eth_header_cache_update(9)

💅 eth_header_cache_update(9)

ok so this is a page straight outta the Kernel API Manual — yes, that Kernel API Manual — and it's about one (1) tiny little function that keeps your network cache from lying to you. let's go ✨

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🌸 NAME 🌸

eth_header_cache_update — update cache entry 🎀

like, the function's whole job is updating the cache entry. that's it. that's the tweet.

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🦋 SYNOPSIS 🦋

void eth_header_cache_update (struct hh_cache *hh , const struct
       net_device *dev , const unsigned char *haddr );

three args, returns void, no drama. she takes her params and she leaves. 💅

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✨ ARGUMENTS ✨

• hh — the destination cache entry, aka the thing getting updated. she's the destination, bestie 💖
• dev — the network device. the hardware baddie in question 🫶
• haddr — the new hardware address. fresh off the press, brand new, no cap ⭐

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🔥 DESCRIPTION 🔥

ok so here's the vibe — this one gets called by the Address Resolution module to notify changes in address. that's literally it, that's the whole description, and honestly? iconic. minimal. main character energy.

so when an address changes, AR is like "hey bestie, heads up" and eth_header_cache_update is the one making sure the cache entry actually knows about it. no stale vibes allowed in this house 🚫💀

lowkey important: if you're poking around here, remember this is called by the Address Resolution module — it's a notification path, not something you just summon for fun 🙈

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👑 SEE ALSO 👑

this is the friend group, fr fr — the whole squad lives over in the kernel file ./net/ethernet/eth.c:

• eth_header(9)
• eth_get_headlen(9)
• eth_type_trans(9)
• eth_header_cache(9)
• eth_header_parse_protocol(9)
• eth_prepare_mac_addr_change(9)
• eth_commit_mac_addr_change(9)
• eth_mac_addr(9)
• ether_setup(9)
• alloc_etherdev_mqs(9)
• platform_get_ethdev_address(9)
• nvmem_get_mac_address(9)
• fwnode_get_mac_address(9)
• device_get_mac_address(9)
• device_get_ethdev_address(9)

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aaaand that's the page, bestie 🌈 this lil gem comes to you from ./net/ethernet and it's stamped October 2026 — go forth and keep those caches fresh 💜🎀🌸