clsudpprotocol.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 = "clsUDPProtocol"
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 UDPHeader
    src_portno                  As Integer
    dst_portno                  As Integer
    udp_length                  As Integer
    udp_checksum                As Integer
End Type
Private m_src_portno            As Integer
Private m_dst_portno            As Integer
Private m_udp_length            As Integer
Private m_udp_checksum          As Long
Public ProtocolInterface        As clsProtocolInterface
Public Event RecievedPacket(IPHeader As clsIPHeader, UDPProtocol As clsUDPProtocol, Data As String)
Public Sub PacketArrived(IPH As clsIPHeader, ReadBuffer() As Byte, BytesRecieved As Long)
    Dim UDPH As UDPHeader
    Dim DataOffset                  As Integer
    Dim PayloadSize                 As Long
    Dim bPayload()                  As Byte
    Dim strPayload                  As String
    CopyMemory UDPH, ByVal VarPtr(ReadBuffer(0)) + 20, LenB(UDPH)
    DataOffset = 20 + LenB(UDPH)
    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
    Checksum = IntegerToUnsigned(ntohs(UDPH.udp_checksum))
    DestPort = ntohs(UDPH.dst_portno)
    HeaderLength = ntohs(UDPH.udp_length)
    SourcePort = ntohs(UDPH.src_portno)
    RaiseEvent RecievedPacket(IPH, Me, strPayload)
End Sub
Public Sub SendPacket(strDestination As String, DestPort As Long, IPHeader As clsIPHeader, Data As String)
    Dim IPH                         As IPHeader
    Dim UDPH                        As UDPHeader
    Dim Packet()                    As Byte
    Dim bData()                     As Byte
    With IPH
        .ip_checksum = htons(IPHeader.Checksum)
        .ip_destaddr = IPHeader.DestAddress
        .ip_id = htons(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 UDPH
        .dst_portno = htons(DestPort)
        .src_portno = htons(SourcePort)
        .udp_checksum = htons(Checksum)
        .udp_length = htons(HeaderLength)
    End With
    bData = StrConv(Data, vbFromUnicode)
    ReDim Packet(LenB(IPH) + LenB(UDPH) + UBound(bData))
    CopyMemory ByVal VarPtr(Packet(0)), ByVal VarPtr(IPH), LenB(IPH)
    CopyMemory ByVal VarPtr(Packet(0)) + LenB(IPH), ByVal VarPtr(UDPH), LenB(UDPH)
    CopyMemory ByVal VarPtr(Packet(0)) + LenB(IPH) + LenB(UDPH), 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 HeaderLength() As Integer
    HeaderLength = m_udp_length
End Property
Public Property Let HeaderLength(val As Integer)
    m_udp_length = val
End Property
Public Property Get Checksum() As Long
    Checksum = m_udp_checksum
End Property
Public Property Let Checksum(val As Long)
    m_udp_checksum = val
End Property