1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
/*
* Copyright 2015 Open Networking Laboratory
*
* 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 org.onosproject.segmentrouting;
import org.onlab.packet.ARP;
import org.onlab.packet.Ethernet;
import org.onlab.packet.Ip4Address;
import org.onlab.packet.IpAddress;
import org.onlab.packet.MacAddress;
import org.onosproject.net.ConnectPoint;
import org.onosproject.net.DeviceId;
import org.onosproject.net.Host;
import org.onosproject.net.Port;
import org.onosproject.net.PortNumber;
import org.onosproject.net.flow.DefaultTrafficTreatment;
import org.onosproject.net.flow.TrafficTreatment;
import org.onosproject.net.packet.DefaultOutboundPacket;
import org.onosproject.net.packet.InboundPacket;
import org.onosproject.net.HostId;
import org.onosproject.net.packet.OutboundPacket;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.nio.ByteBuffer;
import java.util.List;
import static com.google.common.base.Preconditions.checkNotNull;
public class ArpHandler {
private static Logger log = LoggerFactory.getLogger(ArpHandler.class);
private SegmentRoutingManager srManager;
private DeviceConfiguration config;
/**
* Creates an ArpHandler object.
*
* @param srManager SegmentRoutingManager object
*/
public ArpHandler(SegmentRoutingManager srManager) {
this.srManager = srManager;
this.config = checkNotNull(srManager.deviceConfiguration);
}
/**
* Processes incoming ARP packets.
* If it is an ARP request to router itself or known hosts,
* then it sends ARP response.
* If it is an ARP request to unknown hosts in its own subnet,
* then it flood the ARP request to the ports.
* If it is an ARP response, then set a flow rule for the host
* and forward any IP packets to the host in the packet buffer to the host.
*
* @param pkt incoming packet
*/
public void processPacketIn(InboundPacket pkt) {
Ethernet ethernet = pkt.parsed();
ARP arp = (ARP) ethernet.getPayload();
ConnectPoint connectPoint = pkt.receivedFrom();
PortNumber inPort = connectPoint.port();
DeviceId deviceId = connectPoint.deviceId();
byte[] senderMacAddressByte = arp.getSenderHardwareAddress();
Ip4Address hostIpAddress = Ip4Address.valueOf(arp.getSenderProtocolAddress());
srManager.routingRulePopulator.populateIpRuleForHost(deviceId, hostIpAddress, MacAddress.
valueOf(senderMacAddressByte), inPort);
if (arp.getOpCode() == ARP.OP_REQUEST) {
handleArpRequest(deviceId, connectPoint, ethernet);
} else {
srManager.ipHandler.forwardPackets(deviceId, hostIpAddress);
}
}
private void handleArpRequest(DeviceId deviceId, ConnectPoint inPort, Ethernet payload) {
ARP arpRequest = (ARP) payload.getPayload();
HostId targetHostId = HostId.hostId(MacAddress.valueOf(
arpRequest.getTargetHardwareAddress()));
// ARP request for router
if (isArpReqForRouter(deviceId, arpRequest)) {
Ip4Address targetAddress = Ip4Address.valueOf(arpRequest.getTargetProtocolAddress());
sendArpResponse(arpRequest, config.getRouterMacForAGatewayIp(targetAddress));
} else {
Host targetHost = srManager.hostService.getHost(targetHostId);
// ARP request for known hosts
if (targetHost != null) {
sendArpResponse(arpRequest, targetHost.mac());
// ARP request for unknown host in the subnet
} else if (isArpReqForSubnet(deviceId, arpRequest)) {
flood(payload, inPort);
}
}
}
private boolean isArpReqForRouter(DeviceId deviceId, ARP arpRequest) {
List<Ip4Address> gatewayIpAddresses = config.getSubnetGatewayIps(deviceId);
if (gatewayIpAddresses != null) {
Ip4Address targetProtocolAddress = Ip4Address.valueOf(arpRequest
.getTargetProtocolAddress());
if (gatewayIpAddresses.contains(targetProtocolAddress)) {
return true;
}
}
return false;
}
private boolean isArpReqForSubnet(DeviceId deviceId, ARP arpRequest) {
return config.getSubnets(deviceId).stream()
.anyMatch((prefix)->
prefix.contains(Ip4Address.
valueOf(arpRequest.
getTargetProtocolAddress())));
}
/**
* Sends an APR request for the target IP address to all ports except in-port.
*
* @param deviceId Switch device ID
* @param targetAddress target IP address for ARP
* @param inPort in-port
*/
public void sendArpRequest(DeviceId deviceId, IpAddress targetAddress, ConnectPoint inPort) {
byte[] senderMacAddress = config.getDeviceMac(deviceId).toBytes();
byte[] senderIpAddress = config.getRouterIp(deviceId).toOctets();
ARP arpRequest = new ARP();
arpRequest.setHardwareType(ARP.HW_TYPE_ETHERNET)
.setProtocolType(ARP.PROTO_TYPE_IP)
.setHardwareAddressLength(
(byte) Ethernet.DATALAYER_ADDRESS_LENGTH)
.setProtocolAddressLength((byte) Ip4Address.BYTE_LENGTH)
.setOpCode(ARP.OP_REQUEST)
.setSenderHardwareAddress(senderMacAddress)
.setTargetHardwareAddress(MacAddress.ZERO.toBytes())
.setSenderProtocolAddress(senderIpAddress)
.setTargetProtocolAddress(targetAddress.toOctets());
Ethernet eth = new Ethernet();
eth.setDestinationMACAddress(MacAddress.BROADCAST.toBytes())
.setSourceMACAddress(senderMacAddress)
.setEtherType(Ethernet.TYPE_ARP).setPayload(arpRequest);
flood(eth, inPort);
}
private void sendArpResponse(ARP arpRequest, MacAddress targetMac) {
ARP arpReply = new ARP();
arpReply.setHardwareType(ARP.HW_TYPE_ETHERNET)
.setProtocolType(ARP.PROTO_TYPE_IP)
.setHardwareAddressLength(
(byte) Ethernet.DATALAYER_ADDRESS_LENGTH)
.setProtocolAddressLength((byte) Ip4Address.BYTE_LENGTH)
.setOpCode(ARP.OP_REPLY)
.setSenderHardwareAddress(targetMac.toBytes())
.setSenderProtocolAddress(arpRequest.getTargetProtocolAddress())
.setTargetHardwareAddress(arpRequest.getSenderHardwareAddress())
.setTargetProtocolAddress(arpRequest.getSenderProtocolAddress());
Ethernet eth = new Ethernet();
eth.setDestinationMACAddress(arpRequest.getSenderHardwareAddress())
.setSourceMACAddress(targetMac.toBytes())
.setEtherType(Ethernet.TYPE_ARP).setPayload(arpReply);
HostId dstId = HostId.hostId(MacAddress.valueOf(
arpReply.getTargetHardwareAddress()));
Host dst = srManager.hostService.getHost(dstId);
if (dst == null) {
log.warn("Cannot send ARP response to unknown device");
return;
}
TrafficTreatment treatment = DefaultTrafficTreatment.builder().
setOutput(dst.location().port()).build();
OutboundPacket packet = new DefaultOutboundPacket(dst.location().deviceId(),
treatment, ByteBuffer.wrap(eth.serialize()));
srManager.packetService.emit(packet);
}
private void flood(Ethernet request, ConnectPoint inPort) {
TrafficTreatment.Builder builder;
ByteBuffer buf = ByteBuffer.wrap(request.serialize());
for (Port port: srManager.deviceService.getPorts(inPort.deviceId())) {
if (!port.number().equals(inPort.port()) &&
port.number().toLong() > 0) {
builder = DefaultTrafficTreatment.builder();
builder.setOutput(port.number());
srManager.packetService.emit(new DefaultOutboundPacket(inPort.deviceId(),
builder.build(), buf));
}
}
}
}
|
