diff --git a/expr/queue.go b/expr/queue.go new file mode 100644 index 0000000..9008ab5 --- /dev/null +++ b/expr/queue.go @@ -0,0 +1,82 @@ +// 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" +) + +type QueueAttribute uint16 + +type QueueFlag uint16 + +// Possible QueueAttribute values +const ( + QueueNum QueueAttribute = unix.NFTA_QUEUE_NUM + QueueTotal QueueAttribute = unix.NFTA_QUEUE_TOTAL + QueueFlags QueueAttribute = unix.NFTA_QUEUE_FLAGS + + // TODO: get into x/sys/unix + QueueFlagBypass QueueFlag = 0x01 + QueueFlagFanout QueueFlag = 0x02 + QueueFlagMask QueueFlag = 0x03 +) + +type Queue struct { + Num uint16 + Total uint16 + Flag QueueFlag +} + +func (e *Queue) marshal() ([]byte, error) { + if e.Total == 0 { + e.Total = 1 // The total default value is 1 + } + data, err := netlink.MarshalAttributes([]netlink.Attribute{ + {Type: unix.NFTA_QUEUE_NUM, Data: binaryutil.BigEndian.PutUint16(e.Num)}, + {Type: unix.NFTA_QUEUE_TOTAL, Data: binaryutil.BigEndian.PutUint16(e.Total)}, + {Type: unix.NFTA_QUEUE_FLAGS, Data: binaryutil.BigEndian.PutUint16(uint16(e.Flag))}, + }) + if err != nil { + return nil, err + } + return netlink.MarshalAttributes([]netlink.Attribute{ + {Type: unix.NFTA_EXPR_NAME, Data: []byte("queue\x00")}, + {Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: data}, + }) +} + +func (e *Queue) unmarshal(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_QUEUE_NUM: + e.Num = ad.Uint16() + case unix.NFTA_QUEUE_TOTAL: + e.Total = ad.Uint16() + case unix.NFTA_QUEUE_FLAGS: + e.Flag = QueueFlag(ad.Uint16()) + } + } + return ad.Err() +}