SYNOPSIS |
#include <dkim.h>
void dkim_dns_set_query_start(
DKIM_LIB *libopendkim,
int (*func)(void *, int, u_char *, u_char *, size_t,
void **)
);
Declares the function to be used by a libopendkim instance when it needs to
start a DNS query. By default, a stub function that calls the standard
UNIX resolver library is set.
The function will be passed the following arguments:
- An opaque DNS service handle as previously specified by a call to
dkim_dns_set_query_service()
- The DNS query type (e.g., ns_t_txt or the older T_TXT)
- A NULL-terminated string containing the name to be queried
- The address of a buffer into which the result should be written
- The length of that buffer
- The address of a void * that should be updated to contain an
opaque handle for the started query
The function is expected to return one of the following:
- DKIM_DNS_SUCCESS -- query was successfully initiated
- DKIM_DNS_ERROR -- an error occurred
The query type should be a DNS resource record type as registered with
IANA (here).
The constants are typically given names for use in source code via the
include file <arpa/nameser.h>.
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