Serwer Websocket VB.NET - ramka danych
Próbuję stworzyć najprostszy serwer WebSocket za pomocą VB.NET. Udaje mi się zaimplementować uzgadnianie, ale nie mogę wysłać wiadomości po uzgadnianiu. Oto mój kod:
Dim serverTcp As TcpListener
Dim serverThread As Thread
Sub Main()
'' Start server
serverThread = New Thread(AddressOf serverProc)
serverThread.Start()
End Sub
Private Sub serverProc()
'' Listen to port 8181
serverTcp = New TcpListener(8181)
serverTcp.Start()
Console.WriteLine("Listen to port 8181 ...")
'' Accept any connection
While (True)
Dim curSocket As Socket = serverTcp.AcceptSocket()
Dim thread As New Thread(AddressOf clientProc)
thread.Start(curSocket)
End While
End Sub
Private Sub clientProc(ByVal sck As Socket)
Dim netStream As New NetworkStream(sck)
Dim netReader As New IO.StreamReader(netStream)
Dim netWriter As New IO.StreamWriter(netStream)
Dim key As String = ""
Console.WriteLine("Accept new connection ...")
'' Reading handshake message
While (True)
Dim line As String = netReader.ReadLine()
If line.Length = 0 Then
Exit While
End If
If (line.StartsWith("Sec-WebSocket-Key: ")) Then
key = line.Split(":")(1).Trim()
End If
Console.WriteLine("Data: " & line)
End While
'' Calculate accept-key
key += "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
key = getSHA1Hash(key)
'' Response handshake message
Dim response As String
response = "HTTP/1.1 101 Switching Protocols" & vbCrLf
response &= "Upgrade: websocket" & vbCrLf
response &= "Connection: Upgrade" & vbCrLf
response &= "Sec-WebSocket-Accept: " & key & vbCrLf & vbCrLf
netWriter.Write(response)
netWriter.Flush()
'' Sending Hello World message
Dim message As String = "Hello World"
Dim messageByte() As Byte = System.Text.Encoding.UTF8.GetBytes(message)
Dim startByte() As Byte = {&H0}
Dim endByte() As Byte = {&HFF}
sck.Send(startByte, 1, 0)
sck.Send(messageByte)
sck.Send(endByte, 1, 0)
End Sub
Function getSHA1Hash(ByVal strToHash As String) As String
Dim sha1Obj As New Security.Cryptography.SHA1CryptoServiceProvider
Dim bytesToHash() As Byte = System.Text.Encoding.ASCII.GetBytes(strToHash)
Dim result As String
bytesToHash = sha1Obj.ComputeHash(bytesToHash)
result = Convert.ToBase64String(bytesToHash)
Return result
End Function
Standard mówi, że muszę wysłać0x00
bajt, po bajcie UTF8 i kończymy na0xFF
bajt. Zrobiłem tak, jak powiedziałem, ale mój klient HTML nie może odebrać wiadomości.
Oto mój kod HTML5:
<script>
if('WebSocket' in window){
connect('ws://localhost:8181/service');
}
function connect(host) {
var ws = new WebSocket(host);
ws.onopen = function () {
alert('connected');
};
ws.onmessage = function (evt) {
alert('reveived data:'+evt.data);
};
ws.onclose = function () {
alert('socket closed');
};
};
</script>