napi_build_skb(9)

✨ napi_build_skb(9) ✨

okay so bestie, buckle up — this is a page from the Kernel API Manual, and it's about napi_build_skb. yes it's a C function in the kernel. no it's not scary. let's go 💅

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💖 NAME 💖

napi_build_skb — build a network buffer

like, literally build one. that's the whole job. 🎀

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🌸 SYNOPSIS 🌸

struct sk_buff * napi_build_skb (void *data , unsigned int frag_size );

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🦋 ARGUMENTS 🦋

• data — the data buffer, handed to you by the caller. it's giving "i brought the snacks" 🍓
• frag_size — size of data. how much snack we're working with fr fr

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✨ DESCRIPTION ✨

so this is the version of __napi_build_skb that takes care of skb->head_frag and skb->pfmemalloc when the data is a page or a page fragment. it handles the bookkeeping so you don't have to — main character energy honestly 👑

it returns a new sk_buff on success, and NULL on allocation failure. that's it. no cap. if you get NULL, the allocation just didn't work out 😭

lowkey important: success means a fresh sk_buff, failure means NULL — there is no in-between, bestie.

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🌈 SEE ALSO 🌈

Kernel file ./net/core/skbuff.c — and honestly the whole skb friend group showed up to the group chat: drop_reasons_register_subsys(9), drop_reasons_unregister_subsys(9), skb_panic(9), napi_skb_cache_get_bulk(9), __build_skb(9), build_skb_around(9), __napi_build_skb(9), __alloc_skb(9), __netdev_alloc_skb(9), napi_alloc_skb(9), skb_pp_cow_data(9), skb_pp_frag_ref(9), __kfree_skb(9), sk_skb_reason_drop(9), skb_tx_error(9), consume_skb(9), __consume_stateless_skb(9), napi_consume_skb(9), alloc_skb_for_msg(9), skb_morph(9), skb_copy_ubufs(9), skb_clone(9), skb_copy(9), __pskb_copy_fclone(9), pskb_expand_head(9), skb_expand_head(9), skb_copy_expand(9), __skb_pad(9), pskb_put(9), skb_put(9), skb_push(9), skb_pull(9), skb_pull_data(9), skb_trim(9), __pskb_pull_tail(9), skb_copy_bits(9), skb_store_bits(9), skb_zerocopy(9), skb_dequeue(9), skb_dequeue_tail(9), skb_queue_purge_reason(9), skb_rbtree_purge(9), skb_queue_head(9), skb_queue_tail(9), skb_unlink(9), skb_append(9), skb_split(9), skb_shift(9), skb_prepare_seq_read(9), skb_seq_read(9), skb_abort_seq_read(9), skb_copy_seq_read(9), skb_find_text(9), skb_pull_rcsum(9), skb_segment(9), skb_to_sgvec(9), skb_cow_data(9), skb_clone_sk(9), skb_partial_csum_set(9), skb_checksum_setup(9), skb_checksum_maybe_trim(9), skb_checksum_trimmed(9), skb_try_coalesce(9), skb_scrub_packet(9), skb_eth_pop(9), skb_eth_push(9), skb_mpls_push(9), skb_mpls_pop(9), skb_mpls_update_lse(9), skb_mpls_dec_ttl(9), alloc_skb_with_frags(9), skb_condense(9), __skb_ext_alloc(9), __skb_ext_set(9), skb_ext_add(9), skb_attempt_defer_free(9), skb_splice_from_iter(9).

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🫶 mwah, that's the page!! this one's from ./net/core, dated October 2026, and it's filed under napi_build_skb(9) — go build some skbs, bestie, you're gonna slay 💖✨