ares_mkquery - Compose a single-question DNS query buffer
int ares_mkquery(const char *name, int dnsclass, int type,
unsigned short id, int rd, char **buf,
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.
Greg Hudson, MIT Information Systems
Copyright 1998, 2000 by the Massachusetts Institute of Technology.
4 January 2000