/usr/include/quickfix/fix43/ is in libquickfix-dev 1.13.3+dfsg-4.
This file is owned by root:root, with mode 0o755.
..
/usr/include/quickfix/fix43/Advertisement.h
/usr/include/quickfix/fix43/Allocation.h
/usr/include/quickfix/fix43/AllocationAck.h
/usr/include/quickfix/fix43/BidRequest.h
/usr/include/quickfix/fix43/BidResponse.h
/usr/include/quickfix/fix43/BusinessMessageReject.h
/usr/include/quickfix/fix43/CrossOrderCancelReplaceRequest.h
/usr/include/quickfix/fix43/CrossOrderCancelRequest.h
/usr/include/quickfix/fix43/DerivativeSecurityList.h
/usr/include/quickfix/fix43/DerivativeSecurityListRequest.h
/usr/include/quickfix/fix43/DontKnowTrade.h
/usr/include/quickfix/fix43/Email.h
/usr/include/quickfix/fix43/ExecutionReport.h
/usr/include/quickfix/fix43/Heartbeat.h
/usr/include/quickfix/fix43/IOI.h
/usr/include/quickfix/fix43/ListCancelRequest.h
/usr/include/quickfix/fix43/ListExecute.h
/usr/include/quickfix/fix43/ListStatus.h
/usr/include/quickfix/fix43/ListStatusRequest.h
/usr/include/quickfix/fix43/ListStrikePrice.h
/usr/include/quickfix/fix43/Logon.h
/usr/include/quickfix/fix43/Logout.h
/usr/include/quickfix/fix43/MarketDataIncrementalRefresh.h
/usr/include/quickfix/fix43/MarketDataRequest.h
/usr/include/quickfix/fix43/MarketDataRequestReject.h
/usr/include/quickfix/fix43/MarketDataSnapshotFullRefresh.h
/usr/include/quickfix/fix43/MassQuote.h
/usr/include/quickfix/fix43/MassQuoteAcknowledgement.h
/usr/include/quickfix/fix43/Message.h
/usr/include/quickfix/fix43/MessageCracker.h
/usr/include/quickfix/fix43/MultilegOrderCancelReplaceRequest.h
/usr/include/quickfix/fix43/NewOrderCross.h
/usr/include/quickfix/fix43/NewOrderList.h
/usr/include/quickfix/fix43/NewOrderMultileg.h
/usr/include/quickfix/fix43/NewOrderSingle.h
/usr/include/quickfix/fix43/News.h
/usr/include/quickfix/fix43/OrderCancelReject.h
/usr/include/quickfix/fix43/OrderCancelReplaceRequest.h
/usr/include/quickfix/fix43/OrderCancelRequest.h
/usr/include/quickfix/fix43/OrderMassCancelReport.h
/usr/include/quickfix/fix43/OrderMassCancelRequest.h
/usr/include/quickfix/fix43/OrderMassStatusRequest.h
/usr/include/quickfix/fix43/OrderStatusRequest.h
/usr/include/quickfix/fix43/Quote.h
/usr/include/quickfix/fix43/QuoteCancel.h
/usr/include/quickfix/fix43/QuoteRequest.h
/usr/include/quickfix/fix43/QuoteRequestReject.h
/usr/include/quickfix/fix43/QuoteStatusReport.h
/usr/include/quickfix/fix43/QuoteStatusRequest.h
/usr/include/quickfix/fix43/RFQRequest.h
/usr/include/quickfix/fix43/RegistrationInstructions.h
/usr/include/quickfix/fix43/RegistrationInstructionsResponse.h
/usr/include/quickfix/fix43/Reject.h
/usr/include/quickfix/fix43/ResendRequest.h
/usr/include/quickfix/fix43/SecurityDefinition.h
/usr/include/quickfix/fix43/SecurityDefinitionRequest.h
/usr/include/quickfix/fix43/SecurityList.h
/usr/include/quickfix/fix43/SecurityListRequest.h
/usr/include/quickfix/fix43/SecurityStatus.h
/usr/include/quickfix/fix43/SecurityStatusRequest.h
/usr/include/quickfix/fix43/SecurityTypeRequest.h
/usr/include/quickfix/fix43/SecurityTypes.h
/usr/include/quickfix/fix43/SequenceReset.h
/usr/include/quickfix/fix43/SettlementInstructions.h
/usr/include/quickfix/fix43/TestRequest.h
/usr/include/quickfix/fix43/TradeCaptureReport.h
/usr/include/quickfix/fix43/TradeCaptureReportRequest.h
/usr/include/quickfix/fix43/TradingSessionStatus.h
/usr/include/quickfix/fix43/TradingSessionStatusRequest.h