'--------------------------------------------------------------------------------
'This project needs a command button (Command1), and a listview (Listview1).
'--------------------------------------------------------------------------------

Option Explicit

Private Type MIB_TCPROW
dwState As Long
dwLocalAddr As Long
dwLocalPort As Long
dwRemoteAddr As Long
dwRemotePort As Long
End Type

Private Const ERROR_SUCCESS As Long = 0
Private Const MIB_TCP_STATE_CLOSED As Long = 1
Private Const MIB_TCP_STATE_LISTEN As Long = 2
Private Const MIB_TCP_STATE_SYN_SENT As Long = 3
Private Const MIB_TCP_STATE_SYN_RCVD As Long = 4
Private Const MIB_TCP_STATE_ESTAB As Long = 5
Private Const MIB_TCP_STATE_FIN_WAIT1 As Long = 6
Private Const MIB_TCP_STATE_FIN_WAIT2 As Long = 7
Private Const MIB_TCP_STATE_CLOSE_WAIT As Long = 8
Private Const MIB_TCP_STATE_CLOSING As Long = 9
Private Const MIB_TCP_STATE_LAST_ACK As Long = 10
Private Const MIB_TCP_STATE_TIME_WAIT As Long = 11
Private Const MIB_TCP_STATE_DELETE_TCB As Long = 12

Private Declare Function GetTcpTable Lib "iphlpapi.dll" (ByRef pTcpTable As Any, ByRef pdwSize As Long, ByVal bOrder As Long) As Long

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (dst As Any, src As Any, ByVal bcount As Long)

Private Declare Function lstrcpyA Lib "kernel32" (ByVal RetVal As String, ByVal Ptr As Long) As Long

Private Declare Function lstrlenA Lib "kernel32" (ByVal Ptr As Any) As Long

Private Declare Function inet_ntoa Lib "wsock32.dll" (ByVal addr As Long) As Long

Private Declare Function ntohs Lib "wsock32.dll" (ByVal addr As Long) As Long


Public Function GetInetAddrStr(Address As Long) As String

GetInetAddrStr = GetString(inet_ntoa(Address))

End Function


Private Sub Form_Load()

With ListView1
.View = lvwReport
.ColumnHeaders.Add , , "Local IP Address"
.ColumnHeaders.Add , , "Local Port"
.ColumnHeaders.Add , , "Remote IP Address"
.ColumnHeaders.Add , , "Remote Port"
.ColumnHeaders.Add , , "Status "
End With

End Sub


Private Sub ListView1_ColumnClick(ByVal ColumnHeader As ColumnHeader)

ListView1.SortKey = ColumnHeader.Index - 1
ListView1.SortOrder = Abs(Not ListView1.SortOrder = 1)
ListView1.Sorted = True

End Sub


Public Function GetString(ByVal lpszA As Long) As String

GetString = String$(lstrlenA(ByVal lpszA), 0)
Call lstrcpyA(ByVal GetString, ByVal lpszA)

End Function


Private Sub Command1_Click()

Dim TcpRow As MIB_TCPROW
Dim buff() As Byte
Dim lngRequired As Long
Dim lngStrucSize As Long
Dim lngRows As Long
Dim lngCnt As Long
Dim strTmp As String
Dim lstLine As ListItem

Call GetTcpTable(ByVal 0&, lngRequired, 1)

If lngRequired > 0 Then
ReDim buff(0 To lngRequired - 1) As Byte
If GetTcpTable(buff(0), lngRequired, 1) = ERROR_SUCCESS Then
lngStrucSize = LenB(TcpRow)
'first 4 bytes indicate the number of entries
CopyMemory lngRows, buff(0), 4

For lngCnt = 1 To lngRows
'moves past the four bytes obtained above
'to get data and cast into a TcpRow stucture
CopyMemory TcpRow, buff(4 + (lngCnt - 1) * lngStrucSize), lngStrucSize
'sends results to the listview

With TcpRow
Set lstLine = ListView1.ListItems.Add(, , GetInetAddrStr(.dwLocalAddr))
lstLine.SubItems(1) = ntohs(.dwLocalPort)
lstLine.SubItems(2) = GetInetAddrStr(.dwRemoteAddr)
lstLine.SubItems(3) = ntohs(.dwRemotePort)
lstLine.SubItems(4) = (.dwState)
Select Case .dwState
Case MIB_TCP_STATE_CLOSED: strTmp = "closed"
Case MIB_TCP_STATE_LISTEN: strTmp = "listening"
Case MIB_TCP_STATE_SYN_SENT: strTmp = "sent"
Case MIB_TCP_STATE_SYN_RCVD: strTmp = "received"
Case MIB_TCP_STATE_ESTAB: strTmp = "established"
Case MIB_TCP_STATE_FIN_WAIT1: strTmp = "fin wait 1"
Case MIB_TCP_STATE_FIN_WAIT2: strTmp = "fin wait 1"
Case MIB_TCP_STATE_CLOSE_WAIT: strTmp = "close wait"
Case MIB_TCP_STATE_CLOSING: strTmp = "closing"
Case MIB_TCP_STATE_LAST_ACK: strTmp = "last ack"
Case MIB_TCP_STATE_TIME_WAIT: strTmp = "time wait"
Case MIB_TCP_STATE_DELETE_TCB: strTmp = "TCB deleted"
End Select
lstLine.SubItems(4) = lstLine.SubItems(4) & "( " & strTmp & " )"
strTmp = ""
End With

Next

End If
End If

End Sub