HS20 multiple {,required}_roaming_consortium

[Damien Dejean]

Hi there,

I'm currently planning to add the support for multiple home OIs
(required or not) to interworking credentials in wpa_supplicant to
follow Passpoint specifications (v3.2 - §9.1.2 - Description of node
"HomeOIList"). As I'd like to upstream the patches I'm wondering
what's the approach that better fits the project "rules".

As far as I understand, wpa_supplicant supports only one home OI
passed through roaming_consortium or required_roaming_consortium
parameters to interworking credentials and selection phase. To pass
multiple OIs would need these two parameters and struct fields to
become lists/arrays of OIs.

There's two possible solutions:

1.  Keep roaming_consortium and required_roaming_consortium options as
is, but consider them as a list of OIs in the config (like
roaming_consortiums) and convert the matching struct wpa_cred fields
to arrays. It would keep the old configuration files compatible with
the new implementation but it would introduce a kind of inconsistency
between the options/fields name and their content.

2. Rename the two config options and fields to home_ois and
required_home_ois and deprecate
roaming_consortium/required_roaming_consortium fields. The code and
the configuration would be more consistent, but it would break old
configuration files. We may keep the legacy parameters to stay
compatible, and let them set only one OI. In this case they would be
exclusive with the two new options.

Do you have any suggestion/preference on this?

Thanks,
Damien Dejean.