系统环境：
$ cat /etc/redhat-release
CentOS Linux release 7.4.1708 (Core)
ftp 根目录 : /home/admin/upload
ftp 配置文件目录：/etc/vsftpd
ftp 虚拟用户权限配置文件目录：/etc/vsftpd/vsftp.conf
实现目标:
虚拟用户对自己的宿主目录有任何权限，且只能在自己宿主目录中操作
1、安装vsftpd和db_load加密工具
#要关闭selinux 和防火墙或者开启允许的端口，不然访问会有问题
sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config #修改配置文件
setenforce 0 #临时关闭
systemctl stop firewalld.service #关闭防火墙
yum install vsftpd db4-utils -y
2、创建本地用户[用于映射虚拟用户]
#建立ftp用户目录
mkdir -p /home/admin/
#创建用户
useradd -d /home/admin admin
更改权限和主组权限
chmod 755 /home/admin
chown vuser.root /home/admin
3、创建虚拟用户[用户和密码]文件---虚拟用户全部写在这个目录里面
vim /etc/vsftpd/.ftpuser
jin [用户名]
123456 [密码]
4、加密用户密码文件生成数据库文件
cd /etc/vsftpd
db_load -T -t hash -f ./.ftpuser ./.ftpuser.db
chmod 600 .ftpuser.db
5、创建PAM认证文件
auth sufficient /lib64/security/pam_userdb.so db=/etc/vsftpd/.ftpuser
account sufficient /lib64/security/pam_userdb.so db=/etc/vsftpd/.ftpuser
6、修改配置文件
vim /etc/vsftpd/vsftpd.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=YES
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
guest_enable=YES
guest_username=admin 映射的用户
pam_service_name=vsftpd
virtual_use_local_privs=YES
user_config_dir=/etc/vsftpd/.vconf 虚拟用户的配置目录
#
# 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
anon_upload_enable=NO
#
# Uncomment this if you want the anonymous FTP user to be able to create
# new directories.
#anon_mkdir_write_enable=YES
anon_mkdir_write_enable=NO
#
# 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/ftp/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.
# 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
chroot_local_user=YES
chroot_list_enable=NO
allow_writeable_chroot=YES
# (default follows)
#
# 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
tcp_wrappers=YES
pasv_enable=YES
pasv_min_port=20000
pasv_max_port=20080
pasv_promiscuous=YES
#指定虚拟用户的具体主路径
anonymous_enable=NO
#设定不允许匿名用户访问
write_enable=YES
#设定允许写操作
local_umask=022
#设定上传文件权限掩码
anon_upload_enable=NO
#设定不允许匿名用户上传
anon_mkdir_write_enable=NO
#设定不允许匿名用户建立目录
idle_session_timeout=600
#设定空闲连接超时时间
data_connection_timeout=120
#设定单次连续传输最大时间
#max_clients=10
#设定并发客户端访问个数
#max_per_ip=5
#设定单个客户端的最大线程数，这个配置主要来照顾Flashget、迅雷等多线程下载软件
#local_max_rate=50000
#设定该用户的最大传输速率，单位b/s
8、重启服务
systemctl restart vsftpd.service
9、验证登入
直接找一台机器： ftp 服务端ip 输入用户名和密码，就能够看到目录中的文件目录
$ cat /etc/redhat-release
CentOS Linux release 7.4.1708 (Core)
ftp 根目录 : /home/admin/upload
ftp 配置文件目录：/etc/vsftpd
ftp 虚拟用户权限配置文件目录：/etc/vsftpd/vsftp.conf
实现目标:
虚拟用户对自己的宿主目录有任何权限，且只能在自己宿主目录中操作
1、安装vsftpd和db_load加密工具
#要关闭selinux 和防火墙或者开启允许的端口，不然访问会有问题
sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config #修改配置文件
setenforce 0 #临时关闭
systemctl stop firewalld.service #关闭防火墙
yum install vsftpd db4-utils -y
2、创建本地用户[用于映射虚拟用户]
#建立ftp用户目录
mkdir -p /home/admin/
#创建用户
useradd -d /home/admin admin
更改权限和主组权限
chmod 755 /home/admin
chown vuser.root /home/admin
3、创建虚拟用户[用户和密码]文件---虚拟用户全部写在这个目录里面
vim /etc/vsftpd/.ftpuser
jin [用户名]
123456 [密码]
4、加密用户密码文件生成数据库文件
cd /etc/vsftpd
db_load -T -t hash -f ./.ftpuser ./.ftpuser.db
chmod 600 .ftpuser.db
5、创建PAM认证文件
vim /etc/pam.d/vsftpd
把里面原先有的全部注释掉，在添加下面的
account sufficient /lib64/security/pam_userdb.so db=/etc/vsftpd/.ftpuser
6、修改配置文件
vim /etc/vsftpd/vsftpd.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=YES
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
guest_enable=YES
guest_username=admin 映射的用户
pam_service_name=vsftpd
virtual_use_local_privs=YES
user_config_dir=/etc/vsftpd/.vconf 虚拟用户的配置目录
#
# 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
anon_upload_enable=NO
#
# Uncomment this if you want the anonymous FTP user to be able to create
# new directories.
#anon_mkdir_write_enable=YES
anon_mkdir_write_enable=NO
#
# 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/ftp/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.
# 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
chroot_local_user=YES
chroot_list_enable=NO
allow_writeable_chroot=YES
# (default follows)
#
# 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
tcp_wrappers=YES
pasv_enable=YES
pasv_min_port=20000
pasv_max_port=20080
pasv_promiscuous=YES
7、在配置虚拟用户的访问权限（这个目录名称和虚拟用户文件里面的用户要一样）
[root@Net-Hospital-01 .vconf]# pwd
/etc/vsftpd/.vconf
[root@Net-Hospital-01 .vconf]# ls
ftpuser--这个目录名称要和用户一样
#指定虚拟用户的具体主路径
anonymous_enable=NO
#设定不允许匿名用户访问
write_enable=YES
#设定允许写操作
local_umask=022
#设定上传文件权限掩码
anon_upload_enable=NO
#设定不允许匿名用户上传
anon_mkdir_write_enable=NO
#设定不允许匿名用户建立目录
idle_session_timeout=600
#设定空闲连接超时时间
data_connection_timeout=120
#设定单次连续传输最大时间
#max_clients=10
#设定并发客户端访问个数
#max_per_ip=5
#设定单个客户端的最大线程数，这个配置主要来照顾Flashget、迅雷等多线程下载软件
#local_max_rate=50000
#设定该用户的最大传输速率，单位b/s
8、重启服务
systemctl restart vsftpd.service
9、验证登入
直接找一台机器： ftp 服务端ip 输入用户名和密码，就能够看到目录中的文件目录