Implement range expression (#22)
Signed-off-by: Serguei Bezverkhi <sbezverk@cisco.com> fixes #19
This commit is contained in:
Serguei Bezverkhi
Michael Stapelberg
parent
8cccfeed7c
commit
8d26daf060
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@ -0,0 +1,98 @@
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// Copyright 2019 Google LLC. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package expr
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import (
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"encoding/binary"
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"github.com/google/nftables/binaryutil"
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"github.com/mdlayher/netlink"
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"golang.org/x/sys/unix"
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)
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// Range implements range expression
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type Range struct {
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Op CmpOp
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Register uint32
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FromData []byte
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ToData []byte
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}
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func (e *Range) marshal() ([]byte, error) {
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var attrs []netlink.Attribute
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var err error
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var rangeFromData, rangeToData []byte
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if e.Register > 0 {
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attrs = append(attrs, netlink.Attribute{Type: unix.NFTA_RANGE_SREG, Data: binaryutil.BigEndian.PutUint32(e.Register)})
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}
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attrs = append(attrs, netlink.Attribute{Type: unix.NFTA_RANGE_OP, Data: binaryutil.BigEndian.PutUint32(uint32(e.Op))})
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if len(e.FromData) > 0 {
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rangeFromData, err = nestedAttr(e.FromData, unix.NFTA_RANGE_FROM_DATA)
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if err != nil {
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return nil, err
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}
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}
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if len(e.ToData) > 0 {
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rangeToData, err = nestedAttr(e.ToData, unix.NFTA_RANGE_TO_DATA)
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if err != nil {
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return nil, err
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}
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}
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data, err := netlink.MarshalAttributes(attrs)
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if err != nil {
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return nil, err
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}
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data = append(data, rangeFromData...)
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data = append(data, rangeToData...)
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return netlink.MarshalAttributes([]netlink.Attribute{
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{Type: unix.NFTA_EXPR_NAME, Data: []byte("range\x00")},
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{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: data},
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})
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}
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func (e *Range) unmarshal(data []byte) error {
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ad, err := netlink.NewAttributeDecoder(data)
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if err != nil {
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return err
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}
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ad.ByteOrder = binary.BigEndian
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for ad.Next() {
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switch ad.Type() {
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case unix.NFTA_RANGE_OP:
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e.Op = CmpOp(ad.Uint32())
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case unix.NFTA_RANGE_SREG:
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e.Register = ad.Uint32()
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case unix.NFTA_RANGE_FROM_DATA:
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e.FromData = ad.Bytes()
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case unix.NFTA_RANGE_TO_DATA:
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e.ToData = ad.Bytes()
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}
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}
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return ad.Err()
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}
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func nestedAttr(data []byte, attrType uint16) ([]byte, error) {
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ae := netlink.NewAttributeEncoder()
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ae.Do(unix.NLA_F_NESTED|attrType, func() ([]byte, error) {
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nae := netlink.NewAttributeEncoder()
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nae.ByteOrder = binary.BigEndian
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nae.Bytes(unix.NFTA_DATA_VALUE, data)
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return nae.Encode()
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})
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return ae.Encode()
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}
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281
nftables_test.go
281
nftables_test.go
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@ -1536,3 +1536,284 @@ func TestConfigureReturnVerdict(t *testing.T) {
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t.Fatal(err)
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}
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}
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func TestConfigureRangePort(t *testing.T) {
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// The want byte sequences come from stracing nft(8), e.g.:
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// strace -f -v -x -s 2048 -eraw=sendto nft add rule filter forward tcp sport != 2024-2030 return
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//
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// The nft(8) command sequence was taken from:
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// https://wiki.nftables.org/wiki-nftables/index.php/Quick_reference-nftables_in_10_minutes#Tcp
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want := [][]byte{
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// batch begin
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[]byte("\x00\x00\x00\x0a"),
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// nft flush ruleset
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[]byte("\x00\x00\x00\x00"),
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// nft add table ip filter
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[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x08\x00\x02\x00\x00\x00\x00\x00"),
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// nft add chain filter forward '{' type filter hook forward priority 0 \; '}'
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[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0c\x00\x03\x00\x66\x6f\x72\x77\x61\x72\x64\x00\x14\x00\x04\x80\x08\x00\x01\x00\x00\x00\x00\x02\x08\x00\x02\x00\x00\x00\x00\x00\x0b\x00\x07\x00\x66\x69\x6c\x74\x65\x72\x00\x00"),
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// nft add rule filter forward tcp sport != 2024-2030 return
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[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0c\x00\x02\x00\x66\x6f\x72\x77\x61\x72\x64\x00\xf4\x00\x04\x80\x24\x00\x01\x80\x09\x00\x01\x00\x6d\x65\x74\x61\x00\x00\x00\x00\x14\x00\x02\x80\x08\x00\x02\x00\x00\x00\x00\x10\x08\x00\x01\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\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\x02\x08\x00\x03\x00\x00\x00\x00\x00\x08\x00\x04\x00\x00\x00\x00\x02\x3c\x00\x01\x80\x0a\x00\x01\x00\x72\x61\x6e\x67\x65\x00\x00\x00\x2c\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x08\x00\x02\x00\x00\x00\x00\x01\x0c\x00\x03\x80\x06\x00\x01\x00\x07\xe8\x00\x00\x0c\x00\x04\x80\x06\x00\x01\x00\x07\xee\x00\x00\x30\x00\x01\x80\x0e\x00\x01\x00\x69\x6d\x6d\x65\x64\x69\x61\x74\x65\x00\x00\x00\x1c\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x00\x10\x00\x02\x80\x0c\x00\x02\x80\x08\x00\x01\x00\xff\xff\xff\xfb"),
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// batch end
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[]byte("\x00\x00\x00\x0a"),
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}
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c := &nftables.Conn{
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TestDial: func(req []netlink.Message) ([]netlink.Message, error) {
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for idx, msg := range req {
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b, err := msg.MarshalBinary()
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if err != nil {
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t.Fatal(err)
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}
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if len(b) < 16 {
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continue
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}
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b = b[16:]
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if len(want) == 0 {
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t.Errorf("no want entry for message %d: %x", idx, b)
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continue
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}
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if got, want := b, want[0]; !bytes.Equal(got, want) {
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t.Errorf("message %d: %s", idx, linediff(nfdump(got), nfdump(want)))
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}
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want = want[1:]
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}
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return req, nil
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},
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}
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c.FlushRuleset()
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filter := c.AddTable(&nftables.Table{
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Family: nftables.TableFamilyIPv4,
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Name: "filter",
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})
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forward := c.AddChain(&nftables.Chain{
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Name: "forward",
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Table: filter,
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Type: nftables.ChainTypeFilter,
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Hooknum: nftables.ChainHookForward,
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Priority: nftables.ChainPriorityFilter,
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})
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c.AddRule(&nftables.Rule{
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Table: filter,
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Chain: forward,
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Exprs: []expr.Any{
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// [ meta load l4proto => reg 1 ]
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&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 1},
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// [ cmp eq reg 1 0x00000006 ]
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&expr.Cmp{
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Op: expr.CmpOpEq,
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Register: 1,
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Data: []byte{unix.IPPROTO_TCP},
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},
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// [ payload load 2b @ transport header + 0 => reg 1 ]
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&expr.Payload{
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DestRegister: 1,
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Base: expr.PayloadBaseTransportHeader,
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Offset: 0, // TODO
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Len: 2, // TODO
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},
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// [ range neq reg 1 0x0000e807 0x0000ee07 ]
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&expr.Range{
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Op: expr.CmpOpNeq,
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Register: 1,
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FromData: binaryutil.BigEndian.PutUint16(uint16(2024)),
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ToData: binaryutil.BigEndian.PutUint16(uint16(2030)),
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},
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// [ immediate reg 0 return ]
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&expr.Verdict{
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Kind: expr.VerdictKind(unix.NFT_RETURN),
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},
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},
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})
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if err := c.Flush(); err != nil {
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t.Fatal(err)
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}
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}
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func TestConfigureRangeIPv4(t *testing.T) {
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// The want byte sequences come from stracing nft(8), e.g.:
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// strace -f -v -x -s 2048 -eraw=sendto nft add rule filter forward ip saddr != 192.168.1.0-192.168.2.0 return
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//
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// The nft(8) command sequence was taken from:
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// https://wiki.nftables.org/wiki-nftables/index.php/Quick_reference-nftables_in_10_minutes#Tcp
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want := [][]byte{
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// batch begin
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[]byte("\x00\x00\x00\x0a"),
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// nft flush ruleset
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[]byte("\x00\x00\x00\x00"),
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// nft add table ip filter
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[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x08\x00\x02\x00\x00\x00\x00\x00"),
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// nft add chain filter forward '{' type filter hook forward priority 0 \; '}'
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[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0c\x00\x03\x00\x66\x6f\x72\x77\x61\x72\x64\x00\x14\x00\x04\x80\x08\x00\x01\x00\x00\x00\x00\x02\x08\x00\x02\x00\x00\x00\x00\x00\x0b\x00\x07\x00\x66\x69\x6c\x74\x65\x72\x00\x00"),
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// nft add rule filter forward ip saddr != 192.168.1.0-192.168.2.0 return
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[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0c\x00\x02\x00\x66\x6f\x72\x77\x61\x72\x64\x00\xa4\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\x0c\x08\x00\x04\x00\x00\x00\x00\x04\x3c\x00\x01\x80\x0a\x00\x01\x00\x72\x61\x6e\x67\x65\x00\x00\x00\x2c\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x08\x00\x02\x00\x00\x00\x00\x01\x0c\x00\x03\x80\x08\x00\x01\x00\xc0\xa8\x01\x00\x0c\x00\x04\x80\x08\x00\x01\x00\xc0\xa8\x02\x00\x30\x00\x01\x80\x0e\x00\x01\x00\x69\x6d\x6d\x65\x64\x69\x61\x74\x65\x00\x00\x00\x1c\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x00\x10\x00\x02\x80\x0c\x00\x02\x80\x08\x00\x01\x00\xff\xff\xff\xfb"),
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// batch end
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[]byte("\x00\x00\x00\x0a"),
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}
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c := &nftables.Conn{
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TestDial: func(req []netlink.Message) ([]netlink.Message, error) {
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for idx, msg := range req {
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b, err := msg.MarshalBinary()
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if err != nil {
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t.Fatal(err)
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}
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if len(b) < 16 {
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continue
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}
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b = b[16:]
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if len(want) == 0 {
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t.Errorf("no want entry for message %d: %x", idx, b)
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continue
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}
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if got, want := b, want[0]; !bytes.Equal(got, want) {
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t.Errorf("message %d: %s", idx, linediff(nfdump(got), nfdump(want)))
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}
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want = want[1:]
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}
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return req, nil
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},
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}
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c.FlushRuleset()
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filter := c.AddTable(&nftables.Table{
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Family: nftables.TableFamilyIPv4,
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Name: "filter",
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})
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forward := c.AddChain(&nftables.Chain{
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Name: "forward",
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Table: filter,
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Type: nftables.ChainTypeFilter,
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Hooknum: nftables.ChainHookForward,
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Priority: nftables.ChainPriorityFilter,
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})
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c.AddRule(&nftables.Rule{
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Table: filter,
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Chain: forward,
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Exprs: []expr.Any{
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// [ payload load 4b @ network header + 12 => reg 1 ]
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&expr.Payload{
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DestRegister: 1,
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Base: expr.PayloadBaseNetworkHeader,
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Offset: 12, // TODO
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Len: 4, // TODO
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},
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// [ range neq reg 1 0x0000e807 0x0000ee07 ]
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&expr.Range{
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Op: expr.CmpOpNeq,
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Register: 1,
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FromData: net.ParseIP("192.168.1.0").To4(),
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ToData: net.ParseIP("192.168.2.0").To4(),
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},
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// [ immediate reg 0 return ]
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&expr.Verdict{
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Kind: expr.VerdictKind(unix.NFT_RETURN),
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},
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},
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})
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if err := c.Flush(); err != nil {
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t.Fatal(err)
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}
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}
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func TestConfigureRangeIPv6(t *testing.T) {
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// The want byte sequences come from stracing nft(8), e.g.:
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// strace -f -v -x -s 2048 -eraw=sendto nft add rule ip6 filter forward ip6 saddr != 2001:0001::1-2001:0002::1 return
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//
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// The nft(8) command sequence was taken from:
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// https://wiki.nftables.org/wiki-nftables/index.php/Quick_reference-nftables_in_10_minutes#Tcp
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want := [][]byte{
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// batch begin
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[]byte("\x00\x00\x00\x0a"),
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// nft flush ruleset
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[]byte("\x00\x00\x00\x00"),
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// nft add table ip6 filter
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[]byte("\x0a\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x08\x00\x02\x00\x00\x00\x00\x00"),
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// nft add chain ip6 filter forward '{' type filter hook forward priority 0 \; '}'
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[]byte("\x0a\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0c\x00\x03\x00\x66\x6f\x72\x77\x61\x72\x64\x00\x14\x00\x04\x80\x08\x00\x01\x00\x00\x00\x00\x02\x08\x00\x02\x00\x00\x00\x00\x00\x0b\x00\x07\x00\x66\x69\x6c\x74\x65\x72\x00\x00"),
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// nft add rule ip6 filter forward ip6 saddr != 2001:0001::1-2001:0002::1 return
|
||||
[]byte("\x0a\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0c\x00\x02\x00\x66\x6f\x72\x77\x61\x72\x64\x00\xbc\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\x08\x08\x00\x04\x00\x00\x00\x00\x10\x54\x00\x01\x80\x0a\x00\x01\x00\x72\x61\x6e\x67\x65\x00\x00\x00\x44\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x08\x00\x02\x00\x00\x00\x00\x01\x18\x00\x03\x80\x14\x00\x01\x00\x20\x01\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x18\x00\x04\x80\x14\x00\x01\x00\x20\x01\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x30\x00\x01\x80\x0e\x00\x01\x00\x69\x6d\x6d\x65\x64\x69\x61\x74\x65\x00\x00\x00\x1c\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x00\x10\x00\x02\x80\x0c\x00\x02\x80\x08\x00\x01\x00\xff\xff\xff\xfb"),
|
||||
// batch end
|
||||
[]byte("\x00\x00\x00\x0a"),
|
||||
}
|
||||
|
||||
c := &nftables.Conn{
|
||||
TestDial: 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
|
||||
},
|
||||
}
|
||||
|
||||
c.FlushRuleset()
|
||||
|
||||
filter := c.AddTable(&nftables.Table{
|
||||
Family: nftables.TableFamilyIPv6,
|
||||
Name: "filter",
|
||||
})
|
||||
|
||||
forward := c.AddChain(&nftables.Chain{
|
||||
Name: "forward",
|
||||
Table: filter,
|
||||
Type: nftables.ChainTypeFilter,
|
||||
Hooknum: nftables.ChainHookForward,
|
||||
Priority: nftables.ChainPriorityFilter,
|
||||
})
|
||||
|
||||
ip1 := net.ParseIP("2001:0001::1").To16()
|
||||
ip2 := net.ParseIP("2001:0002::1").To16()
|
||||
|
||||
c.AddRule(&nftables.Rule{
|
||||
Table: filter,
|
||||
Chain: forward,
|
||||
Exprs: []expr.Any{
|
||||
// [ payload load 16b @ network header + 8 => reg 1 ]
|
||||
&expr.Payload{
|
||||
DestRegister: 1,
|
||||
Base: expr.PayloadBaseNetworkHeader,
|
||||
Offset: 8, // TODO
|
||||
Len: 16, // TODO
|
||||
},
|
||||
// [ range neq reg 1 0x01000120 0x00000000 0x00000000 0x01000000 0x02000120 0x00000000 0x00000000 0x01000000 ]
|
||||
&expr.Range{
|
||||
Op: expr.CmpOpNeq,
|
||||
Register: 1,
|
||||
FromData: ip1,
|
||||
ToData: ip2,
|
||||
},
|
||||
// [ immediate reg 0 return ]
|
||||
&expr.Verdict{
|
||||
Kind: expr.VerdictKind(unix.NFT_RETURN),
|
||||
},
|
||||
},
|
||||
})
|
||||
|
||||
if err := c.Flush(); err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue