ubuntu ftp 服务器搭建及vsftpd.conf配置实例详解

一、ftp服务器搭建与简单配置

这个部分的教程还是很多的，参考两个即可：
如何在ubuntu中安装设置ftp服务器？
Ubuntu 14.04 FTP服务器–vsftpd的安装和配置

总结一下步骤吧：
1、安装

sudo apt-get install vsftpd

2、修改配置文件/etc/vsftpd.conf
根据具体的情况进行修改，去掉注释等，接下来会详细介绍。

3、重启vsftpd服务

sudo service vsftpd restart

然后查看服务是否成功开启

sudo service vsftpd status

如果看到active（running）就说明成功了，否则很可能是配置文件修改出错。
服务状态

4、登录测试
实际测试一下是否达到预想的功能。

二、实例详解ftp服务器配置

我们搭建ftp服务器想要实现以下特点：
1、user1用户作为本地最高级用户在ftp中几乎不受什么限制，可以访问全部目录，可以上传可以下载，可以删除，新建目录，新建文件。
2、user2用户作为作为本地用户，ftp登陆后限制在自己的主目录内（/home/user2），在其主目录下可以上传可以下载，可以删除，新建目录，新建文件。
3、匿名用户（其他任何人，不需要专门的密码就可以访问）限制在/home/ftp目录下，且只有下载权限。

如上的特点大概符合一般场景，本地用户中，管理员自然最大了，想干啥就干啥，其他本地用户就访问自己的目录就好啦，在自己的范围内想干啥就干啥，然后其他外来人员可以下载指定的资源，这样管理员可以共享一些东西供其他人下载，其他人只能下载，不能修改，所以也不能造成什么破坏。

好啦，照着这个目标，开始配置/etc/vsftpd.conf文件

允许匿名用户访问，并且对匿名用户的目录进行限制，限制到/home/ftp

anonymous_enable=YES
anon_root=/home/ftp

这里特别说明，/home/ftp目录，不能有w权限，这是一个只读的目录，否者会报错。修改权限可以使用

sudo chmod a-w /home/ftp

本地用户能够访问，且拥有写的权限

local_enable=YES
write_enable=YES

本地用户登录后限制在自己的主目录下，同时通过文件/etc/vsftpd.chroot_list来指定不用限制目录的用户（比如我们的user1不用限制目录，所以要在该文件下写上user1），同时允许用户对自己的主目录进行修改。

chroot_local_user=YES
chroot_list_enable=YES
chroot_list_file=/etc/vsftpd.chroot_list
allow_writeable_chroot=YES

启用用户列表，不在列表中的用户禁止登陆（所以我们要在etc/allowed_users中写上user1，user2，anonymous，ftp，其中最后两个都表示匿名登录）

user_list_enable=YES
user_list_deny=NO
userlist_file=/etc/allowed_users

这个是经验项，配置了据说可以避免一些错误，参考文献中有介绍。
seccomp_sandbox=NO

到此，还注意到，里面涉及到了两个文件，一个是/etc/vsftpd.chroot_list，一个是/etc/allowed_users，我们保存了之后需要自己手动创建这两个文件，

sudo touch /etc/vsftpd.chroot_list
sudo touch /etc/allowed_users

然后在/etc/vsftpd.chroot_list中的用户不被限制目录，这个例子中我们要写入user1，/etc/allowed_users中要写入允许访问服务器的用户，这里就是user1，user2，还有匿名用户anonymous，ftp，注意写的时候每行只写一个用户名。

保存好了就重启服务，验证即可。

最后，一点注意，匿名用户只能访问/home/ftp目录，那么里面的文件需要超级用户复制进去，并且所有文件需要有可读的权限，否者其他用户下载会出错。

贴一下配置文件的整体代码，方便大家比对。

# 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=YES
anon_root=/home/ftp
#
# 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 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 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=vsftpd
#
# 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

userlist_enable=YES
userlist_deny=NO
userlist_file=/etc/allowed_users
#local_root=/home
seccomp_sandbox=NO
allow_writeable_chroot=YES
#
# Uncomment this to indicate that vsftpd use a utf8 filesystem.
#utf8_filesystem=YES