Ubuntu 14.04 下FTP服务器的搭建--锁定用户目录，解决vsftpd: refusing to run with writable root inside chroot()
FTP服务器的搭建，我要实现的需求是：
不允许匿名访问，因为我的机器不想让谁都能登录上来，随便获取文件，
需要锁定一个目录，因为在家里，我需要给媳妇下载一些电影 韩剧之类的东西，媳妇会来我机器下载，但是我不想让他随意操作我的东西。
万一删除我的配置文件，我就惨了（吐槽一下韩剧：媳妇问我，你都没看过韩剧怎么知道它不好看呢，我说：我没吃过屎 但是知道它一定不好吃！）
另外，需要本机也能访问，因为我要做一些关于FTP的测试。
不单独建立FTP用户，FTP也使用ubuntu桌面的用户进行登录和操作，
我还不希望FTP开始启动。
好了 我们开始安装，很简单。
sudo apt-get install vsftpd
30秒内估计就能安装完。
下面开始配置：
首先备份配置文件。
linuxidc@ubuntu:/etc/init$ cd /etc/
linuxidc@ubuntu:/etc$ sudo cp vsftpd.conf vsftpd.conf.old
接下来就是开始配置了，
咱们就针对需求来：
1. 不允许匿名访问，因为我的机器不想让谁都能登录上来，随便获取文件，
配置如下：
23 anonymous_enable=NO
2.需要锁定一个目录，因为在家里，我需要给媳妇下载一些电影 韩剧之类的东西，
媳妇会来我机器下载，但是我不想让他随意操作我的东西。
万一删除我的配置文件，我就惨了
配置如下：
152 local_root=/home/linuxidc/公共的/FTP共享文件
备注：[FTP共享文件] 这个文件夹是我新建出来的
另外，需要本机也能访问，因为我要做一些关于FTP的测试。
配置如下：
26 local_enable=YES
不单独建立FTP用户，FTP也使用ubuntu桌面的用户进行登录和操作，
配置如下：
120 #chroot_local_user=YES
121 chroot_list_enable=YES
122 # (default follows)
123 chroot_list_file=/etc/vsftpd.chroot_list
这里需要/etc/vsftpd.chroot_list 这个文件，如果没有请新建：
sudo gedit /etc/vsftpd.chroot_list
内容如下（例如我桌面的用户名为linuxidc）：
duoduo
其实就是把你的用户名写进去
我还不希望FTP开始启动。 一会单独说！
贴出我的配置文件。
# 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=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=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 linuxidc's 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 # This option specifies the location of the RSA key to use for SSL # encrypted connections. rsa_private_key_file=/etc/ssl/private/ssl-cert-snakeoil.key # local_root=/home/linuxidc/公共的/FTP共享文件
现在可以重启FTP了。
linuxidc@ubuntu:/etc$ sudo service vsftpd restart vsftpd stop/waiting vsftpd start/running, process 303
OK 看到这些 证明配置文件没有问题，FTP启动了
下面直接访问FTP 看看：
linuxidc@ubuntu:/etc$ ftp 127.0.0.1 Connected to 127.0.0.1. Welcome to linuxidc's FTP service. Name (127.0.0.1:linuxidc): duoduo Please specify the password. Password: OOPS: vsftpd: refusing to run with writable root inside chroot() Login failed. Service not available, remote server has closed connection ftp>
居然报了一个500的错误 vsftpd: refusing to run with writable root inside chroot()
。其实这里是需要特殊说明的，原因出在这里
120 #chroot_local_user=YES
121 chroot_list_enable=YES
122 # (default follows)
123 chroot_list_file=/etc/vsftpd.chroot_list
我们用
chroot_list_enable=YES 和 chroot_list_file=/etc/vsftpd.chroot_list配合使用，使得只有在vsftpd.chroot_list中配置的用户才能登录FTP。
对于这要的配置有一个特殊的要求，就是vsftpd.chroot_list里面配置的用户，对于前面local_root配置的目录不能有写的权限！
也就是/home/linuxidc/公共的/FTP共享文件 这个文件夹 对于linuxidc这个用户不能有写的权限，
我们为了额操作方便可以这么做：
sudo chown -R root:root /home/linuxidc/公共的/FTP共享文件/
这样，linuxidc这个用户对于/home/linuxidc/公共的/FTP共享文件没有写权限了，
现在重启FTP 重新登录看看：
linuxidc@ubuntu:/etc$ ftp 127.0.0.1 Connected to 127.0.0.1. Welcome to linuxidc's FTP service. Name (127.0.0.1:linuxidc): duoduo Please specify the password. Password: Login successful. Remote system type is UNIX. Using binary mode to transfer files. ftp>
OK FTP 好了 可以登录了
但是我刚才 sudo chown -R root:root /home/linuxidc/公共的/FTP共享文件/ 这个操作 还带来了一个麻烦。就是FTP共享文件在我桌面登录时，不能任意复制粘贴操作文件了，但是我还要必须保持linuxidc用户对[FTP共享文件] 这个文件夹不可写。这该怎么办呢？
其实很简单，
cd /home/linuxidc/公共的/FTP共享文件 sudo mkdir FTPFILES sudo chown -R linuxidc:duoduo FTPFILES
这样 就保持了 FTP共享文件 文件夹linuxidc用户不可写，但duoduo用户用可以在桌面登录时任意操作文件了，只不过此时的随意范围在FTPFILES文件夹范围呢了。
这样基本FTP服务基本搭建完成了。
对了 忘记了一点。就是不让FTP服务开机启动。操作如下：
linuxidc@ubuntu:/etc/init$ cd /etc/init/ linuxidc@ubuntu:/etc/init$ sudo cp vsftpd.conf vsftpd.conf.old
编辑配置文件
sudo gedit /etc/init/vsftpd.conf
将#start on runlevel [2345] or net-device-up IFACE!=lo 修改为start on runlevel [345] 如下：
#start on runlevel [2345] or net-device-up IFACE!=lo start on runlevel [345] stop on runlevel [!2345]
这次重启FTP 重启系统 彻底完成。
这里建议大家查一下：chroot_local_user chroot_list_enable=YES chroot_list_file=/etc/vsftpd.chroot_list 相关的资料，这里面灵活性配置很高的。
