nl80211_send_chandef(9)

📦 version 7.3.1, in nixpkgs unstable

💅 nl80211_send_chandef 💅

okay so bestie, welcome to nl80211_send_chandef(9) — yes that's the section 9, Kernel API Manual vibe, we're in the deep kernel end now 🫶. This little icon is literally the one that sends the channel definition, and honestly? she's doing the most with very little. let's get into it ✨

✨ NAME ✨

nl80211_send_chandef — sends the channel definition 💖

like, that's her whole job. that's the assignment and she ate.

🌸 SYNOPSIS 🌸

int nl80211_send_chandef (struct sk_buff *msg , const struct
       cfg80211_chan_def *chandef );

so she takes two things and gives you back an int. no cap, that's it. look at her being all struct sk_buff *msg and const struct cfg80211_chan_def *chandef — main character energy fr fr 👑

🎀 ARGUMENTS 🎀

  • msg — the msg to send channel definition 💌 like this is the sk_buff she's gonna tuck the channel definition into. it's giving delivery service, it's giving "I got you bestie" 🦋
  • chandef — the channel definition to check 👀 yes she's const, yes she's a struct cfg80211_chan_def *, and yes she's the star of the show. this is the actual channel definition getting the vibe check 🌈

⭐ RETURN ⭐

  • 0 if sent the channel definition to msg — slay, success, we love a clean zero 💅✨
  • < 0 on error — not the vibe 😭 something went wrong, she's negative, we're in our flop era (derogatory)
lowkey important bestie: zero means it made it into msg, anything less than zero means nope, error, do not pass go 🙈 keep an eye on that return value iykyk

part 1 done, more coming — don't go anywhere 🧚💜

✨ SEE ALSO ✨

okay so this section is literally the whole friend group 💅 — every single thing cfg80211 wants you to go read next. Grab a snack, bestie, because it's long. Ngl it's giving "the entire syllabus on one page" energy but every single one of these is a real cross-reference and we are NOT skipping any, periodt.

  • ./include/net/cfg80211.h — this is the kernel file where it all lives fr fr. Start here if you want the source-of-truth vibes.
  • Introduction(9) — the intro page, the little orientation tour 🫶
  • Device registration(9) — how you register a device, iconic behaviour

🦋 the bands, channels & rates girlies

okay this whole cluster is about the radio side of things — channels, rates, HT/VHT/HE/EHT/UHR caps, and all that delicious capability data. If you're messing with what a band can, like, do, this is your squad ✨

🎀 Actions and configuration

this is the big one, bestie. chandef everywhere. channel definitions, TID configs, beacon data, AP settings, station params, SAR, mesh, OCB — it's giving main character energy and honestly it earned it 👑

🔥 Scanning and BSS list handling

the "finding wifi and remembering it" era 🌸 scan requests, scheduled scans, BSS entries, auth/assoc/deauth/disassoc, IBSS, connect params, plus all the WoWLAN + coalesce + QoS goodies. Obsessed with how much is in here ngl.

  • 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) + the auth crew

NAN besties rise 🧚 — bands, channels, schedules, peer maps, filters, funcs. Then PMK, external auth, FTM responder stats, PMSR, OWE, and management frame regs. it's giving "so many moving parts" and honestly same.

  • 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)

👑 the wiphy era (ops, flags, iface combos, radios)

the driver-side royalty 💅 — cfg80211_ops, wiphy flags, iface limits/combinations, WoWLAN support, coalesce support, vendor command flags, opmode, iftype ext capa, AKM suites, and the radio config stuff. This is where you live if you write drivers, iykyk.

  • 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 lifecycle, locks & work queues

creating, registering, locking, and the entire work-queue family (regular, delayed, hrtimer) — plus wireless_dev and wdev helpers. basically the "keep it alive and thread-safe" saga 😭

🌈 Utility functions

the little helpers that carry the whole operation 🫶 channel math, freq↔channel conversion, PSC checks, radio/chandef validation, response rates, radiotap iterator, and header length helpers. These ate, no cap.

🍓 Data path helpers

the "actually move the packets" section 🚀 802.11→802.3 conversion, A-MSDU checks and deaggregation, tunnel proto, mesh header stripping, 802.1d classification, and the entire element-finding family (cfg80211_find_ie* girlies stand up). Plus RNR iteration and defragmentation. Iconic.

🌸 Regulatory enforcement infrastructure

the "what am I even allowed to transmit on" department 🛂 — hints, custom regd application, freq reg info, initiator names, pre-CAC checks, and the internal regdb WMM query. Very "rules are rules" of it.

🧚 scan/BSS notifications & MLME events

everything the driver yells at cfg80211 about 📣 scan done, sched scan results/stopped, informing BSS, merging profiles, ref/put/unlink bss, MLME rx/tx, assoc resp, michael mic failure, ibss joined, new peer candidate. it's a whole group chat of events fr fr.

🙈 RFkill integration

short but crucial — telling the world the hardware got switched off 🔌

🎀 Vendor commands

for when you need your own special little commands and events 💖 alloc reply skb, reply, get sender, event alloc (unicast too), and fire the event.

💀 Test mode

yep, still here, still iconic. reply skb, reply, event skb, event. 🧪

🔥 connection/roam/disconnect notifications + everything else

the grand finale bestie 😭 connect done/bss/result/timeout, roam info & roamed, port authorized, disconnected, remain-on-channel, TID stats alloc/release, new/del sta, rx/tx mgmt paths, control port, CQM notifications (rssi, pktloss, txe, beacon loss), radar + CAC events, GTK rekey, pmksa candidate, spurious/unexpected frames, probe status, OBSS beacon reports, and the beaconing check config. We made it. Periodt. 👑

…okay so the SEE ALSO situation is still going, and honestly? it's giving extended universe. every single one of these is a <cyan>(9)</cyan> kernel-doc page, spelled exactly like the manpage spells them, no edits, no merges — collect them all like they're limited-edition stickers: 🫶

real talk: that's the whole list, nothing skipped, nothing renamed. if a page up there is the one you actually needed, go read that one — this page is just the ✨connector✨. 💅

and that's a wrap on the whole page, bestie!! 🎀 source lives in ./include/net, it's from October 2026, and yes — it's still nl80211_send_chandef(9) in the corner, serving main-character energy right to the very last line. 🌈⭐ you read the whole thing, which lowkey makes you iconic. periodt. 💖🦋

📦 where this page comes from