NOTE: this page is for archival only, see the note at the end of the page.

TableOfContents()

mainline issues

mac80211

  • hide (or get rid of) master dev to have stable userland interface
  • compat: handle reassociation when the sta is out of range for a moment and then comes back

cfg80211

  • rename struct wiphy to struct phy80211?

mac80211

Most important issues

  • Add callbacks for devices with advanced firmware.
  • Need to stop TX/RX when a radar is detected for the duration of scan for a new channel. (Partially solved by PRISM2_PARAM_RADIO_ENABLED.) [reported by Jouni Malinen]
  • rename ieee80211_local (e.g.: rename ieee80211_hw to ieee80211_dev and ieee80211_local to ieee80211_hw)

Other issues

  • Add a ieee80211_resume(hw) function that drivers can call when they resume. It should

    • call set_key for each key that was uploaded to hardware
    • reconfigure hardware (channel etc)
    • ...?

crypto

  • Embed ieee80211_key_conf into ieee80211_key so just one memcpy can be used in ieee80211_key_data2conf().

  • split out frame crypto stuff into modules like in-kernel ieee80211 does. I'm not sure any more this is worth it though since the actual algorithms (i.e. most code) can be modular anyway – JohannesBerg DateTime(2007-04-06T09:48:48Z)

  • Calls to ieee80211_key_threshold_notify are needless in some places. When the interface is in STA mode, a lot of operations is performed and the result is thrown away.

scanning

  • Rework background scanning to work without background scan callback. [suggested by Johannes Berg]

core

misc

  • Export information about softmac/fullmac type of the hardware to userspace. [suggested by Jouni Malinen] (maybe export capabilities instead?)

  • Easier handling of configuration requests (ieee80211_hw->config()). In the current implementation, driver has no way to find out which parameter is being set; setting all parameters on every call to config() is obviously not a good idea.

  • struct ieee80211_tx_queue_stats is strange (why not to use ieee80211_tx_queue_stats_data directly?)
  • Kicking DMA on the last fragment only (?) [suggested by Ivo van Doorn]
  • Why there is a beacon_update() handler? Maybe it would be easier for the driver to be allowed to call ieee80211_beacon_get() even in IBSS mode.
  • Add functions that will tell the driver which rates and modulations are allowed. Some cards need to tell their firmware about it.
  • Move ETH_P_PAE from ieee80211_i.h to linux/if_ether.h.
  • Make IEEE80211_FRAGMENT_MAX configurable (preferably at run-time).
  • Alter LL_MAX_HEADER constant.
  • Fix the race in PS status update (see TODO in ieee80211_tx_status()).
  • Do not misuse iwpriv for generic ioctls (i.e. do not use iwpriv ioctls in the stack at all).
  • Remove ioctl (add_iface, WPA) compatibility stuff.
  • Move ieee80211_get_hdrlen* from ieee80211.c to ieee80211_proto.c.
  • Sort out function definitions in ieee80211_i.h (they are at two different places in the file now).
  • Split ieee80211.c into several files.
  • ieee80211_if_conf should be a part of ieee80211_sub_if_data
  • In case of STA or IBSS, after a change of SSID or generic_element, ieee80211_if_conf should be called.

  • Clean up headers mess (http://www.spinics.net/lists/netdev/msg12124.html). [suggested by Johannes Berg]

  • Get rid of bitfields (partially done, still left: ieee80211_txrx_data, ieee80211_tx_packet_data, ieee80211_tx_stored_packet, ieee80211_passive_scan, ieee80211_if_sta and ieee80211_sub_if_data). [suggested by Jeff Garzik]

  • #ifdef out wpa_test variable (but do not add #ifdefs into ifs).
  • Allow set_key to return -ENOBUFS to indicate there is no more room for keys and do sw encryption for this STA then. [suggested by Michael Buesch]
  • ieee80211_msg_type, ieee80211_phytype and ieee80211_ssi_type should be in capitals (I think they can be removed once we move to radiotap)
  • Allow "even-harder-monitor" mode - i.e. all frames (including those with a bad FCS) are received. That means introducing a new "not_checksummed" flag for non-monitor interfaces to operate simultaneously.
  • For research: do the same with incorrect PLCP checksums?

qdisc bugs

  • can't put the ieee80211 qdisc back on while the device is running

From Patrick McHardy:

  • classify_1d doesn't care about tc_classify return values. tc_classify may decide to steal packets, drop them, etc. In case of stolen packets this causes use-after-free, otherwise just malfunctions.

  • classify_1d returns res.class if it is != -1, which can never happen (except with an empty classifier list because of the explicit initialization, but you should check the return code) since ->get() and ->bind_tcf() both return 0 for invalid classes and the classid otherwise. There's also an off-by-one, classids start at one, so it should return res.class - 1 (or better res.classid - 1, which is meant to be a numerical identifier).

Considering that it is possibly and may be desirable to attach a different qdisc than the built-in multiband qdisc, it might also make sense to split the 80211 specific classification in a seperate classifier module to allow simple classification of management traffic with other qdiscs.

Library functions we should add

  • PLCP Length calculation
  • Functions to fill modes/rates for B, BG, and ABG.
  • TKIP key mixing functions (work in progress by mbuesch)

Optimizations

  • ieee80211_get_hdrlen and ieee80211_is_eapol are called very often.
  • Inline ieee80211_get_bssid()?
  • All frames go through all of decryption functions. It should be possible to know what to expect and only pass it through those functions that are needed. [suggested by Johannes Berg]
  • Recognition of device incoming frame belongs to can be made much smarter and faster.
  • When one packet is dumped through several interfaces, some operations can be performed just once (e.g. searching for the key, sometimes decrypting, defragmentation etc.).
  • Add #ifdef's for not compiling AP stuff. [suggested by Jouni Malinen]
  • Move fragmentation etc. into 802.11 qdisc. [suggested by Simon Barber]
  • Try to switch from sw crypto to hw when there was no more room for STA keys in the hardware and one STA disassociates (so there is possibly a room now). [suggested by Johannes and Michael]
  • dynamically registered tx/rx handlers (and split them out from ieee80211.c)

Coding style

  • remove forward declarations

drivers

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