sel_netport_sid(9)

🦋 sel_netport_sid — a Kernel API Manual moment 🦋

okay so bestie, welcome to the Kernel API Manual — yes that's the actual manual name, we're in the big leagues now 💅 — and today's main character is a lil function called sel_netport_sid. she's small, she's fast, she's literally the lookup girlie for network port SIDs. let's get into it ✨

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🌸 NAME 🌸

sel_netport_sid — Lookup the SID of a network port

like, that's her whole job. finding the SID for a network port. no cap 🫶

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✨ SYNOPSIS ✨

int sel_netport_sid (u8 protocol , u16 pnum , u32 *sid );

three args, one int coming back at you. that's it, that's the whole signature, she's lowkey minimalist 🔥

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🎀 ARGUMENTS 🎀

• protocol — the protocol. that's it. that's the description. the protocol. (yes the original is literally just "protocol", she's a woman of few words 💀)
• pnum — the port. the port number in question, bestie.
• sid — the port SID. this is where the answer lands, it's a u32 * so it's giving "output parameter" main character energy 👑

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💖 DESCRIPTION 💖

okay so here's the tea ☕ — this function determines the SID of a network port using the fastest method possible. like she is not wasting your time, she is not doing extra work, she is efficient and iconic for it 💅

the way it works, step by step:

1. first, the port table gets queried — quick lil lookup, love that for us 🌈
2. but if an entry can't be found, then the policy gets queried instead
3. and then the result gets added to the table so future queries are speedup-ed 🚀 (yes, speedup. she's helping future-you. self-care fr fr)

and the returns? glad you asked:

• zero on success 🎉
• negative values on failure 😭

that's the whole vibe check. no surprises, no plot twists, just a clean lookup with a lil caching glow-up ✨

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🌟 SEE ALSO 🌟

go read these, they're the friend group 🫶

• Kernel file ./security/selinux/netport.c
• sel_netport_hashfn(9)
• sel_netport_find(9)
• sel_netport_insert(9)
• sel_netport_sid_slow(9) — yes there's a slow version, and honestly? relatable. sometimes you gotta be the slow one 😭
• sel_netport_flush(9)

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okay that's the page!! this whole thing lives in ./security/selinux and the manual itself is dated October 2026 — yes, from the future, she's ahead of her time 🧚💜 anyway bestie go read the source, mwah 💋🎀