ares_mkquery - Compose a single-question DNS query buffer
#include <ares.h>
int ares_mkquery(const char *name, int dnsclass, int type,
unsigned short id, int rd, char **buf,
int *buflen)
The ares_mkquery function composes a DNS query with a single question.
The parameter name gives the query name as a NUL-terminated C string of
period-separated labels optionally ending with a period; periods and
backslashes within a label must be escaped with a backlash. The parameters
dnsclass and type give the class and type of the query using the
values defined in <arpa/nameser.h>. The parameter id gives
a 16-bit identifier for the query. The parameter rd should be nonzero
if recursion is desired, zero if not. The query will be placed in an allocated
buffer, a pointer to which will be stored in the variable pointed to by
buf, and the length of which will be stored in the variable pointed to
by buflen. It is the caller's responsibility to free this buffer using
ares_free_string when it is no longer needed.
ares_mkquery can return any of the following values:
- ARES_SUCCESS
- Construction of the DNS query succeeded.
- ARES_EBADNAME
- The query name name could not be encoded as a domain name, either
because it contained a zero-length label or because it contained a label
of more than 63 characters.
- ARES_ENOMEM
- Memory was exhausted.
ares_expand_name(3), ares_free_string(3)
Greg Hudson, MIT Information Systems
Copyright 1998, 2000 by the Massachusetts Institute of Technology.