clstcpprotocol.cls

入侵检测是近几年发展起来的新型网络安全策略

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
  Persistable = 0  'NotPersistable
  DataBindingBehavior = 0  'vbNone
  DataSourceBehavior  = 0  'vbNone
  MTSTransactionMode  = 0  'NotAnMTSObject
END
Attribute VB_Name = "clsTCPProtocol"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
'****************************************************************************
'人人为我，我为人人
'枕善居汉化收藏整理
'发布日期：2006/12/23
'描    述：非常专业的防火墙源代码
'网    站：http://www.Mndsoft.com/  (VB6源码博客)
'网    站：http://www.VbDnet.com/   (VB.NET源码博客,主要基于.NET2005)
'e-mail  ：[e-mail]
'e-mail  ：[e-mail]
'OICQ    ：88382850
'          如果您有新的好的代码别忘记给枕善居哦!
'****************************************************************************
Option Explicit
Private Type TCPHeader
    src_portno                      As Integer
    dst_portno                      As Integer
    Sequenceno                      As Long
    Acknowledgeno                   As Long
    DataOffset                      As Byte
    flag                            As Byte
    Windows                         As Integer
    Checksum                        As Integer
    UrgentPointer                   As Integer
End Type
Public Enum TCPFlag
    TCPF_FIN = 1
    TCPF_SYN = 2
    TCPF_RST = 4
    TCPF_PSH = 8
    TCPF_ACK = 16
    TCPF_URG = 32
End Enum
Private m_src_portno                As Integer
Private m_dst_portno                As Integer
Private m_Sequenceno                As Double
Private m_Acknowledgeno             As Double
Private m_DataOffset                As Byte
Private m_flag                      As Byte
Private m_Windows                   As Integer
Private m_checksum                  As Long
Private m_UrgentPointer             As Integer
Public ProtocolInterface        As clsProtocolInterface
Public Event RecievedPacket(IPHeader As clsIPHeader, TCPProtocol As clsTCPProtocol, Data As String, bData() As Byte)
Public Sub PacketArrived(IPH As clsIPHeader, ReadBuffer() As Byte, BytesRecieved As Long)
    Dim TCPH                        As TCPHeader
    Dim DataOffset                  As Integer
    Dim PayloadSize                 As Long
    Dim bPayload()                  As Byte
    Dim strPayload                  As String
    CopyMemory TCPH, ByVal VarPtr(ReadBuffer(0)) + 20, LenB(TCPH)
    DataOffset = 20 + (TCPH.DataOffset \ &H10) * 4
    PayloadSize = BytesRecieved - DataOffset
    If PayloadSize > 0 Then
        ReDim bPayload(0 To PayloadSize - 1)
        CopyMemory ByVal VarPtr(bPayload(0)), ByVal VarPtr(ReadBuffer(DataOffset)), PayloadSize
        strPayload = StrConv(bPayload, vbUnicode)
    End If
    AckNumber = LongToUnsigned(ntohl(TCPH.Acknowledgeno))
    Checksum = IntegerToUnsigned(ntohs(TCPH.Checksum))
    DataOffset = DataOffset
    DestPort = ntohs(TCPH.dst_portno)
    Flags = TCPH.flag
    SequenceNumber = LongToUnsigned(ntohl(TCPH.Sequenceno))
    SourcePort = ntohs(TCPH.src_portno)
    UrgentPointer = ntohs(TCPH.UrgentPointer)
    Windows = ntohs(TCPH.Windows)
    RaiseEvent RecievedPacket(IPH, Me, strPayload, bPayload)
End Sub
Public Sub SendPacket(strDestination As String, DestPort As Long, IPHeader As clsIPHeader, Data As String)
    Dim IPH                         As IPHeader
    Dim TCPH                        As TCPHeader
    Dim Packet()                    As Byte
    Dim bData()                     As Byte
    With IPH
        .ip_checksum = htons(UnsignedToInteger(IPHeader.Checksum))
        .ip_destaddr = IPHeader.DestAddress
        .ip_id = htons(UnsignedToInteger(IPHeader.ID))
        .ip_offset = htons(IPHeader.Offset)
        .ip_protocol = IPHeader.Protocol
        .ip_srcaddr = IPHeader.SourceAddress
        .ip_tos = IPHeader.TypeOfService
        .ip_totallength = htons(IPHeader.Checksum)
        .ip_ttl = IPHeader.TypeOfService
        .ip_verlen = MakeByte(IPHeader.HeaderLength, IPHeader.Version)
    End With
    With TCPH
        .Acknowledgeno = htonl(UnsignedToLong(AckNumber))
        .Checksum = htons(UnsignedToInteger(Checksum))
        .DataOffset = DataOffset
        .dst_portno = htons(DestPort)
        .flag = Flags
        .Sequenceno = htonl(UnsignedToLong(SequenceNumber))
        .src_portno = htons(SourcePort)
        .UrgentPointer = htons(UrgentPointer)
        .Windows = htons(Windows)
    End With
    bData = StrConv(Data, vbFromUnicode)
    ReDim Packet(LenB(IPH) + LenB(TCPH) + UBound(bData))
    CopyMemory ByVal VarPtr(Packet(0)), ByVal VarPtr(IPH), LenB(IPH)
    CopyMemory ByVal VarPtr(Packet(0)) + LenB(IPH), ByVal VarPtr(TCPH), LenB(TCPH)
    CopyMemory ByVal VarPtr(Packet(0)) + LenB(IPH) + LenB(TCPH), ByVal VarPtr(bData(0)), UBound(bData) + 1
    ProtocolInterface.SendData strDestination, DestPort, Packet
End Sub
Public Property Get SourcePort() As ServicePort
    SourcePort = m_src_portno
End Property
Public Property Let SourcePort(val As ServicePort)
    m_src_portno = val
End Property
Public Property Get DestPort() As ServicePort
    DestPort = m_dst_portno
End Property
Public Property Let DestPort(val As ServicePort)
    m_dst_portno = val
End Property
Public Property Get SequenceNumber() As Double
    SequenceNumber = m_Sequenceno
End Property
Public Property Let SequenceNumber(val As Double)
    m_Sequenceno = val
End Property
Public Property Get AckNumber() As Double
    AckNumber = m_Acknowledgeno
End Property
Public Property Let AckNumber(val As Double)
    m_Acknowledgeno = val
End Property
Public Property Get DataOffset() As Byte
    DataOffset = m_DataOffset
End Property
Public Property Let DataOffset(val As Byte)
    m_DataOffset = val
End Property
Public Property Get Flags() As Byte
    Flags = m_flag
End Property
Public Property Let Flags(val As Byte)
    m_flag = val
End Property
Public Property Get Windows() As Integer
    Windows = m_Windows
End Property
Public Property Let Windows(val As Integer)
    m_Windows = val
End Property
Public Property Get Checksum() As Long
    Checksum = m_checksum
End Property
Public Property Let Checksum(val As Long)
    m_checksum = val
End Property
Public Property Get UrgentPointer() As Integer
    UrgentPointer = m_UrgentPointer
End Property
Public Property Let UrgentPointer(val As Integer)
    m_UrgentPointer = val
End Property
Public Function IsFlagSet(aFlag As TCPFlag) As Boolean
    IsFlagSet = m_flag And aFlag
End Function
Public Function GetTCPFlagStr() As String
    GetTCPFlagStr = GetTCPFlagStr & IIf(m_flag And TCPF_URG, "U", "x")      ' URG
    GetTCPFlagStr = GetTCPFlagStr & IIf(m_flag And TCPF_ACK, "A", "x")      ' ACK
    GetTCPFlagStr = GetTCPFlagStr & IIf(m_flag And TCPF_PSH, "P", "x")      ' PSH
    GetTCPFlagStr = GetTCPFlagStr & IIf(m_flag And TCPF_RST, "R", "x")      ' RST
    GetTCPFlagStr = GetTCPFlagStr & IIf(m_flag And TCPF_SYN, "S", "x")      ' SYN
    GetTCPFlagStr = GetTCPFlagStr & IIf(m_flag And TCPF_FIN, "F", "x")      ' FIN
End Function