xt_write_recseq_begin(9)

💅 xt_write_recseq_begin(9) 💅

okay so this one's from the Kernel API Manual and honestly? she's a little gatekeeper and she knows it. bestie, buckle up 🎀

---

✨ NAME ✨

xt_write_recseq_begin — start of a write section. literally the opening number of the whole write-section era. no cap 💖

---

🌸 SYNOPSIS 🌸

unsigned int xt_write_recseq_begin (void );

like… that's it. that's the whole vibe check on the signature. iconique 🦋

---

🧚 ARGUMENTS 🧚

• void — no arguments. zero. nada. she takes nothing from you, she simply arrives ✨ (ngl a little main character energy of her)

---

👑 DESCRIPTION 👑

Begin packet processing : all readers must wait the end 👀

like fr fr, the moment you call this, the packet-processing section has officially begun, and every single reader out there has to wait for the end. no sneaking a peek early, we don't do that here 💅

there are two things you gotta have sorted before you even think about calling her, and they're numbered, so you know it's serious:

1. Must be called with preemption disabled — yes, disabled, like actually off. do not skip this, i'm begging 😭
2. softirqs must be disabled too (or we should use this_cpu_add) — so either they're already off, or you go the this_cpu_add route. pick one, bestie 🫶

⚠️ okay this is the part where i hold your hand: these two preconditions are not suggestions, they're requirements. get them wrong and things get real cursed real fast 💀

---

⭐ RETURN ⭐

here's the tea, and she's a tiny bit cryptic on purpose:

• 1 — if no recursion on this cpu 🌈 (slay, we're clean)
• 0 — if recursion detected 🙈 (not slay, go fix that)

so like… check the return value, please. i'm asking nicely 💜

---

🍓 SEE ALSO 🍓

okay these are all the linked besties, and there are a lot of them, so let's go:

• Kernel file ./include/linux/netfilter/x_tables.h — the source file, the origin story, the blueprint 📜
• struct xt_action_param(9)
• struct xt_mtchk_param(9)
• struct xt_mtdtor_param(9)
• struct xt_tgchk_param(9)
• var xt_recseq(9)
• xt_write_recseq_end(9) — okay she's the end, the natural sequel, the closing number 🔥

---

and that's the whole page, bestie 🧵✨ sending you off with the most important lore of all: this one lives in ./include/linux/netfilter, the manual version is dated October 2026 (yes, future queen behavior 🌸), and the whole thing is filed under xt_write_recseq_begin(9) in the Kernel API Manual — periodt, go read xt_write_recseq_end(9) next, love u, bye 🎀💖🦋