xdr_restrict_buflen(9)

📦 version 7.3.1, in nixpkgs unstable

✨ xdr_restrict_buflen 💅

ok so this is a page from the Kernel API Manual bestie — section 9, kernel land, we're deep in it 🫶

🌸 NAME 🌸

xdr_restrict_buflen — decrease available buffer space ✨ like literally just shrink the vibe of how much room you've got left

🎀 SYNOPSIS 🎀

int xdr_restrict_buflen (struct xdr_stream *xdr , int newbuflen );

🦋 ARGUMENTS 🦋

  • xdr — pointer to xdr_stream 👑 (yes the main character struct, we love her)
  • newbuflen — the new maximum number of bytes available, a.k.a. your new budget bestie 💸

💖 DESCRIPTION 💖

Okay so what this does is it adjusts our idea of how much space is available in the buffer. That's it. That's the whole thing. A little vibe check on the buffer's capacity ✨

But it's giving conditional, so listen up:

  • If we've already used too much space in the buffer — it returns -1. Yeah. It's over, no cap 😭
  • If the available space is already smaller than newbuflen, it returns 0 and does nothing. Like it literally does not touch anything, it just says "been there, smaller already" 🙈
  • Otherwise (the actual slay case), it adjusts xdr->buf->buflen to newbuflen and makes sure xdr->end is set at most offset newbuflen from the start of the buffer. Iconic. Periodt. 💅
ngl the -1 return is the "you already messed up" signal and the 0 return is the "no changes needed, we're chill" signal — keep those straight bestie 🧠

🔥 SEE ALSO 🔥

Kernel file ./net/sunrpc/xdr.c — and honestly the entire xdr cinematic universe, here's the whole friend group 🫶:

ok that's the whole page 💜 this beautiful thing lives in ./net/sunrpc and the manual's dated October 2026 — go forth and shrink those buffers responsibly bestie, mwah 🍓🧚✨

📦 where this page comes from