90 lines
2.5 KiB
Go
90 lines
2.5 KiB
Go
|
// Copyright 2023 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"
|
||
|
|
|
||
|
|
"golang.org/x/sys/unix"
|
||
|
|
|
||
|
|
"github.com/google/nftables/binaryutil"
|
||
|
|
"github.com/mdlayher/netlink"
|
||
|
|
)
|
||
|
|
|
||
|
|
type Socket struct {
|
||
|
|
Key SocketKey
|
||
|
|
Level uint32
|
||
|
|
Register uint32
|
||
|
|
}
|
||
|
|
|
||
|
|
type SocketKey uint32
|
||
|
|
|
||
|
|
const (
|
||
|
|
// TODO, Once the constants below are available in golang.org/x/sys/unix, switch to use those.
|
||
|
|
NFTA_SOCKET_KEY = 1
|
||
|
|
NFTA_SOCKET_DREG = 2
|
||
|
|
NFTA_SOCKET_LEVEL = 3
|
||
|
|
|
||
|
|
NFT_SOCKET_TRANSPARENT = 0
|
||
|
|
NFT_SOCKET_MARK = 1
|
||
|
|
NFT_SOCKET_WILDCARD = 2
|
||
|
|
NFT_SOCKET_CGROUPV2 = 3
|
||
|
|
|
||
|
|
SocketKeyTransparent SocketKey = NFT_SOCKET_TRANSPARENT
|
||
|
|
SocketKeyMark SocketKey = NFT_SOCKET_MARK
|
||
|
|
SocketKeyWildcard SocketKey = NFT_SOCKET_WILDCARD
|
||
|
|
SocketKeyCgroupv2 SocketKey = NFT_SOCKET_CGROUPV2
|
||
|
|
)
|
||
|
|
|
||
|
|
func (e *Socket) marshal(fam byte) ([]byte, error) {
|
||
|
|
// NOTE: Socket.Level is only used when Socket.Key == SocketKeyCgroupv2. But `nft` always encoding it. Check link below:
|
||
|
|
// http://git.netfilter.org/nftables/tree/src/netlink_linearize.c?id=0583bac241ea18c9d7f61cb20ca04faa1e043b78#n319
|
||
|
|
exprData, err := netlink.MarshalAttributes(
|
||
|
|
[]netlink.Attribute{
|
||
|
|
{Type: NFTA_SOCKET_DREG, Data: binaryutil.BigEndian.PutUint32(e.Register)},
|
||
|
|
{Type: NFTA_SOCKET_KEY, Data: binaryutil.BigEndian.PutUint32(uint32(e.Key))},
|
||
|
|
{Type: NFTA_SOCKET_LEVEL, Data: binaryutil.BigEndian.PutUint32(uint32(e.Level))},
|
||
|
|
},
|
||
|
|
)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
return netlink.MarshalAttributes([]netlink.Attribute{
|
||
|
|
{Type: unix.NFTA_EXPR_NAME, Data: []byte("socket\x00")},
|
||
|
|
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: exprData},
|
||
|
|
})
|
||
|
|
}
|
||
|
|
|
||
|
|
func (e *Socket) 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 NFTA_SOCKET_DREG:
|
||
|
|
e.Register = ad.Uint32()
|
||
|
|
case NFTA_SOCKET_KEY:
|
||
|
|
e.Key = SocketKey(ad.Uint32())
|
||
|
|
case NFTA_SOCKET_LEVEL:
|
||
|
|
e.Level = ad.Uint32()
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return ad.Err()
|
||
|
|
}
|