ก๊วนซอฟท์แวร์ </softganz> SoftGang (Gang Software)

เก็บไว้ก่อน เดี๋ยวค่อยมาแปลและเขียนใหม่นะครับ

This article contains a brief introduction to set up an FTP-Server under Debian Linux. Activation of an FTP server should be done similarly with other distributions of Linux. Debian 5.0 (x86) was used as the test system.

Contents

1. Installation of the required proftpd Package
2. Adjusting the Configuration
3. Anonymous FTP
4. Re-loading the Configuration and Re-starting the FTP Server
5. Links

Installation of the required proftpd Package

ProFTPd FTP-Server was used for this introduction because of its simply installation and configuration.

apt-get install proftpd

If the package cannot be found, update the local list of packages using:

apt-get update

If the package still cannot be installed after that, check the /etc/apt/sources.list on the appropriate Debian mirror server. You will find more information about this in the article Debian Mirror.

Indicate in the subsequent inquiry whether the FTP server should act as a standalone server (standalone) or as a service of inetd. In this example, the standalone option has been selected. Adjusting the Configuration

Our configuration assumes that we will login using system users found in the ftpuser group.

In order to adjust the configuration to your needs, edit the /etc/proftpd/proftpd.conf file.

If you are not using IPv6, this feature should be deactivated first:

UseIPv6 off

After that, we will add the following instruction at the end of the file:

<Global>
    RequireValidShell off
</Global>

DefaultRoot ~ ftpuser

<Limit LOGIN>
    DenyGroup !ftpuser
</Limit>

What do the instructions mean?

As a first step, we told ProFTPd that users wanting to login do not need a shell. Afterwards, we instructed ProFTPd to lock users in their home directory using DefaultRoot. Finally, we specified that only those users who are members of the ftpuser group could login.

We will now restart our FTP server so that our configuration takes effect:

/etc/init.d/proftpd restart

Then, we will create the ftpuser group and a first user that will be able to login.

addgroup ftpuser

Now, we create the user:

adduser ftpbenutzer -shell /bin/false -home /var/www

Finally, we assign the user to the ftpuser group:

adduser ftpbenutzer ftpuser

That’s everything. You should now be able to login with the user via FTP.

You have to run sudo deluser username groupname to delete a user from it's corresponding group. And run this sudo deluser --group groupname command to delete a group.

Anonymous FTP

By adding the following section to the etc/proftpd/proftpd.conf file, you will also give anonymous users (read) access to the FTP area:

.
.
.
<Anonymous ~ftp>
  User                          ftp
  Group                         nogroup
  # We want clients to be able to login with "anonymous" as well as "ftp"
  UserAlias                     anonymous ftp
  # Cosmetic changes, all files belong to ftp user
  DirFakeUser   on ftp
  DirFakeGroup on ftp

  RequireValidShell             off

  # Limit the maximum number of anonymous logins
  MaxClients                    10

  # We want 'welcome.msg' displayed at login, and '.message' displayed
  # in each newly chdired directory.
  DisplayLogin                  welcome.msg
  DisplayFirstChdir             .message

  # Limit WRITE everywhere in the anonymous chroot
  <Directory *>
    <Limit WRITE>
      DenyAll
    </Limit>
  </Directory>

#   # Uncomment this if you're brave.
#   # <Directory incoming>
#   #   # Umask 022 is a good standard umask to prevent new files and dirs
#   #   # (second parm) from being group and world writable.
#   #   Umask                           022  022
#   #            <Limit READ WRITE>
#   #            DenyAll
#   #            </Limit>
#   #            <Limit STOR>
#   #            AllowAll
#   #            </Limit>
#   # </Directory>

</Anonymous>
.
.
.

To make sure, that user "ftp" is able to login anonymously to ftp-space, you have to add the user to the group "ftpuser":

adduser ftp ftpuser

Re-loading the Configuration and Re-starting the FTP Server

The configuration will have to be re-loaded after the adjustments to the /etc/proftpd/proftpd.conf file:

/etc/init.d/proftpd reload

Because the FTP server will be stopped when re-loading the configuration, it will also have to be re-started afterwards:

/etc/init.d/proftpd start


Links

• http://www.proftpd.org/ - Web site for the project
• http://www.castaglia.org/proftpd/ - Web site for the primary developer with numerous HOWTO pages and background information