nftables/expr/exthdr.go

65 lines
2.0 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 (
"fmt"
"github.com/google/nftables/binaryutil"
"github.com/mdlayher/netlink"
"golang.org/x/sys/unix"
)
type ExthdrOp uint32
const (
ExthdrOpIpv6 ExthdrOp = unix.NFT_EXTHDR_OP_IPV6
ExthdrOpTcpopt ExthdrOp = unix.NFT_EXTHDR_OP_TCPOPT
)
type Exthdr struct {
DestRegister uint32
Type uint8
Offset uint32
Len uint32
Flags uint32
Op ExthdrOp
SourceRegister uint32
}
func (e *Exthdr) marshal() ([]byte, error) {
data, err := netlink.MarshalAttributes([]netlink.Attribute{
{Type: unix.NFTA_EXTHDR_SREG, Data: binaryutil.BigEndian.PutUint32(e.SourceRegister)},
{Type: unix.NFTA_EXTHDR_TYPE, Data: []byte{e.Type}},
{Type: unix.NFTA_EXTHDR_OFFSET, Data: binaryutil.BigEndian.PutUint32(e.Offset)},
{Type: unix.NFTA_EXTHDR_LEN, Data: binaryutil.BigEndian.PutUint32(e.Len)},
// TODO: these fields seem to be conditional?
//{Type: unix.NFTA_EXTHDR_DREG, Data: binaryutil.BigEndian.PutUint32(e.DestRegister)},
//{Type: unix.NFTA_EXTHDR_FLAGS, Data: binaryutil.BigEndian.PutUint32(e.Flags)},
{Type: unix.NFTA_EXTHDR_OP, Data: binaryutil.BigEndian.PutUint32(uint32(e.Op))},
})
if err != nil {
return nil, err
}
return netlink.MarshalAttributes([]netlink.Attribute{
{Type: unix.NFTA_EXPR_NAME, Data: []byte("exthdr\x00")},
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: data},
})
}
func (e *Exthdr) unmarshal(data []byte) error {
return fmt.Errorf("not yet implemented")
}