windows xp下的ipv6地址转换

winsock2还没有关于ipv6的地址转换函数：inet_pton和inet_ntop
  
上网搜了一份实现的代码，如下：
  
#ifdef _WIN32
const char *inet_ntop(int af, const void *src, char *dst, socklen_t cnt)
{
     if (af == AF_INET)
     {
         struct sockaddr_in in;
         memset(&in, 0, sizeof(in));
         in.sin_family = AF_INET;
         memcpy(&in.sin_addr, src, sizeof(struct in_addr));
         getnameinfo((struct sockaddr *)&in, sizeof(struct sockaddr_in), dst, cnt, NULL, 0, NI_NUMERICHOST);
         return dst;
     }
     else if (af == AF_INET6)
     {
         struct sockaddr_in6 in;
         memset(&in, 0, sizeof(in));
         in.sin6_family = AF_INET6;
         memcpy(&in.sin6_addr, src, sizeof(struct in_addr6));
         getnameinfo((struct sockaddr *)&in, sizeof(struct sockaddr_in6), dst, cnt, NULL, 0, NI_NUMERICHOST);
         return dst;
     }
     return NULL;
}
  
int inet_pton(int af, const char *src, void *dst) //这个函数好像不行啊，
{
     struct addrinfo hints, *res, *ressave;
     memset(&hints, 0, sizeof(struct addrinfo));
     hints.ai_family = af;
  
     if (getaddrinfo(src, NULL, &hints, &res) != 0)
     {
         cout<<"Couldn't resolve host: "<<src<<endl;
         return -1;
     }
     ressave = res;
  
     while (res)
     {
         memcpy(dst, res->ai_addr, res->ai_addrlen);
         res = res->ai_next;
     }
  
     freeaddrinfo(ressave);
     return 0;
} 
  
#endif

//这个是可以用的

 struct addrinfo hints = { 0 };

 struct addrinfo *res;

 int gai_err;  

if(iptype==1)   //根据ip类型选择地址族

　　hints.ai_family = AF_INET6;  

else  

 　　hints.ai_family = AF_INET;  

hints.ai_socktype = SOCK_STREAM;

 gai_err = getaddrinfo(host,"9000",&hints,&res); //其中第二个参数自己设置啊

 if(gai_err)  return FALSE;

 if(connect(sock,res->ai_addr,res->ai_addrlen) == SOCKET_ERROR)  {//其实也可以用非阻塞socket实现，这里是阻塞socket去connect的,需要三次握手的

 　  DWORD qq = WSAGetLastError();   

　　return FALSE;  

}

return TRUE;