353 lines
8.5 KiB
C++
353 lines
8.5 KiB
C++
/*++
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Copyright (c) 1994 Microsoft Corporation
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Module Name :
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cdns.h
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Abstract:
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This module defines the DNS connection class.
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Author:
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Rohan Phillips ( Rohanp ) 07-May-1998
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Project:
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Revision History:
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--*/
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# ifndef _ADNS_CLIENT_HXX_
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# define _ADNS_CLIENT_HXX_
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/************************************************************
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* Include Headers
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************************************************************/
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#include <dnsreci.h>
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//
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// Redefine the type to indicate that this is a call-back function
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//
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typedef ATQ_COMPLETION PFN_ATQ_COMPLETION;
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/************************************************************
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* Symbolic Constants
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************************************************************/
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//
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// Valid & Invalid Signatures for Client Connection object
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// (Ims Connection USed/FRee)
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//
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# define DNS_CONNECTION_SIGNATURE_VALID 'DNSU'
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# define DNS_CONNECTION_SIGNATURE_FREE 'DNSF'
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//
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// POP3 requires a minimum of 10 minutes before a timeout
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// (SMTP doesn't specify, but might as well follow POP3)
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//
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# define MINIMUM_CONNECTION_IO_TIMEOUT (10 * 60) // 10 minutes
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//
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//
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#define DNS_TCP_DEFAULT_PACKET_LENGTH (0x4000)
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enum DNSLASTIOSTATE
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{
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DNS_READIO, DNS_WRITEIO
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};
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typedef struct _DNS_OVERLAPPED
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{
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OVERLAPPED Overlapped;
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DNSLASTIOSTATE LastIoState;
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} DNS_OVERLAPPED;
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/************************************************************
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* Type Definitions
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************************************************************/
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/*++
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class CLIENT_CONNECTION
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This class is used for keeping track of individual client
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connections established with the server.
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It maintains the state of the connection being processed.
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In addition it also encapsulates data related to Asynchronous
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thread context used for processing the request.
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--*/
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class CAsyncDns
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{
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private:
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ULONG m_signature; // signature on object for sanity check
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LONG m_cPendingIoCount;
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LONG m_cThreadCount;
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DWORD m_cbReceived;
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DWORD m_BytesToRead;
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DWORD m_dwIpServer;
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BOOL m_fUdp;
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BOOL m_FirstRead;
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PDNS_MESSAGE_BUFFER m_pMsgRecv;
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BYTE *m_pMsgRecvBuf;
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PDNS_MESSAGE_BUFFER m_pMsgSend;
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BYTE *m_pMsgSendBuf;
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WORD m_cbSendBufSize;
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SOCKADDR_IN m_RemoteAddress;
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PATQ_CONTEXT m_pAtqContext;
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SOCKET m_DnsSocket; // socket for this connection
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BOOL m_fIsGlobalDnsList;
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protected:
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DWORD m_dwFlags;
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char m_HostName [MAX_PATH];
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CDnsServerList *m_pTcpRegIpList;
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//
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// The overlapped structure for reads (one outstanding read at a time)
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// -- writes will dynamically allocate them
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//
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DNS_OVERLAPPED m_ReadOverlapped;
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DNS_OVERLAPPED m_WriteOverlapped;
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SOCKET QuerySocket( VOID) const
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{ return ( m_DnsSocket); }
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PATQ_CONTEXT QueryAtqContext( VOID) const
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{ return ( m_pAtqContext); }
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LPOVERLAPPED QueryAtqOverlapped( void ) const
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{ return ( m_pAtqContext == NULL ? NULL : &m_pAtqContext->Overlapped ); }
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DWORD QueryDnsServer() { return m_dwIpServer; }
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BOOL IsUdp() { return m_fUdp; }
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//
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// DNS server failover is disabled if this query was a TCP failover query
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// kicked off because of UDP truncation.
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//
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BOOL FailoverDisabled() { return ((m_dwFlags == DNS_FLAGS_NONE) && !m_fUdp); }
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public:
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CAsyncDns();
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virtual ~CAsyncDns(VOID);
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DNS_STATUS DnsSendRecord();
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DNS_STATUS Dns_OpenTcpConnectionAndSend();
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DNS_STATUS Dns_Send( );
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DNS_STATUS SendPacket( void);
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DNS_STATUS Dns_QueryLib(
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DNS_NAME pszQuestionName,
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WORD wQuestionType,
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DWORD dwFlags,
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BOOL fUdp,
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CDnsServerList *pTcpRegIpList,
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BOOL fIsGlobalDnsList);
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SOCKET Dns_CreateSocket( IN INT SockType );
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//BOOL MakeDnsConnection(void);
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//
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// IsValid()
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// o Checks the signature of the object to determine
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//
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// Returns: TRUE on success and FALSE if invalid.
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//
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BOOL IsValid( VOID) const
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{
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return ( m_signature == DNS_CONNECTION_SIGNATURE_VALID);
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}
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//-------------------------------------------------------------------------
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// Virtual method that MUST be defined by derived classes.
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//
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// Processes a completed IO on the connection for the client.
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//
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// -- Calls and maybe called from the Atq functions.
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//
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virtual BOOL ProcessClient(
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IN DWORD cbWritten,
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IN DWORD dwCompletionStatus,
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IN OUT OVERLAPPED * lpo
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) ;
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CDnsServerList *GetDnsList()
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{
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return m_pTcpRegIpList;
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}
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//
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// Returns a copy the IP_ARRAY in the DNS-serverlist for this CAsyncDns
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// Returns NULL if the DNS-serverlist is the default global-list of DNS
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// servers on this box. Otherwise, the pipArray returned should be deleted
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// using ReleaseDnsIpArray() by the caller. On failure to allocate memory,
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// FALSE is returned.
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//
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BOOL GetDnsIpArrayCopy(PIP_ARRAY *ppipArray)
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{
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if(m_fIsGlobalDnsList) {
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*ppipArray = NULL;
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return TRUE;
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}
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return m_pTcpRegIpList->CopyList(ppipArray);
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}
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void ReleaseDnsIpArray(PIP_ARRAY pipArray)
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{
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if(pipArray)
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delete pipArray;
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}
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LONG IncPendingIoCount(void)
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{
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LONG RetVal;
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RetVal = InterlockedIncrement( &m_cPendingIoCount );
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return RetVal;
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}
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LONG DecPendingIoCount(void) { return InterlockedDecrement( &m_cPendingIoCount );}
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LONG IncThreadCount(void)
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{
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LONG RetVal;
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RetVal = InterlockedIncrement( &m_cThreadCount );
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return RetVal;
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}
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LONG DecThreadCount(void) { return InterlockedDecrement( &m_cThreadCount );}
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BOOL ReadFile(
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IN LPVOID pBuffer,
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IN DWORD cbSize /* = MAX_READ_BUFF_SIZE */
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);
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BOOL WriteFile(
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IN LPVOID pBuffer,
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IN DWORD cbSize /* = MAX_READ_BUFF_SIZE */
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);
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BOOL ProcessReadIO(IN DWORD InputBufferLen,
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IN DWORD dwCompletionStatus,
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IN OUT OVERLAPPED * lpo);
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void DisconnectClient(void);
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// Virtual functions to implement app-specific processing
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virtual void DnsProcessReply(
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IN DWORD dwStatus,
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IN PDNS_RECORD pRecordList) = 0;
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virtual BOOL RetryAsyncDnsQuery(BOOL fUdp) = 0;
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public:
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//
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// LIST_ENTRY object for storing client connections in a list.
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//
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LIST_ENTRY m_listEntry;
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LIST_ENTRY & QueryListEntry( VOID)
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{ return ( m_listEntry); }
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};
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typedef CAsyncDns * PCAsyncDns;
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class CAsyncMxDns : public CAsyncDns
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{
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protected:
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//
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// SMTP DNS specific members
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//
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DWORD m_LocalPref;
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BOOL m_SeenLocal;
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DWORD m_Index;
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DWORD m_Weight [100];
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DWORD m_Prefer [100];
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BOOL m_fUsingMx;
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char m_FQDNToDrop [MAX_PATH];
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PSMTPDNS_RECS m_AuxList;
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BOOL m_fMxLoopBack;
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public:
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CAsyncMxDns(char *MyFQDN);
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BOOL GetMissingIpAddresses(PSMTPDNS_RECS pDnsList);
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BOOL GetIpFromDns(PSMTPDNS_RECS pDnsRec, DWORD Count);
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BOOL CheckMxLoopback();
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void ProcessMxRecord(PDNS_RECORD pnewRR);
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void ProcessARecord(PDNS_RECORD pnewRR);
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BOOL SortMxList(void);
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BOOL CheckList(void);
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void DnsProcessReply(
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IN DWORD dwStatus,
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IN PDNS_RECORD pRecordList);
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//
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// The following functions allow SMTP to do SMTP connection specific
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// processing after the MX resolution is over
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//
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virtual void HandleCompletedData(DNS_STATUS) = 0;
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virtual BOOL IsShuttingDown() = 0;
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virtual BOOL IsAddressMine(DWORD dwIp) = 0;
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};
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//
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// Auxiliary functions
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//
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INT ShutAndCloseSocket( IN SOCKET sock);
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DWORD ResolveHost(
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LPSTR pszHost,
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PIP_ARRAY pipDnsServers,
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DWORD fOptions,
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DWORD *rgdwIpAddresses,
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DWORD *pcbIpAddresses);
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# endif
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/************************ End of File ***********************/
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