smk_ipv4_check(9)

📦 version 7.3.1, in nixpkgs unstable

💅 NAME 💅

hey bestie, welcome to smk_ipv4_check(9) — that's section 9 of the Kernel API Manual, iykyk 🫶 — and it's literally all about Perform IPv4 host access checks. that's the whole vibe of this page, no cap.

✨ SYNOPSIS ✨

int smk_ipv4_check (struct sock *sk , struct sockaddr_in *sap );

that's it. that's the whole call. two args, one int coming back at you 🎀

🎯 ARGUMENTS 🎯

  • sk — the socket. like, the actual socket bestie, the thing doing the networking 💖
  • sap — the destination address. where the packet is trying to go 🦋

🌸 DESCRIPTION 🌸

okay so here's the tea ☕: this function sets the correct secattr for the given socket based on the destination address, and then it does any outbound access checks needed. so like, it looks at where you're headed, labels the socket right, and then checks if you're even allowed to go there. main character energy tbh 👑

and what does it give back? it returns 0 on success or an error code. that's it. 0 means slay, anything else means the access check said excuse me no 💀

ngl this is one of those quiet little functions that's doing security work behind the scenes, so treat those return values with respect fr fr 🙈

🌈 SEE ALSO 🌈

you want the whole friend group? because you're getting the WHOLE friend group. every single one of these lives in the kernel file ./security/smack/smack_lsm.c, and yes I'm listing every last one, no skipping, periodt 💅✨

like I said. the whole group chat 🫶

and that's the page bestie!! source is ./security/smack, dated October 2026, and honestly? iconic. go check your IPv4 access, ily, bye 💜🧚🍓

📦 where this page comes from