Restructure telnet package

This commit is contained in:
Alexandre Iooss 2020-10-17 18:12:25 +02:00
parent f0990a630d
commit 88dfc22d81
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GPG Key ID: 6C79278F3FCDCC02
5 changed files with 238 additions and 165 deletions

103
stream/telnet/convert.go Normal file
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@ -0,0 +1,103 @@
package telnet
import (
"bufio"
"bytes"
"fmt"
"io"
"log"
"os/exec"
"gitlab.crans.org/nounous/ghostream/stream"
)
// Convert rawvideo to ANSI text
func streamToTextStream(stream *stream.Stream, text *[]byte, cfg *Options) {
// Start ffmpeg
video := make(chan []byte)
stream.Register(video)
_, rawvideo, err := startFFmpeg(video, cfg)
if err != nil {
log.Printf("Error while starting ffmpeg: %s", err)
}
pixelBuff := make([]byte, cfg.Width*cfg.Height)
textBuff := bytes.Buffer{}
for {
n, err := (*rawvideo).Read(pixelBuff)
if err != nil {
log.Printf("An error occurred while reading input: %s", err)
break
}
if n == 0 {
// Stream is finished
break
}
// Header
textBuff.Reset()
textBuff.Grow((40*cfg.Width+6)*cfg.Height + 47)
for i := 0; i < 42; i++ {
textBuff.WriteByte('\n')
}
// Convert image to ASCII
for i, pixel := range pixelBuff {
if i%cfg.Width == 0 {
// New line
textBuff.WriteString("\033[49m\n")
}
// Print two times the character to make a square
text := fmt.Sprintf("\033[48;2;%d;%d;%dm ", pixel, pixel, pixel)
textBuff.WriteString(text)
textBuff.WriteString(text)
}
textBuff.WriteString("\033[49m")
*text = textBuff.Bytes()
}
}
// Start a ffmpeg instance to convert stream into rawvideo
func startFFmpeg(in <-chan []byte, cfg *Options) (*exec.Cmd, *io.ReadCloser, error) {
bitrate := fmt.Sprintf("%dk", cfg.Width*cfg.Height/cfg.Delay)
ffmpegArgs := []string{"-hide_banner", "-loglevel", "error", "-i", "pipe:0",
"-an", "-vf", fmt.Sprintf("scale=%dx%d", cfg.Width, cfg.Height),
"-b:v", bitrate, "-minrate", bitrate, "-maxrate", bitrate, "-bufsize", bitrate,
"-q", "42", "-pix_fmt", "gray", "-f", "rawvideo", "pipe:1"}
ffmpeg := exec.Command("ffmpeg", ffmpegArgs...)
// Handle errors output
errOutput, err := ffmpeg.StderrPipe()
if err != nil {
return nil, nil, err
}
go func() {
scanner := bufio.NewScanner(errOutput)
for scanner.Scan() {
log.Printf("[TELNET FFMPEG %s] %s", "demo", scanner.Text())
}
}()
// Handle text output
output, err := ffmpeg.StdoutPipe()
if err != nil {
return nil, nil, err
}
// Handle stream input
input, err := ffmpeg.StdinPipe()
if err != nil {
return nil, nil, err
}
go func() {
for data := range in {
input.Write(data)
}
}()
// Start process
err = ffmpeg.Start()
return ffmpeg, &output, nil
}

82
stream/telnet/handler.go Normal file
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@ -0,0 +1,82 @@
package telnet
import (
"log"
"net"
"strings"
"time"
"gitlab.crans.org/nounous/ghostream/stream"
)
func handleViewer(s net.Conn, streams map[string]*stream.Stream, textStreams map[string]*[]byte, cfg *Options) {
// Prompt user about stream name
if _, err := s.Write([]byte("[GHOSTREAM]\nEnter stream name: ")); err != nil {
log.Printf("Error while writing to TCP socket: %s", err)
s.Close()
return
}
buff := make([]byte, 255)
n, err := s.Read(buff)
if err != nil {
log.Printf("Error while requesting stream ID to telnet client: %s", err)
s.Close()
return
}
name := strings.TrimSpace(string(buff[:n]))
if len(name) < 1 {
// Too short, exit
s.Close()
return
}
// Wait a bit
time.Sleep(time.Second)
// Get requested stream
st, ok := streams[name]
if !ok {
log.Println("Stream does not exist, kicking new Telnet viewer")
if _, err := s.Write([]byte("This stream is inactive.\n")); err != nil {
log.Printf("Error while writing to TCP socket: %s", err)
}
s.Close()
return
}
// Register new client
log.Printf("New Telnet viewer for stream %s", name)
st.IncrementClientCount()
// Hide terminal cursor
if _, err = s.Write([]byte("\033[?25l")); err != nil {
log.Printf("Error while writing to TCP socket: %s", err)
s.Close()
return
}
// Send stream
for {
text, ok := textStreams[name]
if !ok {
log.Println("Stream is not converted to text, kicking Telnet viewer")
if _, err := s.Write([]byte("This stream cannot be opened.\n")); err != nil {
log.Printf("Error while writing to TCP socket: %s", err)
}
break
}
// Send text to client
n, err := s.Write(*text)
if err != nil || n == 0 {
log.Printf("Error while sending TCP data: %s", err)
break
}
time.Sleep(time.Duration(cfg.Delay) * time.Millisecond)
}
// Close connection
s.Close()
st.DecrementClientCount()
}

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@ -2,20 +2,11 @@
package telnet
import (
"fmt"
"io"
"log"
"net"
"strings"
"time"
)
var (
// Cfg contains the different options of the telnet package, see below
// TODO Config should not be exported
Cfg *Options
currentMessage map[string]*string
clientCount map[string]int
"gitlab.crans.org/nounous/ghostream/stream"
)
// Options holds telnet package configuration
@ -27,152 +18,52 @@ type Options struct {
Delay int
}
// Serve starts the telnet server and listen to clients
func Serve(config *Options) {
Cfg = config
if !config.Enabled {
// Serve Telnet server
func Serve(streams map[string]*stream.Stream, cfg *Options) {
if !cfg.Enabled {
// Telnet is not enabled, ignore
return
}
currentMessage = make(map[string]*string)
clientCount = make(map[string]int)
// Start conversion routine
textStreams := make(map[string]*[]byte)
go autoStartConversion(streams, textStreams, cfg)
listener, err := net.Listen("tcp", config.ListenAddress)
// Start TCP server
listener, err := net.Listen("tcp", cfg.ListenAddress)
if err != nil {
log.Printf("Error while listening to the address %s: %s", config.ListenAddress, err)
return
log.Fatalf("Error while listening to the address %s: %s", cfg.ListenAddress, err)
}
log.Printf("Telnet server listening on %s", cfg.ListenAddress)
go func() {
for {
s, err := listener.Accept()
if err != nil {
log.Printf("Error while accepting TCP socket: %s", s)
// Handle each new client
for {
s, err := listener.Accept()
if err != nil {
log.Printf("Error while accepting TCP socket: %s", s)
continue
}
go handleViewer(s, streams, textStreams, cfg)
}
}
// Convertion routine listen to existing stream and start text conversions
func autoStartConversion(streams map[string]*stream.Stream, textStreams map[string]*[]byte, cfg *Options) {
for {
for name, stream := range streams {
textStream, ok := textStreams[name]
if ok {
// Everything is fine
continue
}
go func(s net.Conn) {
streamID := ""
// Request for stream ID
for {
_, err = s.Write([]byte("[GHOSTREAM]\nEnter stream ID: "))
if err != nil {
log.Println("Error while requesting stream ID to telnet client")
_ = s.Close()
return
}
buff := make([]byte, 255)
n, err := s.Read(buff)
if err != nil {
log.Println("Error while requesting stream ID to telnet client")
_ = s.Close()
return
}
// Avoid bruteforce
time.Sleep(3 * time.Second)
streamID = string(buff[:n])
streamID = strings.Replace(streamID, "\r", "", -1)
streamID = strings.Replace(streamID, "\n", "", -1)
if len(streamID) > 0 {
if strings.ToLower(streamID) == "exit" {
_, _ = s.Write([]byte("Goodbye!\n"))
_ = s.Close()
return
}
if _, ok := currentMessage[streamID]; !ok {
_, err = s.Write([]byte("Unknown stream ID.\n"))
if err != nil {
log.Println("Error while requesting stream ID to telnet client")
_ = s.Close()
return
}
continue
}
break
}
}
clientCount[streamID]++
// Hide terminal cursor
_, _ = s.Write([]byte("\033[?25l"))
for {
n, err := s.Write([]byte(*currentMessage[streamID]))
if err != nil {
log.Printf("Error while sending TCP data: %s", err)
_ = s.Close()
clientCount[streamID]--
break
}
if n == 0 {
_ = s.Close()
clientCount[streamID]--
break
}
time.Sleep(time.Duration(config.Delay) * time.Millisecond)
}
}(s)
// Start conversion
log.Print("Starting text conversion of %s", name)
textStream = &[]byte{}
textStreams[name] = textStream
go streamToTextStream(stream, textStream, cfg)
}
}()
log.Println("Telnet server initialized")
}
// GetNumberConnectedSessions returns the numbers of clients that are viewing the stream through a telnet shell
func GetNumberConnectedSessions(streamID string) int {
if Cfg == nil || !Cfg.Enabled {
return 0
}
return clientCount[streamID]
}
// StartASCIIArtStream send all packets received by ffmpeg as ASCII Art to telnet clients
func StartASCIIArtStream(streamID string, reader io.ReadCloser) {
if !Cfg.Enabled {
_ = reader.Close()
return
}
currentMessage[streamID] = new(string)
pixelBuff := make([]byte, Cfg.Width*Cfg.Height)
textBuff := strings.Builder{}
for {
n, err := reader.Read(pixelBuff)
if err != nil {
log.Printf("An error occurred while reading input: %s", err)
break
}
if n == 0 {
// Stream is finished
break
}
// Header
textBuff.Reset()
textBuff.Grow((40*Cfg.Width+6)*Cfg.Height + 47)
for i := 0; i < 42; i++ {
textBuff.WriteByte('\n')
}
// Convert image to ASCII
for i, pixel := range pixelBuff {
if i%Cfg.Width == 0 {
// New line
textBuff.WriteString("\033[49m\n")
}
// Print two times the character to make a square
text := fmt.Sprintf("\033[48;2;%d;%d;%dm ", pixel, pixel, pixel)
textBuff.WriteString(text)
textBuff.WriteString(text)
}
textBuff.WriteString("\033[49m")
*(currentMessage[streamID]) = textBuff.String()
time.Sleep(time.Second)
}
}

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@ -1,41 +1,38 @@
package telnet
import (
"bytes"
"io/ioutil"
"math/rand"
"net"
"testing"
"time"
"gitlab.crans.org/nounous/ghostream/stream"
)
// TestTelnetOutput creates a TCP client that connects to the server and get one image.
func TestTelnetOutput(t *testing.T) {
// Try to start Telnet server while it is disabled
Serve(&Options{Enabled: false})
StartASCIIArtStream("demo", ioutil.NopCloser(bytes.NewReader([]byte{})))
if GetNumberConnectedSessions("demo") != 0 {
t.Fatalf("Mysteriously found %d connected clients", GetNumberConnectedSessions("demo"))
}
streams := make(map[string]*stream.Stream)
go Serve(streams, &Options{Enabled: false})
// FIXME test connect
// Enable and start Telnet server
Serve(&Options{
cfg := Options{
Enabled: true,
ListenAddress: "127.0.0.1:8023",
Width: 80,
Height: 45,
Delay: 50,
})
}
go Serve(streams, &cfg)
// FIXME test connect
// Generate a random image, that should be given by FFMPEG
sampleImage := make([]byte, Cfg.Width*Cfg.Height)
/*sampleImage := make([]byte, cfg.Width*cfg.Height)
rand.Read(sampleImage)
reader := ioutil.NopCloser(bytes.NewBuffer(sampleImage))
// Send the image to the server
StartASCIIArtStream("demo", reader)
// Connect to the Telnet server
client, err := net.Dial("tcp", Cfg.ListenAddress)
client, err := net.Dial("tcp", cfg.ListenAddress)
if err != nil {
t.Fatalf("Error while connecting to the TCP server: %s", err)
}
@ -46,7 +43,7 @@ func TestTelnetOutput(t *testing.T) {
t.Fatalf("Error while closing TCP connection: %s", err)
}
client, err = net.Dial("tcp", Cfg.ListenAddress)
client, err = net.Dial("tcp", cfg.ListenAddress)
if err != nil {
t.Fatalf("Error while connecting to the TCP server: %s", err)
}
@ -110,5 +107,5 @@ func TestTelnetOutput(t *testing.T) {
time.Sleep(time.Second)
if GetNumberConnectedSessions("demo") != 0 {
t.Fatalf("Expected no telnet client, found %d", GetNumberConnectedSessions("demo"))
}
}*/
}

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@ -157,7 +157,7 @@ func statisticsHandler(w http.ResponseWriter, r *http.Request) {
stream, ok := streams[name]
if ok {
// Get number of output channels
userCount = stream.Count()
userCount = stream.ClientCount()
}
// Display connected users statistics