iwd/doc/features.txt

IWD
===

- IWD will start a scheduled scan to the interface if the hardware supports
that feature. If the iwd closes or dies so that the kernel netlink socket
is closed, then the scheduled scan is cancelled automatically if the kernel
supports this. This is done by giving NL80211_ATTR_SOCKET_OWNER netlink
attribute when initiating the scheduled scan.

- IWD contains a network object that will contain a list of BSS that have the
same SSID and security setting. From user point of view, we will connect to
a certain SSID instead of connecting directly to a BSS. IWD will then pick
the best BSS automatically from the BSS list when connecting to a SSID.
The "best" BSS in this context is the BSS that has the highest signal strength.

- IWD uses the DBus agent interface to query information from the user.
The information asked include things like passphrase etc. The user can
register only one agent to iwd. If the user does not respond in timely
manner to the query, then the pending user request is cancelled after a
timeout. The pending user request is also cancelled if user disconnects a
pending connection attempt.

- IWD supports the full RSN 4-Way Handshake for PTK generation.  Support for
handling the optional (second) RSN element from the AP is included.

- IWD supports Pre-authentication from 802.11-2007.  If the currently
connected AP supports pre-authentication and iwd determines that a roam is
required, then the pre-authentication process is kicked off.  This is done
using the current connection, running 802.1X over 0x88c7 protocol. This results
in the creation of a new PMK which is cached by both the target and iwd.  iwd
can then roam onto the target AP using the cached PMK.

- IWD supports Fast Transitions for fast roaming between access points.  Only
FT-over-Air (fastest option) is currently supported by iwd.  Whenever iwd
determines that a roam is required and a suitable target that supports fast
transitions is available, iwd roams to the target AP using FT automatically.

- IWD supports Radio Resource Management from 802.11k.  In particular iwd
can request and utilize Neighbor Reports.  When iwd determines that a roam
is required, iwd will try to obtain a Neighbor Report from the currently
connected AP (using a special Action frame).  This enables iwd to optimize
the list of channels to scan in order to find a suitable target for roaming
much quicker.

- IWD supports receiving and generating SA Query action frames. If there is a
spoofed disassociate frame, IWD will generate a SA Query frame to ask the AP if
the disassociate frame was valid. The alternate case is if the AP receives
an (re)associate frame while the STA is still connected. In this case the AP
will send an SA Query frame, which IWD will respond to if it is still connected.

- IWD supports the following EAP methods:
        - EAP-SIM
        - EAP-AKA
        - EAP-AKA'
        - EAP-GTC
        - EAP-MD5
        - EAP-MSCHAPV2
        - EAP-TLS
        - EAP-WSC
        - EAP-PEAP
        - EAP-TTLS

Wireless monitor
================

Netlink monitor interface is created if it does not exist

The iwmon utility automates netlink monitor creation by by using RTNL
to find an existing netlink monitor interface, and in case it does not
exist, create a new one. By default the netlink monitor interface is
named 'nlmon'. Another name can be given with the '--interface'
command line option.

Once iwmon terminates, the netlink monitor interface is removed (in
case iwmon created it).


HWSIM
=====

The radio id from kernel mac80211_hwsim module is parsed properly in
hwsim. The radio id is not returned as HWSIM_ATTR_RADIO_ID but instead
it is returned in error message. If the error code > 0, then that means
the radio id. If the error code < 0, then that indicates a real error.

The hwsim uses new HWSIM_ATTR_DESTROY_RADIO_ON_CLOSE flag attribute to
tell the kernel that when the hwsim process dies, the radios it created
should be removed. For testing tools it is beneficial if the newly
created radio could be bound to the lifetime of the netlink socket.
Alternatively, using the hwsim '-k (--keep)' command line option instructs
hwsim to not destroy the created radio automatically.

The hwsim is using HWSIM_CMD_NEW_RADIO to create a new radio. When the
radio has been created, the kernel will return the used radio id and
parameters in a HWSIM_CMD_NEW_RADIO multicast event that is sent in
"config" netlink multicast group. The command HWSIM_CMD_DEL_RADIO is sent
by kernel when a hwsim radio is deleted. In this case the deleted
radio id is sent to "config" netlink multicast group.

hwsim can list radios by sending a HWSIM_CMD_GET_RADIO with the attribute
HWSIM_ATTR_RADIO_ID containing the desired radio id. If no radio id is
given on the command line, a dump of all radios is requested from the
kernel. The attributes returned are identical to those sent to the
'config' multicast group when creating a radio.