69 lines
1.9 KiB
Go
69 lines
1.9 KiB
Go
// 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"
|
|
)
|
|
|
|
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
|
|
)
|
|
|
|
// TProxy defines struct with parameters for the transparent proxy
|
|
type TProxy struct {
|
|
Family byte
|
|
TableFamily byte
|
|
RegPort uint32
|
|
}
|
|
|
|
func (e *TProxy) marshal() ([]byte, error) {
|
|
data, err := netlink.MarshalAttributes([]netlink.Attribute{
|
|
{Type: NFTA_TPROXY_FAMILY, Data: binaryutil.BigEndian.PutUint32(uint32(e.Family))},
|
|
{Type: NFTA_TPROXY_REG, Data: binaryutil.BigEndian.PutUint32(e.RegPort)},
|
|
})
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return netlink.MarshalAttributes([]netlink.Attribute{
|
|
{Type: unix.NFTA_EXPR_NAME, Data: []byte("tproxy\x00")},
|
|
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: data},
|
|
})
|
|
}
|
|
|
|
func (e *TProxy) 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 NFTA_TPROXY_FAMILY:
|
|
e.Family = ad.Uint8()
|
|
case NFTA_TPROXY_REG:
|
|
e.RegPort = ad.Uint32()
|
|
}
|
|
}
|
|
return ad.Err()
|
|
}
|