func recoverBPFState()

in pkg/ebpf/bpf_client.go [379:487]
91 lines of code
27 McCabe index (conditional complexity)

func recoverBPFState(bpfTCClient tc.BpfTc, eBPFSDKClient goelf.BpfSDKClient, policyEndpointeBPFContext *sync.Map, globalMaps *sync.Map, updateIngressProbe,
	updateEgressProbe, updateEventsProbe bool) (bool, bool, int, map[string]string, map[string]string, error) {
	log := ctrl.Log.WithName("ebpf-client") //TODO reuse logger
	isConntrackMapPresent, isPolicyEventsMapPresent := false, false
	eventsMapFD := 0
	var interfaceNametoIngressPinPath = make(map[string]string)
	var interfaceNametoEgressPinPath = make(map[string]string)

	// Recover global maps (Conntrack and Events) if there is no need to update
	// events binary
	if !updateEventsProbe {
		recoveredGlobalMaps, err := eBPFSDKClient.RecoverGlobalMaps()
		if err != nil {
			log.Error(err, "failed to recover global maps..")
			sdkAPIErr.WithLabelValues("RecoverGlobalMaps").Inc()
			return isConntrackMapPresent, isPolicyEventsMapPresent, eventsMapFD, interfaceNametoIngressPinPath, interfaceNametoEgressPinPath, nil
		}
		log.Info("Total no.of  global maps recovered...", "count: ", len(recoveredGlobalMaps))
		for globalMapName, globalMap := range recoveredGlobalMaps {
			log.Info("Global Map..", "Name: ", globalMapName, "updateEventsProbe: ", updateEventsProbe)
			if globalMapName == CONNTRACK_MAP_PIN_PATH {
				log.Info("Conntrack Map is already present on the node")
				isConntrackMapPresent = true
				globalMaps.Store(globalMapName, globalMap)
			}
			if globalMapName == POLICY_EVENTS_MAP_PIN_PATH {
				isPolicyEventsMapPresent = true
				eventsMapFD = int(globalMap.MapFD)
				log.Info("Policy event Map is already present on the node ", "Recovered FD", eventsMapFD)
			}
		}
	}

	// If no updates required to probes, Recover BPF Programs and Maps from BPF_FS. We only aim to recover programs and maps
	// created by aws-network-policy-agent (Located under /sys/fs/bpf/globals/aws)
	if !updateIngressProbe || !updateEgressProbe {
		bpfState, err := eBPFSDKClient.RecoverAllBpfProgramsAndMaps()
		var peBPFContext BPFContext
		if err != nil {
			//Log it and move on. We will overwrite and recreate the maps/programs
			log.Info("BPF State Recovery failed: ", "error: ", err)
			sdkAPIErr.WithLabelValues("RecoverAllBpfProgramAndMaps").Inc()
		}

		log.Info("Number of probes/maps recovered - ", "count: ", len(bpfState))
		for pinPath, bpfEntry := range bpfState {
			log.Info("Recovered program Identifier: ", "Pin Path: ", pinPath)
			podIdentifier, direction := utils.GetPodIdentifierFromBPFPinPath(pinPath)
			log.Info("PinPath: ", "podIdentifier: ", podIdentifier, "direction: ", direction)
			value, ok := policyEndpointeBPFContext.Load(podIdentifier)
			if ok {
				peBPFContext = value.(BPFContext)
			}
			if direction == "ingress" && !updateIngressProbe {
				peBPFContext.ingressPgmInfo = bpfEntry
			} else if direction == "egress" && !updateEgressProbe {
				peBPFContext.egressPgmInfo = bpfEntry
			}
			policyEndpointeBPFContext.Store(podIdentifier, peBPFContext)
		}
	}

	//If update required, cleanup probes and gather data to re attach probes with new programs
	if updateIngressProbe || updateEgressProbe {
		// Get all loaded programs and maps
		bpfState, err := eBPFSDKClient.GetAllBpfProgramsAndMaps()
		if err != nil {
			log.Info("GetAllBpfProgramsAndMaps failed: ", "error: ", err)
			sdkAPIErr.WithLabelValues("GetAllBpfProgramsAndMaps").Inc()
			return isConntrackMapPresent, isPolicyEventsMapPresent, eventsMapFD, interfaceNametoIngressPinPath, interfaceNametoEgressPinPath, err
		}
		log.Info("GetAllBpfProgramsAndMaps ", "returned", len(bpfState))
		progIdToPinPath := make(map[int]string)
		for pinPath, bpfData := range bpfState {
			progId := bpfData.Program.ProgID
			if progId > 0 {
				progIdToPinPath[progId] = pinPath
			}
		}

		// Get attached progIds
		interfaceToIngressProgIds, interfaceToEgressProgIds, err := bpfTCClient.GetAllAttachedProgIds()
		log.Info("Got attached ", "ingressprogIds ", len(interfaceToIngressProgIds), " egressprogIds ", len(interfaceToEgressProgIds))

		//cleanup all existing filters
		cleanupErr := bpfTCClient.CleanupQdiscs(updateIngressProbe, updateEgressProbe)
		if cleanupErr != nil {
			// log the error and continue. Attaching new probes will cleanup the old ones
			log.Info("Probe cleanup failed ", "error: ", cleanupErr)
			sdkAPIErr.WithLabelValues("CleanupQdiscs").Inc()
		}

		for interfaceName, existingIngressProgId := range interfaceToIngressProgIds {
			pinPath, ok := progIdToPinPath[existingIngressProgId]
			if ok && updateIngressProbe {
				interfaceNametoIngressPinPath[interfaceName] = pinPath
			}
		}
		for interfaceName, existingEgressProgId := range interfaceToEgressProgIds {
			pinPath, ok := progIdToPinPath[existingEgressProgId]
			if ok && updateEgressProbe {
				interfaceNametoEgressPinPath[interfaceName] = pinPath
			}
		}
		log.Info("Collected all data for reattaching probes")
	}

	return isConntrackMapPresent, isPolicyEventsMapPresent, eventsMapFD, interfaceNametoIngressPinPath, interfaceNametoEgressPinPath, nil
}