ip6_tnl_addr_conflict(9)

📦 version 7.3.1, in nixpkgs unstable

💖 ip6_tnl_addr_conflict — kernel API manual, but make it make sense 💖

okay so bestie, welcome to the ip6_tnl_addr_conflict(9) page — yes it's a section 9 kernel API joint, no it's not scary, I promise 🫶 it lives in the Kernel API Manual and it's literally just one little function doing one little vibe check. let's get into it ✨

🌸 NAME 🌸

ip6_tnl_addr_conflict — compare packet addresses to tunnel's own 🎀

like, literally that. it takes a look at the addresses and goes "hmm, are these the same?" no cap.

✨ SYNOPSIS ✨

bool ip6_tnl_addr_conflict (const struct ip6_tnl *t , const struct
       ipv6hdr *hdr );

she returns a bool, she takes two pointers, she's iconic, she's lowkey minimal 💅

🦋 ARGUMENTS 🦋

  • t — the outgoing tunnel device. this is your tunnel, the main character 👑
  • hdr — IPv6 header from the incoming packet. the one sliding into your mentions 📨

💜 DESCRIPTION 💜

so the whole point here? avoid trivial tunneling loop by checking that tunnel exit-point doesn't match source of incoming packet.

that's it, that's the gig. if the packet's coming from the exact same place your tunnel exits, that's a loop waiting to happen and honestly? we're not doing that 🙈 the function does the checking so you don't have to, fr fr.

⭐ RETURN ⭐

  • 1 if conflict 😭 (the addresses clash, not the vibe)
  • 0 else 🎀 (we're so back)

🌈 SEE ALSO 🌈

Kernel file ./net/ipv6/ip6_tunnel.c — the whole friend group lives here, and these are the members of the squad:

go read them all, i'll wait 💅✨

ngl bestie, section 9 pages are where the real lore lives. this one's short but she ate 🍓

and that's the page!! sourced from ./net/ipv6, dated October 2026, filed under ip6_tnl_addr_conflict(9) — mwah, catch you in the next manpage, love u bye 🧚💖

📦 where this page comes from