ProFTPD module mod_vroot

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ProFTPD module mod_vroot

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This module is contained in the mod_vroot.c file for ProFTPD 1.3.x, and is not compiled by default. Installation instructions are discussed here. The purpose of this module to is to implement a virtual chroot capability that does not require root privileges. The mod_vroot module provides this capability by using ProFTPD's FS API, available as of 1.2.8rc1.
The most current version of mod_vroot can be found at:

  http://www.castaglia.org/proftpd/

Author

Please contact TJ Saunders <tj at castaglia.org> with any questions, concerns, or suggestions regarding this module.

Thanks

2003-08-26: Thanks to Oskar Liljeblad for the elegant patch that added symlink support.

Directives

• VRootAlias
• VRootEngine
• VRootLog
• VRootOptions
• VRootServerRoot

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VRootAlias

Syntax: VRootAlias src-path dst-path
Default: None
Context: server config, <VirtualHost>, <Global>
Module: mod_vroot
Compatibility: 1.3.2 and later The VRootAlias directive is used to create an "alias" of a directory outside of the chroot area into the chroot. The dst-path parameter is a relative path, relative to the chroot area (i.e. the directory in which the session starts). The src-path parameter, on the other hand, is an absolute path, and may be to a file or directory.
For example, you might map a shared upload directory into a user's home directory using:

  <IfModule mod_vroot.c>
    VRootEngine on

    DefaultRoot ~
    VRootAlias /var/ftp/upload ~/upload
  </IfModule>

This will automatically create an "upload" directory to appear in the chroot area (in this case, the user's home directory). Note that this directive will not work if the VRootServerRoot is used.

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VRootEngine

Syntax: VRootEngine on|off
Default: None
Context: server config, <VirtualHost>, <Global>
Module: mod_vroot
Compatibility: 1.2.8rc1 and later The VRootEngine directive enables the virtual chroot engine implemented by mod_vroot. If enabled, the virtual chroot will be used in place of the operating system's chroot(2). This directive affects any DefaultRoot directives and any <Anonymous> contexts within the server context in which the VRootEngine directive appears.

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VRootLog

Syntax: VRootLog file
Default: None
Context: server config, <VirtualHost>, <Global>
Module: mod_vroot
Compatibility: 1.3.0rc1 and later The VRootLog directive is used to specify a log file for mod_vroot's reporting on a per-server basis. The file parameter given must be the full path to the file to use for logging.

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VRootOptions

Syntax: VRootOptions opt1 ...
Default: None
Context: "server config" <VirtualHost>, <Global>
Module: mod_vroot
Compatibility: 1.2.9rc2 and later The VRootOptions directive is used to configure various optional behavior of mod_vroot.
Example:

  VRootOptions allowSymlinks

The currently implemented options are:

• allowSymlinks
  Normally, any symlinks that point outside of the vroot area simply do not work. When the allowSymlinks option is enabled, these symlinks will be allowed. Note that by enabling symlinks, the efficacy of the vroot "jail" is reduced.

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VRootServerRoot

Syntax: VRootServerRoot path
Default: None
Context: "server config" <VirtualHost>, <Global>
Module: mod_vroot
Compatibility: 1.3.2rc1 and later The VRootServerRoot directive is used to configure a directory to which the mod_vroot module will perform a real chroot. The idea is that each <VirtualHost> can have its own directory to which a real chroot(2) system call is made; the user-specific home directories will be virtual roots underneath this directory. Thus some measure of security, via the chroot(2) system call, is provided by the kernel, while still allowing symlinked shared folders among users of this <VirtualHost>.
For example:

  <VirtualHost a.b.c.d>
    VRootEngine on
    VRootServerRoot /etc/ftpd/a.b.c.d/
    VRootOptions allowSymlinks
    DefaultRoot ~
    ...

  </VirtualHost>

See also: VRootOptions

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Installation

After unpacking and patching the latest proftpd-1.3.x source code, copy the mod_vroot.c file into:

  proftpd-dir/contrib/

Then follow the normal steps for using third-party modules in proftpd:

  ./configure --with-modules=mod_vroot
  make
  make install

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Author: $Author: tj $
Last Updated: $Date: 2009/10/19 16:30:18 $

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© Copyright 2000-2009 TJ Saunders
All Rights Reserved

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