InternetModem (modem emulation software) SRC + Binary from BoycoT – backup copy in case his site goes down

'***************************************************
'* This code belongs to Terry R. Olsen
'* You are free to use this code in whole or
'* in part for your own programs. But you may
'* not use this code in any way to create
'* the same type of program for public release.
'* My Email: tolsen64@hotmail.com
'***************************************************
Imports System.Net
Imports System.Net.Sockets
Imports System.Windows.forms
Imports System.Text.ASCIIEncoding
Imports System.IO
Imports System.IO.Ports
Module Module1
 #Region "Telnet Commands"
' Telnet main commands - list copied from somewhere on the net - thank you to them
Const TN_IAC As Int32 = 255 ' Interpret as command escape sequence, Prefix to all telnet commands. 1, 2 or sometimes more commands normally follow this character
Const TN_DONT As Int32 = 254 ' You are not to use this option
Const TN_DO As Int32 = 253 ' Please, you use this option
Const TN_WONT As Int32 = 252 ' I won't use option
Const TN_WILL As Int32 = 251 ' I will use option
Const TN_SB As Int32 = 250 ' Subnegotiate, X number of commands follow
Const TN_GA As Int32 = 249 ' Go ahead
Const TN_EL As Int32 = 248 ' Erase line
Const TN_EC As Int32 = 247 ' Erase character
Const TN_AYT As Int32 = 246 ' Are you there
Const TN_AO As Int32 = 245 ' Abort output
Const TN_IP As Int32 = 244 ' Interrupt process
Const TN_BRK As Int32 = 243 ' BreakInternetModem
Const TN_DM As Int32 = 242 ' Data mark
Const TN_NOP As Int32 = 241 ' No operation.
Const TN_SE As Int32 = 240 ' End of subnegotiation, from above
Const TN_EOR As Int32 = 239 ' End of record
Const TN_ABORT As Int32 = 238 ' About process
Const TN_SUSP As Int32 = 237 ' Suspend process
Const TO_EOF As Int32 = 236 ' End of file
' Telnet (option) mainly return commands from above
Const TN_BIN As Int32 = 0 ' Binary transmission
Const TN_ECHO As Int32 = 1 ' Echo
Const TN_RECN As Int32 = 2 ' Reconnection
Const TN_SUPP As Int32 = 3 ' Suppress go ahead
Const TN_APRX As Int32 = 4 ' Approx message size negotiation
Const TN_STAT As Int32 = 5 ' Status
Const TN_TIM As Int32 = 6 ' Timing mark
Const TN_REM As Int32 = 7 ' Remote controlled trans/echo
Const TN_OLW As Int32 = 8 ' Output line width
Const TN_OPS As Int32 = 9 ' Output page size
Const TN_OCRD As Int32 = 10 ' Out carriage-return disposition
Const TN_OHT As Int32 = 11 ' Output horizontal tabstops
Const TN_OHTD As Int32 = 12 ' Out horizontal tab disposition
Const TN_OFD As Int32 = 13 ' Output formfeed disposition
Const TN_OVT As Int32 = 14 ' Output vertical tabstops
Const TN_OVTD As Int32 = 15 ' Output vertical tab disposition
Const TN_OLD As Int32 = 16 ' Output linefeed disposition
Const TN_EXT As Int32 = 17 ' Extended ascii character set
Const TN_LOGO As Int32 = 18 ' Logout
Const TN_BYTE As Int32 = 19 ' Byte macro
Const TN_DATA As Int32 = 20 ' Data entry terminal
Const TN_SUP As Int32 = 21 ' supdup protocol
Const TN_SUPO As Int32 = 22 ' supdup output
Const TN_SNDL As Int32 = 23 ' Send location
Const TN_TERM As Int32 = 24 ' Terminal type
Const TO_EOR As Int32 = 25 ' End of record
Const TN_TACACS As Int32 = 26 ' Tacacs user identification
Const TN_OM As Int32 = 27 ' Output marking
Const TN_TLN As Int32 = 28 ' Terminal location number
Const TN_3270 As Int32 = 29 ' Telnet 3270 regime
Const TN_X3 As Int32 = 30 ' X.3 PAD
Const TN_NAWS As Int32 = 31 ' Negotiate about window size
Const TN_TS As Int32 = 32 ' Terminal speed
Const TN_RFC As Int32 = 33 ' Remote flow control
Const TN_LINE As Int32 = 34 ' Linemode
Const TN_XDL As Int32 = 35 ' X display location
Const TN_ENVIR As Int32 = 36 ' Telnet environment option
Const TN_AUTH As Int32 = 37 ' Telnet authentication option
Const TN_NENVIR As Int32 = 39 ' Telnet environment option
Const TN_EXTOP As Int32 = 25 ' Extended-options-list
 #End Region
'Serial Port Stuff
Dim WithEvents Ser As New SerialPort
'Telnet Stuff
Dim LineSize As Integer
Dim TcpPort As Integer = 23
Dim TcpSvr As Socket 'TCP Listener Socket, listens for incoming calls
Dim TcpClt As Socket 'TCP Client Socket, handles incoming calls
Dim TcpMsg As Socket 'Tells Clients that we're busy right now...
'Send & Receive Buffers
Dim RcvBuf() As Byte 'In from TCP/Out to Serial
Dim XmtBuf() As Byte 'In from Serial/Out to TCP
Dim SerByt As Integer 'Bytes to read from serial port
Dim Throttle As Integer 'Some slower terminals may need to slow it down
'BBS not available message
Dim msg() As Byte = ASCII.GetBytes("The line is busy. Please try again later.")
'Stopwatch for measuring +++ Guard Time
Dim swGuardTimer As New System.Timers.Timer
'Application variables
Dim logFile As String
Dim iniFile As String
Dim keepLog As Boolean = False
Dim ver As String = "6.7.29.1"
'Modem Emulator Stuff
Enum ModemEcho
EchoOff = 0
EchoOn = 1
End Enum
Enum ModemResultCodeFormat
Numeric = 0
Text = 1
End Enum
Enum ModemResultCodes
Enabled = 0
Disabled = 1
End Enum
Enum ModemRingMode
SendRing = 0
SendConnect = 1
End Enum
Enum ModemHookState
OnHook = 0
OffHook = 1
End Enum
Const OK As Integer = 0
Const CONNECT As Integer = 1
Const RING As Integer = 2
Const NO_CARRIER As Integer = 3
Const ERR As Integer = 4
Const NO_DIAL_TONE As Integer = 6
Const BUSY As Integer = 7
Const NO_ANSWER As Integer = 8
Dim MdmErr As Integer
Dim MdmErrorCode() As String = {"OK", "CONNECT", "RING", "NO CARRIER", "ERROR", "", "NO DIAL TONE", "BUSY", "NO ANSWER"}
Dim MdmCmdMode As Boolean = True 'Are we in command mode?
Dim MdmCmdStr As String
Dim MdmResultCodeFormat As ModemResultCodeFormat = ModemResultCodeFormat.Numeric
Dim MdmEcho As ModemEcho = ModemEcho.EchoOn
Dim MdmResultCodes As ModemResultCodes = ModemResultCodes.Enabled
Dim MdmRingMode As ModemRingMode = ModemRingMode.SendConnect
Dim MdmHookState As ModemHookState = ModemHookState.OnHook
Dim MdmBaud As String
Sub Main()
'Display Program & Author Information
Console.WriteLine("Internet Modem v" & ver & " by Terry R. Olsen")
Console.WriteLine("Call The BoycoT BBS: telnet://boycot.no-ip.com:9999")
Console.WriteLine("Get the latest version of this program: http://boycot.no-ip.com/InternetModem")
Console.WriteLine("Email: tolsen64@hotmail.com")
Console.WriteLine("=============================================================================")
'Load the INI file. This defines our variables.
WriteStatus("Loading Initialization Data")
Dim tmpPth As String = My.Application.Info.DirectoryPath
If Right(tmpPth, 1) <> "\" Then tmpPth += "\"
iniFile = tmpPth + "InternetModem.ini"
logFile = tmpPth + "InternetModem.log"
Dim r As New StreamReader(iniFile)
Dim tmp() As String
While r.Peek > 0
tmp = Split(r.ReadLine, "=")
Select Case tmp(0)
Case "TcpPort"
TcpPort = CInt(tmp(1))
Case "SerPort"
Ser.PortName = "COM" & Trim(tmp(1))
Case "SerBaud"
Ser.BaudRate = CInt(tmp(1))
MdmBaud = Trim(tmp(1))
Case "SerDataBits"
Ser.DataBits = CInt(tmp(1))
Case "SerParity"
If tmp(1) = "None" Then Ser.Parity = Parity.None
If tmp(1) = "Odd" Then Ser.Parity = Parity.Odd
If tmp(1) = "Even" Then Ser.Parity = Parity.Even
If tmp(1) = "Mark" Then Ser.Parity = Parity.Mark
If tmp(1) = "Space" Then Ser.Parity = Parity.Space
Case "SerStopBits"
If tmp(1) = 1 Then Ser.StopBits = StopBits.One
If tmp(1) = 1.5 Then Ser.StopBits = StopBits.OnePointFive
If tmp(1) = 2 Then Ser.StopBits = StopBits.Two
Case "Handshake"
If tmp(1) = "None" Then Ser.Handshake = Handshake.None
If tmp(1) = "RTS" Then Ser.Handshake = Handshake.RequestToSend
If tmp(1) = "RTS/XonXoff" Then Ser.Handshake = Handshake.RequestToSendXOnXOff
If tmp(1) = "XonXoff" Then Ser.Handshake = Handshake.XOnXOff
Case "RcvBuf"
Ser.WriteBufferSize = CInt(tmp(1))
ReDim RcvBuf(CInt(tmp(1)))
Case "XmtBuf"
Ser.ReadBufferSize = CInt(tmp(1))
ReDim XmtBuf(CInt(tmp(1)))
Case "KeepLog"
keepLog = CBool(tmp(1))
Case "BBSName"
msg = ASCII.GetBytes(tmp(1) & " is currently in use." & vbCrLf & vbCrLf & _
"Please try again soon!" & vbCrLf & vbCrLf & _
"While you're waiting...give The BoycoT BBS a call..." & vbCrLf & _
"telnet://boycot.no-ip.com:9999")
Case "Throttle"
Throttle = CInt(tmp(1))
Case "LineSize"
LineSize = CInt(tmp(1))
End Select
End While
r.Close()
Ser.ReceivedBytesThreshold = 1 'Raise an event for each character received
'Open the serial port
WriteStatus("Opening " & Ser.PortName & "," & Ser.BaudRate & "," & Ser.DataBits & _
"," & Ser.Parity.ToString & "," & Ser.StopBits & "," & Ser.Handshake.ToString)
Try
Ser.Open()
Ser.DtrEnable = True
Ser.RtsEnable = True
Catch ex As Exception
WriteStatus(ex.Message)
WriteStatus("Failed!")
Console.WriteLine("Press ENTER to exit.")
Console.ReadLine()
Exit Sub
End Try
StartTCPServer()
AddHandler swGuardTimer.Elapsed, AddressOf swGuardTimerFired
swGuardTimer.Interval = 1000
'swGuardTimer.Enabled = True
swGuardTimer.Stop()
Application.Run() 'Keeps us running...
End Sub
'====================================================================
'Our TCP Server Routines.
Private Sub StartTCPServer()
Dim addr As IPAddress = IPAddress.Parse("0.0.0.0")
Dim ep As New IPEndPoint(addr, TcpPort)
TcpSvr = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
TcpSvr.Bind(ep)
TcpSvr.Listen(2)
TcpSvr.BeginAccept(AddressOf AcceptCallback, TcpSvr)
WriteStatus("Listening for calls on TCP Port " & TcpPort)
End Sub
Private Sub AcceptCallback(ByVal ar As IAsyncResult)
System.Threading.Thread.CurrentThread.Name = "AcceptCallback"
Debug.WriteLine(Now.ToLongTimeString & " AcceptCallback")
If TcpClt Is Nothing And MdmHookState = ModemHookState.OnHook Then
Debug.WriteLine("TcpClt=Nothing, MdmHookState=" & MdmHookState.ToString)
TcpClt = TcpSvr.EndAccept(ar)
WriteStatus("Connected to " & CType(TcpClt.RemoteEndPoint, IPEndPoint).ToString)
TcpClt.BeginReceive(RcvBuf, 0, RcvBuf.Length, SocketFlags.None, AddressOf ReceiveCallback, RcvBuf)
MdmCmdMode = False
MdmHookState = ModemHookState.OffHook
ModemError(1)
Else
Debug.WriteLine(Now.ToLongTimeString & " TcpMsg started")
TcpMsg = TcpSvr.EndAccept(ar)
TcpMsg.Send(msg)
WriteStatus("Sent busy message to " & CType(TcpMsg.RemoteEndPoint, IPEndPoint).ToString)
TcpMsg.Shutdown(SocketShutdown.Both)
TcpMsg.Close()
TcpMsg = Nothing
End If
TcpSvr.BeginAccept(AddressOf AcceptCallback, TcpSvr)
WriteStatus("Listening for calls on TCP Port " & TcpPort)
End Sub
Private Sub ReceiveCallback(ByVal ar As IAsyncResult)
System.Threading.Thread.CurrentThread.Name = "ReceiveCallback"
RcvBuf = CType(ar.AsyncState, Byte())
Dim numbytes As Int32
Try
numbytes = TcpClt.EndReceive(ar)
Catch
Exit Sub
End Try
If numbytes = 0 Then 'client has disconnected.
Ser.DtrEnable = False
Ser.RtsEnable = False
HangUp(False) 'False = Remote initiated disconnect
MdmHookState = ModemHookState.OnHook
Ser.DtrEnable = True
Ser.RtsEnable = True
ModemError(NO_CARRIER)
Exit Sub
End If
If MdmCmdMode = False Then ProcessIncoming(numbytes)
TcpClt.BeginReceive(RcvBuf, 0, RcvBuf.Length, SocketFlags.None, AddressOf ReceiveCallback, RcvBuf)
End Sub
Sub ProcessIncoming(ByVal numbytes As Int32)
For i As Integer = 0 To numbytes - 1
Select Case RcvBuf(i)
Case TN_IAC
'WriteStatus("Telnet Protocol in use.")
Dim byt(0 To 2) As Byte
byt(0) = TN_IAC
i += 1
Select Case RcvBuf(i)
Case TN_SB
'ToChatWindow(" TN_SB" & vbCrLf)
WriteStatus("TN_SB Received! Subnegotiate Incomplete.")
Do
i += 1
Loop Until RcvBuf(i) = TN_SE Or i = numbytes - 1
Case TN_DO 'Server asking you to do something
'ToChatWindow(" TN_DO " & Str(buffer(i + 1)) & vbCrLf)
i += 1
Select Case RcvBuf(i)
Case TN_NAWS
byt(1) = TN_WILL
byt(2) = RcvBuf(i)
SendBytesToHost(byt)
SetLineSize()
Case Else
byt(1) = TN_WONT
byt(2) = RcvBuf(i)
SendBytesToHost(byt)
End Select
Case TN_DONT 'Server asking you to NOT do something
'ToChatWindow(" TN_DONT" & Str(buffer(i + 1)) & vbCrLf)
byt(1) = TN_WONT
i += 1
byt(2) = RcvBuf(i)
SendBytesToHost(byt)
Case TN_WILL 'Server telling you it will do something
'ToChatWindow(" TN_WILL" & Str(buffer(i + 1)) & vbCrLf)
byt(1) = TN_DONT
i += 1
byt(2) = RcvBuf(i)
SendBytesToHost(byt)
Case TN_WONT 'Server telling you it won't do someting
'ToChatWindow(" TN_WONT" & Str(buffer(i + 1)) & vbCrLf)
byt(1) = TN_DONT
i += 1
byt(2) = RcvBuf(i)
SendBytesToHost(byt)
End Select
Case Else
Try
Threading.Thread.Sleep(Throttle)
'Debug.Write(ASCII.GetString(RcvBuf, i, 1))
Ser.Write(RcvBuf, i, 1)
Catch ex As Exception
WriteStatus("----------------------------")
WriteStatus("Routine: ReceiveCallBack")
WriteStatus("Exception: " & ex.Message)
WriteStatus("Chat Msg: " & Chr(RcvBuf(i)))
End Try
End Select
Next
End Sub
Private Sub SetLineSize()
'The syntax for the subnegotiation is: IAC SB NAWS WIDTH[1] WIDTH[0] HEIGHT[1] HEIGHT[0] IAC SE
Dim byt() As Byte = {TN_IAC, TN_SB, TN_NAWS, LineSize \ 256, LineSize Mod 256, 0, 24, TN_IAC, TN_SE}
SendBytesToHost(byt)
End Sub
Private Sub SendBytesToHost(ByVal byt() As Byte)
TcpClt.Send(byt, byt.Length, SocketFlags.None)
End Sub
Private Sub HangUp(ByVal local As Boolean)
MdmErr = OK
If Not TcpClt Is Nothing Then
Try
TcpClt.Shutdown(SocketShutdown.Both)
TcpClt.Close()
TcpClt = Nothing
MdmErr = NO_CARRIER
If local = True Then
WriteStatus("Locally initiated disconnect")
Else
WriteStatus("Remote initiated disconnect")
End If
Catch ex As Exception
WriteStatus("Locally initiated disconnect, already offline")
End Try
Else
WriteStatus("Locally initiated disconnect, already offline")
End If
MdmCmdMode = True
Debug.WriteLine(MdmCmdMode.ToString)
End Sub
'Routine to write status to console window...
'and to log file if set.
Private Sub WriteStatus(ByVal msg As String)
Dim dt As String = Date.Now.ToShortDateString & " " & Date.Now.ToShortTimeString
msg = dt & " - " & msg
Console.WriteLine(msg)
Exit Sub
If keepLog = True Then
Dim sw As New StreamWriter(logFile, True)
'w = My.Computer.FileSystem.OpenTextFileWriter(logFile, True)
sw.WriteLine(msg)
sw.Close()
End If
End Sub
Private Sub SerRcvEvent(ByVal sender As Object, ByVal e As SerialDataReceivedEventArgs) Handles Ser.DataReceived
SerByt = Ser.BytesToRead
Ser.Read(XmtBuf, 0, SerByt)
Dim rcvString As String = ASCII.GetString(XmtBuf, 0, SerByt)
Debug.Write(rcvString)
' --Did we get a Modem Esc Command?
' If so, start the 1 second timer.
If InStr(rcvString, "+++") Then
swGuardTimer.Start()
End If
' --If we're in command mode, send characters received to be processed
If MdmCmdMode = True Then
ProcessMdmCmd(rcvString)
Exit Sub
End If
' --Otherwise, send it out to our connected user.
If TcpClt Is Nothing Then Exit Sub
Try
TcpClt.Send(XmtBuf, SerByt, SocketFlags.None)
Catch
End Try
End Sub
Private Sub ProcessMdmCmd(ByVal CmdStr As String)
MdmErr = OK
MdmCmdStr += UCase(CmdStr)
If MdmEcho = ModemEcho.EchoOn Then Ser.Write(CmdStr)
'--Command is still coming in if we haven't received the CR
If Right(MdmCmdStr, 1) <> Chr(13) Then Exit Sub
'--CR only does not a command make...
If MdmCmdStr.Equals(vbCr) Then
MdmCmdStr = ""
Exit Sub
End If
'--Get rid of the +'s from the ESC sequence, and trim off the CR
MdmCmdStr = MdmCmdStr.Replace("+", "").Trim(Chr(13))
Debug.WriteLine("MdmCmdStr: " & MdmCmdStr)
'--All good command strings begin with AT
If Left(MdmCmdStr, 2) <> "AT" Then
Debug.WriteLine("MdmCmdStr doesn't begin with AT")
MdmCmdStr = ""
ModemError(ERR)
Exit Sub
End If
'--Sometimes they just type AT to see if the modem is responding.
If MdmCmdStr = "AT" Then
MdmCmdStr = ""
ModemError(OK)
Exit Sub
End If
'--Now start dealing with the command strings...
Dim tmpCmd As String
If InStr(MdmCmdStr, "ATA") Then
MdmCmdStr = ""
End If
If InStr(MdmCmdStr, "ATD ") Or InStr(MdmCmdStr, "ATDT ") Then
GoDialOut(MdmCmdStr)
MdmCmdStr = ""
Exit Sub
End If
If InStr(MdmCmdStr, "ATI") Then
Ser.Write("Internet Modem Emulator v" & ver & " by Terry Olsen" & vbCr)
MdmErr = OK
MdmCmdStr = ""
'Exit Sub
End If
If InStr(MdmCmdStr, "AT&V") Then
Ser.Write("This will be our &V display page." & vbCr)
MdmErr = OK
MdmCmdStr = ""
'Exit Sub
End If
If InStr(MdmCmdStr, "ATZ") Then
HangUp(True)
MdmCmdMode = True
MdmHookState = ModemHookState.OnHook
MdmCmdStr = ""
End If
If InStr(MdmCmdStr, "E") Then
tmpCmd = Mid(MdmCmdStr, InStr(MdmCmdStr, "E") + 1, 1)
Debug.Write("E" & tmpCmd & ":")
If Val(tmpCmd) > 1 Then
MdmErr = ERR
Else
MdmEcho = Val(tmpCmd)
End If
MdmCmdStr = ""
End If
If InStr(MdmCmdStr, "H") Then
tmpCmd = Mid(MdmCmdStr, InStr(MdmCmdStr, "H") + 1, 1)
Debug.Write("H" & tmpCmd & ":")
If Val(tmpCmd) > 1 Then
MdmErr = ERR
Else
MdmHookState = Val(tmpCmd)
HangUp(True) 'True = Locally initiated disconnect
End If
MdmCmdStr = ""
End If
If InStr(MdmCmdStr, "Q") Then
tmpCmd = Mid(MdmCmdStr, InStr(MdmCmdStr, "Q") + 1, 1)
Debug.Write("Q" & tmpCmd & ":")
If Val(tmpCmd) > 1 Then
MdmErr = ERR
Else
MdmEcho = Val(tmpCmd)
End If
MdmCmdStr = ""
End If
If InStr(MdmCmdStr, "S0") Then
tmpCmd = Mid(MdmCmdStr, InStr(MdmCmdStr, "S0=") + 3, 1)
Debug.Write("S0=" & tmpCmd & ":")
If Val(tmpCmd) > 1 Then
MdmErr = ERR
Else
MdmRingMode = Val(tmpCmd)
End If
MdmCmdStr = ""
End If
If InStr(MdmCmdStr, "V") Then
tmpCmd = Mid(MdmCmdStr, InStr(MdmCmdStr, "V") + 1, 1)
Debug.Write("V" & tmpCmd & ":")
If Val(tmpCmd) > 1 Then
MdmErr = ERR
Else
MdmResultCodeFormat = Val(tmpCmd)
End If
MdmCmdStr = ""
End If
ModemError(MdmErr)
End Sub
Private Sub ModemError(ByVal code As Integer)
If MdmResultCodes = ModemResultCodes.Enabled Then
If MdmResultCodeFormat = ModemResultCodeFormat.Text Then
Debug.WriteLine("MdmErrCode: " & MdmErrorCode(code))
Ser.Write(vbCr & MdmErrorCode(code))
If code = 1 Then Ser.Write(" " & MdmBaud)
Ser.Write(vbCr)
Else
Ser.Write(vbCr & code & vbCr)
Debug.WriteLine("MdmErrCode: " & code)
End If
End If
End Sub
Private Sub GoDialOut(ByVal cmd As String)
Dim port As Integer
Dim IP As IPAddress
Dim host As String
'--First, get rid of the AT command
cmd = cmd.Replace("ATDT ", "").Trim
cmd = cmd.Replace("ATD ", "").Trim
cmd = cmd.Trim(Chr(13))
'Debug.WriteLine("CMD=" & cmd)
'--Next, see if a port is specified
cmd = cmd.Replace(",", ":") 'Change comma separator to colon
cmd = cmd.Replace(" ", ":") 'change space separator to colon
'Debug.WriteLine("CMD=" & cmd)
'--Define the port we'll use to dial out
If cmd.Contains(":") Then
port = Val(Mid(cmd, InStr(cmd, ":") + 1))
cmd = cmd.Remove(cmd.IndexOf(":"))
Else
port = 23
End If
'Debug.WriteLine("CMD=" & cmd)
'Debug.WriteLine("PORT=" & port)
'Exit Sub
'--Now we check what kind of address we have. It could be:
' hostname.com, xx.xxx.xx.x, or WWWXXXYYYZZZ
Dim IpNoDots As Boolean = True
If Not cmd.Contains(".") Then
If cmd.Length = 12 Then
For i As Integer = 1 To 12
If Not (Mid(cmd, i, 1) >= "0" And Mid(cmd, i, 1) <= "9") Then
IpNoDots = False : Exit For
End If
Next
If IpNoDots = True Then
cmd = cmd.Insert(9, ".")
cmd = cmd.Insert(6, ".")
cmd = cmd.Insert(3, ".")
End If
End If
End If
'Debug.WriteLine("CMD=" & cmd)
'Debug.WriteLine("PORT=" & port)
'Exit Sub
'--By the time we get here, we should have either a hostname or
' an IP address in the form of xxx.xx.xx.x
Try
IP = Dns.GetHostEntry(cmd).AddressList(0)
Try
host = Dns.GetHostEntry(IP).HostName
Catch
host = cmd
End Try
WriteStatus("Dialing: " & host & " (" & IP.ToString & ") on port " & port.ToString)
Catch ex As SocketException
WriteStatus("Error dialing " & cmd & ":" & port.ToString)
WriteStatus("Error message:" & ex.Message)
ModemError(NO_DIAL_TONE)
Exit Sub
End Try
MdmCmdMode = False
Dim IPE As New IPEndPoint(IP, port)
Try
TcpClt = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
TcpClt.BeginConnect(IPE, AddressOf DialOutConnected, Nothing)
Catch ex As SocketException
ModemError(NO_DIAL_TONE)
WriteStatus(ex.Message)
End Try
End Sub
Private Sub DialOutConnected(ByVal ar As IAsyncResult)
Try
TcpClt.EndConnect(ar)
Catch ex As SocketException
WriteStatus(ex.Message)
MdmCmdMode = True
ModemError(NO_ANSWER)
Exit Sub
End Try
WriteStatus("Connection established.")
ModemError(CONNECT)
TcpClt.BeginReceive(RcvBuf, 0, RcvBuf.Length, SocketFlags.None, AddressOf ReceiveCallback, RcvBuf)
End Sub
Private Sub swGuardTimerFired(ByVal sender As Object, ByVal e As System.Timers.ElapsedEventArgs)
swGuardTimer.Stop()
If Ser.BytesToRead < 1 Then
MdmCmdMode = True
ModemError(OK)
Else
MdmCmdMode = False
If TcpClt Is Nothing Then Exit Sub
TcpClt.Send(XmtBuf, SerByt, SocketFlags.None)
End If
End Sub
End Module

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