From 3444ebe9cb394662241f22efaf7f3eaf9c8c3587 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Tue, 29 Mar 2011 01:41:42 +0200 Subject: [PATCH] document protocol handler state changes --- DESIGN | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/DESIGN b/DESIGN index 56ea474..02ffe5c 100644 --- a/DESIGN +++ b/DESIGN @@ -104,4 +104,33 @@ to be set up as slave to another protocol handler if necessary (useful for PPPoE or PPTP). -## TODO: Protocol handlers, Configuration management, ubus callbacks + +Protocol handlers +----------------- + +A protocol handler can be attached to anything that provides a callback +for state changes. For the simple case it is usually attached to an interface +directly. + +The state of a protocol handler is tracked in a struct interface_proto_state, +and it depends on the state of the entity that's controlling it. + +It responds to PROTO_CMD_SETUP and PROTO_SETUP_TEARDOWN commands, which +should not block at any point in time. Completion is signalled back to the +master by sending IFPEV_UP and IFPEV_DOWN events. + +If the setup can be done fast without blocking for a noticeable amount of +time, the callback can do it and send back those events immediately. +If the setup can take longer, it should use uloop to schedule its actions +asynchronously and (if necessary) fork. + +The protocol handler must be able to abort a setup request that's being +processed when it encounters a teardown command. + +When a PROTO_SETUP_TEARDOWN call is issued and the 'force' parameter is +set, the protocol handler needs to clean up immediately as good as possible, +without waiting for its pending actions to complete. If it has spawned +any child processes, it needs to kill them and clean up their mess. + + +## TODO: Configuration management, ubus callbacks -- 2.11.0