Allow to have per-interface wpa_supplicant.conf (wpa_supplicant.conf.${ifname})

[AMDmi3]

Summary

I don't know much of how wpa_supplicant work, but I've encountered
the following problem: apart from usual WPA wlans I use secure wired
connection at work which requires wpa_supplicant as well. The problem
is that the wired connection requires ap_scan=0 set in the config and
doesn't work otherwise (wireless connections, on the contrary, do
not work with ap_scan=0 and only work with ap_scan=1 which is the
default). Since ap_scan is set config-wide (e.g. cannot be set on
per-network basis), the only solution I've came to is to have separate
configs for wired and wireless connections.

The change to /etc/rc.d/wpa_supplicant is minimal and backwards
compatible, however I suspect that documentation changes are also
needed if this patch is accepted.

Test Plan

Works for me with separate /etc/wpa_supplicant.conf.em0 and
/etc/wpa_supplicant.conf.wlan0 configs with ap_scan=0 set in the
former.

[brooks]

This seems reasonable to me. I'd prefer /etc/wpa_supplicant.d/em0.conf in place of /etc/wpa_supplicant.conf.em0.

[AMDmi3]

In D13587#288458, @brooks wrote:

This seems reasonable to me. I'd prefer /etc/wpa_supplicant.d/em0.conf in place of /etc/wpa_supplicant.conf.em0.

You sure this is a good idea? The de-facto standard for dir.d configuration directories is to just store generic configuration chunks. This makes configuration easier as you can just copy a set of topic-oriented chunks into the directory and get a properly configured service. I'm already very much annoyed with what we do with /etc/rc.conf.d/, which assigns a special meanings and limits scope for configuration files (e.g. /etc/rc.conf.d/foo only affects rc.d/foo script, and you can not just put e.g. /etc/rc.conf.d/my-webserver which configures nginx, apache, syslog and firewall for your web server), making it practically useless.

Same here, I'd expect /etc/wpa_supplicant.conf.d to store generic configuration chunks so I could put e.g. my-home-networks and my-work-networks with the lists of specific network={} entries.

Interface differentiation is whole another layer of configuration, so it seems to be more logical to have /etc/wpa_supplicant.conf.IFNAME and /etc/wpa_supplicant.conf.IFNAME.d for that purpose (we don't seem to support wpa_supplicant.conf.d at all now though, so I'm not touching it).

[cy]

In D13587#288458, @brooks wrote:

This seems reasonable to me. I'd prefer /etc/wpa_supplicant.d/em0.conf in place of /etc/wpa_supplicant.conf.em0.

Agreed.

[cy]

In D13587#289412, @AMDmi3 wrote:

In D13587#288458, @brooks wrote:

This seems reasonable to me. I'd prefer /etc/wpa_supplicant.d/em0.conf in place of /etc/wpa_supplicant.conf.em0.

You sure this is a good idea? The de-facto standard for dir.d configuration directories is to just store generic configuration chunks. This makes configuration easier as you can just copy a set of topic-oriented chunks into the directory and get a properly configured service. I'm already very much annoyed with what we do with /etc/rc.conf.d/, which assigns a special meanings and limits scope for configuration files (e.g. /etc/rc.conf.d/foo only affects rc.d/foo script, and you can not just put e.g. /etc/rc.conf.d/my-webserver which configures nginx, apache, syslog and firewall for your web server), making it practically useless.

How would you propose to do that? AFAIK wpa_supplicant doesn't support including files.

Same here, I'd expect /etc/wpa_supplicant.conf.d to store generic configuration chunks so I could put e.g. my-home-networks and my-work-networks with the lists of specific network={} entries.

Interface differentiation is whole another layer of configuration, so it seems to be more logical to have /etc/wpa_supplicant.conf.IFNAME and /etc/wpa_supplicant.conf.IFNAME.d for that purpose (we don't seem to support wpa_supplicant.conf.d at all now though, so I'm not touching it).

I'm not enamoured with a proliferation of wpa_supplicant.conf.IFNAME files in /etc. It's more onerous to view a listing.

[AMDmi3]

How about wpa_supplicant.if.d/${ifn}.conf then?