/usr/include/rutil/dns/ is in libresiprocate-1.11-dev 1:1.11.0~beta5-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/rutil/dns/AresCompat.hxx
/usr/include/rutil/dns/AresDns.hxx
/usr/include/rutil/dns/DnsAAAARecord.hxx
/usr/include/rutil/dns/DnsCnameRecord.hxx
/usr/include/rutil/dns/DnsHandler.hxx
/usr/include/rutil/dns/DnsHostRecord.hxx
/usr/include/rutil/dns/DnsNaptrRecord.hxx
/usr/include/rutil/dns/DnsResourceRecord.hxx
/usr/include/rutil/dns/DnsSrvRecord.hxx
/usr/include/rutil/dns/DnsStub.hxx
/usr/include/rutil/dns/ExternalDns.hxx
/usr/include/rutil/dns/ExternalDnsFactory.hxx
/usr/include/rutil/dns/LocalDns.hxx
/usr/include/rutil/dns/QueryTypes.hxx
/usr/include/rutil/dns/RRCache.hxx
/usr/include/rutil/dns/RRFactory.hxx
/usr/include/rutil/dns/RRList.hxx
/usr/include/rutil/dns/RROverlay.hxx
/usr/include/rutil/dns/RRVip.hxx