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-<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 13. File, Directory and Share Access Controls</title><link rel="stylesheet" href="samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.60.1"><link rel="home" href="index.html" title="SAMBA Project Documentation"><link rel="up" href="optional.html" title="Part III. Advanced Configuration"><link rel="previous" href="groupmapping.html" title="Chapter 12. Mapping MS Windows and Unix Groups"><link rel="next" href="locking.html" title="Chapter 14. File and Record Locking"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 13. File, Directory and Share Access Controls</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="groupmapping.html">Prev</a> </td><th width="60%" align="center">Part III. Advanced Configuration</th><td width="20%" align="right"> <a accesskey="n" href="locking.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="AccessControls"></a>Chapter 13. File, Directory and Share Access Controls</h2></div><div><div class="author"><h3 class="author"><span class="firstname">John</span> <span class="othername">H.</span> <span class="surname">Terpstra</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt class="email">&lt;<a href="mailto:jht@samba.org">jht@samba.org</a>&gt;</tt></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Jeremy</span> <span class="surname">Allison</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt class="email">&lt;<a href="mailto:jra@samba.org">jra@samba.org</a>&gt;</tt></p></div></div></div></div><div><p class="pubdate">May 10, 2003</p></div></div><div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><a href="AccessControls.html#id2920239">Features and Benefits</a></dt><dt><a href="AccessControls.html#id2920364">File System Access Controls</a></dt><dd><dl><dt><a href="AccessControls.html#id2920382">MS Windows NTFS Comparison with Unix File Systems</a></dt><dt><a href="AccessControls.html#id2917299">Managing Directories</a></dt><dt><a href="AccessControls.html#id2917394">File and Directory Access Control</a></dt></dl></dd><dt><a href="AccessControls.html#id2917800">Share Definition Access Controls</a></dt><dd><dl><dt><a href="AccessControls.html#id2917828">User and Group Based Controls</a></dt><dt><a href="AccessControls.html#id2918100">File and Directory Permissions Based Controls</a></dt><dt><a href="AccessControls.html#id2918346">Miscellaneous Controls</a></dt></dl></dd><dt><a href="AccessControls.html#id2922930">Access Controls on Shares</a></dt><dd><dl><dt><a href="AccessControls.html#id2923002">Share Permissions Management</a></dt></dl></dd><dt><a href="AccessControls.html#id2923301">MS Windows Access Control Lists and Unix Interoperability</a></dt><dd><dl><dt><a href="AccessControls.html#id2923309">Managing UNIX permissions Using NT Security Dialogs</a></dt><dt><a href="AccessControls.html#id2923347">Viewing File Security on a Samba Share</a></dt><dt><a href="AccessControls.html#id2923426">Viewing file ownership</a></dt><dt><a href="AccessControls.html#id2923548">Viewing File or Directory Permissions</a></dt><dt><a href="AccessControls.html#id2923776">Modifying file or directory permissions</a></dt><dt><a href="AccessControls.html#id2923928">Interaction with the standard Samba create mask
- parameters</a></dt><dt><a href="AccessControls.html#id2924258">Interaction with the standard Samba file attribute
- mapping</a></dt></dl></dd><dt><a href="AccessControls.html#id2924333">Common Errors</a></dt><dd><dl><dt><a href="AccessControls.html#id2924347">Users can not write to a public share</a></dt><dt><a href="AccessControls.html#id2924726">I have set force user and Samba still makes root the owner of all the files
- I touch!</a></dt></dl></dd></dl></div><p>
-Advanced MS Windows users are frequently perplexed when file, directory and share manipulation of
-resources shared via Samba do not behave in the manner they might expect. MS Windows network
-administrators are often confused regarding network access controls and what is the best way to
-provide users with the type of access they need while protecting resources from the consequences
-of untoward access capabilities.
-</p><p>
-Unix administrators frequently are not familiar with the MS Windows environment and in particular
-have difficulty in visualizing what the MS Windows user wishes to achieve in attempts to set file
-and directory access permissions.
-</p><p>
-The problem lies in the differences in how file and directory permissions and controls work
-between the two environments. This difference is one that Samba can not completely hide, even
-though it does try to make the chasm transparent.
-</p><p>
-POSIX Access Control List technology has been available (along with Extended Attributes)
-for Unix for many years, yet there is little evidence today of any significant use. This
-explains to some extent the slow adoption of ACLs into commercial Linux products. MS Windows
-administrators are astounded at this given that ACLs were a foundational capability of the now
-decade old MS Windows NT operating system.
-</p><p>
-The purpose of this chapter is to present each of the points of control that are possible with
-Samba-3 in the hope that this will help the network administrator to find the optimum method
-for delivering the best environment for MS Windows desktop users.
-</p><p>
-This is an opportune point to mention that it should be borne in mind that Samba was created to
-provide a means of interoperability and interchange of data between two operating environments
-that are quite different. It was never the intent to make Unix/Linux like MS Windows NT. Instead
-the purpose was an is to provide a sufficient level of exchange of data between the two environments.
-What is available today extends well beyond early plans and expectations, yet the gap continues to
-shrink.
-</p><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2920239"></a>Features and Benefits</h2></div></div><div></div></div><p>
- Samba offers a lot of flexibility in file system access management. These are the key access control
- facilities present in Samba today:
- </p><div class="itemizedlist"><p class="title"><b>Samba Access Control Facilities</b></p><ul type="disc"><li><p>
- <span class="emphasis"><em>Unix File and Directory Permissions</em></span>
- </p><p>
- Samba honours and implements Unix file system access controls. Users
- who access a Samba server will do so as a particular MS Windows user.
- This information is passed to the Samba server as part of the logon or
- connection setup process. Samba uses this user identity to validate
- whether or not the user should be given access to file system resources
- (files and directories). This chapter provides an overview for those
- to whom the Unix permissions and controls are a little strange or unknown.
- </p></li><li><p>
- <span class="emphasis"><em>Samba Share Definitions</em></span>
- </p><p>
- In configuring share settings and controls in the <tt class="filename">smb.conf</tt> file
- the network administrator can exercise over-rides to native file
- system permissions and behaviours. This can be handy and convenient
- to affect behaviour that is more like what MS Windows NT users expect
- but it is seldom the <span class="emphasis"><em>best</em></span> way to achieve this.
- The basic options and techniques are described herein.
- </p></li><li><p>
- <span class="emphasis"><em>Samba Share ACLs</em></span>
- </p><p>
- Just like it is possible in MS Windows NT to set ACLs on shares
- themselves, so it is possible to do this in Samba.
- Very few people make use of this facility, yet it remains on of the
- easiest ways to affect access controls (restrictions) and can often
- do so with minimum invasiveness compared with other methods.
- </p></li><li><p>
- <span class="emphasis"><em>MS Windows ACLs through Unix POSIX ACLs</em></span>
- </p><p>
- The use of POSIX ACLs on Unix/Linux is possible ONLY if the underlying
- operating system supports them. If not, then this option will not be
- available to you. Current Unix technology platforms have native support
- for POSIX ACLs. There are patches for the Linux kernel that provide
- this also. Sadly, few Linux platforms ship today with native ACLs and
- Extended Attributes enabled. This chapter has pertinent information
- for users of platforms that support them.
- </p></li></ul></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2920364"></a>File System Access Controls</h2></div></div><div></div></div><p>
-Perhaps the most important recognition to be made is the simple fact that MS Windows NT4 / 200x / XP
-implement a totally divergent file system technology from what is provided in the Unix operating system
-environment. Firstly we should consider what the most significant differences are, then we shall look
-at how Samba helps to bridge the differences.
-</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2920382"></a>MS Windows NTFS Comparison with Unix File Systems</h3></div></div><div></div></div><p>
- Samba operates on top of the Unix file system. This means it is subject to Unix file system conventions
- and permissions. It also means that if the MS Windows networking environment requires file system
- behaviour that differs from unix file system behaviour then somehow Samba is responsible for emulating
- that in a transparent and consistent manner.
- </p><p>
- It is good news that Samba does this to a very large extent and on top of that provides a high degree
- of optional configuration to over-ride the default behaviour. We will look at some of these over-rides,
- but for the greater part we will stay within the bounds of default behaviour. Those wishing to explore
- to depths of control ability should review the <tt class="filename">smb.conf</tt> man page.
- </p><div class="variablelist"><p class="title"><b>File System Feature Comparison</b></p><dl><dt><span class="term">Name Space</span></dt><dd><p>
- MS Windows NT4 / 200x/ XP files names may be up to 254 characters long, Unix file names
- may be 1023 characters long. In MS Windows file extensions indicate particular file types,
- in Unix this is not so rigorously observed as all names are considered arbitrary.
- </p><p>
- What MS Windows calls a Folder, Unix calls a directory,
- </p></dd><dt><span class="term">Case Sensitivity</span></dt><dd><p>
- MS Windows file names are generally Upper Case if made up of 8.3 (ie: 8 character file name
- and 3 character extension. If longer than 8.3 file names are Case Preserving, and Case
- Insensitive.
- </p><p>
- Unix file and directory names are Case Sensitive and Case Preserving. Samba implements the
- MS Windows file name behaviour, but it does so as a user application. The Unix file system
- provides no mechanism to perform case insensitive file name lookups. MS Windows does this
- by default. This means that Samba has to carry the processing overhead to provide features
- that are NOT native to the Unix operating system environment.
- </p><p>
- Consider the following, all are unique Unix names but one single MS Windows file name:
- <tt class="computeroutput">
- MYFILE.TXT
- MyFile.txt
- myfile.txt
- </tt>
- So clearly, In an MS Windows file name space these three files CAN NOT co-exist! But in Unix
- they can. So what should Samba do if all three are present? Answer, the one that is lexically
- first will be accessible to MS Windows users, the others are invisible and unaccessible - any
- other solution would be suicidal.
- </p></dd><dt><span class="term">Directory Separators</span></dt><dd><p>
- MS Windows and DOS uses the back-slash '\' as a directory delimiter, Unix uses the forward-slash '/'
- as it's directory delimiter. This is transparently handled by Samba.
- </p></dd><dt><span class="term">Drive Identification</span></dt><dd><p>
- MS Windows products support a notion of drive letters, like <b class="command">C:</b> to represent
- disk partitions. Unix has NO concept if separate identifiers for file partitions since each
- such file system is <tt class="filename">mounted</tt> to become part of the over-all directory tree.
- The Unix directory tree begins at '/', just like the root of a DOS drive is specified like
- <b class="command">C:\</b>.
- </p></dd><dt><span class="term">File Naming Conventions</span></dt><dd><p>
- MS Windows generally never experiences file names that begin with a '.', while in Unix these
- are commonly found in a user's home directory. Files that begin with a '.' are typically
- either start up files for various Unix applications, or they may be files that contain
- start-up configuration data.
- </p></dd><dt><span class="term">Links and Short-Cuts</span></dt><dd><p>
- MS Windows make use of &quot;links and Short-Cuts&quot; that are actually special types of files that will
- redirect an attempt to execute the file to the real location of the file. Unix knows of file and directory
- links, but they are entirely different from what MS Windows users are used to.
- </p><p>
- Symbolic links are files in Unix that contain the actual location of the data (file OR directory). An
- operation (like read or write) will operate directly on the file referenced. Symbolic links are also
- referred to as 'soft links'. A hard link is something that MS Windows is NOT familiar with. It allows
- one physical file to be known simultaneously by more than one file name.
- </p></dd></dl></div><p>
- There are many other subtle differences that may cause the MS Windows administrator some temporary discomfort
- in the process of becoming familiar with Unix/Linux. These are best left for a text that is dedicated to the
- purpose of Unix/Linux training/education.
- </p></div><div xmlns:ns30="" class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2917299"></a>Managing Directories</h3></div></div><div></div></div><ns30:p>
- There are three basic operations for managing directories, <b class="command">create, delete, rename</b>.
- </ns30:p><div class="table"><a name="id2917317"></a><p class="title"><b>Table 13.1. Managing directories with unix and windows</b></p><table summary="Managing directories with unix and windows" border="1"><colgroup><col><col><col></colgroup><thead><tr><th align="center">Action</th><th align="center">MS Windows Command</th><th align="center">Unix Command</th></tr></thead><tbody><tr><td align="center">create</td><td align="center">md folder</td><td align="center">mkdir folder</td></tr><tr><td align="center">delete</td><td align="center">rd folder</td><td align="center">rmdir folder</td></tr><tr><td align="center">rename</td><td align="center">rename oldname newname</td><td align="center">mv oldname newname</td></tr></tbody></table></div><ns30:p>
- </ns30:p></div><div xmlns:ns31="" class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2917394"></a>File and Directory Access Control</h3></div></div><div></div></div><p>
- The network administrator is strongly advised to read foundational training manuals and reference materials
- regarding file and directory permissions maintenance. Much can be achieved with the basic Unix permissions
- without having to resort to more complex facilities like POSIX Access Control Lists (ACLs) or Extended
- Attributes (EAs).
- </p><ns31:p>
- Unix/Linux file and directory access permissions involves setting three (3) primary sets of data and one (1) control set.
- A Unix file listing looks as follows:-
-
- </ns31:p><pre class="screen">
- <tt class="prompt">jht@frodo:~/stuff&gt; </tt><b class="userinput"><tt>ls -la</tt></b>
- total 632
- drwxr-xr-x 13 jht users 816 2003-05-12 22:56 .
- drwxr-xr-x 37 jht users 3800 2003-05-12 22:29 ..
- d--------- 2 jht users 48 2003-05-12 22:29 muchado00
- d--x--x--x 2 jht users 48 2003-05-12 22:29 muchado01
- dr-xr-xr-x 2 jht users 48 2003-05-12 22:29 muchado02
- drwxrwxrwx 2 jht users 48 2003-05-12 22:29 muchado03
- drw-rw-rw- 2 jht users 48 2003-05-12 22:29 muchado04
- d-w--w--w- 2 jht users 48 2003-05-12 22:29 muchado05
- dr--r--r-- 2 jht users 48 2003-05-12 22:29 muchado06
- drwxrwxrwt 2 jht users 48 2003-05-12 22:29 muchado07
- drwsrwsrwx 2 jht users 48 2003-05-12 22:29 muchado08
- ---------- 1 jht users 1242 2003-05-12 22:31 mydata00.lst
- ---x--x--x 1 jht users 1674 2003-05-12 22:33 mydata01.lst
- --w--w--w- 1 jht users 7754 2003-05-12 22:33 mydata02.lst
- --wx-wx-wx 1 jht users 260179 2003-05-12 22:33 mydata03.lst
- -r--r--r-- 1 jht users 21017 2003-05-12 22:32 mydata04.lst
- -r-xr-xr-x 1 jht users 206339 2003-05-12 22:32 mydata05.lst
- -rw-rw-rw- 1 jht users 41105 2003-05-12 22:32 mydata06.lst
- -rwxrwxrwx 1 jht users 19312 2003-05-12 22:32 mydata07.lst
- <tt class="prompt">jht@frodo:~/stuff&gt;</tt>
- </pre><ns31:p>
- </ns31:p><p>
- The columns above represent (from left to right): permissions, no blocks used, owner, group, size (bytes), access date, access time, file name.
- </p><ns31:p>
- The permissions field is made up of:
-
- </ns31:p><pre class="programlisting">
- <i><span class="comment"> JRV: Put this into a diagram of some sort</span></i>
- [ type ] [ users ] [ group ] [ others ] [File, Directory Permissions]
- [ d | l ] [ r w x ] [ r w x ] [ r w x ]
- | | | | | | | | | | |
- | | | | | | | | | | |-----&gt; Can Execute, List files
- | | | | | | | | | |-------&gt; Can Write, Create files
- | | | | | | | | |---------&gt; Can Read, Read files
- | | | | | | | |---------------&gt; Can Execute, List files
- | | | | | | |-----------------&gt; Can Write, Create files
- | | | | | |-------------------&gt; Can Read, Read files
- | | | | |-------------------------&gt; Can Execute, List files
- | | | |---------------------------&gt; Can Write, Create files
- | | |-----------------------------&gt; Can Read, Read files
- | |-----------------------------------&gt; Is a symbolic Link
- |---------------------------------------&gt; Is a directory
- </pre><ns31:p>
- </ns31:p><ns31:p>
- Any bit flag may be unset. An unset bit flag is the equivalent of 'Can NOT' and is represented as a '-' character.
-
- </ns31:p><div class="example"><a name="id2917721"></a><p class="title"><b>Example 13.1. Example File</b></p><pre class="programlisting">
- -rwxr-x--- Means: The owner (user) can read, write, execute
- the group can read and execute
- everyone else can NOT do anything with it
- </pre></div><ns31:p>
-
- </ns31:p><p>
- Additional possibilities in the [type] field are: c = character device, b = block device, p = pipe device, s = Unix Domain Socket.
- </p><p>
- The letters `rwxXst' set permissions for the user, group and others as: read (r), write (w), execute (or access for directories) (x),
- execute only if the file is a directory or already has execute permission for some user (X), set user or group ID on execution (s),
- sticky (t).
- </p><p>
- When the sticky bit is set on a directory, files in that directory may be unlinked (deleted) or renamed only by root or their owner.
- Without the sticky bit, anyone able to write to the directory can delete or rename files. The sticky bit is commonly found on
- directories, such as /tmp, that are world-writable.
- </p><p>
- When the set user or group ID bit (s) is set on a directory, then all files created within it will be owned by the user and/or
- group whose 'set user or group' bit is set. This can be very helpful in setting up directories that for which it is desired that
- all users who are in a group should be able to write to and read from a file, particularly when it is undesirable for that file
- to be exclusively owned by a user who's primary group is not the group that all such users belong to.
- </p><p>
- When a directory is set <tt class="constant">drw-r-----</tt> this means that the owner can read and create (write) files in it, but because
- the (x) execute flags are not set files can not be listed (seen) in the directory by anyone. The group can read files in the
- directory but can NOT create new files. NOTE: If files in the directory are set to be readable and writable for the group, then
- group members will be able to write to (or delete) them.
- </p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2917800"></a>Share Definition Access Controls</h2></div></div><div></div></div><p>
-The following parameters in the <tt class="filename">smb.conf</tt> file sections that define a share control or affect access controls.
-Before using any of the following options please refer to the man page for <tt class="filename">smb.conf</tt>.
-</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2917828"></a>User and Group Based Controls</h3></div></div><div></div></div><p>
- User and group based controls can prove very useful. In some situations it is distinctly desirable to affect all
- file system operations as if a single user is doing this, the use of the <i class="parameter"><tt>force user</tt></i> and
- <i class="parameter"><tt>force group</tt></i> behaviour will achieve this. In other situations it may be necessary to affect a
- paranoia level of control to ensure that only particular authorised persons will be able to access a share or
- it's contents, here the use of the <i class="parameter"><tt>valid users</tt></i> or the <i class="parameter"><tt>invalid users</tt></i> may
- be most useful.
- </p><p>
- As always, it is highly advisable to use the least difficult to maintain and the least ambiguous method for
- controlling access. Remember, that when you leave the scene someone else will need to provide assistance and
- if that person finds too great a mess, or if they do not understand what you have done then there is risk of
- Samba being removed and an alternative solution being adopted.
- </p><div class="table"><a name="id2917887"></a><p class="title"><b>Table 13.2. User and Group Based Controls</b></p><table summary="User and Group Based Controls" border="1"><colgroup><col><col></colgroup><thead><tr><th align="center">Control Parameter</th><th align="center">Description - Action - Notes</th></tr></thead><tbody><tr><td>admin users</td><td><p>
- List of users who will be granted administrative privileges on the share.
- They will do all file operations as the super-user (root).
- Any user in this list will be able to do anything they like on the share,
- irrespective of file permissions.
- </p></td></tr><tr><td>force group</td><td><p>
- Specifies a UNIX group name that will be assigned as the default primary group
- for all users connecting to this service.
- </p></td></tr><tr><td>force user</td><td><p>
- Specifies a UNIX user name that will be assigned as the default user for all users connecting to this service.
- This is useful for sharing files. Incorrect use can cause security problems.
- </p></td></tr><tr><td>guest ok</td><td><p>
- If this parameter is set for a service, then no password is required to connect to the service. Privileges will be
- those of the guest account.
- </p></td></tr><tr><td>invalid users</td><td><p>
- List of users that should not be allowed to login to this service.
- </p></td></tr><tr><td>only user</td><td><p>
- Controls whether connections with usernames not in the user list will be allowed.
- </p></td></tr><tr><td>read list</td><td><p>
- List of users that are given read-only access to a service. Users in this list
- will not be given write access, no matter what the read only option is set to.
- </p></td></tr><tr><td>username</td><td><p>
- Refer to the <tt class="filename">smb.conf</tt> man page for more information - this is a complex and potentially misused parameter.
- </p></td></tr><tr><td>valid users</td><td><p>
- List of users that should be allowed to login to this service.
- </p></td></tr><tr><td>write list</td><td><p>
- List of users that are given read-write access to a service.
- </p></td></tr></tbody></table></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2918100"></a>File and Directory Permissions Based Controls</h3></div></div><div></div></div><p>
- The following file and directory permission based controls, if misused, can result in considerable difficulty to
- diagnose the cause of mis-configuration. Use them sparingly and carefully. By gradually introducing each one by one
- undesirable side-effects may be detected. In the event of a problem, always comment all of them out and then gradually
- re-introduce them in a controlled fashion.
- </p><div class="table"><a name="id2918120"></a><p class="title"><b>Table 13.3. File and Directory Permission Based Controls</b></p><table summary="File and Directory Permission Based Controls" border="1"><colgroup><col><col></colgroup><thead><tr><th align="center">Control Parameter</th><th align="center">Description - Action - Notes</th></tr></thead><tbody><tr><td>create mask</td><td><p>
- Refer to the <tt class="filename">smb.conf</tt> man page.
- </p></td></tr><tr><td>directory mask</td><td><p>
- The octal modes used when converting DOS modes to UNIX modes when creating UNIX directories.
- See also: directory security mask.
- </p></td></tr><tr><td>dos filemode</td><td><p>
- Enabling this parameter allows a user who has write access to the file to modify the permissions on it.
- </p></td></tr><tr><td>force create mode</td><td><p>
- This parameter specifies a set of UNIX mode bit permissions that will always be set on a file created by Samba.
- </p></td></tr><tr><td>force directory mode</td><td><p>
- This parameter specifies a set of UNIX mode bit permissions that will always be set on a directory created by Samba.
- </p></td></tr><tr><td>force directory security mode</td><td><p>
- Controls UNIX permission bits modified when a Windows NT client is manipulating UNIX permissions on a directory
- </p></td></tr><tr><td>force security mode</td><td><p>
- Controls UNIX permission bits modified when a Windows NT client manipulates UNIX permissions.
- </p></td></tr><tr><td>hide unreadable</td><td><p>
- Prevents clients from seeing the existence of files that cannot be read.
- </p></td></tr><tr><td>hide unwriteable files</td><td><p>
- Prevents clients from seeing the existence of files that cannot be written to. Unwriteable directories are shown as usual.
- </p></td></tr><tr><td>nt acl support</td><td><p>
- This parameter controls whether smbd will attempt to map UNIX permissions into Windows NT access control lists.
- </p></td></tr><tr><td>security mask</td><td><p>
- Controls UNIX permission bits modified when a Windows NT client is manipulating the UNIX permissions on a file.
- </p></td></tr></tbody></table></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2918346"></a>Miscellaneous Controls</h3></div></div><div></div></div><p>
- The following are documented because of the prevalence of administrators creating inadvertant barriers to file
- access by not understanding the full implications of <tt class="filename">smb.conf</tt> file settings.
- </p><div class="table"><a name="id2918367"></a><p class="title"><b>Table 13.4. Other Controls</b></p><table summary="Other Controls" border="1"><colgroup><col><col></colgroup><thead><tr><th align="center">Control Parameter</th><th align="center">Description - Action - Notes</th></tr></thead><tbody><tr><td>case sensitive, default case, short preserve case</td><td><p>
- This means that all file name lookup will be done in a case sensitive manner.
- Files will be created with the precise filename Samba received from the MS Windows client.
- </p></td></tr><tr><td>csc policy</td><td><p>
- Client Side Caching Policy - parallels MS Windows client side file caching capabilities.
- </p></td></tr><tr><td>dont descend</td><td><p>
- Allows to specify a comma-delimited list of directories that the server should always show as empty.
- </p></td></tr><tr><td>dos filetime resolution</td><td><p>
- This option is mainly used as a compatibility option for Visual C++ when used against Samba shares.
- </p></td></tr><tr><td>dos filetimes</td><td><p>
- DOS and Windows allows users to change file time stamps if they can write to the file. POSIX semantics prevent this.
- This options allows DOS and Windows behaviour.
- </p></td></tr><tr><td>fake oplocks</td><td><p>
- Oplocks are the way that SMB clients get permission from a server to locally cache file operations. If a server grants an
- oplock then the client is free to assume that it is the only one accessing the file and it will aggressively cache file data.
- </p></td></tr><tr><td>hide dot files, hide files, veto files</td><td><p>
- Note: MS Windows Explorer allows over-ride of files marked as hidden so they will still be visible.
- </p></td></tr><tr><td>read only</td><td><p>
- If this parameter is yes, then users of a service may not create or modify files in the service's directory.
- </p></td></tr><tr><td>veto files</td><td><p>
- List of files and directories that are neither visible nor accessible.
- </p></td></tr></tbody></table></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2922930"></a>Access Controls on Shares</h2></div></div><div></div></div><p>
- This section deals with how to configure Samba per share access control restrictions.
- By default, Samba sets no restrictions on the share itself. Restrictions on the share itself
- can be set on MS Windows NT4/200x/XP shares. This can be a very effective way to limit who can
- connect to a share. In the absence of specific restrictions the default setting is to allow
- the global user <tt class="constant">Everyone</tt> Full Control (ie: Full control, Change and Read).
- </p><p>
- At this time Samba does NOT provide a tool for configuring access control setting on the Share
- itself. Samba does have the capacity to store and act on access control settings, but the only
- way to create those settings is to use either the NT4 Server Manager or the Windows 200x MMC for
- Computer Management.
- </p><p>
- Samba stores the per share access control settings in a file called <tt class="filename">share_info.tdb</tt>.
- The location of this file on your system will depend on how samba was compiled. The default location
- for Samba's tdb files is under <tt class="filename">/usr/local/samba/var</tt>. If the <tt class="filename">tdbdump</tt>
- utility has been compiled and installed on your system, then you can examine the contents of this file
- by: <b class="userinput"><tt>tdbdump share_info.tdb</tt></b>.
- </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2923002"></a>Share Permissions Management</h3></div></div><div></div></div><p>
- The best tool for the task is platform dependant. Choose the best tool for your environment.
- </p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2923015"></a>Windows NT4 Workstation/Server</h4></div></div><div></div></div><p>
- The tool you need to use to manage share permissions on a Samba server is the NT Server Manager.
- Server Manager is shipped with Windows NT4 Server products but not with Windows NT4 Workstation.
- You can obtain the NT Server Manager for MS Windows NT4 Workstation from Microsoft - see details below.
- </p><div class="procedure"><p class="title"><b>Procedure 13.1. Instructions</b></p><ol type="1"><li><p>
- Launch the <span class="application">NT4 Server Manager</span>, click on the Samba server you want to administer, then from the menu
- select <span class="guimenu">Computer</span>, then click on the <span class="guimenuitem">Shared Directories</span> entry.
- </p></li><li><p>
- Now click on the share that you wish to manage, then click on the <span class="guilabel">Properties</span> tab, next click on
- the <span class="guilabel">Permissions</span> tab. Now you can add or change access control settings as you wish.
- </p></li></ol></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2923098"></a>Windows 200x/XP</h4></div></div><div></div></div><p>
- On <span class="application">MS Windows NT4/200x/XP</span> system access control lists on the share itself are set using native
- tools, usually from filemanager. For example, in Windows 200x: right click on the shared folder,
- then select <span class="guimenuitem">Sharing</span>, then click on <span class="guilabel">Permissions</span>. The default
- Windows NT4/200x permission allows <span class="emphasis"><em>Everyone</em></span> Full Control on the Share.
- </p><p>
- MS Windows 200x and later all comes with a tool called the <span class="application">Computer Management</span> snap-in for the
- Microsoft Management Console (MMC). This tool is located by clicking on <tt class="filename">Control Panel -&gt;
- Administrative Tools -&gt; Computer Management</tt>.
- </p><div class="procedure"><p class="title"><b>Procedure 13.2. Instructions</b></p><ol type="1"><li><p>
- After launching the MMC with the Computer Management snap-in, click on the menu item <span class="guimenuitem">Action</span>,
- select <span class="guilabel">Connect to another computer</span>. If you are not logged onto a domain you will be prompted
- to enter a domain login user identifier and a password. This will authenticate you to the domain.
- If you where already logged in with administrative privilege this step is not offered.
- </p></li><li><p>
- If the Samba server is not shown in the <span class="guilabel">Select Computer</span> box, then type in the name of the target
- Samba server in the field <span class="guilabel">Name:</span>. Now click on the <span class="guibutton">[+]</span> next to
- <span class="guilabel">System Tools</span>, then on the <span class="guibutton">[+]</span> next to <span class="guilabel">Shared Folders</span> in the
- left panel.
- </p></li><li><p>
- Now in the right panel, double-click on the share you wish to set access control permissions on.
- Then click on the tab <span class="guilabel">Share Permissions</span>. It is now possible to add access control entities
- to the shared folder. Do NOT forget to set what type of access (full control, change, read) you
- wish to assign for each entry.
- </p></li></ol></div><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>
- Be careful. If you take away all permissions from the <tt class="constant">Everyone</tt> user without removing this user
- then effectively no user will be able to access the share. This is a result of what is known as
- ACL precedence. ie: Everyone with <span class="emphasis"><em>no access</em></span> means that MaryK who is part of the group
- <tt class="constant">Everyone</tt> will have no access even if this user is given explicit full control access.
- </p></div></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2923301"></a>MS Windows Access Control Lists and Unix Interoperability</h2></div></div><div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2923309"></a>Managing UNIX permissions Using NT Security Dialogs</h3></div></div><div></div></div><p>Windows NT clients can use their native security settings
- dialog box to view and modify the underlying UNIX permissions.</p><p>Note that this ability is careful not to compromise
- the security of the UNIX host Samba is running on, and
- still obeys all the file permission rules that a Samba
- administrator can set.</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
- All access to Unix/Linux system file via Samba is controlled at
- the operating system file access control level. When trying to
- figure out file access problems it is vitally important to identify
- the identity of the Windows user as it is presented by Samba at
- the point of file access. This can best be determined from the
- Samba log files.
- </p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2923347"></a>Viewing File Security on a Samba Share</h3></div></div><div></div></div><p>From an NT4/2000/XP client, single-click with the right
- mouse button on any file or directory in a Samba mounted
- drive letter or UNC path. When the menu pops-up, click
- on the <span class="guilabel">Properties</span> entry at the bottom of
- the menu. This brings up the file properties dialog
- box. Click on the tab <span class="guilabel">Security</span> and you
- will see three buttons, <span class="guibutton">Permissions</span>,
- <span class="guibutton">Auditing</span>, and <span class="guibutton">Ownership</span>.
- The <span class="guibutton">Auditing</span> button will cause either
- an error message <span class="errorname">A requested privilege is not held
- by the client</span> to appear if the user is not the
- NT Administrator, or a dialog which is intended to allow an
- Administrator to add auditing requirements to a file if the
- user is logged on as the NT Administrator. This dialog is
- non-functional with a Samba share at this time, as the only
- useful button, the <span class="guibutton">Add</span> button will not currently
- allow a list of users to be seen.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2923426"></a>Viewing file ownership</h3></div></div><div></div></div><p>Clicking on the <span class="guibutton">Ownership</span> button
- brings up a dialog box telling you who owns the given file. The
- owner name will be of the form :</p><p><b class="command">&quot;SERVER\user (Long name)&quot;</b></p><p>Where <i class="replaceable"><tt>SERVER</tt></i> is the NetBIOS name of
- the Samba server, <i class="replaceable"><tt>user</tt></i> is the user name of
- the UNIX user who owns the file, and <i class="replaceable"><tt>(Long name)</tt></i>
- is the descriptive string identifying the user (normally found in the
- GECOS field of the UNIX password database). Click on the
- <span class="guibutton">Close </span> button to remove this dialog.</p><p>If the parameter <i class="parameter"><tt>nt acl support</tt></i>
- is set to <tt class="constant">false</tt> then the file owner will
- be shown as the NT user <tt class="constant">&quot;Everyone&quot;</tt>.</p><p>The <span class="guibutton">Take Ownership</span> button will not allow
- you to change the ownership of this file to yourself (clicking on
- it will display a dialog box complaining that the user you are
- currently logged onto the NT client cannot be found). The reason
- for this is that changing the ownership of a file is a privileged
- operation in UNIX, available only to the <span class="emphasis"><em>root</em></span>
- user. As clicking on this button causes NT to attempt to change
- the ownership of a file to the current user logged into the NT
- client this will not work with Samba at this time.</p><p>There is an NT chown command that will work with Samba
- and allow a user with Administrator privilege connected
- to a Samba server as root to change the ownership of
- files on both a local NTFS filesystem or remote mounted NTFS
- or Samba drive. This is available as part of the <span class="application">Seclib
- </span> NT security library written by Jeremy Allison of
- the Samba Team, available from the main Samba ftp site.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2923548"></a>Viewing File or Directory Permissions</h3></div></div><div></div></div><p>The third button is the <span class="guibutton">Permissions</span>
- button. Clicking on this brings up a dialog box that shows both
- the permissions and the UNIX owner of the file or directory.
- The owner is displayed in the form :</p><p><b class="command">&quot;<i class="replaceable"><tt>SERVER</tt></i>\
- <i class="replaceable"><tt>user</tt></i>
- <i class="replaceable"><tt>(Long name)</tt></i>&quot;</b></p><p>Where <i class="replaceable"><tt>SERVER</tt></i> is the NetBIOS name of
- the Samba server, <i class="replaceable"><tt>user</tt></i> is the user name of
- the UNIX user who owns the file, and <i class="replaceable"><tt>(Long name)</tt></i>
- is the descriptive string identifying the user (normally found in the
- GECOS field of the UNIX password database).</p><p>If the parameter <i class="parameter"><tt>nt acl support</tt></i>
- is set to <tt class="constant">false</tt> then the file owner will
- be shown as the NT user <tt class="constant">&quot;Everyone&quot;</tt> and the
- permissions will be shown as NT &quot;Full Control&quot;.</p><p>The permissions field is displayed differently for files
- and directories, so I'll describe the way file permissions
- are displayed first.</p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2923639"></a>File Permissions</h4></div></div><div></div></div><p>The standard UNIX user/group/world triplet and
- the corresponding &quot;read&quot;, &quot;write&quot;, &quot;execute&quot; permissions
- triplets are mapped by Samba into a three element NT ACL
- with the 'r', 'w', and 'x' bits mapped into the corresponding
- NT permissions. The UNIX world permissions are mapped into
- the global NT group <tt class="constant">Everyone</tt>, followed
- by the list of permissions allowed for UNIX world. The UNIX
- owner and group permissions are displayed as an NT
- <span class="guiicon">user</span> icon and an NT <span class="guiicon">local
- group</span> icon respectively followed by the list
- of permissions allowed for the UNIX user and group.</p><p>As many UNIX permission sets don't map into common
- NT names such as <tt class="constant">read</tt>, <tt class="constant">
- &quot;change&quot;</tt> or <tt class="constant">full control</tt> then
- usually the permissions will be prefixed by the words <tt class="constant">
- &quot;Special Access&quot;</tt> in the NT display list.</p><p>But what happens if the file has no permissions allowed
- for a particular UNIX user group or world component ? In order
- to allow &quot;no permissions&quot; to be seen and modified then Samba
- overloads the NT <b class="command">&quot;Take Ownership&quot;</b> ACL attribute
- (which has no meaning in UNIX) and reports a component with
- no permissions as having the NT <b class="command">&quot;O&quot;</b> bit set.
- This was chosen of course to make it look like a zero, meaning
- zero permissions. More details on the decision behind this will
- be given below.</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2923731"></a>Directory Permissions</h4></div></div><div></div></div><p>Directories on an NT NTFS file system have two
- different sets of permissions. The first set of permissions
- is the ACL set on the directory itself, this is usually displayed
- in the first set of parentheses in the normal <tt class="constant">&quot;RW&quot;</tt>
- NT style. This first set of permissions is created by Samba in
- exactly the same way as normal file permissions are, described
- above, and is displayed in the same way.</p><p>The second set of directory permissions has no real meaning
- in the UNIX permissions world and represents the <tt class="constant">
- inherited</tt> permissions that any file created within
- this directory would inherit.</p><p>Samba synthesises these inherited permissions for NT by
- returning as an NT ACL the UNIX permission mode that a new file
- created by Samba on this share would receive.</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2923776"></a>Modifying file or directory permissions</h3></div></div><div></div></div><p>Modifying file and directory permissions is as simple
- as changing the displayed permissions in the dialog box, and
- clicking the <span class="guibutton">OK</span> button. However, there are
- limitations that a user needs to be aware of, and also interactions
- with the standard Samba permission masks and mapping of DOS
- attributes that need to also be taken into account.</p><p>If the parameter <i class="parameter"><tt>nt acl support</tt></i>
- is set to <tt class="constant">false</tt> then any attempt to set
- security permissions will fail with an <span class="errorname">&quot;Access Denied&quot;
- </span> message.</p><p>The first thing to note is that the <span class="guibutton">&quot;Add&quot;</span>
- button will not return a list of users in Samba (it will give
- an error message of <span class="errorname">The remote procedure call failed
- and did not execute</span>). This means that you can only
- manipulate the current user/group/world permissions listed in
- the dialog box. This actually works quite well as these are the
- only permissions that UNIX actually has.</p><p>If a permission triplet (either user, group, or world)
- is removed from the list of permissions in the NT dialog box,
- then when the <span class="guibutton">OK</span> button is pressed it will
- be applied as &quot;no permissions&quot; on the UNIX side. If you then
- view the permissions again the &quot;no permissions&quot; entry will appear
- as the NT <b class="command">&quot;O&quot;</b> flag, as described above. This
- allows you to add permissions back to a file or directory once
- you have removed them from a triplet component.</p><p>As UNIX supports only the &quot;r&quot;, &quot;w&quot; and &quot;x&quot; bits of
- an NT ACL then if other NT security attributes such as &quot;Delete
- access&quot; are selected then they will be ignored when applied on
- the Samba server.</p><p>When setting permissions on a directory the second
- set of permissions (in the second set of parentheses) is
- by default applied to all files within that directory. If this
- is not what you want you must uncheck the <span class="guilabel">Replace
- permissions on existing files</span> checkbox in the NT
- dialog before clicking <span class="guibutton">OK</span>.</p><p>If you wish to remove all permissions from a
- user/group/world component then you may either highlight the
- component and click the <span class="guibutton">Remove</span> button,
- or set the component to only have the special <tt class="constant">Take
- Ownership</tt> permission (displayed as <b class="command">&quot;O&quot;
- </b>) highlighted.</p></div><div xmlns:ns32="" class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2923928"></a>Interaction with the standard Samba create mask
- parameters</h3></div></div><div></div></div><ns32:p>There are four parameters
- to control interaction with the standard Samba create mask parameters.
- These are :
-
- </ns32:p><table class="simplelist" border="0" summary="Simple list"><tr><td><i class="parameter"><tt>security mask</tt></i></td></tr><tr><td><i class="parameter"><tt>force security mode</tt></i></td></tr><tr><td><i class="parameter"><tt>directory security mask</tt></i></td></tr><tr><td><i class="parameter"><tt>force directory security mode</tt></i></td></tr></table><ns32:p>
-
- </ns32:p><p>Once a user clicks <span class="guibutton">OK</span> to apply the
- permissions Samba maps the given permissions into a user/group/world
- r/w/x triplet set, and then will check the changed permissions for a
- file against the bits set in the <a href="smb.conf.5.html#SECURITYMASK" target="_top">
- <i class="parameter"><tt>security mask</tt></i></a> parameter. Any bits that
- were changed that are not set to '1' in this parameter are left alone
- in the file permissions.</p><p>Essentially, zero bits in the <i class="parameter"><tt>security mask</tt></i>
- mask may be treated as a set of bits the user is <span class="emphasis"><em>not</em></span>
- allowed to change, and one bits are those the user is allowed to change.
- </p><p>If not set explicitly this parameter is set to the same value as
- the <a href="smb.conf.5.html#CREATEMASK" target="_top"><i class="parameter"><tt>create mask
- </tt></i></a> parameter. To allow a user to modify all the
- user/group/world permissions on a file, set this parameter
- to 0777.</p><p>Next Samba checks the changed permissions for a file against
- the bits set in the <a href="smb.conf.5.html#FORCESECURITYMODE" target="_top">
- <i class="parameter"><tt>force security mode</tt></i></a> parameter. Any bits
- that were changed that correspond to bits set to '1' in this parameter
- are forced to be set.</p><p>Essentially, bits set in the <i class="parameter"><tt>force security mode
- </tt></i> parameter may be treated as a set of bits that, when
- modifying security on a file, the user has always set to be 'on'.</p><p>If not set explicitly this parameter is set to the same value
- as the <a href="smb.conf.5.html#FORCECREATEMODE" target="_top"><i class="parameter"><tt>force
- create mode</tt></i></a> parameter.
- To allow a user to modify all the user/group/world permissions on a file
- with no restrictions set this parameter to 000.</p><p>The <i class="parameter"><tt>security mask</tt></i> and <i class="parameter"><tt>force
- security mode</tt></i> parameters are applied to the change
- request in that order.</p><p>For a directory Samba will perform the same operations as
- described above for a file except using the parameter <i class="parameter"><tt>
- directory security mask</tt></i> instead of <i class="parameter"><tt>security
- mask</tt></i>, and <i class="parameter"><tt>force directory security mode
- </tt></i> parameter instead of <i class="parameter"><tt>force security mode
- </tt></i>.</p><p>The <i class="parameter"><tt>directory security mask</tt></i> parameter
- by default is set to the same value as the <i class="parameter"><tt>directory mask
- </tt></i> parameter and the <i class="parameter"><tt>force directory security
- mode</tt></i> parameter by default is set to the same value as
- the <i class="parameter"><tt>force directory mode</tt></i> parameter. </p><p>In this way Samba enforces the permission restrictions that
- an administrator can set on a Samba share, whilst still allowing users
- to modify the permission bits within that restriction.</p><p>If you want to set up a share that allows users full control
- in modifying the permission bits on their files and directories and
- doesn't force any particular bits to be set 'on', then set the following
- parameters in the <tt class="filename">smb.conf</tt> file in that share specific section :
- </p><table class="simplelist" border="0" summary="Simple list"><tr><td><i class="parameter"><tt>security mask = 0777</tt></i></td></tr><tr><td><i class="parameter"><tt>force security mode = 0</tt></i></td></tr><tr><td><i class="parameter"><tt>directory security mask = 0777</tt></i></td></tr><tr><td><i class="parameter"><tt>force directory security mode = 0</tt></i></td></tr></table></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2924258"></a>Interaction with the standard Samba file attribute
- mapping</h3></div></div><div></div></div><p>Samba maps some of the DOS attribute bits (such as &quot;read
- only&quot;) into the UNIX permissions of a file. This means there can
- be a conflict between the permission bits set via the security
- dialog and the permission bits set by the file attribute mapping.
- </p><p>One way this can show up is if a file has no UNIX read access
- for the owner it will show up as &quot;read only&quot; in the standard
- file attributes tabbed dialog. Unfortunately this dialog is
- the same one that contains the security info in another tab.</p><p>What this can mean is that if the owner changes the permissions
- to allow themselves read access using the security dialog, clicks
- <span class="guibutton">OK</span> to get back to the standard attributes tab
- dialog, and then clicks <span class="guibutton">OK</span> on that dialog, then
- NT will set the file permissions back to read-only (as that is what
- the attributes still say in the dialog). This means that after setting
- permissions and clicking <span class="guibutton">OK</span> to get back to the
- attributes dialog you should always hit <span class="guibutton">Cancel</span>
- rather than <span class="guibutton">OK</span> to ensure that your changes
- are not overridden.</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2924333"></a>Common Errors</h2></div></div><div></div></div><p>
-File, Directory and Share access problems are very common on the mailing list. The following
-are examples taken from the mailing list in recent times.
-</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2924347"></a>Users can not write to a public share</h3></div></div><div></div></div><p>
- &#8220;<span class="quote">
- We are facing some troubles with file / directory permissions. I can log on the domain as admin user(root),
- and there's a public share, on which everyone needs to have permission to create / modify files, but only
- root can change the file, no one else can. We need to constantly go to server to
- <b class="userinput"><tt>chgrp -R users *</tt></b> and <b class="userinput"><tt>chown -R nobody *</tt></b> to allow others users to change the file.
- </span>&#8221;
- </p><p>
- There are many ways to solve this problem, here are a few hints:
- </p><div class="procedure"><p class="title"><b>Procedure 13.3. Example Solution:</b></p><ol type="1"><li><p>
- Go to the top of the directory that is shared
- </p></li><li xmlns:ns33=""><ns33:p>
- Set the ownership to what ever public owner and group you want
- </ns33:p><pre class="programlisting">
- find 'directory_name' -type d -exec chown user.group {}\;
- find 'directory_name' -type d -exec chmod 6775 'directory_name'
- find 'directory_name' -type f -exec chmod 0775 {} \;
- find 'directory_name' -type f -exec chown user.group {}\;
- </pre><ns33:p>
- </ns33:p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
- The above will set the 'sticky bit' on all directories. Read your
- Unix/Linux man page on what that does. It causes the OS to assign
- to all files created in the directories the ownership of the
- directory.
- </p></div></li><li xmlns:ns34=""><ns34:p>
-
- Directory is: <i class="replaceable"><tt>/foodbar</tt></i>
- </ns34:p><pre class="screen">
- <tt class="prompt">$ </tt><b class="userinput"><tt>chown jack.engr /foodbar</tt></b>
- </pre><ns34:p>
- </ns34:p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><ns34:p>
- </ns34:p><p>This is the same as doing:</p><ns34:p>
- </ns34:p><pre class="screen">
- <tt class="prompt">$ </tt><b class="userinput"><tt>chown jack /foodbar</tt></b>
- <tt class="prompt">$ </tt><b class="userinput"><tt>chgrp engr /foodbar</tt></b>
- </pre><ns34:p>
- </ns34:p></div></li><li xmlns:ns35=""><ns35:p>Now do:
-
- </ns35:p><pre class="screen">
- <tt class="prompt">$ </tt><b class="userinput"><tt>chmod 6775 /foodbar</tt></b>
- <tt class="prompt">$ </tt><b class="userinput"><tt>ls -al /foodbar/..</tt></b>
- </pre><ns35:p>
-
- </ns35:p><ns35:p>You should see:
- </ns35:p><pre class="screen">
- drwsrwsr-x 2 jack engr 48 2003-02-04 09:55 foodbar
- </pre><ns35:p>
- </ns35:p></li><li xmlns:ns36=""><ns36:p>Now do:
- </ns36:p><pre class="screen">
- <tt class="prompt">$ </tt><b class="userinput"><tt>su - jill</tt></b>
- <tt class="prompt">$ </tt><b class="userinput"><tt>cd /foodbar</tt></b>
- <tt class="prompt">$ </tt><b class="userinput"><tt>touch Afile</tt></b>
- <tt class="prompt">$ </tt><b class="userinput"><tt>ls -al</tt></b>
- </pre><ns36:p>
- </ns36:p><ns36:p>
- You should see that the file <tt class="filename">Afile</tt> created by Jill will have ownership
- and permissions of Jack, as follows:
- </ns36:p><pre class="screen">
- -rw-r--r-- 1 jack engr 0 2003-02-04 09:57 Afile
- </pre><ns36:p>
- </ns36:p></li><li xmlns:ns37=""><ns37:p>
- Now in your <tt class="filename">smb.conf</tt> for the share add:
- </ns37:p><pre class="programlisting">
- force create mode = 0775
- force directory mode = 6775
- </pre><ns37:p>
- </ns37:p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
- The above are only needed <span class="emphasis"><em>if</em></span> your users are <span class="emphasis"><em>not</em></span> members of the group
- you have used. ie: Within the OS do not have write permission on the directory.
- </p></div><ns37:p>
- An alternative is to set in the <tt class="filename">smb.conf</tt> entry for the share:
- </ns37:p><pre class="programlisting">
- force user = jack
- force group = engr
- </pre><ns37:p>
- </ns37:p></li></ol></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2924726"></a>I have set force user and Samba still makes <span class="emphasis"><em>root</em></span> the owner of all the files
- I touch!</h3></div></div><div></div></div><p>
- When you have a user in 'admin users', Samba will always do file operations for
- this user as <span class="emphasis"><em>root</em></span>, even if <i class="parameter"><tt>force user</tt></i> has been set.
- </p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="groupmapping.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="optional.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="locking.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 12. Mapping MS Windows and Unix Groups </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 14. File and Record Locking</td></tr></table></div></body></html>