Hostname

ShowInfo.cpp

/*NOTA:
1) tem que se garantir que o windows.h é compilado sempre após o ws2tcpip.h, 
  	caso contrário começa a indicar que há referencias duplicadas. 

2) Quando se trabalha com sockets tem sempre que se inicializar a WinSockDLL -> tag WSAStartup */


#include <Ws2tcpip.h>

void ShowInfo(struct addrinfo *res)
{
  struct sockaddr_in *sockaddr_ipv4;
	LPSOCKADDR sockaddr_ip;
	char ipstringbuffer[46];
	DWORD ipbufferlength = 46;
	INT iRetval;

	switch(res->ai_family)
	{
		case AF_UNSPEC:
			printf("Unspecified\n");
			break;

		case AF_INET:
			printf("AF_INET (IPv4)\n");
			sockaddr_ipv4 = (struct sockaddr_in *) res->ai_addr;
			printf("\tIPv4 address %s\n",inet_ntoa(sockaddr_ipv4->sin_addr) );
			break;

		case AF_INET6:
			printf("AF_INET6 (IPv6)\n");
			// the InetNtop function is available on Windows Vista and later
			// sockaddr_ipv6 = (struct sockaddr_in6 *) ptr->ai_addr;
			// printf("\tIPv6 address %s\n",
			//    InetNtop(AF_INET6, &sockaddr_ipv6->sin6_addr, ipstringbuffer, 46) );

			// We use WSAAddressToString since it is supported on Windows XP and later
			sockaddr_ip = (LPSOCKADDR) res->ai_addr;
			// The buffer length is changed by each call to WSAAddresstoString
			// So we need to set it for each iteration through the loop for safety
			ipbufferlength = 46;
			iRetval = WSAAddressToString(sockaddr_ip, (DWORD) res->ai_addrlen, NULL, 
				ipstringbuffer, &ipbufferlength );
			
			if (iRetval)
				printf("WSAAddressToString failed with %u\n", WSAGetLastError() );
			else    
				printf("\tIPv6 address %s\n", ipstringbuffer);
			break;

		default:
			break;
	}
}
//
//
//
bool ConvertCharIPToAddrInfo(char* addrOne,struct addrinfo*& pResult) //ex: pc-rteste or 127.0.0.1 or localhost (whatever u like :)
{
	int error = getaddrinfo(addrOne,NULL,NULL,&pResult);
	
	if(error == 0)
		return true;
}

bool ShowHostnameFromAddrInfo(struct addrinfo *result)
{
	char hostname_res[NI_MAXHOST] = "";
	
	int error;
	struct addrinfo *res;
	for (res = result; res != NULL; res = res->ai_next)
	{
		error = getnameinfo(res->ai_addr, res->ai_addrlen, hostname_res, NI_MAXHOST, NULL, 0, 0); 
		
		if (error != 0)
		{
			fprintf(stderr, "error in getnameinfo: %s\n", gai_strerror(error));
			return false;
		}
		
		if (*hostname_res == '\0')
		{
			printf("no hostname found\n");
			return false;
		}
		
		printf("hostname: %s\n", hostname_res);
	}
	
	return true;
}