Debugging interfaces: p_*, fp_*, and sym_* could conceivably be
used to produce debug out, but these functions have not been
updated to parse more resource records, so they are not very useful
today. Likewise for ns_sprintrr and ns_sprintrrf. ns_format_ttl and
ns_parse_ttl are related to these.
Internal implementation details: res_isourserver is probably only
useful in the implementation of a stub resolver, and so is
res_nameinquery.
Unclear semantics and bad performance: ns_samedomain, ns_subdomain,
ns_makecanon, ns_samename do textual converions & copies instead of
checking equivalence of the wire format.
inet_neta cannot handle IPv6 addresses.
res_hostalias has been superseded by getaddrinfo with AI_CANONNAME.
hostalias is not thread-safe.
Some functions have int as size arguments instead of size_t, so they
do not follow current coding practices. However, dn_expand and
b64_ntop are somewhat widely used (to name just two examples), so
deprecating them seems problematic.
Reviewed-by: Carlos O'Donell <carlos@systemhalted.org>
