Commit 5a984846 authored by Stefan Fritsch's avatar Stefan Fritsch
Browse files

Use the new "ap_expr" expression parser. 

The old parser can still be used by setting the new directive
SSILegacyExprParser


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1128614 13f79535-47bb-0310-9956-ffa450edef68
parent 9a599ad0

CHANGES

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Changes with Apache 2.3.13



  *) mod_include: Make the "#if expr" element use the new "ap_expr" expression

     parser. The old parser can still be used by setting the new directive

     SSILegacyExprParser. [Stefan Fritsch]



  *) core: Add some features to ap_expr for use by mod_include: a restricted

     mode that does not allow to bypass request access restrictions; new

     variables DOCUMENT_URI (alias for REQUEST_URI), LAST_MODIFIED; -A as an

STATUS

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@@ -96,8 +96,6 @@ RELEASE SHOWSTOPPERS: 
    jim sez: Why a blocker?, pgollucci +1 jim

    wrowe asks: what's the API change required?



  * mod_includes aught to use ap_expr



  * Clarify/potentially change the meaning of MaxConnections for Event MPM 

    with respect to accepting new connections and keep alive requests for 

    the docs and example config.  This shouldn't change after users and

docs/manual/expr.xml

+33 −26
Changes for docs/manual/expr.xml: 33 added lines, 26 removed lines.
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@@ -354,48 +354,50 @@ listfunction ::= listfuncname "<strong>(</strong>" word "<strong>)</strong>" 
    <table border="1" style="zebra">

    <columnspec><column width=".2"/><column width=".2"/><column width=".6"/></columnspec>



    <tr><th>Name</th><th>Description</th></tr>

    <tr><th>Name</th><th>Description</th><th>Restricted</th></tr>

    <tr><td><code>-d</code></td>

        <td>The argument is treated as a filename.

            True if the file exists and is a directory</td></tr>

            True if the file exists and is a directory</td><td>yes</td></tr>

    <tr><td><code>-e</code></td>

        <td>The argument is treated as a filename.

            True if the file (or dir or special) exists</td></tr>

            True if the file (or dir or special) exists</td><td>yes</td></tr>

    <tr><td><code>-f</code></td>

        <td>The argument is treated as a filename.

            True if the file exists and is regular file</td></tr>

            True if the file exists and is regular file</td><td>yes</td></tr>

    <tr><td><code>-L</code></td>

        <td>The argument is treated as a filename.

            True if the file exists and is symlink</td></tr>

            True if the file exists and is symlink</td><td>yes</td></tr>

    <tr><td><code>-h</code></td>

        <td>The argument is treated as a filename.

            True if the file exists and is symlink

            (same as <code>-L</code>)</td></tr>

            (same as <code>-L</code>)</td><td>yes</td></tr>

    <tr><td><code>-F</code></td>

        <td>True if string is a valid file, accessible via all the server's

            currently-configured access controls for that path. This uses an

            internal subrequest to do the check, so use it with care - it can

            impact your server's performance!</td></tr>

            impact your server's performance!</td><td></td></tr>

    <tr><td><code>-U</code></td>

        <td>True if string is a valid URL, accessible via all the server's

            currently-configured access controls for that path. This uses an

            internal subrequest to do the check, so use it with care - it can

            impact your server's performance!</td></tr>

            impact your server's performance!</td><td></td></tr>

    <tr><td><code>-A</code></td>

        <td>Alias for <code>-U</code></td></tr>

        <td>Alias for <code>-U</code></td><td></td></tr>

    <tr><td><code>-n</code></td>

        <td>True if string is not empty</td></tr>

        <td>True if string is not empty</td><td></td></tr>

    <tr><td><code>-z</code></td>

        <td>True if string is empty</td></tr>

        <td>True if string is empty</td><td></td></tr>

    <tr><td><code>-T</code></td>

        <td>False if string is empty, "<code>0</code>", "<code>off</code>",

            "<code>false</code>", or "<code>no</code>" (case insensitive).

            True otherwise.</td></tr>

            True otherwise.</td><td></td></tr>

    <tr><td><code>-R</code></td>

        <td>Same as "<code>%{REMOTE_ADDR} -ipmatch ...</code>", but more efficient

        </td></tr>

        </td><td></td></tr>

    </table>



    <p>The operators marked as "restricted" are not available in some modules

    like <module>mod_include</module>.</p>

</section>



<section id="functions">
@@ -408,35 +410,40 @@ listfunction ::= listfuncname "<strong>(</strong>" word "<strong>)</strong>" 
    <table border="1" style="zebra">

    <columnspec><column width=".2"/><column width=".8"/></columnspec>



    <tr><th>Name</th><th>Description</th></tr>

    <tr><th>Name</th><th>Description</th><th>Restricted</th></tr>

    <tr><td><code>req</code>, <code>http</code></td>

        <td>Get HTTP request header</td></tr>

        <td>Get HTTP request header</td><td></td></tr>

    <tr><td><code>resp</code></td>

        <td>Get HTTP response header</td></tr>

        <td>Get HTTP response header</td><td></td></tr>

    <tr><td><code>reqenv</code></td>

        <td>Lookup request environment variable</td></tr>

        <td>Lookup request environment variable</td><td></td></tr>

    <tr><td><code>osenv</code></td>

        <td>Lookup operating system environment variable</td></tr>

        <td>Lookup operating system environment variable</td><td></td></tr>

    <tr><td><code>note</code></td>

        <td>Lookup request note</td></tr>

        <td>Lookup request note</td><td></td></tr>

    <tr><td><code>env</code></td>

        <td>Return first match of <code>note</code>, <code>reqenv</code>,

            <code>osenv</code></td></tr>

            <code>osenv</code></td><td></td></tr>

    <tr><td><code>tolower</code></td>

        <td>Convert string to lower case</td></tr>

        <td>Convert string to lower case</td><td></td></tr>

    <tr><td><code>toupper</code></td>

        <td>Convert string to uppser case</td></tr>

        <td>Convert string to uppser case</td><td></td></tr>

    <tr><td><code>escape</code></td>

        <td>Escape special characters in %hex encoding</td></tr>

        <td>Escape special characters in %hex encoding</td><td></td></tr>

    <tr><td><code>unescape</code></td>

        <td>Unescape %hex encoded string, leaving URL-special characters encoded (XXX: describe better)</td></tr>

        <td>Unescape %hex encoded string, leaving URL-special characters

            encoded (XXX: describe better)</td><td></td></tr>

    <tr><td><code>file</code></td>

        <td>Read contents from a file</td></tr>

        <td>Read contents from a file</td><td>yes</td></tr>

    <tr><td><code>filesize</code></td>

        <td>Return size of a file (or 0 if file does not exist or is not regular file)</td></tr>

        <td>Return size of a file (or 0 if file does not exist or is not

            regular file)</td><td>yes</td></tr>



    </table>



    <p>The functions marked as "restricted" are not available in some modules

    like <module>mod_include</module>.</p>



    <p>In addition to string-valued functions, there are also list-valued functions which

    take one string as argument and return a wordlist, i.e. a list of strings. The wordlist

    can be used with the special <code>-in</code> operator.

docs/manual/howto/ssi.xml

+2 −1
Changes for docs/manual/howto/ssi.xml: 2 added lines, 1 removed line.
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@@ -448,7 +448,8 @@ modified?</title> 
    <p>Then, in your SSI-enabled document, you might do the

    following:</p>

<example>

        &lt;!--#if expr="${Mac} &amp;&amp; ${InternetExplorer}" --&gt;<br />

        &lt;!--#if expr="-T reqenv('Mac') &amp;&amp;

                         -T reqenv('InternetExplorer')" --&gt;<br />

        Apologetic text goes here<br />

        &lt;!--#else --&gt;<br />

        Cool JavaScript code goes here<br />

docs/manual/mod/mod_include.xml

+79 −31
Changes for docs/manual/mod/mod_include.xml: 79 added lines, 31 removed lines.
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@@ -504,12 +504,14 @@ 
    directive. This includes the <code>config</code>,

    <code>exec</code>, <code>flastmod</code>, <code>fsize</code>,

    <code>include</code>, <code>echo</code>, and <code>set</code>

    directives, as well as the arguments to conditional operators.

    directives. If <directive module="mod_include"

    >SSILegacyExprParser</directive> is set to <code>on</code>,

    substitution also occures in the arguments to conditional operators.

    You can insert a literal dollar sign into the string using backslash

    quoting:</p>



    <example>

      &lt;!--#if expr="$a = \$test" --&gt;

      &lt;!--#set var="cur" value="\$test" --&gt;

    </example>



    <p>If a variable reference needs to be substituted in the
@@ -526,26 +528,6 @@ 
    to "<code>X_Y</code>" if <code>REMOTE_HOST</code> is

    "<code>X</code>" and <code>REQUEST_METHOD</code> is

    "<code>Y</code>".</p>



    <p>The below example will print "in foo" if the

    <code>DOCUMENT_URI</code> is <code>/foo/file.html</code>, "in bar"

    if it is <code>/bar/file.html</code> and "in neither" otherwise:</p>



    <example>

      &lt;!--#if expr='"$DOCUMENT_URI" = "/foo/file.html"' --&gt;<br />

      <indent>

        in foo<br />

      </indent>

      &lt;!--#elif expr='"$DOCUMENT_URI" = "/bar/file.html"' --&gt;<br />

      <indent>

        in bar<br />

      </indent>

      &lt;!--#else --&gt;<br />

      <indent>

        in neither<br />

      </indent>

      &lt;!--#endif --&gt;

    </example>

</section>



<section id="flowctrl">
@@ -573,7 +555,55 @@ 
    <p>The <code>endif</code> element ends the <code>if</code> element

    and is required.</p>



    <p><var>test_condition</var> is one of the following:</p>

    <p><var>test_condition</var> is a boolean expression tha follows the

    <a href="../expr.html">ap_expr</a> syntax. The syntax can be changed

    to be compatible with Apache HTTPD 2.2.x using <directive

    module="mod_include">SSILegacyExprParser</directive>.</p>



    <p>The SSI variables set with the <code>var</code> element are exported

    into the request environment and can be accessed with the

    <code>reqenv</code> function. As a short-cut, the function name

    <code>v</code> is also available inside <module>mod_include</module>.</p>



    <p>The below example will print "from local net" if client IP address

    belongs to the 10.0.0.0/8 subnet.</p>



    <example>

      &lt;!--#if expr='-R "10.0.0.0/8"' --&gt;<br />

      <indent>

        from local net<br />

      </indent>

      &lt;!--#else --&gt;<br />

      <indent>

        from somewhere else<br />

      </indent>

      &lt;!--#endif --&gt;

    </example>



    <p>The below example will print "foo is bar" if the variable

    <code>foo</code> is set to the value "bar".</p>



    <example>

      &lt;!--#if expr='v("foo") = "bar"' --&gt;<br />

      <indent>

        foo is bar<br />

      </indent>

      &lt;!--#endif --&gt;

    </example>



    <note><title>Reference Documentation</title>

    <p>See also: <a href="../expr.html">Expressions in Apache HTTP Server</a>,

    for a complete reference and examples. The <em>restricted</em> functions

    are not available inside <module>mod_include</module></p>

    </note>

</section>



<section id="legacyexpr">

    <title>Legacy expression syntax</title>



    <p>This section describes the syntax of the <code>#if expr</code>

    element if <directive module="mod_include">SSILegacyExprParser</directive>

    is set to <code>on</code>.</p>



    <dl>

      <dt><code><var>string</var></code></dt>
@@ -713,12 +743,6 @@ 
     be escaped.  This is regardless of their meaning to the regex engine.</p>

    </note>



    <!-- mod_include does not use ap_expr, yet

    <note><title>Reference Documentation</title>

    <p>See also: <a href="../expr.html">Expressions in Apache HTTP Server</a>,

    for a complete reference and examples.</p>

    </note>

    -->

</section>



<directivesynopsis>
@@ -856,14 +880,20 @@ displayed</description> 


<directivesynopsis>

<name>SSIAccessEnable</name>

<description>Enable the -A flag during conditional flow control processing.</description>

<description>Enable the -A flag in legacy conditional expressions.</description>

<syntax>SSIAccessEnable on|off</syntax>

<default>SSIAccessEnable off</default>

<contextlist><context>directory</context><context>.htaccess</context></contextlist>



<usage>

    <note><directive>SSIAccessEnable</directive> has no effect unless

    <directive module="mod_include">SSILegacyExprParser</directive> is set to

    <code>on</code>.

    </note>



    <p>The <directive>SSIAccessEnable</directive> directive controls whether

    the -A test is enabled during conditional flow control processing.

    the -A test is enabled during conditional flow control processing when

    using the 2.2.x compatible expression parser.

    <directive>SSIAccessEnable</directive> can take on the following values:</p>



    <dl>
@@ -962,6 +992,24 @@ server.</description> 
</usage>

</directivesynopsis>



<directivesynopsis>

<name>SSILegacyExprParser</name>

<description>Enable compatibility mode for conditional expressions.</description>

<syntax>SSILegacyExprParser on|off</syntax>

<default>SSILegacyExprParser off</default>

<contextlist><context>directory</context><context>.htaccess</context></contextlist>

<compatibility>Available in version 2.3.13 and later.</compatibility>



<usage>

    <p>As of version 2.3.13, <module>mod_include</module> has switched to the

    new <a href="../expr.html">ap_expr</a> syntax for conditional expressions

    in <code>#if</code> flow control elements.  This directive allows to

    switch to the <a href="#legacyexpr">old syntax</a> which is compatible

    with Apache HTTPD version 2.2.x and earlier. 

    </p>

</usage>

</directivesynopsis>



<directivesynopsis>

<name>XBitHack</name>

<description>Parse SSI directives in files with the execute bit