uevent

README

Golang uevent bindings

This golang library implements uevent bindings for reading and decoding Linux kernel udev events.

Usage

package main

import (
	"fmt"
	"log"

	"github.com/s-urbaniak/uevent"
)

func main() {
	r, err := uevent.NewReader()
	if err != nil {
		log.Fatal(err)
	}

	dec := uevent.NewDecoder(r)

	for {
		evt, err := dec.Decode()
		if err != nil {
			log.Fatal(err)
		}
		fmt.Println(evt)
	}
}

Prerequisites

Linux

Documentation

Overview

Package uevent implements a Linux kernel uevent reader and decoder. The reader uses a Netlink (AF_NETLINK) socket to listen to kernel udev events (see netlink(7)). The decoder takes an arbitrary io.Reader and decodes Uevent objects.

Index

• Constants
• func NewReader() (io.ReadCloser, error)
• type Decoder
  • func NewDecoder(r io.Reader) *Decoder
  • func (d *Decoder) Decode() (*Uevent, error)
• type Reader
  • func (r *Reader) Close() error
  • func (r *Reader) Read(p []byte) (n int, err error)
• type Uevent

Constants

const NETLINK_KOBJECT_UEVENT = 15

NETLINK_KOBJECT_UEVENT is the socket protocol for kernel uevent, see /usr/include/linux/netlink.h

Functions

func NewReader

func NewReader() (io.ReadCloser, error)

NewReader returns a new netlink socket reader. It opens a raw AF_NETLINK domain socket using the uevent protocol and binds it to the PID of the calling program.

Types

type Decoder

type Decoder struct {
	// contains filtered or unexported fields
}

Decoder decodes uevents from a reader.

func NewDecoder

func NewDecoder(r io.Reader) *Decoder

NewDecoder creates an uevent decoder using the given reader to read uevents from.

func (*Decoder) Decode

func (d *Decoder) Decode() (*Uevent, error)

Decode blocks until the uext uevent happens, decodes and returns it. It is meant to be used in a loop.

type Reader

type Reader struct {
	// contains filtered or unexported fields
}

Reader implements reading uevents from an AF_NETLINK socket.

func (*Reader) Close

func (r *Reader) Close() error

Close closes the underlying netlink socket.

func (*Reader) Read

func (r *Reader) Read(p []byte) (n int, err error)

Read reads from the underlying netlink socket. Trying to read from a closed reader return io.EOF.

type Uevent

type Uevent struct {
	Header string

	// default uevent variables as per kobject_uevent.c
	Action    string
	Devpath   string
	Subsystem string
	Seqnum    string

	// A key/value map of all variables
	Vars map[string]string
}

Uevent represents a single uevent.