iptunnel_pmtud_build_icmpv6(9)

💅 iptunnel_pmtud_build_icmpv6 — bestie edition 🎀

okay so this is a page from the Kernel API Manual, section 9, and it's all about iptunnel_pmtud_build_icmpv6. she's a lil kernel function and honestly she has one job: building an ICMPv6 error message for PMTUD. that's it. that's the whole vibe. ✨

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🌸 NAME 🌸

iptunnel_pmtud_build_icmpv6 — literally just Build ICMPv6 error message for PMTUD. no cap, that's what she does. 👑

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🦋 SYNOPSIS 🦋

int iptunnel_pmtud_build_icmpv6 (struct sk_buff *skb , int mtu );

she takes two things and hands you back an int. that's the whole signature, copy it exactly bestie, don't freestyle it 💅

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💖 ARGUMENTS 💖

• skb — the Original packet with L2 header. like, the packet with its L2 header still on it, okay? don't come at her with a stripped-down skb and expect magic 🙈
• mtu — the MTU value for the ICMPv6 error. this is the number she's gonna put in the message. 🍓

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⭐ RETURN ⭐

she returns the length on success — slay 💅 — or a negative error code if the message couldn't be built. so if you get a negative number back, that's her telling you it did not work out, and you should probably go touch some grass and then debug it 😭

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🔥 SEE ALSO 🔥

• the kernel file ./net/ipv4/ip_tunnel_core.c — that's where the lore lives 📖
• iptunnel_pmtud_build_icmp(9)
• iptunnel_pmtud_check_icmp(9)
• iptunnel_pmtud_check_icmpv6(9)
• skb_tunnel_check_pmtu(9)

the whole friend group fr fr 🫶

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heads up: this is kernel API territory, section 9, so please read the actual kernel source before you go shipping anything. the vibes are immaculate but the vibes are not documentation 💀

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and that's the page!! 🧚 mwah 💜 this one came out of ./net/ipv4, dated October 2026, and it's the iptunnel_pmtud_build_icmpv6(9) manual page — go build some ICMPv6 errors responsibly bestie 🌈✨🎀