/usr/include/libktorrent/peer/ is in libktorrent-dev 1.3.1-3ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libktorrent/peer/accessmanager.h
/usr/include/libktorrent/peer/authenticate.h
/usr/include/libktorrent/peer/authenticatebase.h
/usr/include/libktorrent/peer/authenticationmonitor.h
/usr/include/libktorrent/peer/chunkcounter.h
/usr/include/libktorrent/peer/connectionlimit.h
/usr/include/libktorrent/peer/packetreader.h
/usr/include/libktorrent/peer/peer.h
/usr/include/libktorrent/peer/peerconnector.h
/usr/include/libktorrent/peer/peerdownloader.h
/usr/include/libktorrent/peer/peerid.h
/usr/include/libktorrent/peer/peermanager.h
/usr/include/libktorrent/peer/peerprotocolextension.h
/usr/include/libktorrent/peer/peeruploader.h
/usr/include/libktorrent/peer/serverauthenticate.h
/usr/include/libktorrent/peer/superseeder.h
/usr/include/libktorrent/peer/utmetadata.h
/usr/include/libktorrent/peer/utpex.h