iwd/TODO

Background
==========

- Priority scale: High, Medium and Low

- Complexity scale: C1, C2, C4 and C8.  The complexity scale is exponential,
  with complexity 1 being the lowest complexity.  Complexity is a function
  of both task 'complexity' and task 'scope'.

  The general rule of thumb is that a complexity 1 task should take 1-2 weeks
  for a person very familiar with the codebase.  Higher complexity tasks
  require more time and have higher uncertainty.

  Higher complexity tasks should be refined into several lower complexity tasks
  once the task is better understood.


mac80211_hwsim
==============

- Add support for HWSIM_CMD_SET_RADIO command

  To allow modifying an existing radio, add the HWSIM_CMD_SET_RADIO.  The
  first possible feature should be to emulate the hardware RFKILL switch.

  It might be required to add a HWSIM_ATTR_RADIO_HW_RFKILL attribute flag
  to the HWSIM_CMD_NEW_RADIO to enable virtual radios with a hardware
  level RFKILL switch.

  Priority: Medium
  Complexity: C1

- Allow configuration of MAC address or list of MAC addresses

  The radios are auto-generating a fake MAC address.  It would be useful
  to allow specifying a MAC address to be used.  In certain cases it might
  be also useful to provide a list of MAC addresses so that for example
  with secondary interfaces these can be used.

  Priority: Low
  Complexity: C2

- Move mac80211_hwsim.h header file to UAPI includes

  The mac80211_hwsim.h is the public API description of this netlink
  interface and thus it should be provided via UAPI includes.

  For this work work the mac80211_hwsim.h header needs to be modified
  so that it also compiles from userspace.  At the moment it throws
  errors.  And it needs to become part of the UAPI headers of the
  Linux kernel.

  In addition it should provide HWSIM_GENL_NAME that provides the
  generic netlink "MAC82011_HWSIM" family string.

  Priority: Low
  Complexity: C1

- Provide kernel option to allow defining the number of initial radios

  By default the mac80211_hwsim modules creates 2 radios by default unless
  it is overwritten with the radios=x module parameter.

  To allow loading the mac80211_hwsim by default and even with accidental
  loading of the module, it would be good to provide a kernel configuration
  option that allows changing the default value here.

  For our testing we want to load mac80211_hwsim without any radios. Maybe
  this should be the default for the new kernel option.

  If the default of initial radios can be changed to zero, then it is also
  possible to add MODULE_ALIAS_GENL_FAMILY to support auto-loading of
  the mac80211_hwsim kernel module.

  Priority: Low
  Complexity: C1

- New configuration options for radios

  At the moment the radios created are all equal and feature rich.  However
  for testing we want to create radios with different emulated hardware
  capabilities.  Provide new attributes or flags that allow enabling or
  disabling certain mac80211 features.

  For example AP mode, P2P mode, number of interface combinations, TDLS
  support, number of Scan SSIDs, supported ciphers and so on.

  Priority: Low
  Complexity: C2


cfg80211 / nl80211
==================

- Disconnect from network / station when client crashes

  When associating or connecting to a network, it should be possible to
  bind this transaction to a specific netlink client.  So that in case
  this client terminates without, any connection will be also terminated.

  This should affect NL80211_CMD_ASSOCIATE and NL80211_CMD_CONNECT.  It
  seems that this is not needed for NL80211_CMD_AUTHENTICATE since that
  command will eventually time out, but it might be a good idea to even
  support it there.

  Maybe a new attribute similar to NL80211_ATTR_IFACE_SOCKET_OWNER should
  be used for this behavior.

  Priority: High
  Complexity: C4

- Add missing support for NL80211_CMD_GET_INTERFACE filtering

  The NL80211_CMD_GET_INTERFACE command description indicates that you
  can filter results based NL80211_ATTR_WIPHY.  This feature has never
  been implemented.

  Either remove that feature from the description since it does not exist
  or actually implemented the filtering on wiphy.  Johannes indicated that
  fixing the description might be the better approach.  If the feature is
  easy to add, then it should be added.  However if filtering on wiphy is
  a rather complicated task, then better just update the description to
  match the reality.

  Priority: Low
  Complexity: C2


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

- Decode HT Capabilities IE element

  HT Capabilities element has ID 45.

  Priority: Medium
  Complexity: C1

- Decode HT Operation IE element

  HT Operation element has ID 61.

  Priority: Medium
  Complexity: C1
  Owner: Patrik Flykt <patrik.flykt@linux.intel.com>

- Add support for PACKET_RECV_OUTPUT socket option of AF_PACKET

  Instead of having to switch every interface manually into promiscuous
  mode, it would be useful to set PACKET_RECV_OUTPUT to receive also
  the traffic that leaves the system.

  This would make tracing PAE / EAPoL traffic easy and provides better
  sniffing capabilities.

  Unfortunately, PACKET_RECV_OUTPUT logic is not implemented at all in
  the kernel. So, first implement it in the kernel, and then use it in
  nlmon.c as a set_sockopt option.

  Priority: Low
  Complexity: C8

- Subscribe to all nl80211 multicast groups at startup

  It seems the nlmon packets are limited to actual subscribed mutlicast
  groups.  To get a complete picture of all the nl80211 commands and
  events, it is required that iwmon adds membership to all multicast
  groups that the nl80211 lists.

  This means that the netlink socket used for resolving nl80211 family
  name needs to be kept open and actively processed since it will also
  receive these multicast events.  However the event itself can be dropped
  since the one from nlmon with the proper kernel level timestamps should
  be taken into account.

  An alternative is to fix the netlink_deliver_tap() function in the
  kernel netlink layer to not be affected by the broadcast filtering.

  Priority: Medium
  Complexity: C1

- Add support for writing PCAP files

  The new -w <file> option should allow for writing PCAP files with the
  Linux SLL link type.

  When creating PCAP files using tcpdump a lot of extra information from
  all netlink sockets are written.  This write support should only write
  the information related to nl80211.  However parts from the generic
  netlink control channel from resolving the nl80211 family name must
  be included as well.

  It might be also beneficial to include RTNL messages related to the
  wireless network interfaces.  Currently these are all filtered out.

  Priority: Medium
  Complexity: C2

- Decode the RSNE field

  Properly decode and display the RSNE field.  This is particularly important
  to properly analyze scan results and improve the scan categorization
  functionality.

  Priority: High
  Complexity: C1


Wireless simulator
==================

- Add support for builtin wireless access point emulator

  When creating a pair of mac80211_hwsim radios, allow one to operate as
  access point.  The hwsim utility will emulate the access point on the
  second interface for as long as it is running.  Which means that from
  the first interface it is possible to scan and connect to this access
  point using standard wireless tools (including iwd and iwctl).

  Code for the AP mode can be shared from iwd feature for access point
  operation once that has been implemented.

  Priority: Medium
  Complexity: C8


Wireless daemon
===============

- Building 802.11 authentications management frames

  The other way round, provide a core API to encode an authentication
  or deauthentication frame from a generic structure representing the
  MPDU.

  Priority: High
  Complexity: C2
  Owner: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>

- Handle the relevant logic of the authentication management frames

  When an authentication management frame is received, such frame needs
  to be understood and handled properly.

  Priority: High
  Complexity: C2

- Add support for EAP based authentication and key generation

  Provide full EAP support for enterprise wireless.  However it should be
  possible to build wireless daemon without EAP support.

  It is also intended that this EAP code can be utilized as shared library
  and be beneficial for systemd-networkd for wired authentication.

  Priority: Low
  Complexity: C8

- Create a document to doc describing general architecture and relation
  between different objects.

  Current understanding is that diffrent relation between elements
  looks probably like this:
      Manager->Wiphy->NetDevice->AvailableNetwork

  Wiphy is the actual physical device, NetDevice is the network interface
  and AvailableNetwork is {SSID, security} combo. Each network can have
  a list of BSSs.
  Consider also multi-wifi device scenarios. If user has multiple USB
  WiFi dongles and switches between those cards, all previously configured
  networks should still be available.

  Priority: High
  Complexity: C2

- Implement D-Bus API to Disconnect from an AP

  If we are currently connected to an AP, the Disconnect() method call should
  trigger a disassociation.  If we are in the process of connecting to an AP,
  the connection attempt should be aborted and a disassociation procedure
  should be triggered.

  Priority: High
  Complexity: C2

- Centralize scanning logic and handling into scan.c.

  There can be passive, active, listening (P2P) scanning to handle.
  We need to handle background scan for roaming. Also scheduled scan
  might need to be simulated when hw does not support it.
  All scanning operations should be cancellable.

  Priority: High
  Complexity: C4

- Add utility to create netlink REKEY_DATA attributes

  The REKEY_DATA needs to be uploaded to the driver so that if re-keying is
  triggered by the AP, the TK is updated properly.  Additionally, helper
  function to send NL80211_CMD_SET_REKEY_OFFLOAD command is required.

  Priority: High
  Complexity: C1

- React to NL80211_CMD_SET_REKEY_OFFLOAD events

  This command can be sent to userspace whenever a re-key transaction has
  occurred.  The information contains the Replay Counter.  The Replay Counter
  used by iwd needs to be updated with the new value.

  Priority: Medium
  Complexity: C1

- Add utilities to set Transient Key into the driver

  Once the 4-Way handshake is complete and the TK is generated, it must be sent
  to the kernel so that normal traffic can be encrypted and decrypted
  appropriately.  This seems to be accomplished by NL80211_CMD_NEW_KEY
  and NL80211_CMD_SET_KEY commands.

  Priority: High
  Complexity: C1

- RSN IE Generation for WPA2 Association

  When connecting to a WPA2 Network, we must provide an RSN IE that describes
  our ciphering capabilities.  For WPA2 this generally means CCMP as the
  pairwise cipher.  The same RSN IE is sent during step 2 of the 4-way
  handshake to the Authenticator (AP).  The AP will match RSN IEs received
  in the Association frame and the EAPoL 2/4 frame.  The RSN IE is included
  as part of the Netlink Association Request.

  Information Elements: len 22
  Tag 48: len 20
    01 00 00 0f ac 04 01 00 00 0f ac 04 01 00 00 0f  ................
    ac 02 00 00                                      ....
  Cipher Suites Pairwise: len 4
  CCMP (0x000fac04)
  Cipher Suite Group: CCMP (0x000fac04)
  Control Port: true

  Priority: High
  Complexity: C1

- Take hardware capabilities into account for RSNE generation

  When generating RSNE, take hardware capabilities into account.

  Priority: Medium
  Complexity: C1

- Parse & utilize the 2nd RSNE element in Step 3/4 of the 4-way Handshake

  EAPoL Key Data can contain two RSN elements.  The second element contains
  ciphering settings which were mandated by the AP and could be different
  from settings we provided.  We should parse the 2nd RSNE and determine
  whether the settings are acceptable.  If so, these settings should be
  utilized for the established connection.  Otherwise, connection establishment
  should be aborted.

  Priority: High
  Complexity: C1

- Match 1st RSNE element in Step 3/4 of the 4-way Handshake

  Packet 3/4 EAPoL Key Data should contain at least one RSN Element.  This RSN
  element should be the same as was obtained during the scan or probe of the AP.
  We need to make sure the two RSN Elements match.

  Priority: High
  Complexity: C1

- Extract GTK from Key Data in Step 3/4 of the 4-way Handshake

  GTK is carried inside a KDE.  For KDE format, refer to 802.11 Figure 11-30.
  The GTK KDE format is given in Figure 11-31.  Care must be taken to make sure
  that packets that contain the GTK KDE are encrypted.  If the packet is
  not encrypted, it should be silently dropped.

  Priority: High
  Complexity: C1

- Add unit test for each of the mpdu management frame type

  Currently, only authentication and deauthentication frames have
  proper unit test. Update unit/test-mpdu.c to handle other frames as
  well.

  Priority: Medium
  Complexity: C1


Client
======

- Implement dbus-based command-line client for iwd using ell supporting at least
  the following: Scanning, Connect, Disconnect and agent functionality

  Priority: High
  Complexity: C2