FTP 欢迎消息的最大大小是多少?

What is the maximum size for an FTP welcome message?

为了避免FTP欢迎消息中的缓冲区溢出,它的最大大小是多少?

我知道它可以包含多行,例如:

220-QTCP at fran.csg.stercomm.com.
220 Connection will close if idle more than 5 minutes.

但是是否有关于它应该包含多少行或字符的规范?

谢谢,

FTP 规范中通常没有规定限制。

引用 RFC 624 section 5:

  1. There is no specified maximum length of a TELNET command line, TELNET reply line, user name, password, account, or pathname.

引用“TELNET线路”因为FTP控制连接使用TELNET协议格式。引用 RFC 959 section 2.2:

control connection

The communication path between the USER-PI and SERVER-PI for the exchange of commands and replies. This connection follows the Telnet Protocol.