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Merge branch 'obj-ct-expect' into actions-test
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turekt committed Sep 5, 2024
2 parents 89968cc + b882be9 commit 61415fa
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Showing 5 changed files with 145 additions and 4 deletions.
3 changes: 3 additions & 0 deletions .github/workflows/push.yml
Original file line number Diff line number Diff line change
Expand Up @@ -32,4 +32,7 @@ jobs:
run: |
go test -c github.com/google/nftables
sudo nft --version
sudo nft flush ruleset
sudo nft add table inet filter
sudo nft add ct expectation inet filter expect {protocol tcp \; dport 53 \; timeout 2s \; size 1 \; l3proto ip \;}
sudo NLDEBUG=1 ./nftables.test -test.v -run_system_tests -test.run=TestCtExpect
67 changes: 67 additions & 0 deletions expr/ct.go
Original file line number Diff line number Diff line change
Expand Up @@ -194,3 +194,70 @@ func (c *CtHelper) unmarshal(fam byte, data []byte) error {
}
return ad.Err()
}

// From https://git.netfilter.org/libnftnl/tree/include/linux/netfilter/nf_tables.h?id=be0bae0ad31b0adb506f96de083f52a2bd0d4fbf#n1601
// Currently not available in sys/unix
const (
NFTA_CT_EXPECT_L3PROTO = 0x01
NFTA_CT_EXPECT_L4PROTO = 0x02
NFTA_CT_EXPECT_DPORT = 0x03
NFTA_CT_EXPECT_TIMEOUT = 0x04
NFTA_CT_EXPECT_SIZE = 0x05
)

type CtExpect struct {
L3Proto uint16
L4Proto uint8
DPort uint16
Timeout uint32
Size uint8
}

func (c *CtExpect) 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("ctexpect\x00")},
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: exprData},
})
}

func (c *CtExpect) marshalData(fam byte) ([]byte, error) {
// all elements must be defined
// per https://git.netfilter.org/nftables/tree/doc/stateful-objects.txt?id=db70959a5ccf2952b218f51c3d529e186a5a43bb#n119
exprData := []netlink.Attribute{
{Type: NFTA_CT_EXPECT_L3PROTO, Data: binaryutil.BigEndian.PutUint16(c.L3Proto)},
{Type: NFTA_CT_EXPECT_L4PROTO, Data: []byte{c.L4Proto}},
{Type: NFTA_CT_EXPECT_DPORT, Data: binaryutil.BigEndian.PutUint16(c.DPort)},
{Type: NFTA_CT_EXPECT_TIMEOUT, Data: binaryutil.BigEndian.PutUint32(c.Timeout)},
{Type: NFTA_CT_EXPECT_SIZE, Data: []byte{c.Size}},
}

return netlink.MarshalAttributes(exprData)
}

func (c *CtExpect) 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 NFTA_CT_EXPECT_L3PROTO:
c.L3Proto = ad.Uint16()
case NFTA_CT_EXPECT_L4PROTO:
c.L4Proto = ad.Uint8()
case NFTA_CT_EXPECT_DPORT:
c.DPort = ad.Uint16()
case NFTA_CT_EXPECT_TIMEOUT:
c.Timeout = ad.Uint32()
case NFTA_CT_EXPECT_SIZE:
c.Size = ad.Uint8()
}
}
return ad.Err()
}
2 changes: 2 additions & 0 deletions expr/expr.go
Original file line number Diff line number Diff line change
Expand Up @@ -201,6 +201,8 @@ func exprFromName(name string) Any {
e = &CtHelper{}
case "synproxy":
e = &SynProxy{}
case "ctexpect":
e = &CtExpect{}
}
return e
}
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73 changes: 71 additions & 2 deletions nftables_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -1428,7 +1428,6 @@ func TestSynProxyObject(t *testing.T) {
conn.AddObj(syn1)
conn.AddObj(syn2)
conn.AddObj(syn3)

if err := conn.Flush(); err != nil {
t.Fatalf(err.Error())
}
Expand All @@ -1437,7 +1436,6 @@ func TestSynProxyObject(t *testing.T) {
if err != nil {
t.Errorf("c.GetObjects(table) failed: %v", err)
}

if got, want := len(objs), 3; got != want {
t.Fatalf("received %d objects, expected %d", got, want)
}
Expand Down Expand Up @@ -1481,6 +1479,77 @@ func TestSynProxyObject(t *testing.T) {
}
}

func TestCtExpect(t *testing.T) {
conn, newNS := nftest.OpenSystemConn(t, *enableSysTests)
defer nftest.CleanupSystemConn(t, newNS)
conn.FlushRuleset()
defer conn.FlushRuleset()

// nft flush ruleset
// nft add table inet filter
// nft add ct expectation inet filter expect {protocol tcp \; dport 53 \; timeout 2s \; size 1 \; l3proto ip \;221}
table := conn.AddTable(&nftables.Table{
Family: nftables.TableFamilyINet,
Name: "filter",
})

cte := &nftables.NamedObj{
Table: table,
Name: "expect",
Type: nftables.ObjTypeCtExpect,
Obj: &expr.CtExpect{
// L3Proto: unix.NFPROTO_IPV4,
L4Proto: unix.IPPROTO_TCP,
DPort: 53,
Timeout: 20,
Size: 100,
},
}

conn.AddObj(cte)
if err := conn.Flush(); err != nil {
t.Fatalf(err.Error())
}

objs, err := conn.GetNamedObjects(table)
if err != nil {
t.Errorf("c.GetObjects(table) failed: %v", err)
}

if got, want := len(objs), 1; got != want {
t.Fatalf("received %d objects, expected %d", got, want)
}

obj := objs[0].(*nftables.NamedObj)
if got, want := obj.Name, cte.Name; got != want {
t.Errorf("object names are not equal: got %s, want %s", got, want)
}
if got, want := obj.Type, cte.Type; got != want {
t.Errorf("object types are not equal: got %v, want %v", got, want)
}
if got, want := obj.Table.Name, cte.Table.Name; got != want {
t.Errorf("object tables are not equal: got %s, want %s", got, want)
}

ce1 := obj.Obj.(*expr.CtExpect)
ce2 := cte.Obj.(*expr.CtExpect)
if got, want := ce1.L3Proto, ce2.L3Proto; got != want {
t.Errorf("object l3proto not equal: got %d, want %d", got, want)
}
if got, want := ce1.L4Proto, ce2.L4Proto; got != want {
t.Errorf("object l4proto not equal: got %d, want %d", got, want)
}
if got, want := ce1.DPort, ce2.DPort; got != want {
t.Errorf("object dport not equal: got %d, want %d", got, want)
}
if got, want := ce1.Size, ce2.Size; got != want {
t.Errorf("object Size not equal: got %d, want %d", got, want)
}
if got, want := ce1.Timeout, ce2.Timeout; got != want {
t.Errorf("object timeout not equal: got %d, want %d", got, want)
}
}

func TestCtHelper(t *testing.T) {
conn, newNS := nftest.OpenSystemConn(t, *enableSysTests)
defer nftest.CleanupSystemConn(t, newNS)
Expand Down
4 changes: 2 additions & 2 deletions obj.go
Original file line number Diff line number Diff line change
Expand Up @@ -55,8 +55,8 @@ var objByObjTypeMagic = map[ObjType]string{
ObjTypeTunnel: "tunnel", // not implemented in expr
ObjTypeCtTimeout: "cttimeout", // not implemented in expr
ObjTypeSecMark: "secmark", // not implemented in expr
ObjTypeCtExpect: "ctexpect", // not implemented in expr
ObjTypeSynProxy: "synproxy", // not implemented in expr
ObjTypeCtExpect: "ctexpect",
ObjTypeSynProxy: "synproxy",
}

// Obj represents a netfilter stateful object. See also
Expand Down

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