batadv_dat_check_dhcp_ack(9)

📦 version 7.3.1, in nixpkgs unstable

💖 batadv_dat_check_dhcp_ack(9) 💖

okay so bestie, we're in the Kernel API Manual today and this one's a little function with a big job — think of it as the bouncer at the club door of your network stack, checking IDs for DHCP ACKs ✨

🌸 NAME 🌸

batadv_dat_check_dhcp_ack — examine a packet to see if it's a valid DHCP message, no cap 🕵️‍♀️

🦋 SYNOPSIS 🦋

bool batadv_dat_check_dhcp_ack (struct sk_buff *skb , __be16 proto ,
       __be32 *ip_src , u8 *chaddr , __be32 *yiaddr );

like, that's the whole signature, literally all of it, don't @ me 💅

🎀 ARGUMENTS 🎀

  • skb — the packet we're checking, the main character of this whole situation 📦
  • proto — the ethernet protocol hint (and yeah, it's behind a potential vlan, so heads up for that)
  • ip_src — a buffer where we're gonna stash the IPv4 source address 🏠
  • chaddr — a buffer for the DHCP Client Hardware Address (the client's MAC, iykyk)
  • yiaddr — a buffer for the DHCP Your IP Address field, yes that's the actual name, iconic

🔥 DESCRIPTION 🔥

So what it does: it checks whether the given skb is a valid DHCPACK. And if it is? It stores three things in the buffers you so kindly provided 👑

  • the IPv4 server source address → into ip_src
  • the client MAC address → into chaddr
  • the client IPv4 address → into yiaddr
⚠️ real talk, bestie: the caller needs to make sure the skb network header is set correctly. That's not this function's problem, that's yours. Don't set it wrong and then act surprised. 🙈

⭐ RETURN ⭐

Returns True if the skb is a valid DHCPACK — slay 💅

Returns False otherwise — not it, bestie 💀

🌈 SEE ALSO 🌈

Kernel file ./net/batman-adv/distributed-arp-table.c, plus a whole friend group of symbols:

and that's the whole page, bestie 🫶 this little love letter lives in ./net/batman-adv, dated October 2026, and yes the header said batadv_dat_check_dhcp_ack(9) twice because it's extra like that 💅✨ go read your network headers correctly, mwah 🎀

📦 where this page comes from