本人系菜鸟一个，前一段突发奇想做了以下的试验，现在问题解决了，把解决的方法总结一下，谨供参考，希望能给像我一样的菜鸟有所帮助。第一次写总结，总有如履薄冰，如临深渊的感觉，生怕误导别人。其中一定会有不妥或是错误，或者如果大家有什么更好的方法，希望大家提出来一起讨论。
解决过程中不少兄弟热情帮助尤其是wolfg斑竹的大力支持，十分感谢。

说明：在FC3上用vsftp实FTP服务。由于一些网段的用户为内部成员，不会对服务器造成危害。为了减少麻烦，更好地实现资源共享，现在想给他们的网段（本例中以10.0.1.*为例）的用户以自由上传下载的权利。

涉及的配置文件一共有四个：
vsftpd.conf
hosts.allow
/etc/vsftpd/local.class
/etc/vsftpd/other.class

内容：

hosts.allow
代码:
#
# hosts.allow   This file describes the names of the hosts which are
#      allowed to use the local INET services, as decided
#      by the '/usr/sbin/tcpd' server.
vsftpd: 10.0.1.* : setenv VSFTPD_LOAD_CONF /etc/vsftpd/local.class
vsftpd: ALL : setenv VSFTPD_LOAD_CONF /etc/vsftpd/other.class


/etc/vsftpd/local.class
代码:
write_enable=YES
anon_upload_enable=YES
anon_mkdir_write_enable=YES


/etc/vsftpd/other.class
代码:
write_enable=NO
anon_upload_enable=NO
anon_mkdir_write_enable=NO


vsftpd.conf
代码:
# 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
#
# Uncomment this to allow local users to log in.
# 不允许本地用户上传下载,即只允许基于ip的认证
#local_enable=YES
#
# Uncomment this to enable any form of FTP write command.
# 在ftpd中的local.class和other.class文件中有write_enable=YES项
#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
#
# 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
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=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().
#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
Anon_umask=022
pam_service_name=vsftpd
userlist_enable=YES
#下面一行是我加的
userlist_deny=YES
#enable for standalone mode
listen=YES
tcp_wrappers=YES


说明一下：
首先设置vsftpd.conf中tcp_wrappers=YES（一般的默认设置都是YES）。
当有用户访问时，则会自动查看hosts.allow的配置，而在根据hosts.allow中的语句，
系统会根据客户的IP跳转到不同的文件去，按照那里的设置工作。
在/etc/vsftpd/local.class中设置10.0.1.*网段的用户可以自由上传下载。
在/etc/vsftpd/other.class中设置其他用户只有下载的权限。
就是这么简单。不过有一点必须说明：那就是目录和文件的权限问题。
首先，设置你想让匿名用户上传的目录的可写权限
再一个在
vsftpd.conf中要加上
anon_umask=022
这一行是给匿名用户上传的文件添加可读的权限。你可以测试一下，匿名用户上传的文件的权限是600，即上传上去了却没有可读权限,下载不了！
Over！Good luck!