add felixConfiguration attr: natOutgoingExclusions

api/pkg/apis/projectcalico/v3/felixconfig.go

@@ -105,6 +105,14 @@ const (
 	WindowsManageFirewallRulesDisabled WindowsManageFirewallRulesMode = "Disabled"
 )
 
+// +kubebuilder:validation:Enum=IPPoolsOnly;IPPoolsAndHostIPs
+type NATOutgoingExclusionsType string
+
+const (
+	NATOutgoingExclusionsIPPoolsOnly       NATOutgoingExclusionsType = "IPPoolsOnly"
+	NATOutgoingExclusionsIPPoolsAndHostIPs NATOutgoingExclusionsType = "IPPoolsAndHostIPs"
+)
+
 // FelixConfigurationSpec contains the values of the Felix configuration.
 type FelixConfigurationSpec struct {
 	// UseInternalDataplaneDriver, if true, Felix will use its internal dataplane programming logic.  If false, it
@@ -465,6 +473,13 @@ type FelixConfigurationSpec struct {
 	// (i.e. it uses the iptables MASQUERADE target).
 	NATOutgoingAddress string `json:"natOutgoingAddress,omitempty"`
 
+	// When a IP pool setting `natOutgoing` is true, packets sent from Calico networked containers in this IP pool to destinations will be masqueraded.
+	// Configure which type of destinations is excluded from being masqueraded.
+	// - IPPoolsOnly: destinations outside of this IP pool will be masqueraded.
+	// - IPPoolsAndHostIPs: destinations outside of this IP pool and all hosts will be masqueraded.
+	// [Default: IPPoolsOnly]
+	NATOutgoingExclusions *NATOutgoingExclusionsType `json:"natOutgoingExclusions,omitempty" validate:"omitempty,oneof=IPPoolsOnly IPPoolsAndHostIPs"`
+
 	// DeviceRouteSourceAddress IPv4 address to set as the source hint for routes programmed by Felix. When not set
 	// the source address for local traffic from host to workload will be determined by the kernel.
 	DeviceRouteSourceAddress string `json:"deviceRouteSourceAddress,omitempty"`

felix/config/config_params.go

@@ -390,9 +390,10 @@ type Config struct {
 	FailsafeInboundHostPorts  []ProtoPort `config:"port-list;tcp:22,udp:68,tcp:179,tcp:2379,tcp:2380,tcp:5473,tcp:6443,tcp:6666,tcp:6667;die-on-fail"`
 	FailsafeOutboundHostPorts []ProtoPort `config:"port-list;udp:53,udp:67,tcp:179,tcp:2379,tcp:2380,tcp:5473,tcp:6443,tcp:6666,tcp:6667;die-on-fail"`
 
-	KubeNodePortRanges []numorstring.Port `config:"portrange-list;30000:32767"`
-	NATPortRange       numorstring.Port   `config:"portrange;"`
-	NATOutgoingAddress net.IP             `config:"ipv4;"`
+	KubeNodePortRanges    []numorstring.Port `config:"portrange-list;30000:32767"`
+	NATPortRange          numorstring.Port   `config:"portrange;"`
+	NATOutgoingAddress    net.IP             `config:"ipv4;"`
+	NATOutgoingExclusions string             `config:"oneof(IPPoolsOnly,IPPoolsAndHostIPs);IPPoolsOnly"`
 
 	UsageReportingEnabled          bool          `config:"bool;true"`
 	UsageReportingInitialDelaySecs time.Duration `config:"seconds;300"`

felix/dataplane/driver.go

@@ -277,6 +277,7 @@ func StartDataplaneDriver(configParams *config.Config,
 				NATPortRange:                       configParams.NATPortRange,
 				IptablesNATOutgoingInterfaceFilter: configParams.IptablesNATOutgoingInterfaceFilter,
 				NATOutgoingAddress:                 configParams.NATOutgoingAddress,
+				NATOutgoingExclusions:              configParams.NATOutgoingExclusions,
 				BPFEnabled:                         configParams.BPFEnabled,
 				BPFForceTrackPacketsFromIfaces:     replaceWildcards(configParams.NFTablesMode == "Enabled", configParams.BPFForceTrackPacketsFromIfaces),
 				ServiceLoopPrevention:              configParams.ServiceLoopPrevention,

felix/rules/nat.go

@@ -19,6 +19,7 @@ import (
 	"sort"
 	"strings"
 
+	apiv3 "github.com/projectcalico/api/pkg/apis/projectcalico/v3"
 	tcdefs "github.com/projectcalico/calico/felix/bpf/tc/defs"
 	. "github.com/projectcalico/calico/felix/generictables"
 )
@@ -58,6 +59,12 @@ func (r *DefaultRuleRenderer) makeNATOutgoingRuleIPTables(ipVersion uint8, proto
 		SourceIPSet(masqIPsSetName).
 		NotDestIPSet(allIPsSetName)
 
+	check := apiv3.NATOutgoingExclusionsType(r.Config.NATOutgoingExclusions)
+	if check == apiv3.NATOutgoingExclusionsIPPoolsAndHostIPs {
+		allHostsIPsSetName := ipConf.NameForMainIPSet(IPSetIDAllHostNets)
+		match = match.NotDestIPSet(allHostsIPsSetName)
+	}
+
 	if protocol != "" {
 		match = match.Protocol(protocol)
 	}

felix/rules/nat_test.go

@@ -59,6 +59,24 @@ var _ = Describe("NAT", func() {
 			},
 		}))
 	})
+	It("should render rules when active with all hosts NAT exclusion", func() {
+		localConfig := rrConfigNormal
+		rrConfigNormal.NATOutgoingExclusions = "IPPoolsAndHostIPs"
+		renderer = NewRenderer(localConfig)
+
+		Expect(renderer.NATOutgoingChain(true, 4)).To(Equal(&generictables.Chain{
+			Name: "cali-nat-outgoing",
+			Rules: []generictables.Rule{
+				{
+					Action: MasqAction{},
+					Match: Match().
+						SourceIPSet("cali40masq-ipam-pools").
+						NotDestIPSet("cali40all-ipam-pools").
+						NotDestIPSet("cali40all-hosts-net"),
+				},
+			},
+		}))
+	})
 	It("should render rules when active with an explicit SNAT address", func() {
 		snatAddress := "192.168.0.1"
 		localConfig := rrConfigNormal

felix/rules/rule_defs.go

@@ -354,6 +354,7 @@ type Config struct {
 	IptablesNATOutgoingInterfaceFilter string
 
 	NATOutgoingAddress             net.IP
+	NATOutgoingExclusions          string
 	BPFEnabled                     bool
 	BPFForceTrackPacketsFromIfaces []string
 	ServiceLoopPrevention          string