eth_header(9)

✨ eth_header(9) ✨

okay so bestie, welcome to the Kernel API Manual 💖 this one's a lil function called eth_header, and it's literally the glow-up artist for Ethernet headers. let's get into it 🎀

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🌸 NAME 🌸

eth_header — create the Ethernet header ✨ (yes that's the whole vibe, it makes the header)

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🦋 SYNOPSIS 🦋

int eth_header (struct sk_buff *skb , struct net_device *dev , unsigned
short type , const void *daddr , const void *saddr , unsigned int len );

like, six whole arguments, she's high maintenance but she delivers 💅

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💜 ARGUMENTS 💜

• skb — the buffer you're about to alter, bestie. this is the thing getting the makeover 🫶
• dev — the source device. where it's coming from, iykyk
• type — the Ethernet type field. the whole personality of the packet tbh
• daddr — destination address. pass NULL and you're leaving the destination address alone 🙈
• saddr — source address. pass NULL and it just uses the device source address, no drama ✨
• len — packet length. gotta be <= skb->len, so keep it in range or it's giving chaos 😭

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🔥 DESCRIPTION 🔥

so what she does: sets the protocol type. that's the main character move 👑

but here's the lil twist — for a packet of type ETH_P_802_3/2, you put the length in here instead. not the type. the length. the way that just flips the whole script, ngl 💀

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🌈 SEE ALSO 🌈

• Kernel file ./net/ethernet/eth.c
• eth_get_headlen(9)
• eth_type_trans(9)
• eth_header_cache(9)
• eth_header_cache_update(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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aaand that's the whole page, bestie 🧚💖 she lives in ./net/ethernet, dated October 2026, and the source/version is the Kernel API Manual — go forth and build headers, periodt 💅👑⭐