get ipv6 address from Windows

GetIpv6TemporaryAddress.cpp

#include <iostream>
#include <winsock2.h>
#include <iphlpapi.h>
#include <WS2tcpip.h>
#pragma comment(lib, "IPHLPAPI.lib")
#pragma comment(lib, "Ws2_32.lib")

using namespace std;

static char* ConvertLPWSTRToLPSTR(LPWSTR lpwszStrIn)
{
    LPSTR pszOut = NULL;
    if (lpwszStrIn != NULL)
    {
        int nInputStrLen = (int)wcslen(lpwszStrIn);

        // Double NULL Termination
        int nOutputStrLen = WideCharToMultiByte(CP_ACP, 0, lpwszStrIn, nInputStrLen, NULL, 0, 0, 0) + 2;
        pszOut = new char[nOutputStrLen];

        if (pszOut)
        {
            memset(pszOut, 0x00, nOutputStrLen);
            WideCharToMultiByte(CP_ACP, 0, lpwszStrIn, nInputStrLen, pszOut, nOutputStrLen, 0, 0);
        }
    }
    return pszOut;

}

std::string GetIpv6TemporaryAddress()
{
    IP_ADAPTER_ADDRESSES *adapterAddr;
    DWORD dwSize = 0;
    DWORD flags = GAA_FLAG_INCLUDE_PREFIX | GAA_FLAG_SKIP_MULTICAST | GAA_FLAG_SKIP_MULTICAST | GAA_FLAG_SKIP_DNS_SERVER;

    DWORD dwRet = GetAdaptersAddresses(AF_UNSPEC, flags, NULL, NULL, &dwSize);
    if (dwRet == ERROR_BUFFER_OVERFLOW) {
        adapterAddr = (IP_ADAPTER_ADDRESSES *)LocalAlloc(LMEM_ZEROINIT, dwSize);
        if (adapterAddr == NULL) {
            cout << "Can't query for adapter addresses - LocalAlloc error" << endl;
        }
        dwRet = GetAdaptersAddresses(AF_UNSPEC, flags, NULL, adapterAddr, &dwSize);
        if (dwRet != ERROR_SUCCESS) {
            LocalFree(adapterAddr);
            cout << "Can't query for adapter addresses - GetAdapterAddresses" << endl;;
        }
        else {
            IP_ADAPTER_ADDRESSES *AI;
            int i;
            for (i = 0, AI = adapterAddr; AI != NULL; AI = AI->Next, i++) {
                if (AI->FirstUnicastAddress != NULL) {
                    LPSTR strAdapterFriendlyName = ConvertLPWSTRToLPSTR(AI->FriendlyName);
                    string adapterFriendlyName(strAdapterFriendlyName);
                    delete[] strAdapterFriendlyName;

                    cout << "Adapter name : " <<  AI->AdapterName << endl;;
                    cout << "Adapter friendly name : " << adapterFriendlyName.c_str() << endl;
                    int count = 0;
                    for (PIP_ADAPTER_UNICAST_ADDRESS unicast = AI->FirstUnicastAddress; unicast; unicast = unicast->Next) {
                        struct sockaddr &addr = *unicast->Address.lpSockaddr;
                        const struct sockaddr_in6* addr6 = reinterpret_cast<const sockaddr_in6*>(&addr);
                        char ipv6Addr[262];
                        memset(ipv6Addr, '\0', 262);
                        inet_ntop(AF_INET6, &addr6->sin6_addr, ipv6Addr, 262);

                        string strIpAddr(ipv6Addr);
                        cout << "Found IPV6 : " << strIpAddr.c_str() << endl;

                        if (unicast->SuffixOrigin == IpSuffixOriginRandom) {
                            cout << "This is temporary address!" << endl;
                            return strIpAddr;
                        }
                    }
                }
            }
            LocalFree(adapterAddr);
        }
    }
    return "";
}

int main(int argc, const char * argv[]) {
    GetIpv6TemporaryAddress();
    return 0;
}