core: Add AppArmor profile switching

This permit to switch to a specific apparmor profile when starting a daemon. This
will result in a non operation if apparmor is disabled.
It also add a new build requirement on libapparmor for using this feature.

src/core/dbus-execute.c

@@ -482,6 +482,24 @@ static int property_get_selinux_context(
         return sd_bus_message_append(reply, "(bs)", c->selinux_context_ignore, c->selinux_context);
 }
 
+static int property_get_apparmor_profile(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        ExecContext *c = userdata;
+
+        assert(bus);
+        assert(reply);
+        assert(c);
+
+        return sd_bus_message_append(reply, "(bs)", c->apparmor_profile_ignore, c->apparmor_profile);
+}
+
 static int property_get_personality(
                 sd_bus *bus,
                 const char *path,
@@ -560,6 +578,7 @@ const sd_bus_vtable bus_exec_vtable[] = {
         SD_BUS_PROPERTY("SameProcessGroup", "b", bus_property_get_bool, offsetof(ExecContext, same_pgrp), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("UtmpIdentifier", "s", NULL, offsetof(ExecContext, utmp_id), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("SELinuxContext", "(bs)", property_get_selinux_context, 0, SD_BUS_VTABLE_PROPERTY_CONST),
+        SD_BUS_PROPERTY("AppArmorProfile", "(bs)", property_get_apparmor_profile, 0, SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("IgnoreSIGPIPE", "b", bus_property_get_bool, offsetof(ExecContext, ignore_sigpipe), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("NoNewPrivileges", "b", bus_property_get_bool, offsetof(ExecContext, no_new_privileges), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("SystemCallFilter", "(bas)", property_get_syscall_filter, 0, SD_BUS_VTABLE_PROPERTY_CONST),