STRUCT DPKG_EXTRACT(9)

🎀 struct dpkg_extract(9) 🎀

okay so bestie, welcome to the Kernel API Manual — this is the page for struct dpkg_extract, and it's literally just a structure for defining a single extraction. one extraction. that's the whole vibe. let's get into it 💅

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✨ NAME ✨

struct dpkg_extract — a structure for defining a single extraction 🫶

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🌸 SYNOPSIS 🌸

struct dpkg_extract {
    enum dpkg_extract_type type;
    union {
      struct {
        enum net_prot                   prot;
        enum dpkg_extract_from_hdr_type type;
        u32 field;
        u8 size;
        u8 offset;
        u8 hdr_index;
      } from_hdr;
      struct {
        u8 size;
        u8 offset;
      } from_data;
      struct {
        u8 size;
        u8 offset;
      } from_parse;
    } extract;
    u8 num_of_byte_masks;
    struct dpkg_mask        masks[DPKG_NUM_OF_MASKS];
 };

like, look at her. nested structs in a union in a struct. main character energy fr fr 👑

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🦋 Members 🦋

okay so here's the cast of characters, no cap:

• type — this one decides how the union down below gets read. it's giving "choose your fighter":
  • DPKG_EXTRACT_FROM_HDR: selects from_hdr 💖
  • DPKG_EXTRACT_FROM_DATA: selects from_data 💖
  • DPKG_EXTRACT_FROM_PARSE: selects from_parse 💖
• extract — selects the extraction method, iconic behavior
• extract.from_hdr — used when type = DPKG_EXTRACT_FROM_HDR
• extract.from_hdr.prot — any of the supported headers
• extract.from_hdr.type — defines the type of header extraction, and it's a whole little menu:
  • DPKG_FROM_HDR: use size & offset below
  • DPKG_FROM_FIELD: use field, size and offset below
  • DPKG_FULL_FIELD: use field below
• extract.from_hdr.field — one of the supported fields (NH_FLD_)
• extract.from_hdr.size — size in bytes
• extract.from_hdr.offset — byte offset
• extract.from_hdr.hdr_index — clear for cases not listed below; used for protocols that may have more than a single header, 0 indicates an outer header. supported protocols (possible values): NET_PROT_VLAN (0, HDR_INDEX_LAST); NET_PROT_MPLS (0, 1, HDR_INDEX_LAST); NET_PROT_IP(0, HDR_INDEX_LAST); NET_PROT_IPv4(0, HDR_INDEX_LAST); NET_PROT_IPv6(0, HDR_INDEX_LAST); — ngl this one is doing the most but we respect her 🙈
• extract.from_data — used when type = DPKG_EXTRACT_FROM_DATA
• extract.from_data.size — size in bytes
• extract.from_data.offset — byte offset
• extract.from_parse — used when type = DPKG_EXTRACT_FROM_PARSE
• extract.from_parse.size — size in bytes
• extract.from_parse.offset — byte offset
• num_of_byte_masks — defines the number of valid entries in the array below; this is also the number of bytes to be used as masks ✨
• masks — masks parameters

lowkey reminder bestie: from_hdr, from_data and from_parse all live in the same union — only one of them is the moment at a time, and type is what tells you which one 💀

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🌈 SEE ALSO 🌈

the whole squad, go say hi:

• Kernel file ./drivers/net/ethernet/freescale/dpaa2/dpkg.h
• DPKG_NUM_OF_MASKS(9), DPKG_MAX_NUM_OF_EXTRACTS(9), enum dpkg_extract_from_hdr_type(9), enum dpkg_extract_type(9), struct dpkg_mask(9), struct dpkg_profile_cfg(9)

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and that's the page, bestie! 🍓 this lil gem lives in the kernel docs under ./drivers/net/ethernet/freesca... (yes the source line is literally truncated like that, we stan a mysterious queen) and it's dated October 2026. slay, go extract some packets 💜🧚⭐