DATA PATH HELPERS(9)

πŸ“¦ version 7.3.1, in nixpkgs unstable

πŸ’… DATA PATH HELPERS (9) πŸ’…

ok so bestie, welcome to the Kernel API Manual, section 9 β€” yes this is the kernel-adjacent girlie zone, buckle up πŸŽ€


✨ DATA PATH HELPERS ✨

okay so picture this: cfg80211 already comes with a whole pile of generic utilities β€” love that for us, no notes πŸ’… β€” but that's not all she does. nope!

on top of those generic utilities, cfg80211 also ships a set of functions that are literally there to help you implement the data path, specifically for devices that do not do the 802.11/802.3 conversion on the device πŸ¦‹

read that again, because it's the whole vibe of this page:

some devices just do not handle the 802.11/802.3 conversion themselves β€” and these helpers are the ones that step in to help with the data path for exactly those devices ✨

it's giving "the kernel has your back" energy, fr fr 🫢


more parts are coming, so don't go anywhere πŸ‘‘

✨ SEE ALSO ✨

okay bestie, this is the SEE ALSO of all SEE ALSOs πŸ’… like, the kernel doc really just dumped the whole group chat on you. everything down here is another (9) page hanging out in the Kernel file ./include/net/cfg80211.h universe, so grab a snack πŸ“ and let's get into it.


🌸 the fundamentals, bands & caps

start here if you're new, no cap:

Introduction(9), Device registration(9), enum ieee80211_channel_flags(9), struct ieee80211_channel(9), enum ieee80211_rate_flags(9), enum ieee80211_bss_type(9), enum ieee80211_privacy(9), struct ieee80211_rate(9), struct ieee80211_he_obss_pd(9), struct cfg80211_he_bss_color(9)

the rate/cap girlies, they're literally iconic:

struct ieee80211_sta_ht_cap(9), struct ieee80211_sta_vht_cap(9), struct ieee80211_sta_he_cap(9), struct ieee80211_eht_mcs_nss_supp(9), struct ieee80211_sta_eht_cap(9), struct ieee80211_sta_uhr_cap(9), struct ieee80211_sband_iftype_data(9), enum ieee80211_edmg_bw_config(9), struct ieee80211_edmg(9), struct ieee80211_sta_s1g_cap(9), struct ieee80211_supported_band(9)

and the sband iftype helper squad 🫢 (yes the underscore one is right there too, don't @ me):

_ieee80211_set_sband_iftype_data(9), ieee80211_set_sband_iftype_data(9), for_each_sband_iftype_data(9), ieee80211_get_sband_iftype_data(9), ieee80211_get_he_iftype_cap(9), ieee80211_get_he_6ghz_capa(9), ieee80211_get_eht_iftype_cap(9), ieee80211_get_uhr_iftype_cap(9), wiphy_read_of_freq_limits(9)


πŸŽ€ Actions and configuration

the big one. this is the main character section honestly:

Actions and configuration(9), struct vif_params(9), struct key_params(9), struct cfg80211_chan_def(9), struct cfg80211_tid_cfg(9), struct cfg80211_tid_config(9), struct cfg80211_fils_aad(9), struct cfg80211_set_hw_timestamp(9)

channel definition helpers, the chandef girlies ate πŸ”₯:

cfg80211_get_chandef_type(9), cfg80211_chandef_create(9), cfg80211_chandef_identical(9), cfg80211_chandef_is_edmg(9), cfg80211_chandef_is_s1g(9), cfg80211_chandef_compatible(9), nl80211_chan_width_to_mhz(9), cfg80211_chandef_get_width(9), cfg80211_chandef_valid(9), cfg80211_chandef_usable(9)

DFS + the fancy new width stuff:

cfg80211_chandef_dfs_required(9), cfg80211_chandef_dfs_usable(9), cfg80211_chandef_dfs_cac_time(9), cfg80211_chandef_primary(9), cfg80211_chandef_npca_valid(9), cfg80211_chandef_add_npca(9), cfg80211_chandef_add_dbe(9), nl80211_send_chandef(9), ieee80211_chandef_max_power(9), cfg80211_chandef_s1g_pri_width(9), cfg80211_any_usable_channels(9)

survey + crypto + the beacon-y structs:

enum survey_info_flags(9), struct survey_info(9), struct cfg80211_crypto_settings(9), struct cfg80211_mbssid_config(9), struct cfg80211_mbssid_elems(9), struct cfg80211_rnr_elems(9), struct cfg80211_beacon_data(9), struct cfg80211_acl_data(9), struct cfg80211_fils_discovery(9), struct cfg80211_unsol_bcast_probe_resp(9), struct cfg80211_s1g_short_beacon(9)

AP settings & friends, lowkey a lot of them:

struct cfg80211_ap_settings(9), struct cfg80211_ap_update(9), struct cfg80211_csa_settings(9), struct cfg80211_color_change_settings(9), struct iface_combination_params(9)

stations!! this whole crew:

enum station_parameters_apply_mask(9), struct sta_txpwr(9), struct link_station_parameters(9), struct link_station_del_parameters(9), struct cfg80211_ttlm_params(9), struct station_parameters(9), struct station_del_parameters(9), enum cfg80211_station_type(9), cfg80211_check_station_change(9)

rate info + bss params + tid stats:

enum rate_info_flags(9), enum rate_info_bw(9), struct rate_info(9), enum bss_param_flags(9), struct sta_bss_parameters(9), struct cfg80211_txq_stats(9), struct cfg80211_tid_stats(9), struct link_station_info(9), struct station_info(9)

SAR stuff (power limits bestie, be responsible ✨) and the rest:

struct cfg80211_sar_sub_specs(9), struct cfg80211_sar_specs(9), struct cfg80211_sar_freq_ranges(9), struct cfg80211_sar_capa(9), cfg80211_get_station(9), enum monitor_flags(9), enum mpath_info_flags(9), struct mpath_info(9), enum wiphy_bss_param_flags(9), struct bss_parameters(9), struct mesh_config(9), struct mesh_setup(9), struct ocb_setup(9), struct ieee80211_txq_params(9)


πŸ” Scanning and BSS list handling

scanning era 🌈:

Scanning and BSS list handling(9), struct cfg80211_ssid(9), struct cfg80211_scan_info(9), struct cfg80211_scan_6ghz_params(9), struct cfg80211_scan_request(9), struct cfg80211_match_set(9), struct cfg80211_sched_scan_plan(9), struct cfg80211_bss_select_adjust(9), struct cfg80211_sched_scan_request(9), enum cfg80211_signal_type(9)

BSS reporting + lookup:

struct cfg80211_inform_bss(9), struct cfg80211_bss_ies(9), struct cfg80211_bss(9), ieee80211_bss_get_elem(9), ieee80211_bss_get_ie(9)

auth / assoc / deauth / disassoc β€” the whole situationship πŸ’€:

struct cfg80211_auth_request(9), struct cfg80211_assoc_link(9), struct cfg80211_ml_reconf_req(9), enum cfg80211_assoc_req_flags(9), struct cfg80211_assoc_request(9), struct cfg80211_deauth_request(9), struct cfg80211_disassoc_request(9)

ibss + connect + power save stuff:

struct cfg80211_ibss_params(9), struct cfg80211_bss_selection(9), struct cfg80211_connect_params(9), enum cfg80211_connect_params_changed(9), enum wiphy_params_flags(9), struct cfg80211_pmksa(9), struct cfg80211_pkt_pattern(9), struct cfg80211_wowlan_tcp(9)

wowlan & coalesce & wakeup (sleepy time 😴):

struct cfg80211_wowlan(9), struct cfg80211_coalesce_rules(9), struct cfg80211_coalesce(9), struct cfg80211_wowlan_nd_match(9), struct cfg80211_wowlan_nd_info(9), struct cfg80211_wowlan_wakeup(9), struct cfg80211_gtk_rekey_data(9), struct cfg80211_update_ft_ies_params(9), struct cfg80211_mgmt_tx_params(9), struct cfg80211_dscp_exception(9), struct cfg80211_dscp_range(9), struct cfg80211_qos_map(9)


πŸ’œ NAN, PMSR, auth & frame regs

NAN bestie!! πŸ¦‹

Neighbor Awareness Networking (NAN)(9), struct cfg80211_nan_band_config(9), struct cfg80211_nan_conf(9), struct cfg80211_nan_channel(9), struct cfg80211_nan_local_sched(9), struct cfg80211_nan_peer_map(9), struct cfg80211_nan_peer_sched(9), enum cfg80211_nan_conf_changes(9), struct cfg80211_nan_func_filter(9), struct cfg80211_nan_func(9)

then the pmk / external auth / ranging crowd:

struct cfg80211_pmk_conf(9), struct cfg80211_external_auth_params(9), struct cfg80211_ftm_responder_stats(9), struct cfg80211_pmsr_ftm_result(9), struct cfg80211_pmsr_result(9), struct cfg80211_pmsr_ftm_request_peer(9), struct cfg80211_pmsr_request_peer(9), struct cfg80211_pmsr_request(9), struct cfg80211_update_owe_info(9), struct mgmt_frame_regs(9)


πŸ‘‘ ops & wiphy (the whole kingdom)

struct cfg80211_ops(9), enum wiphy_flags(9), struct ieee80211_iface_limit(9), struct ieee80211_iface_combination(9), enum wiphy_wowlan_support_flags(9), struct wiphy_wowlan_support(9), struct wiphy_coalesce_support(9), enum wiphy_vendor_command_flags(9), enum wiphy_opmode_flag(9), struct sta_opmode_info(9)

vendor command + iftype capa + radio cfg:

struct wiphy_vendor_command(9), struct wiphy_iftype_ext_capab(9), cfg80211_get_iftype_ext_capa(9), struct cfg80211_pmsr_capabilities(9), struct wiphy_iftype_akm_suites(9), struct wiphy_radio_cfg(9), struct wiphy_radio_freq_range(9), struct wiphy_radio(9), enum wiphy_nan_flags(9), struct wiphy_nan_capa(9)

the wiphy lifecycle, A to Z slay:

struct wiphy(9), wiphy_priv(9), priv_to_wiphy(9), set_wiphy_dev(9), wiphy_dev(9), wiphy_name(9), wiphy_new_nm(9), wiphy_new(9), wiphy_register(9), rcu_dereference_wiphy(9), wiphy_dereference(9), get_wiphy_regdom(9), wiphy_unregister(9), wiphy_free(9)

locking + the work queue family (there are SO many of these, obsessed):

wiphy_lock(9), wiphy_unlock(9), wiphy_work_queue(9), wiphy_work_cancel(9), wiphy_work_flush(9), wiphy_delayed_work_queue(9), wiphy_delayed_work_cancel(9), wiphy_delayed_work_flush(9), wiphy_delayed_work_pending(9), wiphy_hrtimer_work_queue(9), wiphy_hrtimer_work_cancel(9), wiphy_hrtimer_work_flush(9), wiphy_hrtimer_work_pending(9)

and the wireless_dev trio:

enum ieee80211_ap_reg_power(9), struct wireless_dev(9), wdev_priv(9), wdev_chandef(9)


πŸ› οΈ Utility functions

the helpful little guys πŸ’–:

Utility functions(9), ieee80211_channel_equal(9), ieee80211_channel_to_khz(9), ieee80211_channel_to_freq_khz(9), ieee80211_channel_to_frequency(9), ieee80211_freq_khz_to_channel(9), ieee80211_frequency_to_channel(9), ieee80211_get_channel_khz(9), ieee80211_get_channel(9), cfg80211_channel_is_psc(9)

radio/chandef validation + rates:

ieee80211_radio_freq_range_valid(9), cfg80211_radio_chandef_valid(9), cfg80211_wdev_channel_allowed(9), ieee80211_get_response_rate(9), ieee80211_mandatory_rates(9)

radiotap + header length + the 8023 conversions (the way these just keep going 😭):

struct ieee80211_radiotap_iterator(9), ieee80211_get_hdrlen_from_skb(9), ieee80211_hdrlen(9), ieee80211_get_mesh_hdrlen(9), ieee80211_data_to_8023_exthdr(9), ieee80211_data_to_8023(9), ieee80211_is_valid_amsdu(9), ieee80211_amsdu_to_8023s(9), ieee80211_get_8023_tunnel_proto(9), ieee80211_strip_8023_mesh_hdr(9), cfg80211_classify8021d(9)

element / IE finders, one per flavour, no notes:

cfg80211_find_elem_match(9), cfg80211_find_ie_match(9), cfg80211_find_elem(9), cfg80211_find_ie(9), cfg80211_find_ext_elem(9), cfg80211_find_ext_ie(9), cfg80211_find_vendor_elem(9), cfg80211_find_vendor_ie(9), enum cfg80211_rnr_iter_ret(9), cfg80211_iter_rnr(9), cfg80211_defragment_element(9), cfg80211_send_layer2_update(9)


Regulatory enforcement infrastructure(9), regulatory_hint(9), regulatory_set_wiphy_regd(9), regulatory_set_wiphy_regd_sync(9), wiphy_apply_custom_regulatory(9), freq_reg_info(9), reg_initiator_name(9), regulatory_pre_cac_allowed(9)

internal db stuff:

Internal regulatory db functions(9), reg_query_regdb_wmm(9)


πŸ“¨ notifications: scan, BSS, mlme

cfg80211_scan_done(9), cfg80211_sched_scan_results(9), cfg80211_sched_scan_stopped(9), cfg80211_sched_scan_stopped_locked(9)

BSS informing + lookups:

cfg80211_inform_bss_frame_data(9), cfg80211_gen_new_bssid(9), cfg80211_is_element_inherited(9), cfg80211_merge_profile(9), enum cfg80211_bss_frame_type(9), cfg80211_get_ies_channel_number(9), cfg80211_ssid_eq(9), cfg80211_inform_bss_data(9), __cfg80211_get_bss(9), cfg80211_get_bss(9), cfg80211_ref_bss(9), cfg80211_put_bss(9), cfg80211_unlink_bss(9), cfg80211_bss_iter(9)

mlme events, lit rally all of them:

cfg80211_rx_mlme_mgmt(9), cfg80211_auth_timeout(9), struct cfg80211_rx_assoc_resp_data(9), cfg80211_rx_assoc_resp(9), struct cfg80211_assoc_failure(9), cfg80211_assoc_failure(9), cfg80211_tx_mlme_mgmt(9), cfg80211_rx_unprot_mlme_mgmt(9), cfg80211_michael_mic_failure(9), cfg80211_ibss_joined(9), cfg80211_notify_new_peer_candidate(9)


πŸ“‘ RFkill integration, Vendor commands, Test mode

rfkill trio:

RFkill integration(9), wiphy_rfkill_set_hw_state_reason(9), wiphy_rfkill_start_polling(9), wiphy_rfkill_stop_polling(9)

vendor commands 🫢:

Vendor commands(9), cfg80211_vendor_cmd_alloc_reply_skb(9), cfg80211_vendor_cmd_reply(9), cfg80211_vendor_cmd_get_sender(9), cfg80211_vendor_event_alloc(9), cfg80211_vendor_event_alloc_ucast(9), cfg80211_vendor_event(9)

test mode:

Test mode(9), cfg80211_testmode_alloc_reply_skb(9), cfg80211_testmode_reply(9), cfg80211_testmode_alloc_event_skb(9), cfg80211_testmode_event(9)


πŸ”₯ connect / disconnect / roaming / mgmt frame reporting

connect resp era:

struct cfg80211_fils_resp_params(9), struct cfg80211_connect_resp_params(9), cfg80211_connect_done(9), cfg80211_connect_bss(9), cfg80211_connect_result(9), cfg80211_connect_timeout(9), struct cfg80211_roam_info(9), cfg80211_roamed(9), cfg80211_port_authorized(9), cfg80211_disconnected(9)

remain-on-channel + tx mgmt expiry:

cfg80211_ready_on_channel(9), cfg80211_remain_on_channel_expired(9), cfg80211_tx_mgmt_expired(9)

station info + sta add/del:

cfg80211_sinfo_alloc_tid_stats(9), cfg80211_link_sinfo_alloc_tid_stats(9), cfg80211_sinfo_release_content(9), cfg80211_new_sta(9), cfg80211_del_sta_sinfo(9), cfg80211_del_sta(9), cfg80211_conn_failed(9)

rx/tx info & mgmt status:

struct cfg80211_rx_info(9), cfg80211_rx_mgmt_ext(9), cfg80211_rx_mgmt_khz(9), cfg80211_rx_mgmt(9), struct cfg80211_tx_status(9), cfg80211_mgmt_tx_status_ext(9), cfg80211_mgmt_tx_status(9), cfg80211_control_port_tx_status(9), cfg80211_rx_control_port(9)

cqm notifications (rssi, packet loss, txe, beacon loss):

cfg80211_cqm_rssi_notify(9), cfg80211_cqm_pktloss_notify(9), cfg80211_cqm_txe_notify(9), cfg80211_cqm_beacon_loss_notify(9)

radar / cac / opmode:

__cfg80211_radar_event(9), cfg80211_sta_opmode_change_notify(9), cfg80211_cac_event(9), cfg80211_background_cac_abort(9)

the last little fam 🧚:

cfg80211_gtk_rekey_notify(9), cfg80211_pmksa_candidate_notify(9), cfg80211_rx_spurious_frame(9), cfg80211_rx_unexpected_4addr_frame(9), cfg80211_probe_status(9), cfg80211_report_obss_beacon_khz(9), cfg80211_report_obss_beacon(9), struct cfg80211_beaconing_check_config(9),

Okay so the reference list keeps going, bestie β€” buckle up, we're in the cross-reference era of this page πŸ’…

That's the regulatory + channel-switch + IE-parsing chunk, and honestly it's giving "i have a function for literally everything" energy ✨ if you need a band, a chandef, a bitrate, or a whole netdevice torn down, the list has you covered fr fr.

The NAN cluster, the colour-change notifications, and the MLO reconf crowd all showing up together? main character energy, no cap πŸ‘‘ notice how the notify-flavoured ones come in little families (started / aborted / plain old notify) β€” that's just how the kernel likes to gossip about state changes, iykyk.

More NAN (discovery windows, cluster joins, ULW updates, channel evacuation πŸ’€), the debugfs pair (read and write, matching set, we love symmetry 🫢), the S1G frequency helpers, and finally cfg80211_incumbent_signal_notify(9) bringing up the rear.

That's the whole list, bestie β€” every single reference, nothing cut, nothing merged. If you're grepping for one of these and it's not here, it's not in the original either, so don't come for me 😭

And that's a wrap on the whole page! 🌸 This little beauty lives under ./include/net, it's dated October 2026, and it goes by Data path helpers(9) β€” slay, ate, periodt πŸŽ€ Now go forth and read the actual functions, you absolute icon πŸ’–πŸ§š

πŸ“¦ where this page comes from