#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef _WIN32
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #include <iphlpapi.h>
#else
 #include <arpa/inet.h>
 #include <sys/socket.h>
 #include <net/if.h>
#endif

static int isEqualIPv6Addr(const struct sockaddr_in6 *sa, const struct in6_addr in6Addr)
{
    return (memcmp(&(sa->sin6_addr), &in6Addr, sizeof(in6Addr)) == 0) ? 1 : 0;
}

void sockaddr_show(struct sockaddr *sa) {

     int family = sa->sa_family;

     if (family == AF_INET) {
         char buff[INET_ADDRSTRLEN];
         struct sockaddr_in server_addr = *((struct sockaddr_in*) sa);
         inet_ntop(AF_INET, &server_addr.sin_addr, buff, INET_ADDRSTRLEN);
         printf("AF_INET  IPv4 addr '%s'\n", buff);
     } else if (family == AF_INET6) {
         char buff[INET_ADDRSTRLEN];
         struct sockaddr_in6 server_addr = *((struct sockaddr_in6*) sa);
         struct in6_addr mappedAny = IN6ADDR_ANY_INIT;
         inet_pton(AF_INET6, "::ffff:0.0.0.0", &mappedAny);

         inet_ntop(AF_INET6, &server_addr.sin6_addr, buff, INET6_ADDRSTRLEN);
         printf("AF_INET6 IPv6 addr '%s', mappedAny: %d, in6addr_any: %d\n", buff,
                isEqualIPv6Addr(&server_addr, mappedAny), isEqualIPv6Addr(&server_addr, in6addr_any));
     } else {
         printf("family: %d\n", family);
     }
}

void show_addr_info(int family, int flags) {

     char* hostname = NULL;
     char* service = "0";

     struct addrinfo hints;
     struct addrinfo *result = NULL, *rp;

     memset (&hints, 0, sizeof(hints));

     hints.ai_family = family;
     hints.ai_socktype = SOCK_STREAM;
     hints.ai_protocol = IPPROTO_TCP;
     hints.ai_flags = AI_NUMERICSERV | flags;

#ifdef _WIN32
     WSADATA wsaData;
     WSAStartup(MAKEWORD(2, 2), &wsaData);
#endif

     int res = getaddrinfo(hostname, service, &hints, &result);
	 printf("res = %d\n", res);
     for (rp = result; rp != NULL; rp = rp->ai_next) {
         sockaddr_show(rp->ai_addr);
     }
     printf("\n");
}

int main(void) {

     printf("family: AF_UNSPEC, flags: AI_PASSIVE\n");
     show_addr_info(AF_UNSPEC, AI_PASSIVE);

     printf("family: AF_INET,   flags: AI_PASSIVE\n");
     show_addr_info(AF_INET,   AI_PASSIVE);

     printf("family: AF_INET6,  flags: AI_PASSIVE\n");
     show_addr_info(AF_INET6,  AI_PASSIVE);

     printf("family: AF_INET6,  flags: AI_PASSIVE | AI_V4MAPPED | AI_ALL\n");
     show_addr_info(AF_INET6,  AI_PASSIVE | AI_V4MAPPED | AI_ALL);

     return EXIT_SUCCESS;
}