A new hostapd_cli command, wps_ap_pin, can now be used to manage
AP PIN at runtime. This can be used to generate a random AP PIN and
to only enable the AP PIN for short period (e.g., based on user
action on the AP device). Use of random AP PIN that is only enabled
for short duration is highly recommended to avoid security issues
with a static AP PIN.
As a compromise between usability and security, do not disable
AP PIN permanently based on failed PIN validations. Instead, go to
AP Setup Locked state for increasing amount of time between each
failure to slow down brute force attacks against the AP PIN.
This avoids problems with some external Registrars that may try
to use the same PIN multiple times without user input. Now, the
user will still be able to fix the PIN and try again later while
a real attack is delayed enough to make it impractical.
In theory, this should not really be needed, but Windows 7 uses
Registrar mode to probe AP's WPS capabilities before trying to use
Enrollee and fails if the AP does not allow that probing to happen.
This allows the AP to start as an Enrollee and send M1, but refuse
to continue beyond that (M3 will not be sent if AP PIN is not known).
Call ieee802_11_set_beacon() in addition to set_ap_wps_ie() when
processing WPS IE updates. This is needed with drivers that use
set_beacon() instead of set_ap_wps_ie() (i.e., nl80211).
Doxygen and some build tools may get a bit confused about same file
name being used in different directories. Clean this up a bit by
renaming some of the duplicated file names in src/ap.
