centos7 vsftp被动

ftp有两种工作模式，主动模式（port）和被动模式（passive）

主动模式：主动模式相对有利于服务端，在客户端访问服务端的21端口（默认端口不变的情况下）确认要进行ftp数据传输后，是客户端开放1024以上的随机端口给服务端去访问进行数据传输，对于客户端的网络管理是较不便的。

被动模式：被动模式相对有利于客户端，在客户端发送pasv信号通过21端口传送给服务端口，服务端会响应并开放vsftp.conf文件中配置的pasv_min_port和pasv_max_port范围内的随机端口，对于服务端防火墙等配置有要求。

 

一、准备工作

1、检查服务器有没有安装过vsftp，然后检查本地yum库里有没有安装包。

[root@docker ~]# rpm -qa | grep vsftpd
[root@docker ~]# which vsftpd
/usr/bin/which: no vsftpd in (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin)
上面说明服务器还没有安装ftp server，可以检查服务器有没有这个安装包了
[root@docker ~]# yum list | grep vsftpd
vsftpd.x86_64                                        3.0.3-28.el8                                      AppStream

2、关闭selinux

 

二、开始安装

1、执行yum安装语句

yum -y isntall vsftpd

 

 2、启动相关程序

[root@docker ~]# systemctl start vsftpd     --启动ftp
[root@docker ~]# systemctl enable vsftpd    --将ftp加入到开机自启动
Created symlink /etc/systemd/system/multi-user.target.wants/vsftpd.service → /usr/lib/systemd/system/vsftpd.service.
[root@docker ~]# netstat -antup | grep ftp   --检查ftp服务是否在监听
tcp6       0      0 :::21                   :::*                    LISTEN      32333/vsftpd

 

三、vsftp的相关配置解析

[root@docker ~]# cd /etc/vsftpd/
[root@docker vsftpd]# ls
ftpusers  user_list  vsftpd.conf  vsftpd_conf_migrate.sh

1、ftpusers   即ftp黑名单用户，只要在这个文件内的用户，均无法使用ftp服务。

2、user_list 是和vsftpd.conf中的userlist_enable和userlist_deny两个配置项紧密相关的，它可以有效，也可以无效，有效时它可以是一个黑名单，也可以是一个白名单！

(1)userlist_enable和userlist_deny两个选项联合起来针对的是：本地全体用户（除去ftpusers中的用户）和出现在user_list文件中的用户以及不在在user_list文件中的用户这三类用户集合进行的设置。
(2)当且仅当userlist_enable=YES时：userlist_deny项的配置才有效，user_list文件才会被使用；当其为NO时，无论userlist_deny项为何值都是无效的，本地全体用户（除去ftpusers中的用户）都可以登入FTP
(3)当userlist_enable=YES时，userlist_deny=YES时：user_list是一个黑名单，即：所有出现在名单中的用户都会被拒绝登入；
(4)当userlist_enable=YES时，userlist_deny=NO时：user_list是一个白名单，即：只有出现在名单中的用户才会被准许登入(user_list之外的用户都被拒绝登入)；另外需要特别提醒的是：使用白名单后，匿名用户将无法登入！除非显式在user_list中加入一行：anonymous

 

 

 

3、配置vsftp.conf

# Example config file /etc/vsftpd/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.
#
# Allow anonymous FTP? (Beware - allowed by default if you comment this out).
anonymous_enable=NO   ---是否允许匿名登录 
#
# Uncomment this to allow local users to log in.
# When SELinux is enforcing check for SE bool ftp_home_dir
local_enable=YES     ----是否允许本地用户登录FTP服务器
#
# Uncomment this to enable any form of FTP write command.
write_enable=YES     ----是否对登录用户开启写权限。属全局性设置。
#
# 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    --目录和文件被创建时得到的初始权限，022即目录权限755，文件权限644
#
# 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.
# When SELinux is enforcing check for SE bool allow_ftpd_anon_write, allow_ftpd_full_access
#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  --当用户进入某个目录时，会显示该目录需要注意的内容
#
# Activate logging of uploads/downloads.
xferlog_enable=YES --当设定为 YES 时，使用者上传与下载文件都会被纪录起来。
#
# Make sure PORT transfer connections originate from port 20 (ftp-data).
connect_from_port_20=YES  --默认的数据传输端口为20
#
# 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/xferlog
#
# 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. The vsftpd.conf(5) man page explains
# the behaviour when these options are disabled.
# 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 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().
# (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   ---指定用户列表文件中的用户允许切换到上级目录
chroot_list_enable=YES  --是否启用chroot_list_file配置指定的用户列表
# (default follows)
chroot_list_file=/etc/vsftpd/chroot_list   ---默认该文件不存在，需手动创建，主要是在
前两项均为YES时，配置可以cd到上级目录的用户。
# 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
#
# When "listen" directive is enabled, vsftpd runs in standalone mode and
# listens on IPv4 sockets. This directive cannot be used in conjunction
# with the listen_ipv6 directive.
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.
# Make sure, that one of the listen options is commented !!
listen_ipv6=YES

pam_service_name=vsftpd
userlist_enable=YES
userlist_deny=NO    -----只有添加到user_list文件的用户才能访问

allow_writeable_chroot=YES  --对vsftpd有用，否则因home目录权限而无法登录

  pasv_enable=YES

  pasv_min_port=50000

  pasv_max_port=60000   

listen_port=2121 --修改默认端口号

  注意：修改端口还需编辑/etc/services文件，修改ftp配置，将21改成2121

 

  

重启vsftpd

[root@docker vsftpd]# systemctl restart vsftpd

测试端口是否已变更。

[root@docker vsftpd]# netstat -antup | grep vsftpd
tcp6       0      0 :::2121                 :::*                    LISTEN      33275/vsftpd

 

四、添加ftp用户

一般添加ftp服务，都是要存文件之类的，可以指定一个挂在了较大磁盘空间的目录做为ftp用户的家目录。

注意：如果ftp目录是提前创建的，创建完用户后，记得把ftp目录的属组和用户改成ftp用户，如果是没有提前创建，则会自动创建，并且会默认归属是创建的用户和用户组
[root@docker ~]# useradd -d /data -s /sbin/nologin -g ftptest ahftp
useradd: warning: the home directory already exists.
Not copying any file from skel directory into it.
[root@docker ~]# cat /etc/passwd

   ahftp:x:1001:1001::/data:/sbin/nologin

设置密码

passwd ahftp

设置ftp用户nologin后，需要在shell内添加该项。

输入 cat /etc/pam.d/vsftpd | fgrep pam_shell 后显示为:

auth       required     pam_shells.so

看到以上结果后,再次输入 :echo "/sbin/nologin" >> /etc/shells

 修改用户目录

usermod -d /test test //更改用户test的主目录为/test

 

五、防火墙策略

[root@docker data]# firewall-cmd --permanent --add-port=2121/tcp
success
[root@docker data]# firewall-cmd --permanent --add-port=50000-60000/tcp
success
[root@docker data]# firewall-cmd --reload
success
[root@docker data]# firewall-cmd --list-all
public (active)
  target: default
  icmp-block-inversion: no
  interfaces: ens33
  sources: 
  services: cockpit dhcpv6-client ssh
  ports: 10086/tcp 2121/tcp 50000-60000/tcp
  protocols: 
  masquerade: no
  forward-ports: 
  source-ports: 
  icmp-blocks: 
  rich rules:

六、测试

建议先本地测试。

一些命令
lcd  【目录】 指定下载的文件目的路径或上传的源路径
!ls               显示当前ftp下的文件
ftp [地址]      登录ftp服务
put  【文件名】指定上传的文件进行上传
mput [*.*或者*.后缀] 批量上传文件
get 和mget用法与put类似

七、我的测试文件参考

# Example config file /etc/vsftpd/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.
#
# Allow anonymous FTP? (Beware - allowed by default if you comment this out).
anonymous_enable=NO
#
# Uncomment this to allow local users to log in.
# When SELinux is enforcing check for SE bool ftp_home_dir
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.
# When SELinux is enforcing check for SE bool allow_ftpd_anon_write, allow_ftpd_full_access
#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/xferlog
#
# 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. The vsftpd.conf(5) man page explains
# the behaviour when these options are disabled.
# 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 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().
# (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
#
# When "listen" directive is enabled, vsftpd runs in standalone mode and
# listens on IPv4 sockets. This directive cannot be used in conjunction
# with the listen_ipv6 directive.
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.
# Make sure, that one of the listen options is commented !!
listen_ipv6=YES

pam_service_name=vsftpd
userlist_deny=NO
userlist_enable=YES
#tcp_wrappers=YES
allow_writeable_chroot=YES
pasv_enable=YES
pasv_min_port=50000
pasv_max_port=50010
listen_port=2121