145 lines
3.3 KiB
Go
145 lines
3.3 KiB
Go
// Package telnet provides some fancy tools, like an ASCII-art stream.
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package telnet
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import (
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"io"
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"log"
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"net"
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"strings"
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"time"
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)
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var (
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// Cfg contains the different options of the telnet package, see below
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// TODO Config should not be exported
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Cfg *Options
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currentMessage map[string]*string
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)
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// Options holds telnet package configuration
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type Options struct {
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Enabled bool
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ListenAddress string
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Width int
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Height int
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Delay int
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}
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// Serve starts the telnet server and listen to clients
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func Serve(config *Options) {
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Cfg = config
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if !Cfg.Enabled {
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return
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}
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currentMessage = make(map[string]*string)
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listener, err := net.Listen("tcp", Cfg.ListenAddress)
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if err != nil {
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log.Printf("Error while listening to the address %s: %s", Cfg.ListenAddress, err)
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return
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}
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go func() {
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for {
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s, err := listener.Accept()
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if err != nil {
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log.Printf("Error while accepting TCP socket: %s", s)
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continue
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}
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go func(s net.Conn) {
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streamID := ""
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// Request for stream ID
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for {
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_, _ = s.Write([]byte("[GHOSTREAM]\n"))
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_, err = s.Write([]byte("Enter stream ID: "))
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if err != nil {
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log.Println("Error while requesting stream ID to telnet client")
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_ = s.Close()
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return
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}
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buff := make([]byte, 255)
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n, err := s.Read(buff)
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if err != nil {
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log.Println("Error while requesting stream ID to telnet client")
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_ = s.Close()
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return
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}
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streamID = string(buff[:n])
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streamID = strings.Replace(streamID, "\r", "", -1)
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streamID = strings.Replace(streamID, "\n", "", -1)
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if len(streamID) > 0 {
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if strings.ToLower(streamID) == "exit" {
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_, _ = s.Write([]byte("Goodbye!\n"))
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_ = s.Close()
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return
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}
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if _, ok := currentMessage[streamID]; !ok {
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_, err = s.Write([]byte("Unknown stream ID.\n"))
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if err != nil {
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log.Println("Error while requesting stream ID to telnet client")
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_ = s.Close()
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return
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}
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continue
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}
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break
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}
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}
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for {
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n, err := s.Write([]byte(*currentMessage[streamID]))
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if err != nil {
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log.Printf("Error while sending TCP data: %s", err)
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_ = s.Close()
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break
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}
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if n == 0 {
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_ = s.Close()
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break
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}
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time.Sleep(time.Duration(Cfg.Delay) * time.Millisecond)
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}
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}(s)
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}
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}()
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log.Println("Telnet server initialized")
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}
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func asciiChar(pixel byte) string {
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asciiChars := []string{"@", "#", "$", "%", "?", "*", "+", ";", ":", ",", ".", " "}
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return asciiChars[(255-pixel)/22]
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}
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// StartASCIIArtStream send all packets received by ffmpeg as ASCII Art to telnet clients
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func StartASCIIArtStream(streamID string, reader io.ReadCloser) {
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if !Cfg.Enabled {
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_ = reader.Close()
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return
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}
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currentMessage[streamID] = new(string)
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buff := make([]byte, Cfg.Width*Cfg.Height)
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header := "\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"
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for {
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n, _ := reader.Read(buff)
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if n == 0 {
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break
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}
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imageStr := ""
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for j := 0; j < Cfg.Height; j++ {
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for i := 0; i < Cfg.Width; i++ {
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pixel := buff[Cfg.Width*j+i]
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imageStr += asciiChar(pixel) + asciiChar(pixel)
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}
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imageStr += "\n"
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}
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*(currentMessage[streamID]) = header + imageStr
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}
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}
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