IF_ADDRHOOK_ADD(9)

💖 IF_ADDRHOOK_ADD(9) — Kernel Developer's Manual ✨

okay so bestie, this is the whole interface event hook API situation, and it’s lowkey iconic kernel-dev energy 💅

🌸 NAME 🌸

if_addrhook_add, if_addrhook_del, if_detachhook_add, if_detachhook_del, if_linkstatehook_add, if_linkstatehook_del — interface event hook API

🦋 SYNOPSIS 🦋

#include <net/if_var.h>

void
if_addrhook_add(struct ifnet *ifp, struct task *t);

void
if_addrhook_del(struct ifnet *ifp, struct task *t);

void
if_detachhook_add(struct ifnet *ifp, struct task *t);

void
if_detachhook_del(struct ifnet *ifp, struct task *t);

void
if_linkstatehook_add(struct ifnet *ifp, struct task *t);

void
if_linkstatehook_del(struct ifnet *ifp, struct task *t);

✨ DESCRIPTION ✨

The interface hook API allows for the registration of a task that will be called when an IP address change, link state, or detach event occurs on the specified interface. Tasks should be initialised with task_add(9) or TASK_INITIALIZER(9) before being used with the following functions, bestie — like, do the setup first, then slay 🫶

• if_addrhook_add() — registers the task t on the ifp interface. The event will fire every time an IPv4 or IPv6 address change occurs on the interface, until explicitly removed with if_addrhook_del(). It’s giving “address changes? I’m watching 👀✨”
• if_addrhook_del() — removes the task t from the ifp interface. bye bestie 👋
• if_detachhook_add() — registers the task t on the ifp interface. The event will fire when the interface is being destroyed. dramatic, but necessary 💀
• if_detachhook_del() — removes the task t from the ifp interface.
• if_linkstatehook_add() — registers the task t on the ifp interface. The event will fire for every link state change, or when the interface is brought up or down, until explicitly removed with if_linkstatehook_del(). link-state main character behavior, fr fr 🌈
• if_linkstatehook_del() — removes the task t from the ifp interface.

🌟 CONTEXT 🌟

if_addrhook_add(), if_addrhook_del(), if_detachhook_add(), if_detachhook_del(), if_linkstatehook_add(), and if_linkstatehook_del() can be called during autoconf, from process context, or from interrupt context. so yes, they can show up in all those places — no cap 💫

🔎 SEE ALSO 🔎

• task_set(9) — go peek, iykyk 🎀

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xoxo, Debian — February 22, 2024 💖