gomemif: introduce gomemif

golang native memif driver

Type: feature

Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>
Change-Id: I693156a44011c80025245d25134f5bf5db6eba82
Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>

1 files changed, 227 insertions, 0 deletions

diff --git a/extras/gomemif/examples/responder.go b/extras/gomemif/examples/responder.go
new file mode 100644
index 00000000000..8fda6435bc5
--- /dev/null
+++ b/extras/gomemif/examples/responder.go
@@ -0,0 +1,227 @@
+/*
+ *------------------------------------------------------------------
+ * 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)
+}