STRUCT IEEE80211_IFACE_COMBINATION(9)

📦 version 7.3.1, in nixpkgs unstable

👑 struct ieee80211_iface_combination(9) — the Kernel API Manual, bestie edition 💖

okay so this is struct ieee80211_iface_combination from the kernel API manual, section 9, and honestly? it's lowkey the blueprint for "which interfaces can vibe together at the same time" ✨ buckle up.

🌸 NAME 🌸

struct ieee80211_iface_combination — possible interface combination 🫶

✨ SYNOPSIS ✨

struct ieee80211_iface_combination {
    const struct ieee80211_iface_limit *limits;
    u32 num_different_channels;
    u16 max_interfaces;
    u8 n_limits;
    bool beacon_int_infra_match;
    u8 radar_detect_widths;
    u8 radar_detect_regions;
    u32 beacon_int_min_gcd;
};

that's the whole squad right there, no cap 💅

🎀 MEMBERS 🎀

  • limits — the limits for the given interface types. like, the rules of who's allowed in 💖
  • num_different_channels — can use up to this many different channels. that's the ceiling, bestie 📶
  • max_interfaces — maximum number of interfaces in total allowed in this group 🔥
  • n_limits — number of limitations 🔢
  • beacon_int_infra_match — in this combination, the beacon intervals between infrastructure and AP types must match. it's required only in special cases, so don't stress about it 99% of the time 🙈
  • radar_detect_widths — bitmap of channel widths supported for radar detection 📡
  • radar_detect_regions — bitmap of regions supported for radar detection 🌍
  • beacon_int_min_gcd — this interface combination supports different beacon intervals.
and here's the fine print on that last one, because it matters: = 0 → all beacon intervals for different interface must be same. > 0 → any beacon interval for the interface part of this combination AND GCD of all beacon intervals from beaconing interfaces of this combination must be greater or equal to this value.

like, the math is mathing and you can't skip it 😭

🦋 DESCRIPTION 🦋

so with this structure the driver can describe which interface combinations it supports concurrently. that's the whole point, iconic behavior honestly 👑

when set in a struct wiphy_radio, the combinations refer to combinations of interfaces currently active on that radio 📻✨

🌈 EXAMPLES 🌈

1️⃣ Allow #STA <= 1, #AP <= 1, matching BI, channels = 1, 2 total:

struct ieee80211_iface_limit limits1[] = {
        { .max = 1, .types = BIT(NL80211_IFTYPE_STATION), },
        { .max = 1, .types = BIT(NL80211_IFTYPE_AP), },
};
struct ieee80211_iface_combination combination1 = {
        .limits = limits1,
        .n_limits = ARRAY_SIZE(limits1),
        .max_interfaces = 2,
        .beacon_int_infra_match = true,
};

2️⃣ Allow #{AP, P2P-GO} <= 8, channels = 1, 8 total:

struct ieee80211_iface_limit limits2[] = {
        { .max = 8, .types = BIT(NL80211_IFTYPE_AP) |
                             BIT(NL80211_IFTYPE_P2P_GO), },
};
struct ieee80211_iface_combination combination2 = {
        .limits = limits2,
        .n_limits = ARRAY_SIZE(limits2),
        .max_interfaces = 8,
        .num_different_channels = 1,
};

3️⃣ Allow #STA <= 1, #{P2P-client,P2P-GO} <= 3 on two channels, 4 total.

this allows for an infrastructure connection and three P2P connections 🫶

struct ieee80211_iface_limit limits3[] = {
        { .max = 1, .types = BIT(NL80211_IFTYPE_STATION), },
        { .max = 3, .types = BIT(NL80211_IFTYPE_P2P_GO) |
                             BIT(NL80211_IFTYPE_P2P_CLIENT), },
};
struct ieee80211_iface_combination combination3 = {
        .limits = limits3,
        .n_limits = ARRAY_SIZE(limits3),
        .max_interfaces = 4,
        .num_different_channels = 2,
};

✨ part 1 done, there's more coming so don't go anywhere 💜

🌸 SEE ALSO 🌸

okay bestie, this is the SEE ALSO section and it is literally the entire cfg80211 extended universe in one group chat. No cap, it’s a lot. The source of truth starts at Kernel file ./include/net/cfg80211.h, and then the manual name-drops everyone: 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), 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), and wiphy_read_of_freq_limits(9). iconic behavior, honestly 💅

next up is the whole “Actions and configuration” corner of the party: 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), and cfg80211_any_usable_channels(9). it’s giving “the chandef cinematic universe” fr fr 🎀

then we get the survey / crypto / beacon / AP / station besties: 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), and struct ieee80211_txq_params(9). so many structs, so little time 😭

and now the scanning / BSS list handling section rolls in like it owns the place: 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), and struct cfg80211_qos_map(9). the way this list just keeps going is honestly main character energy ✨

then we hit the NAN era, which is its own vibe: 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), and struct mgmt_frame_regs(9). NAN girlies, we see you 🦋

the ops / wiphy / iface-combination crowd is next and they are so important: struct cfg80211_ops(9), enum wiphy_flags(9), struct ieee80211_iface_limit(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), and struct wiphy(9). periodt 💜

then comes the wiphy lifecycle and workqueue girlies: 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), and wdev_chandef(9). lock it, queue it, flush it, slay it 💅

utility functions + radiotap + data path helpers are all up in here too: 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_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). find that IE, bestie 🔍

regulatory enforcement and the internal regulatory db functions are also in the group chat: 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), and reg_query_regdb_wmm(9). regulatory girlies stay booked and busy 🌈

and finally, the last big stretch of the SEE ALSO scroll: 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), RFkill integration(9), wiphy_rfkill_set_hw_state_reason(9), wiphy_rfkill_start_polling(9), wiphy_rfkill_stop_polling(9), 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(9), cfg80211_testmode_alloc_reply_skb(9), cfg80211_testmode_reply(9), cfg80211_testmode_alloc_event_skb(9), cfg80211_testmode_event(9), 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), and struct cfg80211_beaconing_check_config(9). that’s the whole SEE ALSO roster, bestie — every single one is here, no skips, no cap 🫶

okay bestie, real talk: the SEE ALSO section is basically a group chat and everyone in it is texting at once 💬✨ we already met the headliners, so here's the rest of the squad, in the order they showed up, and yes i'm listing every single one because nobody gets left on read 🙌

see? not even halfway and we're already thriving 💅 bestie i need you to keep scrolling, the vibe check isn't over 🫶

the way this list just refuses to end 😭 iconic honestly, she's a maximalist and we respect it 🎀

and that's the WHOLE group chat, no cap, nobody got ghosted 💖 like if you actually read all of those you're lowkey the main character of kernel wifi documentation, periodt ✨

and that's a wrap on this whole page, bestie!! 🌈 the source it lives under is ./include/net, it's dated October 2026, and the page itself is struct ieee8..._combination(9) — go forth and be obsessed with it 🦋💜

📦 where this page comes from