skb_postpush_rcsum(9)

📦 version 7.3.1, in nixpkgs unstable

✨ skb_postpush_rcsum ✨

okay so bestie, this is a page from the Kernel API Manual — yes, that manual. We're doing kernel networking today, and honestly? It's giving main character energy. 🎀

🌸 NAME 🌸

skb_postpush_rcsum — update checksum for received skb after push

like. that's the whole vibe. you pushed data, now fix the checksum. 💅

🦋 SYNOPSIS 🦋

void skb_postpush_rcsum (struct sk_buff *skb , const void *start ,
unsigned int len );

no cap, that's the entire signature. short, sweet, slays. ✨

💖 ARGUMENTS 💖

  • skb — the buffer to update 🫶 (the skb you're out here touching)
  • start — start of data after push 📍 (where the new data begins now that you've moved things)
  • len — length of data pushed 📏 (how much you pushed, be honest)

🔥 DESCRIPTION 🔥

So here's the situation, bestie: after doing a push on a received packet, you need to call this function to update the CHECKSUM_COMPLETE checksum. That's it. That's the whole job. 🌈

Not me explaining it in one sentence — it literally is one sentence of lore, and that sentence is important. If you push and don't call this, your CHECKSUM_COMPLETE is stuck living a lie. 😭

fr fr: this only applies to received packets, and only to the CHECKSUM_COMPLETE checksum. read the room before calling it.

👑 SEE ALSO 👑

Buckle up, this list is long and it ate. 💀

Kernel file ./include/linux/skbuff.h

no because why is this list lowkey a whole friend group 💜 — anyway, all of these are legit, go read them, iykyk.

and that's the whole page, bestie. this one came out of ./include/linux in October 2026 — like, future-dated icon behavior ⭐ go forth and keep those checksums honest 🧚💖

📦 where this page comes from