func icmpSendMsg()

in client.go [841:879]
37 lines of code
6 McCabe index (conditional complexity)

func icmpSendMsg(c net.PacketConn, dstIPAddr net.IPAddr, hop, seq int, body string, timeout time.Duration) (time.Time, []byte, error) {
	start := time.Now()
	err := icmpSetTTL(c, hop+1)
	if err != nil {
		ui.printErr("Failed to set TTL. Error: %v", err)
		return start, nil, err
	}
	icmpSetTOS(c, int(gTOS))

	err = c.SetDeadline(time.Now().Add(timeout))
	if err != nil {
		ui.printErr("Failed to set Deadline. Error: %v", err)
		return start, nil, err
	}

	pid := os.Getpid() & 0xffff
	pid = 9999
	wm := icmp.Message{
		Type: ipv4.ICMPTypeEcho, Code: 0,
		Body: &icmp.Echo{
			ID: pid, Seq: hop<<8 | seq,
			Data: []byte(body),
		},
	}
	if gIPVersion == ethrIPv6 {
		wm.Type = ipv6.ICMPTypeEchoRequest
	}
	wb, err := wm.Marshal(nil)
	if err != nil {
		ui.printErr("Failed to Marshal data. Error: %v", err)
		return start, nil, err
	}
	start = time.Now()
	if _, err := c.WriteTo(wb, &dstIPAddr); err != nil {
		ui.printErr("Failed to send ICMP data. Error: %v", err)
		return start, nil, err
	}
	return start, wb, nil
}