STRUCT BPF_CRYPTO_CTX(9)

🌸 NAME 🌸

okay bestie, welcome to the struct bpf_crypto_ctx(9) page from the Kernel API Manual — it's literally the refcounted BPF crypto context structure. That's the whole assignment: a refcounted BPF crypto context structure. No cap, we love a name that tells you exactly what it is. 💖

✨ SYNOPSIS ✨

here's the struct in all its main-character glory:

       struct bpf_crypto_ctx {
           const struct bpf_crypto_type *type;
           void *tfm;
           u32 siv_len;
           struct rcu_head rcu;
           refcount_t usage;
        };

🎀 Members 🎀

• type — the pointer to bpf crypto type. That's it, that's the field. 🦋
• tfm — the pointer to instance of crypto API struct. Very demure, very crypto-api-core. ✨
• siv_len — the Size of IV and state storage for cipher. Important little number, fr fr. 🔥
• rcu — the RCU head used to free the crypto context with RCU safety. Gotta free it safely, bestie. 🫶
• usage — the object reference counter. When the refcount goes to 0, the memory is released back to the BPF allocator, which provides RCU safety. That's the lifecycle, periodt. 💅

🌈 SEE ALSO 🌈

• Kernel file ./kernel/bpf/crypto.c
• struct bpf_crypto_params(9)
• bpf_crypto_ctx_create(9)
• bpf_crypto_ctx_acquire(9)
• bpf_crypto_ctx_release(9)
• bpf_crypto_decrypt(9)
• bpf_crypto_encrypt(9)

these are the docs to pull up next, iykyk. 👑

xoxo, bestie 💖 — source/version: ./kernel/bpf; date: October 2026 ✨💅