Add address field for expr tproxy (#231)

* Add address field for expr tproxy Signed-off-by: black-desk <me@black-desk.cn> Co-authored-by: MrRedhat <Redhatminzhe@Gmail.com>
google · Jul 10, 2023 · 8a10f68 · 8a10f68
1 parent 8f2d395
commit 8a10f68
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Showing 2 changed files with 88 additions and 6 deletions.
diff --git a/expr/tproxy.go b/expr/tproxy.go
@@ -25,22 +25,34 @@ import (
 const (
 	// NFTA_TPROXY_FAMILY defines attribute for a table family
 	NFTA_TPROXY_FAMILY = 0x01
-	// NFTA_TPROXY_REG defines attribute for a register carrying redirection port value
-	NFTA_TPROXY_REG = 0x03
+	// NFTA_TPROXY_REG_ADDR defines attribute for a register carrying redirection address value
+	NFTA_TPROXY_REG_ADDR = 0x02
+	// NFTA_TPROXY_REG_PORT defines attribute for a register carrying redirection port value
+	NFTA_TPROXY_REG_PORT = 0x03
 )
 
 // TProxy defines struct with parameters for the transparent proxy
 type TProxy struct {
 	Family      byte
 	TableFamily byte
+	RegAddr     uint32
 	RegPort     uint32
 }
 
 func (e *TProxy) marshal(fam byte) ([]byte, error) {
-	data, err := netlink.MarshalAttributes([]netlink.Attribute{
+	attrs := []netlink.Attribute{
 		{Type: NFTA_TPROXY_FAMILY, Data: binaryutil.BigEndian.PutUint32(uint32(e.Family))},
-		{Type: NFTA_TPROXY_REG, Data: binaryutil.BigEndian.PutUint32(e.RegPort)},
-	})
+		{Type: NFTA_TPROXY_REG_PORT, Data: binaryutil.BigEndian.PutUint32(e.RegPort)},
+	}
+
+	if e.RegAddr != 0 {
+		attrs = append(attrs, netlink.Attribute{
+			Type: NFTA_TPROXY_REG_ADDR,
+			Data: binaryutil.BigEndian.PutUint32(e.RegAddr),
+		})
+	}
+
+	data, err := netlink.MarshalAttributes(attrs)
 	if err != nil {
 		return nil, err
 	}
@@ -60,8 +72,10 @@ func (e *TProxy) unmarshal(fam byte, data []byte) error {
 		switch ad.Type() {
 		case NFTA_TPROXY_FAMILY:
 			e.Family = ad.Uint8()
-		case NFTA_TPROXY_REG:
+		case NFTA_TPROXY_REG_PORT:
 			e.RegPort = ad.Uint32()
+		case NFTA_TPROXY_REG_ADDR:
+			e.RegAddr = ad.Uint32()
 		}
 	}
 	return ad.Err()

diff --git a/nftables_test.go b/nftables_test.go
@@ -1206,6 +1206,74 @@ func TestTProxy(t *testing.T) {
 	}
 }
 
+func TestTProxyWithAddrField(t *testing.T) {
+	want := [][]byte{
+		// batch begin
+		[]byte("\x00\x00\x00\x0a"),
+		// nft add rule filter divert ip protocol tcp tproxy to 10.10.72.1:50080
+		[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0b\x00\x02\x00\x64\x69\x76\x65\x72\x74\x00\x00\xe8\x00\x04\x80\x34\x00\x01\x80\x0c\x00\x01\x00\x70\x61\x79\x6c\x6f\x61\x64\x00\x24\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x08\x00\x02\x00\x00\x00\x00\x01\x08\x00\x03\x00\x00\x00\x00\x09\x08\x00\x04\x00\x00\x00\x00\x01\x2c\x00\x01\x80\x08\x00\x01\x00\x63\x6d\x70\x00\x20\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x08\x00\x02\x00\x00\x00\x00\x00\x0c\x00\x03\x80\x05\x00\x01\x00\x06\x00\x00\x00\x2c\x00\x01\x80\x0e\x00\x01\x00\x69\x6d\x6d\x65\x64\x69\x61\x74\x65\x00\x00\x00\x18\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x0c\x00\x02\x80\x08\x00\x01\x00\x0a\x0a\x48\x01\x2c\x00\x01\x80\x0e\x00\x01\x00\x69\x6d\x6d\x65\x64\x69\x61\x74\x65\x00\x00\x00\x18\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x02\x0c\x00\x02\x80\x06\x00\x01\x00\xc3\xa0\x00\x00\x2c\x00\x01\x80\x0b\x00\x01\x00\x74\x70\x72\x6f\x78\x79\x00\x00\x1c\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x02\x08\x00\x03\x00\x00\x00\x00\x02\x08\x00\x02\x00\x00\x00\x00\x01"),
+		// batch end
+		[]byte("\x00\x00\x00\x0a"),
+	}
+
+	c, err := nftables.New(nftables.WithTestDial(
+		func(req []netlink.Message) ([]netlink.Message, error) {
+			for idx, msg := range req {
+				b, err := msg.MarshalBinary()
+				if err != nil {
+					t.Fatal(err)
+				}
+				if len(b) < 16 {
+					continue
+				}
+				b = b[16:]
+				if len(want) == 0 {
+					t.Errorf("no want entry for message %d: %x", idx, b)
+					continue
+				}
+				if got, want := b, want[0]; !bytes.Equal(got, want) {
+					t.Errorf("message %d: %s", idx, linediff(nfdump(got), nfdump(want)))
+				}
+				want = want[1:]
+			}
+			return req, nil
+		}))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	c.AddRule(&nftables.Rule{
+		Table: &nftables.Table{Name: "filter", Family: nftables.TableFamilyIPv4},
+		Chain: &nftables.Chain{
+			Name:     "divert",
+			Type:     nftables.ChainTypeFilter,
+			Hooknum:  nftables.ChainHookPrerouting,
+			Priority: nftables.ChainPriorityRef(-150),
+		},
+		Exprs: []expr.Any{
+			//	[ payload load 1b @ network header + 9 => reg 1 ]
+			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseNetworkHeader, Offset: 9, Len: 1},
+			//	[ cmp eq reg 1 0x00000006 ]
+			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: []byte{unix.IPPROTO_TCP}},
+			//	[ immediate reg 1 0x01480a0a ]
+			&expr.Immediate{Register: 1, Data: []byte("\x0a\x0a\x48\x01")},
+			//	[ immediate reg 2 0x0000a0c3 ]
+			&expr.Immediate{Register: 2, Data: binaryutil.BigEndian.PutUint16(50080)},
+			//	[ tproxy ip addr reg 1 port reg 2 ]
+			&expr.TProxy{
+				Family:      byte(nftables.TableFamilyIPv4),
+				TableFamily: byte(nftables.TableFamilyIPv4),
+				RegAddr:     1,
+				RegPort:     2,
+			},
+		},
+	})
+
+	if err := c.Flush(); err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestCt(t *testing.T) {
 	want := [][]byte{
 		// batch begin