summaryrefslogtreecommitdiffstats
path: root/extras/gomemif/examples/responder.go
blob: 8fda6435bc52623c39ed9e94ebb659fb2cb02fe3 (plain)
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
218
219
220
221
222
223
224
225
226
227
/*
 *------------------------------------------------------------------
 * Copyright (c) 2020 Cisco and/or its affiliates.
 * 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 main

import (
	"bufio"
	"flag"
	"fmt"
	"os"
	"strings"
	"sync"

	"github.com/pkg/profile"
	"memif"
)

func Disconnected(i *memif.Interface) error {
	fmt.Println("Disconnected: ", i.GetName())

	data, ok := i.GetPrivateData().(*interfaceData)
	if !ok {
		return fmt.Errorf("Invalid private data")
	}
	close(data.quitChan) // stop polling
	close(data.errChan)
	data.wg.Wait() // wait until polling stops, then continue disconnect

	return nil
}

func Connected(i *memif.Interface) error {
	fmt.Println("Connected: ", i.GetName())

	data, ok := i.GetPrivateData().(*interfaceData)
	if !ok {
		return fmt.Errorf("Invalid private data")
	}
	data.errChan = make(chan error, 1)
	data.quitChan = make(chan struct{}, 1)
	data.wg.Add(1)

	go func(errChan chan<- error, quitChan <-chan struct{}, wg *sync.WaitGroup) {
		defer wg.Done()
		// allocate packet buffer
		pkt := make([]byte, 2048)
		// get rx queue
		rxq0, err := i.GetRxQueue(0)
		if err != nil {
			errChan <- err
			return
		}
		// get tx queue
		txq0, err := i.GetTxQueue(0)
		if err != nil {
			errChan <- err
			return
		}
		for {
			select {
			case <-quitChan: // channel closed
				return
			default:
				// read packet from shared memory
				pktLen, err := rxq0.ReadPacket(pkt)
				if pktLen > 0 {
					// write packet to shared memory
					txq0.WritePacket(pkt[:pktLen])
				} else if err != nil {
					errChan <- err
					return
				}
			}
		}
	}(data.errChan, data.quitChan, &data.wg)

	return nil
}

type interfaceData struct {
	errChan  chan error
	quitChan chan struct{}
	wg       sync.WaitGroup
}

func interractiveHelp() {
	fmt.Println("help - print this help")
	fmt.Println("start - start connecting loop")
	fmt.Println("show - print interface details")
	fmt.Println("exit - exit the application")
}

func main() {
	cpuprof := flag.String("cpuprof", "", "cpu profiling output file")
	memprof := flag.String("memprof", "", "mem profiling output file")
	role := flag.String("role", "slave", "interface role")
	name := flag.String("name", "gomemif", "interface name")
	socketName := flag.String("socket", "", "control socket filename")

	flag.Parse()

	if *cpuprof != "" {
		defer profile.Start(profile.CPUProfile, profile.ProfilePath(*cpuprof)).Stop()
	}
	if *memprof != "" {
		defer profile.Start(profile.MemProfile, profile.ProfilePath(*memprof)).Stop()
	}

	memifErrChan := make(chan error)
	exitChan := make(chan struct{})

	var isMaster bool
	switch *role {
	case "slave":
		isMaster = false
	case "master":
		isMaster = true
	default:
		fmt.Println("Invalid role")
		return
	}

	fmt.Println("GoMemif: Responder")
	fmt.Println("-----------------------")

	socket, err := memif.NewSocket("gomemif_example", *socketName)
	if err != nil {
		fmt.Println("Failed to create socket: ", err)
		return
	}

	data := interfaceData{}
	args := &memif.Arguments{
		IsMaster:         isMaster,
		ConnectedFunc:    Connected,
		DisconnectedFunc: Disconnected,
		PrivateData:      &data,
		Name:             *name,
	}

	i, err := socket.NewInterface(args)
	if err != nil {
		fmt.Println("Failed to create interface on socket %s: %s", socket.GetFilename(), err)
		goto exit
	}

	// slave attempts to connect to control socket
	// to handle control communication call socket.StartPolling()
	if !i.IsMaster() {
		fmt.Println(args.Name, ": Connecting to control socket...")
		for !i.IsConnecting() {
			err = i.RequestConnection()
			if err != nil {
				/* TODO: check for ECONNREFUSED errno
				 * if error is ECONNREFUSED it may simply mean that master
				 * interface is not up yet, use i.RequestConnection()
				 */
				fmt.Println("Faild to connect: ", err)
				goto exit
			}
		}
	}

	go func(exitChan chan<- struct{}) {
		reader := bufio.NewReader(os.Stdin)
		for {
			fmt.Print("gomemif# ")
			text, _ := reader.ReadString('\n')
			// convert CRLF to LF
			text = strings.Replace(text, "\n", "", -1)
			switch text {
			case "help":
				interractiveHelp()
			case "start":
				// start polling for events on this socket
				socket.StartPolling(memifErrChan)
			case "show":
				fmt.Println("remote: ", i.GetRemoteName())
				fmt.Println("peer: ", i.GetPeerName())
			case "exit":
				err = socket.StopPolling()
				if err != nil {
					fmt.Println("Failed to stop polling: ", err)
				}
				close(exitChan)
				return
			default:
				fmt.Println("Unknown input")
			}
		}
	}(exitChan)

	for {
		select {
		case <-exitChan:
			goto exit
		case err, ok := <-memifErrChan:
			if ok {
				fmt.Println(err)
			}
		case err, ok := <-data.errChan:
			if ok {
				fmt.Println(err)
			}
		default:
			continue
		}
	}

exit:
	socket.Delete()
	close(memifErrChan)
}