ieee80211_amsdu_to_8023s(9)

📦 version 7.3.1, in nixpkgs unstable

💫 ieee80211_amsdu_to_8023s(9) — the Kernel API Manual, bestie edition 💫

okay so picture this: you're deep in the kernel, section 9 of the manual, and you've got yourself an A-MSDU frame that needs decoding. this is literally the page for that. welcome, i'm so glad you're here 🫶

✨ NAME ✨

ieee80211_amsdu_to_8023s — decode an IEEE 802.11n A-MSDU frame 💅

🌸 SYNOPSIS 🌸

void ieee80211_amsdu_to_8023s (struct sk_buff *skb , struct sk_buff_head
*list , const u8 *addr , enum nl80211_iftype iftype , const unsigned int
extra_headroom , const u8 *check_da , const u8 *check_sa , u8
mesh_control );

like, yes, that's a whole lot of parameters. we'll get through them together, one at a time, no cap 🎀

🦋 ARGUMENTS 🦋

  • skb — the input A-MSDU frame, and bestie listen: it comes in with no headers at all. fully header-less. naked frame energy 🫣
  • list — the output list of 802.3 frames. heads up tho: you (the caller) have to allocate and initialize it. it is not gonna do that for you, it's not that kind of function 💀
  • addr — the device MAC address ✨
  • iftype — the device interface type, as an enum nl80211_iftype 💜
  • extra_headroom — the hardware extra headroom for SKBs in the list. an const unsigned int, iconic, mysterious, necessary 🌈
  • check_da — the DA to check in the inner ethernet header, or NULL. your choice, main character 🎀
  • check_sa — the SA to check in the inner ethernet header, or NULL. same vibe, different destination/source situation, iykyk 🌸
  • mesh_control — see mesh_hdr in ieee80211_is_valid_amsdu. that's the whole description. go look at that one for the lore 🧚

🔥 DESCRIPTION 🔥

so what does this actually do? it decodes an IEEE 802.11 A-MSDU and converts it into a list of 802.3 frames. one in, a whole little list out — it's giving assembly line, it's giving transformation arc 👑

⚠️ real talk: the list will be empty if the decode fails. no partial results, no leftovers, just vibes and an empty list. 😭
💀 and the important one: the skb must be fully header-less before being passed in here — and it is freed in this function. so do not, i repeat, do not go touching that skb afterwards. it's gone. periodt.

more parts coming, don't go anywhere bestie 💖

💅 SEE ALSO 💅

okay bestie, buckle up, because this is the part where the manpage introduces you to its entire friend group 😭 and it is a LOT of friends. like, "my birthday party is at a stadium" levels of friends. every single one of these is a (9) page, every single one is real, and we're listing them all because we do not gatekeep here 💖

first up, the literal source file that started all of this, plus the foundational lore:

look at all those caps. HT, VHT, HE, EHT, UHR — it's giving alphabet soup but make it ✨wireless✨. EHT and UHR are the newer kids and honestly they ate 🔥

🎀 Actions and configuration 🎀

the chandef squad is lowkey the main character here — channel definition girlies stay winning 👑 and dfs is everywhere because radar avoidance is not a vibe you skip, bestie, that one's legally required 💀

  • 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)

mesh? ocb? sar? we contain multitudes fr fr 🦋

🌸 Scanning and BSS list handling 🌸

  • 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)

wowlan bestie!! wake-on-wireless-lan!! the laptop stays asleep but still listens, that's iconic behavior honestly 😴✨

the wiphy_work / wiphy_delayed_work / wiphy_hrtimer_work trio is giving "three siblings, same energy, different timers" 💀 queue, cancel, flush, pending — the whole choreography, periodt.

🧚 Utility functions 🧚

channel number ⇄ frequency ⇄ kHz, back and forth forever, like a situationship that never ends 🔁

🫶 Data path helpers 🫶

hiiiii these are our direct coworkers 🫶 the find_ie family is basically "where's the information element" — the unsung heroes of every single frame you've ever received, no cap. and yes, ieee80211_is_valid_amsdu(9) is literally our page's bestie, go say hi 💜

🔥 Regulatory enforcement infrastructure 🔥

rules are rules bestie, and the regulatory db has OPINIONS about which frequencies you're allowed to touch 🌍 the _sync one is the one that waits — the "I'm not leaving until you answer" variant 🙈

🍓 Internal regulatory db functions 🍓

just the one internal function, sitting there, minding its business, holding the WMM rules for the regulatory database. small but mighty ⭐

ref_bss and put_bss are the classic refcount couple — you take one, you give one back, or the kernel leaks and we don't do leaks in this house 😤 also cfg80211_michael_mic_failure(9) is genuinely the coolest-sounding function name in this entire list, i said what i said 💅

🌈 RFkill integration 🌈

the airplane-mode squad ✈️ hw state + reason, and yes there's a reason parameter because "why is my wifi off" deserves an actual answer, bestie 😭

💀 Vendor commands 💀

alloc a reply, fill it, send it, don't forget to free it — the eternal cycle 🎀 and _ucast is the unicast version, for when you want to whisper to one listener instead of yelling to the whole group chat 📢

🎀 Test mode 🎀

same pattern, different subsystem — alloc / reply, alloc / event. consistency is so attractive honestly ✨

the cqm notify squad — RSSI, packet loss, TXE, beacon loss — is literally the "are you okay? are you okay? are you okay annie" of wireless 💀 connection quality monitoring stays booked and busy.

and that's the list bestie!! every single one, no skips, no cap 🌈 if you made it to the bottom, you're officially a cfg80211 scholar, go drink some water 🍓💖

...and the guest list keeps going, bestie, because this section is long and every single one of these pulled up to the function. No plus-ones were cut. 💅

okay that's genuinely everyone, i checked twice 💀

so yeah — ieee80211_amsdu_to_8023s(9) lives under ./include/net, this is the October 2026 edition, and that's the whole page! go convert some A-MSDU frames into 802.3 and slay, bestie 🫶✨

📦 where this page comes from