如何从 LPRT ftp 命令获取 IPv6

Question

我正在创建一个 FTP 服务器。根据 FTP 规范，他们添加了名为 LPRT 的新命令。

它的格式是LPRT 6,16,0,0,0,0,0,0,0,0,3,0,0,0,0,0,0,0,2,193,160

现在我可以使用逻辑从中获取 FTP 端口 below.But 我还需要此字符串中的 IPV6 地址。

public static void main(String[] args) {
    StringTokenizer st = new StringTokenizer(
            "6,16,0,0,0,0,0,0,0,0,3,0,0,0,0,0,0,0,2,193,160");

      final String portStr = st.nextToken(); 
      final int lastDelimIdx =portStr.lastIndexOf(',', portStr.lastIndexOf(',') - 1);
      final StringTokenizer portst = new StringTokenizer(portStr.substring(lastDelimIdx + 1, portStr.length()), ",");
      final int p1 = Integer.parseInt(portst.nextToken());
      final int p2 = Integer.parseInt(portst.nextToken());
      final int dataPort = (p1 << 8) | p2;
      System.out.println(dataPort);
}

谁能帮我从这个字符串中找到 IPv6 地址。

Answer 1

LPRT 和 LPSV 被认为已过时，请参阅 https://www.iana.org/assignments/ftp-commands-extensions/ftp-commands-extensions.txt. To use IPv6 use EPSV and EPRT which are specified in RFC2428。

如果您仍然需要知道如何处理 LPRT，请查看已过时的 RFC1639。例如：

LPRT 6,16,0,0,0,0,0,0,0,0,3,0,0,0,0,0,0,0,2,193,160

表示主机长度参数后面的16个数字是地址的字节，然后是端口地址长度后跟2个字节，即

[0000:0000:0000:0000:0300:0000:0000:0000]:49568

Answer 2

我创建了一个执行此提取的程序

    public static String longToIP(long[] ip) {
    String ipString = "";

    int flag = 0;
    for (long crtLong : ip) {

        if (flag == 2) {
            ipString = ipString + ":";
            flag = 0;
        }
        String s = Long.toHexString(crtLong & 0xFFFFFFFFL);
        if (s.length() == 1) {
            s = "0" + s;
        }
        ipString = ipString + "" + s;
        flag++;

    }
    return ipString;

}

输入 = { 0,0,0,0,0,0,0,0,3,0,0,0,0,0,0,0 }

输出 = {0000:0000:0000:0000:0300:0000:0000:0000}

如何从 LPRT ftp 命令获取 IPv6

How to get IPv6 from LPRT ftp command

java

ftp