前言

网络操作系统的实验，做这个的时候心态大崩，各种弱智问题出现，差点没磕死在桌上！顺带一句，垃圾inode，禁我虚拟机网卡。。。。

实验准备

ubuntu16.04 win7各一台，两个主机需要建立一个局域网，vm很容易实现这个事，ubuntu还需要外网网卡

实验开始

安装vsftpd

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sudo apt-get install vsftpd

修改/etc/vsftpd.conf文件

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sudo vim /etc/vsftpd.conf

修改内容如下：

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# 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 standalone?  vsftpd can run either from an inetd or as a standalone
# daemon started from an initscript.
listen=NO
#
# This directive enables listening on IPv6 sockets. By default, listening
# on the IPv6 "any" address (::) will accept connections from both IPv6
# and IPv4 clients. It is not necessary to listen on *both* IPv4 and IPv6
# sockets. If you want that (perhaps because you want to listen on specific
# addresses) then you must run two copies of vsftpd with two configuration
# files.
listen_ipv6=YES
#
# Allow anonymous FTP? (Disabled by default).
anonymous_enable=NO
#
# 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
#
# 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
#
# 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 format.
# Note that the default log file location is /var/log/xferlog in this case.
xferlog_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=ftpsecure
#
# 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 on some FTP servers, ASCII support allows a denial of service
# attack (DoS) via the command "SIZE /big/file" in ASCII mode. vsftpd
# predicted this attack and has always been safe, reporting the size of the
# raw file.
# ASCII mangling is a horrible feature of the protocol.
#ascii_upload_enable=YES
#ascii_download_enable=YES
#
# You may fully customise the login banner string:
ftpd_banner=Welcome to blash 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 restrict local users to their home directories.  See the FAQ for
# the possible risks in this before using chroot_local_user or
# chroot_list_enable below.
#chroot_local_user=YES
#
# 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().
# (Warning! chroot'ing can be very dangerous. If using chroot, make sure that
# the user does not have write access to the top level directory within the
# chroot)
chroot_local_user=YES
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
#
# Customization
#
# Some of vsftpd's settings don't fit the filesystem layout by
# default.
#
# This option should be the name of a directory which is empty.  Also, the
# directory should not be writable by the ftp user. This directory is used
# as a secure chroot() jail at times vsftpd does not require filesystem
# access.
secure_chroot_dir=/var/run/vsftpd/empty
#
# This string is the name of the PAM service vsftpd will use.
pam_service_name=ftp
#
# This option specifies the location of the RSA certificate to use for SSL
# encrypted connections.
rsa_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
rsa_private_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
ssl_enable=NO

#
# Uncomment this to indicate that vsftpd use a utf8 filesystem.
utf8_filesystem=YES

allow_writeable_chroot=YES

对于上面的文件解释一下：

  • listen=NO 是否开启监听ipv4和ipv6数据
  • anonymous_enable=NO 拒绝匿名登陆
  • write_able=YES 设置可以上传文件，这个设置可以看个人的需要
  • xferlog_enable=YES 开启日志记录
  • xferlog_file=/var/log/vsftpd.log 设置日志文件路径
  • xferlog_std_format=YES 设置日志格式为标准输出
  • connetct_from_port_20=YES 绑定20端口
  • ftpd_banner=welcome to FTP service. 欢迎语句，在使用shell时可以看到
  • chroot_local_user=YES
  • chroot_list_enable=YES
  • chroot_list_file=/etc/vsftpd.chroot_list 这三个配置实现的功能是：用户被限制在自己的主目录下。用户名单来源于/etc/vsftpd.chroot_list
  • pam_service_name=ftp 原配置中为vsftpd，ubuntu用户需要更改成ftp
  • utf8_filesystem=YES 编码统一为utf8编码，可以识别中文，防止乱码

创建用户组

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mkdir /home/username //
sudo useradd -d /home/username -m username -g ftp //在文件夹中创建用户名
sudo passwd username
//输入用户密码
mkdir /home/username/pub
chmod 777 -R /home/username/pub //新建一个pub目录用于存放文件，并赋予全部访问权限
usermod -s /sbin/nologin username //限制用户username只能通过ftp登陆，而不能直接登陆服务器

将创建的用户加入白名单

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sudo vim /etc/vsftp.chroot_list

然后重启ftp服务

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sudo service vsftpd restart

测试

首先在命令行内测试：

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ftp localhost

查看文件夹内文件

可以看见刚刚创建的共享文件夹pub

打开win7从资源管理器上进行登陆 ftp://192.168.112.129

输入账号密码即可登陆

在服务器端浏览器中输入ftp://localhost 登陆本地账户的账号密码：

在客户端浏览器输入ftp://192.168.112.129 登陆账号同样可以进行查看文件

总结

若在测试阶段，发现root用户登陆不了，即出现下面这种报错：

是因为root用户默认在ftp的黑名单中，这时我们只需要改变/etc/ftpusers中root注释掉就行

然后重启一下ftp服务,即可成功登陆

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sudo service vsftpd restart

若出现这种情况，则是因为chroot不可写

在配置文件/etc/vsftpd.conf中结尾加入一行 

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allow_writeable=YES

然后重启服务即可解决问题

参考链接：
https://blog.csdn.net/qq_33279781/article/details/73607466
https://blog.csdn.net/timothy93bp/article/details/77527531
https://blog.csdn.net/bluishglc/article/details/42398811