qemu/qom/object_interfaces.c

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#include "qemu/osdep.h"
#include "qemu/cutils.h"
2016-03-14 11:01:28 +03:00
#include "qapi/error.h"
#include "qapi/qapi-visit-qom.h"
#include "qapi/qmp/qobject.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qerror.h"
#include "qapi/qmp/qjson.h"
#include "qapi/qobject-input-visitor.h"
#include "qapi/qobject-output-visitor.h"
#include "qom/object_interfaces.h"
#include "qemu/help_option.h"
#include "qemu/id.h"
#include "qemu/module.h"
#include "qemu/option.h"
#include "qemu/qemu-print.h"
#include "qapi/opts-visitor.h"
monitor: fix object_del for command-line-created objects Currently objects specified on the command-line are only partially cleaned up when 'object_del' is issued in either HMP or QMP: the object itself is fully finalized, but the QemuOpts are not removed. This results in the following behavior: x86_64-softmmu/qemu-system-x86_64 -monitor stdio \ -object memory-backend-ram,id=ram1,size=256M QEMU 2.7.91 monitor - type 'help' for more information (qemu) object_del ram1 (qemu) object_del ram1 object 'ram1' not found (qemu) object_add memory-backend-ram,id=ram1,size=256M Duplicate ID 'ram1' for object Try "help object_add" for more information which can be an issue for use-cases like memory hotplug. This happens on the HMP side because hmp_object_add() attempts to create a temporary QemuOpts entry with ID 'ram1', which ends up conflicting with the command-line-created entry, since it was never cleaned up during the previous hmp_object_del() call. We address this by adding a check in user_creatable_del(), which is called by both qmp_object_del() and hmp_object_del() to handle the actual object cleanup, to determine whether an option group entry matching the object's ID is present and removing it if it is. Note that qmp_object_add() never attempts to create a temporary QemuOpts entry, so it does not encounter the duplicate ID error, which is why this isn't generally visible in libvirt. Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Markus Armbruster <armbru@redhat.com> Cc: Eric Blake <eblake@redhat.com> Cc: Daniel Berrange <berrange@redhat.com> Cc: qemu-stable@nongnu.org Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1496531612-22166-3-git-send-email-mdroth@linux.vnet.ibm.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-06-04 02:13:32 +03:00
#include "qemu/config-file.h"
#include "qemu/keyval.h"
bool user_creatable_complete(UserCreatable *uc, Error **errp)
{
UserCreatableClass *ucc = USER_CREATABLE_GET_CLASS(uc);
Error *err = NULL;
if (ucc->complete) {
ucc->complete(uc, &err);
error_propagate(errp, err);
}
return !err;
}
bool user_creatable_can_be_deleted(UserCreatable *uc)
{
UserCreatableClass *ucc = USER_CREATABLE_GET_CLASS(uc);
if (ucc->can_be_deleted) {
return ucc->can_be_deleted(uc);
} else {
return true;
}
}
static void object_set_properties_from_qdict(Object *obj, const QDict *qdict,
Visitor *v, Error **errp)
{
const QDictEntry *e;
if (!visit_start_struct(v, NULL, NULL, 0, errp)) {
return;
}
for (e = qdict_first(qdict); e; e = qdict_next(qdict, e)) {
if (!object_property_set(obj, e->key, v, errp)) {
goto out;
}
}
visit_check_struct(v, errp);
out:
visit_end_struct(v, NULL);
}
void object_set_properties_from_keyval(Object *obj, const QDict *qdict,
bool from_json, Error **errp)
{
Visitor *v;
if (from_json) {
v = qobject_input_visitor_new(QOBJECT(qdict));
} else {
v = qobject_input_visitor_new_keyval(QOBJECT(qdict));
}
object_set_properties_from_qdict(obj, qdict, v, errp);
visit_free(v);
}
Object *user_creatable_add_type(const char *type, const char *id,
const QDict *qdict,
Visitor *v, Error **errp)
{
ERRP_GUARD();
Object *obj;
ObjectClass *klass;
Error *local_err = NULL;
if (id != NULL && !id_wellformed(id)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id", "an identifier");
error_append_hint(errp, "Identifiers consist of letters, digits, "
"'-', '.', '_', starting with a letter.\n");
return NULL;
}
klass = object_class_by_name(type);
if (!klass) {
error_setg(errp, "invalid object type: %s", type);
return NULL;
}
if (!object_class_dynamic_cast(klass, TYPE_USER_CREATABLE)) {
error_setg(errp, "object type '%s' isn't supported by object-add",
type);
return NULL;
}
if (object_class_is_abstract(klass)) {
error_setg(errp, "object type '%s' is abstract", type);
return NULL;
}
qom: Wrap prop visit in visit_start_struct The qmp-input visitor was allowing callers to play rather fast and loose: when visiting a QDict, you could grab members of the root dictionary without first pushing into the dict; the final such culprit was the QOM code for converting to and from object properties. But we are about to tighten the input visitor, at which point user_creatable_add_type() as called with a QMP input visitor via qmp_object_add() MUST follow the same paradigms as everyone else, of pushing into the struct before grabbing its keys. The use of 'err ? NULL : &err' is temporary; a later patch will clean that up when it splits visit_end_struct(). Furthermore, note that both callers always pass qdict, so we can convert the conditional into an assert and reduce indentation. The change has no impact to the testsuite now, but is required to avoid a failure in tests/test-netfilter once qmp-input is made stricter to detect inconsistent 'name' arguments on the root visit. Since user_creatable_add_type() is also called with OptsVisitor through user_creatable_add_opts(), we must also check that there is no negative impact there; both pre- and post-patch, we see: $ ./x86_64-softmmu/qemu-system-x86_64 -nographic -nodefaults -qmp stdio -object secret,id=sec0,data=letmein,format=raw,foo=bar qemu-system-x86_64: -object secret,id=sec0,data=letmein,format=raw,foo=bar: Property '.foo' not found That is, the only new checking that the new visit_end_struct() can perform is for excess input, but we already catch excess input earlier in object_property_set(). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1461879932-9020-10-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-04-29 00:45:17 +03:00
assert(qdict);
obj = object_new(type);
object_set_properties_from_qdict(obj, qdict, v, &local_err);
qom: Wrap prop visit in visit_start_struct The qmp-input visitor was allowing callers to play rather fast and loose: when visiting a QDict, you could grab members of the root dictionary without first pushing into the dict; the final such culprit was the QOM code for converting to and from object properties. But we are about to tighten the input visitor, at which point user_creatable_add_type() as called with a QMP input visitor via qmp_object_add() MUST follow the same paradigms as everyone else, of pushing into the struct before grabbing its keys. The use of 'err ? NULL : &err' is temporary; a later patch will clean that up when it splits visit_end_struct(). Furthermore, note that both callers always pass qdict, so we can convert the conditional into an assert and reduce indentation. The change has no impact to the testsuite now, but is required to avoid a failure in tests/test-netfilter once qmp-input is made stricter to detect inconsistent 'name' arguments on the root visit. Since user_creatable_add_type() is also called with OptsVisitor through user_creatable_add_opts(), we must also check that there is no negative impact there; both pre- and post-patch, we see: $ ./x86_64-softmmu/qemu-system-x86_64 -nographic -nodefaults -qmp stdio -object secret,id=sec0,data=letmein,format=raw,foo=bar qemu-system-x86_64: -object secret,id=sec0,data=letmein,format=raw,foo=bar: Property '.foo' not found That is, the only new checking that the new visit_end_struct() can perform is for excess input, but we already catch excess input earlier in object_property_set(). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1461879932-9020-10-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-04-29 00:45:17 +03:00
if (local_err) {
goto out;
}
if (id != NULL) {
qom: Introduce object_property_try_add_child() object_property_add() does not allow object_property_try_add() to gracefully fail as &error_abort is passed as an error handle. However such failure can easily be triggered from the QMP shell when, for instance, one attempts to create an object with an id that already exists. This is achieved from the following call path: qmp_object_add -> user_creatable_add_dict -> user_creatable_add_type -> object_property_add_child -> object_property_add For instance, from the qmp-shell, call twice: object-add qom-type=memory-backend-ram id=mem1 props.size=1073741824 and QEMU aborts. This behavior is undesired as a user/management application mistake in reusing a property ID shouldn't result in loss of the VM and live data within. This patch introduces a new function, object_property_try_add_child() which takes an error handle and turn object_property_try_add() into a non-static one. Now the call path becomes: user_creatable_add_type -> object_property_try_add_child -> object_property_try_add and the error is returned gracefully to the QMP client. (QEMU) object-add qom-type=memory-backend-ram id=mem2 props.size=4294967296 {"return": {}} (QEMU) object-add qom-type=memory-backend-ram id=mem2 props.size=4294967296 {"error": {"class": "GenericError", "desc": "attempt to add duplicate property 'mem2' to object (type 'container')"}} Signed-off-by: Eric Auger <eric.auger@redhat.com> Fixes: d2623129a7de ("qom: Drop parameter @errp of object_property_add() & friends") Reviewed-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Greg Kurz <groug@kaod.org> Tested-by: Greg Kurz <groug@kaod.org> Message-Id: <20200629193424.30280-2-eric.auger@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-29 22:34:22 +03:00
object_property_try_add_child(object_get_objects_root(),
id, obj, &local_err);
if (local_err) {
goto out;
}
}
if (!user_creatable_complete(USER_CREATABLE(obj), &local_err)) {
if (id != NULL) {
object_property_del(object_get_objects_root(), id);
}
goto out;
}
out:
if (local_err) {
error_propagate(errp, local_err);
object_unref(obj);
return NULL;
}
return obj;
}
void user_creatable_add_qapi(ObjectOptions *options, Error **errp)
{
Visitor *v;
QObject *qobj;
QDict *props;
Object *obj;
v = qobject_output_visitor_new(&qobj);
visit_type_ObjectOptions(v, NULL, &options, &error_abort);
visit_complete(v, &qobj);
visit_free(v);
props = qobject_to(QDict, qobj);
qdict_del(props, "qom-type");
qdict_del(props, "id");
v = qobject_input_visitor_new(QOBJECT(props));
obj = user_creatable_add_type(ObjectType_str(options->qom_type),
options->id, props, v, errp);
object_unref(obj);
qobject_unref(qobj);
visit_free(v);
}
char *object_property_help(const char *name, const char *type,
QObject *defval, const char *description)
{
GString *str = g_string_new(NULL);
g_string_append_printf(str, " %s=<%s>", name, type);
if (description || defval) {
if (str->len < 24) {
g_string_append_printf(str, "%*s", 24 - (int)str->len, "");
}
g_string_append(str, " - ");
}
if (description) {
g_string_append(str, description);
}
if (defval) {
g_autofree char *def_json = g_string_free(qobject_to_json(defval),
false);
g_string_append_printf(str, " (default: %s)", def_json);
}
return g_string_free(str, false);
}
static void user_creatable_print_types(void)
{
GSList *l, *list;
qemu_printf("List of user creatable objects:\n");
list = object_class_get_list_sorted(TYPE_USER_CREATABLE, false);
for (l = list; l != NULL; l = l->next) {
ObjectClass *oc = OBJECT_CLASS(l->data);
qemu_printf(" %s\n", object_class_get_name(oc));
}
g_slist_free(list);
}
bool type_print_class_properties(const char *type)
{
ObjectClass *klass;
ObjectPropertyIterator iter;
ObjectProperty *prop;
GPtrArray *array;
int i;
klass = object_class_by_name(type);
if (!klass) {
return false;
}
array = g_ptr_array_new();
object_class_property_iter_init(&iter, klass);
while ((prop = object_property_iter_next(&iter))) {
if (!prop->set) {
continue;
}
g_ptr_array_add(array,
object_property_help(prop->name, prop->type,
prop->defval, prop->description));
}
g_ptr_array_sort(array, (GCompareFunc)qemu_pstrcmp0);
if (array->len > 0) {
qemu_printf("%s options:\n", type);
} else {
qemu_printf("There are no options for %s.\n", type);
}
for (i = 0; i < array->len; i++) {
qemu_printf("%s\n", (char *)array->pdata[i]);
}
g_ptr_array_set_free_func(array, g_free);
g_ptr_array_free(array, true);
return true;
}
bool user_creatable_print_help(const char *type, QemuOpts *opts)
{
if (is_help_option(type)) {
user_creatable_print_types();
return true;
}
if (qemu_opt_has_help_opt(opts)) {
return type_print_class_properties(type);
}
return false;
}
static void user_creatable_print_help_from_qdict(QDict *args)
{
const char *type = qdict_get_try_str(args, "qom-type");
if (!type || !type_print_class_properties(type)) {
user_creatable_print_types();
}
}
ObjectOptions *user_creatable_parse_str(const char *str, Error **errp)
{
ERRP_GUARD();
QObject *obj;
bool help;
Visitor *v;
ObjectOptions *options;
if (str[0] == '{') {
obj = qobject_from_json(str, errp);
if (!obj) {
return NULL;
}
v = qobject_input_visitor_new(obj);
} else {
QDict *args = keyval_parse(str, "qom-type", &help, errp);
if (*errp) {
return NULL;
}
if (help) {
user_creatable_print_help_from_qdict(args);
qobject_unref(args);
return NULL;
}
obj = QOBJECT(args);
v = qobject_input_visitor_new_keyval(obj);
}
visit_type_ObjectOptions(v, NULL, &options, errp);
visit_free(v);
qobject_unref(obj);
return options;
}
bool user_creatable_add_from_str(const char *str, Error **errp)
{
ERRP_GUARD();
ObjectOptions *options;
options = user_creatable_parse_str(str, errp);
if (!options) {
return false;
}
user_creatable_add_qapi(options, errp);
qapi_free_ObjectOptions(options);
return !*errp;
}
void user_creatable_process_cmdline(const char *cmdline)
{
if (!user_creatable_add_from_str(cmdline, &error_fatal)) {
/* Help was printed */
exit(EXIT_SUCCESS);
}
}
bool user_creatable_del(const char *id, Error **errp)
{
QemuOptsList *opts_list;
Object *container;
Object *obj;
container = object_get_objects_root();
obj = object_resolve_path_component(container, id);
if (!obj) {
error_setg(errp, "object '%s' not found", id);
return false;
}
if (!user_creatable_can_be_deleted(USER_CREATABLE(obj))) {
error_setg(errp, "object '%s' is in use, can not be deleted", id);
return false;
}
monitor: fix object_del for command-line-created objects Currently objects specified on the command-line are only partially cleaned up when 'object_del' is issued in either HMP or QMP: the object itself is fully finalized, but the QemuOpts are not removed. This results in the following behavior: x86_64-softmmu/qemu-system-x86_64 -monitor stdio \ -object memory-backend-ram,id=ram1,size=256M QEMU 2.7.91 monitor - type 'help' for more information (qemu) object_del ram1 (qemu) object_del ram1 object 'ram1' not found (qemu) object_add memory-backend-ram,id=ram1,size=256M Duplicate ID 'ram1' for object Try "help object_add" for more information which can be an issue for use-cases like memory hotplug. This happens on the HMP side because hmp_object_add() attempts to create a temporary QemuOpts entry with ID 'ram1', which ends up conflicting with the command-line-created entry, since it was never cleaned up during the previous hmp_object_del() call. We address this by adding a check in user_creatable_del(), which is called by both qmp_object_del() and hmp_object_del() to handle the actual object cleanup, to determine whether an option group entry matching the object's ID is present and removing it if it is. Note that qmp_object_add() never attempts to create a temporary QemuOpts entry, so it does not encounter the duplicate ID error, which is why this isn't generally visible in libvirt. Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Markus Armbruster <armbru@redhat.com> Cc: Eric Blake <eblake@redhat.com> Cc: Daniel Berrange <berrange@redhat.com> Cc: qemu-stable@nongnu.org Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1496531612-22166-3-git-send-email-mdroth@linux.vnet.ibm.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-06-04 02:13:32 +03:00
/*
* if object was defined on the command-line, remove its corresponding
* option group entry
*/
opts_list = qemu_find_opts_err("object", NULL);
if (opts_list) {
qemu_opts_del(qemu_opts_find(opts_list, id));
}
monitor: fix object_del for command-line-created objects Currently objects specified on the command-line are only partially cleaned up when 'object_del' is issued in either HMP or QMP: the object itself is fully finalized, but the QemuOpts are not removed. This results in the following behavior: x86_64-softmmu/qemu-system-x86_64 -monitor stdio \ -object memory-backend-ram,id=ram1,size=256M QEMU 2.7.91 monitor - type 'help' for more information (qemu) object_del ram1 (qemu) object_del ram1 object 'ram1' not found (qemu) object_add memory-backend-ram,id=ram1,size=256M Duplicate ID 'ram1' for object Try "help object_add" for more information which can be an issue for use-cases like memory hotplug. This happens on the HMP side because hmp_object_add() attempts to create a temporary QemuOpts entry with ID 'ram1', which ends up conflicting with the command-line-created entry, since it was never cleaned up during the previous hmp_object_del() call. We address this by adding a check in user_creatable_del(), which is called by both qmp_object_del() and hmp_object_del() to handle the actual object cleanup, to determine whether an option group entry matching the object's ID is present and removing it if it is. Note that qmp_object_add() never attempts to create a temporary QemuOpts entry, so it does not encounter the duplicate ID error, which is why this isn't generally visible in libvirt. Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Markus Armbruster <armbru@redhat.com> Cc: Eric Blake <eblake@redhat.com> Cc: Daniel Berrange <berrange@redhat.com> Cc: qemu-stable@nongnu.org Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1496531612-22166-3-git-send-email-mdroth@linux.vnet.ibm.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-06-04 02:13:32 +03:00
object_unparent(obj);
return true;
}
void user_creatable_cleanup(void)
{
object_unparent(object_get_objects_root());
}
static void register_types(void)
{
static const TypeInfo uc_interface_info = {
.name = TYPE_USER_CREATABLE,
.parent = TYPE_INTERFACE,
.class_size = sizeof(UserCreatableClass),
};
type_register_static(&uc_interface_info);
}
type_init(register_types)