nftables/expr/connlimit.go

75 lines
2.1 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"
)
const (
// Per https://git.netfilter.org/libnftnl/tree/include/linux/netfilter/nf_tables.h?id=84d12cfacf8ddd857a09435f3d982ab6250d250c#n1167
NFTA_CONNLIMIT_UNSPEC = iota
NFTA_CONNLIMIT_COUNT
NFTA_CONNLIMIT_FLAGS
NFT_CONNLIMIT_F_INV = 1
)
// Per https://git.netfilter.org/libnftnl/tree/src/expr/connlimit.c?id=84d12cfacf8ddd857a09435f3d982ab6250d250c
type Connlimit struct {
Count uint32
Flags uint32
}
func (e *Connlimit) 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("connlimit\x00")},
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: data},
})
}
func (e *Connlimit) marshalData(fam byte) ([]byte, error) {
return netlink.MarshalAttributes([]netlink.Attribute{
{Type: NFTA_CONNLIMIT_COUNT, Data: binaryutil.BigEndian.PutUint32(e.Count)},
{Type: NFTA_CONNLIMIT_FLAGS, Data: binaryutil.BigEndian.PutUint32(e.Flags)},
})
}
func (e *Connlimit) 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_CONNLIMIT_COUNT:
e.Count = binaryutil.BigEndian.Uint32(ad.Bytes())
case NFTA_CONNLIMIT_FLAGS:
e.Flags = binaryutil.BigEndian.Uint32(ad.Bytes())
}
}
return ad.Err()
}