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refactor: separate session responsibilities and inject dependencies
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This commit is contained in:
bagas
2025-11-28 13:29:43 +07:00
parent 9c4ac732ee
commit d3a5007d68
6 changed files with 521 additions and 360 deletions
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427
session/handler.go
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@ -11,7 +11,6 @@ import (
"log"
"net"
"strconv"
"strings"
"sync"
"time"
portUtil "tunnel_pls/internal/port"
@ -34,10 +33,10 @@ type UserConnection struct {
var (
clientsMutex sync.RWMutex
Clients = make(map[string]*Session)
Clients = make(map[string]*SSHSession)
)
func registerClient(slug string, session *Session) bool {
func registerClient(slug string, session *SSHSession) bool {
clientsMutex.Lock()
defer clientsMutex.Unlock()
@ -56,53 +55,35 @@ func unregisterClient(slug string) {
delete(Clients, slug)
}
func updateClientSlug(oldSlug, newSlug string) bool {
clientsMutex.Lock()
defer clientsMutex.Unlock()
if _, exists := Clients[newSlug]; exists && newSlug != oldSlug {
return false
}
client, ok := Clients[oldSlug]
if !ok {
return false
}
delete(Clients, oldSlug)
client.Slug = newSlug
Clients[newSlug] = client
return true
}
func (s *Session) Close() error {
if s.Listener != nil {
err := s.Listener.Close()
func (s *SSHSession) Close() error {
if s.forwarder.Listener != nil {
err := s.forwarder.Listener.Close()
if err != nil && !errors.Is(err, net.ErrClosed) {
return err
}
}
if s.ConnChannel != nil {
err := s.ConnChannel.Close()
if s.channel != nil {
err := s.channel.Close()
if err != nil && !errors.Is(err, io.EOF) {
return err
}
}
if s.Connection != nil {
err := s.Connection.Close()
if s.Conn != nil {
err := s.Conn.Close()
if err != nil && !errors.Is(err, net.ErrClosed) {
return err
}
}
if s.Slug != "" {
unregisterClient(s.Slug)
slug := s.forwarder.getSlug()
if slug != "" {
unregisterClient(slug)
}
if s.TunnelType == TCP {
err := portUtil.Manager.SetPortStatus(s.ForwardedPort, false)
if s.forwarder.TunnelType == TCP && s.forwarder.Listener != nil {
err := portUtil.Manager.SetPortStatus(s.forwarder.ForwardedPort, false)
if err != nil {
return err
}
@ -111,7 +92,7 @@ func (s *Session) Close() error {
return nil
}
func (s *Session) HandleGlobalRequest(GlobalRequest <-chan *ssh.Request) {
func (s *SSHSession) HandleGlobalRequest(GlobalRequest <-chan *ssh.Request) {
for req := range GlobalRequest {
switch req.Type {
case "tcpip-forward":
@ -126,7 +107,7 @@ func (s *Session) HandleGlobalRequest(GlobalRequest <-chan *ssh.Request) {
}
}
func (s *Session) handleTCPIPForward(req *ssh.Request) {
func (s *SSHSession) handleTCPIPForward(req *ssh.Request) {
log.Println("Port forwarding request detected")
reader := bytes.NewReader(req.Payload)
@ -135,39 +116,50 @@ func (s *Session) handleTCPIPForward(req *ssh.Request) {
if err != nil {
log.Println("Failed to read address from payload:", err)
req.Reply(false, nil)
s.Close()
err := s.Close()
if err != nil {
log.Printf("failed to close session: %v", err)
}
return
}
var rawPortToBind uint32
if err := binary.Read(reader, binary.BigEndian, &rawPortToBind); err != nil {
log.Println("Failed to read port from payload:", err)
s.sendMessage(fmt.Sprintf("Port %d is already in use or restricted. Please choose a different port. (02) \r\n", rawPortToBind))
s.interaction.SendMessage(fmt.Sprintf("Port %d is already in use or restricted. Please choose a different port. (02) \r\n", rawPortToBind))
req.Reply(false, nil)
s.Close()
err := s.Close()
if err != nil {
log.Printf("failed to close session: %v", err)
}
return
}
if rawPortToBind > 65535 {
s.sendMessage(fmt.Sprintf("Port %d is larger then allowed port of 65535. (02)\r\n", rawPortToBind))
s.interaction.SendMessage(fmt.Sprintf("Port %d is larger then allowed port of 65535. (02)\r\n", rawPortToBind))
req.Reply(false, nil)
s.Close()
err := s.Close()
if err != nil {
log.Printf("failed to close session: %v", err)
}
return
}
portToBind := uint16(rawPortToBind)
if isBlockedPort(portToBind) {
s.sendMessage(fmt.Sprintf("Port %d is already in use or restricted. Please choose a different port. (02)\r\n", portToBind))
s.interaction.SendMessage(fmt.Sprintf("Port %d is already in use or restricted. Please choose a different port. (02)\r\n", portToBind))
req.Reply(false, nil)
s.Close()
err := s.Close()
if err != nil {
log.Printf("failed to close session: %v", err)
}
return
}
s.sendMessage("\033[H\033[2J")
s.Status = RUNNING
showWelcomeMessage(s.ConnChannel)
go s.handleUserInput()
s.interaction.SendMessage("\033[H\033[2J")
s.lifecycle.Status = RUNNING
go s.interaction.HandleUserInput()
if portToBind == 80 || portToBind == 443 {
s.handleHTTPForward(req, portToBind)
@ -177,15 +169,21 @@ func (s *Session) handleTCPIPForward(req *ssh.Request) {
unassign, success := portUtil.Manager.GetUnassignedPort()
portToBind = unassign
if !success {
s.sendMessage(fmt.Sprintf("No available port\r\n", portToBind))
s.interaction.SendMessage(fmt.Sprintf("No available port\r\n", portToBind))
req.Reply(false, nil)
s.Close()
err := s.Close()
if err != nil {
log.Printf("failed to close session: %v", err)
}
return
}
} else if isUse, isExist := portUtil.Manager.GetPortStatus(portToBind); !isExist || isUse {
s.sendMessage(fmt.Sprintf("Port %d is already in use or restricted. Please choose a different port. (03)\r\n", portToBind))
} else if isUse, isExist := portUtil.Manager.GetPortStatus(portToBind); isExist || isUse {
s.interaction.SendMessage(fmt.Sprintf("Port %d is already in use or restricted. Please choose a different port. (03)\r\n", portToBind))
req.Reply(false, nil)
s.Close()
err := s.Close()
if err != nil {
log.Printf("failed to close session: %v", err)
}
return
}
portUtil.Manager.SetPortStatus(portToBind, true)
@ -210,17 +208,17 @@ func isBlockedPort(port uint16) bool {
return false
}
func (s *Session) handleHTTPForward(req *ssh.Request, portToBind uint16) {
s.TunnelType = HTTP
s.ForwardedPort = uint16(portToBind)
func (s *SSHSession) handleHTTPForward(req *ssh.Request, portToBind uint16) {
s.forwarder.TunnelType = HTTP
s.forwarder.ForwardedPort = portToBind
slug := s.generateUniqueSlug()
slug := generateUniqueSlug()
if slug == "" {
req.Reply(false, nil)
return
}
s.Slug = slug
s.forwarder.setSlug(slug)
registerClient(slug, s)
buf := new(bytes.Buffer)
@ -233,24 +231,29 @@ func (s *Session) handleHTTPForward(req *ssh.Request, portToBind uint16) {
protocol = "https"
}
s.sendMessage(fmt.Sprintf("Forwarding your traffic to %s://%s.%s\r\n", protocol, slug, domain))
s.interaction.ShowWelcomeMessage()
s.interaction.SendMessage(fmt.Sprintf("Forwarding your traffic to %s://%s.%s\r\n", protocol, slug, domain))
req.Reply(true, buf.Bytes())
}
func (s *Session) handleTCPForward(req *ssh.Request, addr string, portToBind uint16) {
s.TunnelType = TCP
func (s *SSHSession) handleTCPForward(req *ssh.Request, addr string, portToBind uint16) {
s.forwarder.TunnelType = TCP
log.Printf("Requested forwarding on %s:%d", addr, portToBind)
listener, err := net.Listen("tcp", fmt.Sprintf("0.0.0.0:%d", portToBind))
if err != nil {
s.sendMessage(fmt.Sprintf("Port %d is already in use or restricted. Please choose a different port.\r\n", portToBind))
s.interaction.SendMessage(fmt.Sprintf("Port %d is already in use or restricted. Please choose a different port.\r\n", portToBind))
req.Reply(false, nil)
s.Close()
err := s.Close()
if err != nil {
log.Printf("failed to close session: %v", err)
}
return
}
s.Listener = listener
s.ForwardedPort = uint16(portToBind)
s.sendMessage(fmt.Sprintf("Forwarding your traffic to %s://%s:%d \r\n", s.TunnelType, utils.Getenv("domain"), s.ForwardedPort))
s.forwarder.Listener = listener
s.forwarder.ForwardedPort = portToBind
s.interaction.ShowWelcomeMessage()
s.interaction.SendMessage(fmt.Sprintf("Forwarding your traffic to %s://%s:%d \r\n", s.forwarder.TunnelType, utils.Getenv("domain"), s.forwarder.ForwardedPort))
go s.acceptTCPConnections()
@ -260,9 +263,9 @@ func (s *Session) handleTCPForward(req *ssh.Request, addr string, portToBind uin
req.Reply(true, buf.Bytes())
}
func (s *Session) acceptTCPConnections() {
func (s *SSHSession) acceptTCPConnections() {
for {
conn, err := s.Listener.Accept()
conn, err := s.forwarder.Listener.Accept()
if err != nil {
if errors.Is(err, net.ErrClosed) {
return
@ -274,11 +277,11 @@ func (s *Session) acceptTCPConnections() {
go s.HandleForwardedConnection(UserConnection{
Reader: nil,
Writer: conn,
}, s.Connection)
}, s.Conn)
}
}
func (s *Session) generateUniqueSlug() string {
func generateUniqueSlug() string {
maxAttempts := 5
for i := 0; i < maxAttempts; i++ {
@ -297,7 +300,7 @@ func (s *Session) generateUniqueSlug() string {
return ""
}
func (s *Session) waitForRunningStatus() {
func (s *SSHSession) waitForRunningStatus() {
timeout := time.After(3 * time.Second)
ticker := time.NewTicker(150 * time.Millisecond)
defer ticker.Stop()
@ -306,97 +309,25 @@ func (s *Session) waitForRunningStatus() {
for {
select {
case <-ticker.C:
s.sendMessage(fmt.Sprintf("\rLoading %s", frames[i]))
s.interaction.SendMessage(fmt.Sprintf("\rLoading %s", frames[i]))
i = (i + 1) % len(frames)
if s.Status == RUNNING {
if s.lifecycle.Status == RUNNING {
s.interaction.SendMessage("\r\033[K")
return
}
case <-timeout:
s.sendMessage("\r\033[K")
s.sendMessage("TCP/IP request not received in time.\r\nCheck your internet connection and confirm the server responds within 3000ms.\r\nEnsure you ran the correct command. For more details, visit https://tunnl.live.\r\n\r\n")
s.Close()
s.interaction.SendMessage("\r\033[K")
s.interaction.SendMessage("TCP/IP request not received in time.\r\nCheck your internet connection and confirm the server responds within 3000ms.\r\nEnsure you ran the correct command. For more details, visit https://tunnl.live.\r\n\r\n")
err := s.Close()
if err != nil {
log.Printf("failed to close session: %v", err)
}
log.Println("Timeout waiting for session to start running")
return
}
}
}
func (s *Session) sendMessage(message string) {
if s.ConnChannel != nil {
s.ConnChannel.Write([]byte(message))
}
}
func (s *Session) handleUserInput() {
var commandBuffer bytes.Buffer
buf := make([]byte, 1)
inSlugEditMode := false
editSlug := s.Slug
for {
n, err := s.ConnChannel.Read(buf)
if err != nil {
if err != io.EOF {
log.Printf("Error reading from client: %s", err)
}
break
}
if n > 0 {
char := buf[0]
if inSlugEditMode {
s.handleSlugEditMode(s.ConnChannel, &inSlugEditMode, &editSlug, char, &commandBuffer)
continue
}
s.ConnChannel.Write(buf[:n])
if char == 8 || char == 127 {
if commandBuffer.Len() > 0 {
commandBuffer.Truncate(commandBuffer.Len() - 1)
s.ConnChannel.Write([]byte("\b \b"))
}
continue
}
if char == '/' {
commandBuffer.Reset()
commandBuffer.WriteByte(char)
continue
}
if commandBuffer.Len() > 0 {
if char == 13 {
s.handleCommand(s.ConnChannel, commandBuffer.String(), &inSlugEditMode, &editSlug, &commandBuffer)
continue
}
commandBuffer.WriteByte(char)
}
}
}
}
func (s *Session) handleSlugEditMode(connection ssh.Channel, inSlugEditMode *bool, editSlug *string, char byte, commandBuffer *bytes.Buffer) {
if char == 13 {
s.handleSlugSave(connection, inSlugEditMode, editSlug, commandBuffer)
} else if char == 27 {
s.handleSlugCancel(connection, inSlugEditMode, commandBuffer)
} else if char == 8 || char == 127 {
if len(*editSlug) > 0 {
*editSlug = (*editSlug)[:len(*editSlug)-1]
connection.Write([]byte("\r\033[K"))
connection.Write([]byte("➤ " + *editSlug + "." + utils.Getenv("domain")))
}
} else if char >= 32 && char <= 126 {
if (char >= 'a' && char <= 'z') || (char >= '0' && char <= '9') || char == '-' {
*editSlug += string(char)
connection.Write([]byte("\r\033[K"))
connection.Write([]byte("➤ " + *editSlug + "." + utils.Getenv("domain")))
}
}
}
func isForbiddenSlug(slug string) bool {
for _, s := range forbiddenSlug {
if slug == s {
@ -406,77 +337,6 @@ func isForbiddenSlug(slug string) bool {
return false
}
func (s *Session) handleSlugSave(connection ssh.Channel, inSlugEditMode *bool, editSlug *string, commandBuffer *bytes.Buffer) {
isValid := isValidSlug(*editSlug)
connection.Write([]byte("\033[H\033[2J"))
if !isValid {
oldSlug := s.Slug
newSlug := *editSlug
if !updateClientSlug(oldSlug, newSlug) {
handleSlugUpdateError(connection, s)
return
}
connection.Write([]byte("\r\n\r\n✅ SUBDOMAIN UPDATED ✅\r\n\r\n"))
connection.Write([]byte("Your new address is: " + newSlug + "." + utils.Getenv("domain") + "\r\n\r\n"))
connection.Write([]byte("Press any key to continue...\r\n"))
} else if isForbiddenSlug(*editSlug) {
connection.Write([]byte("\r\n\r\n❌ FORBIDDEN SUBDOMAIN ❌\r\n\r\n"))
connection.Write([]byte("This subdomain is not allowed.\r\n"))
connection.Write([]byte("Please try a different subdomain.\r\n\r\n"))
connection.Write([]byte("Press any key to continue...\r\n"))
} else {
connection.Write([]byte("\r\n\r\n❌ INVALID SUBDOMAIN ❌\r\n\r\n"))
connection.Write([]byte("Use only lowercase letters, numbers, and hyphens.\r\n"))
connection.Write([]byte("Length must be 3-20 characters and cannot start or end with a hyphen.\r\n\r\n"))
connection.Write([]byte("Press any key to continue...\r\n"))
}
waitForKeyPress(connection)
connection.Write([]byte("\033[H\033[2J"))
showWelcomeMessage(connection)
domain := utils.Getenv("domain")
protocol := "http"
if utils.Getenv("tls_enabled") == "true" {
protocol = "https"
}
connection.Write([]byte(fmt.Sprintf("Forwarding your traffic to %s://%s.%s \r\n", protocol, s.Slug, domain)))
*inSlugEditMode = false
commandBuffer.Reset()
}
func (s *Session) handleSlugCancel(connection ssh.Channel, inSlugEditMode *bool, commandBuffer *bytes.Buffer) {
*inSlugEditMode = false
connection.Write([]byte("\033[H\033[2J"))
connection.Write([]byte("\r\n\r\n⚠️ SUBDOMAIN EDIT CANCELLED ⚠️\r\n\r\n"))
connection.Write([]byte("Press any key to continue...\r\n"))
waitForKeyPress(connection)
connection.Write([]byte("\033[H\033[2J"))
showWelcomeMessage(connection)
commandBuffer.Reset()
}
func handleSlugUpdateError(connection ssh.Channel, s *Session) {
connection.Write([]byte("\r\n\r\n❌ SERVER ERROR ❌\r\n\r\n"))
connection.Write([]byte("Failed to update subdomain. You will be disconnected in 5 seconds.\r\n\r\n"))
for i := 5; i > 0; i-- {
connection.Write([]byte(fmt.Sprintf("Disconnecting in %d...\r\n", i)))
time.Sleep(1 * time.Second)
}
s.Close()
}
func isValidSlug(slug string) bool {
if len(slug) < 3 || len(slug) > 20 {
return false
@ -505,47 +365,7 @@ func waitForKeyPress(connection ssh.Channel) {
}
}
func (s *Session) handleCommand(connection ssh.Channel, command string, inSlugEditMode *bool, editSlug *string, commandBuffer *bytes.Buffer) {
switch command {
case "/bye":
connection.Write([]byte("\r\nClosing connection..."))
s.Close()
case "/debug":
log.Println("Client registry:", Clients)
case "/help":
connection.Write([]byte("\r\nAvailable commands: /bye, /help, /clear, /slug"))
case "/clear":
connection.Write([]byte("\033[H\033[2J"))
showWelcomeMessage(s.ConnChannel)
domain := utils.Getenv("domain")
if s.TunnelType == HTTP {
protocol := "http"
if utils.Getenv("tls_enabled") == "true" {
protocol = "https"
}
s.sendMessage(fmt.Sprintf("Forwarding your traffic to %s://%s.%s \r\n", protocol, s.Slug, domain))
} else {
s.sendMessage(fmt.Sprintf("Forwarding your traffic to %s://%s:%d \r\n", s.TunnelType, domain, s.ForwardedPort))
}
case "/slug":
if s.TunnelType != HTTP {
connection.Write([]byte(fmt.Sprintf("\r\n%s tunnels cannot have custom subdomains", s.TunnelType)))
} else {
*inSlugEditMode = true
*editSlug = s.Slug
connection.Write([]byte("\033[H\033[2J"))
displaySlugEditor(connection, s.Slug)
connection.Write([]byte("➤ " + *editSlug + "." + utils.Getenv("domain")))
}
default:
connection.Write([]byte("\r\nUnknown command"))
}
commandBuffer.Reset()
}
func (s *Session) HandleForwardedConnection(conn UserConnection, sshConn *ssh.ServerConn) {
func (s *SSHSession) HandleForwardedConnection(conn UserConnection, sshConn *ssh.ServerConn) {
defer conn.Writer.Close()
log.Printf("Handling new forwarded connection from %s", conn.Writer.RemoteAddr())
@ -553,7 +373,7 @@ func (s *Session) HandleForwardedConnection(conn UserConnection, sshConn *ssh.Se
timestamp := time.Now().Format("02/Jan/2006 15:04:05")
payload := createForwardedTCPIPPayload(host, uint16(originPort), s.ForwardedPort)
payload := createForwardedTCPIPPayload(host, uint16(originPort), s.forwarder.ForwardedPort)
channel, reqs, err := sshConn.OpenChannel("forwarded-tcpip", payload)
if err != nil {
log.Printf("Failed to open forwarded-tcpip channel: %v", err)
@ -606,26 +426,26 @@ func (s *Session) HandleForwardedConnection(conn UserConnection, sshConn *ssh.Se
select {
case err := <-peekChan:
if err == io.EOF {
s.sendMessage(fmt.Sprintf("\033[33m%s -> [%s] WARNING -- \"Could not forward request to the tunnel addr\"\033[0m\r\n", conn.Writer.RemoteAddr().String(), s.TunnelType))
s.interaction.SendMessage(fmt.Sprintf("\033[33m%s -> [%s] WARNING -- \"Could not forward request to the tunnel addr\"\033[0m\r\n", conn.Writer.RemoteAddr().String(), s.forwarder.TunnelType))
sendBadGatewayResponse(conn.Writer)
return
}
if err != nil {
log.Printf("Error peeking channel data: %v", err)
s.sendMessage(fmt.Sprintf("\033[33m%s -> [%s] WARNING -- \"Could not forward request to the tunnel addr\"\033[0m\r\n", conn.Writer.RemoteAddr().String(), s.TunnelType))
s.interaction.SendMessage(fmt.Sprintf("\033[33m%s -> [%s] WARNING -- \"Could not forward request to the tunnel addr\"\033[0m\r\n", conn.Writer.RemoteAddr().String(), s.forwarder.TunnelType))
sendBadGatewayResponse(conn.Writer)
return
}
case <-time.After(5 * time.Second):
log.Printf("Timeout waiting for channel data from %s", conn.Writer.RemoteAddr())
s.sendMessage(fmt.Sprintf("\033[33m%s -> [%s] WARNING -- \"Could not forward request to the tunnel addr\"\033[0m\r\n", conn.Writer.RemoteAddr().String(), s.TunnelType))
s.interaction.SendMessage(fmt.Sprintf("\033[33m%s -> [%s] WARNING -- \"Could not forward request to the tunnel addr\"\033[0m\r\n", conn.Writer.RemoteAddr().String(), s.forwarder.TunnelType))
sendBadGatewayResponse(conn.Writer)
return
case <-ctx.Done():
return
}
s.sendMessage(fmt.Sprintf("\033[32m%s -> [%s] TUNNEL ADDRESS -- \"%s\"\033[0m\r\n", conn.Writer.RemoteAddr().String(), s.TunnelType, timestamp))
s.interaction.SendMessage(fmt.Sprintf("\033[32m%s -> [%s] TUNNEL ADDRESS -- \"%s\"\033[0m\r\n", conn.Writer.RemoteAddr().String(), s.forwarder.TunnelType, timestamp))
_, err = io.Copy(conn.Writer, reader)
if err != nil && !errors.Is(err, io.EOF) {
@ -641,79 +461,6 @@ func sendBadGatewayResponse(writer io.Writer) {
io.Copy(writer, bytes.NewReader([]byte(response)))
}
func showWelcomeMessage(connection ssh.Channel) {
asciiArt := []string{
` _______ _ _____ _ `,
`|__ __| | | | __ \| | `,
` | |_ _ _ __ _ __ ___| | | |__) | |___ `,
` | | | | | '_ \| '_ \ / _ \ | | ___/| / __|`,
` | | |_| | | | | | | | __/ | | | | \__ \`,
` |_|\__,_|_| |_|_| |_|\___|_| |_| |_|___/`,
``,
` "Tunnel Pls" - Project by Bagas`,
` https://fossy.my.id`,
``,
` Welcome to Tunnel! Available commands:`,
` - '/bye' : Exit the tunnel`,
` - '/help' : Show this help message`,
` - '/clear' : Clear the current line`,
` - '/slug' : Set custom subdomain`,
}
for _, line := range asciiArt {
connection.Write([]byte("\r\n" + line))
}
connection.Write([]byte("\r\n\r\n"))
}
func displaySlugEditor(connection ssh.Channel, currentSlug string) {
domain := utils.Getenv("domain")
fullDomain := currentSlug + "." + domain
const paddingRight = 4
contentLine := " ║ Current: " + fullDomain
boxWidth := len(contentLine) + paddingRight + 1
if boxWidth < 50 {
boxWidth = 50
}
topBorder := " ╔" + strings.Repeat("═", boxWidth-4) + "╗\r\n"
title := centerText("SUBDOMAIN EDITOR", boxWidth-4)
header := " ║" + title + "║\r\n"
midBorder := " ╠" + strings.Repeat("═", boxWidth-4) + "╣\r\n"
emptyLine := " ║" + strings.Repeat(" ", boxWidth-4) + "║\r\n"
currentLineContent := fmt.Sprintf(" ║ Current: %s", fullDomain)
currentLine := currentLineContent + strings.Repeat(" ", boxWidth-len(currentLineContent)+1) + "║\r\n"
newLine := " ║ New:" + strings.Repeat(" ", boxWidth-10) + "║\r\n"
saveCancel := " ║ [Enter] Save | [Esc] Cancel" + strings.Repeat(" ", boxWidth-35) + "║\r\n"
bottomBorder := " ╚" + strings.Repeat("═", boxWidth-4) + "╝\r\n"
connection.Write([]byte("\r\n\r\n"))
connection.Write([]byte(topBorder))
connection.Write([]byte(header))
connection.Write([]byte(midBorder))
connection.Write([]byte(emptyLine))
connection.Write([]byte(currentLine))
connection.Write([]byte(emptyLine))
connection.Write([]byte(newLine))
connection.Write([]byte(emptyLine))
connection.Write([]byte(midBorder))
connection.Write([]byte(saveCancel))
connection.Write([]byte(bottomBorder))
connection.Write([]byte("\r\n\r\n"))
}
func centerText(text string, width int) string {
padding := (width - len(text)) / 2
if padding < 0 {
padding = 0
}
return strings.Repeat(" ", padding) + text + strings.Repeat(" ", width-len(text)-padding)
}
func writeSSHString(buffer *bytes.Buffer, str string) {
binary.Write(buffer, binary.BigEndian, uint32(len(str)))
buffer.WriteString(str)