Woo it's so fast.

go.mod

@@ -0,0 +1,3 @@
+module github.com/ajmadsen/jingleping-go
+
+require golang.org/x/net v0.0.0-20181220203305-927f97764cc3

go.sum

@@ -0,0 +1,2 @@
+golang.org/x/net v0.0.0-20181220203305-927f97764cc3 h1:eH6Eip3UpmR+yM/qI9Ijluzb1bNv/cAU/n+6l8tRSis=
+golang.org/x/net v0.0.0-20181220203305-927f97764cc3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=

main.go

@@ -0,0 +1,136 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"image"
+	"log"
+	"net"
+	"os"
+	"os/signal"
+	"time"
+
+	_ "image/gif"
+	_ "image/jpeg"
+	_ "image/png"
+
+	"golang.org/x/net/icmp"
+	"golang.org/x/net/ipv6"
+)
+
+var (
+	dstNetFlag  = flag.String("dst-net", "2001:4c08:2028", "the destination network of the ipv6 tree")
+	imageFlag   = flag.String("image", "", "the image to ping to the tree")
+	xOffFlag    = flag.Int("x", 0, "the x offset to draw the image")
+	yOffFlag    = flag.Int("y", 0, "the y offset to draw the image")
+	rateFlag    = flag.Int("rate", 100, "how many times to draw the image per second")
+	workersFlag = flag.Int("workers", 1, "the number of workers to use")
+)
+
+const (
+	maxX = 160
+	maxY = 120
+)
+
+var pingPacket []byte
+
+func worker(ch <-chan *net.IPAddr) {
+	c, err := icmp.ListenPacket("ip6:ipv6-icmp", "::")
+	if err != nil {
+		log.Fatalf("could not open ping socket: %s", err)
+	}
+	log.Printf("starting worker")
+
+	for {
+		for a := range ch {
+			_, err = c.WriteTo(pingPacket, a)
+			if err != nil {
+				log.Printf("warning: could not send ping packet: %s", err)
+			}
+		}
+	}
+}
+
+func fill(ch chan<- *net.IPAddr, addr []*net.IPAddr, rate int) {
+	// pixel clock
+	sd := 1 * time.Second / time.Duration(rate)
+	ticker := time.NewTicker(sd)
+
+	for {
+		for _, a := range addr {
+			ch <- a
+		}
+		<-ticker.C
+	}
+}
+
+func makeAddrs(img image.Image, dstNet string, xOff, yOff int) []*net.IPAddr {
+	var addrs []*net.IPAddr
+
+	bounds := img.Bounds()
+	for y := 0; y < bounds.Dy() && y+yOff < maxY; y++ {
+		for x := 0; x < bounds.Dx() && x+xOff < maxX; x++ {
+			r, g, b, a := img.At(x, y).RGBA()
+			if a > 0 {
+				addrs = append(addrs, &net.IPAddr{
+					IP: net.ParseIP(fmt.Sprintf("%s:%d:%d:%x:%x:%x", dstNet, x+xOff, y+yOff, r>>8, g>>8, b>>8)),
+				})
+			}
+		}
+	}
+
+	return addrs
+}
+
+func main() {
+	flag.Parse()
+
+	if *imageFlag == "" {
+		fmt.Fprintln(os.Stderr, "the image flag must be provided")
+		os.Exit(1)
+	}
+
+	f, err := os.Open(*imageFlag)
+	if err != nil {
+		log.Fatalf("could not open image: %s", err)
+	}
+
+	img, _, err := image.Decode(f)
+	if err != nil {
+		log.Fatalf("could not decode image: %s", err)
+	}
+
+	addrs := makeAddrs(img, *dstNetFlag, *xOffFlag, *yOffFlag)
+	log.Printf("num addrs: %d", len(addrs))
+
+	pixCh := make(chan *net.IPAddr, len(addrs))
+	go fill(pixCh, addrs, *rateFlag)
+
+	for i := 0; i < *workersFlag; i++ {
+		go worker(pixCh)
+	}
+
+	ch := make(chan os.Signal, 1)
+	signal.Notify(ch, os.Interrupt)
+	<-ch
+	log.Println("exiting...")
+}
+
+// Setup ping packet
+func init() {
+	var err error
+
+	p := &icmp.Message{
+		Type: ipv6.ICMPTypeEchoRequest,
+		Code: 0,
+		Body: &icmp.Echo{
+			ID:  0xDEAD,
+			Seq: 1,
+		},
+	}
+
+	pingPacket, err = p.Marshal(nil)
+	if err != nil {
+		panic(err)
+	}
+}