Client Socket avec domaine DNS Dynamique

Address gère un nom d'hote comme un nom de PC ou une IP
Mais une URL via le DNS
Il faut appeler l'API Windows qui effectue cette translation

Voici le code que j'ai écrit pour consulter les infos du DNS
Si tu laisses DNSServer vide cela utilise les deux IP de la configuration Windows
Si tu fournis une IP pour DNSServer, cela utilise d'abord ce serveur puis la configuration windows

Code:

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//---------------------------------------------------------------------------
TShaiDVRDahuaTechnology_Generic_Entity::TPropertyString __fastcall TShaiDVRDahuaTechnology_Generic_Entity::GetDeviceAddressIP()
{
  TPropertyString Result;
  switch (UseDNS)
  {
    case htAdressIP :
      Result = AddressIP;
    break;
 
    case htDNS :
      Result = TShaiDVRDahuaTechnology_DNSResolver::Query(URL);
    break;
 
    case htDNSExtra :
      if ( ! DNS1.IsEmpty())
        Result = TShaiDVRDahuaTechnology_DNSResolver::Query(URL, DNS1);
      if (Result.IsEmpty() && ! DNS2.IsEmpty())
        Result = TShaiDVRDahuaTechnology_DNSResolver::Query(URL, DNS2);
    break;
  }
 
  return Result;
}

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//---------------------------------------------------------------------------
//                  TShaiDVRDahuaTechnology_DNSResolver                    -
//---------------------------------------------------------------------------
#include <WinDNS.h>   //DNS api's
//---------------------------------------------------------------------------
class TShaiDVRDahuaTechnology_DNSResolver : public TObject
{
private:
  // Membres Privés
  static DNS_STATUS _LastQueryError;
 
public:
  // Méthodes Publiques
  static AnsiString Query(const AnsiString DNSName, const AnsiString DNSServer = "");
  static DNS_STATUS GetLastQueryError();
  static AnsiString GetLastQueryErrorMsg();
};

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//---------------------------------------------------------------------------
//                  TShaiDVRDahuaTechnology_DNSResolver                    -
//---------------------------------------------------------------------------
DNS_STATUS TShaiDVRDahuaTechnology_DNSResolver::_LastQueryError = ERROR_SUCCESS;
//---------------------------------------------------------------------------
/*static*/ AnsiString TShaiDVRDahuaTechnology_DNSResolver::Query(const AnsiString DNSName, const AnsiString DNSServer/* = ""*/)
{
  AnsiString Result;
 
  // Un Seul DNS à la fois avec DnsQuery sinon faudrait utiliser DnsQueryEx
  IP4_ARRAY SrvList;
  PIP4_ARRAY pSrvList = NULL;
  if ( ! DNSServer.IsEmpty())
  {
    SrvList.AddrCount = 1; // On ne peut pas affecter d'autres valeurs, le type IP4_ARRAY est limité à 1
    IP4_ADDRESS IPV4Value = inet_addr(DNSServer.c_str());
    if (IPV4Value != INADDR_NONE)
    {
      SrvList.AddrArray[0] = IPV4Value;
      pSrvList = &SrvList;
    }
  }
 
  PDNS_RECORD pDnsRecord; // Pointer to DNS_RECORD structure.
  // Calling function DnsQuery to query Host
  _LastQueryError = DnsQuery(DNSName.c_str(), // A pointer to a string that represents the DNS name to query.
    DNS_TYPE_A, // Type of the record to be queried.
    DNS_QUERY_STANDARD, // Bypasses the resolver cache on the lookup.
    pSrvList, // pExtra is reserved for future use but Contains DNS server IP address.
    &pDnsRecord, // Resource record that contains the response.
    NULL); // Reserved for future use.
 
  if (_LastQueryError == ERROR_SUCCESS)
  {
    IP4_ADDRESS IPV4Value = pDnsRecord->Data.A.IpAddress;
    DnsRecordListFree(pDnsRecord, DnsFreeRecordList);
 
    //convert the Internet network address into a string in Internet standard dotted format.
    IN_ADDR ipaddr;
    ipaddr.S_un.S_addr = IPV4Value;
    Result = inet_ntoa(ipaddr);
  }
 
  return Result;
}
 
//---------------------------------------------------------------------------
/*static*/ DNS_STATUS TShaiDVRDahuaTechnology_DNSResolver::GetLastQueryError()
{
  return _LastQueryError;
}
 
//---------------------------------------------------------------------------
/*static*/ AnsiString TShaiDVRDahuaTechnology_DNSResolver::GetLastQueryErrorMsg()
{
  return AnsiString().Format("%s [Error Code : %d]", ARRAYOFCONST((SysErrorMessage(_LastQueryError), _LastQueryError)));
}