IPMode                  = pm.IPMode
)

const (
	SidecarProxy = pm.SidecarProxy
	Router       = pm.Router
	Waypoint     = pm.Waypoint
	Ztunnel      = pm.Ztunnel

	IPv4 = pm.IPv4
	IPv6 = pm.IPv6
	Dual = pm.Dual
)

var _ mesh.Holder = &Environment{}

func NewEnvironment() *Environment {
	var cache XdsCache
	if features.EnableXDSCaching {
		cache = NewXdsCache()
	} else {

		nt = proto.Clone(nt).(*dnsProto.NameTable)
		a.localDNSServer.BuildAlternateHosts(nt, func(althosts map[string]struct{}, ipv4 []netip.Addr, ipv6 []netip.Addr, _ []string) {
			for host := range althosts {
				if _, exists := nt.Table[host]; !exists {
					addresses := make([]string, 0, len(ipv4)+len(ipv6))
					for _, addr := range ipv4 {
						addresses = append(addresses, addr.String())
					}
					for _, addr := range ipv6 {

		}
	default:
		unStrmDgramEnabled = true
	}
}

func unixStrmDgramEnabled() bool {
	stackOnce.Do(probeStack)
	return unStrmDgramEnabled
}

// SupportsIPv4 reports whether the platform supports IPv4 networking
// functionality.
func SupportsIPv4() bool {
	stackOnce.Do(probeStack)
	return ipv4Enabled
}

// SupportsIPv6 reports whether the platform supports IPv6 networking
// functionality.

    spec:
      securityContext:
      {{- if .Values.gateways.securityContext }}
        {{- toYaml .Values.gateways.securityContext | nindent 8 }}
      {{- else }}
        sysctls:
        - name: net.ipv4.ip_unprivileged_port_start
          value: "0"
      {{- end }}
      serviceAccountName: {{.ServiceAccount | quote}}
      containers:
      - name: istio-proxy

				if err = fd.pd.waitRead(fd.isFile); err == nil {
					continue
				}
			}
		}
		err = fd.eofError(n, err)
		return n, sa, err
	}
}

// ReadFromInet4 wraps the recvfrom network call for IPv4.
func (fd *FD) ReadFromInet4(p []byte, from *syscall.SockaddrInet4) (int, error) {
	if err := fd.readLock(); err != nil {
		return 0, err
	}
	defer fd.readUnlock()

		expectedAddr    string
		expectedPort    uint32
	}{
		// ipv4 use cases
		{
			name:            "ipv4 host: defaultEndpoint set to 127.0.0.1:7073",
			proxy:           ipv4Proxy,
			defaultEndpoint: "127.0.0.1:7073",
			expectedAddr:    "127.0.0.1",
			expectedPort:    7073,
		},
		{
			name:            "ipv4 host: defaultEndpoint set to [::1]:7073",
			proxy:           ipv4Proxy,

// here to reuse a single install across tests.
func TestMain(m *testing.M) {
	// nolint: staticcheck
	framework.
		NewSuite(m).
		RequireMinVersion(24).
		Label(label.IPv4). // https://github.com/istio/istio/issues/41008
		Setup(func(t resource.Context) error {
			t.Settings().Ambient = true
			return nil
		}).
		Setup(istio.Setup(&i, func(ctx resource.Context, cfg *istio.Config) {

	// performance over iptables debuggability
	largeClusterEndpointsThreshold = 1000
)

const sysctlRouteLocalnet = "net/ipv4/conf/all/route_localnet"
const sysctlNFConntrackTCPBeLiberal = "net/netfilter/nf_conntrack_tcp_be_liberal"

// NewDualStackProxier creates a MetaProxier instance, with IPv4 and IPv6 proxies.
func NewDualStackProxier(
	ctx context.Context,
	ipt [2]utiliptables.Interface,
	sysctl utilsysctl.Interface,

) (proxy.Provider, error) {
	// Create an ipv4 instance of the single-stack proxier
	ipv4Proxier, err := NewProxier(ctx, v1.IPv4Protocol,
		syncPeriod, minSyncPeriod, masqueradeAll, masqueradeBit,
		localDetectors[v1.IPv4Protocol], hostname, nodeIPs[v1.IPv4Protocol],
		recorder, healthzServer, nodePortAddresses, initOnly)
	if err != nil {
		return nil, fmt.Errorf("unable to create ipv4 proxier: %v", err)
	}

		expectedFamily cluster.Cluster_DnsLookupFamily
	}{
		{
			name:           "all ipv4, dual stack disabled",
			clusterName:    "foo",
			discovery:      cluster.Cluster_STRICT_DNS,
			proxy:          getProxy(),
			dualStack:      false,
			expectedFamily: cluster.Cluster_V4_ONLY,
		},
		{
			name:           "all ipv4, dual stack enabled",
			clusterName:    "foo",