This adds a new (less severe) blacklist reason as well as an option
to configure the timeout. This blacklist reason will be used in cases
where a BSS has requested IWD roam elsewhere. At that time a new
blacklist entry will be added which will be used along with some
other criteria to determine if IWD should connect/roam to that BSS
again.
Now that we have multiple blacklist reasons there may be situations
where a blacklist entry already exists but with a different reason.
This is going to be handled by the reason severity. Since we have
just two reasons we will treat a connection failure as most severe
and a roam requested as less severe. This leaves us with two
possible situations:
1. BSS is roam blacklisted, then gets connection blacklisted:
The reason will be "promoted" to connection blacklisted.
2. BSS is connection blacklisted, then gets roam blacklisted:
The blacklist request will be ignored
To both prepare for some new blacklisting behavior and allow for
easier consolidation of the network-specific blacklist include a
reason enum for each entry. This allows IWD to differentiate
between multiple blacklist types. For now only the existing
"permanent" type is being added which prevents connections to that
BSS via autoconnect until it expires.
This will allow for blacklisting a BSS if the connection fails. The
actual blacklist module is simple and must be driven by station. All
it does is add BSS addresses, a timestamp, and a timeout to a queue.
Entries can also be removed, or checked if they exist. The blacklist
timeout is configuratble in main.conf, as well as the blacklist
timeout multiplier and maximum timeout. The multiplier is used after
a blacklisted BSS timeout expires but we still fail to connect on the
next connection attempt. We multiply the current timeout by the
multiplier so the BSS remains in the blacklist for a larger growing
amount of time until it reaches the maximum (24 hours by default).
