how to get value form the param (char * ip_buf)

I want to Call the method from a framework in iOS Platform. the method is : +(int) getProxyTcpByIp:(const char*)token : (const char*)group_name :(const char*)dip :(const char*)dport : (char*) ip_buf : (int) ip_buf_len : (char*) port_buf : (int) port_buf_len; How to write the C# method to bind the iOS method?(how to get the value of ip_buf and port_buf ?)