__nla_reserve_64bit(9)

📦 version 7.3.1, in nixpkgs unstable

✨ __nla_reserve_64bit(9) ✨

okay so this is a page from the Kernel API Manual, and honestly? it's a little baddie. it does one job and it does it immaculately. let's get into it 💅

🌸 NAME 🌸

__nla_reserve_64bit — reserve room for an attribute on the skb, and align it. that's it, that's the whole vibe 🎀

🦋 SYNOPSIS 🦋

struct nlattr * __nla_reserve_64bit (struct sk_buff *skb , int attrtype
, int attrlen , int padattr );

look at her. four args, no notes. ✨

💜 ARGUMENTS 💜

  • skb — the socket buffer where we're reserving room, bestie. that's the canvas 🎨
  • attrtype — the attribute type. it's giving "who am i" energy 👑
  • attrlen — the length of the attribute payload, aka how much room the actual content needs 📏
  • padattr — the attribute type used for the padding 🎀

🔥 DESCRIPTION 🔥

so what does she do? she adds a netlink attribute header to a socket buffer, and she reserves room for the payload — but she does not copy it. nope! not her job, not her problem 🙈 the payload copying is somebody else's main character arc.

she also makes sure this attribute will have a 64-bit aligned nla_data area. alignment slay. not me being obsessed with memory layout 💅

⚠️ heads up: the caller is responsible for making sure the skb actually provides enough tailroom for the attribute header and the payload. that's on you, babe. she trusts you. don't fumble it 😭

⭐ SEE ALSO ⭐

go read the whole friend group — they all live in the kernel file ./lib/nlattr.c:

🫶 and that's the whole page!! she's from the ./lib directory, dated October 2026, and her name is __nla_reserve_64bit(9). periodt. go reserve some room responsibly 💖✨🌈

📦 where this page comes from