cfg80211_find_ext_ie(9)

okay bestie, this is cfg80211_find_ext_ie(9) from the Kernel API Manual — part 1 of 3, and we are keeping every tiny detail 💖

🌸 NAME 🌸

cfg80211_find_ext_ie — find information element with EID Extension in data ✨

🦋 SYNOPSIS 🦋

const u8 * cfg80211_find_ext_ie (u8 ext_eid , const u8 *ies , int len );

🎀 ARGUMENTS 🎀

• ext_eid — element ID Extension 💅
• ies — data consisting of IEs 🍓
• len — length of data ⭐

💖 RETURN 💖

NULL if the extended element ID could not be found, or if the element is invalid — meaning it claims to be longer than the given data 😭 — or a pointer to the first byte of the requested element, that is the byte containing the element ID 👑

🫶 NOTE 🫶

💀 heads up, bestie: there are no checks on the element length other than having to fit into the given data. no cap.

🌸 SEE ALSO 🌸

okay bestie, this is the part where the page just dumps the entire cfg80211 cinematic universe on you 💀 like, no cap, this is the whole extended family. grab a lil snack, we're doing a tour. every single one of these is a real (9) page, so if you see something you don't know, that's your next hyperfixation 💅

---

✨ the source of truth + the origin story

• Kernel file ./include/net/cfg80211.h
• Introduction(9)
• Device registration(9)

like bestie, that first one is literally the file this whole page is documenting. then the intro and the device-registration chapter. iconic starting lineup fr fr 🫶

🦋 channels, rates & band data (the "what even is a radio" cluster)

• 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)
• 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)
• _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)

that's ht, vht, he, eht, uhr, s1g and edmg all in one list — the way the capability structs just keep multiplying 😭 anyway she's thorough, we respect it 👑

🎀 actions and configuration (the big beefy chapter)

okay this one is lowkey the main character of the SEE ALSO list. deep breath, bestie:

• 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)
• 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)
• 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)
• 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)
• 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)
• 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)
• 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)
• 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)

see what I mean?? chandef this, chandef that — she ate and left no crumbs 💅 the ap settings, csa, color change, station params, sar and the mesh/ocb/txq stuff all live here too. literally the whole configuration multiverse.

🧚 scanning, BSS lists & the wiphy/dev cluster

• 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)
• struct cfg80211_inform_bss(9)
• struct cfg80211_bss_ies(9)
• struct cfg80211_bss(9)
• ieee80211_bss_get_elem(9)
• ieee80211_bss_get_ie(9)
• 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)
• 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)
• 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)
• 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)
• 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)
• 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)
• 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)
• 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)
• 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)
• enum ieee80211_ap_reg_power(9)
• struct wireless_dev(9)
• wdev_priv(9)
• wdev_chandef(9)

scanning → bss → auth/assoc → wowlan → nan → pmsr → the whole wiphy lifecycle → wireless_dev. it's giving "one list to rule them all" and honestly, slay 🔥 wiphy_new, wiphy_register, wiphy_lock, wiphy_unlock, wiphy_unregister, wiphy_free — the full lifecycle right there, no notes 👑

🌈 utility functions & data path helpers

• 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)
• 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)
• struct ieee80211_radiotap_iterator(9)
• ieee80211_get_hdrlen_from_skb(9)
• ieee80211_hdrlen(9)
• ieee80211_get_mesh_hdrlen(9)
• Data path helpers(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)
• 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_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)

not cfg80211_find_ext_elem and cfg80211_find_vendor_elem showing up as siblings of the page you're on right now 🫶 the element-hunting family is all here, plus all the 8023 conversion and header-length besties. so useful, so iconic.

💜 regulatory (do NOT skip, she's important)

• 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 regulatory db functions(9)
• reg_query_regdb_wmm(9)

the regulatory subsystem fr fr. rules, hints, custom regd, cac stuff, and the internal db functions — she's got layers 💅

🍓 scan results, BSS informing & MLME notifications

• cfg80211_scan_done(9)
• cfg80211_sched_scan_results(9)
• cfg80211_sched_scan_stopped(9)
• cfg80211_sched_scan_stopped_locked(9)
• 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)
• 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)

aww look at __cfg80211_get_bss and cfg80211_get_bss right next to each other — the underscore twins 😭 and yes cfg80211_michael_mic_failure is here, we don't talk about it 🙈

⭐ RFkill integration

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

set the hw state, start polling, stop polling. short and sweet, we love a compact chapter 💖

🔥 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)

vendor cmd reply + vendor event stuff. if you're writing a driver with its own secret sauce, this is your aisle 🧚

🎀 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)

alloc reply, reply, alloc event, event. the testmode quartet, together at last 💀

💅 connect / roam / notify — the rest of the notification fam

• 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)
• cfg80211_ready_on_channel(9)
• cfg80211_remain_on_channel_expired(9)
• cfg80211_tx_mgmt_expired(9)
• 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)
• 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)
• cfg80211_cqm_rssi_notify(9)
• cfg80211_cqm_pktloss_notify(9)
• cfg80211_cqm_txe_notify(9)
• cfg80211_cqm_beacon_loss_notify(9)
• __cfg80211_radar_event(9)
• cfg80211_sta_opmode_change_notify(9)
• cfg80211_cac_event(9)
• cfg80211_background_cac_abort(9)
• 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)

connect, roam, port-authorized, disconnected, the whole channel-ready/remain-on-channel gang, sta add/del, rx_mgmt in all its ext/khz flavours, mgmt tx status, control port, the four cfg80211_cqm_* notifiers, radar/cac, gtk rekey, pmksa candidate, spurious frame, unexpected 4addr, probe status, and the obss beacon reporters to close it out. the way this list just keeps going 😭💀 she really said "here's everybody" and meant it.

ngl bestie, that's the whole guest list. every single name, not one dropped — because the SEE ALSO section is sacred and we do not gatekeep 💅✨

---

and that's the extended universe of cross-references, bestie 🌈 no skips, no "you'll figure it out" — every single one is right here, exactly as written, so you can go read the whole friend group:

• cfg80211_reg_check_beaconing(9) — beaconing check behavior 💫
• cfg80211_reg_can_beacon(9) — can we beacon? iconic question
• cfg80211_reg_can_beacon_relax(9) — same question, but relaxed 😌
• cfg80211_ch_switch_notify(9) — channel switch announcement, but make it a notification
• cfg80211_ch_switch_started_notify(9) — "we started" energy
• ieee80211_operating_class_to_band(9) — conversion girlie, band edition
• ieee80211_operating_class_to_chandef(9) — conversion girlie, chandef edition
• ieee80211_chandef_to_operating_class(9) — the reverse, periodt
• ieee80211_chandef_to_khz(9) — numbers to numbers 🔢
• cfg80211_tdls_oper_request(9) — TDLS request moment
• cfg80211_calculate_bitrate(9) — math era ✨
• cfg80211_unregister_wdev(9) — the un-registering one
• cfg80211_register_netdevice(9) — register, netdevice flavour
• cfg80211_unregister_netdevice(9) — its un- counterpart, obviously
• struct cfg80211_ft_event_params(9) — a struct! she has fields 🎀
• cfg80211_ft_event(9) — ft event, slaying
• cfg80211_get_p2p_attr(9) — get that P2P attribute
• ieee80211_ie_split_ric(9) — splitting, but with RIC
• ieee80211_ie_split(9) — the classic split 💅
• ieee80211_fragment_element(9) — fragmenting an element, tiny pieces
• cfg80211_report_wowlan_wakeup(9) — wakeup report, wowlan core
• cfg80211_crit_proto_stopped(9) — crit proto, stopped
• ieee80211_get_num_supported_channels(9) — count the channels 🔥
• cfg80211_check_combinations(9) — combinations check, no cap
• cfg80211_iter_combinations(9) — iterate them instead
• cfg80211_get_radio_idx_by_chan(9) — find the radio index by channel
• cfg80211_stop_link(9) — stop that link 🛑
• cfg80211_stop_iface(9) — and stop that iface
• cfg80211_shutdown_all_interfaces(9) — ALL of them, dramatic much 😭
• wiphy_ext_feature_set(9) — set the ext feature
• wiphy_ext_feature_isset(9) — is it set tho? 👀
• cfg80211_free_nan_func(9) — free it, NAN style
• struct cfg80211_nan_match_params(9) — another struct, another queen 👑
• cfg80211_nan_match(9) — match made in NAN
• cfg80211_nan_func_terminated(9) — terminated, sadly
• cfg80211_nan_sched_update_done(9) — sched update done ✅
• cfg80211_external_auth_request(9) — external auth, requesting
• cfg80211_pmsr_report(9) — PMSR report incoming
• cfg80211_pmsr_complete(9) — PMSR complete, we love a finish
• cfg80211_iftype_allowed(9) — is this iftype allowed? vibe check 😬
• cfg80211_assoc_comeback(9) — assoc comeback, literally the comeback
• cfg80211_update_owe_info_event(9) — OWE info update
• cfg80211_bss_flush(9) — flush it 🚽 (affectionate)
• cfg80211_bss_color_notify(9) — colour notification, aesthetic 🌸
• cfg80211_obss_color_collision_notify(9) — collision! the drama 💀
• cfg80211_color_change_started_notify(9) — colour change: started
• cfg80211_color_change_aborted_notify(9) — colour change: aborted, rip
• cfg80211_color_change_notify(9) — colour change: the main event
• cfg80211_6ghz_power_type(9) — 6GHz power type, futuristic ✨
• cfg80211_links_removed(9) — links removed, gone girl
• struct cfg80211_mlo_reconf_done_data(9) — MLO reconf data struct, she's structured
• cfg80211_mlo_reconf_add_done(9) — reconf add done 🫶
• cfg80211_schedule_channels_check(9) — schedule that channels check
• cfg80211_epcs_changed(9) — EPCS changed, noting it
• cfg80211_next_nan_dw_notif(9) — next NAN DW notification
• cfg80211_nan_cluster_joined(9) — joined the NAN cluster 🎉
• cfg80211_nan_ulw_update(9) — ULW update era
• cfg80211_nan_channel_evac(9) — channel evac, evacuate 💨
• wiphy_locked_debugfs_read(9) — debugfs read, locked edition
• wiphy_locked_debugfs_write(9) — and the write one, matching set
• cfg80211_s1g_get_start_freq_khz(9) — S1G start freq in kHz
• cfg80211_s1g_get_end_freq_khz(9) — S1G end freq in kHz
• cfg80211_s1g_get_primary_sibling(9) — primary sibling, sibling energy 👯
• cfg80211_incumbent_signal_notify(9) — incumbent signal, notified

---

aaaand that's the whole page, bestie, we did it 🎀 this one lives in ./include/net, it's dated October 2026, and it's filed under cfg80211_find_ext_ie(9) — go forth and read the rest of the coven, ily, bye 💜✨🦋