cnstr_shdsc_rfc4106_decap(9)

📦 version 7.3.1, in nixpkgs unstable

✨ cnstr_shdsc_rfc4106_decap ✨

okay so this is a page from the Kernel API Manual, section 9, and it's all about one very specific little function 💅

🌸 NAME 🌸

cnstr_shdsc_rfc4106_decap — the IPSec ESP gcm decapsulation shared descriptor (and yes bestie, it's the non-protocol one 🫶)

✨ SYNOPSIS ✨

void cnstr_shdsc_rfc4106_decap (u32 * const desc , struct alginfo *cdata
, unsigned int ivsize , unsigned int icvsize , const bool is_qi );

literally that's it, that's the whole signature 🎀 it returns void, so no return value to obsess over 😌

💖 ARGUMENTS 💖

  • desc — pointer to the buffer used for descriptor construction 🧚 this is where the magic gets written, no cap
  • cdata — pointer to block cipher transform definitions 🦋 and here's the vibe check on the values: valid algorithm values are OP_ALG_ALGSEL_AES ANDed with OP_ALG_AAI_GCM. like, that's the combo, periodt 🔥
  • ivsize — initialization vector size ⭐
  • icvsize — integrity check value (ICV) size, and it can be truncated or full 💅 your call
  • is_qi — a bool, and it's true when called from caam/qi 🌈

👑 SEE ALSO 👑

the kernel file it lives in, first of all: ./drivers/crypto/caam/caamalg_desc.c 💜

and the whole friend group of related functions, all in section 9:

like ok go off, the entire caam crypto squad showed up 😭💀

and that's the whole page bestie, mwah 💋 this one came straight out of ./drivers/crypto/caam and it's dated October 2026, so yeah — go build those descriptors, you're gonna slay 🎀✨🦋

📦 where this page comes from