| SYNOPSIS | 
#include <dkim.h>
DKIM_STAT dkim_set_policy_lookup(
	DKIM_LIB *libopendkim,
        DKIM_CBSTAT (*func) (DKIM *dkim,
	             unsigned char *query,
                     _Bool excheck,
	             unsigned char *buf,
	             size_t buflen,
	             int *qstat)
);
Defines a function which should do policy lookups rather than implementing
the DKIM specification (e.g a DNS lookup). | 
|---|
| ARGUMENTS | 
    | Argument | Description | 
|---|
 | libopendkim | Library-specific handle, returned by
        dkim_init(). |  | func | 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: 
	 The function should return a valid
	DKIM_CBSTAT constant; in
	particular, if no policy is found, the contents of buf
	should be unchanged and DKIM_CBSTAT_CONTINUE should be
	returned.  If func is NULL, the internal policy lookup
	implementation will be used. a DKIM handle referencing the
	      job being processed;
	  a pointer to the string that should be queried
	  a Boolean indicating whether this query should verify domain
	      existence ("true") or retrieve the policy TXT record ("false")
	  a pointer to a buffer that should receive the result of the
	      policy lookup
	  the number of bytes available there
	  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. NXDOMAIN,
	      NOERROR, SERVFAIL, etc., typically defined
	      in <arpa/nameser.h>)
	 |  | 
|---|