+ m->header = header;
+ m->header_accessible = header_accessible;
+ m->footer = footer;
+ m->footer_accessible = footer_accessible;
+
+ if (BUS_MESSAGE_IS_GVARIANT(m)) {
+ size_t ws;
+
+ if (h->dbus2.cookie == 0)
+ return -EBADMSG;
+
+ /* dbus2 derives the sizes from the message size and
+ the offset table at the end, since it is formatted as
+ gvariant "yyyyuta{tv}v". Since the message itself is a
+ structure with precisely to variable sized entries,
+ there's only one offset in the table, which marks the
+ end of the fields array. */
+
+ ws = bus_gvariant_determine_word_size(message_size, 0);
+ if (footer_accessible < ws)
+ return -EBADMSG;
+
+ m->fields_size = bus_gvariant_read_word_le((uint8_t*) footer + footer_accessible - ws, ws);
+ if (ALIGN8(m->fields_size) > message_size - ws)
+ return -EBADMSG;
+ if (m->fields_size < sizeof(struct bus_header))
+ return -EBADMSG;
+
+ m->fields_size -= sizeof(struct bus_header);
+ m->body_size = message_size - (sizeof(struct bus_header) + ALIGN8(m->fields_size));
+ } else {
+ if (h->dbus1.serial == 0)
+ return -EBADMSG;
+
+ /* dbus1 has the sizes in the header */
+ m->fields_size = BUS_MESSAGE_BSWAP32(m, h->dbus1.fields_size);
+ m->body_size = BUS_MESSAGE_BSWAP32(m, h->dbus1.body_size);
+
+ if (sizeof(struct bus_header) + ALIGN8(m->fields_size) + m->body_size != message_size)
+ return -EBADMSG;
+ }
+