ieee80211_i...short_beacon(9)

✨ ieee80211_i...short_beacon(9) ✨

okay so bestie, this is a page from the Kernel API Manual — yes, the actual kernel, not a vibe. it's all about one tiny function called ieee80211_is_s1g_short_beacon, and honestly? it's giving "small function, big lore." let's get into it 🎀

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🌸 NAME 🌸

ieee80211_is_s1g_short_beacon — check if frame is an S1G short beacon 💅

like, that's the whole job. she checks. she reports. she slays.

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🦋 SYNOPSIS 🦋

bool ieee80211_is_s1g_short_beacon (__le16 fc , const u8 *variable ,
       size_t variable_len );

that's the whole signature, no cap. it hands you back a bool — true or false, iconic behavior.

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💖 ARGUMENTS 💖

• fc — frame control bytes in little-endian byteorder. little-endian fr fr, don't come at her with big-endian energy 🙈
• variable — pointer to the beacon frame elements. just a pointer, she's not copying anything, she's just looking 👀
• variable_len — length of the frame elements. gotta know how much to look at, periodt.

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👑 RETURN 👑

returns whether or not the frame is an S1G short beacon. so basically a yes/no vibe check 🌈

and here's the reasoning, which is genuinely kind of beautiful ngl. As per IEEE80211-2024 11.1.3.10.1, The S1G beacon compatibility element shall always be present as the first element in beacon frames generated at a TBTT (Target Beacon Transmission Time), so any frame not containing this element must have been generated at a TSBTT (Target Short Beacon Transmission Time) that is not a TBTT.

Additionally, short beacons are prohibited from containing the S1G beacon compatibility element as per IEEE80211-2024 9.3.4.3 Table 9-76, so if we have an S1G beacon with either no elements or the first element is not the beacon compatibility element, we have a short beacon.

🧚 so the logic is literally: no compat element as element #1? congrats bestie, it's a short beacon. the spec said so, not me.

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⭐ SEE ALSO ⭐

• Kernel file ./include/linux/ieee80211-s1g.h — the home base, the main character location 🏠
• ieee80211_is_s1g_beacon(9)
• ieee80211_s1g_has_next_tbtt(9)
• ieee80211_s1g_has_ano(9)
• ieee80211_s1g_has_cssid(9)
• enum ieee80211_s1g_chanwidth(9)
• enum ieee80211_s1g_pri_chanwidth(9)
• struct ieee80211_s1g_bcn_compat_ie(9)
• struct ieee80211_s1g_oper_ie(9)
• struct ieee80211_aid_response_ie(9)
• ieee80211_s1g_optional_len(9)

all of these are her friends, her group chat, her support system 🫶 go read them too, iykyk.

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and that's the page!! this little cutie lives in ./include/linux, dated October 2026, and the header at the top of this whole thing was ieee80211_i...short_beacon(9) all along — we been knew 💜 byeeeee 👋✨