Merge dae73eaa9c into 6ddeb7caed

Before this commit: the printing of a rule results in
a pointer address.

After this commit: the printing of a rules results in
a human-readable text.

Resolves: #104

Signed-off-by: Paul Greenberg <greenpau@outlook.com>

.gitignore

@@ -0,0 +1 @@
+nftables.test

README.md

@@ -21,4 +21,12 @@ the data types/API will be identified as more functionality is added.
 
 Contributions are very welcome!
 
+### Testing Changes
 
+Run the following commands to test your changes:
+
+```bash
+go test ./...
+go test -c github.com/google/nftables
+sudo ./nftables.test -test.v -run_system_tests
+```

expr/ct.go

@@ -138,3 +138,59 @@ func (e *Ct) unmarshal(fam byte, data []byte) error {
 	}
 	return ad.Err()
 }
+
+type CtHelper struct {
+	Name    string
+	L3Proto uint16
+	L4Proto uint8
+}
+
+func (c *CtHelper) marshal(fam byte) ([]byte, error) {
+	exprData, err := c.marshalData(fam)
+	if err != nil {
+		return nil, err
+	}
+
+	return netlink.MarshalAttributes([]netlink.Attribute{
+		{Type: unix.NFTA_EXPR_NAME, Data: []byte("cthelper\x00")},
+		{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: exprData},
+	})
+}
+
+func (c *CtHelper) marshalData(fam byte) ([]byte, error) {
+	exprData := []netlink.Attribute{
+		{Type: unix.NFTA_CT_HELPER_NAME, Data: []byte(c.Name)},
+	}
+
+	if c.L3Proto != 0 {
+		exprData = append(exprData, netlink.Attribute{
+			Type: unix.NFTA_CT_HELPER_L3PROTO, Data: binaryutil.BigEndian.PutUint16(c.L3Proto),
+		})
+	}
+	if c.L4Proto != 0 {
+		exprData = append(exprData, netlink.Attribute{
+			Type: unix.NFTA_CT_HELPER_L4PROTO, Data: []byte{c.L4Proto},
+		})
+	}
+
+	return netlink.MarshalAttributes(exprData)
+}
+
+func (c *CtHelper) unmarshal(fam byte, data []byte) error {
+	ad, err := netlink.NewAttributeDecoder(data)
+	if err != nil {
+		return err
+	}
+	ad.ByteOrder = binary.BigEndian
+	for ad.Next() {
+		switch ad.Type() {
+		case unix.NFTA_CT_HELPER_NAME:
+			c.Name = ad.String()
+		case unix.NFTA_CT_HELPER_L3PROTO:
+			c.L3Proto = ad.Uint16()
+		case unix.NFTA_CT_HELPER_L4PROTO:
+			c.L4Proto = ad.Uint8()
+		}
+	}
+	return ad.Err()
+}

expr/expr.go

@@ -197,6 +197,8 @@ func exprFromName(name string) Any {
 		e = &Masq{}
 	case "hash":
 		e = &Hash{}
+	case "cthelper":
+		e = &CtHelper{}
 	}
 	return e
 }

expr/verdict.go

@@ -24,6 +24,15 @@ import (
 	"golang.org/x/sys/unix"
 )
 
+const (
+	NFT_DROP   = 0
+	NFT_ACCEPT = 1
+	NFT_STOLEN = 2
+	NFT_QUEUE  = 3
+	NFT_REPEAT = 4
+	NFT_STOP   = 5
+)
+
 // This code assembles the verdict structure, as expected by the
 // nftables netlink API.
 // For further information, consult:
@@ -129,3 +138,37 @@ func (e *Verdict) unmarshal(fam byte, data []byte) error {
 	}
 	return ad.Err()
 }
+
+func (e *Verdict) String() string {
+	var v string
+	switch e.Kind {
+	case unix.NFT_RETURN:
+		v = "return" // -0x5
+	case unix.NFT_GOTO:
+		v = "goto" // -0x4
+	case unix.NFT_JUMP:
+		v = "jump" // NFT_JUMP = -0x3
+	case unix.NFT_BREAK:
+		v = "break" // NFT_BREAK = -0x2
+	case unix.NFT_CONTINUE:
+		v = "continue" // NFT_CONTINUE = -0x1
+	case NFT_DROP:
+		v = "drop"
+	case NFT_ACCEPT:
+		v = "accept"
+	case NFT_STOLEN:
+		v = "stolen"
+	case NFT_QUEUE:
+		v = "queue"
+	case NFT_REPEAT:
+		v = "repeat"
+	case NFT_STOP:
+		v = "stop"
+	default:
+		v = fmt.Sprintf("verdict %v", e.Kind)
+	}
+	if e.Chain != "" {
+		return v + " " + e.Chain
+	}
+	return v
+}

nftables_test.go

@@ -221,12 +221,27 @@ func TestRuleOperations(t *testing.T) {
 		expr.VerdictDrop,
 	}
 
+	wantStrings := []string{
+		"queue",
+		"accept",
+		"queue",
+		"accept",
+		"drop",
+		"drop",
+	}
+
 	for i, r := range rules {
 		rr, _ := r.Exprs[0].(*expr.Verdict)
 
 		if rr.Kind != want[i] {
 			t.Fatalf("bad verdict kind at %d", i)
 		}
+
+		if rr.String() != wantStrings[i] {
+			t.Fatalf("bad verdict string at %d: %s (received) vs. %s (expected)", i, rr.String(), wantStrings[i])
+		}
+
+		t.Logf("%s", rr)
 	}
 }
 
@@ -1383,6 +1398,65 @@ func TestCt(t *testing.T) {
 	}
 }
 
+func TestCtHelper(t *testing.T) {
+	conn, newNS := nftest.OpenSystemConn(t, *enableSysTests)
+	defer nftest.CleanupSystemConn(t, newNS)
+	conn.FlushRuleset()
+	defer conn.FlushRuleset()
+
+	table := conn.AddTable(&nftables.Table{
+		Family: nftables.TableFamilyIPv4,
+		Name:   "filter",
+	})
+
+	cthelp1 := conn.AddObj(&nftables.NamedObj{
+		Table: table,
+		Name:  "ftp-standard",
+		Type:  nftables.ObjTypeCtHelper,
+		Obj: &expr.CtHelper{
+			Name:    "ftp",
+			L4Proto: unix.IPPROTO_TCP,
+			L3Proto: unix.NFPROTO_IPV4,
+		},
+	})
+
+	if err := conn.Flush(); err != nil {
+		t.Fatalf(err.Error())
+	}
+
+	obj1, err := conn.GetObject(cthelp1)
+	if err != nil {
+		t.Errorf("c.GetObject(cthelp1) failed: %v failed", err)
+	}
+
+	helper, ok := obj1.(*nftables.NamedObj)
+	if !ok {
+		t.Fatalf("unexpected type: got %T, want *nftables.ObjAttr", obj1)
+	}
+
+	if got, want := helper.Name, "ftp-standard"; got != want {
+		t.Fatalf("unexpected counter name: got %s, want %s", got, want)
+	}
+
+	if _, err = conn.ResetObject(cthelp1); err != nil {
+		t.Errorf("c.ResetObjects(cthelp1) failed: %v failed", err)
+	}
+
+	obj1, err = conn.GetObject(cthelp1)
+	if err != nil {
+		t.Errorf("c.GetObject(cthelp1) failed: %v failed", err)
+	}
+
+	help := obj1.(*nftables.NamedObj).Obj.(*expr.CtHelper)
+	if got, want := help.L4Proto, uint8(unix.IPPROTO_TCP); got != want {
+		t.Errorf("unexpected l4proto number: got %d, want %d", got, want)
+	}
+
+	if got, want := help.L3Proto, uint16(unix.NFPROTO_IPV4); got != want {
+		t.Errorf("unexpected l3proto number: got %d, want %d", got, want)
+	}
+}
+
 func TestCtSet(t *testing.T) {
 	want := [][]byte{
 		// batch begin

nftables_test.sh

@@ -0,0 +1,3 @@
+go test ./...
+go test -c github.com/google/nftables
+sudo ./nftables.test -test.v -run_system_tests

obj.go

@@ -51,7 +51,7 @@ var objByObjTypeMagic = map[ObjType]string{
 	ObjTypeQuota:     "quota",
 	ObjTypeLimit:     "limit",
 	ObjTypeConnLimit: "connlimit",
-	ObjTypeCtHelper:  "cthelper",  // not implemented in expr
+	ObjTypeCtHelper:  "cthelper",
 	ObjTypeTunnel:    "tunnel",    // not implemented in expr
 	ObjTypeCtTimeout: "cttimeout", // not implemented in expr
 	ObjTypeSecMark:   "secmark",   // not implemented in expr