[mirror_qemu.git] / backends / dbus-vmstate.c

/*
 * QEMU dbus-vmstate
 *
 * Copyright (C) 2019 Red Hat Inc
 *
 * Authors:
 *  Marc-André Lureau <marcandre.lureau@redhat.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/osdep.h"
#include "qemu/units.h"
#include "qemu/dbus.h"
#include "qemu/error-report.h"
#include "qapi/error.h"
#include "qom/object_interfaces.h"
#include "qapi/qmp/qerror.h"
#include "migration/vmstate.h"
#include "trace.h"
#include "qom/object.h"


#define TYPE_DBUS_VMSTATE "dbus-vmstate"
OBJECT_DECLARE_SIMPLE_TYPE(DBusVMState, dbus_vmstate,
                           DBUS_VMSTATE, ObjectClass)


struct DBusVMState {
    Object parent;

    GDBusConnection *bus;
    char *dbus_addr;
    char *id_list;

    uint32_t data_size;
    uint8_t *data;
};

static const GDBusPropertyInfo vmstate_property_info[] = {
    { -1, (char *) "Id", (char *) "s",
      G_DBUS_PROPERTY_INFO_FLAGS_READABLE, NULL },
};

static const GDBusPropertyInfo * const vmstate_property_info_pointers[] = {
    &vmstate_property_info[0],
    NULL
};

static const GDBusInterfaceInfo vmstate1_interface_info = {
    -1,
    (char *) "org.qemu.VMState1",
    (GDBusMethodInfo **) NULL,
    (GDBusSignalInfo **) NULL,
    (GDBusPropertyInfo **) &vmstate_property_info_pointers,
    NULL,
};

#define DBUS_VMSTATE_SIZE_LIMIT (1 * MiB)

static GHashTable *
get_id_list_set(DBusVMState *self)
{
    g_auto(GStrv) ids = NULL;
    g_autoptr(GHashTable) set = NULL;
    int i;

    if (!self->id_list) {
        return NULL;
    }

    ids = g_strsplit(self->id_list, ",", -1);
    set = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);
    for (i = 0; ids[i]; i++) {
        g_hash_table_add(set, ids[i]);
        ids[i] = NULL;
    }

    return g_steal_pointer(&set);
}

static GHashTable *
dbus_get_proxies(DBusVMState *self, GError **err)
{
    g_autoptr(GHashTable) proxies = NULL;
    g_autoptr(GHashTable) ids = NULL;
    g_auto(GStrv) names = NULL;
    Error *error = NULL;
    size_t i;

    ids = get_id_list_set(self);
    proxies = g_hash_table_new_full(g_str_hash, g_str_equal,
                                    g_free, g_object_unref);

    names = qemu_dbus_get_queued_owners(self->bus, "org.qemu.VMState1", &error);
    if (!names) {
        g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED, "%s",
                    error_get_pretty(error));
        error_free(error);
        return NULL;
    }

    for (i = 0; names[i]; i++) {
        g_autoptr(GDBusProxy) proxy = NULL;
        g_autoptr(GVariant) result = NULL;
        g_autofree char *id = NULL;
        size_t size;

        proxy = g_dbus_proxy_new_sync(self->bus, G_DBUS_PROXY_FLAGS_NONE,
                    (GDBusInterfaceInfo *) &vmstate1_interface_info,
                    names[i],
                    "/org/qemu/VMState1",
                    "org.qemu.VMState1",
                    NULL, err);
        if (!proxy) {
            return NULL;
        }

        result = g_dbus_proxy_get_cached_property(proxy, "Id");
        if (!result) {
            g_set_error_literal(err, G_IO_ERROR, G_IO_ERROR_FAILED,
                                "VMState Id property is missing.");
            return NULL;
        }

        id = g_variant_dup_string(result, &size);
        if (ids && !g_hash_table_remove(ids, id)) {
            g_clear_pointer(&id, g_free);
            g_clear_object(&proxy);
            continue;
        }
        if (size == 0 || size >= 256) {
            g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED,
                        "VMState Id '%s' is invalid.", id);
            return NULL;
        }

        if (!g_hash_table_insert(proxies, id, proxy)) {
            g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED,
                        "Duplicated VMState Id '%s'", id);
            return NULL;
        }
        id = NULL;
        proxy = NULL;

        g_clear_pointer(&result, g_variant_unref);
    }

    if (ids) {
        g_autofree char **left = NULL;

        left = (char **)g_hash_table_get_keys_as_array(ids, NULL);
        if (*left) {
            g_autofree char *leftids = g_strjoinv(",", left);
            g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED,
                        "Required VMState Id are missing: %s", leftids);
            return NULL;
        }
    }

    return g_steal_pointer(&proxies);
}

static int
dbus_load_state_proxy(GDBusProxy *proxy, const uint8_t *data, size_t size)
{
    g_autoptr(GError) err = NULL;
    g_autoptr(GVariant) result = NULL;
    g_autoptr(GVariant) value = NULL;

    value = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
                                      data, size, sizeof(char));
    result = g_dbus_proxy_call_sync(proxy, "Load",
                                    g_variant_new("(@ay)",
                                                  g_steal_pointer(&value)),
                                    G_DBUS_CALL_FLAGS_NO_AUTO_START,
                                    -1, NULL, &err);
    if (!result) {
        error_report("%s: Failed to Load: %s", __func__, err->message);
        return -1;
    }

    return 0;
}

static int dbus_vmstate_post_load(void *opaque, int version_id)
{
    DBusVMState *self = DBUS_VMSTATE(opaque);
    g_autoptr(GInputStream) m = NULL;
    g_autoptr(GDataInputStream) s = NULL;
    g_autoptr(GError) err = NULL;
    g_autoptr(GHashTable) proxies = NULL;
    uint32_t nelem;

    trace_dbus_vmstate_post_load(version_id);

    proxies = dbus_get_proxies(self, &err);
    if (!proxies) {
        error_report("%s: Failed to get proxies: %s", __func__, err->message);
        return -1;
    }

    m = g_memory_input_stream_new_from_data(self->data, self->data_size, NULL);
    s = g_data_input_stream_new(m);
    g_data_input_stream_set_byte_order(s, G_DATA_STREAM_BYTE_ORDER_BIG_ENDIAN);

    nelem = g_data_input_stream_read_uint32(s, NULL, &err);
    if (err) {
        goto error;
    }

    while (nelem > 0) {
        GDBusProxy *proxy = NULL;
        uint32_t len;
        gsize bytes_read, avail;
        char id[256];

        len = g_data_input_stream_read_uint32(s, NULL, &err);
        if (err) {
            goto error;
        }
        if (len >= 256) {
            error_report("%s: Invalid DBus vmstate proxy name %u",
                         __func__, len);
            return -1;
        }
        if (!g_input_stream_read_all(G_INPUT_STREAM(s), id, len,
                                     &bytes_read, NULL, &err)) {
            goto error;
        }
        g_return_val_if_fail(bytes_read == len, -1);
        id[len] = 0;

        trace_dbus_vmstate_loading(id);

        proxy = g_hash_table_lookup(proxies, id);
        if (!proxy) {
            error_report("%s: Failed to find proxy Id '%s'", __func__, id);
            return -1;
        }

        len = g_data_input_stream_read_uint32(s, NULL, &err);
        avail = g_buffered_input_stream_get_available(
            G_BUFFERED_INPUT_STREAM(s));

        if (len > DBUS_VMSTATE_SIZE_LIMIT || len > avail) {
            error_report("%s: Invalid vmstate size: %u", __func__, len);
            return -1;
        }

        if (dbus_load_state_proxy(proxy,
                g_buffered_input_stream_peek_buffer(G_BUFFERED_INPUT_STREAM(s),
                                                    NULL),
                len) < 0) {
            error_report("%s: Failed to restore Id '%s'", __func__, id);
            return -1;
        }

        if (!g_seekable_seek(G_SEEKABLE(s), len, G_SEEK_CUR, NULL, &err)) {
            goto error;
        }

        nelem -= 1;
    }

    return 0;

error:
    error_report("%s: Failed to read from stream: %s", __func__, err->message);
    return -1;
}

static void
dbus_save_state_proxy(gpointer key,
                      gpointer value,
                      gpointer user_data)
{
    GDataOutputStream *s = user_data;
    const char *id = key;
    GDBusProxy *proxy = value;
    g_autoptr(GVariant) result = NULL;
    g_autoptr(GVariant) child = NULL;
    g_autoptr(GError) err = NULL;
    const uint8_t *data;
    gsize size;

    trace_dbus_vmstate_saving(id);

    result = g_dbus_proxy_call_sync(proxy, "Save",
                                    NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START,
                                    -1, NULL, &err);
    if (!result) {
        error_report("%s: Failed to Save: %s", __func__, err->message);
        return;
    }

    child = g_variant_get_child_value(result, 0);
    data = g_variant_get_fixed_array(child, &size, sizeof(char));
    if (!data) {
        error_report("%s: Failed to Save: not a byte array", __func__);
        return;
    }
    if (size > DBUS_VMSTATE_SIZE_LIMIT) {
        error_report("%s: Too large vmstate data to save: %zu",
                     __func__, (size_t)size);
        return;
    }

    if (!g_data_output_stream_put_uint32(s, strlen(id), NULL, &err) ||
        !g_data_output_stream_put_string(s, id, NULL, &err) ||
        !g_data_output_stream_put_uint32(s, size, NULL, &err) ||
        !g_output_stream_write_all(G_OUTPUT_STREAM(s),
                                   data, size, NULL, NULL, &err)) {
        error_report("%s: Failed to write to stream: %s",
                     __func__, err->message);
    }
}

static int dbus_vmstate_pre_save(void *opaque)
{
    DBusVMState *self = DBUS_VMSTATE(opaque);
    g_autoptr(GOutputStream) m = NULL;
    g_autoptr(GDataOutputStream) s = NULL;
    g_autoptr(GHashTable) proxies = NULL;
    g_autoptr(GError) err = NULL;

    trace_dbus_vmstate_pre_save();

    proxies = dbus_get_proxies(self, &err);
    if (!proxies) {
        error_report("%s: Failed to get proxies: %s", __func__, err->message);
        return -1;
    }

    m = g_memory_output_stream_new_resizable();
    s = g_data_output_stream_new(m);
    g_data_output_stream_set_byte_order(s, G_DATA_STREAM_BYTE_ORDER_BIG_ENDIAN);

    if (!g_data_output_stream_put_uint32(s, g_hash_table_size(proxies),
                                         NULL, &err)) {
        error_report("%s: Failed to write to stream: %s",
                     __func__, err->message);
        return -1;
    }

    g_hash_table_foreach(proxies, dbus_save_state_proxy, s);

    if (g_memory_output_stream_get_size(G_MEMORY_OUTPUT_STREAM(m))
        > UINT32_MAX) {
        error_report("%s: DBus vmstate buffer is too large", __func__);
        return -1;
    }

    if (!g_output_stream_close(G_OUTPUT_STREAM(m), NULL, &err)) {
        error_report("%s: Failed to close stream: %s", __func__, err->message);
        return -1;
    }

    g_free(self->data);
    self->data_size =
        g_memory_output_stream_get_size(G_MEMORY_OUTPUT_STREAM(m));
    self->data =
        g_memory_output_stream_steal_data(G_MEMORY_OUTPUT_STREAM(m));

    return 0;
}

static const VMStateDescription dbus_vmstate = {
    .name = TYPE_DBUS_VMSTATE,
    .version_id = 0,
    .pre_save = dbus_vmstate_pre_save,
    .post_load = dbus_vmstate_post_load,
    .fields = (VMStateField[]) {
        VMSTATE_UINT32(data_size, DBusVMState),
        VMSTATE_VBUFFER_ALLOC_UINT32(data, DBusVMState, 0, 0, data_size),
        VMSTATE_END_OF_LIST()
    }
};

static void
dbus_vmstate_complete(UserCreatable *uc, Error **errp)
{
    DBusVMState *self = DBUS_VMSTATE(uc);
    g_autoptr(GError) err = NULL;

    if (!object_resolve_path_type("", TYPE_DBUS_VMSTATE, NULL)) {
        error_setg(errp, "There is already an instance of %s",
                   TYPE_DBUS_VMSTATE);
        return;
    }

    if (!self->dbus_addr) {
        error_setg(errp, QERR_MISSING_PARAMETER, "addr");
        return;
    }

    self->bus = g_dbus_connection_new_for_address_sync(self->dbus_addr,
                    G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT |
                    G_DBUS_CONNECTION_FLAGS_MESSAGE_BUS_CONNECTION,
                    NULL, NULL, &err);
    if (err) {
        error_setg(errp, "failed to connect to DBus: '%s'", err->message);
        return;
    }

    if (vmstate_register(VMSTATE_IF(self), VMSTATE_INSTANCE_ID_ANY,
                         &dbus_vmstate, self) < 0) {
        error_setg(errp, "Failed to register vmstate");
    }
}

static void
dbus_vmstate_finalize(Object *o)
{
    DBusVMState *self = DBUS_VMSTATE(o);

    vmstate_unregister(VMSTATE_IF(self), &dbus_vmstate, self);

    g_clear_object(&self->bus);
    g_free(self->dbus_addr);
    g_free(self->id_list);
    g_free(self->data);
}

static char *
get_dbus_addr(Object *o, Error **errp)
{
    DBusVMState *self = DBUS_VMSTATE(o);

    return g_strdup(self->dbus_addr);
}

static void
set_dbus_addr(Object *o, const char *str, Error **errp)
{
    DBusVMState *self = DBUS_VMSTATE(o);

    g_free(self->dbus_addr);
    self->dbus_addr = g_strdup(str);
}

static char *
get_id_list(Object *o, Error **errp)
{
    DBusVMState *self = DBUS_VMSTATE(o);

    return g_strdup(self->id_list);
}

static void
set_id_list(Object *o, const char *str, Error **errp)
{
    DBusVMState *self = DBUS_VMSTATE(o);

    g_free(self->id_list);
    self->id_list = g_strdup(str);
}

static char *
dbus_vmstate_get_id(VMStateIf *vmif)
{
    return g_strdup(TYPE_DBUS_VMSTATE);
}

static void
dbus_vmstate_class_init(ObjectClass *oc, void *data)
{
    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
    VMStateIfClass *vc = VMSTATE_IF_CLASS(oc);

    ucc->complete = dbus_vmstate_complete;
    vc->get_id = dbus_vmstate_get_id;

    object_class_property_add_str(oc, "addr",
                                  get_dbus_addr, set_dbus_addr);
    object_class_property_add_str(oc, "id-list",
                                  get_id_list, set_id_list);
}

static const TypeInfo dbus_vmstate_info = {
    .name = TYPE_DBUS_VMSTATE,
    .parent = TYPE_OBJECT,
    .instance_size = sizeof(DBusVMState),
    .instance_finalize = dbus_vmstate_finalize,
    .class_size = sizeof(DBusVMStateClass),
    .class_init = dbus_vmstate_class_init,
    .interfaces = (InterfaceInfo[]) {
        { TYPE_USER_CREATABLE },
        { TYPE_VMSTATE_IF },
        { }
    }
};

static void
register_types(void)
{
    type_register_static(&dbus_vmstate_info);
}

type_init(register_types);
Commit	Line	Data
5010cec2 MAL	1	/*
	2	* QEMU dbus-vmstate
	3	*
	4	* Copyright (C) 2019 Red Hat Inc
	5	*
	6	* Authors:
	7	* Marc-André Lureau <marcandre.lureau@redhat.com>
	8	*
	9	* This work is licensed under the terms of the GNU GPL, version 2 or later.
	10	* See the COPYING file in the top-level directory.
	11	*/
	12
	13	#include "qemu/osdep.h"
	14	#include "qemu/units.h"
	15	#include "qemu/dbus.h"
	16	#include "qemu/error-report.h"
	17	#include "qapi/error.h"
	18	#include "qom/object_interfaces.h"
	19	#include "qapi/qmp/qerror.h"
	20	#include "migration/vmstate.h"
	21	#include "trace.h"
db1015e9	22	#include "qom/object.h"
5010cec2	23
5010cec2 MAL	24
5010cec2 MAL	25	#define TYPE_DBUS_VMSTATE "dbus-vmstate"
1ff5adfa EH	26	OBJECT_DECLARE_SIMPLE_TYPE(DBusVMState, dbus_vmstate,
1ff5adfa EH	27	DBUS_VMSTATE, ObjectClass)
5010cec2	28
5010cec2 MAL	29
	30	struct DBusVMState {
	31	Object parent;
	32
	33	GDBusConnection *bus;
	34	char *dbus_addr;
	35	char *id_list;
	36
	37	uint32_t data_size;
	38	uint8_t *data;
	39	};
	40
	41	static const GDBusPropertyInfo vmstate_property_info[] = {
	42	{ -1, (char ) "Id", (char ) "s",
	43	G_DBUS_PROPERTY_INFO_FLAGS_READABLE, NULL },
	44	};
	45
	46	static const GDBusPropertyInfo * const vmstate_property_info_pointers[] = {
	47	&vmstate_property_info[0],
	48	NULL
	49	};
	50
	51	static const GDBusInterfaceInfo vmstate1_interface_info = {
	52	-1,
	53	(char *) "org.qemu.VMState1",
	54	(GDBusMethodInfo **) NULL,
	55	(GDBusSignalInfo **) NULL,
	56	(GDBusPropertyInfo **) &vmstate_property_info_pointers,
	57	NULL,
	58	};
	59
	60	#define DBUS_VMSTATE_SIZE_LIMIT (1 * MiB)
	61
	62	static GHashTable *
	63	get_id_list_set(DBusVMState *self)
	64	{
	65	g_auto(GStrv) ids = NULL;
	66	g_autoptr(GHashTable) set = NULL;
	67	int i;
	68
	69	if (!self->id_list) {
	70	return NULL;
	71	}
	72
	73	ids = g_strsplit(self->id_list, ",", -1);
	74	set = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);
	75	for (i = 0; ids[i]; i++) {
	76	g_hash_table_add(set, ids[i]);
	77	ids[i] = NULL;
	78	}
	79
	80	return g_steal_pointer(&set);
	81	}
	82
	83	static GHashTable *
	84	dbus_get_proxies(DBusVMState self, GError *err)
	85	{
	86	g_autoptr(GHashTable) proxies = NULL;
	87	g_autoptr(GHashTable) ids = NULL;
	88	g_auto(GStrv) names = NULL;
	89	Error *error = NULL;
	90	size_t i;
	91
	92	ids = get_id_list_set(self);
93	proxies = g_hash_table_new_full(g_str_hash, g_str_equal,
94	g_free, g_object_unref);
95
96	names = qemu_dbus_get_queued_owners(self->bus, "org.qemu.VMState1", &error);
97	if (!names) {
98	g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED, "%s",
99	error_get_pretty(error));
100	error_free(error);
101	return NULL;
102	}
103
104	for (i = 0; names[i]; i++) {
105	g_autoptr(GDBusProxy) proxy = NULL;
106	g_autoptr(GVariant) result = NULL;
107	g_autofree char *id = NULL;
108	size_t size;
109
110	proxy = g_dbus_proxy_new_sync(self->bus, G_DBUS_PROXY_FLAGS_NONE,
111	(GDBusInterfaceInfo *) &vmstate1_interface_info,
112	names[i],
113	"/org/qemu/VMState1",
114	"org.qemu.VMState1",
115	NULL, err);
116	if (!proxy) {
117	return NULL;
118	}
119
120	result = g_dbus_proxy_get_cached_property(proxy, "Id");
121	if (!result) {
122	g_set_error_literal(err, G_IO_ERROR, G_IO_ERROR_FAILED,
123	"VMState Id property is missing.");
124	return NULL;
125	}
126
127	id = g_variant_dup_string(result, &size);
128	if (ids && !g_hash_table_remove(ids, id)) {
129	g_clear_pointer(&id, g_free);
130	g_clear_object(&proxy);
131	continue;
132	}
133	if (size == 0 \|\| size >= 256) {
134	g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED,
135	"VMState Id '%s' is invalid.", id);
136	return NULL;
137	}
138
139	if (!g_hash_table_insert(proxies, id, proxy)) {
140	g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED,
141	"Duplicated VMState Id '%s'", id);
142	return NULL;
143	}
144	id = NULL;
145	proxy = NULL;
146
147	g_clear_pointer(&result, g_variant_unref);
148	}
149
150	if (ids) {
151	g_autofree char **left = NULL;
152
153	left = (char **)g_hash_table_get_keys_as_array(ids, NULL);
154	if (*left) {
155	g_autofree char *leftids = g_strjoinv(",", left);
156	g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED,
157	"Required VMState Id are missing: %s", leftids);
158	return NULL;
159	}
160	}
161
162	return g_steal_pointer(&proxies);
163	}
164
165	static int
166	dbus_load_state_proxy(GDBusProxy proxy, const uint8_t data, size_t size)
167	{
168	g_autoptr(GError) err = NULL;
169	g_autoptr(GVariant) result = NULL;
170	g_autoptr(GVariant) value = NULL;
171
172	value = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
173	data, size, sizeof(char));
174	result = g_dbus_proxy_call_sync(proxy, "Load",
175	g_variant_new("(@ay)",
176	g_steal_pointer(&value)),
177	G_DBUS_CALL_FLAGS_NO_AUTO_START,
178	-1, NULL, &err);
179	if (!result) {
180	error_report("%s: Failed to Load: %s", __func__, err->message);
181	return -1;
182	}
183
184	return 0;
185	}
186
187	static int dbus_vmstate_post_load(void *opaque, int version_id)
188	{
189	DBusVMState *self = DBUS_VMSTATE(opaque);
190	g_autoptr(GInputStream) m = NULL;
191	g_autoptr(GDataInputStream) s = NULL;
192	g_autoptr(GError) err = NULL;
193	g_autoptr(GHashTable) proxies = NULL;
194	uint32_t nelem;
195
196	trace_dbus_vmstate_post_load(version_id);
197
198	proxies = dbus_get_proxies(self, &err);
199	if (!proxies) {
200	error_report("%s: Failed to get proxies: %s", __func__, err->message);
201	return -1;
202	}
203
204	m = g_memory_input_stream_new_from_data(self->data, self->data_size, NULL);
205	s = g_data_input_stream_new(m);
206	g_data_input_stream_set_byte_order(s, G_DATA_STREAM_BYTE_ORDER_BIG_ENDIAN);
207
208	nelem = g_data_input_stream_read_uint32(s, NULL, &err);
209	if (err) {
210	goto error;
211	}
212
213	while (nelem > 0) {
214	GDBusProxy *proxy = NULL;
215	uint32_t len;
216	gsize bytes_read, avail;
217	char id[256];
218
219	len = g_data_input_stream_read_uint32(s, NULL, &err);
220	if (err) {
221	goto error;
222	}
223	if (len >= 256) {
224	error_report("%s: Invalid DBus vmstate proxy name %u",
225	__func__, len);
226	return -1;
227	}
228	if (!g_input_stream_read_all(G_INPUT_STREAM(s), id, len,
229	&bytes_read, NULL, &err)) {
230	goto error;
231	}
232	g_return_val_if_fail(bytes_read == len, -1);
233	id[len] = 0;
234
235	trace_dbus_vmstate_loading(id);
236
237	proxy = g_hash_table_lookup(proxies, id);
238	if (!proxy) {
239	error_report("%s: Failed to find proxy Id '%s'", __func__, id);
240	return -1;
241	}
242
243	len = g_data_input_stream_read_uint32(s, NULL, &err);
244	avail = g_buffered_input_stream_get_available(
245	G_BUFFERED_INPUT_STREAM(s));
246
247	if (len > DBUS_VMSTATE_SIZE_LIMIT \|\| len > avail) {
248	error_report("%s: Invalid vmstate size: %u", __func__, len);
249	return -1;
250	}
251
252	if (dbus_load_state_proxy(proxy,
253	g_buffered_input_stream_peek_buffer(G_BUFFERED_INPUT_STREAM(s),
254	NULL),
255	len) < 0) {
256	error_report("%s: Failed to restore Id '%s'", __func__, id);
257	return -1;
258	}
259
260	if (!g_seekable_seek(G_SEEKABLE(s), len, G_SEEK_CUR, NULL, &err)) {
261	goto error;
262	}
263
264	nelem -= 1;
265	}
266
267	return 0;
268
269	error:
270	error_report("%s: Failed to read from stream: %s", __func__, err->message);
271	return -1;
272	}
273
274	static void
275	dbus_save_state_proxy(gpointer key,
276	gpointer value,
277	gpointer user_data)
278	{
279	GDataOutputStream *s = user_data;
280	const char *id = key;
281	GDBusProxy *proxy = value;
282	g_autoptr(GVariant) result = NULL;
283	g_autoptr(GVariant) child = NULL;
284	g_autoptr(GError) err = NULL;
285	const uint8_t *data;
286	gsize size;
287
288	trace_dbus_vmstate_saving(id);
289
290	result = g_dbus_proxy_call_sync(proxy, "Save",
291	NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START,
292	-1, NULL, &err);
293	if (!result) {
294	error_report("%s: Failed to Save: %s", __func__, err->message);
295	return;
296	}
297
298	child = g_variant_get_child_value(result, 0);
299	data = g_variant_get_fixed_array(child, &size, sizeof(char));
300	if (!data) {
301	error_report("%s: Failed to Save: not a byte array", __func__);
302	return;
303	}
304	if (size > DBUS_VMSTATE_SIZE_LIMIT) {
305	error_report("%s: Too large vmstate data to save: %zu",
306	__func__, (size_t)size);
307	return;
308	}
309
310	if (!g_data_output_stream_put_uint32(s, strlen(id), NULL, &err) \|\|
311	!g_data_output_stream_put_string(s, id, NULL, &err) \|\|
312	!g_data_output_stream_put_uint32(s, size, NULL, &err) \|\|
313	!g_output_stream_write_all(G_OUTPUT_STREAM(s),
314	data, size, NULL, NULL, &err)) {
315	error_report("%s: Failed to write to stream: %s",
316	__func__, err->message);
317	}
318	}
319
320	static int dbus_vmstate_pre_save(void *opaque)
321	{
322	DBusVMState *self = DBUS_VMSTATE(opaque);
323	g_autoptr(GOutputStream) m = NULL;
324	g_autoptr(GDataOutputStream) s = NULL;
325	g_autoptr(GHashTable) proxies = NULL;
326	g_autoptr(GError) err = NULL;
327
328	trace_dbus_vmstate_pre_save();
329
330	proxies = dbus_get_proxies(self, &err);
331	if (!proxies) {
332	error_report("%s: Failed to get proxies: %s", __func__, err->message);
333	return -1;
334	}
335
336	m = g_memory_output_stream_new_resizable();
337	s = g_data_output_stream_new(m);
338	g_data_output_stream_set_byte_order(s, G_DATA_STREAM_BYTE_ORDER_BIG_ENDIAN);
339
340	if (!g_data_output_stream_put_uint32(s, g_hash_table_size(proxies),
341	NULL, &err)) {
342	error_report("%s: Failed to write to stream: %s",
343	__func__, err->message);
344	return -1;
345	}
346
347	g_hash_table_foreach(proxies, dbus_save_state_proxy, s);
348
349	if (g_memory_output_stream_get_size(G_MEMORY_OUTPUT_STREAM(m))
350	> UINT32_MAX) {
351	error_report("%s: DBus vmstate buffer is too large", __func__);
352	return -1;
353	}
354
355	if (!g_output_stream_close(G_OUTPUT_STREAM(m), NULL, &err)) {
356	error_report("%s: Failed to close stream: %s", __func__, err->message);
357	return -1;
358	}
359
360	g_free(self->data);
361	self->data_size =
362	g_memory_output_stream_get_size(G_MEMORY_OUTPUT_STREAM(m));
363	self->data =
364	g_memory_output_stream_steal_data(G_MEMORY_OUTPUT_STREAM(m));
365
366	return 0;
367	}
368
369	static const VMStateDescription dbus_vmstate = {
370	.name = TYPE_DBUS_VMSTATE,
371	.version_id = 0,
372	.pre_save = dbus_vmstate_pre_save,
373	.post_load = dbus_vmstate_post_load,
374	.fields = (VMStateField[]) {
375	VMSTATE_UINT32(data_size, DBusVMState),
376	VMSTATE_VBUFFER_ALLOC_UINT32(data, DBusVMState, 0, 0, data_size),
377	VMSTATE_END_OF_LIST()
378	}
379	};
380
381	static void
382	dbus_vmstate_complete(UserCreatable uc, Error *errp)
383	{
384	DBusVMState *self = DBUS_VMSTATE(uc);
385	g_autoptr(GError) err = NULL;
386
387	if (!object_resolve_path_type("", TYPE_DBUS_VMSTATE, NULL)) {
388	error_setg(errp, "There is already an instance of %s",
389	TYPE_DBUS_VMSTATE);
390	return;
391	}
392
393	if (!self->dbus_addr) {
394	error_setg(errp, QERR_MISSING_PARAMETER, "addr");
395	return;
396	}
397
398	self->bus = g_dbus_connection_new_for_address_sync(self->dbus_addr,
399	G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT \|
400	G_DBUS_CONNECTION_FLAGS_MESSAGE_BUS_CONNECTION,
401	NULL, NULL, &err);
402	if (err) {
403	error_setg(errp, "failed to connect to DBus: '%s'", err->message);
404	return;
405	}
406
1df2c9a2 PX	407	if (vmstate_register(VMSTATE_IF(self), VMSTATE_INSTANCE_ID_ANY,
1df2c9a2 PX	408	&dbus_vmstate, self) < 0) {
5010cec2 MAL	409	error_setg(errp, "Failed to register vmstate");
	410	}
	411	}
	412
	413	static void
	414	dbus_vmstate_finalize(Object *o)
	415	{
	416	DBusVMState *self = DBUS_VMSTATE(o);
	417
	418	vmstate_unregister(VMSTATE_IF(self), &dbus_vmstate, self);
	419
	420	g_clear_object(&self->bus);
	421	g_free(self->dbus_addr);
	422	g_free(self->id_list);
	423	g_free(self->data);
	424	}
	425
	426	static char *
	427	get_dbus_addr(Object o, Error *errp)
	428	{
	429	DBusVMState *self = DBUS_VMSTATE(o);
	430
	431	return g_strdup(self->dbus_addr);
	432	}
	433
	434	static void
	435	set_dbus_addr(Object o, const char str, Error **errp)
	436	{
	437	DBusVMState *self = DBUS_VMSTATE(o);
	438
	439	g_free(self->dbus_addr);
	440	self->dbus_addr = g_strdup(str);
	441	}
	442
	443	static char *
	444	get_id_list(Object o, Error *errp)
	445	{
	446	DBusVMState *self = DBUS_VMSTATE(o);
	447
	448	return g_strdup(self->id_list);
	449	}
	450
	451	static void
	452	set_id_list(Object o, const char str, Error **errp)
	453	{
	454	DBusVMState *self = DBUS_VMSTATE(o);
	455
	456	g_free(self->id_list);
	457	self->id_list = g_strdup(str);
	458	}
	459
	460	static char *
	461	dbus_vmstate_get_id(VMStateIf *vmif)
	462	{
	463	return g_strdup(TYPE_DBUS_VMSTATE);
	464	}
	465
	466	static void
	467	dbus_vmstate_class_init(ObjectClass oc, void data)
	468	{
	469	UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
	470	VMStateIfClass *vc = VMSTATE_IF_CLASS(oc);
	471
	472	ucc->complete = dbus_vmstate_complete;
473	vc->get_id = dbus_vmstate_get_id;
474
475	object_class_property_add_str(oc, "addr",
d2623129	476	get_dbus_addr, set_dbus_addr);
5010cec2	477	object_class_property_add_str(oc, "id-list",
d2623129	478	get_id_list, set_id_list);
5010cec2 MAL	479	}
	480
	481	static const TypeInfo dbus_vmstate_info = {
	482	.name = TYPE_DBUS_VMSTATE,
	483	.parent = TYPE_OBJECT,
	484	.instance_size = sizeof(DBusVMState),
	485	.instance_finalize = dbus_vmstate_finalize,
	486	.class_size = sizeof(DBusVMStateClass),
	487	.class_init = dbus_vmstate_class_init,
	488	.interfaces = (InterfaceInfo[]) {
	489	{ TYPE_USER_CREATABLE },
	490	{ TYPE_VMSTATE_IF },
	491	{ }
	492	}
	493	};
	494
	495	static void
	496	register_types(void)
	497	{
	498	type_register_static(&dbus_vmstate_info);
	499	}
	500
	501	type_init(register_types);