tcpkeepalive: support TCP_KEEPIDLE/TCP_KEEPINTVL on win32

static bool verifyconnect(curl_socket_t sockfd, int *error);

#ifdef __DragonFly__

/* DragonFlyBSD uses millisecond as KEEPIDLE and KEEPINTVL units */

#if defined(__DragonFly__) || defined(HAVE_WINSOCK_H)

/* DragonFlyBSD and Windows use millisecond units */

#define KEEPALIVE_FACTOR(x) (x *= 1000)

#else

#define KEEPALIVE_FACTOR(x)

#endif

#if defined(HAVE_WINSOCK_H) && !defined(SIO_KEEPALIVE_VALS)

#define SIO_KEEPALIVE_VALS    _WSAIOW(IOC_VENDOR,4)

struct tcp_keepalive {

  u_long onoff;

  u_long keepalivetime;

  u_long keepaliveinterval;

};

#endif

static void

tcpkeepalive(struct SessionHandle *data,

             curl_socket_t sockfd)

    infof(data, "Failed to set SO_KEEPALIVE on fd %d\n", sockfd);

  }

  else {

#if defined(SIO_KEEPALIVE_VALS)

    struct tcp_keepalive vals;

    DWORD dummy;

    vals.onoff = 1;

    optval = curlx_sltosi(data->set.tcp_keepidle);

    KEEPALIVE_FACTOR(optval);

    vals.keepalivetime = optval;

    optval = curlx_sltosi(data->set.tcp_keepintvl);

    KEEPALIVE_FACTOR(optval);

    vals.keepaliveinterval = optval;

    if (WSAIoctl(sockfd, SIO_KEEPALIVE_VALS, (LPVOID) &vals, sizeof(vals),

                 NULL, 0, &dummy, NULL, NULL) != 0) {

      infof(data, "Failed to set SIO_KEEPALIVE_VALS on fd %d: %d\n",

            (int)sockfd, WSAGetLastError());

    }

#else

#ifdef TCP_KEEPIDLE

    optval = curlx_sltosi(data->set.tcp_keepidle);

    KEEPALIVE_FACTOR(optval);

          (void *)&optval, sizeof(optval)) < 0) {

      infof(data, "Failed to set TCP_KEEPINTVL on fd %d\n", sockfd);

    }

#endif

#endif

  }

}