samba-mirror/docs-xml/manpages/vfs_zfsacl.8.xml

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
<refentry id="vfs_zfsacl.8">

<refmeta>
	<refentrytitle>vfs_zfsacl</refentrytitle>
	<manvolnum>8</manvolnum>
	<refmiscinfo class="source">Samba</refmiscinfo>
	<refmiscinfo class="manual">System Administration tools</refmiscinfo>
	<refmiscinfo class="version">&doc.version;</refmiscinfo>
</refmeta>


<refnamediv>
	<refname>vfs_zfsacl</refname>
	<refpurpose>ZFS ACL samba module</refpurpose>
</refnamediv>

<refsynopsisdiv>
	<cmdsynopsis>
		<command>vfs objects = zfsacl</command>
	</cmdsynopsis>
</refsynopsisdiv>

<refsect1>
	<title>DESCRIPTION</title>

	<para>This VFS module is part of the
	<citerefentry><refentrytitle>samba</refentrytitle>
	<manvolnum>7</manvolnum></citerefentry> suite.</para>

	<para>The <command>zfsacl</command> VFS module is the home
	for all ACL extensions that Samba requires for proper integration
	with ZFS.
	</para>

	<para>Currently the zfsacl vfs module provides extensions in following areas :
	<itemizedlist>
	<listitem><para>NFSv4 ACL Interfaces with configurable options for ZFS</para></listitem>
	</itemizedlist>
	</para>

	<para><command>NOTE:</command>This module follows the posix-acl behaviour
	and hence allows permission stealing via chown. Samba might allow at a later
	point in time, to restrict the chown via this module as such restrictions
	are the responsibility of the underlying filesystem than of Samba.
	</para>

	<para>This module makes use of the smb.conf parameter
	<smbconfoption name="acl map full control">acl map full control</smbconfoption>
	When set to yes (the default), this parameter will add in the FILE_DELETE_CHILD
	bit on a returned ACE entry for a file (not a directory) that already
	contains all file permissions except for FILE_DELETE and FILE_DELETE_CHILD.
	This can prevent Windows applications that request GENERIC_ALL access
	from getting ACCESS_DENIED errors when running against a filesystem
	with NFSv4 compatible ACLs.
	</para>

	<para>ZFS has mutiple dataset configuration parameters that determine ACL behavior.
	Although the nuances of these parameters are outside the scope of this manpage, the
	"aclmode" and "aclinherit" are of particular importance for samba shares.
	For datasets that are intended solely as Samba shares, "aclmode = restricted"
	and "aclinherit = passthrough" provide inheritance behavior most consistent with NTFS ACLs.
	A "restricted" aclmode prevents chmod() on files that have a non-trivial ACL (one that
	cannot be expressed as a POSIX mode without loss of information). Consult the relevant ZFS
	manpages for further information.
	</para>

	<para>This module is stackable.</para>

	<para>Since Samba 4.0 all options are per share options.</para>

</refsect1>


<refsect1>
	<title>OPTIONS</title>

	<variablelist>

		<varlistentry>

		<term>nfs4:mode = [ simple | special ]</term>
		<listitem>
		<para>
		Controls substitution of special IDs (OWNER@ and GROUP@) on ZFS.
                The use of mode simple is recommended.
                In this mode only non inheriting ACL entries for the file owner
                and group are mapped to special IDs.
		</para>

		<para>The following MODEs are understood by the module:</para>
		<itemizedlist>
		<listitem><para><command>simple(default)</command> - use OWNER@ and GROUP@ special IDs for non inheriting ACEs only.</para></listitem>
		<listitem><para><command>special(deprecated)</command> - use OWNER@ and GROUP@ special IDs in ACEs for all file owner and group ACEs.</para></listitem>
		</itemizedlist>
		</listitem>

		</varlistentry>


		<varlistentry>
		<term>nfs4:acedup = [dontcare|reject|ignore|merge]</term>
		<listitem>
		<para>
		This parameter configures how Samba handles duplicate ACEs encountered in ZFS ACLs.
		ZFS allows/creates duplicate ACE for different bits for same ID.
		</para>

		<para>Following is the behaviour of Samba for different values :</para>
		<itemizedlist>
		<listitem><para><command>dontcare (default)</command> - copy the ACEs as they come</para></listitem>
		<listitem><para><command>reject (deprecated)</command> - stop operation and exit with error on ACL set op</para></listitem>
		<listitem><para><command>ignore (deprecated)</command> - don't include the second matching ACE</para></listitem>
		<listitem><para><command>merge</command> - bitwise OR the 2 ace.flag fields and 2 ace.mask fields of the 2 duplicate ACEs into 1 ACE</para></listitem>
		</itemizedlist>
		</listitem>
		</varlistentry>


		<varlistentry>
		<term>nfs4:chown = [yes|no]</term>
		<listitem>
		<para>This parameter allows enabling or disabling the chown supported
		by the underlying filesystem. This parameter should be enabled with
		care as it might leave your system insecure.</para>
		<para>Some filesystems allow chown as a) giving b) stealing. It is the latter
		that is considered a risk.</para>

		<para>Following is the behaviour of Samba for different values : </para>
		<itemizedlist>
		<listitem><para><command>yes</command> - Enable chown if as supported by the under filesystem</para></listitem>
		<listitem><para><command>no (default)</command> - Disable chown</para></listitem>
		</itemizedlist>
		</listitem>
		</varlistentry>

		<varlistentry>
		<term>zfsacl:denymissingspecial = [yes|no]</term>
		<listitem>
		<para>Prevent users from setting an ACL that lacks NFSv4 special entries
		(owner@, group@, everyone@). ZFS will automatically generate these these entries
		when calculating the inherited ACL of new files if the ACL of the parent directory
		lacks an inheriting special entry. This may result in user confusion and unexpected
		change in permissions of files and directories as the inherited ACL is generated.</para>
		<itemizedlist>
		<listitem><para><command>yes</command></para></listitem>
		<listitem><para><command>no (default)</command></para></listitem>
		</itemizedlist>
		</listitem>
		</varlistentry>

		<varlistentry>
		<term>zfsacl:block_special = [yes|no]</term>
		<listitem>
		<para>Prevent ZFS from automatically adding NFSv4 special
		entries (owner@, group@, everyone@).  ZFS will automatically
		generate these these entries when calculating the inherited ACL
		of new files if the ACL of the parent directory lacks an
		inheriting special entry. This may result in user confusion and
		unexpected change in permissions of files and directories as the
		inherited ACL is generated. Blocking this behavior is achieved
		by setting an inheriting everyone@ that grants no permissions
		and not adding the entry to the file's Security
		Descriptor</para>
		<itemizedlist>
		<listitem><para><command>yes (default)</command></para></listitem>
		<listitem><para><command>no</command></para></listitem>
		</itemizedlist>
		</listitem>
		</varlistentry>

		<varlistentry>
		<term>zfsacl:map_dacl_protected = [yes|no]</term>
		<listitem>
		<para>If enabled and the ZFS ACL on the underlying filesystem does not contain
		any inherited access control entires, then set the SEC_DESC_DACL_PROTECTED flag
		on the Security Descriptor returned to SMB clients.
		This ensures correct Windows client behavior when disabling inheritance on
		directories.</para>

		<para>Following is the behaviour of Samba for different values : </para>
		<itemizedlist>
		<listitem><para><command>yes</command> - Enable mapping to
		SEC_DESC_DACL_PROTECTED</para></listitem>
		<listitem><para><command>no (default)</command></para></listitem>
		</itemizedlist>
		</listitem>
		</varlistentry>


	</variablelist>
</refsect1>

<refsect1>
	<title>EXAMPLES</title>

	<para>A ZFS mount can be exported via Samba as follows :</para>

<programlisting>
        <smbconfsection name="[samba_zfs_share]"/>
	<smbconfoption name="vfs objects">zfsacl</smbconfoption>
	<smbconfoption name="path">/test/zfs_mount</smbconfoption>
	<smbconfoption name="nfs4: mode">simple</smbconfoption>
	<smbconfoption name="nfs4: acedup">merge</smbconfoption>
</programlisting>
</refsect1>

<refsect1>
	<title>VERSION</title>
	<para>This man page is part of version &doc.version; of the Samba suite.
	</para>
</refsect1>

<refsect1>
	<title>AUTHOR</title>

	<para>The original Samba software and related utilities
	were created by Andrew Tridgell. Samba is now developed
	by the Samba Team as an Open Source project similar
	to the way the Linux kernel is developed.</para>
</refsect1>

</refentry>