vti6_addr_conflict(9)

🎀 NAME 🎀

Okay bestie, welcome to vti6_addr_conflict(9) from the Kernel API Manual — this function compares packet addresses to the tunnel’s own. Lowkey iconic loop-protection behavior, no cap. ✨

✨ SYNOPSIS ✨

bool vti6_addr_conflict (const struct ip6_tnl *t , const struct ipv6hdr *hdr );

💅 ARGUMENTS 💅

• t — the outgoing tunnel device, main character of this parameter list 🫶
• hdr — IPv6 header from the incoming packet, no cap 🦋

🦋 DESCRIPTION 🦋

The whole goal: avoid a trivial tunneling loop by checking that the tunnel exit-point doesn't match the source of the incoming packet. It’s giving “are you talking to yourself?” but for packets, and honestly? necessary. 💀✨

🔥 RETURN 🔥

• 1 if conflict, 0 else — periodt. 🔥

🌈 SEE ALSO 🌈

Kernel file: ./net/ipv6/ip6_vti.c. And the whole friend group:

• vti6_tnl_lookup(9)
• vti6_tnl_bucket(9)
• vti6_locate(9)
• vti6_dev_uninit(9)
• vti6_xmit(9)
• vti6_tnl_change(9)
• vti6_siocdevprivate(9)
• vti6_dev_setup(9)
• vti6_dev_init_gen(9)
• vti6_dev_init(9)
• vti6_fb_tnl_dev_init(9)
• vti6_tunnel_init(9)
• vti6_tunnel_cleanup(9)

Sign-off: source ./net/ipv6, date October 2026, page vti6_addr_conflict(9) — byeee bestie, go prevent those loops 💅🎀