Hi All! Знатоки WinSock! Подскажите, как реализовать проверку наличия компа в сети по IP адресу? Есть листинг, но его нужно до ума довести. А то процесс пинга идёт слишком долго... Помогите пожалуйста убрать отсюда всё лишнее, в т.ч. DNS, да и посылка пакетов 4 раза нафиг не нужна, так как нас интересует только факт наличия компа в сети, то бишь return true or false...

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#include <vcl.h>
#include <windows.h>
#include <winsock.h>
#include <stdio.h>
#include <string.h>
#include <windows.h>
#include <winsock.h>
#include <stdio.h>
#include <string.h>
#pragma hdrstop

//---------------------------------------------------------------------------

typedef struct tagIPINFO
{
u_char Ttl; // Time To Live
u_char Tos; // Type Of Service
u_char IPFlags; // IP flags
u_char OptSize; // Size of options data
u_char FAR *Options; // Options data buffer
}IPINFO, *PIPINFO;

typedef struct tagICMPECHO
{
u_long Source; // Source address
u_long Status; // IP status
u_long RTTime; // Round trip time in milliseconds
u_short DataSize; // Reply data size
u_short Reserved; // Unknown
void FAR *pData; // Reply data buffer
IPINFO ipInfo; // Reply options
}ICMPECHO, *PICMPECHO;


// ICMP.DLL Export Function Pointers
HANDLE (WINAPI *pIcmpCreateFile)(VOID);
BOOL (WINAPI *pIcmpCloseHandle)(HANDLE);
DWORD (WINAPI *pIcmpSendEcho)
(HANDLE,DWORD,LPVOID,WORD,PIPINFO,LPVOID,DWORD,DWORD);

//
//
int main(int argc, char **argv)
{
WSADATA wsaData; // WSADATA
ICMPECHO icmpEcho; // ICMP Echo reply buffer
HANDLE hndlIcmp; // LoadLibrary() handle to ICMP.DLL
HANDLE hndlFile; // Handle for IcmpCreateFile()
LPHOSTENT pHost; // Pointer to host entry structure
struct in_addr iaDest; // Internet address structure
DWORD *dwAddress; // IP Address
IPINFO ipInfo; // IP Options structure
int nRet; // General use return code
DWORD dwRet; // DWORD return code
int x;

// Check arguments
if (argc != 2)
{
fprintf(stderr,"\nSyntax: pingi HostNameOrIPAddress\n");
// return;
}

// Dynamically load the ICMP.DLL
hndlIcmp = LoadLibrary("ICMP.DLL");
if (hndlIcmp == NULL)
{
fprintf(stderr,"\nCould not load ICMP.DLL\n");
return 0;
}
// Retrieve ICMP function pointers
pIcmpCreateFile = (HANDLE (WINAPI *)(void))
GetProcAddress(hndlIcmp,"IcmpCreateFile");
pIcmpCloseHandle = (BOOL (WINAPI *)(HANDLE))
GetProcAddress(hndlIcmp,"IcmpCloseHandle");
pIcmpSendEcho = (DWORD (WINAPI *)
(HANDLE,DWORD,LPVOID,WORD,PIPINFO,LPVOID,DWORD,DWORD))
GetProcAddress(hndlIcmp,"IcmpSendEcho");
// Check all the function pointers
if (pIcmpCreateFile == NULL ||
pIcmpCloseHandle == NULL ||
pIcmpSendEcho == NULL)
{
fprintf(stderr,"\nError getting ICMP proc address\n");
FreeLibrary(hndlIcmp);
return 0;
}

// Init WinSock
nRet = WSAStartup(0x0101, &wsaData );
if (nRet)
{
fprintf(stderr,"\nWSAStartup() error: %d\n", nRet);
WSACleanup();
FreeLibrary(hndlIcmp);
return 0;
}
// Check WinSock version
if (0x0101 != wsaData.wVersion)
{
fprintf(stderr,"\nWinSock version 1.1 not supported\n");
WSACleanup();
FreeLibrary(hndlIcmp);
return 0;
}

// Lookup destination
// Use inet_addr() to determine if we're dealing with a name
// or an address
iaDest.s_addr = inet_addr(argv[1]);
if (iaDest.s_addr == INADDR_NONE)
pHost = gethostbyname(argv[1]);
else
pHost = gethostbyaddr((const char *)&iaDest,
sizeof(struct in_addr), AF_INET);
if (pHost == NULL)
{
fprintf(stderr, "\n%s not found\n", argv[1]);
WSACleanup();
FreeLibrary(hndlIcmp);
return 0;
}

// Tell the user what we're doing
printf("\nPinging %s [%s]", pHost->h_name,
inet_ntoa((*(LPIN_ADDR)pHost->h_addr_list[0])));

// Copy the IP address
dwAddress = (DWORD *)(*pHost->h_addr_list);

// Get an ICMP echo request handle
hndlFile = pIcmpCreateFile();
for (x = 0; x < 4; x++)
{
// Set some reasonable default values
ipInfo.Ttl = 255;
ipInfo.Tos = 0;
ipInfo.IPFlags = 0;
ipInfo.OptSize = 0;
ipInfo.Options = NULL;
//icmpEcho.ipInfo.Ttl = 256;
// Reqest an ICMP echo
dwRet = pIcmpSendEcho(
hndlFile, // Handle from IcmpCreateFile()
*dwAddress, // Destination IP address
NULL, // Pointer to buffer to send
0, // Size of buffer in bytes
&ipInfo, // Request options
&icmpEcho, // Reply buffer
sizeof(struct tagICMPECHO),
5000); // Time to wait in milliseconds
// Print the results
iaDest.s_addr = icmpEcho.Source;
printf("\nReply from %s Time=%ldms TTL=%d",
inet_ntoa(iaDest),
icmpEcho.RTTime,
icmpEcho.ipInfo.Ttl);
if (icmpEcho.Status)
{
printf("\nError: icmpEcho.Status=%ld",
icmpEcho.Status);
break;
}
}
printf("\n");
// Close the echo request file handle
pIcmpCloseHandle(hndlFile);
FreeLibrary(hndlIcmp);
WSACleanup();
}
//---------------------------------------------------------------------------