/usr/include/Swiften/LinkLocal/DNSSD/ is in libswiften-dev 2.0+dev6-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/Swiften/LinkLocal/DNSSD/Avahi/
/usr/include/Swiften/LinkLocal/DNSSD/Avahi/AvahiBrowseQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Avahi/AvahiQuerier.h
/usr/include/Swiften/LinkLocal/DNSSD/Avahi/AvahiQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Avahi/AvahiRegisterQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Avahi/AvahiResolveHostnameQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Avahi/AvahiResolveServiceQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Bonjour/
/usr/include/Swiften/LinkLocal/DNSSD/Bonjour/BonjourBrowseQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Bonjour/BonjourQuerier.h
/usr/include/Swiften/LinkLocal/DNSSD/Bonjour/BonjourQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Bonjour/BonjourRegisterQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Bonjour/BonjourResolveHostnameQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Bonjour/BonjourResolveServiceQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/DNSSDBrowseQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/DNSSDQuerier.h
/usr/include/Swiften/LinkLocal/DNSSD/DNSSDRegisterQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/DNSSDResolveHostnameQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/DNSSDResolveServiceQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/DNSSDServiceID.h
/usr/include/Swiften/LinkLocal/DNSSD/Fake/
/usr/include/Swiften/LinkLocal/DNSSD/Fake/FakeDNSSDBrowseQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Fake/FakeDNSSDQuerier.h
/usr/include/Swiften/LinkLocal/DNSSD/Fake/FakeDNSSDQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Fake/FakeDNSSDRegisterQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Fake/FakeDNSSDResolveHostnameQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/Fake/FakeDNSSDResolveServiceQuery.h
/usr/include/Swiften/LinkLocal/DNSSD/PlatformDNSSDQuerierFactory.h