sbus: Add struct sbus_request to represent a DBus invocation

struct sbus_request represents a request from a dbus client
being handled by a dbus server implementation. The struct
contains the message, connection and method (and in the
future teh property) which is being requested.

In the future it will contain caller information as well.

sbus_request is a talloc memory context, and is a good place to
attach any allocations and memory specific to the request.

Each handler accepts an sbus_request. If a handler returns
EOK, it is assumed that the handler will finish the request.
Any of the sbus_request_*finish() methods can be used to
complete the request and send back a reply.

sbus_request_return_and_finish() uses the same argument
varargs syntax as dbus_message_append_args(), which isn't
a great syntax. Document it a bit, but don't try to redesign:
The marshalling work (will follow this patch set) will remove
the need to use varargs for most DBus implementation code.

This patch migrates the monitor and data provider dbus code
to use sbus_request, but does not try to rework the talloc
context's to use it.

Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
Reviewed-by: Pavel Březina <pbrezina@redhat.com>
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

2 files changed, 4 insertions, 6 deletions

diff --git a/src/responder/common/responder.h b/src/responder/common/responder.h
index 81082c675..3cf801516 100644
--- a/src/responder/common/responder.h
+++ b/src/responder/common/responder.h
@@ -207,8 +207,7 @@ struct dp_callback_ctx {
 
 void handle_requests_after_reconnect(struct resp_ctx *rctx);
 
-int responder_logrotate(DBusMessage *message,
-                        struct sbus_connection *conn);
+int responder_logrotate(struct sbus_request *dbus_req);
 
 /* Each responder-specific request must create a constructor
  * function that creates a DBus Message that would be sent to
diff --git a/src/responder/common/responder_common.c b/src/responder/common/responder_common.c
index 298994a96..209bf5b01 100644
--- a/src/responder/common/responder_common.c
+++ b/src/responder/common/responder_common.c
@@ -990,17 +990,16 @@ done:
     return ret;
 }
 
-int responder_logrotate(DBusMessage *message,
-                        struct sbus_connection *conn)
+int responder_logrotate(struct sbus_request *dbus_req)
 {
     errno_t ret;
-    struct resp_ctx *rctx = talloc_get_type(sbus_conn_get_private_data(conn),
+    struct resp_ctx *rctx = talloc_get_type(sbus_conn_get_private_data(dbus_req->conn),
                                             struct resp_ctx);
 
     ret = monitor_common_rotate_logs(rctx->cdb, rctx->confdb_service_path);
     if (ret != EOK) return ret;
 
-    return monitor_common_pong(message, conn);
+    return sbus_request_return_and_finish(dbus_req, DBUS_TYPE_INVALID);
 }
 
 void responder_set_fd_limit(rlim_t fd_limit)