Vsftpd

vsftpd，ftp服务端

stand alone和super daemon

stand alone指的是一直运行vsftpd，占用资源，提供ftp服务。super daemon指的是有需要时由xinted启动vsftpd服务。如果服务器不是那种长期开ftp，提供大量的上传下载服务的话，会选择后者。

安装

安装

sudo apt-get install vsftpd

查看是否打开21端口

qii@ubuntu:~$ sudo netstat -tulnp| grep 21
tcp        0      0 0.0.0.0:21              0.0.0.0:*               LISTEN      15601/vsftpd    

登录

ftp localhost

输入Ubuntu的用户名、密码登录

ls

会显示home目录的文件

文件结构

匿名用户根路径

/srv/ftp

配置文件

/etc/vsftpd.conf

查阅配置文件详细信息

man 5 vsftpd.conf

设定log保存位置，默认如下

xferlog_file=/var/log/vsftpd.log

运行

standalone

最普遍的方式

sudo service vsftpd start

super daemon

需要修改vsftpd.conf

listen=NO

这里若不改成NO，会出现下列错误

500 OOPS: could not bind listening IPv4 socket

安装xinetd

sudo apt-get install xinetd

sudo vi /etc/xinetd.conf

service ftp
{
        socket_type             = stream
        wait                    = no
        user                    = root
        server                  = /usr/sbin/vsftpd
        log_on_success          += DURATION USERID
        log_on_failure          += USERID
        nice                    = 10
        disable                 = no
}

停止vsftpd，启动xinetd

sudo service vsftpd stop

sudo service xinetd start

查看端口

qii@ubuntu:~$ sudo netstat -tulnp| grep 21
tcp        0      0 0.0.0.0:21              0.0.0.0:*               LISTEN      16787/xinetd  

/etc/vsftpd.conf

# Example config file /etc/vsftpd.conf

# Run standalone?  vsftpd can run either from an inetd or as a standalone
# daemon started from an initscript.
listen=YES
#
# Run standalone with IPv6?
# Like the listen parameter, except vsftpd will listen on an IPv6 socket
# instead of an IPv4 one. This parameter and the listen parameter are mutually
# exclusive.
#listen_ipv6=YES
#
# Allow anonymous FTP? (Disabled by default)
anonymous_enable=NO
#
# Uncomment this to allow local users to log in.
local_enable=NO
#
# 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().
#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
#
# Debian customization
#
# Some of vsftpd's settings don't fit the Debian filesystem layout by
# default.  These settings are more Debian-friendly.
#
# 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/private/vsftpd.pem

匿名用户

先备份

sudo cp /etc/vsftpd.conf /etc/vsftpd.conf.old

打开

sudo vi /etc/vsftpd.conf

允许匿名访问

# Allow anonymous FTP? (Disabled by default)
anonymous_enable=YES

允许匿名上传

anon_upload_enable=YES

认证FTP配置

设定vsftp认证系统用户，并允许他们上传文件，编辑 /etc/vsftpd.conf：

local_enable=YES
write_enable=YES

重启vsftp

sudo service vsftpd restart

系统用户登录ftp便进入他们的home目录

Chroot

限制所有

限制登录用户访问其他目录，改之前登录显示的路径比如是 /home/qii ，改之后则是 /。

chroot_local_user=YES

开放所有，限制特定

可指定一组用户限制

chroot_local_user=NO
chroot_list_enable=YES
chroot_list_file=/etc/vsftpd.chroot_list

随后创建列表

sudo vi  /etc/vsftpd.chroot_list

一行一个用户名 重启vsftp

sudo service vsftpd restart

限制所有，开放特定

上面的规则是限制 /etc/vsftpd.chroot_list 中的用户，反过来限制一切，只解禁 /etc/vsftpd.chroot_list 的用户。这样：

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

账号登录

/etc/ftpusers文件

该文件内的用户一律禁止ftp连接，默认列表包括了root, daemon, nobody等。需要禁止某个用户，添加进来便是。

这个文件是由PAM模块的 /etc/pam.d/vsftpd 指定的

qii@ubuntu:~$ sudo cat /etc/pam.d/vsftpd
# Standard behaviour for ftpd(8).
auth    required        pam_listfile.so item=user sense=deny file=/etc/ftpusers onerr=succeed

# Note: vsftpd handles anonymous logins on its own. Do not enable pam_ftp.so.

# Standard pam includes
@include common-account
@include common-session
@include common-auth
auth    required        pam_shells.so

userlist_file 文件

vsftpd自订的列表，跟/etc/ftpusers类似，具体文件名和路径是由用户自己指定的。这边设成 /etc/vsftpd.user_list

添加配置文件字段：

userlist_enable=YES
userlist_deny=YES
userlist_file=/etc/vsftpd.user_list

限制一切，开放特定

上述2个方法都是限制列表文件中的用户，如果要反过来，限制一切用户登录，只允许列表文件中的用户，用 userlist_file，这样：

userlist_enable=YES
userlist_deny=NO
userlist_file=/etc/vsftpd.user_list

root登录

之所以限制root这类账号登录就是托上面几个文件，要是你非要用系统账号登录，如上所述，将列表文件中的特定用户名删除便是。

限制

限制连接数

前者为服务器最大支持连接数，后者为每个ip允许最多连接数。

max_clients=数字
max_per_ip=数字

错误提示分别是

qii@ubuntu:~$ ftp localhost 
Connected to localhost.
421 There are too many connected users, please try later.

qii@ubuntu:~$ ftp localhost 
Connected to localhost.
421 There are too many connections from your internet address.

限制下载速度

单位是字节，所以需要换算。比如我想让匿名用户和vsFTP上的用户都以80KB下载，所以这个数字应该是1024x80=81920

anon_max_rate=数字 #匿名用户下载速度
local_max_rate=数字 #普通用户下载速度

Super daemon限制

以上都是stand alone模式的做法，super daemon这样做：

service ftp
{
        socket_type             = stream
        wait                    = no
        user                    = root
        server                  = /usr/sbin/vsftpd
        server_args             = /etc/vsftpd.conf 
        log_on_success          += DURATION USERID
        log_on_failure          += USERID
        nice                    = 10
        disable                 = no
        per_source              = 5    限制单个IP连接数
        instances               = 200  限制服务器最多连接数
}

欢迎信息

dirmessage_enable=YES

然后编辑各用户home目录下的.message

vi .message

qii@ubuntu:~$ cat .message 
欢迎来到vsftpd

qii@ubuntu:~$ ftp localhost 
Connected to localhost.
220 (vsFTPd 2.2.2)
Name (localhost:qii): qii
331 Please specify the password.
Password:
230-欢迎来到vsftpd
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> 

若是匿名用户，就放到

/var/ftp

虚拟路径

比如我的ftp的默认目录是/srv/ftp，我想把/mnt/LinG/WinSoft文件夹，映射到/srv/ftp目录中，我就如下操作 命令：

#mount --bind [原有的目录] [新目录]

先创建文件夹

sudo mkdir /srv/ftp/WinSoft

执行mount命令

sudo mount --bind /mnt/LinG/WinSoft /srv/ftp/WinSoft