private static List<IPConnection> queryTCPv4Connections() {
        List<IPConnection> conns = new ArrayList<>();
        // Get size needed
        try (CloseableIntByReference sizePtr = new CloseableIntByReference()) {
            int ret = IPHLP.GetExtendedTcpTable(null, sizePtr, false, AF_INET, TCP_TABLE_OWNER_PID_ALL, 0);
            if (ret == WinError.ERROR_SUCCESS) {
                // Get buffer and populate table
                int size = sizePtr.getValue();
                Memory buf = new Memory(size);
                do {
                    ret = IPHLP.GetExtendedTcpTable(buf, sizePtr, false, AF_INET, TCP_TABLE_OWNER_PID_ALL, 0);
                    if (ret == WinError.ERROR_INSUFFICIENT_BUFFER) {
                        size = sizePtr.getValue();
                        buf.close();
                        buf = new Memory(size);
                    }
                } while (ret == WinError.ERROR_INSUFFICIENT_BUFFER);
                MIB_TCPTABLE_OWNER_PID tcpTable = new MIB_TCPTABLE_OWNER_PID(buf);
                for (int i = 0; i < tcpTable.dwNumEntries; i++) {
                    MIB_TCPROW_OWNER_PID row = tcpTable.table[i];
                    conns.add(new IPConnection("tcp4", ParseUtil.parseIntToIP(row.dwLocalAddr),
                            ParseUtil.bigEndian16ToLittleEndian(row.dwLocalPort),
                            ParseUtil.parseIntToIP(row.dwRemoteAddr),
                            ParseUtil.bigEndian16ToLittleEndian(row.dwRemotePort), stateLookup(row.dwState), 0, 0,
                            row.dwOwningPid));
                }
                buf.close();
            }
        }
        return conns;
    }