虽然在嵌入式系统中，我们可以通过串口的Xmodem模式传送小的文件，但是毕竟不符合我们的使用习惯，并且串口传输速率太低，不能满足我们大部分的需求，要传输文件的时候，我们还是使用网络较为熟悉，今天我将我的ftp的笔记整理一下，分享给大家。

1.何为FTP

FTP（File Transfer Protocol，文件传输协议）是 TCP/IP 协议组中的协议之一。 FTP 协议包括两个组成部分，其一为 FTP 服务器，其二为 FTP 客户端。其中 FTP 服务器用来存储文件，用户可以使用 FTP客户端通过 FTP 协议访问位于 FTP 服务器上的资源。由于 FTP 传输效率非常高，在网络上传输大的文件时， 经常采用该协议。

默认情况下 FTP 协议使用 TCP 端口中的 20 和 21 这两个端口，其中 20 用于传输数据， 21 用于传输控制信息。但是，是否使用 20 作为传输数据的端口与 FTP 使用的传输模式有关，如果采用主动模式，那么数据传输端口就是 20；如果采用被动模式，则具体最终使用哪个端口要服务器端和客户端协商决定。

vsftpd 则是 very secure FTP daemon 的缩写，它是 UNIX 类操作系统上运行的服务器的名字，它可以运行在诸如 Linux、 BSD、 Solaris、 HP-UNIX 等系统上面，是一个完全免费的、开放源代码的 FTP 服务器软件。

2.ftp 配置

我们今天还是使用OKMX6ULL-s2开发板来举例。

开发板默认已经启动vsftpd服务，我们先看一下配置。

我们看到关于ftp的配置有4个文件，

root@fetmx6ull-s:/etc# more vsftpd.chroot_listrootroot@fetmx6ull-s:/etc#

可以看到，我们ftp默认使用的用户名为root，

root@fetmx6ull-s:/etc# more vsftpd.ftpusers# Users that are not allowed to login via ftprootbindaemonadmlpsyncshutdownhaltmailnewsuucpoperatorgamesnobodyroot@fetmx6ull-s:/etc# more vsftpd.user_list# vsftpd userlist# If userlist_deny=NO, only allow users in this file# If userlist_deny=YES (default), never allow users in this file, and# do not even prompt for a password.# Note that the default vsftpd pam config also checks /etc/vsftpd.ftpusers# for users that are denied.rootbindaemonadmlpsyncshutdownhaltmailnewsuucpoperatorgamesnobodyroot@fetmx6ull-s:/etc#root@fetmx6ull-s:/etc# more vsftpd.conf# Example config file /etc/vsftpd.conf## The default compiled in settings are fairly paranoid. This sample file# loosens things up a bit, to make the ftp daemon more usable.# Please see vsftpd.conf.5 for all compiled in defaults.## READ THIS: This example file is NOT an exhaustive list of vsftpd options.# Please read the vsftpd.conf.5 manual page to get a full idea of vsftpd's# capabilities.# run standalonelisten=YES# Allow anonymous FTP? (Beware - allowed by default if you comment this out).anonymous_enable=YES## Uncomment this to allow local users to log in.local_enable=YES## Uncomment this to enable any form of FTP write command.write_enable=YES## Default umask for local users is 077. You may wish to change this to 022,# if your users expect that (022 is used by most other ftpd's)local_umask=022## Uncomment this to allow the anonymous FTP user to upload files. This only# has an effect if the above global write enable is activated. Also, you will# obviously need to create a directory writable by the FTP user.#anon_upload_enable=YES## Uncomment this if you want the anonymous FTP user to be able to create# new directories.#anon_mkdir_write_enable=YES## Activate directory messages - messages given to remote users when they# go into a certain directory.dirmessage_enable=YES## Activate logging of uploads/downloads.xferlog_enable=YES## Make sure PORT transfer connections originate from port 20 (ftp-data).connect_from_port_20=YES## If you want, you can arrange for uploaded anonymous files to be owned by# a different user. Note! Using "root" for uploaded files is not# recommended!#chown_uploads=YES#chown_username=whoever## You may override where the log file goes if you like. The default is shown# below.#xferlog_file=/var/log/vsftpd.log## If you want, you can have your log file in standard ftpd xferlog formatxferlog_std_format=YES## You may change the default value for timing out an idle session.#idle_session_timeout=600## You may change the default value for timing out a data connection.#data_connection_timeout=120## It is recommended that you define on your system a unique user which the# ftp server can use as a totally isolated and unprivileged user.#nopriv_user=ftp## Enable this and the server will recognise asynchronous ABOR requests. Not# recommended for security (the code is non-trivial). Not enabling it,# however, may confuse older FTP clients.#async_abor_enable=YES## By default the server will pretend to allow ASCII mode but in fact ignore# the request. Turn on the below options to have the server actually do ASCII# mangling on files when in ASCII mode.# Beware that turning on ascii_download_enable enables malicious remote parties# to consume your I/O resources, by issuing the command "SIZE /big/file" in# ASCII mode.# These ASCII options are split into upload and download because you may wish# to enable ASCII uploads (to prevent uploaded scripts etc. from breaking),# without the DoS risk of SIZE and ASCII downloads. ASCII mangling should be# on the client anyway..#ascii_upload_enable=YES#ascii_download_enable=YES## You may fully customise the login banner string:#ftpd_banner=Welcome to blah FTP service.## You may specify a file of disallowed anonymous e-mail addresses. Apparently# useful for combatting certain DoS attacks.#deny_email_enable=YES# (default follows)#banned_email_file=/etc/vsftpd.banned_emails## You may specify an explicit list of local users to chroot() to their home# directory. If chroot_local_user is YES, then this list becomes a list of# users to NOT chroot().chroot_list_enable=YES# (default follows)chroot_list_file=/etc/vsftpd.chroot_list## You may activate the "-R" option to the builtin ls. This is disabled by# default to avoid remote users being able to cause excessive I/O on large# sites. However, some broken FTP clients such as "ncftp" and "mirror" assume# the presence of the "-R" option, so there is a strong case for enabling it.#ls_recurse_enable=YES## This string is the name of the PAM service vsftpd will use.pam_service_name=vsftpd## This option is examined if userlist_enable is activated. If you set this# setting to NO, then users will be denied login  unless  they are  explicitly# listed  in the file specified by userlist_file.  When login is denied, the# denial is issued before the user is asked for a password.userlist_deny=YES## If enabled, vsftpd will load a list of usernames, from the filename given by# userlist_file.  If a user tries to log in using  a  name in  this  file,  they# will be denied before they are asked for a password. This may be useful in# preventing cleartext passwords being transmitted. See also userlist_deny.userlist_enable=NO## If enabled,  vsftpd  will display directory listings with the time in your# local time zone. The default is to display GMT. The times returned by the# MDTM FTP command are also affected by this option.use_localtime=YES## If set to YES, local users will be (by default) placed in a chroot() jail in# their home directory after login.  Warning: This  option has  security # implications,  especially  if  the users have upload permission, or shell access.# Only enable if you know what you are doing.  Note that these security implications# are not vsftpd specific. They apply to all FTP daemons which offer to put# local  users in chroot() jails.chroot_local_user=YES#allow_writeable_chroot=YES#tcp_wrappers=YES

从以上三个文件中，我们可以看到（这里不分析具体的配置说明），可以使用root用户进行ftp的登录，这里对ftp的root账户没有指定口令，所以要使用默认的口令，

修改口令可以使用passwd来完成。

3.连接ftp服务器

我的开发板的地址是192.168.0.232

1）第一种方法使用windows的命令行模式。

我一般喜欢使用win10中的powershell，因为这个是跨平台的，可以支持linux命令；

可以看到，我们已经连接成功了，并且可以看到ftp的根目录是  家目录的地址。

PS C:\Users\Administrator> ftp 192.168.0.232连接到 192.168.0.232。220 (vsFTPd 3.0.3)200 Always in UTF8 mode.用户(192.168.0.232:(none)): root331 Please specify the password.密码:230 Login successful.ftp> ls200 PORT command successful. Consider using PASV.150 Here comes the directory listing.JL2-24.logUSBDrv.infaaauto.shcpu.logcpu1.loginfo.logmem.logmemtestermountdata.shnet.logrun.shstresssysinfo.shtemp.logtm.shtn226 Directory send OK.ftp: 收到 161 字节，用时 0.00秒 40.25千字节/秒。ftp>

从嵌入式系统下载文件

ftp> get auto.sh d:\auto.sh200 PORT command successful. Consider using PASV.150 Opening BINARY mode data connection for auto.sh (33 bytes).226 Transfer complete.ftp: 收到 33 字节，用时 0.00秒 33000.00千字节/秒。

上传文件到嵌入式系统中

ftp> put d:\auto.sh a.sh200 PORT command successful. Consider using PASV.150 Ok to send data.226 Transfer complete.ftp: 发送 33 字节，用时 0.01秒 2.20千字节/秒。ftp>

2）使用工具软件filezilla软件

输入正确的ip地址，用户名 和密码，登录

可以看到，已经登录成功了，并且列出了ftp服务器上的根目录的文件（实际就是家目录下的文件），我们可以对比一下

具体的这个上传下载旧更简单了。不需要在这里啰嗦了。

就写到这里了。欢迎评论，共同提高。。