// SPDX-License-Identifier: Apache-2.0
// Copyright Authors of Cilium

package option

import (
	"bytes"
	"crypto/sha256"
	"encoding/json"
	"fmt"
	"log/slog"
	"math"
	"net"
	"net/netip"
	"os"
	"path/filepath"
	"regexp"
	"runtime"
	"slices"
	"strconv"
	"strings"
	"unicode"
	"unicode/utf8"

	"github.com/cilium/ebpf"
	"github.com/google/go-cmp/cmp"
	"github.com/google/go-cmp/cmp/cmpopts"
	"github.com/mackerelio/go-osstat/memory"
	"github.com/spf13/cast"
	"github.com/spf13/cobra"
	"github.com/spf13/pflag"
	"github.com/spf13/viper"

	"github.com/cilium/cilium/api/v1/models"
	"github.com/cilium/cilium/pkg/cidr"
	clustermeshTypes "github.com/cilium/cilium/pkg/clustermesh/types"
	"github.com/cilium/cilium/pkg/command"
	"github.com/cilium/cilium/pkg/defaults"
	"github.com/cilium/cilium/pkg/ip"
	ipamOption "github.com/cilium/cilium/pkg/ipam/option"
	"github.com/cilium/cilium/pkg/kpr"
	"github.com/cilium/cilium/pkg/logging"
	"github.com/cilium/cilium/pkg/logging/logfields"
	"github.com/cilium/cilium/pkg/time"
	"github.com/cilium/cilium/pkg/util"
	"github.com/cilium/cilium/pkg/version"
)

const (
	// AgentHealthPort is the TCP port for agent health status API
	AgentHealthPort = "agent-health-port"

	// ClusterHealthPort is the TCP port for cluster-wide network connectivity health API
	ClusterHealthPort = "cluster-health-port"

	// ClusterMeshHealthPort is the TCP port for ClusterMesh apiserver health API
	ClusterMeshHealthPort = "clustermesh-health-port"

	// AllowICMPFragNeeded allows ICMP Fragmentation Needed type packets in policy.
	AllowICMPFragNeeded = "allow-icmp-frag-needed"

	// AllowLocalhost is the policy when to allow local stack to reach local endpoints { auto | always | policy }
	AllowLocalhost = "allow-localhost"

	// AllowLocalhostAuto defaults to policy except when running in
	// Kubernetes where it then defaults to "always"
	AllowLocalhostAuto = "auto"

	// AllowLocalhostAlways always allows the local stack to reach local
	// endpoints
	AllowLocalhostAlways = "always"

	// AllowLocalhostPolicy requires a policy rule to allow the local stack
	// to reach particular endpoints or policy enforcement must be
	// disabled.
	AllowLocalhostPolicy = "policy"

	// AnnotateK8sNode enables annotating a kubernetes node while bootstrapping
	// the daemon, which can also be disabled using this option.
	AnnotateK8sNode = "annotate-k8s-node"

	// BPFDistributedLRU enables per-CPU distributed backend memory
	BPFDistributedLRU = "bpf-distributed-lru"

	// BPFRoot is the Path to BPF filesystem
	BPFRoot = "bpf-root"

	// CGroupRoot is the path to Cgroup2 filesystem
	CGroupRoot = "cgroup-root"

	// ConfigFile is the Configuration file (default "$HOME/ciliumd.yaml")
	ConfigFile = "config"

	// ConfigDir is the directory that contains a file for each option where
	// the filename represents the option name and the content of that file
	// represents the value of that option.
	ConfigDir = "config-dir"

	// ConntrackGCInterval is the name of the ConntrackGCInterval option
	ConntrackGCInterval = "conntrack-gc-interval"

	// ConntrackGCMaxInterval is the name of the ConntrackGCMaxInterval option
	ConntrackGCMaxInterval = "conntrack-gc-max-interval"

	// DebugArg is the argument enables debugging mode
	DebugArg = "debug"

	// DebugVerbose is the argument enables verbose log message for particular subsystems
	DebugVerbose = "debug-verbose"

	// Devices facing cluster/external network for attaching bpf_host
	Devices = "devices"

	// Forces the auto-detection of devices, even if specific devices are explicitly listed
	ForceDeviceDetection = "force-device-detection"

	// DirectRoutingDevice is the name of a device used to connect nodes in
	// direct routing mode (only required by BPF NodePort)
	DirectRoutingDevice = "direct-routing-device"

	// EnablePolicy enables policy enforcement in the agent.
	EnablePolicy = "enable-policy"

	// EnableL7Proxy is the name of the option to enable L7 proxy
	EnableL7Proxy = "enable-l7-proxy"

	// EnableTracing enables tracing mode in the agent.
	EnableTracing = "enable-tracing"

	// EnableIPIPTermination is the name of the option to enable IPIP termination
	EnableIPIPTermination = "enable-ipip-termination"

	// Add unreachable routes on pod deletion
	EnableUnreachableRoutes = "enable-unreachable-routes"

	// EncryptInterface enables encryption on specified interface
	EncryptInterface = "encrypt-interface"

	// EncryptNode enables node IP encryption
	EncryptNode = "encrypt-node"

	// GopsPort is the TCP port for the gops server.
	GopsPort = "gops-port"

	// EnableGops run the gops server
	EnableGops = "enable-gops"

	// FixedIdentityMapping is the key-value for the fixed identity mapping
	// which allows to use reserved label for fixed identities
	FixedIdentityMapping = "fixed-identity-mapping"

	// FixedZoneMapping is the key-value for the fixed zone mapping which
	// is used to map zone value (string) from EndpointSlice to ID (uint8)
	// in lb{4,6}_backend in BPF map.
	FixedZoneMapping = "fixed-zone-mapping"

	// IPv4Range is the per-node IPv4 endpoint prefix, e.g. 10.16.0.0/16
	IPv4Range = "ipv4-range"

	// IPv6Range is the per-node IPv6 endpoint prefix, must be /96, e.g. fd02:1:1::/96
	IPv6Range = "ipv6-range"

	// IPv4ServiceRange is the Kubernetes IPv4 services CIDR if not inside cluster prefix
	IPv4ServiceRange = "ipv4-service-range"

	// IPv6ServiceRange is the Kubernetes IPv6 services CIDR if not inside cluster prefix
	IPv6ServiceRange = "ipv6-service-range"

	// IPv6ClusterAllocCIDRName is the name of the IPv6ClusterAllocCIDR option
	IPv6ClusterAllocCIDRName = "ipv6-cluster-alloc-cidr"

	// K8sRequireIPv4PodCIDRName is the name of the K8sRequireIPv4PodCIDR option
	K8sRequireIPv4PodCIDRName = "k8s-require-ipv4-pod-cidr"

	// K8sRequireIPv6PodCIDRName is the name of the K8sRequireIPv6PodCIDR option
	K8sRequireIPv6PodCIDRName = "k8s-require-ipv6-pod-cidr"

	// EnableK8s operation of Kubernetes-related services/controllers.
	// Intended for operating cilium with CNI-compatible orchestrators other than Kubernetes. (default is true)
	EnableK8s = "enable-k8s"

	// AgentHealthRequireK8sConnectivity determines whether the agent health endpoint requires k8s connectivity
	AgentHealthRequireK8sConnectivity = "agent-health-require-k8s-connectivity"

	// K8sAPIServer is the kubernetes api address server (for https use --k8s-kubeconfig-path instead)
	K8sAPIServer = "k8s-api-server"

	// K8sAPIServerURLs is the kubernetes api address server url
	K8sAPIServerURLs = "k8s-api-server-urls"

	// K8sKubeConfigPath is the absolute path of the kubernetes kubeconfig file
	K8sKubeConfigPath = "k8s-kubeconfig-path"

	// K8sSyncTimeout is the timeout since last event was received to synchronize all resources with k8s.
	K8sSyncTimeoutName = "k8s-sync-timeout"

	// AllocatorListTimeout is the timeout to list initial allocator state.
	AllocatorListTimeoutName = "allocator-list-timeout"

	// KeepConfig when restoring state, keeps containers' configuration in place
	KeepConfig = "keep-config"

	// KVStore key-value store type
	KVStore = "kvstore"

	// KVStoreOpt key-value store options
	KVStoreOpt = "kvstore-opt"

	// Labels is the list of label prefixes used to determine identity of an endpoint
	Labels = "labels"

	// LabelPrefixFile is the valid label prefixes file path
	LabelPrefixFile = "label-prefix-file"

	// EnableHostFirewall enables network policies for the host
	EnableHostFirewall = "enable-host-firewall"

	// EnableHostLegacyRouting enables the old routing path via stack.
	EnableHostLegacyRouting = "enable-host-legacy-routing"

	// NodePortAcceleration indicates whether NodePort should be accelerated
	// via XDP ("none", "generic", "native", or "best-effort")
	NodePortAcceleration = "node-port-acceleration"

	// Alias to DSR/IPIP IPv4 source CIDR
	LoadBalancerRSSv4CIDR = "bpf-lb-rss-ipv4-src-cidr"

	// Alias to DSR/IPIP IPv6 source CIDR
	LoadBalancerRSSv6CIDR = "bpf-lb-rss-ipv6-src-cidr"

	// LoadBalancerNat46X64 enables NAT46 and NAT64 for services
	LoadBalancerNat46X64 = "bpf-lb-nat46x64"

	// Alias to NodePortAcceleration
	LoadBalancerAcceleration = "bpf-lb-acceleration"

	// LoadBalancerIPIPSockMark enables sock-lb logic to force service traffic via IPIP
	LoadBalancerIPIPSockMark = "bpf-lb-ipip-sock-mark"

	// LoadBalancerExternalControlPlane switch skips connectivity to kube-apiserver
	// which is relevant in lb-only mode
	LoadBalancerExternalControlPlane = "bpf-lb-external-control-plane"

	// NodePortBindProtection rejects bind requests to NodePort service ports
	NodePortBindProtection = "node-port-bind-protection"

	// EnableAutoProtectNodePortRange enables appending NodePort range to
	// net.ipv4.ip_local_reserved_ports if it overlaps with ephemeral port
	// range (net.ipv4.ip_local_port_range)
	EnableAutoProtectNodePortRange = "enable-auto-protect-node-port-range"

	// KubeProxyReplacement controls how to enable kube-proxy replacement
	// features in BPF datapath
	KubeProxyReplacement = "kube-proxy-replacement"

	// EnableIdentityMark enables setting the mark field with the identity for
	// local traffic. This may be disabled if chaining modes and Cilium use
	// conflicting marks.
	EnableIdentityMark = "enable-identity-mark"

	// AddressScopeMax controls the maximum address scope for addresses to be
	// considered local ones with HOST_ID in the ipcache
	AddressScopeMax = "local-max-addr-scope"

	// EnableLocalRedirectPolicy enables support for local redirect policy
	EnableLocalRedirectPolicy = "enable-local-redirect-policy"

	// EnableMKE enables MKE specific 'chaining' for kube-proxy replacement
	EnableMKE = "enable-mke"

	// CgroupPathMKE points to the cgroupv1 net_cls mount instance
	CgroupPathMKE = "mke-cgroup-mount"

	// LibDir enables the directory path to store runtime build environment
	LibDir = "lib-dir"

	// LogDriver sets logging endpoints to use for example syslog, fluentd
	LogDriver = "log-driver"

	// LogOpt sets log driver options for cilium
	LogOpt = "log-opt"

	// EnableRemoteNodeMasquerade Masquerade packets from endpoints leaving the host destined to a remote node in BPF masquerading mode. This option requires to set enable-bpf-masquerade to true.
	EnableRemoteNodeMasquerade = "enable-remote-node-masquerade"

	// EnableIPv4Masquerade masquerades IPv4 packets from endpoints leaving the host.
	EnableIPv4Masquerade = "enable-ipv4-masquerade"

	// EnableIPv6Masquerade masquerades IPv6 packets from endpoints leaving the host.
	EnableIPv6Masquerade = "enable-ipv6-masquerade"

	// EnableBPFClockProbe selects a more efficient source clock (jiffies vs ktime)
	EnableBPFClockProbe = "enable-bpf-clock-probe"

	// EnableBPFMasquerade masquerades packets from endpoints leaving the host with BPF instead of iptables
	EnableBPFMasquerade = "enable-bpf-masquerade"

	// EnableMasqueradeRouteSource masquerades to the source route IP address instead of the interface one
	EnableMasqueradeRouteSource = "enable-masquerade-to-route-source"

	// EnableIPMasqAgent enables BPF ip-masq-agent
	EnableIPMasqAgent = "enable-ip-masq-agent"

	// EnableIPv4EgressGateway enables the IPv4 egress gateway
	EnableIPv4EgressGateway = "enable-ipv4-egress-gateway"

	// EnableEgressGateway enables the egress gateway
	EnableEgressGateway = "enable-egress-gateway"

	// EnableEnvoyConfig enables processing of CiliumClusterwideEnvoyConfig and CiliumEnvoyConfig CRDs
	EnableEnvoyConfig = "enable-envoy-config"

	// IPMasqAgentConfigPath is the configuration file path
	IPMasqAgentConfigPath = "ip-masq-agent-config-path"

	// InstallIptRules sets whether Cilium should install any iptables in general
	InstallIptRules = "install-iptables-rules"

	// InstallNoConntrackIptRules instructs Cilium to install Iptables rules
	// to skip netfilter connection tracking on all pod traffic.
	InstallNoConntrackIptRules = "install-no-conntrack-iptables-rules"

	// ContainerIPLocalReservedPorts instructs the Cilium CNI plugin to reserve
	// the provided comma-separated list of ports in the container network namespace
	ContainerIPLocalReservedPorts = "container-ip-local-reserved-ports"

	// IPv6NodeAddr is the IPv6 address of node
	IPv6NodeAddr = "ipv6-node"

	// IPv4NodeAddr is the IPv4 address of node
	IPv4NodeAddr = "ipv4-node"

	// Restore restores state, if possible, from previous daemon
	Restore = "restore"

	// SocketPath sets daemon's socket path to listen for connections
	SocketPath = "socket-path"

	// StateDir is the directory path to store runtime state
	StateDir = "state-dir"

	// TracePayloadlen length of payload to capture when tracing native packets.
	TracePayloadlen = "trace-payloadlen"

	// TracePayloadlenOverlay length of payload to capture when tracing overlay packets.
	TracePayloadlenOverlay = "trace-payloadlen-overlay"

	// Version prints the version information
	Version = "version"

	// EnableXDPPrefilter enables XDP-based prefiltering
	EnableXDPPrefilter = "enable-xdp-prefilter"

	// EnableTCX enables attaching endpoint programs using tcx if the kernel supports it
	EnableTCX = "enable-tcx"

	ProcFs = "procfs"

	// PrometheusServeAddr IP:Port on which to serve prometheus metrics (pass ":Port" to bind on all interfaces, "" is off)
	PrometheusServeAddr = "prometheus-serve-addr"

	// ExternalEnvoyProxy defines whether the Envoy is deployed externally in form of a DaemonSet or not.
	ExternalEnvoyProxy = "external-envoy-proxy"

	// CMDRef is the path to cmdref output directory
	CMDRef = "cmdref"

	// DNSPolicyUnloadOnShutdown is the name of the dns-policy-unload-on-shutdown option.
	DNSPolicyUnloadOnShutdown = "dns-policy-unload-on-shutdown"

	// ToFQDNsMinTTL is the minimum time, in seconds, to use DNS data for toFQDNs policies.
	ToFQDNsMinTTL = "tofqdns-min-ttl"

	// ToFQDNsProxyPort is the global port on which the in-agent DNS proxy should listen. Default 0 is a OS-assigned port.
	ToFQDNsProxyPort = "tofqdns-proxy-port"

	// ToFQDNsMaxIPsPerHost defines the maximum number of IPs to maintain
	// for each FQDN name in an endpoint's FQDN cache
	ToFQDNsMaxIPsPerHost = "tofqdns-endpoint-max-ip-per-hostname"

	// ToFQDNsMaxDeferredConnectionDeletes defines the maximum number of IPs to
	// retain for expired DNS lookups with still-active connections"
	ToFQDNsMaxDeferredConnectionDeletes = "tofqdns-max-deferred-connection-deletes"

	// ToFQDNsIdleConnectionGracePeriod defines the connection idle time during which
	// previously active connections with expired DNS lookups are still considered alive
	ToFQDNsIdleConnectionGracePeriod = "tofqdns-idle-connection-grace-period"

	// ToFQDNsPreCache is a path to a file with DNS cache data to insert into the
	// global cache on startup.
	// The file is not re-read after agent start.
	ToFQDNsPreCache = "tofqdns-pre-cache"

	// DNSProxyConcurrencyLimit limits parallel processing of DNS messages in
	// DNS proxy at any given point in time.
	DNSProxyConcurrencyLimit = "dnsproxy-concurrency-limit"

	// DNSProxyLockCount is the array size containing mutexes which protect
	// against parallel handling of DNS response IPs.
	DNSProxyLockCount = "dnsproxy-lock-count"

	// DNSProxyLockTimeout is timeout when acquiring the locks controlled by
	// DNSProxyLockCount.
	DNSProxyLockTimeout = "dnsproxy-lock-timeout"

	// DNSProxySocketLingerTimeout defines how many seconds we wait for the connection
	// between the DNS proxy and the upstream server to be closed.
	DNSProxySocketLingerTimeout = "dnsproxy-socket-linger-timeout"

	// DNSProxyEnableTransparentMode enables transparent mode for the DNS proxy.
	DNSProxyEnableTransparentMode = "dnsproxy-enable-transparent-mode"

	// DNSProxyInsecureSkipTransparentModeCheck is a hidden flag that allows users
	// to disable transparent mode even if IPSec is enabled
	DNSProxyInsecureSkipTransparentModeCheck = "dnsproxy-insecure-skip-transparent-mode-check"

	// MTUName is the name of the MTU option
	MTUName = "mtu"

	// RouteMetric is the name of the route-metric option
	RouteMetric = "route-metric"

	// DatapathMode is the name of the DatapathMode option
	DatapathMode = "datapath-mode"

	// EnableSocketLB is the name for the option to enable the socket LB
	EnableSocketLB = "bpf-lb-sock"

	// EnableSocketLBTracing is the name for the option to enable the socket LB tracing
	EnableSocketLBTracing = "trace-sock"

	// BPFSocketLBHostnsOnly is the name of the BPFSocketLBHostnsOnly option
	BPFSocketLBHostnsOnly = "bpf-lb-sock-hostns-only"

	// EnableSocketLBPodConnectionTermination enables termination of pod connections
	// to deleted service backends when socket-LB is enabled.
	EnableSocketLBPodConnectionTermination = "bpf-lb-sock-terminate-pod-connections"

	// RoutingMode is the name of the option to choose between native routing and tunneling mode
	RoutingMode = "routing-mode"

	// ServiceNoBackendResponse is the name of the option to pick how to handle traffic for services
	// without any backends
	ServiceNoBackendResponse = "service-no-backend-response"

	// ServiceNoBackendResponseReject is the name of the option to reject traffic for services
	// without any backends
	ServiceNoBackendResponseReject = "reject"

	// ServiceNoBackendResponseDrop is the name of the option to drop traffic for services
	// without any backends
	ServiceNoBackendResponseDrop = "drop"

	// PolicyDenyResponse is the name of the option to pick how to handle ipv4 egress traffic denied by policy
	PolicyDenyResponse = "policy-deny-response"

	// PolicyDenyResponseIcmp is the name of the option to reject traffic denied by policy with an ICMP response
	PolicyDenyResponseIcmp = "icmp"

	// PolicyDenyResponseNone is the name of the option to silently drop traffic denied by policy
	PolicyDenyResponseNone = "none"

	// MaxInternalTimerDelay sets a maximum on all periodic timers in
	// the agent in order to flush out timer-related bugs in the agent.
	MaxInternalTimerDelay = "max-internal-timer-delay"

	// MonitorAggregationName specifies the MonitorAggregationLevel on the
	// comandline.
	MonitorAggregationName = "monitor-aggregation"

	// MonitorAggregationInterval configures interval for monitor-aggregation
	MonitorAggregationInterval = "monitor-aggregation-interval"

	// MonitorAggregationFlags configures TCP flags used by monitor aggregation.
	MonitorAggregationFlags = "monitor-aggregation-flags"

	// ciliumEnvPrefix is the prefix used for environment variables
	ciliumEnvPrefix = "CILIUM_"

	// CNIChainingMode configures which CNI plugin Cilium is chained with.
	CNIChainingMode = "cni-chaining-mode"

	// CNIChainingTarget is the name of a CNI network in to which we should
	// insert our plugin configuration
	CNIChainingTarget = "cni-chaining-target"

	// AuthMapEntriesMin defines the minimum auth map limit.
	AuthMapEntriesMin = 1 << 8

	// AuthMapEntriesMax defines the maximum auth map limit.
	AuthMapEntriesMax = 1 << 24

	// AuthMapEntriesDefault defines the default auth map limit.
	AuthMapEntriesDefault = 1 << 19

	// BPFConntrackAccounting controls whether CT accounting for packets and bytes is enabled
	BPFConntrackAccountingDefault = false

	// AuthMapEntriesName configures max entries for BPF auth map.
	AuthMapEntriesName = "bpf-auth-map-max"

	// CTMapEntriesGlobalTCPDefault is the default maximum number of entries
	// in the TCP CT table.
	CTMapEntriesGlobalTCPDefault = 2 << 18 // 512Ki

	// CTMapEntriesGlobalAnyDefault is the default maximum number of entries
	// in the non-TCP CT table.
	CTMapEntriesGlobalAnyDefault = 2 << 17 // 256Ki

	// CTMapEntriesGlobalTCPName configures max entries for the TCP CT
	// table.
	CTMapEntriesGlobalTCPName = "bpf-ct-global-tcp-max"

	// CTMapEntriesGlobalAnyName configures max entries for the non-TCP CT
	// table.
	CTMapEntriesGlobalAnyName = "bpf-ct-global-any-max"

	// CTMapEntriesTimeout* name option and default value mappings
	CTMapEntriesTimeoutSYNName         = "bpf-ct-timeout-regular-tcp-syn"
	CTMapEntriesTimeoutFINName         = "bpf-ct-timeout-regular-tcp-fin"
	CTMapEntriesTimeoutTCPName         = "bpf-ct-timeout-regular-tcp"
	CTMapEntriesTimeoutAnyName         = "bpf-ct-timeout-regular-any"
	CTMapEntriesTimeoutSVCTCPName      = "bpf-ct-timeout-service-tcp"
	CTMapEntriesTimeoutSVCTCPGraceName = "bpf-ct-timeout-service-tcp-grace"
	CTMapEntriesTimeoutSVCAnyName      = "bpf-ct-timeout-service-any"

	// NATMapEntriesGlobalDefault holds the default size of the NAT map
	// and is 2/3 of the full CT size as a heuristic
	NATMapEntriesGlobalDefault = int((CTMapEntriesGlobalTCPDefault + CTMapEntriesGlobalAnyDefault) * 2 / 3)

	// SockRevNATMapEntriesDefault holds the default size of the SockRev NAT map
	// and is the same size of CTMapEntriesGlobalAnyDefault as a heuristic given
	// that sock rev NAT is mostly used for UDP and getpeername only.
	SockRevNATMapEntriesDefault = CTMapEntriesGlobalAnyDefault

	// MapEntriesGlobalDynamicSizeRatioName is the name of the option to
	// set the ratio of total system memory to use for dynamic sizing of the
	// CT, NAT, Neighbor and SockRevNAT BPF maps.
	MapEntriesGlobalDynamicSizeRatioName = "bpf-map-dynamic-size-ratio"

	// LimitTableAutoGlobalTCPMin defines the minimum TCP CT table limit for
	// dynamic size ration calculation.
	LimitTableAutoGlobalTCPMin = 1 << 17 // 128Ki entries

	// LimitTableAutoGlobalAnyMin defines the minimum UDP CT table limit for
	// dynamic size ration calculation.
	LimitTableAutoGlobalAnyMin = 1 << 16 // 64Ki entries

	// LimitTableAutoNatGlobalMin defines the minimum NAT limit for dynamic size
	// ration calculation.
	LimitTableAutoNatGlobalMin = 1 << 17 // 128Ki entries

	// LimitTableAutoSockRevNatMin defines the minimum SockRevNAT limit for
	// dynamic size ration calculation.
	LimitTableAutoSockRevNatMin = 1 << 16 // 64Ki entries

	// LimitTableMin defines the minimum CT or NAT table limit
	LimitTableMin = 1 << 10 // 1Ki entries

	// LimitTableMax defines the maximum CT or NAT table limit
	LimitTableMax = 1 << 24 // 16Mi entries (~1GiB of entries per map)

	// PolicyMapMin defines the minimum policy map limit.
	PolicyMapMin = 1 << 8

	// PolicyMapMax defines the maximum policy map limit.
	PolicyMapMax = 1 << 16

	// FragmentsMapMin defines the minimum fragments map limit.
	FragmentsMapMin = 1 << 8

	// FragmentsMapMax defines the maximum fragments map limit.
	FragmentsMapMax = 1 << 16

	// NATMapEntriesGlobalName configures max entries for BPF NAT table
	NATMapEntriesGlobalName = "bpf-nat-global-max"

	// NeighMapEntriesGlobalName configures max entries for BPF neighbor table
	NeighMapEntriesGlobalName = "bpf-neigh-global-max"

	// PolicyMapFullReconciliationInterval sets the interval for performing the full
	// reconciliation of the endpoint policy map.
	PolicyMapFullReconciliationIntervalName = "bpf-policy-map-full-reconciliation-interval"

	// EgressGatewayPolicyMapEntriesName configures max entries for egress gateway's policy
	// map.
	EgressGatewayPolicyMapEntriesName = "egress-gateway-policy-map-max"

	// LogSystemLoadConfigName is the name of the option to enable system
	// load logging
	LogSystemLoadConfigName = "log-system-load"

	// DisableCiliumEndpointCRDName is the name of the option to disable
	// use of the CEP CRD
	DisableCiliumEndpointCRDName = "disable-endpoint-crd"

	// MaxCtrlIntervalName and MaxCtrlIntervalNameEnv allow configuration
	// of MaxControllerInterval.
	MaxCtrlIntervalName = "max-controller-interval"

	// K8sNamespaceName is the name of the K8sNamespace option
	K8sNamespaceName = "k8s-namespace"

	// AgentNotReadyNodeTaintKeyName is the name of the option to set
	// AgentNotReadyNodeTaintKey
	AgentNotReadyNodeTaintKeyName = "agent-not-ready-taint-key"

	// EnableIPv4Name is the name of the option to enable IPv4 support
	EnableIPv4Name = "enable-ipv4"

	// EnableIPv6Name is the name of the option to enable IPv6 support
	EnableIPv6Name = "enable-ipv6"

	// EnableIPv6NDPName is the name of the option to enable IPv6 NDP support
	EnableIPv6NDPName = "enable-ipv6-ndp"

	// EnableSRv6 is the name of the option to enable SRv6 encapsulation support
	EnableSRv6 = "enable-srv6"

	// SRv6EncapModeName is the name of the option to specify the SRv6 encapsulation mode
	SRv6EncapModeName = "srv6-encap-mode"

	// EnableSCTPName is the name of the option to enable SCTP support
	EnableSCTPName = "enable-sctp"

	// EnableNat46X64Gateway enables L3 based NAT46 and NAT64 gateway
	EnableNat46X64Gateway = "enable-nat46x64-gateway"

	// IPv6MCastDevice is the name of the option to select IPv6 multicast device
	IPv6MCastDevice = "ipv6-mcast-device"

	// BPFEventsDefaultRateLimit specifies limit of messages per second that can be written to
	// BPF events map. This limit is defined for all types of events except dbg.
	// The number of messages is averaged, meaning that if no messages were written
	// to the map over 5 seconds, it's possible to write more events than the value of rate limit
	// in the 6th second.
	//
	// If BPFEventsDefaultRateLimit > 0, non-zero value for BPFEventsDefaultBurstLimit must also be provided
	// lest the configuration is considered invalid.
	// If both rate and burst limit are 0 or not specified, no limit is imposed.
	BPFEventsDefaultRateLimit = "bpf-events-default-rate-limit"

	// BPFEventsDefaultBurstLimit specifies the maximum number of messages that can be written
	// to BPF events map in 1 second. This limit is defined for all types of events except dbg.
	//
	// If BPFEventsDefaultBurstLimit > 0, non-zero value for BPFEventsDefaultRateLimit must also be provided
	// lest the configuration is considered invalid.
	// If both burst and rate limit are 0 or not specified, no limit is imposed.
	BPFEventsDefaultBurstLimit = "bpf-events-default-burst-limit"

	// FQDNRejectResponseCode is the name for the option for dns-proxy reject response code
	FQDNRejectResponseCode = "tofqdns-dns-reject-response-code"

	// FQDNProxyDenyWithNameError is useful when stub resolvers, like the one
	// in Alpine Linux's libc (musl), treat a REFUSED as a resolution error.
	// This happens when trying a DNS search list, as in kubernetes, and breaks
	// even whitelisted DNS names.
	FQDNProxyDenyWithNameError = "nameError"

	// FQDNProxyDenyWithRefused is the response code for Domain refused. It is
	// the default for denied DNS requests.
	FQDNProxyDenyWithRefused = "refused"

	// FQDNProxyResponseMaxDelay is the maximum time the proxy holds back a response
	FQDNProxyResponseMaxDelay = "tofqdns-proxy-response-max-delay"

	// FQDNRegexCompileLRUSize is the size of the FQDN regex compilation LRU.
	// Useful for heavy but repeated FQDN MatchName or MatchPattern use.
	FQDNRegexCompileLRUSize = "fqdn-regex-compile-lru-size"

	// PreAllocateMapsName is the name of the option PreAllocateMaps
	PreAllocateMapsName = "preallocate-bpf-maps"

	// EnableBPFTProxy option supports enabling or disabling BPF TProxy.
	EnableBPFTProxy = "enable-bpf-tproxy"

	// EnableAutoDirectRoutingName is the name for the EnableAutoDirectRouting option
	EnableAutoDirectRoutingName = "auto-direct-node-routes"

	// DirectRoutingSkipUnreachableName is the name for the DirectRoutingSkipUnreachable option
	DirectRoutingSkipUnreachableName = "direct-routing-skip-unreachable"

	// BootIDFilename is a hidden flag that allows users to specify a
	// filename other than /proc/sys/kernel/random/boot_id. This can be
	// useful for testing purposes in local containerized cluster.
	BootIDFilename = "boot-id-file"

	// EnableL2Announcements is the name of the option to enable l2 announcements
	EnableL2Announcements = "enable-l2-announcements"

	// L2AnnouncerLeaseDuration, if a lease has not been renewed for X amount of time, a new leader can be chosen.
	L2AnnouncerLeaseDuration = "l2-announcements-lease-duration"

	// L2AnnouncerRenewDeadline, the leader will renew the lease every X amount of time.
	L2AnnouncerRenewDeadline = "l2-announcements-renew-deadline"

	// L2AnnouncerRetryPeriod, on renew failure, retry after X amount of time.
	L2AnnouncerRetryPeriod = "l2-announcements-retry-period"

	// EnableEncryptionStrictMode is the name of the option to enable strict encryption mode.
	EnableEncryptionStrictMode = "enable-encryption-strict-mode"

	// EncryptionStrictModeCIDR is the CIDR in which the strict encryption mode should be enforced.
	EncryptionStrictModeCIDR = "encryption-strict-mode-cidr"

	// EncryptionStrictModeAllowRemoteNodeIdentities allows dynamic lookup of remote node identities.
	// This is required when tunneling is used
	// or direct routing is used and the node CIDR and pod CIDR overlap.
	EncryptionStrictModeAllowRemoteNodeIdentities = "encryption-strict-mode-allow-remote-node-identities"

	// KVstoreLeaseTTL is the time-to-live for lease in kvstore.
	KVstoreLeaseTTL = "kvstore-lease-ttl"

	// KVstoreMaxConsecutiveQuorumErrorsName is the maximum number of acceptable
	// kvstore consecutive quorum errors before the agent assumes permanent failure
	KVstoreMaxConsecutiveQuorumErrorsName = "kvstore-max-consecutive-quorum-errors"

	// IdentityChangeGracePeriod is the name of the
	// IdentityChangeGracePeriod option
	IdentityChangeGracePeriod = "identity-change-grace-period"

	// CiliumIdentityMaxJitter is the maximum duration to delay processing a CiliumIdentity under certain conditions (default: 30s).
	CiliumIdentityMaxJitter = "identity-max-jitter"

	// IdentityRestoreGracePeriod is the name of the
	// IdentityRestoreGracePeriod option
	IdentityRestoreGracePeriod = "identity-restore-grace-period"

	// EnableHealthChecking is the name of the EnableHealthChecking option
	EnableHealthChecking = "enable-health-checking"

	// EnableEndpointHealthChecking is the name of the EnableEndpointHealthChecking option
	EnableEndpointHealthChecking = "enable-endpoint-health-checking"

	// EnableHealthCheckLoadBalancerIP is the name of the EnableHealthCheckLoadBalancerIP option
	EnableHealthCheckLoadBalancerIP = "enable-health-check-loadbalancer-ip"

	// HealthCheckICMPFailureThreshold is the name of the HealthCheckICMPFailureThreshold option
	HealthCheckICMPFailureThreshold = "health-check-icmp-failure-threshold"

	// EndpointQueueSize is the size of the EventQueue per-endpoint.
	EndpointQueueSize = "endpoint-queue-size"

	// EndpointGCInterval interval to attempt garbage collection of
	// endpoints that are no longer alive and healthy.
	EndpointGCInterval = "endpoint-gc-interval"

	// EndpointRegenInterval is the interval of the periodic endpoint regeneration loop.
	EndpointRegenInterval = "endpoint-regen-interval"

	// ServiceLoopbackIPv4 is the address to use for service loopback SNAT
	ServiceLoopbackIPv4 = "ipv4-service-loopback-address"

	// ServiceLoopbackIPv6 is the address to use for service loopback SNAT
	ServiceLoopbackIPv6 = "ipv6-service-loopback-address"

	// LocalRouterIPv4 is the link-local IPv4 address to use for Cilium router device
	LocalRouterIPv4 = "local-router-ipv4"

	// LocalRouterIPv6 is the link-local IPv6 address to use for Cilium router device
	LocalRouterIPv6 = "local-router-ipv6"

	// EnableEndpointRoutes enables use of per endpoint routes
	EnableEndpointRoutes = "enable-endpoint-routes"

	// ExcludeLocalAddress excludes certain addresses to be recognized as a
	// local address
	ExcludeLocalAddress = "exclude-local-address"

	// IPv4PodSubnets A list of IPv4 subnets that pods may be
	// assigned from. Used with CNI chaining where IPs are not directly managed
	// by Cilium.
	IPv4PodSubnets = "ipv4-pod-subnets"

	// IPv6PodSubnets A list of IPv6 subnets that pods may be
	// assigned from. Used with CNI chaining where IPs are not directly managed
	// by Cilium.
	IPv6PodSubnets = "ipv6-pod-subnets"

	// IPAM is the IPAM method to use
	IPAM = "ipam"

	// IPAMMultiPoolPreAllocation defines the pre-allocation value for each IPAM pool
	IPAMMultiPoolPreAllocation = "ipam-multi-pool-pre-allocation"

	// IPAMDefaultIPPool defines the default IP Pool when using multi-pool
	IPAMDefaultIPPool = "ipam-default-ip-pool"

	// XDPModeNative for loading progs with XDPModeLinkDriver
	XDPModeNative = "native"

	// XDPModeBestEffort for loading progs with XDPModeLinkDriver
	XDPModeBestEffort = "best-effort"

	// XDPModeGeneric for loading progs with XDPModeLinkGeneric
	XDPModeGeneric = "testing-only"

	// XDPModeDisabled for not having XDP enabled
	XDPModeDisabled = "disabled"

	// XDPModeLinkDriver is the tc selector for native XDP
	XDPModeLinkDriver = "xdpdrv"

	// XDPModeLinkGeneric is the tc selector for generic XDP
	XDPModeLinkGeneric = "xdpgeneric"

	// XDPModeLinkNone for not having XDP enabled
	XDPModeLinkNone = XDPModeDisabled

	// K8sClientQPSLimit is the queries per second limit for the K8s client. Defaults to k8s client defaults.
	K8sClientQPSLimit = "k8s-client-qps"

	// K8sClientBurst is the burst value allowed for the K8s client. Defaults to k8s client defaults.
	K8sClientBurst = "k8s-client-burst"

	// AutoCreateCiliumNodeResource enables automatic creation of a
	// CiliumNode resource for the local node
	AutoCreateCiliumNodeResource = "auto-create-cilium-node-resource"

	// ExcludeNodeLabelPatterns allows for excluding unnecessary labels from being propagated from k8s node to cilium
	// node object. This allows for avoiding unnecessary events being broadcast to all nodes in the cluster.
	ExcludeNodeLabelPatterns = "exclude-node-label-patterns"

	// IPv4NativeRoutingCIDR describes a v4 CIDR in which pod IPs are routable
	IPv4NativeRoutingCIDR = "ipv4-native-routing-cidr"

	// IPv6NativeRoutingCIDR describes a v6 CIDR in which pod IPs are routable
	IPv6NativeRoutingCIDR = "ipv6-native-routing-cidr"

	// MasqueradeInterfaces is the selector used to select interfaces subject to
	// egress masquerading
	MasqueradeInterfaces = "egress-masquerade-interfaces"

	// PolicyTriggerInterval is the amount of time between triggers of policy
	// updates are invoked.
	PolicyTriggerInterval = "policy-trigger-interval"

	// IdentityAllocationMode specifies what mode to use for identity
	// allocation
	IdentityAllocationMode = "identity-allocation-mode"

	// IdentityAllocationModeKVstore enables use of a key-value store such
	// as etcd for identity allocation
	IdentityAllocationModeKVstore = "kvstore"

	// IdentityAllocationModeCRD enables use of Kubernetes CRDs for
	// identity allocation
	IdentityAllocationModeCRD = "crd"

	// IdentityAllocationModeDoubleWriteReadKVstore writes identities to the KVStore and as CRDs at the same time.
	// Identities are then read from the KVStore.
	IdentityAllocationModeDoubleWriteReadKVstore = "doublewrite-readkvstore"

	// IdentityAllocationModeDoubleWriteReadCRD writes identities to the KVStore and as CRDs at the same time.
	// Identities are then read from the CRDs.
	IdentityAllocationModeDoubleWriteReadCRD = "doublewrite-readcrd"

	// EnableLocalNodeRoute controls installation of the route which points
	// the allocation prefix of the local node.
	EnableLocalNodeRoute = "enable-local-node-route"

	// PolicyAuditModeArg argument enables policy audit mode.
	PolicyAuditModeArg = "policy-audit-mode"

	// PolicyAccountingArg argument enable policy accounting.
	PolicyAccountingArg = "policy-accounting"

	// K8sClientConnectionTimeout configures the timeout for K8s client connections.
	K8sClientConnectionTimeout = "k8s-client-connection-timeout"

	// K8sClientConnectionKeepAlive configures the keep alive duration for K8s client connections.
	K8sClientConnectionKeepAlive = "k8s-client-connection-keep-alive"

	// K8sHeartbeatTimeout configures the timeout for apiserver heartbeat
	K8sHeartbeatTimeout = "k8s-heartbeat-timeout"

	// EnableIPv4FragmentsTrackingName is the name of the option to enable
	// IPv4 fragments tracking for L4-based lookups. Needs LRU map support.
	EnableIPv4FragmentsTrackingName = "enable-ipv4-fragment-tracking"

	// EnableIPv6FragmentsTrackingName is the name of the option to enable
	// IPv6 fragments tracking for L4-based lookups. Needs LRU map support.
	EnableIPv6FragmentsTrackingName = "enable-ipv6-fragment-tracking"

	// FragmentsMapEntriesName configures max entries for BPF fragments
	// tracking map.
	FragmentsMapEntriesName = "bpf-fragments-map-max"

	// K8sEnableAPIDiscovery enables Kubernetes API discovery
	K8sEnableAPIDiscovery = "enable-k8s-api-discovery"

	// EgressMultiHomeIPRuleCompat instructs Cilium to use a new scheme to
	// store rules and routes under ENI and Azure IPAM modes, if false.
	// Otherwise, it will use the old scheme.
	EgressMultiHomeIPRuleCompat = "egress-multi-home-ip-rule-compat"

	// Install ingress/egress routes through uplink on host for Pods when working with
	// delegated IPAM plugin.
	InstallUplinkRoutesForDelegatedIPAM = "install-uplink-routes-for-delegated-ipam"

	// BGPSecretsNamespace is the Kubernetes namespace to get BGP control plane secrets from.
	BGPSecretsNamespace = "bgp-secrets-namespace"

	// VLANBPFBypass instructs Cilium to bypass bpf logic for vlan tagged packets
	VLANBPFBypass = "vlan-bpf-bypass"

	// DisableExternalIPMitigation disable ExternalIP mitigation (CVE-2020-8554)
	DisableExternalIPMitigation = "disable-external-ip-mitigation"

	// EnableICMPRules enables ICMP-based rule support for Cilium Network Policies.
	EnableICMPRules = "enable-icmp-rules"

	// BypassIPAvailabilityUponRestore bypasses the IP availability error
	// within IPAM upon endpoint restore and allows the use of the restored IP
	// regardless of whether it's available in the pool.
	BypassIPAvailabilityUponRestore = "bypass-ip-availability-upon-restore"

	// EnableVTEP enables cilium VXLAN VTEP integration
	EnableVTEP = "enable-vtep"

	// VTEP CIDR Mask applies to all VtepCIDR
	VtepMask = "vtep-mask"

	// TCFilterPriority sets the priority of the cilium tc filter, enabling other
	// filters to be inserted prior to the cilium filter.
	TCFilterPriority = "bpf-filter-priority"

	// Flag to enable BGP control plane features
	EnableBGPControlPlane = "enable-bgp-control-plane"

	// EnableBGPControlPlaneStatusReport enables BGP Control Plane CRD status reporting
	EnableBGPControlPlaneStatusReport = "enable-bgp-control-plane-status-report"

	// BGP router-id allocation mode
	BGPRouterIDAllocationMode = "bgp-router-id-allocation-mode"

	// BGP router-id allocation IP pool
	BGPRouterIDAllocationIPPool = "bgp-router-id-allocation-ip-pool"

	// EnablePMTUDiscovery enables path MTU discovery to send ICMP
	// fragmentation-needed replies to the client (when needed).
	EnablePMTUDiscovery = "enable-pmtu-discovery"

	// BPFMapEventBuffers specifies what maps should have event buffers enabled,
	// and the max size and TTL of events in the buffers should be.
	BPFMapEventBuffers = "bpf-map-event-buffers"

	// IPAMCiliumNodeUpdateRate is the maximum rate at which the CiliumNode custom
	// resource is updated.
	IPAMCiliumNodeUpdateRate = "ipam-cilium-node-update-rate"

	// EnableK8sNetworkPolicy enables support for K8s NetworkPolicy.
	EnableK8sNetworkPolicy = "enable-k8s-networkpolicy"

	// EnableCiliumNetworkPolicy enables support for Cilium Network Policy.
	EnableCiliumNetworkPolicy = "enable-cilium-network-policy"

	// EnableCiliumClusterwideNetworkPolicy enables support for Cilium Clusterwide
	// Network Policy.
	EnableCiliumClusterwideNetworkPolicy = "enable-cilium-clusterwide-network-policy"

	// PolicyCIDRMatchMode defines the entities that CIDR selectors can reach
	PolicyCIDRMatchMode = "policy-cidr-match-mode"

	// EnableNodeSelectorLabels enables use of the node label based identity
	EnableNodeSelectorLabels = "enable-node-selector-labels"

	// NodeLabels is the list of label prefixes used to determine identity of a node (requires enabling of
	// EnableNodeSelectorLabels)
	NodeLabels = "node-labels"

	// BPFEventsDropEnabled defines the DropNotification setting for any endpoint
	BPFEventsDropEnabled = "bpf-events-drop-enabled"

	// BPFEventsPolicyVerdictEnabled defines the PolicyVerdictNotification setting for any endpoint
	BPFEventsPolicyVerdictEnabled = "bpf-events-policy-verdict-enabled"

	// BPFEventsTraceEnabled defines the TraceNotification setting for any endpoint
	BPFEventsTraceEnabled = "bpf-events-trace-enabled"

	// BPFConntrackAccounting controls whether CT accounting for packets and bytes is enabled
	BPFConntrackAccounting = "bpf-conntrack-accounting"

	// EnableNonDefaultDenyPolicies allows policies to define whether they are operating in default-deny mode
	EnableNonDefaultDenyPolicies = "enable-non-default-deny-policies"

	// EnableEndpointLockdownOnPolicyOverflow enables endpoint lockdown when an endpoint's
	// policy map overflows.
	EnableEndpointLockdownOnPolicyOverflow = "enable-endpoint-lockdown-on-policy-overflow"

	// ConnectivityProbeFrequencyRatio is the name of the option to specify the connectivity probe frequency
	ConnectivityProbeFrequencyRatio = "connectivity-probe-frequency-ratio"

	// EnableExtendedIPProtocols controls whether traffic with extended IP protocols is supported in datapath.
	EnableExtendedIPProtocols = "enable-extended-ip-protocols"

	// IPTracingOptionType specifies what IPv4 option type should be used to extract trace information from a packet
	IPTracingOptionType = "ip-tracing-option-type"
)

// Default string arguments
var (
	FQDNRejectOptions = []string{FQDNProxyDenyWithNameError, FQDNProxyDenyWithRefused}

	// MonitorAggregationFlagsDefault ensure that all TCP flags trigger
	// monitor notifications even under medium monitor aggregation.
	MonitorAggregationFlagsDefault = []string{"syn", "fin", "rst"}
)

// Available options for DaemonConfig.RoutingMode
const (
	// RoutingModeNative specifies native routing mode
	RoutingModeNative = "native"

	// RoutingModeTunnel specifies tunneling mode
	RoutingModeTunnel = "tunnel"
)

const (
	// HTTP403Message specifies the response body for 403 responses, defaults to "Access denied"
	HTTP403Message = "http-403-msg"

	// ReadCNIConfiguration reads the CNI configuration file and extracts
	// Cilium relevant information. This can be used to pass per node
	// configuration to Cilium.
	ReadCNIConfiguration = "read-cni-conf"

	// WriteCNIConfigurationWhenReady writes the CNI configuration to the
	// specified location once the agent is ready to serve requests. This
	// allows to keep a Kubernetes node NotReady until Cilium is up and
	// running and able to schedule endpoints.
	WriteCNIConfigurationWhenReady = "write-cni-conf-when-ready"

	// CNIExclusive tells the agent to remove other CNI configuration files
	CNIExclusive = "cni-exclusive"

	// CNIExternalRouting delegates endpoint routing to the chained CNI plugin.
	CNIExternalRouting = "cni-external-routing"

	// CNILogFile is the path to a log file (on the host) for the CNI plugin
	// binary to use for logging.
	CNILogFile = "cni-log-file"

	// EnableCiliumEndpointSlice enables the cilium endpoint slicing feature.
	EnableCiliumEndpointSlice = "enable-cilium-endpoint-slice"

	// IdentityManagementMode controls whether CiliumIdentities are managed by cilium-agent, cilium-operator, or both.
	IdentityManagementMode = "identity-management-mode"

	// EnableSourceIPVerification enables the source ip verification, defaults to true
	EnableSourceIPVerification = "enable-source-ip-verification"
)

const (
	// NodePortAccelerationDisabled means we do not accelerate NodePort via XDP
	NodePortAccelerationDisabled = XDPModeDisabled

	// NodePortAccelerationGeneric means we accelerate NodePort via generic XDP
	NodePortAccelerationGeneric = XDPModeGeneric

	// NodePortAccelerationNative means we accelerate NodePort via native XDP in the driver (preferred)
	NodePortAccelerationNative = XDPModeNative

	// NodePortAccelerationBestEffort means we accelerate NodePort via native XDP in the driver (preferred), but will skip devices without driver support
	NodePortAccelerationBestEffort = XDPModeBestEffort

	// PprofAddressAgent is the default value for pprof in the agent
	PprofAddressAgent = "localhost"

	// PprofPortAgent is the default value for pprof in the agent
	PprofPortAgent = 6060

	// IdentityManagementModeAgent means cilium-agent is solely responsible for managing CiliumIdentity.
	IdentityManagementModeAgent = "agent"

	// IdentityManagementModeOperator means cilium-operator is solely responsible for managing CiliumIdentity.
	IdentityManagementModeOperator = "operator"

	// IdentityManagementModeBoth means cilium-agent and cilium-operator both manage identities
	// (used only during migration between "agent" and "operator").
	IdentityManagementModeBoth = "both"
)

const (
	// BGPRouterIDAllocationModeDefault means the router-id is allocated per node
	BGPRouterIDAllocationModeDefault = "default"

	// BGPRouterIDAllocationModeIPPool means the router-id is allocated per IP pool
	BGPRouterIDAllocationModeIPPool = "ip-pool"
)

// getEnvName returns the environment variable to be used for the given option name.
func getEnvName(option string) string {
	under := strings.ReplaceAll(option, "-", "_")
	upper := strings.ToUpper(under)
	return ciliumEnvPrefix + upper
}

// BindEnv binds the option name with a deterministic generated environment
// variable which is based on the given optName. If the same optName is bound
// more than once, this function panics.
func BindEnv(vp *viper.Viper, optName string) {
	vp.BindEnv(optName, getEnvName(optName))
}

// BindEnvWithLegacyEnvFallback binds the given option name with either the same
// environment variable as BindEnv, if it's set, or with the given legacyEnvName.
//
// The function is used to work around the viper.BindEnv limitation that only
// one environment variable can be bound for an option, and we need multiple
// environment variables due to backward compatibility reasons.
func BindEnvWithLegacyEnvFallback(vp *viper.Viper, optName, legacyEnvName string) {
	envName := getEnvName(optName)
	if os.Getenv(envName) == "" {
		envName = legacyEnvName
	}
	vp.BindEnv(optName, envName)
}

// LogRegisteredSlogOptions logs all options that where bound to viper.
func LogRegisteredSlogOptions(vp *viper.Viper, entry *slog.Logger) {
	keys := vp.AllKeys()
	slices.Sort(keys)
	for _, k := range keys {
		ss := vp.GetStringSlice(k)
		if len(ss) == 0 {
			sm := vp.GetStringMap(k)
			for k, v := range sm {
				ss = append(ss, fmt.Sprintf("%s=%s", k, v))
			}
		}

		if len(ss) > 0 {
			entry.Info(fmt.Sprintf("  --%s='%s'", k, strings.Join(ss, ",")))
		} else {
			entry.Info(fmt.Sprintf("  --%s='%s'", k, vp.GetString(k)))
		}
	}
}

// DaemonConfig is the configuration used by Daemon.
type DaemonConfig struct {
	// Private sum of the config written to file. Used to check that the config is not changed
	// after.
	shaSum [32]byte

	CreationTime       time.Time
	BpfDir             string   // BPF template files directory
	LibDir             string   // Cilium library files directory
	RunDir             string   // Cilium runtime directory
	ExternalEnvoyProxy bool     // Whether Envoy is deployed as external DaemonSet or not
	LBDevInheritIPAddr string   // Device which IP addr used by bpf_host devices
	EnableXDPPrefilter bool     // Enable XDP-based prefiltering
	XDPMode            string   // XDP mode, values: { xdpdrv | xdpgeneric | none }
	EnableTCX          bool     // Enable attaching endpoint programs using tcx if the kernel supports it
	HostV4Addr         net.IP   // Host v4 address of the snooping device
	HostV6Addr         net.IP   // Host v6 address of the snooping device
	EncryptInterface   []string // Set of network facing interface to encrypt over
	EncryptNode        bool     // Set to true for encrypting node IP traffic

	DatapathMode string // Datapath mode
	RoutingMode  string // Routing mode

	DryMode bool // Do not create BPF maps, devices, ..

	// RestoreState enables restoring the state from previous running daemons.
	RestoreState bool

	KeepConfig bool // Keep configuration of existing endpoints when starting up.

	// AllowLocalhost defines when to allows the local stack to local endpoints
	// values: { auto | always | policy }
	AllowLocalhost string

	// StateDir is the directory where runtime state of endpoints is stored
	StateDir string

	// Options changeable at runtime
	Opts *IntOptions

	// Monitor contains the configuration for the node monitor.
	Monitor *models.MonitorStatus

	// AgentHealthPort is the TCP port for agent health status API
	AgentHealthPort int

	// ClusterHealthPort is the TCP port for cluster-wide network connectivity health API
	ClusterHealthPort int

	// ClusterMeshHealthPort is the TCP port for ClusterMesh apiserver health API
	ClusterMeshHealthPort int

	// AgentHealthRequireK8sConnectivity determines whether the agent health endpoint requires k8s connectivity
	AgentHealthRequireK8sConnectivity bool

	// IPv6ClusterAllocCIDR is the base CIDR used to allocate IPv6 node
	// CIDRs if allocation is not performed by an orchestration system
	IPv6ClusterAllocCIDR string

	// IPv6ClusterAllocCIDRBase is derived from IPv6ClusterAllocCIDR and
	// contains the CIDR without the mask, e.g. "fdfd::1/64" -> "fdfd::"
	//
	// This variable should never be written to, it is initialized via
	// DaemonConfig.Validate()
	IPv6ClusterAllocCIDRBase string

	// IPv6NAT46x64CIDR is the private base CIDR for the NAT46x64 gateway
	IPv6NAT46x64CIDR string

	// IPv6NAT46x64CIDRBase is derived from IPv6NAT46x64CIDR and contains
	// the IPv6 prefix with the masked bits zeroed out
	IPv6NAT46x64CIDRBase netip.Addr

	// K8sRequireIPv4PodCIDR requires the k8s node resource to specify the
	// IPv4 PodCIDR. Cilium will block bootstrapping until the information
	// is available.
	K8sRequireIPv4PodCIDR bool

	// K8sRequireIPv6PodCIDR requires the k8s node resource to specify the
	// IPv6 PodCIDR. Cilium will block bootstrapping until the information
	// is available.
	K8sRequireIPv6PodCIDR bool

	// MTU is the maximum transmission unit of the underlying network
	MTU int

	// RouteMetric is the metric used for the routes added to the cilium_host device
	RouteMetric int

	// ClusterName is the name of the cluster
	ClusterName string

	// ClusterID is the unique identifier of the cluster
	ClusterID uint32

	// CTMapEntriesGlobalTCP is the maximum number of conntrack entries
	// allowed in each TCP CT table for IPv4/IPv6.
	CTMapEntriesGlobalTCP int

	// CTMapEntriesGlobalAny is the maximum number of conntrack entries
	// allowed in each non-TCP CT table for IPv4/IPv6.
	CTMapEntriesGlobalAny int

	// CTMapEntriesTimeout* values configured by the user.
	CTMapEntriesTimeoutTCP         time.Duration
	CTMapEntriesTimeoutAny         time.Duration
	CTMapEntriesTimeoutSVCTCP      time.Duration
	CTMapEntriesTimeoutSVCTCPGrace time.Duration
	CTMapEntriesTimeoutSVCAny      time.Duration
	CTMapEntriesTimeoutSYN         time.Duration
	CTMapEntriesTimeoutFIN         time.Duration

	// MaxInternalTimerDelay sets a maximum on all periodic timers in
	// the agent in order to flush out timer-related bugs in the agent.
	MaxInternalTimerDelay time.Duration

	// MonitorAggregationInterval configures the interval between monitor
	// messages when monitor aggregation is enabled.
	MonitorAggregationInterval time.Duration

	// MonitorAggregationFlags determines which TCP flags that the monitor
	// aggregation ensures reports are generated for when monitor-aggregation
	// is enabled. Network byte-order.
	MonitorAggregationFlags uint16

	// BPFEventsDefaultRateLimit specifies limit of messages per second that can be written to
	// BPF events map. This limit is defined for all types of events except dbg.
	// The number of messages is averaged, meaning that if no messages were written
	// to the map over 5 seconds, it's possible to write more events than the value of rate limit
	// in the 6th second.
	//
	// If BPFEventsDefaultRateLimit > 0, non-zero value for BPFEventsDefaultBurstLimit must also be provided
	// lest the configuration is considered invalid.
	BPFEventsDefaultRateLimit uint32

	// BPFEventsDefaultBurstLimit specifies the maximum number of messages that can be written
	// to BPF events map in 1 second. This limit is defined for all types of events except dbg.
	//
	// If BPFEventsDefaultBurstLimit > 0, non-zero value for BPFEventsDefaultRateLimit must also be provided
	// lest the configuration is considered invalid.
	// If both burst and rate limit are 0 or not specified, no limit is imposed.
	BPFEventsDefaultBurstLimit uint32

	// BPFMapsDynamicSizeRatio is ratio of total system memory to use for
	// dynamic sizing of the CT, NAT, Neighbor and SockRevNAT BPF maps.
	BPFMapsDynamicSizeRatio float64

	// NATMapEntriesGlobal is the maximum number of NAT mappings allowed
	// in the BPF NAT table
	NATMapEntriesGlobal int

	// NeighMapEntriesGlobal is the maximum number of neighbor mappings
	// allowed in the BPF neigh table
	NeighMapEntriesGlobal int

	// AuthMapEntries is the maximum number of entries in the auth map.
	AuthMapEntries int

	// PolicyMapFullReconciliationInterval is the interval at which to perform
	// the full reconciliation of the endpoint policy map.
	PolicyMapFullReconciliationInterval time.Duration

	// DisableCiliumEndpointCRD disables the use of CiliumEndpoint CRD
	DisableCiliumEndpointCRD bool

	// MaxControllerInterval is the maximum value for a controller's
	// RunInterval. Zero means unlimited.
	MaxControllerInterval uint

	// HTTP403Message is the error message to return when a HTTP 403 is returned
	// by the proxy, if L7 policy is configured.
	HTTP403Message string

	ProcFs string

	// K8sNamespace is the name of the namespace in which Cilium is
	// deployed in when running in Kubernetes mode
	K8sNamespace string

	// AgentNotReadyNodeTaint is a node taint which prevents pods from being
	// scheduled. Once cilium is setup it is removed from the node. Mostly
	// used in cloud providers to prevent existing CNI plugins from managing
	// pods.
	AgentNotReadyNodeTaintKey string

	// EnableIPv4 is true when IPv4 is enabled
	EnableIPv4 bool

	// EnableIPv6 is true when IPv6 is enabled
	EnableIPv6 bool

	// EnableNat46X64Gateway is true when L3 based NAT46 and NAT64 translation is enabled
	EnableNat46X64Gateway bool

	// EnableIPv6NDP is true when NDP is enabled for IPv6
	EnableIPv6NDP bool

	// EnableSRv6 is true when SRv6 encapsulation support is enabled
	EnableSRv6 bool

	// SRv6EncapMode is the encapsulation mode for SRv6
	SRv6EncapMode string

	// EnableSCTP is true when SCTP support is enabled.
	EnableSCTP bool

	// IPv6MCastDevice is the name of device that joins IPv6's solicitation multicast group
	IPv6MCastDevice string

	// EnableL7Proxy is the option to enable L7 proxy
	EnableL7Proxy bool

	// BootIDFile is the file containing the boot ID of the node
	BootIDFile string

	// EnableEncryptionStrictMode enables strict mode for encryption
	EnableEncryptionStrictMode bool

	// EncryptionStrictModeCIDR is the CIDR to use for strict mode
	EncryptionStrictModeCIDR netip.Prefix

	// EncryptionStrictModeAllowRemoteNodeIdentities allows dynamic lookup of node identities.
	// This is required when tunneling is used
	// or direct routing is used and the node CIDR and pod CIDR overlap.
	EncryptionStrictModeAllowRemoteNodeIdentities bool

	// EnableL2Announcements enables L2 announcement of service IPs
	EnableL2Announcements bool

	// L2AnnouncerLeaseDuration, if a lease has not been renewed for X amount of time, a new leader can be chosen.
	L2AnnouncerLeaseDuration time.Duration
	// L2AnnouncerRenewDeadline, the leader will renew the lease every X amount of time.
	L2AnnouncerRenewDeadline time.Duration
	// L2AnnouncerRetryPeriod, on renew failure, retry after X amount of time.
	L2AnnouncerRetryPeriod time.Duration

	// CLI options

	BPFRoot                       string
	BPFSocketLBHostnsOnly         bool
	CGroupRoot                    string
	BPFCompileDebug               string
	ConfigFile                    string
	ConfigDir                     string
	Debug                         bool
	DebugVerbose                  []string
	EnableSocketLBTracing         bool
	EnableSocketLBPeer            bool
	EnablePolicy                  string
	EnableTracing                 bool
	EnableIPIPTermination         bool
	EnableUnreachableRoutes       bool
	FixedIdentityMapping          map[string]string
	FixedIdentityMappingValidator Validator `json:"-"`
	FixedZoneMapping              map[string]uint8
	ReverseFixedZoneMapping       map[uint8]string
	FixedZoneMappingValidator     Validator `json:"-"`
	IPv4Range                     string
	IPv6Range                     string
	IPv4ServiceRange              string
	IPv6ServiceRange              string
	K8sSyncTimeout                time.Duration
	AllocatorListTimeout          time.Duration
	LabelPrefixFile               string
	Labels                        []string
	LogDriver                     []string
	LogOpt                        map[string]string
	LogSystemLoadConfig           bool

	// Masquerade specifies whether or not to masquerade packets from endpoints
	// leaving the host.
	EnableRemoteNodeMasquerade  bool
	EnableIPv4Masquerade        bool
	EnableIPv6Masquerade        bool
	EnableBPFMasquerade         bool
	EnableMasqueradeRouteSource bool
	EnableIPMasqAgent           bool

	EnableBPFClockProbe    bool
	EnableEgressGateway    bool
	EnableEnvoyConfig      bool
	InstallIptRules        bool
	MonitorAggregation     string
	PreAllocateMaps        bool
	IPv6NodeAddr           string
	IPv4NodeAddr           string
	SocketPath             string
	TracePayloadlen        int
	TracePayloadlenOverlay int
	Version                string
	ToFQDNsMinTTL          int

	// DNSPolicyUnloadOnShutdown defines whether DNS policy rules should be unloaded on
	// graceful shutdown.
	DNSPolicyUnloadOnShutdown bool

	// ToFQDNsProxyPort is the user-configured global, shared, DNS listen port used
	// by the DNS Proxy. Both UDP and TCP are handled on the same port. When it
	// is 0 a random port will be assigned, and can be obtained from
	// DefaultDNSProxy below.
	ToFQDNsProxyPort int

	// ToFQDNsMaxIPsPerHost defines the maximum number of IPs to maintain
	// for each FQDN name in an endpoint's FQDN cache
	ToFQDNsMaxIPsPerHost int

	// ToFQDNsMaxIPsPerHost defines the maximum number of IPs to retain for
	// expired DNS lookups with still-active connections
	ToFQDNsMaxDeferredConnectionDeletes int

	// ToFQDNsIdleConnectionGracePeriod Time during which idle but
	// previously active connections with expired DNS lookups are
	// still considered alive
	ToFQDNsIdleConnectionGracePeriod time.Duration

	// FQDNRejectResponse is the dns-proxy response for invalid dns-proxy request
	FQDNRejectResponse string

	// FQDNProxyResponseMaxDelay The maximum time the DNS proxy holds an allowed
	// DNS response before sending it along. Responses are sent as soon as the
	// datapath is updated with the new IP information.
	FQDNProxyResponseMaxDelay time.Duration

	// FQDNRegexCompileLRUSize is the size of the FQDN regex compilation LRU.
	// Useful for heavy but repeated FQDN MatchName or MatchPattern use.
	FQDNRegexCompileLRUSize uint

	// Path to a file with DNS cache data to preload on startup
	ToFQDNsPreCache string

	// DNSProxyConcurrencyLimit limits parallel processing of DNS messages in
	// DNS proxy at any given point in time.
	DNSProxyConcurrencyLimit int

	// DNSProxyEnableTransparentMode enables transparent mode for the DNS proxy.
	DNSProxyEnableTransparentMode bool

	// DNSProxyLockCount is the array size containing mutexes which protect
	// against parallel handling of DNS response names.
	DNSProxyLockCount int

	// DNSProxyLockTimeout is timeout when acquiring the locks controlled by
	// DNSProxyLockCount.
	DNSProxyLockTimeout time.Duration

	// DNSProxySocketLingerTimeout defines how many seconds we wait for the connection
	// between the DNS proxy and the upstream server to be closed.
	DNSProxySocketLingerTimeout int

	// EnableBPFTProxy enables implementing proxy redirection via BPF
	// mechanisms rather than iptables rules.
	EnableBPFTProxy bool

	// EnableAutoDirectRouting enables installation of direct routes to
	// other nodes when available
	EnableAutoDirectRouting bool

	// DirectRoutingSkipUnreachable skips installation of direct routes
	// to nodes when they're not on the same L2
	DirectRoutingSkipUnreachable bool

	// EnableLocalNodeRoute controls installation of the route which points
	// the allocation prefix of the local node.
	EnableLocalNodeRoute bool

	// EnableHealthChecking enables health checking between nodes and
	// health endpoints
	EnableHealthChecking bool

	// EnableEndpointHealthChecking enables health checking between virtual
	// health endpoints
	EnableEndpointHealthChecking bool

	// EnableHealthCheckLoadBalancerIP enables health checking of LoadBalancerIP
	// by cilium
	EnableHealthCheckLoadBalancerIP bool

	// HealthCheckICMPFailureThreshold is the number of ICMP packets sent for each health
	// checking run. If at least an ICMP response is received, the node or endpoint
	// is marked as healthy.
	HealthCheckICMPFailureThreshold int

	// IdentityChangeGracePeriod is the grace period that needs to pass
	// before an endpoint that has changed its identity will start using
	// that new identity. During the grace period, the new identity has
	// already been allocated and other nodes in the cluster have a chance
	// to whitelist the new upcoming identity of the endpoint.
	IdentityChangeGracePeriod time.Duration

	// Maximum jitter time for CiliumIdentityAdd commentMore actions
	CiliumIdentityMaxJitter time.Duration

	// IdentityRestoreGracePeriod is the grace period that needs to pass before CIDR identities
	// restored during agent restart are released. If any of the restored identities remains
	// unused after this time, they will be removed from the IP cache. Any of the restored
	// identities that are used in network policies will remain in the IP cache until all such
	// policies are removed.
	//
	// The default is 30 seconds for k8s clusters, and 10 minutes for kvstore clusters
	IdentityRestoreGracePeriod time.Duration

	// EndpointQueueSize is the size of the EventQueue per-endpoint. A larger
	// queue means that more events can be buffered per-endpoint. This is useful
	// in the case where a cluster might be under high load for endpoint-related
	// events, specifically those which cause many regenerations.
	EndpointQueueSize int

	// ConntrackGCInterval is the connection tracking garbage collection
	// interval
	ConntrackGCInterval time.Duration

	// ConntrackGCMaxInterval if set limits the automatic GC interval calculation to
	// the specified maximum value.
	ConntrackGCMaxInterval time.Duration

	// ServiceLoopbackIPv4 is the address to use for service loopback SNAT
	ServiceLoopbackIPv4 string

	// ServiceLoopbackIPv6 is the address to use for service loopback SNAT
	ServiceLoopbackIPv6 string

	// LocalRouterIPv4 is the link-local IPv4 address used for Cilium's router device
	LocalRouterIPv4 string

	// LocalRouterIPv6 is the link-local IPv6 address used for Cilium's router device
	LocalRouterIPv6 string

	// EnableEndpointRoutes enables use of per endpoint routes
	EnableEndpointRoutes bool

	// Specifies whether to annotate the kubernetes nodes or not
	AnnotateK8sNode bool

	// EnableHealthDatapath enables IPIP health probes data path
	EnableHealthDatapath bool

	// EnableIPIPDevices enables the creation of IPIP devices for IPv4 and IPv6
	EnableIPIPDevices bool

	// EnableHostLegacyRouting enables the old routing path via stack.
	EnableHostLegacyRouting bool

	// NodePortNat46X64 indicates whether NAT46 / NAT64 can be used.
	NodePortNat46X64 bool

	// LoadBalancerIPIPSockMark enables sock-lb logic to force service traffic via IPIP
	LoadBalancerIPIPSockMark bool

	// LoadBalancerRSSv4CIDR defines the outer source IPv4 prefix for DSR/IPIP
	LoadBalancerRSSv4CIDR string
	LoadBalancerRSSv4     net.IPNet

	// LoadBalancerRSSv4CIDR defines the outer source IPv6 prefix for DSR/IPIP
	LoadBalancerRSSv6CIDR string
	LoadBalancerRSSv6     net.IPNet

	// LoadBalancerExternalControlPlane tells whether to not use kube-apiserver as
	// its control plane in lb-only mode.
	LoadBalancerExternalControlPlane bool

	// EnablePMTUDiscovery indicates whether to send ICMP fragmentation-needed
	// replies to the client (when needed).
	EnablePMTUDiscovery bool

	// NodePortAcceleration indicates whether NodePort should be accelerated
	// via XDP ("none", "generic", "native", or "best-effort")
	NodePortAcceleration string

	// NodePortBindProtection rejects bind requests to NodePort service ports
	NodePortBindProtection bool

	// EnableAutoProtectNodePortRange enables appending NodePort range to
	// net.ipv4.ip_local_reserved_ports if it overlaps with ephemeral port
	// range (net.ipv4.ip_local_port_range)
	EnableAutoProtectNodePortRange bool

	// AddressScopeMax controls the maximum address scope for addresses to be
	// considered local ones with HOST_ID in the ipcache
	AddressScopeMax int

	// EnableMKE enables MKE specific 'chaining' for kube-proxy replacement
	EnableMKE bool

	// CgroupPathMKE points to the cgroupv1 net_cls mount instance
	CgroupPathMKE string

	// EnableHostFirewall enables network policies for the host
	EnableHostFirewall bool

	// EnableLocalRedirectPolicy enables redirect policies to redirect traffic within nodes
	EnableLocalRedirectPolicy bool

	// Selection of BPF main clock source (ktime vs jiffies)
	ClockSource BPFClockSource

	// EnableIdentityMark enables setting the mark field with the identity for
	// local traffic. This may be disabled if chaining modes and Cilium use
	// conflicting marks.
	EnableIdentityMark bool

	// KernelHz is the HZ rate the kernel is operating in
	KernelHz int

	// ExcludeLocalAddresses excludes certain addresses to be recognized as
	// a local address
	ExcludeLocalAddresses []netip.Prefix

	// IPv4PodSubnets available subnets to be assign IPv4 addresses to pods from
	IPv4PodSubnets []*net.IPNet

	// IPv6PodSubnets available subnets to be assign IPv6 addresses to pods from
	IPv6PodSubnets []*net.IPNet

	// IPAM is the IPAM method to use
	IPAM string

	// IPAMMultiPoolPreAllocation defines the pre-allocation value for each IPAM pool
	IPAMMultiPoolPreAllocation map[string]string
	// IPAMDefaultIPPool the default IP Pool when using multi-pool
	IPAMDefaultIPPool string
	// AutoCreateCiliumNodeResource enables automatic creation of a
	// CiliumNode resource for the local node
	AutoCreateCiliumNodeResource bool

	// ExcludeNodeLabelPatterns allows for excluding unnecessary labels from being propagated from k8s node to cilium
	// node object. This allows for avoiding unnecessary events being broadcast to all nodes in the cluster.
	ExcludeNodeLabelPatterns []*regexp.Regexp

	// IPv4NativeRoutingCIDR describes a CIDR in which pod IPs are routable
	IPv4NativeRoutingCIDR *cidr.CIDR

	// IPv6NativeRoutingCIDR describes a CIDR in which pod IPs are routable
	IPv6NativeRoutingCIDR *cidr.CIDR

	// MasqueradeInterfaces is the selector used to select interfaces subject
	// to egress masquerading.
	MasqueradeInterfaces []string

	// PolicyTriggerInterval is the amount of time between when policy updates
	// are triggered.
	PolicyTriggerInterval time.Duration

	// IdentityAllocationMode specifies what mode to use for identity
	// allocation
	IdentityAllocationMode string

	// AllowICMPFragNeeded allows ICMP Fragmentation Needed type packets in
	// the network policy for cilium-agent.
	AllowICMPFragNeeded bool

	// Azure options

	// PolicyAuditMode enables non-drop mode for installed policies. In
	// audit mode packets affected by policies will not be dropped.
	// Policy related decisions can be checked via the policy verdict messages.
	PolicyAuditMode bool

	// PolicyAccounting enable policy accounting
	PolicyAccounting bool

	// EnableIPv4FragmentsTracking enables IPv4 fragments tracking for
	// L4-based lookups. Needs LRU map support.
	EnableIPv4FragmentsTracking bool

	// EnableIPv6FragmentsTracking enables IPv6 fragments tracking for
	// L4-based lookups. Needs LRU map support.
	EnableIPv6FragmentsTracking bool

	// FragmentsMapEntries is the maximum number of fragmented datagrams
	// that can simultaneously be tracked in order to retrieve their L4
	// ports for all fragments.
	FragmentsMapEntries int

	// SizeofCTElement is the size of an element (key + value) in the CT map.
	SizeofCTElement int

	// SizeofNATElement is the size of an element (key + value) in the NAT map.
	SizeofNATElement int

	// SizeofNeighElement is the size of an element (key + value) in the neigh
	// map.
	SizeofNeighElement int

	// SizeofSockRevElement is the size of an element (key + value) in the neigh
	// map.
	SizeofSockRevElement int

	// k8sEnableLeasesFallbackDiscovery enables k8s to fallback to API probing to check
	// for the support of Leases in Kubernetes when there is an error in discovering
	// API groups using Discovery API.
	// We require to check for Leases capabilities in operator only, which uses Leases for leader
	// election purposes in HA mode.
	// This is only enabled for cilium-operator
	K8sEnableLeasesFallbackDiscovery bool

	// EgressMultiHomeIPRuleCompat instructs Cilium to use a new scheme to
	// store rules and routes under ENI and Azure IPAM modes, if false.
	// Otherwise, it will use the old scheme.
	EgressMultiHomeIPRuleCompat bool

	// Install ingress/egress routes through uplink on host for Pods when working with
	// delegated IPAM plugin.
	InstallUplinkRoutesForDelegatedIPAM bool

	// InstallNoConntrackIptRules instructs Cilium to install Iptables rules to skip netfilter connection tracking on all pod traffic.
	InstallNoConntrackIptRules bool

	// ContainerIPLocalReservedPorts instructs the Cilium CNI plugin to reserve
	// the provided comma-separated list of ports in the container network namespace
	ContainerIPLocalReservedPorts string

	// BGPSecretsNamespace is the Kubernetes namespace to get BGP control plane secrets from.
	BGPSecretsNamespace string

	// EnableCiliumEndpointSlice enables the cilium endpoint slicing feature.
	EnableCiliumEndpointSlice bool

	// ARPPingKernelManaged denotes whether kernel can auto-refresh Neighbor entries
	ARPPingKernelManaged bool

	// VLANBPFBypass list of explicitly allowed VLAN id's for bpf logic bypass
	VLANBPFBypass []int

	// DisableExternalIPMigration disable externalIP mitigation (CVE-2020-8554)
	DisableExternalIPMitigation bool

	// EnableICMPRules enables ICMP-based rule support for Cilium Network Policies.
	EnableICMPRules bool

	// BypassIPAvailabilityUponRestore bypasses the IP availability error
	// within IPAM upon endpoint restore and allows the use of the restored IP
	// regardless of whether it's available in the pool.
	BypassIPAvailabilityUponRestore bool

	// EnableVTEP enable Cilium VXLAN VTEP integration
	EnableVTEP bool

	// VtepMask VTEP Mask
	VtepCidrMask net.IP

	// TCFilterPriority sets the priority of the cilium tc filter, enabling other
	// filters to be inserted prior to the cilium filter.
	TCFilterPriority uint16

	// Enables BGP control plane features.
	EnableBGPControlPlane bool

	// Enables BGP control plane status reporting.
	EnableBGPControlPlaneStatusReport bool

	// BGPRouterIDAllocationMode is the mode to allocate the BGP router-id.
	BGPRouterIDAllocationMode string

	// BGPRouterIDAllocationIPPool is the IP pool to allocate the BGP router-id from.
	BGPRouterIDAllocationIPPool string

	// BPFMapEventBuffers has configuration on what BPF map event buffers to enabled
	// and configuration options for those.
	BPFMapEventBuffers          map[string]string
	BPFMapEventBuffersValidator Validator `json:"-"`
	bpfMapEventConfigs          BPFEventBufferConfigs

	// BPFDistributedLRU enables per-CPU distributed backend memory
	BPFDistributedLRU bool

	// BPFEventsDropEnabled controls whether the Cilium datapath exposes "drop" events to Cilium monitor and Hubble.
	BPFEventsDropEnabled bool

	// BPFEventsPolicyVerdictEnabled controls whether the Cilium datapath exposes "policy verdict" events to Cilium monitor and Hubble.
	BPFEventsPolicyVerdictEnabled bool

	// BPFEventsTraceEnabled  controls whether the Cilium datapath exposes "trace" events to Cilium monitor and Hubble.
	BPFEventsTraceEnabled bool

	// BPFConntrackAccounting controls whether CT accounting for packets and bytes is enabled.
	BPFConntrackAccounting bool

	// IPAMCiliumNodeUpdateRate is the maximum rate at which the CiliumNode custom
	// resource is updated.
	IPAMCiliumNodeUpdateRate time.Duration

	// EnableK8sNetworkPolicy enables support for K8s NetworkPolicy.
	EnableK8sNetworkPolicy bool

	// EnableCiliumNetworkPolicy enables support for Cilium Network Policy.
	EnableCiliumNetworkPolicy bool

	// EnableCiliumClusterwideNetworkPolicy enables support for Cilium Clusterwide
	// Network Policy.
	EnableCiliumClusterwideNetworkPolicy bool

	// PolicyCIDRMatchMode is the list of entities that can be selected by CIDR policy.
	// Currently supported values:
	// - nodes
	PolicyCIDRMatchMode []string

	// MaxConnectedClusters sets the maximum number of clusters that can be
	// connected in a clustermesh.
	// The value is used to determine the bit allocation for cluster ID and
	// identity in a numeric identity. Values > 255 will decrease the number of
	// allocatable identities.
	MaxConnectedClusters uint32

	// ForceDeviceRequired enforces the attachment of BPF programs on native device.
	ForceDeviceRequired bool

	// ServiceNoBackendResponse determines how we handle traffic to a service with no backends.
	ServiceNoBackendResponse string

	// PolicyDenyResponse determines how we handle pod egress traffic denied by network policy.
	PolicyDenyResponse string

	// EnableNodeSelectorLabels enables use of the node label based identity
	EnableNodeSelectorLabels bool

	// NodeLabels is the list of label prefixes used to determine identity of a node (requires enabling of
	// EnableNodeSelectorLabels)
	NodeLabels []string

	// EnableSocketLBPodConnectionTermination enables the termination of connections from pods
	// to deleted service backends when socket-LB is enabled
	EnableSocketLBPodConnectionTermination bool

	// EnableNonDefaultDenyPolicies allows policies to define whether they are operating in default-deny mode
	EnableNonDefaultDenyPolicies bool

	// EnableSourceIPVerification enables the source ip validation of connection from endpoints to endpoints
	EnableSourceIPVerification bool

	// EnableEndpointLockdownOnPolicyOverflow enables endpoint lockdown when an endpoint's
	// policy map overflows.
	EnableEndpointLockdownOnPolicyOverflow bool

	// ConnectivityProbeFrequencyRatio is the ratio of the connectivity probe frequency vs resource consumption
	ConnectivityProbeFrequencyRatio float64

	// EnableExtendedIPProtocols controls whether traffic with extended IP protocols is supported in datapath
	EnableExtendedIPProtocols bool

	// IPTracingOptionType determines whether to enable IP tracing, and if enabled what option type to use.
	IPTracingOptionType uint
}

var (
	// Config represents the daemon configuration
	Config = &DaemonConfig{
		CreationTime:                    time.Now(),
		Opts:                            NewIntOptions(&DaemonOptionLibrary),
		Monitor:                         &models.MonitorStatus{Cpus: int64(runtime.NumCPU()), Npages: 64, Pagesize: int64(os.Getpagesize()), Lost: 0, Unknown: 0},
		IPv6ClusterAllocCIDR:            defaults.IPv6ClusterAllocCIDR,
		IPv6ClusterAllocCIDRBase:        defaults.IPv6ClusterAllocCIDRBase,
		IPAMDefaultIPPool:               defaults.IPAMDefaultIPPool,
		EnableHealthChecking:            defaults.EnableHealthChecking,
		EnableEndpointHealthChecking:    defaults.EnableEndpointHealthChecking,
		EnableHealthCheckLoadBalancerIP: defaults.EnableHealthCheckLoadBalancerIP,
		HealthCheckICMPFailureThreshold: defaults.HealthCheckICMPFailureThreshold,
		EnableIPv4:                      defaults.EnableIPv4,
		EnableIPv6:                      defaults.EnableIPv6,
		EnableIPv6NDP:                   defaults.EnableIPv6NDP,
		EnableSCTP:                      defaults.EnableSCTP,
		EnableL7Proxy:                   defaults.EnableL7Proxy,
		ToFQDNsMaxIPsPerHost:            defaults.ToFQDNsMaxIPsPerHost,
		IdentityChangeGracePeriod:       defaults.IdentityChangeGracePeriod,
		CiliumIdentityMaxJitter:         defaults.CiliumIdentityMaxJitter,
		IdentityRestoreGracePeriod:      defaults.IdentityRestoreGracePeriodK8s,
		FixedIdentityMapping:            make(map[string]string),
		LogOpt:                          make(map[string]string),
		ServiceLoopbackIPv4:             defaults.ServiceLoopbackIPv4,
		ServiceLoopbackIPv6:             defaults.ServiceLoopbackIPv6,
		EnableEndpointRoutes:            defaults.EnableEndpointRoutes,
		AnnotateK8sNode:                 defaults.AnnotateK8sNode,
		AutoCreateCiliumNodeResource:    defaults.AutoCreateCiliumNodeResource,
		IdentityAllocationMode:          IdentityAllocationModeKVstore,
		AllowICMPFragNeeded:             defaults.AllowICMPFragNeeded,
		AllocatorListTimeout:            defaults.AllocatorListTimeout,
		EnableICMPRules:                 defaults.EnableICMPRules,

		K8sEnableLeasesFallbackDiscovery: defaults.K8sEnableLeasesFallbackDiscovery,

		EnableVTEP:                           defaults.EnableVTEP,
		EnableBGPControlPlane:                defaults.EnableBGPControlPlane,
		EnableK8sNetworkPolicy:               defaults.EnableK8sNetworkPolicy,
		EnableCiliumNetworkPolicy:            defaults.EnableCiliumNetworkPolicy,
		EnableCiliumClusterwideNetworkPolicy: defaults.EnableCiliumClusterwideNetworkPolicy,
		PolicyCIDRMatchMode:                  defaults.PolicyCIDRMatchMode,
		MaxConnectedClusters:                 defaults.MaxConnectedClusters,

		BPFDistributedLRU:             defaults.BPFDistributedLRU,
		BPFEventsDropEnabled:          defaults.BPFEventsDropEnabled,
		BPFEventsPolicyVerdictEnabled: defaults.BPFEventsPolicyVerdictEnabled,
		BPFEventsTraceEnabled:         defaults.BPFEventsTraceEnabled,
		BPFConntrackAccounting:        defaults.BPFConntrackAccounting,
		EnableEnvoyConfig:             defaults.EnableEnvoyConfig,

		EnableNonDefaultDenyPolicies: defaults.EnableNonDefaultDenyPolicies,

		EnableSourceIPVerification: defaults.EnableSourceIPVerification,

		ConnectivityProbeFrequencyRatio: defaults.ConnectivityProbeFrequencyRatio,

		IPTracingOptionType: defaults.IPTracingOptionType,
	}
)

// IsExcludedLocalAddress returns true if the specified IP matches one of the
// excluded local IP ranges
func (c *DaemonConfig) IsExcludedLocalAddress(addr netip.Addr) bool {
	for _, prefix := range c.ExcludeLocalAddresses {
		if prefix.Contains(addr) {
			return true
		}
	}
	return false
}

// IsPodSubnetsDefined returns true if encryption subnets should be configured at init time.
func (c *DaemonConfig) IsPodSubnetsDefined() bool {
	return len(c.IPv4PodSubnets) > 0 || len(c.IPv6PodSubnets) > 0
}

// NodeConfigFile is the name of the C header which contains the node's
// network parameters.
const nodeConfigFile = "node_config.h"

// GetNodeConfigPath returns the full path of the NodeConfigFile.
func (c *DaemonConfig) GetNodeConfigPath() string {
	return filepath.Join(c.GetGlobalsDir(), nodeConfigFile)
}

// GetGlobalsDir returns the path for the globals directory.
func (c *DaemonConfig) GetGlobalsDir() string {
	return filepath.Join(c.StateDir, "globals")
}

// AlwaysAllowLocalhost returns true if the daemon has the option set that
// localhost can always reach local endpoints
func (c *DaemonConfig) AlwaysAllowLocalhost() bool {
	switch c.AllowLocalhost {
	case AllowLocalhostAlways:
		return true
	case AllowLocalhostAuto, AllowLocalhostPolicy:
		return false
	default:
		return false
	}
}

// TunnelingEnabled returns true if tunneling is enabled.
func (c *DaemonConfig) TunnelingEnabled() bool {
	// We check if routing mode is not native rather than checking if it's
	// tunneling because, in unit tests, RoutingMode is usually not set and we
	// would like for TunnelingEnabled to default to the actual default
	// (tunneling is enabled) in that case.
	return c.RoutingMode != RoutingModeNative
}

// AreDevicesRequired returns true if the agent needs to attach to the native
// devices to implement some features.
func (c *DaemonConfig) AreDevicesRequired(kprCfg kpr.KPRConfig, wireguardEnabled, ipsecEnabled bool) bool {
	return kprCfg.KubeProxyReplacement || c.EnableBPFMasquerade || c.EnableHostFirewall || wireguardEnabled ||
		c.EnableL2Announcements || c.ForceDeviceRequired || ipsecEnabled
}

// NeedIngressOnWireGuardDevice returns true if the agent needs to attach
// cil_from_wireguard on the Ingress of Cilium's WireGuard device
func (c *DaemonConfig) NeedIngressOnWireGuardDevice(kprCfg kpr.KPRConfig, wireguardEnabled bool) bool {
	if !wireguardEnabled {
		return false
	}

	// In native routing mode we want to deliver packets to local endpoints
	// straight from BPF, without passing through the stack.
	// This matches overlay mode (where bpf_overlay would handle the delivery)
	// and native routing mode without encryption (where bpf_host at the native
	// device would handle the delivery).
	if !c.TunnelingEnabled() {
		return true
	}

	// When WG & encrypt-node are on, a NodePort BPF to-be forwarded request
	// to a remote node running a selected service endpoint must be encrypted.
	// To make the NodePort's rev-{S,D}NAT translations to happen for a reply
	// from the remote node, we need to attach bpf_host to the Cilium's WG
	// netdev (otherwise, the WG netdev after decrypting the reply will pass
	// it to the stack which drops the packet).
	if kprCfg.KubeProxyReplacement && c.EncryptNode {
		return true
	}

	return false
}

// NeedEgressOnWireGuardDevice returns true if the agent needs to attach
// cil_to_wireguard on the Egress of Cilium's WireGuard device
func (c *DaemonConfig) NeedEgressOnWireGuardDevice(kprCfg kpr.KPRConfig, wireguardEnabled bool) bool {
	if !wireguardEnabled {
		return false
	}

	// No need to handle rev-NAT xlations in wireguard with tunneling enabled.
	if c.TunnelingEnabled() {
		return false
	}

	// Attaching cil_to_wireguard to cilium_wg0 egress is required for handling
	// the rev-NAT xlations when encrypting KPR traffic.
	if c.EnableL7Proxy && kprCfg.KubeProxyReplacement {
		return true
	}

	return false
}

// MasqueradingEnabled returns true if either IPv4 or IPv6 masquerading is enabled.
func (c *DaemonConfig) MasqueradingEnabled() bool {
	return c.EnableIPv4Masquerade || c.EnableIPv6Masquerade
}

// IptablesMasqueradingIPv4Enabled returns true if iptables-based
// masquerading is enabled for IPv4.
func (c *DaemonConfig) IptablesMasqueradingIPv4Enabled() bool {
	return !c.EnableBPFMasquerade && c.EnableIPv4Masquerade
}

// IptablesMasqueradingIPv6Enabled returns true if iptables-based
// masquerading is enabled for IPv6.
func (c *DaemonConfig) IptablesMasqueradingIPv6Enabled() bool {
	return !c.EnableBPFMasquerade && c.EnableIPv6Masquerade
}

// IptablesMasqueradingEnabled returns true if iptables-based
// masquerading is enabled.
func (c *DaemonConfig) IptablesMasqueradingEnabled() bool {
	return c.IptablesMasqueradingIPv4Enabled() || c.IptablesMasqueradingIPv6Enabled()
}

// NodeIpsetNeeded returns true if a node ipsets should be used to skip
// masquerading for traffic to cluster nodes.
func (c *DaemonConfig) NodeIpsetNeeded() bool {
	return !c.TunnelingEnabled() && c.IptablesMasqueradingEnabled()
}

// NodeEncryptionEnabled returns true if node encryption is enabled
func (c *DaemonConfig) NodeEncryptionEnabled() bool {
	return c.EncryptNode
}

// IPv4Enabled returns true if IPv4 is enabled
func (c *DaemonConfig) IPv4Enabled() bool {
	return c.EnableIPv4
}

// IPv6Enabled returns true if IPv6 is enabled
func (c *DaemonConfig) IPv6Enabled() bool {
	return c.EnableIPv6
}

// IPv6NDPEnabled returns true if IPv6 NDP support is enabled
func (c *DaemonConfig) IPv6NDPEnabled() bool {
	return c.EnableIPv6NDP
}

// SCTPEnabled returns true if SCTP support is enabled
func (c *DaemonConfig) SCTPEnabled() bool {
	return c.EnableSCTP
}

// HealthCheckingEnabled returns true if health checking is enabled
func (c *DaemonConfig) HealthCheckingEnabled() bool {
	return c.EnableHealthChecking
}

// IPAMMode returns the IPAM mode
func (c *DaemonConfig) IPAMMode() string {
	return strings.ToLower(c.IPAM)
}

// TracingEnabled returns if tracing policy (outlining which rules apply to a
// specific set of labels) is enabled.
func (c *DaemonConfig) TracingEnabled() bool {
	return c.Opts.IsEnabled(PolicyTracing)
}

// UnreachableRoutesEnabled returns true if unreachable routes is enabled
func (c *DaemonConfig) UnreachableRoutesEnabled() bool {
	return c.EnableUnreachableRoutes
}

// CiliumNamespaceName returns the name of the namespace in which Cilium is
// deployed in
func (c *DaemonConfig) CiliumNamespaceName() string {
	return c.K8sNamespace
}

// AgentNotReadyNodeTaintValue returns the value of the taint key that cilium agents
// will manage on their nodes
func (c *DaemonConfig) AgentNotReadyNodeTaintValue() string {
	if c.AgentNotReadyNodeTaintKey != "" {
		return c.AgentNotReadyNodeTaintKey
	} else {
		return defaults.AgentNotReadyNodeTaint
	}
}

// K8sNetworkPolicyEnabled returns true if cilium agent needs to support K8s NetworkPolicy, false otherwise.
func (c *DaemonConfig) K8sNetworkPolicyEnabled() bool {
	return c.EnableK8sNetworkPolicy
}

func (c *DaemonConfig) PolicyCIDRMatchesNodes() bool {
	return slices.Contains(c.PolicyCIDRMatchMode, "nodes")
}

// PerNodeLabelsEnabled returns true if per-node labels feature
// is enabled
func (c *DaemonConfig) PerNodeLabelsEnabled() bool {
	return c.EnableNodeSelectorLabels
}

func (c *DaemonConfig) validatePolicyCIDRMatchMode() error {
	// Currently, the only acceptable values is "nodes".
	for _, mode := range c.PolicyCIDRMatchMode {
		switch mode {
		case "nodes":
			continue
		default:
			return fmt.Errorf("unknown CIDR match mode: %s", mode)
		}
	}
	return nil
}

// DirectRoutingDeviceRequired return whether the Direct Routing Device is needed under
// the current configuration.
func (c *DaemonConfig) DirectRoutingDeviceRequired(kprCfg kpr.KPRConfig, wireguardEnabled bool) bool {
	// BPF NodePort and BPF Host Routing are using the direct routing device now.
	// When tunneling is enabled, node-to-node redirection will be done by tunneling.
	BPFHostRoutingEnabled := !c.EnableHostLegacyRouting

	// XDP needs IPV4_DIRECT_ROUTING when building tunnel headers:
	if kprCfg.KubeProxyReplacement && c.NodePortAcceleration != NodePortAccelerationDisabled {
		return true
	}

	return kprCfg.KubeProxyReplacement || BPFHostRoutingEnabled || wireguardEnabled
}

func (c *DaemonConfig) validateIPv6ClusterAllocCIDR() error {
	ip, cidr, err := net.ParseCIDR(c.IPv6ClusterAllocCIDR)
	if err != nil {
		return err
	}

	if ones, _ := cidr.Mask.Size(); ones != 64 {
		return fmt.Errorf("Prefix length must be /64")
	}

	c.IPv6ClusterAllocCIDRBase = ip.Mask(cidr.Mask).String()

	return nil
}

func (c *DaemonConfig) validateIPv6NAT46x64CIDR() error {
	parsedPrefix, err := netip.ParsePrefix(c.IPv6NAT46x64CIDR)
	if err != nil {
		return err
	}
	if parsedPrefix.Bits() != 96 {
		return fmt.Errorf("Prefix length must be /96")
	}

	c.IPv6NAT46x64CIDRBase = parsedPrefix.Masked().Addr()
	return nil
}

func (c *DaemonConfig) validateContainerIPLocalReservedPorts() error {
	if c.ContainerIPLocalReservedPorts == "" || c.ContainerIPLocalReservedPorts == defaults.ContainerIPLocalReservedPortsAuto {
		return nil
	}

	if regexp.MustCompile(`^(\d+(-\d+)?)(,\d+(-\d+)?)*$`).MatchString(c.ContainerIPLocalReservedPorts) {
		return nil
	}

	return fmt.Errorf("Invalid comma separated list of of ranges for %s option", ContainerIPLocalReservedPorts)
}

// Validate validates the daemon configuration
func (c *DaemonConfig) Validate(vp *viper.Viper) error {
	if err := c.validateIPv6ClusterAllocCIDR(); err != nil {
		return fmt.Errorf("unable to parse CIDR value '%s' of option --%s: %w",
			c.IPv6ClusterAllocCIDR, IPv6ClusterAllocCIDRName, err)
	}

	if err := c.validateIPv6NAT46x64CIDR(); err != nil {
		return fmt.Errorf("unable to parse internal CIDR value '%s': %w",
			c.IPv6NAT46x64CIDR, err)
	}

	if c.MTU < 0 {
		return fmt.Errorf("MTU '%d' cannot be negative", c.MTU)
	}

	if c.RouteMetric < 0 {
		return fmt.Errorf("RouteMetric '%d' cannot be negative", c.RouteMetric)
	}

	if c.IPAM == ipamOption.IPAMENI && c.EnableIPv6 {
		return fmt.Errorf("IPv6 cannot be enabled in ENI IPAM mode")
	}

	if c.EnableIPv6NDP {
		if !c.EnableIPv6 {
			return fmt.Errorf("IPv6NDP cannot be enabled when IPv6 is not enabled")
		}
		if len(c.IPv6MCastDevice) == 0 {
			return fmt.Errorf("IPv6NDP cannot be enabled without %s", IPv6MCastDevice)
		}
	}

	switch c.RoutingMode {
	case RoutingModeNative, RoutingModeTunnel:
	default:
		return fmt.Errorf("invalid routing mode %q, valid modes = {%q, %q}",
			c.RoutingMode, RoutingModeTunnel, RoutingModeNative)
	}

	cinfo := clustermeshTypes.ClusterInfo{
		ID:                   c.ClusterID,
		Name:                 c.ClusterName,
		MaxConnectedClusters: c.MaxConnectedClusters,
	}
	if err := cinfo.InitClusterIDMax(); err != nil {
		return err
	}
	if err := cinfo.Validate(); err != nil {
		return err
	}

	if err := c.checkMapSizeLimits(); err != nil {
		return err
	}

	if err := c.checkIPv4NativeRoutingCIDR(); err != nil {
		return err
	}

	if err := c.checkIPv6NativeRoutingCIDR(); err != nil {
		return err
	}

	if err := c.checkIPAMDelegatedPlugin(); err != nil {
		return err
	}

	if c.EnableVTEP {
		err := c.validateVTEP(vp)
		if err != nil {
			return fmt.Errorf("Failed to validate VTEP configuration: %w", err)
		}
	}

	if err := c.validatePolicyCIDRMatchMode(); err != nil {
		return err
	}

	if err := c.validateContainerIPLocalReservedPorts(); err != nil {
		return err
	}

	return nil
}

// ReadDirConfig reads the given directory and returns a map that maps the
// filename to the contents of that file.
func ReadDirConfig(logger *slog.Logger, dirName string) (map[string]any, error) {
	m := map[string]any{}
	files, err := os.ReadDir(dirName)
	if err != nil && !os.IsNotExist(err) {
		return nil, fmt.Errorf("unable to read configuration directory: %w", err)
	}
	for _, f := range files {
		if f.IsDir() {
			continue
		}
		fName := filepath.Join(dirName, f.Name())

		// the file can still be a symlink to a directory
		if f.Type()&os.ModeSymlink == 0 {
			absFileName, err := filepath.EvalSymlinks(fName)
			if err != nil {
				logger.Warn("Unable to read configuration file",
					logfields.Error, err,
					logfields.File, absFileName,
				)
				continue
			}
			fName = absFileName
		}

		fi, err := os.Stat(fName)
		if err != nil {
			logger.Warn("Unable to read configuration file",
				logfields.Error, err,
				logfields.File, fName,
			)
			continue
		}
		if fi.Mode().IsDir() {
			continue
		}

		b, err := os.ReadFile(fName)
		if err != nil {
			logger.Warn("Unable to read configuration file",
				logfields.Error, err,
				logfields.File, fName,
			)
			continue
		}
		m[f.Name()] = string(bytes.TrimSpace(b))
	}
	return m, nil
}

// MergeConfig merges the given configuration map with viper's configuration.
func MergeConfig(vp *viper.Viper, m map[string]any) error {
	err := vp.MergeConfigMap(m)
	if err != nil {
		return fmt.Errorf("unable to read merge directory configuration: %w", err)
	}
	return nil
}

// ReplaceDeprecatedFields replaces the deprecated options set with the new set
// of options that overwrite the deprecated ones.
// This function replaces the deprecated fields used by environment variables
// with a different name than the option they are setting. This also replaces
// the deprecated names used in the Kubernetes ConfigMap.
// Once we remove them from this function we also need to remove them from
// daemon_main.go and warn users about the old environment variable nor the
// option in the configuration map have any effect.
func ReplaceDeprecatedFields(m map[string]any) {
	deprecatedFields := map[string]string{
		"monitor-aggregation-level":   MonitorAggregationName,
		"ct-global-max-entries-tcp":   CTMapEntriesGlobalTCPName,
		"ct-global-max-entries-other": CTMapEntriesGlobalAnyName,
	}
	for deprecatedOption, newOption := range deprecatedFields {
		if deprecatedValue, ok := m[deprecatedOption]; ok {
			if _, ok := m[newOption]; !ok {
				m[newOption] = deprecatedValue
			}
		}
	}
}

func (c *DaemonConfig) parseExcludedLocalAddresses(s []string) error {
	for _, ipString := range s {
		prefix, err := netip.ParsePrefix(ipString)
		if err != nil {
			return fmt.Errorf("unable to parse excluded local address %s: %w", ipString, err)
		}
		c.ExcludeLocalAddresses = append(c.ExcludeLocalAddresses, prefix)
	}
	return nil
}

// SetupLogging sets all logging-related options with the values from viper,
// then setup logging based on these options and the given tag.
//
// This allows initializing logging as early as possible, then log entries
// produced below in Populate can honor the requested logging configurations.
func (c *DaemonConfig) SetupLogging(vp *viper.Viper, tag string) {
	c.Debug = vp.GetBool(DebugArg)
	c.LogDriver = vp.GetStringSlice(LogDriver)

	if m, err := command.GetStringMapStringE(vp, LogOpt); err != nil {
		// slogloggercheck: log fatal errors using the default logger before it's initialized.
		logging.Fatal(logging.DefaultSlogLogger, fmt.Sprintf("unable to parse %s", LogOpt), logfields.Error, err)
	} else {
		c.LogOpt = m
	}

	if err := logging.SetupLogging(c.LogDriver, c.LogOpt, tag, c.Debug); err != nil {
		// slogloggercheck: log fatal errors using the default logger before it's initialized.
		logging.Fatal(logging.DefaultSlogLogger, "Unable to set up logging", logfields.Error, err)
	}
}

// Populate sets all non-logging options with the values from viper.
//
// This function may emit logs. Consider calling SetupLogging before this
// to make sure that they honor logging-related options.
func (c *DaemonConfig) Populate(logger *slog.Logger, vp *viper.Viper) {
	var err error

	c.AgentHealthPort = vp.GetInt(AgentHealthPort)
	c.ClusterHealthPort = vp.GetInt(ClusterHealthPort)
	c.ClusterMeshHealthPort = vp.GetInt(ClusterMeshHealthPort)
	c.AllowICMPFragNeeded = vp.GetBool(AllowICMPFragNeeded)
	c.AllowLocalhost = vp.GetString(AllowLocalhost)
	c.AnnotateK8sNode = vp.GetBool(AnnotateK8sNode)
	c.AutoCreateCiliumNodeResource = vp.GetBool(AutoCreateCiliumNodeResource)
	c.BPFRoot = vp.GetString(BPFRoot)
	c.CGroupRoot = vp.GetString(CGroupRoot)
	c.ClusterID = vp.GetUint32(clustermeshTypes.OptClusterID)
	c.ClusterName = vp.GetString(clustermeshTypes.OptClusterName)
	c.MaxConnectedClusters = vp.GetUint32(clustermeshTypes.OptMaxConnectedClusters)
	c.DatapathMode = vp.GetString(DatapathMode)
	c.DebugVerbose = vp.GetStringSlice(DebugVerbose)
	c.EnableIPv4 = vp.GetBool(EnableIPv4Name)
	c.EnableIPv6 = vp.GetBool(EnableIPv6Name)
	c.EnableIPv6NDP = vp.GetBool(EnableIPv6NDPName)
	c.EnableSRv6 = vp.GetBool(EnableSRv6)
	c.SRv6EncapMode = vp.GetString(SRv6EncapModeName)
	c.EnableSCTP = vp.GetBool(EnableSCTPName)
	c.IPv6MCastDevice = vp.GetString(IPv6MCastDevice)
	c.EnableL2Announcements = vp.GetBool(EnableL2Announcements)
	c.L2AnnouncerLeaseDuration = vp.GetDuration(L2AnnouncerLeaseDuration)
	c.L2AnnouncerRenewDeadline = vp.GetDuration(L2AnnouncerRenewDeadline)
	c.L2AnnouncerRetryPeriod = vp.GetDuration(L2AnnouncerRetryPeriod)
	c.EnableXDPPrefilter = vp.GetBool(EnableXDPPrefilter)
	c.EnableTCX = vp.GetBool(EnableTCX)
	c.DisableCiliumEndpointCRD = vp.GetBool(DisableCiliumEndpointCRDName)
	c.MasqueradeInterfaces = vp.GetStringSlice(MasqueradeInterfaces)
	c.BPFSocketLBHostnsOnly = vp.GetBool(BPFSocketLBHostnsOnly)
	c.EnableSocketLBTracing = vp.GetBool(EnableSocketLBTracing)
	c.EnableSocketLBPodConnectionTermination = vp.GetBool(EnableSocketLBPodConnectionTermination)
	c.EnableBPFTProxy = vp.GetBool(EnableBPFTProxy)
	c.EnableAutoDirectRouting = vp.GetBool(EnableAutoDirectRoutingName)
	c.DirectRoutingSkipUnreachable = vp.GetBool(DirectRoutingSkipUnreachableName)
	c.EnableEndpointRoutes = vp.GetBool(EnableEndpointRoutes)
	c.EnableHealthChecking = vp.GetBool(EnableHealthChecking)
	c.EnableEndpointHealthChecking = vp.GetBool(EnableEndpointHealthChecking)
	c.EnableHealthCheckLoadBalancerIP = vp.GetBool(EnableHealthCheckLoadBalancerIP)
	c.HealthCheckICMPFailureThreshold = vp.GetInt(HealthCheckICMPFailureThreshold)
	c.EnableLocalNodeRoute = vp.GetBool(EnableLocalNodeRoute)
	c.EnablePolicy = strings.ToLower(vp.GetString(EnablePolicy))
	c.EnableL7Proxy = vp.GetBool(EnableL7Proxy)
	c.EnableTracing = vp.GetBool(EnableTracing)
	c.EnableIPIPTermination = vp.GetBool(EnableIPIPTermination)
	c.EnableIPIPDevices = c.EnableIPIPTermination
	c.EnableUnreachableRoutes = vp.GetBool(EnableUnreachableRoutes)
	c.EnableHostLegacyRouting = vp.GetBool(EnableHostLegacyRouting)
	c.NodePortBindProtection = vp.GetBool(NodePortBindProtection)
	c.NodePortNat46X64 = vp.GetBool(LoadBalancerNat46X64)
	c.EnableAutoProtectNodePortRange = vp.GetBool(EnableAutoProtectNodePortRange)
	c.EnableMKE = vp.GetBool(EnableMKE)
	c.CgroupPathMKE = vp.GetString(CgroupPathMKE)
	c.EnableHostFirewall = vp.GetBool(EnableHostFirewall)
	c.EnableLocalRedirectPolicy = vp.GetBool(EnableLocalRedirectPolicy)
	c.EncryptInterface = vp.GetStringSlice(EncryptInterface)
	c.EncryptNode = vp.GetBool(EncryptNode)
	c.IdentityChangeGracePeriod = vp.GetDuration(IdentityChangeGracePeriod)
	c.CiliumIdentityMaxJitter = vp.GetDuration(CiliumIdentityMaxJitter)
	c.IdentityRestoreGracePeriod = vp.GetDuration(IdentityRestoreGracePeriod)
	c.IPAM = vp.GetString(IPAM)
	c.IPAMDefaultIPPool = vp.GetString(IPAMDefaultIPPool)
	c.IPv4Range = vp.GetString(IPv4Range)
	c.IPv4NodeAddr = vp.GetString(IPv4NodeAddr)
	c.IPv4ServiceRange = vp.GetString(IPv4ServiceRange)
	c.IPv6ClusterAllocCIDR = vp.GetString(IPv6ClusterAllocCIDRName)
	c.IPv6NodeAddr = vp.GetString(IPv6NodeAddr)
	c.IPv6Range = vp.GetString(IPv6Range)
	c.IPv6ServiceRange = vp.GetString(IPv6ServiceRange)
	c.K8sRequireIPv4PodCIDR = vp.GetBool(K8sRequireIPv4PodCIDRName)
	c.K8sRequireIPv6PodCIDR = vp.GetBool(K8sRequireIPv6PodCIDRName)
	c.K8sSyncTimeout = vp.GetDuration(K8sSyncTimeoutName)
	c.AllocatorListTimeout = vp.GetDuration(AllocatorListTimeoutName)
	c.KeepConfig = vp.GetBool(KeepConfig)
	c.LabelPrefixFile = vp.GetString(LabelPrefixFile)
	c.Labels = vp.GetStringSlice(Labels)
	c.LibDir = vp.GetString(LibDir)
	c.LogSystemLoadConfig = vp.GetBool(LogSystemLoadConfigName)
	c.ServiceLoopbackIPv4 = vp.GetString(ServiceLoopbackIPv4)
	c.ServiceLoopbackIPv6 = vp.GetString(ServiceLoopbackIPv6)
	c.LocalRouterIPv4 = vp.GetString(LocalRouterIPv4)
	c.LocalRouterIPv6 = vp.GetString(LocalRouterIPv6)
	c.EnableBPFClockProbe = vp.GetBool(EnableBPFClockProbe)
	c.EnableIPMasqAgent = vp.GetBool(EnableIPMasqAgent)
	c.EnableEgressGateway = vp.GetBool(EnableEgressGateway) || vp.GetBool(EnableIPv4EgressGateway)
	c.EnableEnvoyConfig = vp.GetBool(EnableEnvoyConfig)
	c.AgentHealthRequireK8sConnectivity = vp.GetBool(AgentHealthRequireK8sConnectivity)
	c.InstallIptRules = vp.GetBool(InstallIptRules)
	c.MonitorAggregation = vp.GetString(MonitorAggregationName)
	c.MonitorAggregationInterval = vp.GetDuration(MonitorAggregationInterval)
	c.MTU = vp.GetInt(MTUName)
	c.PreAllocateMaps = vp.GetBool(PreAllocateMapsName)
	c.ProcFs = vp.GetString(ProcFs)
	c.RestoreState = vp.GetBool(Restore)
	c.RouteMetric = vp.GetInt(RouteMetric)
	c.RunDir = vp.GetString(StateDir)
	c.ExternalEnvoyProxy = vp.GetBool(ExternalEnvoyProxy)
	c.SocketPath = vp.GetString(SocketPath)
	c.TracePayloadlen = vp.GetInt(TracePayloadlen)
	c.TracePayloadlenOverlay = vp.GetInt(TracePayloadlenOverlay)
	c.Version = vp.GetString(Version)
	c.PolicyTriggerInterval = vp.GetDuration(PolicyTriggerInterval)
	c.CTMapEntriesTimeoutTCP = vp.GetDuration(CTMapEntriesTimeoutTCPName)
	c.CTMapEntriesTimeoutAny = vp.GetDuration(CTMapEntriesTimeoutAnyName)
	c.CTMapEntriesTimeoutSVCTCP = vp.GetDuration(CTMapEntriesTimeoutSVCTCPName)
	c.CTMapEntriesTimeoutSVCTCPGrace = vp.GetDuration(CTMapEntriesTimeoutSVCTCPGraceName)
	c.CTMapEntriesTimeoutSVCAny = vp.GetDuration(CTMapEntriesTimeoutSVCAnyName)
	c.CTMapEntriesTimeoutSYN = vp.GetDuration(CTMapEntriesTimeoutSYNName)
	c.CTMapEntriesTimeoutFIN = vp.GetDuration(CTMapEntriesTimeoutFINName)
	c.PolicyAuditMode = vp.GetBool(PolicyAuditModeArg)
	c.PolicyAccounting = vp.GetBool(PolicyAccountingArg)
	c.EnableIPv4FragmentsTracking = vp.GetBool(EnableIPv4FragmentsTrackingName)
	c.EnableIPv6FragmentsTracking = vp.GetBool(EnableIPv6FragmentsTrackingName)
	c.FragmentsMapEntries = vp.GetInt(FragmentsMapEntriesName)
	c.LoadBalancerRSSv4CIDR = vp.GetString(LoadBalancerRSSv4CIDR)
	c.LoadBalancerRSSv6CIDR = vp.GetString(LoadBalancerRSSv6CIDR)
	c.LoadBalancerIPIPSockMark = vp.GetBool(LoadBalancerIPIPSockMark)
	c.InstallNoConntrackIptRules = vp.GetBool(InstallNoConntrackIptRules)
	c.ContainerIPLocalReservedPorts = vp.GetString(ContainerIPLocalReservedPorts)
	c.BGPSecretsNamespace = vp.GetString(BGPSecretsNamespace)
	c.EnableNat46X64Gateway = vp.GetBool(EnableNat46X64Gateway)
	c.EnableRemoteNodeMasquerade = vp.GetBool(EnableRemoteNodeMasquerade)
	c.EnableIPv4Masquerade = vp.GetBool(EnableIPv4Masquerade) && c.EnableIPv4
	c.EnableIPv6Masquerade = vp.GetBool(EnableIPv6Masquerade) && c.EnableIPv6
	c.EnableBPFMasquerade = vp.GetBool(EnableBPFMasquerade)
	c.EnableMasqueradeRouteSource = vp.GetBool(EnableMasqueradeRouteSource)
	c.EnablePMTUDiscovery = vp.GetBool(EnablePMTUDiscovery)
	c.IPv6NAT46x64CIDR = defaults.IPv6NAT46x64CIDR
	c.IPAMCiliumNodeUpdateRate = vp.GetDuration(IPAMCiliumNodeUpdateRate)
	c.BPFDistributedLRU = vp.GetBool(BPFDistributedLRU)
	c.BPFEventsDropEnabled = vp.GetBool(BPFEventsDropEnabled)
	c.BPFEventsPolicyVerdictEnabled = vp.GetBool(BPFEventsPolicyVerdictEnabled)
	c.BPFEventsTraceEnabled = vp.GetBool(BPFEventsTraceEnabled)
	c.BPFConntrackAccounting = vp.GetBool(BPFConntrackAccounting)
	c.BootIDFile = vp.GetString(BootIDFilename)
	c.EnableExtendedIPProtocols = vp.GetBool(EnableExtendedIPProtocols)
	c.IPTracingOptionType = vp.GetUint(IPTracingOptionType)

	c.ServiceNoBackendResponse = vp.GetString(ServiceNoBackendResponse)
	switch c.ServiceNoBackendResponse {
	case ServiceNoBackendResponseReject, ServiceNoBackendResponseDrop:
	case "":
		c.ServiceNoBackendResponse = defaults.ServiceNoBackendResponse
	default:
		logging.Fatal(logger, "Invalid value for --%s: %s (must be 'reject' or 'drop')", ServiceNoBackendResponse, c.ServiceNoBackendResponse)
	}

	c.populateLoadBalancerSettings(logger, vp)
	c.PolicyDenyResponse = vp.GetString(PolicyDenyResponse)
	switch c.PolicyDenyResponse {
	case PolicyDenyResponseIcmp, PolicyDenyResponseNone:
	case "":
		c.PolicyDenyResponse = defaults.PolicyDenyResponse
	default:
		logging.Fatal(logger, "Invalid value for --%s: %s (must be 'icmp' or 'none')", PolicyDenyResponse, c.PolicyDenyResponse)
	}
	c.EgressMultiHomeIPRuleCompat = vp.GetBool(EgressMultiHomeIPRuleCompat)
	c.InstallUplinkRoutesForDelegatedIPAM = vp.GetBool(InstallUplinkRoutesForDelegatedIPAM)

	vlanBPFBypassIDs := vp.GetStringSlice(VLANBPFBypass)
	c.VLANBPFBypass = make([]int, 0, len(vlanBPFBypassIDs))
	for _, vlanIDStr := range vlanBPFBypassIDs {
		vlanID, err := strconv.Atoi(vlanIDStr)
		if err != nil {
			logging.Fatal(logger, fmt.Sprintf("Cannot parse vlan ID integer from --%s option", VLANBPFBypass), logfields.Error, err)
		}
		c.VLANBPFBypass = append(c.VLANBPFBypass, vlanID)
	}

	c.DisableExternalIPMitigation = vp.GetBool(DisableExternalIPMitigation)

	tcFilterPrio := vp.GetUint32(TCFilterPriority)
	if tcFilterPrio > math.MaxUint16 {
		logging.Fatal(logger, fmt.Sprintf("%s cannot be higher than %d", TCFilterPriority, math.MaxUint16))
	}
	c.TCFilterPriority = uint16(tcFilterPrio)

	c.RoutingMode = vp.GetString(RoutingMode)

	if vp.IsSet(AddressScopeMax) {
		c.AddressScopeMax, err = ip.ParseScope(vp.GetString(AddressScopeMax))
		if err != nil {
			logging.Fatal(logger, fmt.Sprintf("Cannot parse scope integer from --%s option", AddressScopeMax), logfields.Error, err)
		}
	} else {
		c.AddressScopeMax = defaults.AddressScopeMax
	}

	if c.EnableNat46X64Gateway || c.NodePortNat46X64 {
		if !c.EnableIPv4 || !c.EnableIPv6 {
			logging.Fatal(logger, fmt.Sprintf("%s requires both --%s and --%s enabled", EnableNat46X64Gateway, EnableIPv4Name, EnableIPv6Name))
		}
	}

	encryptionStrictModeEnabled := vp.GetBool(EnableEncryptionStrictMode)
	if encryptionStrictModeEnabled {
		if c.EnableIPv6 {
			logger.Info("WireGuard encryption strict mode only supports IPv4. IPv6 traffic is not protected and can be leaked.")
		}

		strictCIDR := vp.GetString(EncryptionStrictModeCIDR)
		c.EncryptionStrictModeCIDR, err = netip.ParsePrefix(strictCIDR)
		if err != nil {
			logging.Fatal(logger, fmt.Sprintf("Cannot parse CIDR %s from --%s option", strictCIDR, EncryptionStrictModeCIDR), logfields.Error, err)
		}

		if !c.EncryptionStrictModeCIDR.Addr().Is4() {
			logging.Fatal(logger, fmt.Sprintf("%s must be an IPv4 CIDR", EncryptionStrictModeCIDR))
		}

		c.EncryptionStrictModeAllowRemoteNodeIdentities = vp.GetBool(EncryptionStrictModeAllowRemoteNodeIdentities)
		c.EnableEncryptionStrictMode = encryptionStrictModeEnabled
	}

	ipv4NativeRoutingCIDR := vp.GetString(IPv4NativeRoutingCIDR)

	if ipv4NativeRoutingCIDR != "" {
		c.IPv4NativeRoutingCIDR, err = cidr.ParseCIDR(ipv4NativeRoutingCIDR)
		if err != nil {
			logging.Fatal(logger, fmt.Sprintf("Unable to parse CIDR '%s'", ipv4NativeRoutingCIDR), logfields.Error, err)
		}

		if len(c.IPv4NativeRoutingCIDR.IP) != net.IPv4len {
			logging.Fatal(logger, fmt.Sprintf("%s must be an IPv4 CIDR", IPv4NativeRoutingCIDR))
		}
	}

	ipv6NativeRoutingCIDR := vp.GetString(IPv6NativeRoutingCIDR)

	if ipv6NativeRoutingCIDR != "" {
		c.IPv6NativeRoutingCIDR, err = cidr.ParseCIDR(ipv6NativeRoutingCIDR)
		if err != nil {
			logging.Fatal(logger, fmt.Sprintf("Unable to parse CIDR '%s'", ipv6NativeRoutingCIDR), logfields.Error, err)
		}

		if len(c.IPv6NativeRoutingCIDR.IP) != net.IPv6len {
			logging.Fatal(logger, fmt.Sprintf("%s must be an IPv6 CIDR", IPv6NativeRoutingCIDR))
		}
	}

	if c.DirectRoutingSkipUnreachable && !c.EnableAutoDirectRouting {
		logging.Fatal(logger, fmt.Sprintf("Flag %s cannot be enabled when %s is not enabled. As if %s is then enabled, it may lead to unexpected behaviour causing network connectivity issues.", DirectRoutingSkipUnreachableName, EnableAutoDirectRoutingName, EnableAutoDirectRoutingName))
	}

	if err := c.calculateBPFMapSizes(logger, vp); err != nil {
		logging.Fatal(logger, err.Error())
	}

	c.ClockSource = ClockSourceKtime
	c.EnableIdentityMark = vp.GetBool(EnableIdentityMark)

	// toFQDNs options
	c.DNSPolicyUnloadOnShutdown = vp.GetBool(DNSPolicyUnloadOnShutdown)
	c.FQDNRegexCompileLRUSize = vp.GetUint(FQDNRegexCompileLRUSize)
	c.ToFQDNsMaxIPsPerHost = vp.GetInt(ToFQDNsMaxIPsPerHost)
	if maxZombies := vp.GetInt(ToFQDNsMaxDeferredConnectionDeletes); maxZombies >= 0 {
		c.ToFQDNsMaxDeferredConnectionDeletes = vp.GetInt(ToFQDNsMaxDeferredConnectionDeletes)
	} else {
		logging.Fatal(logger, fmt.Sprintf("%s must be positive, or 0 to disable deferred connection deletion",
			ToFQDNsMaxDeferredConnectionDeletes))
	}
	switch {
	case vp.IsSet(ToFQDNsMinTTL): // set by user
		c.ToFQDNsMinTTL = vp.GetInt(ToFQDNsMinTTL)
	default:
		c.ToFQDNsMinTTL = defaults.ToFQDNsMinTTL
	}
	c.ToFQDNsProxyPort = vp.GetInt(ToFQDNsProxyPort)
	c.ToFQDNsPreCache = vp.GetString(ToFQDNsPreCache)
	c.ToFQDNsIdleConnectionGracePeriod = vp.GetDuration(ToFQDNsIdleConnectionGracePeriod)
	c.FQDNProxyResponseMaxDelay = vp.GetDuration(FQDNProxyResponseMaxDelay)
	c.DNSProxyConcurrencyLimit = vp.GetInt(DNSProxyConcurrencyLimit)
	c.DNSProxyEnableTransparentMode = vp.GetBool(DNSProxyEnableTransparentMode)
	c.DNSProxyLockCount = vp.GetInt(DNSProxyLockCount)
	c.DNSProxyLockTimeout = vp.GetDuration(DNSProxyLockTimeout)
	c.DNSProxySocketLingerTimeout = vp.GetInt(DNSProxySocketLingerTimeout)
	c.FQDNRejectResponse = vp.GetString(FQDNRejectResponseCode)

	// Convert IP strings into net.IPNet types
	subnets, invalid := ip.ParseCIDRs(vp.GetStringSlice(IPv4PodSubnets))
	if len(invalid) > 0 {
		logger.Warn("IPv4PodSubnets parameter can not be parsed.",
			logfields.Subnets, invalid,
		)
	}
	c.IPv4PodSubnets = subnets

	subnets, invalid = ip.ParseCIDRs(vp.GetStringSlice(IPv6PodSubnets))
	if len(invalid) > 0 {
		logger.Warn("IPv6PodSubnets parameter can not be parsed.",
			logfields.Subnets, invalid,
		)
	}
	c.IPv6PodSubnets = subnets

	monitorAggregationFlags := vp.GetStringSlice(MonitorAggregationFlags)
	var ctMonitorReportFlags uint16
	for i := range monitorAggregationFlags {
		value := strings.ToLower(monitorAggregationFlags[i])
		flag, exists := TCPFlags[value]
		if !exists {
			logging.Fatal(logger, fmt.Sprintf("Unable to parse TCP flag %q for %s!", value, MonitorAggregationFlags))
		}
		ctMonitorReportFlags |= flag
	}
	c.MonitorAggregationFlags = ctMonitorReportFlags

	// Map options
	if m := command.GetStringMapString(vp, FixedIdentityMapping); err != nil {
		logging.Fatal(logger, fmt.Sprintf("unable to parse %s: %s", FixedIdentityMapping, err))
	} else if len(m) != 0 {
		c.FixedIdentityMapping = m
	}

	if m := command.GetStringMapString(vp, FixedZoneMapping); err != nil {
		logging.Fatal(logger, fmt.Sprintf("unable to parse %s: %s", FixedZoneMapping, err))
	} else if len(m) != 0 {
		forward := make(map[string]uint8, len(m))
		reverse := make(map[uint8]string, len(m))
		for k, v := range m {
			bigN, _ := strconv.Atoi(v)
			n := uint8(bigN)
			if oldKey, ok := reverse[n]; ok && oldKey != k {
				logging.Fatal(logger, fmt.Sprintf("duplicate numeric ID entry for %s: %q and %q map to the same value %d", FixedZoneMapping, oldKey, k, n))
			}
			if oldN, ok := forward[k]; ok && oldN != n {
				logging.Fatal(logger, fmt.Sprintf("duplicate zone name entry for %s: %d and %d map to different values %s", FixedZoneMapping, oldN, n, k))
			}
			forward[k] = n
			reverse[n] = k
		}
		c.FixedZoneMapping = forward
		c.ReverseFixedZoneMapping = reverse
	}

	c.ConntrackGCInterval = vp.GetDuration(ConntrackGCInterval)
	c.ConntrackGCMaxInterval = vp.GetDuration(ConntrackGCMaxInterval)

	bpfEventsDefaultRateLimit := vp.GetUint32(BPFEventsDefaultRateLimit)
	bpfEventsDefaultBurstLimit := vp.GetUint32(BPFEventsDefaultBurstLimit)
	switch {
	case bpfEventsDefaultRateLimit > 0 && bpfEventsDefaultBurstLimit == 0:
		logging.Fatal(logger, "invalid BPF events default config: burst limit must also be specified when rate limit is provided")
	case bpfEventsDefaultRateLimit == 0 && bpfEventsDefaultBurstLimit > 0:
		logging.Fatal(logger, "invalid BPF events default config: rate limit must also be specified when burst limit is provided")
	default:
		c.BPFEventsDefaultRateLimit = vp.GetUint32(BPFEventsDefaultRateLimit)
		c.BPFEventsDefaultBurstLimit = vp.GetUint32(BPFEventsDefaultBurstLimit)
	}

	c.bpfMapEventConfigs = make(BPFEventBufferConfigs)
	parseBPFMapEventConfigs(c.bpfMapEventConfigs, defaults.BPFEventBufferConfigs)
	if m, err := command.GetStringMapStringE(vp, BPFMapEventBuffers); err != nil {
		logging.Fatal(logger, fmt.Sprintf("unable to parse %s: %s", BPFMapEventBuffers, err))
	} else {
		parseBPFMapEventConfigs(c.bpfMapEventConfigs, m)
	}

	if err := c.parseExcludedLocalAddresses(vp.GetStringSlice(ExcludeLocalAddress)); err != nil {
		logging.Fatal(logger, "Unable to parse excluded local addresses", logfields.Error, err)
	}

	// Ensure CiliumEndpointSlice is enabled only if CiliumEndpointCRD is enabled too.
	c.EnableCiliumEndpointSlice = vp.GetBool(EnableCiliumEndpointSlice)
	if c.EnableCiliumEndpointSlice && c.DisableCiliumEndpointCRD {
		logging.Fatal(logger, fmt.Sprintf("Running Cilium with %s=%t requires %s set to false to enable CiliumEndpoint CRDs.",
			EnableCiliumEndpointSlice, c.EnableCiliumEndpointSlice, DisableCiliumEndpointCRDName))
	}

	// To support K8s NetworkPolicy
	c.EnableK8sNetworkPolicy = vp.GetBool(EnableK8sNetworkPolicy)
	c.PolicyCIDRMatchMode = vp.GetStringSlice(PolicyCIDRMatchMode)
	c.EnableNodeSelectorLabels = vp.GetBool(EnableNodeSelectorLabels)
	c.NodeLabels = vp.GetStringSlice(NodeLabels)

	c.EnableCiliumNetworkPolicy = vp.GetBool(EnableCiliumNetworkPolicy)
	c.EnableCiliumClusterwideNetworkPolicy = vp.GetBool(EnableCiliumClusterwideNetworkPolicy)

	c.IdentityAllocationMode = vp.GetString(IdentityAllocationMode)
	switch c.IdentityAllocationMode {
	// This is here for tests. Some call Populate without the normal init
	case "":
		c.IdentityAllocationMode = IdentityAllocationModeKVstore
	case IdentityAllocationModeKVstore, IdentityAllocationModeCRD, IdentityAllocationModeDoubleWriteReadKVstore, IdentityAllocationModeDoubleWriteReadCRD:
		// c.IdentityAllocationMode is set above
	default:
		logging.Fatal(logger, fmt.Sprintf("Invalid identity allocation mode %q. It must be one of %s, %s or %s / %s", c.IdentityAllocationMode, IdentityAllocationModeKVstore, IdentityAllocationModeCRD, IdentityAllocationModeDoubleWriteReadKVstore, IdentityAllocationModeDoubleWriteReadCRD))
	}

	theKVStore := vp.GetString(KVStore)
	if theKVStore == "" {
		if c.IdentityAllocationMode != IdentityAllocationModeCRD {
			logger.Warn(fmt.Sprintf("Running Cilium with %q=%q requires identity allocation via CRDs. Changing %s to %q", KVStore, theKVStore, IdentityAllocationMode, IdentityAllocationModeCRD))
			c.IdentityAllocationMode = IdentityAllocationModeCRD
		}
		if c.DisableCiliumEndpointCRD && NetworkPolicyEnabled(c) {
			logger.Warn(fmt.Sprintf("Running Cilium with %q=%q requires endpoint CRDs when network policy enforcement system is enabled. Changing %s to %t", KVStore, theKVStore, DisableCiliumEndpointCRDName, false))
			c.DisableCiliumEndpointCRD = false
		}
	}

	switch c.IPAM {
	case ipamOption.IPAMKubernetes, ipamOption.IPAMClusterPool:
		if c.EnableIPv4 {
			c.K8sRequireIPv4PodCIDR = true
		}

		if c.EnableIPv6 {
			c.K8sRequireIPv6PodCIDR = true
		}
	}
	if m, err := command.GetStringMapStringE(vp, IPAMMultiPoolPreAllocation); err != nil {
		logging.Fatal(logger, fmt.Sprintf("unable to parse %s: %s", IPAMMultiPoolPreAllocation, err))
	} else {
		c.IPAMMultiPoolPreAllocation = m
	}
	if len(c.IPAMMultiPoolPreAllocation) == 0 {
		// Default to the same value as IPAMDefaultIPPool
		c.IPAMMultiPoolPreAllocation = map[string]string{c.IPAMDefaultIPPool: "8"}
	}

	// Hidden options
	c.ConfigFile = vp.GetString(ConfigFile)
	c.HTTP403Message = vp.GetString(HTTP403Message)
	c.K8sNamespace = vp.GetString(K8sNamespaceName)
	c.AgentNotReadyNodeTaintKey = vp.GetString(AgentNotReadyNodeTaintKeyName)
	c.MaxControllerInterval = vp.GetUint(MaxCtrlIntervalName)
	c.EndpointQueueSize = sanitizeIntParam(logger, vp, EndpointQueueSize, defaults.EndpointQueueSize)
	c.EnableICMPRules = vp.GetBool(EnableICMPRules)
	c.BypassIPAvailabilityUponRestore = vp.GetBool(BypassIPAvailabilityUponRestore)

	// VTEP integration enable option
	c.EnableVTEP = vp.GetBool(EnableVTEP)

	// Enable BGP control plane features
	c.EnableBGPControlPlane = vp.GetBool(EnableBGPControlPlane)

	// Enable BGP control plane status reporting
	c.EnableBGPControlPlaneStatusReport = vp.GetBool(EnableBGPControlPlaneStatusReport)

	// BGP router-id allocation mode
	c.BGPRouterIDAllocationMode = vp.GetString(BGPRouterIDAllocationMode)
	c.BGPRouterIDAllocationIPPool = vp.GetString(BGPRouterIDAllocationIPPool)

	// Support failure-mode for policy map overflow
	c.EnableEndpointLockdownOnPolicyOverflow = vp.GetBool(EnableEndpointLockdownOnPolicyOverflow)

	// Parse node label patterns
	nodeLabelPatterns := vp.GetStringSlice(ExcludeNodeLabelPatterns)
	for _, pattern := range nodeLabelPatterns {
		r, err := regexp.Compile(pattern)
		if err != nil {
			logger.Error(fmt.Sprintf("Unable to compile exclude node label regex pattern %s", pattern), logfields.Error, err)
			continue
		}
		c.ExcludeNodeLabelPatterns = append(c.ExcludeNodeLabelPatterns, r)
	}

	if theKVStore != "" {
		c.IdentityRestoreGracePeriod = defaults.IdentityRestoreGracePeriodKvstore
	}

	c.EnableSourceIPVerification = vp.GetBool(EnableSourceIPVerification)

	// Allow the range [0.0, 1.0].
	connectivityFreqRatio := vp.GetFloat64(ConnectivityProbeFrequencyRatio)
	if 0.0 <= connectivityFreqRatio && connectivityFreqRatio <= 1.0 {
		c.ConnectivityProbeFrequencyRatio = connectivityFreqRatio
	} else {
		logger.Warn(
			"specified connectivity probe frequency ratio must be in the range [0.0, 1.0], using default",
			logfields.Ratio, connectivityFreqRatio,
		)
		c.ConnectivityProbeFrequencyRatio = defaults.ConnectivityProbeFrequencyRatio
	}
}

func (c *DaemonConfig) populateLoadBalancerSettings(logger *slog.Logger, vp *viper.Viper) {
	c.NodePortAcceleration = vp.GetString(LoadBalancerAcceleration)
	// If old settings were explicitly set by the user, then have them
	// override the new ones in order to not break existing setups.
	if vp.IsSet(NodePortAcceleration) {
		prior := c.NodePortAcceleration
		c.NodePortAcceleration = vp.GetString(NodePortAcceleration)
		if vp.IsSet(LoadBalancerAcceleration) && prior != c.NodePortAcceleration {
			logging.Fatal(logger, fmt.Sprintf("Both --%s and --%s were set. Only use --%s instead.",
				LoadBalancerAcceleration, NodePortAcceleration, LoadBalancerAcceleration))
		}
	}
}

func (c *DaemonConfig) checkMapSizeLimits() error {
	if c.AuthMapEntries < AuthMapEntriesMin {
		return fmt.Errorf("specified AuthMap max entries %d must be greater or equal to %d", c.AuthMapEntries, AuthMapEntriesMin)
	}
	if c.AuthMapEntries > AuthMapEntriesMax {
		return fmt.Errorf("specified AuthMap max entries %d must not exceed maximum %d", c.AuthMapEntries, AuthMapEntriesMax)
	}

	if c.CTMapEntriesGlobalTCP < LimitTableMin || c.CTMapEntriesGlobalAny < LimitTableMin {
		return fmt.Errorf("specified CT tables values %d/%d must be greater or equal to %d",
			c.CTMapEntriesGlobalTCP, c.CTMapEntriesGlobalAny, LimitTableMin)
	}
	if c.CTMapEntriesGlobalTCP > LimitTableMax || c.CTMapEntriesGlobalAny > LimitTableMax {
		return fmt.Errorf("specified CT tables values %d/%d must not exceed maximum %d",
			c.CTMapEntriesGlobalTCP, c.CTMapEntriesGlobalAny, LimitTableMax)
	}

	if c.NATMapEntriesGlobal < LimitTableMin {
		return fmt.Errorf("specified NAT table size %d must be greater or equal to %d",
			c.NATMapEntriesGlobal, LimitTableMin)
	}
	if c.NATMapEntriesGlobal > LimitTableMax {
		return fmt.Errorf("specified NAT tables size %d must not exceed maximum %d",
			c.NATMapEntriesGlobal, LimitTableMax)
	}
	if c.NATMapEntriesGlobal > c.CTMapEntriesGlobalTCP+c.CTMapEntriesGlobalAny {
		if c.NATMapEntriesGlobal == NATMapEntriesGlobalDefault {
			// Auto-size for the case where CT table size was adapted but NAT still on default
			c.NATMapEntriesGlobal = int((c.CTMapEntriesGlobalTCP + c.CTMapEntriesGlobalAny) * 2 / 3)
		} else {
			return fmt.Errorf("specified NAT tables size %d must not exceed maximum CT table size %d",
				c.NATMapEntriesGlobal, c.CTMapEntriesGlobalTCP+c.CTMapEntriesGlobalAny)
		}
	}

	if c.FragmentsMapEntries < FragmentsMapMin {
		return fmt.Errorf("specified max entries %d for fragment-tracking map must be greater or equal to %d",
			c.FragmentsMapEntries, FragmentsMapMin)
	}
	if c.FragmentsMapEntries > FragmentsMapMax {
		return fmt.Errorf("specified max entries %d for fragment-tracking map must not exceed maximum %d",
			c.FragmentsMapEntries, FragmentsMapMax)
	}

	return nil
}

func (c *DaemonConfig) checkIPv4NativeRoutingCIDR() error {
	if c.IPv4NativeRoutingCIDR != nil {
		return nil
	}
	if !c.EnableIPv4 || !c.EnableIPv4Masquerade {
		return nil
	}
	if c.EnableIPMasqAgent {
		return nil
	}
	if c.TunnelingEnabled() {
		return nil
	}
	if c.IPAMMode() == ipamOption.IPAMENI || c.IPAMMode() == ipamOption.IPAMAlibabaCloud {
		return nil
	}

	return fmt.Errorf(
		"native routing cidr must be configured with option --%s "+
			"in combination with --%s=true --%s=true --%s=false --%s=%s --%s=%s",
		IPv4NativeRoutingCIDR,
		EnableIPv4Name, EnableIPv4Masquerade,
		EnableIPMasqAgent,
		RoutingMode, RoutingModeNative,
		IPAM, c.IPAMMode())
}

func (c *DaemonConfig) checkIPv6NativeRoutingCIDR() error {
	if c.IPv6NativeRoutingCIDR != nil {
		return nil
	}
	if !c.EnableIPv6 || !c.EnableIPv6Masquerade {
		return nil
	}
	if c.EnableIPMasqAgent {
		return nil
	}
	if c.TunnelingEnabled() {
		return nil
	}
	return fmt.Errorf(
		"native routing cidr must be configured with option --%s "+
			"in combination with --%s=true --%s=true --%s=false --%s=%s",
		IPv6NativeRoutingCIDR,
		EnableIPv6Name, EnableIPv6Masquerade,
		EnableIPMasqAgent,
		RoutingMode, RoutingModeNative)
}

func (c *DaemonConfig) checkIPAMDelegatedPlugin() error {
	if c.IPAM == ipamOption.IPAMDelegatedPlugin {
		// When using IPAM delegated plugin, IP addresses are allocated by the CNI binary,
		// not the daemon. Therefore, features which require the daemon to allocate IPs for itself
		// must be disabled.
		if c.EnableIPv4 && c.LocalRouterIPv4 == "" {
			return fmt.Errorf("--%s must be provided when IPv4 is enabled with --%s=%s", LocalRouterIPv4, IPAM, ipamOption.IPAMDelegatedPlugin)
		}
		if c.EnableIPv6 && c.LocalRouterIPv6 == "" {
			return fmt.Errorf("--%s must be provided when IPv6 is enabled with --%s=%s", LocalRouterIPv6, IPAM, ipamOption.IPAMDelegatedPlugin)
		}
		if c.EnableEndpointHealthChecking {
			return fmt.Errorf("--%s must be disabled with --%s=%s", EnableEndpointHealthChecking, IPAM, ipamOption.IPAMDelegatedPlugin)
		}
		// envoy config (Ingress, Gateway API, ...) require cilium-agent to create an IP address
		// specifically for differentiating envoy traffic, which is not possible
		// with delegated IPAM.
		if c.EnableEnvoyConfig {
			return fmt.Errorf("--%s must be disabled with --%s=%s", EnableEnvoyConfig, IPAM, ipamOption.IPAMDelegatedPlugin)
		}
	}
	return nil
}

func (c *DaemonConfig) calculateBPFMapSizes(logger *slog.Logger, vp *viper.Viper) error {
	// BPF map size options
	// Any map size explicitly set via option will override the dynamic
	// sizing.
	c.AuthMapEntries = vp.GetInt(AuthMapEntriesName)
	c.CTMapEntriesGlobalTCP = vp.GetInt(CTMapEntriesGlobalTCPName)
	c.CTMapEntriesGlobalAny = vp.GetInt(CTMapEntriesGlobalAnyName)
	c.NATMapEntriesGlobal = vp.GetInt(NATMapEntriesGlobalName)
	c.NeighMapEntriesGlobal = vp.GetInt(NeighMapEntriesGlobalName)
	c.PolicyMapFullReconciliationInterval = vp.GetDuration(PolicyMapFullReconciliationIntervalName)

	// Don't attempt dynamic sizing if any of the sizeof members was not
	// populated by the daemon (or any other caller).
	if c.SizeofCTElement == 0 ||
		c.SizeofNATElement == 0 ||
		c.SizeofNeighElement == 0 ||
		c.SizeofSockRevElement == 0 {
		return nil
	}

	// Allow the range (0.0, 1.0] because the dynamic size will anyway be
	// clamped to the table limits. Thus, a ratio of e.g. 0.98 will not lead
	// to 98% of the total memory being allocated for BPF maps.
	dynamicSizeRatio := vp.GetFloat64(MapEntriesGlobalDynamicSizeRatioName)
	if 0.0 < dynamicSizeRatio && dynamicSizeRatio <= 1.0 {
		vms, err := memory.Get()
		if err != nil || vms == nil {
			logging.Fatal(logger, "Failed to get system memory", logfields.Error, err)
		}
		c.BPFMapsDynamicSizeRatio = dynamicSizeRatio
		c.calculateDynamicBPFMapSizes(logger, vp, vms.Total, dynamicSizeRatio)
	} else if c.BPFDistributedLRU {
		return fmt.Errorf("distributed LRU is only valid with a specified dynamic map size ratio")
	} else if dynamicSizeRatio < 0.0 {
		return fmt.Errorf("specified dynamic map size ratio %f must be > 0.0", dynamicSizeRatio)
	} else if dynamicSizeRatio > 1.0 {
		return fmt.Errorf("specified dynamic map size ratio %f must be ≤ 1.0", dynamicSizeRatio)
	}
	return nil
}

// SetMapElementSizes sets the BPF map element sizes (key + value) used for
// dynamic BPF map size calculations in calculateDynamicBPFMapSizes.
func (c *DaemonConfig) SetMapElementSizes(
	sizeofCTElement,
	sizeofNATElement,
	sizeofNeighElement,
	sizeofSockRevElement int) {

	c.SizeofCTElement = sizeofCTElement
	c.SizeofNATElement = sizeofNATElement
	c.SizeofNeighElement = sizeofNeighElement
	c.SizeofSockRevElement = sizeofSockRevElement
}

func (c *DaemonConfig) GetDynamicSizeCalculator(logger *slog.Logger) func(def int, min int, max int) int {
	vms, err := memory.Get()
	if err != nil || vms == nil {
		logging.Fatal(logger, "Failed to get system memory", logfields.Error, err)
	}

	return c.getDynamicSizeCalculator(logger, c.BPFMapsDynamicSizeRatio, vms.Total)
}

func (c *DaemonConfig) getDynamicSizeCalculator(logger *slog.Logger, dynamicSizeRatio float64, totalMemory uint64) func(def int, min int, max int) int {
	if 0.0 >= dynamicSizeRatio || dynamicSizeRatio > 1.0 {
		return func(def int, min int, max int) int { return def }
	}

	possibleCPUs := 1
	// Heuristic:
	// Distribute relative to map default entries among the different maps.
	// Cap each map size by the maximum. Map size provided by the user will
	// override the calculated value and also the max. There will be a check
	// for maximum size later on in DaemonConfig.Validate()
	//
	// Calculation examples:
	//
	// Memory   CT TCP  CT Any      NAT
	//
	//  512MB    33140   16570    33140
	//    1GB    66280   33140    66280
	//    4GB   265121  132560   265121
	//   16GB  1060485  530242  1060485

	memoryAvailableForMaps := int(float64(totalMemory) * dynamicSizeRatio)
	logger.Info(fmt.Sprintf("Memory available for map entries (%.3f%% of %dB): %dB", dynamicSizeRatio*100, totalMemory, memoryAvailableForMaps))
	totalMapMemoryDefault := CTMapEntriesGlobalTCPDefault*c.SizeofCTElement +
		CTMapEntriesGlobalAnyDefault*c.SizeofCTElement +
		NATMapEntriesGlobalDefault*c.SizeofNATElement +
		// Neigh table has the same number of entries as NAT Map has.
		NATMapEntriesGlobalDefault*c.SizeofNeighElement +
		SockRevNATMapEntriesDefault*c.SizeofSockRevElement
	logger.Debug(fmt.Sprintf("Total memory for default map entdries: %d", totalMapMemoryDefault))

	// In case of distributed LRU, we need to round up to the number of possible CPUs
	// since this is also what the kernel does internally, see htab_map_alloc()'s:
	//
	//   htab->map.max_entries = roundup(attr->max_entries,
	//				     num_possible_cpus());
	//
	// Thus, if we would not round up from agent side, then Cilium would constantly
	// try to replace maps due to property mismatch!
	if c.BPFDistributedLRU {
		cpus, err := ebpf.PossibleCPU()
		if err != nil {
			logging.Fatal(logger, "Failed to get number of possible CPUs needed for the distributed LRU")
		}
		possibleCPUs = cpus
	}
	return func(entriesDefault, min, max int) int {
		entries := (entriesDefault * memoryAvailableForMaps) / totalMapMemoryDefault
		entries = util.RoundUp(entries, possibleCPUs)
		if entries < min {
			entries = util.RoundUp(min, possibleCPUs)
		} else if entries > max {
			entries = util.RoundDown(max, possibleCPUs)
		}
		return entries
	}
}

func (c *DaemonConfig) calculateDynamicBPFMapSizes(logger *slog.Logger, vp *viper.Viper, totalMemory uint64, dynamicSizeRatio float64) {
	getEntries := c.getDynamicSizeCalculator(logger, dynamicSizeRatio, totalMemory)

	// If value for a particular map was explicitly set by an
	// option, disable dynamic sizing for this map and use the
	// provided size.
	if !vp.IsSet(CTMapEntriesGlobalTCPName) {
		c.CTMapEntriesGlobalTCP =
			getEntries(CTMapEntriesGlobalTCPDefault, LimitTableAutoGlobalTCPMin, LimitTableMax)
		logger.Info(fmt.Sprintf("option %s set by dynamic sizing to %v",
			CTMapEntriesGlobalTCPName, c.CTMapEntriesGlobalTCP))
	} else {
		logger.Debug(fmt.Sprintf("option %s set by user to %v", CTMapEntriesGlobalTCPName, c.CTMapEntriesGlobalTCP))
	}
	if !vp.IsSet(CTMapEntriesGlobalAnyName) {
		c.CTMapEntriesGlobalAny =
			getEntries(CTMapEntriesGlobalAnyDefault, LimitTableAutoGlobalAnyMin, LimitTableMax)
		logger.Info(fmt.Sprintf("option %s set by dynamic sizing to %v",
			CTMapEntriesGlobalAnyName, c.CTMapEntriesGlobalAny))
	} else {
		logger.Debug(fmt.Sprintf("option %s set by user to %v", CTMapEntriesGlobalAnyName, c.CTMapEntriesGlobalAny))
	}
	if !vp.IsSet(NATMapEntriesGlobalName) {
		c.NATMapEntriesGlobal =
			getEntries(NATMapEntriesGlobalDefault, LimitTableAutoNatGlobalMin, LimitTableMax)
		logger.Info(fmt.Sprintf("option %s set by dynamic sizing to %v",
			NATMapEntriesGlobalName, c.NATMapEntriesGlobal))
		if c.NATMapEntriesGlobal > c.CTMapEntriesGlobalTCP+c.CTMapEntriesGlobalAny {
			// CT table size was specified manually, make sure that the NAT table size
			// does not exceed maximum CT table size. See
			// (*DaemonConfig).checkMapSizeLimits.
			c.NATMapEntriesGlobal = (c.CTMapEntriesGlobalTCP + c.CTMapEntriesGlobalAny) * 2 / 3
			logger.Warn(fmt.Sprintf("option %s would exceed maximum determined by CT table sizes, capping to %v",
				NATMapEntriesGlobalName, c.NATMapEntriesGlobal))
		}
	} else {
		logger.Debug(fmt.Sprintf("option %s set by user to %v", NATMapEntriesGlobalName, c.NATMapEntriesGlobal))
	}
	if !vp.IsSet(NeighMapEntriesGlobalName) {
		// By default we auto-size it to the same value as the NAT map since we
		// need to keep at least as many neigh entries.
		c.NeighMapEntriesGlobal = c.NATMapEntriesGlobal
		logger.Info(fmt.Sprintf("option %s set by dynamic sizing to %v",
			NeighMapEntriesGlobalName, c.NeighMapEntriesGlobal))
	} else {
		logger.Debug(fmt.Sprintf("option %s set by user to %v", NeighMapEntriesGlobalName, c.NeighMapEntriesGlobal))
	}
}

// Validate VTEP integration configuration
func (c *DaemonConfig) validateVTEP(vp *viper.Viper) error {
	vtepCidrMask := vp.GetString(VtepMask)

	mask := net.ParseIP(vtepCidrMask)
	if mask == nil {
		return fmt.Errorf("Invalid VTEP CIDR Mask: %v", vtepCidrMask)
	}
	c.VtepCidrMask = mask

	return nil
}

var backupFileNames []string = []string{
	"agent-runtime-config.json",
	"agent-runtime-config-1.json",
	"agent-runtime-config-2.json",
}

// StoreInFile stores the configuration in a the given directory under the file
// name 'daemon-config.json'. If this file already exists, it is renamed to
// 'daemon-config-1.json', if 'daemon-config-1.json' also exists,
// 'daemon-config-1.json' is renamed to 'daemon-config-2.json'
// Caller is responsible for blocking concurrent changes.
func (c *DaemonConfig) StoreInFile(logger *slog.Logger, dir string) error {
	backupFiles(logger, dir, backupFileNames)
	f, err := os.Create(backupFileNames[0])
	if err != nil {
		return err
	}
	defer f.Close()
	e := json.NewEncoder(f)
	e.SetIndent("", " ")

	err = e.Encode(c)
	c.shaSum = c.checksum()

	return err
}

func (c *DaemonConfig) checksum() [32]byte {
	// take a shallow copy for summing
	sumConfig := *c
	// Ignore variable parts
	sumConfig.Opts = nil
	sumConfig.EncryptInterface = nil
	cBytes, err := json.Marshal(&sumConfig)
	if err != nil {
		return [32]byte{}
	}
	return sha256.Sum256(cBytes)
}

// ValidateUnchanged checks that invariable parts of the config have not changed since init.
// Caller is responsible for blocking concurrent changes.
func (c *DaemonConfig) ValidateUnchanged() error {
	sum := c.checksum()
	if sum != c.shaSum {
		return c.diffFromFile()
	}
	return nil
}

func (c *DaemonConfig) diffFromFile() error {
	f, err := os.Open(backupFileNames[0])
	if err != nil {
		return err
	}

	fi, err := f.Stat()
	if err != nil {
		return err
	}

	fileBytes := make([]byte, fi.Size())
	count, err := f.Read(fileBytes)
	if err != nil {
		return err
	}
	fileBytes = fileBytes[:count]

	var config DaemonConfig
	err = json.Unmarshal(fileBytes, &config)

	var diff string
	if err != nil {
		diff = fmt.Errorf("unmarshal failed %q: %w", string(fileBytes), err).Error()
	} else {
		// Ignore all unexported fields during Diff.
		// from https://github.com/google/go-cmp/issues/313#issuecomment-1315651560
		opts := cmp.FilterPath(func(p cmp.Path) bool {
			sf, ok := p.Index(-1).(cmp.StructField)
			if !ok {
				return false
			}
			r, _ := utf8.DecodeRuneInString(sf.Name())
			return !unicode.IsUpper(r)
		}, cmp.Ignore())

		diff = cmp.Diff(&config, c, opts,
			cmpopts.IgnoreTypes(&IntOptions{}),
			cmpopts.IgnoreTypes(&OptionLibrary{}),
			cmpopts.IgnoreFields(DaemonConfig{}, "EncryptInterface"))
	}
	return fmt.Errorf("Config differs:\n%s", diff)
}

func (c *DaemonConfig) BGPControlPlaneEnabled() bool {
	return c.EnableBGPControlPlane
}

func (c *DaemonConfig) IsDualStack() bool {
	return c.EnableIPv4 && c.EnableIPv6
}

// IsLocalRouterIP checks if provided IP address matches either LocalRouterIPv4
// or LocalRouterIPv6
func (c *DaemonConfig) IsLocalRouterIP(ip string) bool {
	return ip != "" && (c.LocalRouterIPv4 == ip || c.LocalRouterIPv6 == ip)
}

// StoreViperInFile stores viper's configuration in a the given directory under
// the file name 'viper-config.yaml'. If this file already exists, it is renamed
// to 'viper-config-1.yaml', if 'viper-config-1.yaml' also exists,
// 'viper-config-1.yaml' is renamed to 'viper-config-2.yaml'
func StoreViperInFile(logger *slog.Logger, dir string) error {
	backupFileNames := []string{
		"viper-agent-config.yaml",
		"viper-agent-config-1.yaml",
		"viper-agent-config-2.yaml",
	}
	backupFiles(logger, dir, backupFileNames)
	return viper.WriteConfigAs(backupFileNames[0])
}

func backupFiles(logger *slog.Logger, dir string, backupFilenames []string) {
	for i := len(backupFilenames) - 1; i > 0; i-- {
		newFileName := filepath.Join(dir, backupFilenames[i-1])
		oldestFilename := filepath.Join(dir, backupFilenames[i])
		if _, err := os.Stat(newFileName); os.IsNotExist(err) {
			continue
		}
		err := os.Rename(newFileName, oldestFilename)
		if err != nil {
			logger.Error(
				"Unable to rename configuration files",
				logfields.OldName, oldestFilename,
				logfields.NewName, newFileName,
			)
		}
	}
}

func sanitizeIntParam(logger *slog.Logger, vp *viper.Viper, paramName string, paramDefault int) int {
	intParam := vp.GetInt(paramName)
	if intParam <= 0 {
		if vp.IsSet(paramName) {
			logger.Warn(
				"user-provided parameter had value <= 0 , which is invalid ; setting to default",
				logfields.Param, paramName,
				logfields.Value, paramDefault,
			)
		}
		return paramDefault
	}
	return intParam
}

func validateConfigMapFlag(flag *pflag.Flag, key string, value any) error {
	var err error
	switch t := flag.Value.Type(); t {
	case "bool":
		_, err = cast.ToBoolE(value)
	case "duration":
		_, err = cast.ToDurationE(value)
	case "float32":
		_, err = cast.ToFloat32E(value)
	case "float64":
		_, err = cast.ToFloat64E(value)
	case "int":
		_, err = cast.ToIntE(value)
	case "int8":
		_, err = cast.ToInt8E(value)
	case "int16":
		_, err = cast.ToInt16E(value)
	case "int32":
		_, err = cast.ToInt32E(value)
	case "int64":
		_, err = cast.ToInt64E(value)
	case "map":
		// custom type, see pkg/option/map_options.go
		err = flag.Value.Set(fmt.Sprintf("%s", value))
	case "stringSlice":
		_, err = cast.ToStringSliceE(value)
	case "string":
		_, err = cast.ToStringE(value)
	case "uint":
		_, err = cast.ToUintE(value)
	case "uint8":
		_, err = cast.ToUint8E(value)
	case "uint16":
		_, err = cast.ToUint16E(value)
	case "uint32":
		_, err = cast.ToUint32E(value)
	case "uint64":
		_, err = cast.ToUint64E(value)
	case "stringToString":
		_, err = command.ToStringMapStringE(value)
	default:
		return fmt.Errorf("unable to validate option %s value of type %s", key, t)
	}
	return err
}

// validateConfigMap checks whether the flag exists and validate its value
func validateConfigMap(cmd *cobra.Command, m map[string]any) error {
	flags := cmd.Flags()

	for key, value := range m {
		flag := flags.Lookup(key)
		if flag == nil {
			continue
		}
		err := validateConfigMapFlag(flag, key, value)
		if err != nil {
			return fmt.Errorf("option %s: %w", key, err)
		}
	}
	return nil
}

// InitConfig reads in config file and ENV variables if set.
func InitConfig(logger *slog.Logger, cmd *cobra.Command, programName, configName string, vp *viper.Viper) func() {
	return func() {
		if vp.GetBool("version") {
			fmt.Printf("%s %s\n", programName, version.Version)
			os.Exit(0)
		}

		if vp.GetString(CMDRef) != "" {
			return
		}

		Config.ConfigFile = vp.GetString(ConfigFile) // enable ability to specify config file via flag
		Config.ConfigDir = vp.GetString(ConfigDir)
		vp.SetEnvPrefix("cilium")

		if Config.ConfigDir != "" {
			if _, err := os.Stat(Config.ConfigDir); os.IsNotExist(err) {
				logging.Fatal(logger, fmt.Sprintf("Non-existent configuration directory %s", Config.ConfigDir))
			}

			if m, err := ReadDirConfig(logger, Config.ConfigDir); err != nil {
				logging.Fatal(logger, fmt.Sprintf("Unable to read configuration directory %s", Config.ConfigDir), logfields.Error, err)
			} else {
				// replace deprecated fields with new fields
				ReplaceDeprecatedFields(m)

				// validate the config-map
				if err := validateConfigMap(cmd, m); err != nil {
					logging.Fatal(logger, "Incorrect config-map flag value", logfields.Error, err)
				}

				if err := MergeConfig(vp, m); err != nil {
					logging.Fatal(logger, "Unable to merge configuration", logfields.Error, err)
				}
			}
		}

		if Config.ConfigFile != "" {
			vp.SetConfigFile(Config.ConfigFile)
		} else {
			vp.SetConfigName(configName) // name of config file (without extension)
			vp.AddConfigPath("$HOME")    // adding home directory as first search path
		}

		// We need to check for the debug environment variable or CLI flag before
		// loading the configuration file since on configuration file read failure
		// we will emit a debug log entry.
		if vp.GetBool(DebugArg) {
			logging.SetLogLevelToDebug()
		}

		// If a config file is found, read it in.
		if err := vp.ReadInConfig(); err == nil {
			logger.Info("Using config from file", logfields.Path, vp.ConfigFileUsed())
		} else if Config.ConfigFile != "" {
			logging.Fatal(logger,
				"Error reading config file",
				logfields.Path, vp.ConfigFileUsed(),
				logfields.Error, err,
			)
		} else {
			logger.Debug("Skipped reading configuration file", logfields.Error, err)
		}

		// Check for the debug flag again now that the configuration file may has
		// been loaded, as it might have changed.
		if vp.GetBool(DebugArg) {
			logging.SetLogLevelToDebug()
		}
	}
}

// BPFEventBufferConfig contains parsed configuration for a bpf map event buffer.
type BPFEventBufferConfig struct {
	Enabled bool
	MaxSize int
	TTL     time.Duration
}

// BPFEventBufferConfigs contains parsed bpf event buffer configs, indexed but map name.
type BPFEventBufferConfigs map[string]BPFEventBufferConfig

// GetEventBufferConfig returns either the relevant config for a map name, or a default
// one with enabled=false otherwise.
func (d *DaemonConfig) GetEventBufferConfig(name string) BPFEventBufferConfig {
	return d.bpfMapEventConfigs.get(name)
}

func (cs BPFEventBufferConfigs) get(name string) BPFEventBufferConfig {
	return cs[name]
}

// ParseEventBufferTupleString parses a event buffer configuration tuple string.
// For example: enabled_100_24h
// Which refers to enabled=true, maxSize=100, ttl=24hours.
func ParseEventBufferTupleString(optsStr string) (BPFEventBufferConfig, error) {
	opts := strings.Split(optsStr, "_")
	enabled := false
	conf := BPFEventBufferConfig{}
	if len(opts) != 3 {
		return conf, fmt.Errorf("unexpected event buffer config value format, should be in format 'mapname=enabled_100_24h'")
	}

	if opts[0] != "enabled" && opts[0] != "disabled" {
		return conf, fmt.Errorf("could not parse event buffer enabled: must be either 'enabled' or 'disabled'")
	}
	if opts[0] == "enabled" {
		enabled = true
	}
	size, err := strconv.Atoi(opts[1])
	if err != nil {
		return conf, fmt.Errorf("could not parse event buffer maxSize int: %w", err)
	}
	ttl, err := time.ParseDuration(opts[2])
	if err != nil {
		return conf, fmt.Errorf("could not parse event buffer ttl duration: %w", err)
	}
	if size < 0 {
		return conf, fmt.Errorf("event buffer max size cannot be less than zero (%d)", conf.MaxSize)
	}
	conf.TTL = ttl
	conf.Enabled = enabled && size != 0
	conf.MaxSize = size
	return conf, nil
}

func parseBPFMapEventConfigs(confs BPFEventBufferConfigs, confMap map[string]string) error {
	for name, confStr := range confMap {
		conf, err := ParseEventBufferTupleString(confStr)
		if err != nil {
			return fmt.Errorf("unable to parse %s: %w", BPFMapEventBuffers, err)
		}
		confs[name] = conf
	}
	return nil
}

func (d *DaemonConfig) EnforceLXCFibLookup() bool {
	// See https://github.com/cilium/cilium/issues/27343 for the symptoms.
	//
	// We want to enforce FIB lookup if EndpointRoutes are enabled, because
	// this was a config dependency change which caused different behaviour
	// since v1.14.0-snapshot.2. We will remove this hack later, once we
	// have auto-device detection on by default.
	return d.EnableEndpointRoutes
}

func (d *DaemonConfig) GetZone(id uint8) string {
	return d.ReverseFixedZoneMapping[id]
}

func (d *DaemonConfig) GetZoneID(zone string) uint8 {
	return d.FixedZoneMapping[zone]
}
