blob: 9ada88c6cb79b3cf782cdb4e9c935267179325c2 [file] [log] [blame]
Matteo Scandolo4b3fc7e2019-09-17 16:49:54 -07001/*
2 * Copyright 2018-present Open Networking Foundation
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
17package packetHandlers
18
19import (
Matteo Scandolof6f3a7f2019-10-11 11:19:29 -070020 "errors"
Matteo Scandolo4b3fc7e2019-09-17 16:49:54 -070021 "github.com/google/gopacket"
22 "github.com/google/gopacket/layers"
23 "net"
24)
25
26func IsDhcpPacket(pkt gopacket.Packet) bool {
27 if layerDHCP := pkt.Layer(layers.LayerTypeDHCPv4); layerDHCP != nil {
28 return true
29 }
30 return false
31}
32
Matteo Scandolo73c488d2019-11-01 14:44:22 -070033func IsLldpPacket(pkt gopacket.Packet) bool {
34 if layer := pkt.Layer(layers.LayerTypeLinkLayerDiscovery); layer != nil {
35 return true
36 }
37 return false
38}
39
Matteo Scandolof6f3a7f2019-10-11 11:19:29 -070040// return true if the packet is coming in the OLT from the NNI port
41// it uses the ack to check if the source is the one we assigned to the
42// dhcp server
Matteo Scandolo4b3fc7e2019-09-17 16:49:54 -070043func IsIncomingPacket(packet gopacket.Packet) bool {
44 if ipLayer := packet.Layer(layers.LayerTypeIPv4); ipLayer != nil {
45
46 ip, _ := ipLayer.(*layers.IPv4)
47
48 // FIXME find a better way to filter outgoing packets
Matteo Scandolo40e067f2019-10-16 16:59:41 -070049 if ip.SrcIP.Equal(net.ParseIP("192.168.254.1")) {
Matteo Scandolo4b3fc7e2019-09-17 16:49:54 -070050 return true
51 }
52 }
53 return false
54}
Matteo Scandolof6f3a7f2019-10-11 11:19:29 -070055
Matteo Scandolo40e067f2019-10-16 16:59:41 -070056// returns the Destination Mac Address contained in the packet
Matteo Scandolof6f3a7f2019-10-11 11:19:29 -070057func GetDstMacAddressFromPacket(packet gopacket.Packet) (net.HardwareAddr, error) {
58 if ethLayer := packet.Layer(layers.LayerTypeEthernet); ethLayer != nil {
59 eth, _ := ethLayer.(*layers.Ethernet)
60
61 if eth.DstMAC != nil {
62 return eth.DstMAC, nil
63 }
64 }
65 return nil, errors.New("cant-find-mac-address")
66}
Matteo Scandolo40e067f2019-10-16 16:59:41 -070067
68// returns the Source Mac Address contained in the packet
69func GetSrcMacAddressFromPacket(packet gopacket.Packet) (net.HardwareAddr, error) {
70 if ethLayer := packet.Layer(layers.LayerTypeEthernet); ethLayer != nil {
71 eth, _ := ethLayer.(*layers.Ethernet)
72
73 if eth.DstMAC != nil {
74 return eth.SrcMAC, nil
75 }
76 }
77 return nil, errors.New("cant-find-mac-address")
78}
79
80// returns wether it's an EAPOL or DHCP packet, error if it's none
81func IsEapolOrDhcp(pkt gopacket.Packet) (PacketType, error) {
82 if pkt.Layer(layers.LayerTypeEAP) != nil || pkt.Layer(layers.LayerTypeEAPOL) != nil {
83 return EAPOL, nil
84 } else if IsDhcpPacket(pkt) {
85 return DHCP, nil
86 }
87 return UNKNOWN, errors.New("packet-is-neither-eapol-or-dhcp")
88}