tree 750cebc7d0f0e611955ebc5dd005d8fd0384c561
parent d70eef64210d8552c83ba4006edf9ebffc534661
author Philipp Maier <pmaier@sysmocom.de> 1626254416 +0200
committer Philipp Maier <pmaier@sysmocom.de> 1626793209 +0200

mgcp_protocol: refactor MGCP request handling

At the moment the MGCP request handling and message parsing is not
clearly separated. The function mgcp_parse_header() in mgcp_msg.c is
also responsible for resolving an endpoint. This leads to unclear layer
separation. We eventually end up in a situation where we can not execute
any request handler without beeing able to resolve an endpoint, however
this is necessary if we want to implement wildcarded DLCX resquests.

In the current situation a wildcarded DLCX is not possible to implement
as we always have to resolve a an to get to the trunk which we need to
iterate. However, we just can't resolve a free endpoint in a situation
where all endpoints on te trunk are in use.

We have to refactor the request handler so that the parsing in mgcp_msg
only extracts us the endpoint name. The resolving is then done in
mgcp_handle_message() in mgcp_protocol.c. Then we are able to decide
what to do if we are unable to resolve an endpoint but still be able to
resolve the trunk.

This patch does not change the behaviour of osmo-mgw yet, but it lays
the foundation for request handler implementations that can still
perform useful actions if no endpoint but a trunk has been resolved. A
wilcarded DLCX is such a case. It does not need an endpoint, just the
trunk.

Change-Id: I9f519d8a0ee8a513fa1e74acf3ee7dbc0991cdde
Related: SYS#5535