bonzini 11e35bfdc7 qom: use object_resolve_path_type for links
This allows to restrict partial matches to objects of the expected
type.  It will let people use bare names to reference drives
even though their name might be the same as a device's (e.g.
-drive id=hd0,if=none,... -device ...,drive=hd0,id=hd0).

As a useful byproduct, this fixes a problem with links of interface
type.  When a link property's type is an interface, the code expects
the implementation object (not the parent object) to be stored in the
variable.  The parent object does not contain the right vtable.

Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-02-07 13:52:41 +01:00

1105 lines
26 KiB
C

/*
* QEMU Object Model
*
* Copyright IBM, Corp. 2011
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/object.h"
#include "qemu-common.h"
#include "qapi/qapi-visit-core.h"
/* TODO: replace QObject with a simpler visitor to avoid a dependency
* of the QOM core on QObject? */
#include "qemu/qom-qobject.h"
#include "qobject.h"
#include "qbool.h"
#include "qint.h"
#include "qstring.h"
#define MAX_INTERFACES 32
typedef struct InterfaceImpl InterfaceImpl;
typedef struct TypeImpl TypeImpl;
struct InterfaceImpl
{
const char *parent;
void (*interface_initfn)(ObjectClass *class, void *data);
TypeImpl *type;
};
struct TypeImpl
{
const char *name;
size_t class_size;
size_t instance_size;
void (*class_init)(ObjectClass *klass, void *data);
void (*class_finalize)(ObjectClass *klass, void *data);
void *class_data;
void (*instance_init)(Object *obj);
void (*instance_finalize)(Object *obj);
bool abstract;
const char *parent;
TypeImpl *parent_type;
ObjectClass *class;
int num_interfaces;
InterfaceImpl interfaces[MAX_INTERFACES];
};
typedef struct Interface
{
Object parent;
Object *obj;
} Interface;
#define INTERFACE(obj) OBJECT_CHECK(Interface, obj, TYPE_INTERFACE)
static Type type_interface;
static GHashTable *type_table_get(void)
{
static GHashTable *type_table;
if (type_table == NULL) {
type_table = g_hash_table_new(g_str_hash, g_str_equal);
}
return type_table;
}
static void type_table_add(TypeImpl *ti)
{
g_hash_table_insert(type_table_get(), (void *)ti->name, ti);
}
static TypeImpl *type_table_lookup(const char *name)
{
return g_hash_table_lookup(type_table_get(), name);
}
TypeImpl *type_register(const TypeInfo *info)
{
TypeImpl *ti = g_malloc0(sizeof(*ti));
g_assert(info->name != NULL);
if (type_table_lookup(info->name) != NULL) {
fprintf(stderr, "Registering `%s' which already exists\n", info->name);
abort();
}
ti->name = g_strdup(info->name);
ti->parent = g_strdup(info->parent);
ti->class_size = info->class_size;
ti->instance_size = info->instance_size;
ti->class_init = info->class_init;
ti->class_finalize = info->class_finalize;
ti->class_data = info->class_data;
ti->instance_init = info->instance_init;
ti->instance_finalize = info->instance_finalize;
ti->abstract = info->abstract;
if (info->interfaces) {
int i;
for (i = 0; info->interfaces[i].type; i++) {
ti->interfaces[i].parent = info->interfaces[i].type;
ti->interfaces[i].interface_initfn = info->interfaces[i].interface_initfn;
ti->num_interfaces++;
}
}
type_table_add(ti);
return ti;
}
TypeImpl *type_register_static(const TypeInfo *info)
{
return type_register(info);
}
static TypeImpl *type_get_by_name(const char *name)
{
if (name == NULL) {
return NULL;
}
return type_table_lookup(name);
}
static TypeImpl *type_get_parent(TypeImpl *type)
{
if (!type->parent_type && type->parent) {
type->parent_type = type_get_by_name(type->parent);
g_assert(type->parent_type != NULL);
}
return type->parent_type;
}
static bool type_has_parent(TypeImpl *type)
{
return (type->parent != NULL);
}
static size_t type_class_get_size(TypeImpl *ti)
{
if (ti->class_size) {
return ti->class_size;
}
if (type_has_parent(ti)) {
return type_class_get_size(type_get_parent(ti));
}
return sizeof(ObjectClass);
}
static void type_class_interface_init(TypeImpl *ti, InterfaceImpl *iface)
{
TypeInfo info = {
.instance_size = sizeof(Interface),
.parent = iface->parent,
.class_size = sizeof(InterfaceClass),
.class_init = iface->interface_initfn,
.abstract = true,
};
char *name = g_strdup_printf("<%s::%s>", ti->name, iface->parent);
info.name = name;
iface->type = type_register(&info);
g_free(name);
}
static void type_class_init(TypeImpl *ti)
{
size_t class_size = sizeof(ObjectClass);
int i;
if (ti->class) {
return;
}
ti->class_size = type_class_get_size(ti);
ti->class = g_malloc0(ti->class_size);
ti->class->type = ti;
if (type_has_parent(ti)) {
TypeImpl *parent = type_get_parent(ti);
type_class_init(parent);
class_size = parent->class_size;
g_assert(parent->class_size <= ti->class_size);
memcpy((void *)ti->class + sizeof(ObjectClass),
(void *)parent->class + sizeof(ObjectClass),
parent->class_size - sizeof(ObjectClass));
}
memset((void *)ti->class + class_size, 0, ti->class_size - class_size);
for (i = 0; i < ti->num_interfaces; i++) {
type_class_interface_init(ti, &ti->interfaces[i]);
}
if (ti->class_init) {
ti->class_init(ti->class, ti->class_data);
}
}
static void object_interface_init(Object *obj, InterfaceImpl *iface)
{
TypeImpl *ti = iface->type;
Interface *iface_obj;
iface_obj = INTERFACE(object_new(ti->name));
iface_obj->obj = obj;
obj->interfaces = g_slist_prepend(obj->interfaces, iface_obj);
}
static void object_init_with_type(Object *obj, TypeImpl *ti)
{
int i;
if (type_has_parent(ti)) {
object_init_with_type(obj, type_get_parent(ti));
}
for (i = 0; i < ti->num_interfaces; i++) {
object_interface_init(obj, &ti->interfaces[i]);
}
if (ti->instance_init) {
ti->instance_init(obj);
}
}
void object_initialize_with_type(void *data, TypeImpl *type)
{
Object *obj = data;
g_assert(type != NULL);
g_assert(type->instance_size >= sizeof(ObjectClass));
type_class_init(type);
g_assert(type->abstract == false);
memset(obj, 0, type->instance_size);
obj->class = type->class;
QTAILQ_INIT(&obj->properties);
object_init_with_type(obj, type);
}
void object_initialize(void *data, const char *typename)
{
TypeImpl *type = type_get_by_name(typename);
object_initialize_with_type(data, type);
}
static void object_property_del_all(Object *obj)
{
while (!QTAILQ_EMPTY(&obj->properties)) {
ObjectProperty *prop = QTAILQ_FIRST(&obj->properties);
QTAILQ_REMOVE(&obj->properties, prop, node);
if (prop->release) {
prop->release(obj, prop->name, prop->opaque);
}
g_free(prop->name);
g_free(prop->type);
g_free(prop);
}
}
static void object_property_del_child(Object *obj, Object *child, Error **errp)
{
ObjectProperty *prop;
QTAILQ_FOREACH(prop, &obj->properties, node) {
if (!strstart(prop->type, "child<", NULL)) {
continue;
}
if (prop->opaque == child) {
object_property_del(obj, prop->name, errp);
}
}
}
void object_unparent(Object *obj)
{
if (obj->parent) {
object_property_del_child(obj->parent, obj, NULL);
}
}
static void object_deinit(Object *obj, TypeImpl *type)
{
if (type->instance_finalize) {
type->instance_finalize(obj);
}
while (obj->interfaces) {
Interface *iface_obj = obj->interfaces->data;
obj->interfaces = g_slist_delete_link(obj->interfaces, obj->interfaces);
object_delete(OBJECT(iface_obj));
}
if (type_has_parent(type)) {
object_deinit(obj, type_get_parent(type));
}
object_unparent(obj);
}
void object_finalize(void *data)
{
Object *obj = data;
TypeImpl *ti = obj->class->type;
object_deinit(obj, ti);
object_property_del_all(obj);
g_assert(obj->ref == 0);
}
Object *object_new_with_type(Type type)
{
Object *obj;
g_assert(type != NULL);
obj = g_malloc(type->instance_size);
object_initialize_with_type(obj, type);
object_ref(obj);
return obj;
}
Object *object_new(const char *typename)
{
TypeImpl *ti = type_get_by_name(typename);
return object_new_with_type(ti);
}
void object_delete(Object *obj)
{
object_unref(obj);
g_assert(obj->ref == 0);
g_free(obj);
}
static bool type_is_ancestor(TypeImpl *type, TypeImpl *target_type)
{
assert(target_type);
/* Check if typename is a direct ancestor of type */
while (type) {
if (type == target_type) {
return true;
}
type = type_get_parent(type);
}
return false;
}
static bool object_is_type(Object *obj, TypeImpl *target_type)
{
return !target_type || type_is_ancestor(obj->class->type, target_type);
}
Object *object_dynamic_cast(Object *obj, const char *typename)
{
TypeImpl *target_type = type_get_by_name(typename);
GSList *i;
/* Check if typename is a direct ancestor. Special-case TYPE_OBJECT,
* we want to go back from interfaces to the parent.
*/
if (target_type && object_is_type(obj, target_type)) {
return obj;
}
/* Check if obj is an interface and its containing object is a direct
* ancestor of typename. In principle we could do this test at the very
* beginning of object_dynamic_cast, avoiding a second call to
* object_is_type. However, casting between interfaces is relatively
* rare, and object_is_type(obj, type_interface) would fail almost always.
*
* Perhaps we could add a magic value to the object header for increased
* (run-time) type safety and to speed up tests like this one. If we ever
* do that we can revisit the order here.
*/
if (object_is_type(obj, type_interface)) {
assert(!obj->interfaces);
obj = INTERFACE(obj)->obj;
if (object_is_type(obj, target_type)) {
return obj;
}
}
if (!target_type) {
return obj;
}
/* Check if obj has an interface of typename */
for (i = obj->interfaces; i; i = i->next) {
Interface *iface = i->data;
if (object_is_type(OBJECT(iface), target_type)) {
return OBJECT(iface);
}
}
return NULL;
}
static void register_interface(void)
{
static TypeInfo interface_info = {
.name = TYPE_INTERFACE,
.instance_size = sizeof(Interface),
.abstract = true,
};
type_interface = type_register_static(&interface_info);
}
device_init(register_interface);
Object *object_dynamic_cast_assert(Object *obj, const char *typename)
{
Object *inst;
inst = object_dynamic_cast(obj, typename);
if (!inst) {
fprintf(stderr, "Object %p is not an instance of type %s\n",
obj, typename);
abort();
}
return inst;
}
ObjectClass *object_class_dynamic_cast(ObjectClass *class,
const char *typename)
{
TypeImpl *target_type = type_get_by_name(typename);
TypeImpl *type = class->type;
while (type) {
if (type == target_type) {
return class;
}
type = type_get_parent(type);
}
return NULL;
}
ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class,
const char *typename)
{
ObjectClass *ret = object_class_dynamic_cast(class, typename);
if (!ret) {
fprintf(stderr, "Object %p is not an instance of type %s\n",
class, typename);
abort();
}
return ret;
}
const char *object_get_typename(Object *obj)
{
return obj->class->type->name;
}
ObjectClass *object_get_class(Object *obj)
{
return obj->class;
}
const char *object_class_get_name(ObjectClass *klass)
{
return klass->type->name;
}
ObjectClass *object_class_by_name(const char *typename)
{
TypeImpl *type = type_get_by_name(typename);
if (!type) {
return NULL;
}
type_class_init(type);
return type->class;
}
typedef struct OCFData
{
void (*fn)(ObjectClass *klass, void *opaque);
const char *implements_type;
bool include_abstract;
void *opaque;
} OCFData;
static void object_class_foreach_tramp(gpointer key, gpointer value,
gpointer opaque)
{
OCFData *data = opaque;
TypeImpl *type = value;
ObjectClass *k;
type_class_init(type);
k = type->class;
if (!data->include_abstract && type->abstract) {
return;
}
if (data->implements_type &&
!object_class_dynamic_cast(k, data->implements_type)) {
return;
}
data->fn(k, data->opaque);
}
void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
const char *implements_type, bool include_abstract,
void *opaque)
{
OCFData data = { fn, implements_type, include_abstract, opaque };
g_hash_table_foreach(type_table_get(), object_class_foreach_tramp, &data);
}
void object_ref(Object *obj)
{
obj->ref++;
}
void object_unref(Object *obj)
{
g_assert(obj->ref > 0);
obj->ref--;
/* parent always holds a reference to its children */
if (obj->ref == 0) {
object_finalize(obj);
}
}
void object_property_add(Object *obj, const char *name, const char *type,
ObjectPropertyAccessor *get,
ObjectPropertyAccessor *set,
ObjectPropertyRelease *release,
void *opaque, Error **errp)
{
ObjectProperty *prop = g_malloc0(sizeof(*prop));
prop->name = g_strdup(name);
prop->type = g_strdup(type);
prop->get = get;
prop->set = set;
prop->release = release;
prop->opaque = opaque;
QTAILQ_INSERT_TAIL(&obj->properties, prop, node);
}
static ObjectProperty *object_property_find(Object *obj, const char *name)
{
ObjectProperty *prop;
QTAILQ_FOREACH(prop, &obj->properties, node) {
if (strcmp(prop->name, name) == 0) {
return prop;
}
}
return NULL;
}
void object_property_del(Object *obj, const char *name, Error **errp)
{
ObjectProperty *prop = object_property_find(obj, name);
QTAILQ_REMOVE(&obj->properties, prop, node);
prop->release(obj, prop->name, prop->opaque);
g_free(prop->name);
g_free(prop->type);
g_free(prop);
}
void object_property_get(Object *obj, Visitor *v, const char *name,
Error **errp)
{
ObjectProperty *prop = object_property_find(obj, name);
if (prop == NULL) {
error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
return;
}
if (!prop->get) {
error_set(errp, QERR_PERMISSION_DENIED);
} else {
prop->get(obj, v, prop->opaque, name, errp);
}
}
void object_property_set(Object *obj, Visitor *v, const char *name,
Error **errp)
{
ObjectProperty *prop = object_property_find(obj, name);
if (prop == NULL) {
error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
return;
}
if (!prop->set) {
error_set(errp, QERR_PERMISSION_DENIED);
} else {
prop->set(obj, v, prop->opaque, name, errp);
}
}
void object_property_set_str(Object *obj, const char *value,
const char *name, Error **errp)
{
QString *qstr = qstring_from_str(value);
object_property_set_qobject(obj, QOBJECT(qstr), name, errp);
QDECREF(qstr);
}
char *object_property_get_str(Object *obj, const char *name,
Error **errp)
{
QObject *ret = object_property_get_qobject(obj, name, errp);
QString *qstring;
char *retval;
if (!ret) {
return NULL;
}
qstring = qobject_to_qstring(ret);
if (!qstring) {
error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "string");
retval = NULL;
} else {
retval = g_strdup(qstring_get_str(qstring));
}
QDECREF(qstring);
return retval;
}
void object_property_set_bool(Object *obj, bool value,
const char *name, Error **errp)
{
QBool *qbool = qbool_from_int(value);
object_property_set_qobject(obj, QOBJECT(qbool), name, errp);
QDECREF(qbool);
}
bool object_property_get_bool(Object *obj, const char *name,
Error **errp)
{
QObject *ret = object_property_get_qobject(obj, name, errp);
QBool *qbool;
bool retval;
if (!ret) {
return false;
}
qbool = qobject_to_qbool(ret);
if (!qbool) {
error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "boolean");
retval = false;
} else {
retval = qbool_get_int(qbool);
}
QDECREF(qbool);
return retval;
}
void object_property_set_int(Object *obj, int64_t value,
const char *name, Error **errp)
{
QInt *qint = qint_from_int(value);
object_property_set_qobject(obj, QOBJECT(qint), name, errp);
QDECREF(qint);
}
int64_t object_property_get_int(Object *obj, const char *name,
Error **errp)
{
QObject *ret = object_property_get_qobject(obj, name, errp);
QInt *qint;
int64_t retval;
if (!ret) {
return -1;
}
qint = qobject_to_qint(ret);
if (!qint) {
error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "int");
retval = -1;
} else {
retval = qint_get_int(qint);
}
QDECREF(qint);
return retval;
}
const char *object_property_get_type(Object *obj, const char *name, Error **errp)
{
ObjectProperty *prop = object_property_find(obj, name);
if (prop == NULL) {
error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
return NULL;
}
return prop->type;
}
Object *object_get_root(void)
{
static Object *root;
if (!root) {
root = object_new("container");
}
return root;
}
static void object_get_child_property(Object *obj, Visitor *v, void *opaque,
const char *name, Error **errp)
{
Object *child = opaque;
gchar *path;
path = object_get_canonical_path(child);
visit_type_str(v, &path, name, errp);
g_free(path);
}
static void object_finalize_child_property(Object *obj, const char *name,
void *opaque)
{
Object *child = opaque;
object_unref(child);
}
void object_property_add_child(Object *obj, const char *name,
Object *child, Error **errp)
{
gchar *type;
type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
object_property_add(obj, name, type, object_get_child_property,
NULL, object_finalize_child_property, child, errp);
object_ref(child);
g_assert(child->parent == NULL);
child->parent = obj;
g_free(type);
}
static void object_get_link_property(Object *obj, Visitor *v, void *opaque,
const char *name, Error **errp)
{
Object **child = opaque;
gchar *path;
if (*child) {
path = object_get_canonical_path(*child);
visit_type_str(v, &path, name, errp);
g_free(path);
} else {
path = (gchar *)"";
visit_type_str(v, &path, name, errp);
}
}
static void object_set_link_property(Object *obj, Visitor *v, void *opaque,
const char *name, Error **errp)
{
Object **child = opaque;
bool ambiguous = false;
const char *type;
char *path;
gchar *target_type;
type = object_property_get_type(obj, name, NULL);
visit_type_str(v, &path, name, errp);
if (*child) {
object_unref(*child);
*child = NULL;
}
if (strcmp(path, "") != 0) {
Object *target;
/* Go from link<FOO> to FOO. */
target_type = g_strndup(&type[5], strlen(type) - 6);
target = object_resolve_path_type(path, target_type, &ambiguous);
if (ambiguous) {
error_set(errp, QERR_AMBIGUOUS_PATH, path);
} else if (target) {
object_ref(target);
*child = target;
} else {
target = object_resolve_path(path, &ambiguous);
if (target || ambiguous) {
error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, target_type);
} else {
error_set(errp, QERR_DEVICE_NOT_FOUND, path);
}
}
g_free(target_type);
}
g_free(path);
}
void object_property_add_link(Object *obj, const char *name,
const char *type, Object **child,
Error **errp)
{
gchar *full_type;
full_type = g_strdup_printf("link<%s>", type);
object_property_add(obj, name, full_type,
object_get_link_property,
object_set_link_property,
NULL, child, errp);
g_free(full_type);
}
gchar *object_get_canonical_path(Object *obj)
{
Object *root = object_get_root();
char *newpath = NULL, *path = NULL;
while (obj != root) {
ObjectProperty *prop = NULL;
g_assert(obj->parent != NULL);
QTAILQ_FOREACH(prop, &obj->parent->properties, node) {
if (!strstart(prop->type, "child<", NULL)) {
continue;
}
if (prop->opaque == obj) {
if (path) {
newpath = g_strdup_printf("%s/%s", prop->name, path);
g_free(path);
path = newpath;
} else {
path = g_strdup(prop->name);
}
break;
}
}
g_assert(prop != NULL);
obj = obj->parent;
}
newpath = g_strdup_printf("/%s", path);
g_free(path);
return newpath;
}
static Object *object_resolve_abs_path(Object *parent,
gchar **parts,
const char *typename,
int index)
{
ObjectProperty *prop;
Object *child;
if (parts[index] == NULL) {
return object_dynamic_cast(parent, typename);
}
if (strcmp(parts[index], "") == 0) {
return object_resolve_abs_path(parent, parts, typename, index + 1);
}
prop = object_property_find(parent, parts[index]);
if (prop == NULL) {
return NULL;
}
child = NULL;
if (strstart(prop->type, "link<", NULL)) {
Object **pchild = prop->opaque;
if (*pchild) {
child = *pchild;
}
} else if (strstart(prop->type, "child<", NULL)) {
child = prop->opaque;
}
if (!child) {
return NULL;
}
return object_resolve_abs_path(child, parts, typename, index + 1);
}
static Object *object_resolve_partial_path(Object *parent,
gchar **parts,
const char *typename,
bool *ambiguous)
{
Object *obj;
ObjectProperty *prop;
obj = object_resolve_abs_path(parent, parts, typename, 0);
QTAILQ_FOREACH(prop, &parent->properties, node) {
Object *found;
if (!strstart(prop->type, "child<", NULL)) {
continue;
}
found = object_resolve_partial_path(prop->opaque, parts,
typename, ambiguous);
if (found) {
if (obj) {
if (ambiguous) {
*ambiguous = true;
}
return NULL;
}
obj = found;
}
if (ambiguous && *ambiguous) {
return NULL;
}
}
return obj;
}
Object *object_resolve_path_type(const char *path, const char *typename,
bool *ambiguous)
{
bool partial_path = true;
Object *obj;
gchar **parts;
parts = g_strsplit(path, "/", 0);
if (parts == NULL || parts[0] == NULL) {
g_strfreev(parts);
return object_get_root();
}
if (strcmp(parts[0], "") == 0) {
partial_path = false;
}
if (partial_path) {
if (ambiguous) {
*ambiguous = false;
}
obj = object_resolve_partial_path(object_get_root(), parts,
typename, ambiguous);
} else {
obj = object_resolve_abs_path(object_get_root(), parts, typename, 1);
}
g_strfreev(parts);
return obj;
}
Object *object_resolve_path(const char *path, bool *ambiguous)
{
return object_resolve_path_type(path, TYPE_OBJECT, ambiguous);
}
typedef struct StringProperty
{
char *(*get)(Object *, Error **);
void (*set)(Object *, const char *, Error **);
} StringProperty;
static void property_get_str(Object *obj, Visitor *v, void *opaque,
const char *name, Error **errp)
{
StringProperty *prop = opaque;
char *value;
value = prop->get(obj, errp);
if (value) {
visit_type_str(v, &value, name, errp);
g_free(value);
}
}
static void property_set_str(Object *obj, Visitor *v, void *opaque,
const char *name, Error **errp)
{
StringProperty *prop = opaque;
char *value;
Error *local_err = NULL;
visit_type_str(v, &value, name, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
prop->set(obj, value, errp);
g_free(value);
}
static void property_release_str(Object *obj, const char *name,
void *opaque)
{
StringProperty *prop = opaque;
g_free(prop);
}
void object_property_add_str(Object *obj, const char *name,
char *(*get)(Object *, Error **),
void (*set)(Object *, const char *, Error **),
Error **errp)
{
StringProperty *prop = g_malloc0(sizeof(*prop));
prop->get = get;
prop->set = set;
object_property_add(obj, name, "string",
get ? property_get_str : NULL,
set ? property_set_str : NULL,
property_release_str,
prop, errp);
}