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

About cfg80211

cfg80211 is the Linux 802.11 configuration API. cfg80211 replaces Wireless-Extensions. nl80211 is used to configure a cfg80211 device. Wext is now in maintenance mode, no new features will be added to it, we'll only fix bugs for it. cfg80211 is now feature-par complete with wireless-extensions.

All new Linux wireless drivers should be written targeting either cfg80211 for fullmac devices or mac80211 for softmac devices.

Writing cfg80211 drivers

We now have a few cfg80211 drivers, a good example of a full cfg80211 drivers is the Atheros ath6kl driver. Instead of writing wext ioctls you now write cfg80211 operation callbacks and fill in the wiphy struct to indicate to cfg80211 its device capabilities.

As an example here is ath6kl's cfg80211_ops:

static struct cfg80211_ops ath6kl_cfg80211_ops = {
        .add_virtual_intf = ath6kl_cfg80211_add_iface,
        .del_virtual_intf = ath6kl_cfg80211_del_iface,
        .change_virtual_intf = ath6kl_cfg80211_change_iface,
        .scan = ath6kl_cfg80211_scan,
        .connect = ath6kl_cfg80211_connect,
        .disconnect = ath6kl_cfg80211_disconnect,
        .add_key = ath6kl_cfg80211_add_key,
        .get_key = ath6kl_cfg80211_get_key,
        .del_key = ath6kl_cfg80211_del_key,
        .set_default_key = ath6kl_cfg80211_set_default_key,
        .set_wiphy_params = ath6kl_cfg80211_set_wiphy_params,
        .set_tx_power = ath6kl_cfg80211_set_txpower,
        .get_tx_power = ath6kl_cfg80211_get_txpower,
        .set_power_mgmt = ath6kl_cfg80211_set_power_mgmt,
        .join_ibss = ath6kl_cfg80211_join_ibss,
        .leave_ibss = ath6kl_cfg80211_leave_ibss,
        .get_station = ath6kl_get_station,
        .set_pmksa = ath6kl_set_pmksa,
        .del_pmksa = ath6kl_del_pmksa,
        .flush_pmksa = ath6kl_flush_pmksa,
#ifdef CONFIG_PM
        .suspend = __ath6kl_cfg80211_suspend,
        .resume = __ath6kl_cfg80211_resume,
        .start_ap = ath6kl_start_ap,
        .change_beacon = ath6kl_change_beacon,
        .stop_ap = ath6kl_stop_ap,
        .del_station = ath6kl_del_station,
        .change_station = ath6kl_change_station,
        .remain_on_channel = ath6kl_remain_on_channel,
        .cancel_remain_on_channel = ath6kl_cancel_remain_on_channel,
        .mgmt_tx = ath6kl_mgmt_tx,
        .mgmt_frame_register = ath6kl_mgmt_frame_register,
        .sched_scan_start = ath6kl_cfg80211_sscan_start,
        .sched_scan_stop = ath6kl_cfg80211_sscan_stop,

Then you allocate the wiphy by specifying the cfg80211 ops and fill the wiphy.

For more details refer to cfg80211.h and as an example driver you can read ath6kl.


Linux wireless regulatory documentation:

other documentation

cfg80211 files and kernel docs

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