CSocket的获取socket的local/peer的ip, port,addressfamily

使用getsockname来获取一个socket的local和remote的ip, 端口， address family等信息
的操作。
wxString CSocket::GetLocalIP() const
{
    struct sockaddr_storage addr;
    socklen_t addr_len = sizeof(addr);
    int res = getsockname(m_fd, (sockaddr*)&addr, &addr_len);
    if (res)
        return _T("");

    return AddressToString((sockaddr *)&addr, addr_len, false);
}

wxString CSocket::GetPeerIP() const
{
    struct sockaddr_storage addr;
    socklen_t addr_len = sizeof(addr);
    int res = getpeername(m_fd, (sockaddr*)&addr, &addr_len);
    if (res)
        return _T("");

    return AddressToString((sockaddr *)&addr, addr_len, false);
}

int CSocket::GetAddressFamily() const
{
    struct sockaddr_storage addr;
    socklen_t addr_len = sizeof(addr);
    int res = getsockname(m_fd, (sockaddr*)&addr, &addr_len);
    if (res)
        return AF_UNSPEC;

    return ((sockaddr*)&addr)->sa_family;
}

int CSocket::GetLocalPort(int& error)
{
    struct sockaddr_storage addr;
    socklen_t addr_len = sizeof(addr);
    error = getsockname(m_fd, (sockaddr*)&addr, &addr_len);
    if (error)
    {
#ifdef __WXMSW__
        error = ConvertMSWErrorCode(error);
#endif
        return -1;
    }

    if (addr.ss_family == AF_INET)
    {
        struct sockaddr_in* addr_v4 = (sockaddr_in*)&addr;
        return ntohs(addr_v4->sin_port);
    }
    else if (addr.ss_family == AF_INET6)
    {
        struct sockaddr_in6* addr_v6 = (sockaddr_in6*)&addr;
        return ntohs(addr_v6->sin6_port);
    }

    error = EINVAL;
    return -1;
}

int CSocket::GetRemotePort(int& error)
{
    struct sockaddr_storage addr;
    socklen_t addr_len = sizeof(addr);
    error = getpeername(m_fd, (sockaddr*)&addr, &addr_len);
    if (error)
    {
#ifdef __WXMSW__
        error = ConvertMSWErrorCode(error);
#endif
        return -1;
    }

    if (addr.ss_family == AF_INET)
    {
        struct sockaddr_in* addr_v4 = (sockaddr_in*)&addr;
        return ntohs(addr_v4->sin_port);
    }
    else if (addr.ss_family == AF_INET6)
    {
        struct sockaddr_in6* addr_v6 = (sockaddr_in6*)&addr;
        return ntohs(addr_v6->sin6_port);
    }

    error = EINVAL;
    return -1;
}