batadv_tt_global_crc(9)

📦 version 7.3.1, in nixpkgs unstable

💅 batadv_tt_global_crc — the Kernel API Manual tea 🫖

okay so bestie, picture this: you're deep in the kernel, the file is batadv_tt_global_crc(9), and this little icon is literally out here calculating checksums like it's nothing. let me tell you everything, no cap 💖

✨ NAME ✨

batadv_tt_global_crc — she calculates the checksum of the local table belonging to the given orig_node. that's her whole job. main character energy fr 👑

🌸 SYNOPSIS 🌸

u32 batadv_tt_global_crc (struct batadv_priv *bat_priv , struct
batadv_orig_node *orig_node , unsigned short vid );

like, she takes three things and gives you back a u32. slay ✨

🎀 ARGUMENTS 🎀

  • bat_priv — the bat priv with all the mesh interface information. she's carrying the whole mesh's info, ngl she's booked and busy 💅
  • orig_node — originator for which the CRC should be computed. yes bestie, this one, specifically 🦋
  • vid — VLAN identifier for which the CRC32 has to be computed. don't forget her, she matters 🌸

💜 DESCRIPTION 💜

okay so here's the vibe. this function computes the checksum for the global table corresponding to a specific originator. and the way she does it is honestly iconic:

for each client connected to the originator, the CRC32C of the MAC address and the VID is computed — both of them, together, no exceptions — and then all the CRC32Cs of the various clients are xor'ed together. that's the whole recipe. xor girl summer 💀✨

and the idea behind it?? honestly kind of genius. CRC32C should be used as much as possible in order to produce a unique hash of the table. but here's the plot twist: the order which is used to feed the CRC32C function affects the result, and every node in the network probably sorts the clients differently. so you literally cannot compute the hash function directly over the entire table. it's giving chaos 😭

hence — and this is the cute part — the CRC32C is used only on the single client entry, while all the results are then xor'ed together, because the XOR operation can combine them all while trying to reduce the noise as much as possible. she's doing noise reduction, she's doing math, she's doing both. obsessed 🫶

⭐ RETURN ⭐

the checksum of the global table of a given originator. that's it, that's the reward, and it's beautiful 🌈

🦋 SEE ALSO 🦋

the kernel file in question is ./net/batman-adv/translation-table.c — home base, the mothership 🏠 and here's the whole squad, every single one, i'm not skipping a single name bestie:

that's the whole roll call. every single one. periodt 🎀

ngl bestie, this page is from ./net/batman-adv, dated October 2026, and it's filed under batadv_tt_global_crc(9) in the Kernel API Manual. consider yourself fully briefed 💖✨🦋 go forth and checksum 🌈
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