STRUCT NFT_BASE_CHAIN(9)

💅 struct nft_base_chain(9) — the nf_tables base chain, bestie

okay so real talk, this is a page from the Kernel API Manual and it's all about struct nft_base_chain, which is literally the nf_tables base chain. it's giving kernel-internals main character energy and honestly? we're obsessed. let's get into it 🫶

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✨ NAME ✨

struct nft_base_chain — the nf_tables base chain. that's it, that's the vibe. 💖

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🌸 SYNOPSIS 🌸

here's the whole struct, copied exactly because we do not mess with kernel source in this house:

struct nft_base_chain {
    struct nf_hook_ops              ops;
    struct list_head                hook_list;
    const struct nft_chain_type     *type;
    u8 policy;
    u8 flags;
    struct nft_stats __percpu       *stats;
    struct nft_chain                chain;
    struct flow_block               flow_block;
 };

look at her. eight members. iconic. ✨

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🎀 Members 🎀

okay so let's meet the cast, one by one:

• ops — netfilter hook ops. yes bestie, the actual hook operations 💅
• hook_list — a list of netfilter hooks (for the NFPROTO_NETDEV family — iykyk) 🔥
• type — the chain type. literally what kind of chain she is 🌈
• policy — the default policy. the default!! the blueprint!! 👑
• flags — these indicate whether the base chain is disabled or not. vibe check, basically 💀
• stats — per-cpu chain stats. per. cpu. she's tracking everything fr fr 🍓
• chain — the chain. yes the chain inside the base chain, it's chains all the way down 🧚
• flow_block — flow block (for hardware offload). offloading to the hardware, slay ⭐

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🦋 SEE ALSO 🦋

bestie, this section is LONG and we are NOT skipping a single one of these, so buckle up. all of these live in the kernel file ./include/net/netfilter/nf_tables.h:

• struct nft_verdict(9)
• struct nft_regs(9)
• struct nft_ctx(9)
• struct nft_userdata(9)
• struct nft_set_elem(9)
• enum nft_iter_type(9)
• struct nft_set_desc(9)
• enum nft_set_class(9)
• struct nft_set_estimate(9)
• struct nft_expr(9)
• struct nft_set_ops(9)
• struct nft_set_type(9)
• struct nft_set(9)
• struct nft_set_binding(9)
• enum nft_set_extensions(9)
• struct nft_set_ext_type(9)
• struct nft_set_ext_tmpl(9)
• struct nft_set_ext(9)
• struct nft_expr_type(9)
• struct nft_expr_ops(9)
• struct nft_rule(9)
• struct nft_chain_validate_state(9)
• struct nft_chain(9)
• struct nft_chain_type(9)
• struct nft_table(9)
• struct nft_object_hash_key(9)
• struct nft_object(9)
• struct nft_object_type(9)
• struct nft_object_ops(9)
• struct nft_flowtable(9)
• struct nft_traceinfo(9)
• struct nft_trans(9)
• struct nft_trans_hook(9)
• struct nft_trans_binding(9)

like I said. a whole friend group. go read all of them, no cap 😭

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ngl this page is just the struct and its members — no options, no exit statuses, no bugs section. so if you made it this far you've literally absorbed 100% of the content. ate and left no crumbs 💅

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and that's the page!! this one ships from ./include/net/netfilter, dated October 2026, and yeah — the manual name on the tin is struct nft_base_chain(9). mwah 💖✨🎀