| SYNOPSIS | 
#include <dkim.h>
int dkim_dns_set_init(
	DKIM_LIB *libopendkim,
        int (*func)(void **)
);
Declares the function to be used by a libopendkim instance when it needs to
initialize a DNS resolver.  By default, a stub function that initializes
the standard system resolver is set.  
The function will be passed the following arguments:
 
 -  A pointer to a handle that will be updated to refer to the instantiated
      resolver service.  The procedure is equivalent to instantiating
      a resolver service and then passing a pointer representing that
      service to
      dkim_dns_set_query_service().
  
The function is expected to return one of the following:
 - DKIM_DNS_SUCCESS -- the resolver was initialized successfully
 
 - DKIM_DNS_ERROR -- an error occurred
  
 | 
| DESCRIPTION | 
| Called When | 
dkim_dns_set_init() can be called at any time, but is
presumably most useful prior to doing any DNS operations such as are done
during dkim_eoh() when verifying.  The
function will be called implicitly if no service handle has been stored
and a query is ready to be started.  | 
 
 
 | 
|---|
| ARGUMENTS | 
    
    | Argument | Description |  
    | libopendkim | 
	The library instantiation handle, returned by
        dkim_init().
	 |  
    | func | 
	A pointer to a function that should be used to instantiate
	a DNS resolver.  If NULL, no initialization function will be called.
	 |  
     
 | 
| RETURN VALUES |  
- DKIM_DNS_SUCCESS -- successful operation
 - DKIM_DNS_ERROR -- an error occurred
  
 | 
| NOTES |  
 |