STRUCT LIBETH_RX_CSUM(9)

✨ struct libeth_rx_csum(9) ✨

okay so bestie, this page lives in the Kernel API Manual and it's literally all about one lil struct — struct libeth_rx_csum — which holds the checksum offload bits that got decoded straight out of the Rx descriptor. that's it, that's the vibe 💅

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💖 NAME 💖

struct libeth_rx_csum — the checksum offload bits, decoded from the Rx descriptor 🎀

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🦋 SYNOPSIS 🦋

struct libeth_rx_csum {
    u32 l3l4p:1;
    u32 ipe:1;
    u32 eipe:1;
    u32 eudpe:1;
    u32 ipv6exadd:1;
    u32 l4e:1;
    u32 pprs:1;
    u32 nat:1;
    u32 raw_csum_valid:1;
    u32 pad:7;
    u32 raw_csum:16;
 };

look at her, all bitfields and perfectly packed 😌 no cap, every field is u32, and the bit widths are exactly as written above — do not touch, do not "clean up". fr fr.

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🌸 Members 🌸

okay here's the cast of characters, one bitfield at a time 👑

• l3l4p — the detectable L3 and L4 integrity check is processed by the hardware 🔥
• ipe — IP checksum error 💀
• eipe — external (outermost) IP header — only for tunnels
• eudpe — external (outermost) UDP checksum error — only for tunnels
• ipv6exadd — IPv6 header with extension headers ✨
• l4e — L4 integrity error 😭
• pprs — set for packets that skip checksum calculation in the HW pre parser 🧚
• nat — the packet is a UDP tunneled packet 🌀
• raw_csum_valid — set if the raw checksum is valid ✅
• pad — padding, there purely to naturally align the raw_csum field 🎀
• raw_csum — the raw checksum itself 🍓

small heads-up bestie: eipe and eudpe are the external, i.e. outermost, header ones — and they only apply to tunnels. don't go reading them for normal packets, that's not the move 🙈

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🌈 SEE ALSO 🌈

go read these next, i'm obsessed with this little cluster of files honestly 🫶

• Kernel file ./include/net/libeth/rx.h
• struct libeth_fqe(9)
• enum libeth_fqe_type(9)
• struct libeth_fq(9)
• libeth_rx_alloc(9)
• libeth_rx_sync_for_cpu(9)
• struct libeth_rqe_info(9)
• libeth_rx_pt_get_ip_ver(9)
• libeth_rx_pt_set_hash(9)

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ok that's the whole page, periodt 💜 huge shoutout to the ./include/net/libeth directory for being the source of truth, and to the October 2026 release for dating this little masterpiece. go read the header file, ily, bye 🎀✨