RedHat AS 4 下架设FTP服务器

 

    实验室刚买的IBM服务器上所装的RedHat  AS 4 默认没有安装vsftp,所以只能自己动手装了。没有到网上去下载,找到安装盘的ISO镜像disc1,在里面搜索vsftp*即可找到vsftpd-2.0.1-5.i386.rpm。将其放到系统的某个目录中(我放到home下),然后cd到该目录下,执行: " rpm  -ivh vsftpd-2.0.1-5.i386.rpm "。安装完成。接下来打开ect/vsftpd/vsftpd.conf文件,编辑里面的内容(蓝色部分是重点关注的)如下:
# 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          //不允许匿名登录
#
# 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           //写权限
#
# 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            //允许匿名用户上传,前提是上面的写权限打开
anon_other_write_enable=NO
#
# 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            //端口号
#
# 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
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 turning on ascii_download_enable enables malicious remote parties
# to consume your I/O resources, by issuing the command "SIZE /big/file" in
# ASCII mode.
# These ASCII options are split into upload and download because you may wish
# to enable ASCII uploads (to prevent uploaded scripts etc. from breaking),
# without the DoS risk of SIZE and ASCII downloads. ASCII mangling should be
# on the client anyway..
#ascii_upload_enable=YES
#ascii_download_enable=YES
#
# You may fully customise the login banner string:
ftpd_banner=欢迎访问本实验室~         //欢迎用语
#
# 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().
#chroot_local_user=YES                  //chroot即将用户限制在对应该用户的根目录
#chroot_list_enable=YES                 //只对下面chroot_list_file中的用户作chroot限制,如果对所用用户都作chroot限制,则不需要该项
# (default follows)
#chroot_list_file=/etc/vsftpd.chroot_list       //需要chroot限制的用户,和chroot_list_enable一起使用
#
# 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
pam_service_name=vsftpd
userlist_enable=YES
#userlist_deny=YES
#userlist_file=/etc/vsftpd/chroot_list
#enable for standalone mode
listen=YES
tcp_wrappers=YES
    保存后,FTP服务器设置完毕,重启Vsftpd :" /sbin/service vsftpd restart ",未被注释掉的即是可配置项,可根据自己的需要作相应设置。
    以上的配置不允许匿名登陆的,那么我介绍一下如何添加帐户,以及帐户的访问权限。
    添加用户
     " adduser –d          /任何目录 –g      ftp      –s      /sbin/nologin  用户名 "
    设置密码:passwd 用户名
    输入密码两次。
         
    创建成功后,在上面设置的目录下会自动创建一个与用户名同名的文件夹,这个用户只能访问该文件夹,可进行下载,上传,删除等操作。
温馨提示:在 /usr/share/doc 下面有系统中所有软件包的文档。 可以查看 /usr/share/doc/vsftpd* 目录下的FAQ,会对配置有所帮助。
      
附加管理问题:
  
1. 创建多个用户
还可以创建多个用户,每个用户的访问权限可以单独设定:
vsftpd.conf中加入 :
guest_username=virtual_user (virtual_user为所有用户所在的目录,如/home/ftp)
user_config_dir=/etc/vsftpd_user_config (该目录需要手动创建)
user_sub_token=$USER


/etc/vsftpd_user_config目录下为每个用户建一个配置文件,文件名与用户名相同,内容中必须有
local_root=/home/ftp/$USER
2. 将用户限制在其对应的家目录(即:chroot)中:
          有两种设置chroot的方法:
(1)设置对所有的本地用户执行chroot(即活动范围限制在自家目录)只要将chroot_local_user的值设 为YES即可, 即:

chroot_local_user=YES

(2)设置指定的用户执行chroot需要如下的设置:

chroot_local_user=NO
chroot_list_enable=YES (默认的)
chroot_list_file= /etc/vsftpd.chroot_list

这样,只有/etc/vsftpd.chroot_list文件中指定的用户才执行chroot。
注意 :上面所提及的文件/etc/vsftpd.chroot_list和下面将要提及的文件 /etc/vsftpd.user_list的格式要求均为每个 用户名占一行。
3. 删除用户:
userdel 用户名
4. 系统自动启动
运行:chkconfig vsftpd on