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<H1 ALIGN="CENTER">Module mod_access</H1>
<P>
This module is contained in the <CODE>mod_access.c</CODE> file, and
is compiled in by default. It provides access control based on client
hostname or IP address.
</P>

<UL>
<LI><A HREF="#allow">allow</A>
<LI><A HREF="#allowfromenv">allow from env=</A>
<LI><A HREF="#deny">deny</A>
<LI><A HREF="#denyfromenv">deny from env=</A>
<LI><A HREF="#order">order</A>
</UL>
<HR>


<H2><A NAME="allow">allow directive</A></H2>
<P>
<!--%plaintext &lt;?INDEX {\tt allow} directive&gt; -->
<A
 HREF="directive-dict.html#Syntax"
 REL="Help"
><STRONG>Syntax:</STRONG></A> allow from <EM>host host ...</EM><BR>
<A
 HREF="directive-dict.html#Context"
 REL="Help"
><STRONG>Context:</STRONG></A> directory, .htaccess<BR>
<A
 HREF="directive-dict.html#Override"
 REL="Help"
><STRONG>Override:</STRONG></A> Limit<BR>
<A
 HREF="directive-dict.html#Status"
 REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
 HREF="directive-dict.html#Module"
 REL="Help"
><STRONG>Module:</STRONG></A> mod_access
</P>
<P>
The allow directive affects which hosts can access a given directory.
<EM>Host</EM> is one of the following:
</P>
<DL>
<DT><CODE>all</CODE>
<DD>All hosts are allowed access
<DT>A (partial) domain-name
<DD>Hosts whose names match, or end in, this string are allowed access.
<DT>A full IP address
<DD>An IP address of a host allowed access
<DT>A partial IP address
<DD>The first 1 to 3 bytes of an IP address, for subnet restriction.
<DT>A network/netmask pair (<STRONG>Apache 1.3 and later</STRONG>)
<DD>A network a.b.c.d, and a netmask w.x.y.z.  For more fine-grained subnet
    restriction.  (i.e. 10.1.0.0/255.255.0.0)
<DT>A network/nnn CIDR specification (<STRONG>Apache 1.3 and later</STRONG>)
<DD>Similar to the previous case, except the netmask consists of nnn
    high-order 1 bits.  (i.e. 10.1.0.0/16 is the same as 10.1.0.0/255.255.0.0)
</DL>
<P>
Example:
</P>
<BLOCKQUOTE><CODE>allow from .ncsa.uiuc.edu</CODE></BLOCKQUOTE>
<P>
All hosts in the specified domain are allowed access.
</P>
<P>
Note that this compares whole components; <CODE>bar.edu</CODE>
would not match <CODE>foobar.edu</CODE>.
</P>
<P>
See also <A HREF="#deny">deny</A>, <A HREF="#order">order</A>, and
<A HREF="mod_browser.html#browsermatch">BrowserMatch</A>.
</P>

<P>
<A NAME="allowfromenv"><STRONG>Syntax:</STRONG> allow from
 env=<EM>variablename</EM></A><BR>
<A
 HREF="directive-dict.html#Context"
 REL="Help"
><STRONG>Context:</STRONG></A> directory, .htaccess<BR>
<A
 HREF="directive-dict.html#Override"
 REL="Help"
><STRONG>Override:</STRONG></A> Limit<BR>
<A
 HREF="directive-dict.html#Status"
 REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
 HREF="directive-dict.html#Module"
 REL="Help"
><STRONG>Module:</STRONG></A> mod_access<BR>
<A
 HREF="directive-dict.html#Compatibility"
 REL="Help"
><STRONG>Compatibility:</STRONG></A> Apache 1.2 and above
</P>
<P>
The allow from env directive controls access to a directory by the
existence (or non-existence) of an environment variable.
</P>
<P>
Example:
</P>
<BLOCKQUOTE><PRE>
BrowserMatch ^KnockKnock/2.0 let_me_in
&lt;Directory /docroot&gt;
    order deny,allow
    deny from all
    allow from env=let_me_in
&lt;/Directory&gt;
</PRE></BLOCKQUOTE>
In this case browsers with the user-agent string <TT>KnockKnock/2.0</TT> will
be allowed access, and all others will be denied.
<P>
See also <A HREF="#denyfromenv">deny from env</A>
and <A HREF="#order">order</A>.
</P>
<HR>

<H2><A NAME="deny">deny directive</A></H2>
<P>
<!--%plaintext &lt;?INDEX {\tt deny} directive&gt; -->
<A
 HREF="directive-dict.html#Syntax"
 REL="Help"
><STRONG>Syntax:</STRONG></A> deny from <EM>host host ...</EM><BR>
<A
 HREF="directive-dict.html#Context"
 REL="Help"
><STRONG>Context:</STRONG></A> directory, .htaccess<BR>
<A
 HREF="directive-dict.html#Override"
 REL="Help"
><STRONG>Override:</STRONG></A> Limit<BR>
<A
 HREF="directive-dict.html#Status"
 REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
 HREF="directive-dict.html#Module"
 REL="Help"
><STRONG>Module:</STRONG></A> mod_access
</P>
<P>
The deny directive affects which hosts can access a given directory.
<EM>Host</EM> is one of the following:
</P>
<DL>
<DT><CODE>all</CODE>
<DD>all hosts are denied access
<DT>A (partial) domain-name
<DD>host whose name is, or ends in, this string are denied access.
<DT>A full IP address
<DD>An IP address of a host denied access
<DT>A partial IP address
<DD>The first 1 to 3 bytes of an IP address, for subnet restriction.
<DT>A network/netmask pair (<STRONG>Apache 1.3 and later</STRONG>)
<DD>A network a.b.c.d, and a netmask w.x.y.z.  For more fine-grained subnet
    restriction.  (i.e. 10.1.0.0/255.255.0.0)
<DT>A network/nnn CIDR specification (<STRONG>Apache 1.3 and later</STRONG>)
<DD>Similar to the previous case, except the netmask consists of nnn
    high-order 1 bits.  (i.e. 10.1.0.0/16 is the same as 10.1.0.0/255.255.0.0)
</DL>
<P>
Example:
</P>
<BLOCKQUOTE><CODE>deny from 16</CODE></BLOCKQUOTE>
<P>
All hosts in the specified network are denied access.
</P>
<P>
Note that this compares whole components; <CODE>bar.edu</CODE>
would not match <CODE>foobar.edu</CODE>.
</P>
<P>
See also <A HREF="#allow">allow</A> and <A HREF="#order">order</A>.
</P>

<P>
<A NAME="denyfromenv"><STRONG>Syntax:</STRONG> deny from
 env=<EM>variablename</EM></A><BR>
<A
 HREF="directive-dict.html#Context"
 REL="Help"
><STRONG>Context:</STRONG></A> directory, .htaccess<BR>
<A
 HREF="directive-dict.html#Override"
 REL="Help"
><STRONG>Override:</STRONG></A> Limit<BR>
<A
 HREF="directive-dict.html#Status"
 REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
 HREF="directive-dict.html#Module"
 REL="Help"
><STRONG>Module:</STRONG></A> mod_access<BR>
<A
 HREF="directive-dict.html#Compatibility"
 REL="Help"
><STRONG>Compatibility:</STRONG></A> Apache 1.2 and above
</P>
<P>
The deny from env directive controls access to a directory by the
existence (or non-existence) of an environment variable.
</P>
<P>
Example:
</P>
<BLOCKQUOTE><PRE>
BrowserMatch ^BadRobot/0.9 go_away
&lt;Directory /docroot&gt;
    order allow,deny
    allow from all
    deny from env=go_away
&lt;/Directory&gt;
</PRE></BLOCKQUOTE>
In this case browsers with the user-agent string <TT>BadRobot/0.9</TT> will
be denied access, and all others will be allowed.

<P>
See also <A HREF="#allowfromenv">allow from env</A>
and <A HREF="#order">order</A>.
</P>
<HR>

<H2><A NAME="order">order directive</A></H2>
<P>
<!--%plaintext &lt;?INDEX {\tt order} directive&gt; -->
<A
 HREF="directive-dict.html#Syntax"
 REL="Help"
><STRONG>Syntax:</STRONG></A> order <EM>ordering</EM><BR>
<A
 HREF="directive-dict.html#Default"
 REL="Help"
><STRONG>Default:</STRONG></A> <CODE>order deny,allow</CODE><BR>
<A
 HREF="directive-dict.html#Context"
 REL="Help"
><STRONG>Context:</STRONG></A> directory, .htaccess<BR>
<A
 HREF="directive-dict.html#Override"
 REL="Help"
><STRONG>Override:</STRONG></A> Limit<BR>
<A
 HREF="directive-dict.html#Status"
 REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
 HREF="directive-dict.html#Module"
 REL="Help"
><STRONG>Module:</STRONG></A> mod_access
</P>
<P>
The order directive controls the order in which <A HREF="#allow">allow</A> and
<A HREF="#deny">deny</A> directives are evaluated. <EM>Ordering</EM> is one
of
</P>
<DL>
<DT>deny,allow
<DD>the deny directives are evaluated before the allow directives.  (The
initial state is OK.)
<DT>allow,deny
<DD>the allow directives are evaluated before the deny directives.  (The
initial state is FORBIDDEN.)
<DT>mutual-failure
<DD>Only those hosts which appear on the allow list and do not appear
on the deny list are granted access.  (The initial state is irrelevant.)
</DL>
<P>
<STRONG>Note that in all cases every <CODE>allow</CODE> and <CODE>deny</CODE>
statement is evaluated, there is no &quot;short-circuiting&quot;.</STRONG>
</P>
<P>
Example:
</P>
<BLOCKQUOTE><CODE>
    order deny,allow<BR>
    deny from all<BR>
    allow from .ncsa.uiuc.edu<BR>
</CODE></BLOCKQUOTE>
<P>
Hosts in the ncsa.uiuc.edu domain are allowed access; all other hosts are
denied access.
</P>
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