nftables/expr/lookup.go

61 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"
)
// Lookup represents a match against the contents of a set.
type Lookup struct {
SourceRegister uint32
DestRegister uint32
SetID uint32
SetName string
}
func (e *Lookup) marshal() ([]byte, error) {
// See: https://git.netfilter.org/libnftnl/tree/src/expr/lookup.c?id=6dc1c3d8bb64077da7f3f28c7368fb087d10a492#n115
var opAttrs []netlink.Attribute
if e.SourceRegister != 0 {
opAttrs = append(opAttrs, netlink.Attribute{Type: unix.NFTA_LOOKUP_SREG, Data: binaryutil.BigEndian.PutUint32(e.SourceRegister)})
}
if e.DestRegister != 0 {
opAttrs = append(opAttrs, netlink.Attribute{Type: unix.NFTA_LOOKUP_DREG, Data: binaryutil.BigEndian.PutUint32(e.DestRegister)})
}
opAttrs = append(opAttrs,
netlink.Attribute{Type: unix.NFTA_LOOKUP_SET, Data: []byte(e.SetName + "\x00")},
netlink.Attribute{Type: unix.NFTA_LOOKUP_SET_ID, Data: binaryutil.BigEndian.PutUint32(e.SetID)},
)
opData, err := netlink.MarshalAttributes(opAttrs)
if err != nil {
return nil, err
}
return netlink.MarshalAttributes([]netlink.Attribute{
{Type: unix.NFTA_EXPR_NAME, Data: []byte("lookup\x00")},
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: opData},
})
}
func (e *Lookup) unmarshal(data []byte) error {
return fmt.Errorf("not yet implemented")
}