Reject expression and Unit tests (#53)

This commit is contained in:
Serguei Bezverkhi 2019-08-26 03:57:52 -04:00 committed by Michael Stapelberg
parent ec0390b058
commit d514535a0c
2 changed files with 174 additions and 0 deletions

59
expr/reject.go Normal file
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@ -0,0 +1,59 @@
// Copyright 2018 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 expr
import (
"encoding/binary"
"github.com/google/nftables/binaryutil"
"github.com/mdlayher/netlink"
"golang.org/x/sys/unix"
)
type Reject struct {
Type uint32
Code uint8
}
func (e *Reject) marshal() ([]byte, error) {
data, err := netlink.MarshalAttributes([]netlink.Attribute{
{Type: unix.NFTA_REJECT_TYPE, Data: binaryutil.BigEndian.PutUint32(e.Type)},
{Type: unix.NFTA_REJECT_ICMP_CODE, Data: []byte{e.Code}},
})
if err != nil {
return nil, err
}
return netlink.MarshalAttributes([]netlink.Attribute{
{Type: unix.NFTA_EXPR_NAME, Data: []byte("reject\x00")},
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: data},
})
}
func (e *Reject) unmarshal(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_REJECT_TYPE:
e.Type = ad.Uint32()
case unix.NFTA_REJECT_ICMP_CODE:
e.Code = ad.Uint8()
}
}
return ad.Err()
}

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@ -2541,3 +2541,118 @@ func TestMasq(t *testing.T) {
}
}
}
func TestReject(t *testing.T) {
tests := []struct {
name string
chain *nftables.Chain
want [][]byte
rejectExprs []expr.Any
}{
{
name: "Reject",
chain: &nftables.Chain{
Name: "base-chain",
},
want: [][]byte{
// batch begin
[]byte("\x00\x00\x00\x0a"),
// nft add table ip filter
[]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"),
// nft add chain ip filter base-chain
[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0f\x00\x03\x00\x62\x61\x73\x65\x2d\x63\x68\x61\x69\x6e\x00\x00"),
// nft add rule ip filter base-chain reject
[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0f\x00\x02\x00\x62\x61\x73\x65\x2d\x63\x68\x61\x69\x6e\x00\x00\x28\x00\x04\x80\x24\x00\x01\x80\x0b\x00\x01\x00\x72\x65\x6a\x65\x63\x74\x00\x00\x14\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x00\x05\x00\x02\x00\x00\x00\x00\x00"),
// batch end
[]byte("\x00\x00\x00\x0a"),
},
rejectExprs: []expr.Any{
&expr.Reject{},
},
},
{
name: "Reject with tcp reset",
chain: &nftables.Chain{
Name: "base-chain",
},
want: [][]byte{
// batch begin
[]byte("\x00\x00\x00\x0a"),
// nft add table ip filter
[]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"),
// nft add chain ip filter base-chain
[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0f\x00\x03\x00\x62\x61\x73\x65\x2d\x63\x68\x61\x69\x6e\x00\x00"),
// nft add rule ip filter base-chain reject with tcp reset
[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0f\x00\x02\x00\x62\x61\x73\x65\x2d\x63\x68\x61\x69\x6e\x00\x00\x28\x00\x04\x80\x24\x00\x01\x80\x0b\x00\x01\x00\x72\x65\x6a\x65\x63\x74\x00\x00\x14\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x05\x00\x02\x00\x01\x00\x00\x00"),
// batch end
[]byte("\x00\x00\x00\x0a"),
},
rejectExprs: []expr.Any{
&expr.Reject{Type: unix.NFT_REJECT_TCP_RST, Code: unix.NFT_REJECT_TCP_RST},
},
},
{
name: "Reject with icmp type host-unreachable",
chain: &nftables.Chain{
Name: "base-chain",
},
want: [][]byte{
// batch begin
[]byte("\x00\x00\x00\x0a"),
// nft add table ip filter
[]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"),
// nft add chain ip filter base-chain
[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0f\x00\x03\x00\x62\x61\x73\x65\x2d\x63\x68\x61\x69\x6e\x00\x00"),
// nft add rule ip filter base-chain reject with icmp type host-unreachable
[]byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0f\x00\x02\x00\x62\x61\x73\x65\x2d\x63\x68\x61\x69\x6e\x00\x00\x28\x00\x04\x80\x24\x00\x01\x80\x0b\x00\x01\x00\x72\x65\x6a\x65\x63\x74\x00\x00\x14\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x00\x05\x00\x02\x00\x00\x00\x00\x00"),
// batch end
[]byte("\x00\x00\x00\x0a"),
},
rejectExprs: []expr.Any{
&expr.Reject{Type: unix.NFT_REJECT_ICMP_UNREACH, Code: unix.NFT_REJECT_ICMP_UNREACH},
},
},
}
for _, tt := range tests {
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(tt.want[idx]) == 0 {
t.Errorf("no want entry for message %d: %x", idx, b)
continue
}
got := b
if !bytes.Equal(got, tt.want[idx]) {
t.Errorf("message %d: %s", idx, linediff(nfdump(got), nfdump(tt.want[idx])))
}
}
return req, nil
},
}
filter := c.AddTable(&nftables.Table{
Family: nftables.TableFamilyIPv4,
Name: "filter",
})
tt.chain.Table = filter
chain := c.AddChain(tt.chain)
c.AddRule(&nftables.Rule{
Table: filter,
Chain: chain,
Exprs: tt.rejectExprs,
})
if err := c.Flush(); err != nil {
t.Fatalf("Test \"%s\" failed with error: %+v", tt.name, err)
}
}
}