nftables/expr/quota.go

81 lines
2.1 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"
)
// Quota defines a threshold against a number of bytes.
type Quota struct {
Bytes uint64
Consumed uint64
Over bool
}
func (q *Quota) marshal(fam byte) ([]byte, error) {
data, err := q.marshalData(fam)
if err != nil {
return nil, err
}
return netlink.MarshalAttributes([]netlink.Attribute{
{Type: unix.NFTA_EXPR_NAME, Data: []byte("quota\x00")},
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: data},
})
}
func (q *Quota) marshalData(fam byte) ([]byte, error) {
attrs := []netlink.Attribute{
{Type: unix.NFTA_QUOTA_BYTES, Data: binaryutil.BigEndian.PutUint64(q.Bytes)},
{Type: unix.NFTA_QUOTA_CONSUMED, Data: binaryutil.BigEndian.PutUint64(q.Consumed)},
}
flags := uint32(0)
if q.Over {
flags = unix.NFT_QUOTA_F_INV
}
attrs = append(attrs, netlink.Attribute{
Type: unix.NFTA_QUOTA_FLAGS,
Data: binaryutil.BigEndian.PutUint32(flags),
})
return netlink.MarshalAttributes(attrs)
}
func (q *Quota) 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_QUOTA_BYTES:
q.Bytes = ad.Uint64()
case unix.NFTA_QUOTA_CONSUMED:
q.Consumed = ad.Uint64()
case unix.NFTA_QUOTA_FLAGS:
q.Over = (ad.Uint32() & unix.NFT_QUOTA_F_INV) == 1
}
}
return ad.Err()
}