cfg80211_chandef_compatible(9)

📦 version 7.3.1, in nixpkgs unstable

💖 NAME

cfg80211_chandef_compatible — okay so this is the function that does a vibe check on two channel definitions and tells you if they're compatible 💅

Oh and quick thing — this whole page lives in the Kernel API Manual, section 9, and the function is officially cfg80211_chandef_compatible(9), just so you know where you are bestie 🎀

✨ SYNOPSIS

const struct cfg80211_chan_def * cfg80211_chandef_compatible (const struct cfg80211_chan_def *chandef1 , const struct cfg80211_chan_def *chandef2 );

yes the return type is a pointer-to-const and yes it returns one of its own arguments, it's giving "choose your fighter" energy 🔥

🌸 ARGUMENTS

  • chandef1 — the first channel definition, aka contestant number one 🦋 it's a const struct cfg80211_chan_def *, so like, we're looking, not touching.
  • chandef2 — the second channel definition, contestant number two ✨ same deal, const struct cfg80211_chan_def *, read-only main character energy 👑

🦋 RETURN

So here's the tea, and it's honestly so simple it ate:

  • It returns NULL if the given channel definitions are incompatible — that's the "they are NOT compatible, do not pass go" case 💀
  • Otherwise it returns either chandef1 or chandef2 — one of the two you just handed it. Not a copy, not a new struct, literally just one of your own pointers back 🫶
fr fr: the only two outcomes are "NULL, they don't get along" or "here's one of the two you gave me". No third option, no surprises. periodt 💅

✨ SEE ALSO ✨

okay so this is the part where the manpage hands you the entire guest list and it's long — like, "who invited all these people" long 💀 but fr every single one is here, no cap, no skipping. hydrate, stretch, let's go 🫶

First up, the mothership: the kernel file ./include/net/cfg80211.h, plus the starter-pack reads Introduction(9) and Device registration(9). Then the channel-and-band clique, which is basically the main character energy of this whole page: 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), and struct ieee80211_sband_iftype_data(9).

Then the edmg/s1g girlies: enum ieee80211_edmg_bw_config(9), struct ieee80211_edmg(9), struct ieee80211_sta_s1g_cap(9), struct ieee80211_supported_band(9). And the band-filter helper squad, all lowercase and vibey: _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). Wrap that little cluster up with wiphy_read_of_freq_limits(9) and you've survived page one of the list. slay 💅

Next section of the guest list: Actions and configuration(9) — the big-picture chapter — then the parameter structs 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), and struct cfg80211_set_hw_timestamp(9).

Then it's a whole chandef neighbourhood, and honestly it's giving family reunion: cfg80211_get_chandef_type(9), cfg80211_chandef_create(9), cfg80211_chandef_identical(9), cfg80211_chandef_is_edmg(9), cfg80211_chandef_is_s1g(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), and cfg80211_any_usable_channels(9). yes that's the whole family, i counted 😭

Survey and security-ish stuff next: enum survey_info_flags(9), struct survey_info(9), struct cfg80211_crypto_settings(9). Then the beacon/AP crew, which is a lot of structs: 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).

Station-era content, aka the lads: 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). And the rate/reporting icons: 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).

Wrapping this chunk with the SAR + monitoring + mesh + OCB + txq set, because the manpage really said "one more paragraph won't hurt": 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). periodt ✨

Now Scanning and BSS list handling(9) — the chapter, followed by its whole entourage: 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).

Connection-era content incoming: 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).

And the power-save / offload besties: 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). Finish the batch with the QoS trio — struct cfg80211_dscp_exception(9), struct cfg80211_dscp_range(9), struct cfg80211_qos_map(9) — and breathe. 🦋

NAN time, and the manpage is obsessed: Neighbor Awareness Networking (NAN)(9) plus 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 some crossover icons: 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), and struct mgmt_frame_regs(9).

Okay this next cluster is the wiphy wing of the building, and it's big. Start with 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).

Radio config crew: 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). And the accessor/lifecycle lineup, hold on tight: 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).

Work-queue besties, all queued up (pun intended, i'm hilarious): 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). Close it out with enum ieee80211_ap_reg_power(9), struct wireless_dev(9), wdev_priv(9), and wdev_chandef(9). 🔥

Utility functions(9) — the "little helpers" chapter — and its whole squad: 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).

Rates and radiotap and header-length math, oh my: 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) next, and this one's a whole vibe: 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).

Then the element-finder girlies, iykyk: 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), and cfg80211_send_layer2_update(9). 💜

Regulatory enforcement, aka the vibes police: 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).

Then the internals: Internal regulatory db functions(9) and reg_query_regdb_wmm(9). tiny section, big responsibility ✨

And here comes the notification/event firehose, so strap in: 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).

MLME mgmt crew: 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).

RFkill integration(9) and its trio: wiphy_rfkill_set_hw_state_reason(9), wiphy_rfkill_start_polling(9), wiphy_rfkill_stop_polling(9). Vendor commands(9) with 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). And Test mode(9) with cfg80211_testmode_alloc_reply_skb(9), cfg80211_testmode_reply(9), cfg80211_testmode_alloc_event_skb(9), cfg80211_testmode_event(9).

Connect/roam/port-authorization set: 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).

Station info housekeeping: 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 mgmt and control-port icons: 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 and radar and CAC and rekey and PMKSA notifications, aka the "something happened!!" squad: 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).

And the last little batch before we hand off: 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), and struct cfg80211_beaconing_check_config(9). 😭

and bestie… we're literally not even done —

okay that's literally the whole SEE ALSO family, bestie — every single one accounted for, nobody left on read 💖 go click around, they're all doing their own little thing.

so this whole page lives in ./include/net (that's where she's from, 💅) and it's dated October 2026 — mark your calendar, she's a fall girlie. take care of her and she'll take care of your chandefs fr fr 🎀✨

📦 where this page comes from