STRUCT FLOW_DISSECTOR_KEY_CFM(9)

💅 struct flow_dissector_key_cfm(9) 💅

okay so this is a page straight out of the Kernel API Manual and honestly? it's a little baby struct with main character energy. two fields. that's it. that's the whole vibe. let's get into it bestie 🫶

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✨ SYNOPSIS ✨

struct flow_dissector_key_cfm {
    u8 mdl_ver;
    u8 opcode;
 };

that's the whole thing. two u8s and a dream 💖

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🌸 Members 🌸

• mdl_ver — the maintenance domain level (mdl) and the cfm protocol version, both squished into one little byte. multitasking icon ✨
• opcode — the code that tells you which type of cfm protocol packet this is. it's giving "which one of my outfits is this" 💅

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🦋 Description 🦋

so like, for the full lore you gotta see 802.1ag and ITU-T G.8013/Y.1731, no cap. here's the bit layout they're on about:

1               2 |7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|

and here's the cute lil diagram of how it all sits together:

┌────────────────────────┐
│ mdl   version   opcode │
└────────────────────────┘

look at her. precious. the mdl and version share a spot, opcode gets its own, periodt 🎀

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👑 SEE ALSO 👑

go check out the kernel file ./include/net/flow_dissector.h, plus literally the entire extended family of these structs — the way they all reference each other is so sibling-coded 😭

• struct flow_dissector_key_control(9)
• struct flow_dissector_key_basic(9)
• struct flow_dissector_key_enc_opts(9)
• struct flow_dissector_key_ipv4_addrs(9)
• struct flow_dissector_key_ipv6_addrs(9)
• struct flow_dissector_key_tipc(9)
• struct flow_dissector_key_addrs(9)
• struct flow_dissector_key_arp(9)
• struct flow_dissector_key_ports(9)
• struct flow_dissector_key_ports_range(9)
• struct flow_dissector_key_icmp(9)
• struct flow_dissector_key_eth_addrs(9)
• struct flow_dissector_key_tcp(9)
• struct flow_dissector_key_ip(9)
• struct flow_dissector_key_meta(9)
• struct flow_dissector_key_ct(9)
• struct flow_dissector_key_hash(9)
• struct flow_dissector_key_num_of_vlans(9)
• struct flow_dissector_key_pppoe(9)
• struct flow_dissector_key_l2tpv3(9)
• struct flow_dissector_key_ipsec(9)

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bestie reminder: this page is a struct flow_dissector_key_cfm(9) situation from the Kernel API Manual, filed under ./include/net, dated October 2026. that's it, that's the sign-off, mwah 💋✨🧚‍♀️