Implementing ICMP ping in Go

Question

Is it possible to implement an ICMP ping in Go? The alternative is to fork a 'ping' process, but I'd rather write it in Go.

Answer 1

The following code shows how to perform a ping over IPv4 using a raw socket (requires root privs):

package main

import (
    "log"
    "net"
    "os"

    "golang.org/x/net/icmp"
    "golang.org/x/net/ipv4"
)

const targetIP = "8.8.8.8"

func main() {
    c, err := icmp.ListenPacket("ip4:icmp", "0.0.0.0")
    if err != nil {
        log.Fatalf("listen err, %s", err)
    }
    defer c.Close()

    wm := icmp.Message{
        Type: ipv4.ICMPTypeEcho, Code: 0,
        Body: &icmp.Echo{
            ID: os.Getpid() & 0xffff, Seq: 1,
            Data: []byte("HELLO-R-U-THERE"),
        },
    }
    wb, err := wm.Marshal(nil)
    if err != nil {
        log.Fatal(err)
    }
    if _, err := c.WriteTo(wb, &net.IPAddr{IP: net.ParseIP(targetIP)}); err != nil {
        log.Fatalf("WriteTo err, %s", err)
    }

    rb := make([]byte, 1500)
    n, peer, err := c.ReadFrom(rb)
    if err != nil {
        log.Fatal(err)
    }
    rm, err := icmp.ParseMessage(ipv4.ICMPTypeEchoReply.Protocol(), rb[:n])
    if err != nil {
        log.Fatal(err)
    }
    switch rm.Type {
    case ipv4.ICMPTypeEchoReply:
        log.Printf("got reflection from %v", peer)
    default:
        log.Printf("got %+v; want echo reply", rm)
    }
}

Code based on the example found here: https://godoc.org/golang.org/x/net/icmp#PacketConn

In order to ping from Linux as a non-privileged user, see this post

Answer 2

Currently, the ICMP Echo (Ping) function isn't supported in the Go net package.

There's no support for sending ICMP echo requests. You'd have to add support to package net. ping