133 lines
3.4 KiB
Go
133 lines
3.4 KiB
Go
// Copyright 2019 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"
|
|
)
|
|
|
|
// Range implements range expression
|
|
type Range struct {
|
|
Op CmpOp
|
|
Register uint32
|
|
FromData []byte
|
|
ToData []byte
|
|
}
|
|
|
|
func (e *Range) marshal(fam byte) ([]byte, error) {
|
|
data, err := e.marshalData(fam)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return netlink.MarshalAttributes([]netlink.Attribute{
|
|
{Type: unix.NFTA_EXPR_NAME, Data: []byte("range\x00")},
|
|
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: data},
|
|
})
|
|
}
|
|
|
|
func (e *Range) marshalData(fam byte) ([]byte, error) {
|
|
var attrs []netlink.Attribute
|
|
var err error
|
|
var rangeFromData, rangeToData []byte
|
|
|
|
if e.Register > 0 {
|
|
attrs = append(attrs, netlink.Attribute{Type: unix.NFTA_RANGE_SREG, Data: binaryutil.BigEndian.PutUint32(e.Register)})
|
|
}
|
|
attrs = append(attrs, netlink.Attribute{Type: unix.NFTA_RANGE_OP, Data: binaryutil.BigEndian.PutUint32(uint32(e.Op))})
|
|
if len(e.FromData) > 0 {
|
|
rangeFromData, err = nestedAttr(e.FromData, unix.NFTA_RANGE_FROM_DATA)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
if len(e.ToData) > 0 {
|
|
rangeToData, err = nestedAttr(e.ToData, unix.NFTA_RANGE_TO_DATA)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
data, err := netlink.MarshalAttributes(attrs)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
data = append(data, rangeFromData...)
|
|
data = append(data, rangeToData...)
|
|
return data, nil
|
|
}
|
|
|
|
func (e *Range) 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_RANGE_OP:
|
|
e.Op = CmpOp(ad.Uint32())
|
|
case unix.NFTA_RANGE_SREG:
|
|
e.Register = ad.Uint32()
|
|
case unix.NFTA_RANGE_FROM_DATA:
|
|
ad.Do(func(b []byte) error {
|
|
ad, err := netlink.NewAttributeDecoder(b)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
ad.ByteOrder = binary.BigEndian
|
|
if ad.Next() && ad.Type() == unix.NFTA_DATA_VALUE {
|
|
ad.Do(func(b []byte) error {
|
|
e.FromData = b
|
|
return nil
|
|
})
|
|
}
|
|
return ad.Err()
|
|
})
|
|
case unix.NFTA_RANGE_TO_DATA:
|
|
ad.Do(func(b []byte) error {
|
|
ad, err := netlink.NewAttributeDecoder(b)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
ad.ByteOrder = binary.BigEndian
|
|
if ad.Next() && ad.Type() == unix.NFTA_DATA_VALUE {
|
|
ad.Do(func(b []byte) error {
|
|
e.ToData = b
|
|
return nil
|
|
})
|
|
}
|
|
return ad.Err()
|
|
})
|
|
}
|
|
}
|
|
return ad.Err()
|
|
}
|
|
|
|
func nestedAttr(data []byte, attrType uint16) ([]byte, error) {
|
|
ae := netlink.NewAttributeEncoder()
|
|
ae.Do(unix.NLA_F_NESTED|attrType, func() ([]byte, error) {
|
|
nae := netlink.NewAttributeEncoder()
|
|
nae.ByteOrder = binary.BigEndian
|
|
nae.Bytes(unix.NFTA_DATA_VALUE, data)
|
|
|
|
return nae.Encode()
|
|
})
|
|
return ae.Encode()
|
|
}
|