Add integration tests for nftables package

This commit adds integration tests to the nftables package to verify
that the Go code correctly programs nftables rules. The tests use
external nftables scripts to define the expected state and compare
it with the state produced by the Go code.

Change-Id: I9c8439ee462b4882b221e6244f53379b822446dc
Signed-off-by: Antonio Ojea <aojea@google.com>

.github/workflows/push.yml

@@ -33,3 +33,5 @@ jobs:
         go test ./...
         go test -c github.com/google/nftables
         sudo ./nftables.test -test.v -run_system_tests
+        go test -c github.com/google/nftables/integration
+        (cd integration && sudo ../integration.test -test.v -run_system_tests)

go.mod

@@ -3,13 +3,14 @@ module github.com/google/nftables
 go 1.21
 
 require (
+	github.com/google/go-cmp v0.6.0
 	github.com/mdlayher/netlink v1.7.3-0.20250113171957-fbb4dce95f42
-	github.com/vishvananda/netns v0.0.0-20180720170159-13995c7128cc
+	github.com/vishvananda/netlink v1.3.0
+	github.com/vishvananda/netns v0.0.4
 	golang.org/x/sys v0.28.0
 )
 
 require (
-	github.com/google/go-cmp v0.6.0 // indirect
 	github.com/mdlayher/socket v0.5.0 // indirect
 	golang.org/x/net v0.33.0 // indirect
 	golang.org/x/sync v0.6.0 // indirect

go.sum

@@ -4,11 +4,15 @@ github.com/mdlayher/netlink v1.7.3-0.20250113171957-fbb4dce95f42 h1:A1Cq6Ysb0GM0
 github.com/mdlayher/netlink v1.7.3-0.20250113171957-fbb4dce95f42/go.mod h1:BB4YCPDOzfy7FniQ/lxuYQ3dgmM2cZumHbK8RpTjN2o=
 github.com/mdlayher/socket v0.5.0 h1:ilICZmJcQz70vrWVes1MFera4jGiWNocSkykwwoy3XI=
 github.com/mdlayher/socket v0.5.0/go.mod h1:WkcBFfvyG8QENs5+hfQPl1X6Jpd2yeLIYgrGFmJiJxI=
-github.com/vishvananda/netns v0.0.0-20180720170159-13995c7128cc h1:R83G5ikgLMxrBvLh22JhdfI8K6YXEPHx5P03Uu3DRs4=
-github.com/vishvananda/netns v0.0.0-20180720170159-13995c7128cc/go.mod h1:ZjcWmFBXmLKZu9Nxj3WKYEafiSqer2rnvPr0en9UNpI=
+github.com/vishvananda/netlink v1.3.0 h1:X7l42GfcV4S6E4vHTsw48qbrV+9PVojNfIhZcwQdrZk=
+github.com/vishvananda/netlink v1.3.0/go.mod h1:i6NetklAujEcC6fK0JPjT8qSwWyO0HLn4UKG+hGqeJs=
+github.com/vishvananda/netns v0.0.4 h1:Oeaw1EM2JMxD51g9uhtC0D7erkIjgmj8+JZc26m1YX8=
+github.com/vishvananda/netns v0.0.4/go.mod h1:SpkAiCQRtJ6TvvxPnOSyH3BMl6unz3xZlaprSwhNNJM=
 golang.org/x/net v0.33.0 h1:74SYHlV8BIgHIFC/LrYkOGIwL19eTYXQ5wc6TBuO36I=
 golang.org/x/net v0.33.0/go.mod h1:HXLR5J+9DxmrqMwG9qjGCxZ+zKXxBru04zlTvWlWuN4=
 golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
 golang.org/x/sync v0.6.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
 golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

integration/nft_test.go

@@ -0,0 +1,252 @@
+// Copyright 2025 Google LLC. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package integration
+
+import (
+	"flag"
+	"os/exec"
+	"strings"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/nftables"
+	"github.com/google/nftables/binaryutil"
+	"github.com/google/nftables/expr"
+	"github.com/google/nftables/internal/nftest"
+	"github.com/vishvananda/netlink"
+)
+
+var enableSysTests = flag.Bool("run_system_tests", false, "Run tests that operate against the live kernel")
+
+func ifname(n string) []byte {
+	b := make([]byte, 16)
+	copy(b, []byte(n+"\x00"))
+	return b
+}
+
+func TestNFTables(t *testing.T) {
+	tests := []struct {
+		name          string
+		scriptPath    string
+		goCommands    func(t *testing.T, c *nftables.Conn)
+		expectFailure bool
+	}{
+		{
+			name:       "AddTable",
+			scriptPath: "testdata/add_table.nft",
+			goCommands: func(t *testing.T, c *nftables.Conn) {
+				c.FlushRuleset()
+
+				c.AddTable(&nftables.Table{
+					Name:   "test-table",
+					Family: nftables.TableFamilyINet,
+				})
+
+				err := c.Flush()
+				if err != nil {
+					t.Fatalf("Error creating table: %v", err)
+				}
+			},
+		},
+		{
+			name:       "AddChain",
+			scriptPath: "testdata/add_chain.nft",
+			goCommands: func(t *testing.T, c *nftables.Conn) {
+				c.FlushRuleset()
+
+				table := c.AddTable(&nftables.Table{
+					Name:   "test-table",
+					Family: nftables.TableFamilyINet,
+				})
+
+				c.AddChain(&nftables.Chain{
+					Name:     "test-chain",
+					Table:    table,
+					Hooknum:  nftables.ChainHookOutput,
+					Priority: nftables.ChainPriorityNATDest,
+					Type:     nftables.ChainTypeNAT,
+				})
+
+				err := c.Flush()
+				if err != nil {
+					t.Fatalf("Error creating table: %v", err)
+				}
+			},
+		},
+		{
+			name:       "AddFlowtables",
+			scriptPath: "testdata/add_flowtables.nft",
+			goCommands: func(t *testing.T, c *nftables.Conn) {
+				devices := []string{"dummy0"}
+				c.FlushRuleset()
+				// add + delete + add for flushing all the table
+				table := c.AddTable(&nftables.Table{
+					Family: nftables.TableFamilyINet,
+					Name:   "test-table",
+				})
+
+				devicesSet := &nftables.Set{
+					Table:        table,
+					Name:         "test-set",
+					KeyType:      nftables.TypeIFName,
+					KeyByteOrder: binaryutil.NativeEndian,
+				}
+
+				elements := []nftables.SetElement{}
+				for _, dev := range devices {
+					elements = append(elements, nftables.SetElement{
+						Key: ifname(dev),
+					})
+				}
+
+				if err := c.AddSet(devicesSet, elements); err != nil {
+					t.Errorf("failed to add Set %s : %v", devicesSet.Name, err)
+				}
+
+				flowtable := &nftables.Flowtable{
+					Table:    table,
+					Name:     "test-flowtable",
+					Devices:  devices,
+					Hooknum:  nftables.FlowtableHookIngress,
+					Priority: nftables.FlowtablePriorityRef(5),
+				}
+				c.AddFlowtable(flowtable)
+
+				chain := c.AddChain(&nftables.Chain{
+					Name:     "test-chain",
+					Table:    table,
+					Type:     nftables.ChainTypeFilter,
+					Hooknum:  nftables.ChainHookForward,
+					Priority: nftables.ChainPriorityMangle,
+				})
+
+				c.AddRule(&nftables.Rule{
+					Table: table,
+					Chain: chain,
+					Exprs: []expr.Any{
+						&expr.Meta{Key: expr.MetaKeyIIFNAME, SourceRegister: false, Register: 0x1},
+						&expr.Lookup{SourceRegister: 0x1, DestRegister: 0x0, IsDestRegSet: false, SetName: "test-set", Invert: true},
+						&expr.Verdict{Kind: expr.VerdictReturn},
+					},
+				})
+
+				c.AddRule(&nftables.Rule{
+					Table: table,
+					Chain: chain,
+					Exprs: []expr.Any{
+						&expr.Meta{Key: expr.MetaKeyOIFNAME, SourceRegister: false, Register: 0x1},
+						&expr.Lookup{SourceRegister: 0x1, DestRegister: 0x0, IsDestRegSet: false, SetName: "test-set", Invert: true},
+						&expr.Verdict{Kind: expr.VerdictReturn},
+					},
+				})
+
+				c.AddRule(&nftables.Rule{
+					Table: table,
+					Chain: chain,
+					Exprs: []expr.Any{
+						&expr.Ct{Register: 0x1, SourceRegister: false, Key: expr.CtKeySTATE, Direction: 0x0},
+						&expr.Bitwise{SourceRegister: 0x1, DestRegister: 0x1, Len: 0x4, Mask: binaryutil.NativeEndian.PutUint32(expr.CtStateBitESTABLISHED), Xor: binaryutil.NativeEndian.PutUint32(0)},
+						&expr.Cmp{Op: 0x1, Register: 0x1, Data: []uint8{0x0, 0x0, 0x0, 0x0}},
+						&expr.Ct{Register: 0x1, SourceRegister: false, Key: expr.CtKeyPKTS, Direction: 0x0},
+						&expr.Cmp{Op: expr.CmpOpGt, Register: 0x1, Data: binaryutil.NativeEndian.PutUint64(20)},
+						&expr.FlowOffload{Name: "test-flowtable"},
+						&expr.Counter{},
+					},
+				})
+
+				if err := c.Flush(); err != nil {
+					t.Fatal(err)
+				}
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Create a new network namespace to test these operations,
+			// and tear down the namespace at test completion.
+			c, newNS := nftest.OpenSystemConn(t, *enableSysTests)
+			defer nftest.CleanupSystemConn(t, newNS)
+
+			// Real interface must exist otherwise some nftables will fail
+			la := netlink.NewLinkAttrs()
+			la.Name = "dummy0"
+			dummy := &netlink.Dummy{LinkAttrs: la}
+			if err := netlink.LinkAdd(dummy); err != nil {
+				t.Fatal(err)
+			}
+
+			scriptOutput, err := applyNFTRuleset(tt.scriptPath)
+			if err != nil {
+				t.Fatalf("Failed to apply nftables script: %v\noutput:%s", err, scriptOutput)
+			}
+			if len(scriptOutput) > 0 {
+				t.Logf("nft output:\n%s", scriptOutput)
+			}
+
+			// Retrieve nftables state using nft
+			expectedOutput, err := listNFTRuleset()
+			if err != nil {
+				t.Fatalf("Failed to list nftables ruleset: %v\noutput:%s", err, expectedOutput)
+			}
+			t.Logf("Expected output:\n%s", expectedOutput)
+
+			// Program nftables using your Go code
+			if err := flushNFTRuleset(); err != nil {
+				t.Fatalf("Failed to flush nftables ruleset: %v", err)
+			}
+			tt.goCommands(t, c)
+
+			// Retrieve nftables state using nft
+			actualOutput, err := listNFTRuleset()
+			if err != nil {
+				t.Fatalf("Failed to list nftables ruleset: %v\noutput:%s", err, actualOutput)
+			}
+
+			t.Logf("Actual output:\n%s", actualOutput)
+
+			if expectedOutput != actualOutput {
+				t.Errorf("nftables ruleset mismatch:\n%s", cmp.Diff(expectedOutput, actualOutput))
+			}
+
+			if err := flushNFTRuleset(); err != nil {
+				t.Fatalf("Failed to flush nftables ruleset: %v", err)
+			}
+		})
+	}
+}
+
+func applyNFTRuleset(scriptPath string) (string, error) {
+	cmd := exec.Command("nft", "--debug=all", "-f", scriptPath)
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return string(out), err
+	}
+	return strings.TrimSpace(string(out)), nil
+}
+
+func listNFTRuleset() (string, error) {
+	cmd := exec.Command("nft", "list", "ruleset")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return string(out), err
+	}
+	return strings.TrimSpace(string(out)), nil
+}
+
+func flushNFTRuleset() error {
+	cmd := exec.Command("nft", "flush", "ruleset")
+	return cmd.Run()
+}

integration/testdata/add_chain.nft

@@ -0,0 +1,5 @@
+table inet test-table {
+        chain test-chain {
+                type nat hook output priority dstnat; policy accept;
+        }
+}

integration/testdata/add_flowtables.nft

@@ -0,0 +1,18 @@
+table inet test-table {
+        set test-set {
+                type ifname
+                elements = { "dummy0" }
+        }
+
+        flowtable test-flowtable {
+                hook ingress priority filter + 5
+                devices = { dummy0 }
+        }
+
+        chain test-chain {
+                type filter hook forward priority mangle; policy accept;
+                iifname != @test-set return
+                oifname != @test-set return
+                ct state established ct packets > 20 flow add @test-flowtable counter packets 0 bytes 0
+        }
+}

integration/testdata/add_table.nft

@@ -0,0 +1,2 @@
+table inet test-table {
+}