nftables/expr/fib.go

136 lines
3.5 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"
)
// Fib defines fib expression structure
type Fib struct {
Register uint32
ResultOIF bool
ResultOIFNAME bool
ResultADDRTYPE bool
FlagSADDR bool
FlagDADDR bool
FlagMARK bool
FlagIIF bool
FlagOIF bool
FlagPRESENT bool
}
func (e *Fib) 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("fib\x00")},
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: data},
})
}
func (e *Fib) marshalData(fam byte) ([]byte, error) {
data := []byte{}
reg, err := netlink.MarshalAttributes([]netlink.Attribute{
{Type: unix.NFTA_FIB_DREG, Data: binaryutil.BigEndian.PutUint32(e.Register)},
})
if err != nil {
return nil, err
}
data = append(data, reg...)
flags := uint32(0)
if e.FlagSADDR {
flags |= unix.NFTA_FIB_F_SADDR
}
if e.FlagDADDR {
flags |= unix.NFTA_FIB_F_DADDR
}
if e.FlagMARK {
flags |= unix.NFTA_FIB_F_MARK
}
if e.FlagIIF {
flags |= unix.NFTA_FIB_F_IIF
}
if e.FlagOIF {
flags |= unix.NFTA_FIB_F_OIF
}
if e.FlagPRESENT {
flags |= unix.NFTA_FIB_F_PRESENT
}
if flags != 0 {
flg, err := netlink.MarshalAttributes([]netlink.Attribute{
{Type: unix.NFTA_FIB_FLAGS, Data: binaryutil.BigEndian.PutUint32(flags)},
})
if err != nil {
return nil, err
}
data = append(data, flg...)
}
results := uint32(0)
if e.ResultOIF {
results |= unix.NFT_FIB_RESULT_OIF
}
if e.ResultOIFNAME {
results |= unix.NFT_FIB_RESULT_OIFNAME
}
if e.ResultADDRTYPE {
results |= unix.NFT_FIB_RESULT_ADDRTYPE
}
if results != 0 {
rslt, err := netlink.MarshalAttributes([]netlink.Attribute{
{Type: unix.NFTA_FIB_RESULT, Data: binaryutil.BigEndian.PutUint32(results)},
})
if err != nil {
return nil, err
}
data = append(data, rslt...)
}
return data, nil
}
func (e *Fib) 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_FIB_DREG:
e.Register = ad.Uint32()
case unix.NFTA_FIB_RESULT:
result := ad.Uint32()
e.ResultOIF = (result & unix.NFT_FIB_RESULT_OIF) == 1
e.ResultOIFNAME = (result & unix.NFT_FIB_RESULT_OIFNAME) == 1
e.ResultADDRTYPE = (result & unix.NFT_FIB_RESULT_ADDRTYPE) == 1
case unix.NFTA_FIB_FLAGS:
flags := ad.Uint32()
e.FlagSADDR = (flags & unix.NFTA_FIB_F_SADDR) == 1
e.FlagDADDR = (flags & unix.NFTA_FIB_F_DADDR) == 1
e.FlagMARK = (flags & unix.NFTA_FIB_F_MARK) == 1
e.FlagIIF = (flags & unix.NFTA_FIB_F_IIF) == 1
e.FlagOIF = (flags & unix.NFTA_FIB_F_OIF) == 1
e.FlagPRESENT = (flags & unix.NFTA_FIB_F_PRESENT) == 1
}
}
return ad.Err()
}