Comment obtenir le nom de domaine de Given IP dans MFC (VC++)?

Question

Comment obtenir le nom de domaine de Given IP dans MFC (VC++)? Le code que je utilise est comme ci-dessous:

#include "stdafx.h" 
#include <winsock2.h> 
#include <ws2tcpip.h> 
#include <stdio.h> 

// link with ws2_32.lib 
#pragma comment(lib, "Ws2_32.lib") 


int _tmain(int argc, char **argv) 
{ 

    //----------------------------------------- 
    // Declare and initialize variables 
    WSADATA wsaData = {0}; 
    int iResult = 0; 

    DWORD dwRetval; 

    struct sockaddr_in saGNI; 
    char hostname[NI_MAXHOST]; 
char servInfo[NI_MAXSERV]; 
u_short port = 27015; 


// Initialize Winsock 
iResult = WSAStartup(MAKEWORD(2, 2), &wsaData); 
if (iResult != 0) { 
    printf("WSAStartup failed: %d\n", iResult); 
    return 1; 
} 
//----------------------------------------- 
// Set up sockaddr_in structure which is passed 
// to the getnameinfo function 
saGNI.sin_family = AF_INET; 
saGNI.sin_addr.s_addr = inet_addr(argv[1]); 
saGNI.sin_port = htons(port); 

//----------------------------------------- 
// Call getnameinfo 
dwRetval = getnameinfo((struct sockaddr *) &saGNI, 
         sizeof (struct sockaddr), 
         hostname, 
         NI_MAXHOST, servInfo, NI_MAXSERV, NI_NUMERICSERV); 

if (dwRetval != 0) { 
    printf("getnameinfo failed with error # %ld\n", WSAGetLastError()); 
    return 1; 
} else { 
    printf("getnameinfo returned hostname = %s\n", hostname); 
    return 0; 
} 

} Ce code me retourne le nom d'hôte comme = 255.255.255.255 pas le nom de domaine.

Answer 1

int WSAAPI getnameinfo(
    __in const struct sockaddr FAR *sa, 
    __in socklen_t salen, 
    __out char FAR *host, 
    __in DWORD hostlen, 
    __out char FAR *serv, 
    __in DWORD servlen, 
    __in int flags 
); 

http://msdn.microsoft.com/en-us/library/ms738532(v=VS.85).aspx

Cet appel API réprouve gethostbyaddr.