Revert "Revert "sd-bus: change serialization of kdbus messages to qualify in their entirety as gvariant objects""

This reverts commit 954871d8ba15911d014f76ed2c7a9492953cf39d.

1 files changed, 26 insertions, 9 deletions

diff --git a/src/libsystemd/sd-bus/bus-protocol.h b/src/libsystemd/sd-bus/bus-protocol.h
index 6431dfbff8..183af89a63 100644
--- a/src/libsystemd/sd-bus/bus-protocol.h
+++ b/src/libsystemd/sd-bus/bus-protocol.h
@@ -23,21 +23,38 @@
 
 #include <endian.h>
 
+#include "macro.h"
+
 /* Packet header */
 
-struct bus_header {
+struct _packed_ bus_header {
+        /* The first four fields are identical for dbus1, and dbus2 */
         uint8_t endian;
         uint8_t type;
         uint8_t flags;
         uint8_t version;
-        uint32_t body_size;
-
-        /* Note that what the bus spec calls "serial" we'll call
-        "cookie" instead, because we don't want to imply that the
-        cookie was in any way monotonically increasing. */
-        uint32_t serial;
-        uint32_t fields_size;
-} _packed_;
+
+        union _packed_ {
+                /* dbus1: Used for SOCK_STREAM connections */
+                struct _packed_ {
+                        uint32_t body_size;
+
+                        /* Note that what the bus spec calls "serial" we'll call
+                           "cookie" instead, because we don't want to imply that the
+                           cookie was in any way monotonically increasing. */
+                        uint32_t serial;
+                        uint32_t fields_size;
+                } dbus1;
+
+                /* dbus2: Used for kdbus connections */
+                struct _packed_ {
+                        uint32_t _reserved;
+                        uint64_t cookie;
+                } dbus2;
+
+                /* Note that both header versions have the same size! */
+        };
+};
 
 /* Endianness */