Matteo Scandolo | 4b3fc7e | 2019-09-17 16:49:54 -0700 | [diff] [blame] | 1 | /* |
Joey Armstrong | 14628cd | 2023-01-10 08:38:31 -0500 | [diff] [blame^] | 2 | * Copyright 2018-2023 Open Networking Foundation (ONF) and the ONF Contributors |
Matteo Scandolo | 4b3fc7e | 2019-09-17 16:49:54 -0700 | [diff] [blame] | 3 | |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package packetHandlers |
| 18 | |
| 19 | import ( |
| 20 | "errors" |
Shrey Baid | 688b424 | 2020-07-10 20:40:10 +0530 | [diff] [blame] | 21 | |
Matteo Scandolo | 4b3fc7e | 2019-09-17 16:49:54 -0700 | [diff] [blame] | 22 | "github.com/google/gopacket" |
| 23 | "github.com/google/gopacket/layers" |
| 24 | ) |
| 25 | |
Matteo Scandolo | 8d28137 | 2020-09-03 16:23:37 -0700 | [diff] [blame] | 26 | func PushSingleTag(tag int, pkt gopacket.Packet, pbit uint8) (gopacket.Packet, error) { |
Matteo Scandolo | 4b3fc7e | 2019-09-17 16:49:54 -0700 | [diff] [blame] | 27 | // TODO can this method be semplified? |
| 28 | if eth := getEthernetLayer(pkt); eth != nil { |
| 29 | ethernetLayer := &layers.Ethernet{ |
| 30 | SrcMAC: eth.SrcMAC, |
| 31 | DstMAC: eth.DstMAC, |
| 32 | EthernetType: 0x8100, |
| 33 | } |
| 34 | |
| 35 | dot1qLayer := &layers.Dot1Q{ |
| 36 | Type: eth.EthernetType, |
| 37 | VLANIdentifier: uint16(tag), |
Matteo Scandolo | 8d28137 | 2020-09-03 16:23:37 -0700 | [diff] [blame] | 38 | Priority: pbit, |
Matteo Scandolo | 4b3fc7e | 2019-09-17 16:49:54 -0700 | [diff] [blame] | 39 | } |
| 40 | |
| 41 | buffer := gopacket.NewSerializeBuffer() |
Shrey Baid | 688b424 | 2020-07-10 20:40:10 +0530 | [diff] [blame] | 42 | _ = gopacket.SerializeLayers( |
Matteo Scandolo | 4b3fc7e | 2019-09-17 16:49:54 -0700 | [diff] [blame] | 43 | buffer, |
| 44 | gopacket.SerializeOptions{ |
| 45 | FixLengths: false, |
| 46 | }, |
| 47 | ethernetLayer, |
| 48 | dot1qLayer, |
| 49 | gopacket.Payload(eth.Payload), |
| 50 | ) |
| 51 | ret := gopacket.NewPacket( |
| 52 | buffer.Bytes(), |
| 53 | layers.LayerTypeEthernet, |
| 54 | gopacket.Default, |
| 55 | ) |
| 56 | |
| 57 | return ret, nil |
| 58 | } |
| 59 | return nil, errors.New("Couldn't extract LayerTypeEthernet from packet") |
| 60 | } |
| 61 | |
Matteo Scandolo | 8d28137 | 2020-09-03 16:23:37 -0700 | [diff] [blame] | 62 | func PushDoubleTag(stag int, ctag int, pkt gopacket.Packet, pbit uint8) (gopacket.Packet, error) { |
Matteo Scandolo | f6f3a7f | 2019-10-11 11:19:29 -0700 | [diff] [blame] | 63 | |
Matteo Scandolo | 8d28137 | 2020-09-03 16:23:37 -0700 | [diff] [blame] | 64 | singleTaggedPkt, err := PushSingleTag(ctag, pkt, pbit) |
Matteo Scandolo | f6f3a7f | 2019-10-11 11:19:29 -0700 | [diff] [blame] | 65 | if err != nil { |
| 66 | return nil, err |
| 67 | } |
Matteo Scandolo | 8d28137 | 2020-09-03 16:23:37 -0700 | [diff] [blame] | 68 | doubleTaggedPkt, err := PushSingleTag(stag, singleTaggedPkt, pbit) |
Matteo Scandolo | f6f3a7f | 2019-10-11 11:19:29 -0700 | [diff] [blame] | 69 | if err != nil { |
| 70 | return nil, err |
| 71 | } |
| 72 | |
| 73 | return doubleTaggedPkt, nil |
| 74 | } |
| 75 | |
Matteo Scandolo | 4b3fc7e | 2019-09-17 16:49:54 -0700 | [diff] [blame] | 76 | func PopSingleTag(pkt gopacket.Packet) (gopacket.Packet, error) { |
| 77 | layer, err := getDot1QLayer(pkt) |
| 78 | if err != nil { |
| 79 | return nil, err |
| 80 | } |
| 81 | |
| 82 | if eth := getEthernetLayer(pkt); eth != nil { |
| 83 | ethernetLayer := &layers.Ethernet{ |
| 84 | SrcMAC: eth.SrcMAC, |
| 85 | DstMAC: eth.DstMAC, |
| 86 | EthernetType: layer.Type, |
| 87 | } |
| 88 | buffer := gopacket.NewSerializeBuffer() |
Shrey Baid | 688b424 | 2020-07-10 20:40:10 +0530 | [diff] [blame] | 89 | _ = gopacket.SerializeLayers(buffer, gopacket.SerializeOptions{}, |
Matteo Scandolo | 4b3fc7e | 2019-09-17 16:49:54 -0700 | [diff] [blame] | 90 | ethernetLayer, |
| 91 | gopacket.Payload(layer.Payload), |
| 92 | ) |
| 93 | retpkt := gopacket.NewPacket( |
| 94 | buffer.Bytes(), |
| 95 | layers.LayerTypeEthernet, |
| 96 | gopacket.Default, |
| 97 | ) |
| 98 | |
| 99 | return retpkt, nil |
| 100 | } |
| 101 | return nil, errors.New("no-ethernet-layer") |
| 102 | } |
| 103 | |
| 104 | func PopDoubleTag(pkt gopacket.Packet) (gopacket.Packet, error) { |
| 105 | packet, err := PopSingleTag(pkt) |
| 106 | if err != nil { |
| 107 | return nil, err |
| 108 | } |
| 109 | packet, err = PopSingleTag(packet) |
| 110 | if err != nil { |
| 111 | return nil, err |
| 112 | } |
| 113 | return packet, nil |
| 114 | } |
| 115 | |
| 116 | func getEthernetLayer(pkt gopacket.Packet) *layers.Ethernet { |
| 117 | eth := &layers.Ethernet{} |
| 118 | if ethLayer := pkt.Layer(layers.LayerTypeEthernet); ethLayer != nil { |
| 119 | eth, _ = ethLayer.(*layers.Ethernet) |
| 120 | } |
| 121 | return eth |
| 122 | } |
| 123 | |
| 124 | func getDot1QLayer(pkt gopacket.Packet) (*layers.Dot1Q, error) { |
Matteo Scandolo | 4b3fc7e | 2019-09-17 16:49:54 -0700 | [diff] [blame] | 125 | if dot1qLayer := pkt.Layer(layers.LayerTypeDot1Q); dot1qLayer != nil { |
Shrey Baid | 688b424 | 2020-07-10 20:40:10 +0530 | [diff] [blame] | 126 | dot1q := dot1qLayer.(*layers.Dot1Q) |
Matteo Scandolo | 4b3fc7e | 2019-09-17 16:49:54 -0700 | [diff] [blame] | 127 | return dot1q, nil |
| 128 | } |
| 129 | return nil, errors.New("no-dot1q-layer-in-packet") |
| 130 | } |
| 131 | |
Matteo Scandolo | f6f3a7f | 2019-10-11 11:19:29 -0700 | [diff] [blame] | 132 | func GetVlanTag(pkt gopacket.Packet) (uint16, error) { |
Matteo Scandolo | 4b3fc7e | 2019-09-17 16:49:54 -0700 | [diff] [blame] | 133 | dot1q, err := getDot1QLayer(pkt) |
| 134 | if err != nil { |
| 135 | return 0, err |
| 136 | } |
| 137 | return dot1q.VLANIdentifier, nil |
| 138 | } |
Matteo Scandolo | 8d28137 | 2020-09-03 16:23:37 -0700 | [diff] [blame] | 139 | |
| 140 | func GetPbit(pkt gopacket.Packet) (uint8, error) { |
| 141 | dot1q, err := getDot1QLayer(pkt) |
| 142 | if err != nil { |
| 143 | return 0, err |
| 144 | } |
| 145 | return dot1q.Priority, nil |
| 146 | } |
Matteo Scandolo | 90d08f6 | 2020-10-29 12:06:55 -0700 | [diff] [blame] | 147 | |
Elia Battiston | bed2d21 | 2022-02-02 16:23:31 +0100 | [diff] [blame] | 148 | // get inner and outer tag from a packet |
Matteo Scandolo | 90d08f6 | 2020-10-29 12:06:55 -0700 | [diff] [blame] | 149 | func GetTagsFromPacket(pkt gopacket.Packet) (uint16, uint16, error) { |
Elia Battiston | bed2d21 | 2022-02-02 16:23:31 +0100 | [diff] [blame] | 150 | oTag, err := GetVlanTag(pkt) |
Matteo Scandolo | 90d08f6 | 2020-10-29 12:06:55 -0700 | [diff] [blame] | 151 | if err != nil { |
| 152 | return 0, 0, err |
| 153 | } |
Elia Battiston | bed2d21 | 2022-02-02 16:23:31 +0100 | [diff] [blame] | 154 | |
| 155 | poppedTagPkt, err := PopSingleTag(pkt) |
Matteo Scandolo | 90d08f6 | 2020-10-29 12:06:55 -0700 | [diff] [blame] | 156 | if err != nil { |
| 157 | return 0, 0, err |
| 158 | } |
Elia Battiston | bed2d21 | 2022-02-02 16:23:31 +0100 | [diff] [blame] | 159 | |
| 160 | if dot1qLayer := poppedTagPkt.Layer(layers.LayerTypeDot1Q); dot1qLayer == nil { |
| 161 | //No other tag, the packet is single tagged |
| 162 | return oTag, 0, nil |
| 163 | } |
| 164 | |
| 165 | iTag, err := GetVlanTag(poppedTagPkt) |
Matteo Scandolo | 90d08f6 | 2020-10-29 12:06:55 -0700 | [diff] [blame] | 166 | if err != nil { |
| 167 | return 0, 0, err |
| 168 | } |
Elia Battiston | bed2d21 | 2022-02-02 16:23:31 +0100 | [diff] [blame] | 169 | return oTag, iTag, nil |
Matteo Scandolo | 90d08f6 | 2020-10-29 12:06:55 -0700 | [diff] [blame] | 170 | } |