cfg80211_roamed(9)

πŸ“¦ version 7.3.1, in nixpkgs unstable

πŸ’… NAME πŸ’…

cfg80211_roamed β€” the little "hey bestie, we roamed!!" notifier that tells cfg80211 all about it ✨

This one lives in the Kernel API Manual, section 9, and honestly? Iconic. πŸŽ€


✨ SYNOPSIS ✨

void cfg80211_roamed (struct net_device *dev , struct cfg80211_roam_info
*info , gfp_t gfp );

Like… look at her. Three args, no cap. πŸ’…


🫢 ARGUMENTS 🫢

  • dev β€” the network device πŸ’» literally the netdev in question.
  • info β€” all the tea about the new BSS πŸ“ it's a struct cfg80211_roam_info.
  • gfp β€” the allocation flags 🌱 you know the vibe.

🌸 DESCRIPTION 🌸

Okay so here's the situation, bestie. 🧚 This function may be called with the driver passing either the BSSID of the new AP or passing the bss entry to avoid a race in timeout of the bss entry β€” highkey important distinction, don't sleep on it. πŸ‘‘

It should be called by the underlying driver whenever it roamed from one AP to another while connected. fr fr. 🌈

Drivers which have roaming implemented in firmware should pass the bss entry to avoid a race in bss entry timeout β€” because the bss entry of the new AP is seen in the driver, but gets timed out by the time it is accessed in __cfg80211_roamed due to delay in scheduling rdev->event_work. 😭 That's the whole plot twist. The way that scheduling delay just sneaks up on you… πŸ’€

In case of any failures, the reference is released either in cfg80211_roamed or in __cfg80211_romed, Otherwise, it will be released while disconnecting from the current bss. πŸ¦‹ No leaks, we don't do that here. πŸ’œ

🌈 SEE ALSO 🌈

okay so this is the part of the manpage where it just… lists every single friend it has πŸ’– no cap, the whole thing lives in the kernel file ./include/net/cfg80211.h, and every single page below is in section 9 (kernel API). It's giving group-chat roster energy and we are NOT skipping anybody, bestie β€” not one entry, periodt. Let's go 🫢


πŸ¦‹ the header file + the band crew

  • Kernel file ./include/net/cfg80211.h β€” the actual file, the home base, the source of truth 🏠
  • Introduction(9) β€” hi, start here if you're new new.
  • Device registration(9) β€” device registration, iconic behaviour.
  • 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) β€” the OGs: channel flags, channel, rate flags, bss type, privacy, rate. essentials only.
  • struct ieee80211_he_obss_pd(9), struct cfg80211_he_bss_color(9) β€” HE OBSS PD and the HE BSS color, iykyk 🎨
  • 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) β€” the whole capability glow-up timeline: HT β†’ VHT β†’ HE β†’ the EHT MCS/NSS supp β†’ EHT cap β†’ UHR cap. genuinely ate πŸ”₯
  • 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) β€” sband iftype data, EDMG bw config, EDMG, S1G cap, supported band. the band section is serving.
  • _ieee80211_set_sband_iftype_data(9), ieee80211_set_sband_iftype_data(9) β€” yes the first one has a leading underscore and that is NOT a typo, both of them are real, respect both πŸ’…
  • 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) β€” looping + the getters: HE, HE 6GHz, EHT, UHR. get into it bestie.
  • wiphy_read_of_freq_limits(9) β€” reading freq limits, lowkey important.

πŸŽ€ actions & configuration (the long one, buckle up)

  • Actions and configuration(9) β€” yes the chapter heading itself is in the list, that's just how it is.
  • 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) β€” vif params, key params, chan def, TID cfg, TID config (two different ones, do NOT mix them up), FILS AAD, set hw timestamp.
  • chandef 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), cfg80211_chandef_compatible(9), nl80211_chan_width_to_mhz(9), cfg80211_chandef_get_width(9), cfg80211_chandef_valid(9), cfg80211_chandef_usable(9) β€” get type, create, identical, is_edmg, is_s1g, compatible, chan width to mhz, get width, valid, usable.
  • the rest of the chandef-adjacent crew: 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) β€” dfs required / usable / cac time, primary, npca valid, add npca, add dbe, send chandef, max power, s1g pri width, any usable channels. yes all of them. I told you no skipping.
  • enum survey_info_flags(9), struct survey_info(9), struct cfg80211_crypto_settings(9) β€” survey flags, survey info, crypto settings.
  • AP/beacon squad πŸ‘‘ 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) β€” mbssid config, mbssid elems, RNR elems, beacon data, ACL data, FILS discovery, unsol bcast probe resp, S1G short beacon, AP settings, AP update, CSA settings, color change settings. thriving.
  • struct iface_combination_params(9) β€” iface combination params, combo queen ✨
  • station squad: 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) β€” apply mask, sta txpwr, link station params, link station del params, TTLM params, station parameters, station del parameters, station type, check station change.
  • info + stats crew: 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) β€” rate info flags, rate info bw, rate info, bss param flags, sta bss parameters, txq stats, tid stats, link station info, station info.
  • 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) β€” SAR sub specs, SAR specs, SAR freq ranges, SAR capa, get station.
  • mesh/mpath/ocb end of the chapter: 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) β€” monitor flags, mpath info flags, mpath info, wiphy bss param flags, bss parameters, mesh config, mesh setup, OCB setup, txq params.

πŸ” scanning & BSS list handling

  • Scanning and BSS list handling(9) β€” another heading inside the list, yes.
  • 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) β€” ssid, scan info, 6GHz scan params, scan request, match set, sched scan plan, bss select adjust, sched scan request, signal type.
  • BSS crew: struct cfg80211_inform_bss(9), struct cfg80211_bss_ies(9), struct cfg80211_bss(9), ieee80211_bss_get_elem(9), ieee80211_bss_get_ie(9) β€” inform bss, bss ies, bss, get elem, get ie. (both get_elem AND get_ie, don't @ me).
  • connect/assoc crew: 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) β€” auth request, assoc link, ML reconf req, assoc req flags, assoc request, deauth, disassoc, IBSS params, bss selection, connect params, connect params changed.
  • enum wiphy_params_flags(9), struct cfg80211_pmksa(9) β€” wiphy params flags, PMKSA.
  • WoWLAN mood 😴 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) β€” pkt pattern, wowlan tcp, wowlan, coalesce rules, coalesce, wowlan nd match, wowlan nd info, wowlan wakeup.
  • 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) β€” gtk rekey data, update ft ies params, mgmt tx params, dscp exception, dscp range, qos map.

πŸ¦‹ NAN + PMK/PMSR + the ops structs

  • Neighbor Awareness Networking (NAN)(9) β€” yes with the parentheses in the middle, character for character, that's her name.
  • NAN everything: 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) β€” band config, conf, channel, local sched, peer map, peer sched, conf changes, func filter, func.
  • struct cfg80211_pmk_conf(9), struct cfg80211_external_auth_params(9), struct cfg80211_ftm_responder_stats(9) β€” pmk conf, external auth params, FTM responder stats.
  • PMSR crew: 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) β€” ftm result, result, ftm request peer, request peer, request.
  • struct cfg80211_update_owe_info(9), struct mgmt_frame_regs(9), struct cfg80211_ops(9), enum wiphy_flags(9) β€” update owe info, mgmt frame regs, struct cfg80211_ops (the big one, main character energy), wiphy flags.
  • 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) β€” iface limit, iface combination, wowlan support flags, wowlan support, coalesce support.
  • 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) β€” vendor command flags, opmode flag, sta opmode info, wiphy vendor command, iftype ext capab, get iftype ext capa.
  • 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) β€” pmsr capabilities, iftype akm suites, radio cfg, radio freq range, radio, nan flags, nan capa.

πŸ‘‘ the wiphy lifecycle

✨ wireless_dev & the utilities

πŸ”₯ data path helpers

🌸 regulatory enforcement

πŸ’œ notifications, connect/roam & the rest of the roll call

and yes, that last one ends with a literal comma in the source and we are keeping it, it's iconic, it's canon, do not come for the trailing comma πŸ’… the roll call keeps going though, so stay with me…

okay so before we close the book on cfg80211_roamed(9), you have to see the SEE ALSO pile β€” it's genuinely enormous, like a group chat with 64 members where every single one has a strong opinion and a whole manpage of their own. bestie, these are your mutuals now. literally every one of them is reachable as a (9) page, so if you ever get curious mid-read, just go touch grass in another document:

like… look at that roster πŸ’… regulatory stuff, channel switching, NAN girlies, MLO reconf, debugfs, S1G β€” the whole friend group showed up and honestly they ate. screenshot it, bookmark it, send it to your group chat, whatever, because that's the entire neighborhood and you're gonna want it later.


and that's the whole page, bestie β€” you made it to the end and I'm so proud of you 🫢 this one lives over in ./include/net and it's dated October 2026, so if you're reading it in some other timeline, no cap, check your copy. go forth, be the main character of your own wireless stack, and remember: read the flags, respect the flags, slay. πŸŽ€βœ¨

πŸ“¦ where this page comes from