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<head><title>dkim_set_policy_lookup()</title></head>
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<h1>dkim_set_policy_lookup()</h1>
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<!---------- Synopsis ----------->
<tr><th valign="top" align=left width=150>SYNOPSIS</th><td>
<pre>
#include <dkim.h>
<a href="dkim_stat.html"><tt>DKIM_STAT</tt></a> dkim_set_policy_lookup(
<a href="dkim_lib.html"><tt>DKIM_LIB</tt></a> *libopendkim,
<a href="dkim_cbstat.html"><tt>DKIM_CBSTAT</tt></a> (*func) (<a href="dkim.html"><tt>DKIM</tt></a> *dkim,
unsigned char *query,
_Bool excheck,
unsigned char *buf,
size_t buflen,
int *qstat)
);
</pre>
Defines a function which should do policy lookups rather than implementing
the DKIM specification (e.g a DNS lookup).
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<!----------- Description ---------->
<tr><th valign="top" align=left>DESCRIPTION</th><td>
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<tr align="left" valign=top>
<th width="80">Called When</th>
<td><tt>dkim_set_policy_lookup()</tt> can be called at any time.</td>
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<!----------- Arguments ---------->
<tr><th valign="top" align=left>ARGUMENTS</th><td>
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<tr bgcolor="#dddddd"><th>Argument</th><th>Description</th></tr>
<tr valign="top"><td>libopendkim</td>
<td>Library-specific handle, returned by
<a href="dkim_init.html"><tt>dkim_init()</tt></a>.
</td></tr>
<tr valign="top"><td>func</td>
<td>A pointer to a function which the library should use in place
of its own code to do policy lookups. The function will receive
six things:
<ol>
<li> a <a href="dkim.html"><tt>DKIM</tt></a> handle referencing the
job being processed;
<li> a pointer to the string that should be queried
<li> a Boolean indicating whether this query should verify domain
existence ("true") or retrieve the policy TXT record ("false")
<li> a pointer to a buffer that should receive the result of the
policy lookup
<li> the number of bytes available there
<li> a pointer to an integer which should receive the result of
the query attempt, and should be one of the known constants
used to report the status of a DNS query (e.g. <tt>NXDOMAIN</tt>,
<tt>NOERROR</tt>, <tt>SERVFAIL</tt>, etc., typically defined
in <tt><arpa/nameser.h></tt>)
</ol>
The function should return a valid
<a href="dkim_cbstat.html"><tt>DKIM_CBSTAT</tt></a> constant; in
particular, if no policy is found, the contents of <tt>buf</tt>
should be unchanged and <tt>DKIM_CBSTAT_CONTINUE</tt> should be
returned. If <tt>func</tt> is NULL, the internal policy lookup
implementation will be used. </td></tr>
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<!----------- Return Value ---------->
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<th valign="top" align=left>RETURN VALUES</th>
<td>
<ul>
<li>DKIM_STAT_OK -- success
</ul>
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<!----------- Notes ---------->
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<th valign="top" align=left>NOTES</th>
<td>
<ul>
<li>None.
</ul>
</td>
</tr>
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Copyright (c) 2007, 2008 Sendmail, Inc. and its suppliers.
All rights reserved.
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Copyright (c) 2009-2011, The OpenDKIM Project. All rights reserved.
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By using this file, you agree to the terms and conditions set
forth in the respective licenses.
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