1 files changed, 269 insertions, 0 deletions
diff --git a/examples/example_client.go b/examples/example_client.go
new file mode 100644
index 0000000..fd858ee
--- /dev/null
+++ b/examples/example_client.go
@@ -0,0 +1,269 @@
+// Copyright (c) 2017 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.
+
+// Example VPP management application that exercises the govpp API on real-world use-cases.
+package main
+
+// Generates Go bindings for all VPP APIs located in the json directory.
+//go:generate binapi_generator --input-dir=bin_api --output-dir=bin_api
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"os/signal"
+
+	"gerrit.fd.io/r/govpp"
+	"gerrit.fd.io/r/govpp/api"
+	"gerrit.fd.io/r/govpp/api/ifcounters"
+	"gerrit.fd.io/r/govpp/core/bin_api/vpe"
+	"gerrit.fd.io/r/govpp/examples/bin_api/acl"
+	"gerrit.fd.io/r/govpp/examples/bin_api/interfaces"
+	"gerrit.fd.io/r/govpp/examples/bin_api/tap"
+)
+
+func main() {
+	fmt.Println("Starting example VPP client...")
+
+	// connect to VPP and create an API channel that will be used in the examples
+	conn, _ := govpp.Connect()
+	defer conn.Disconnect()
+
+	ch, _ := conn.NewAPIChannel()
+	defer ch.Close()
+
+	// check whether the VPP supports our version of some messages
+	compatibilityCheck(ch)
+
+	// individual examples
+	aclVersion(ch)
+	aclConfig(ch)
+	aclDump(ch)
+
+	tapConnect(ch)
+
+	interfaceDump(ch)
+	interfaceNotifications(ch)
+
+	//interfaceCounters(ch)
+}
+
+// compatibilityCheck shows how an management application can check whether generated API messages are
+// compatible with the version of VPP which the library is connected to.
+func compatibilityCheck(ch *api.Channel) {
+	err := ch.CheckMessageCompatibility(
+		&interfaces.SwInterfaceDump{},
+		&interfaces.SwInterfaceDetails{},
+	)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
+
+// aclVersion is the simplest API example - one empty request message and one reply message.
+func aclVersion(ch *api.Channel) {
+	req := &acl.ACLPluginGetVersion{}
+	reply := &acl.ACLPluginGetVersionReply{}
+
+	err := ch.SendRequest(req).ReceiveReply(reply)
+
+	if err != nil {
+		fmt.Println("Error:", err)
+	} else {
+		fmt.Printf("%+v\n", reply)
+	}
+}
+
+// aclConfig is another simple API example - in this case, the request contains structured data.
+func aclConfig(ch *api.Channel) {
+	req := &acl.ACLAddReplace{
+		ACLIndex: ^uint32(0),
+		Tag:      []byte("access list 1"),
+		R: []acl.ACLRule{
+			{
+				IsPermit:       1,
+				SrcIPAddr:      net.ParseIP("10.0.0.0").To4(),
+				SrcIPPrefixLen: 8,
+				DstIPAddr:      net.ParseIP("192.168.1.0").To4(),
+				DstIPPrefixLen: 24,
+				Proto:          6,
+			},
+			{
+				IsPermit:       1,
+				SrcIPAddr:      net.ParseIP("8.8.8.8").To4(),
+				SrcIPPrefixLen: 32,
+				DstIPAddr:      net.ParseIP("172.16.0.0").To4(),
+				DstIPPrefixLen: 16,
+				Proto:          6,
+			},
+		},
+	}
+	reply := &acl.ACLAddReplaceReply{}
+
+	err := ch.SendRequest(req).ReceiveReply(reply)
+
+	if err != nil {
+		fmt.Println("Error:", err)
+	} else {
+		fmt.Printf("%+v\n", reply)
+	}
+}
+
+// aclDump shows an example where SendRequest and ReceiveReply are not chained together.
+func aclDump(ch *api.Channel) {
+	req := &acl.ACLDump{}
+	reply := &acl.ACLDetails{}
+
+	reqCtx := ch.SendRequest(req)
+	err := reqCtx.ReceiveReply(reply)
+
+	if err != nil {
+		fmt.Println("Error:", err)
+	} else {
+		fmt.Printf("%+v\n", reply)
+	}
+}
+
+// tapConnect example shows how the Go channels in the API channel can be accessed directly instead
+// of using SendRequest and ReceiveReply wrappers.
+func tapConnect(ch *api.Channel) {
+	req := &tap.TapConnect{
+		TapName:      []byte("testtap"),
+		UseRandomMac: 1,
+	}
+
+	// send the request to the request go channel
+	ch.ReqChan <- &api.VppRequest{Message: req}
+
+	// receive a reply from the reply go channel
+	vppReply := <-ch.ReplyChan
+	if vppReply.Error != nil {
+		fmt.Println("Error:", vppReply.Error)
+		return
+	}
+
+	// decode the message
+	reply := &tap.TapConnectReply{}
+	err := ch.MsgDecoder.DecodeMsg(vppReply.Data, reply)
+
+	if err != nil {
+		fmt.Println("Error:", err)
+	} else {
+		fmt.Printf("%+v\n", reply)
+	}
+}
+
+// interfaceDump shows an example of multipart request (multiple replies are expected).
+func interfaceDump(ch *api.Channel) {
+	req := &interfaces.SwInterfaceDump{}
+	reqCtx := ch.SendMultiRequest(req)
+
+	for {
+		msg := &interfaces.SwInterfaceDetails{}
+		stop, err := reqCtx.ReceiveReply(msg)
+		if stop {
+			break // break out of the loop
+		}
+		if err != nil {
+			fmt.Println("Error:", err)
+		}
+		fmt.Printf("%+v\n", msg)
+	}
+}
+
+// interfaceNotifications shows the usage of notification API. Note that for notifications,
+// you are supposed to create your own Go channel with your preferred buffer size. If the channel's
+// buffer is full, the notifications will not be delivered into it.
+func interfaceNotifications(ch *api.Channel) {
+	// subscribe for specific notification message
+	notifChan := make(chan api.Message, 100)
+	subs, _ := ch.SubscribeNotification(notifChan, interfaces.NewSwInterfaceSetFlags)
+
+	// enable interface events in VPP
+	ch.SendRequest(&interfaces.WantInterfaceEvents{
+		Pid:           uint32(os.Getpid()),
+		EnableDisable: 1,
+	}).ReceiveReply(&interfaces.WantInterfaceEventsReply{})
+
+	// generate some events in VPP
+	ch.SendRequest(&interfaces.SwInterfaceSetFlags{
+		SwIfIndex:   0,
+		AdminUpDown: 0,
+	}).ReceiveReply(&interfaces.SwInterfaceSetFlagsReply{})
+	ch.SendRequest(&interfaces.SwInterfaceSetFlags{
+		SwIfIndex:   0,
+		AdminUpDown: 1,
+	}).ReceiveReply(&interfaces.SwInterfaceSetFlagsReply{})
+
+	// receive one notification
+	notif := (<-notifChan).(*interfaces.SwInterfaceSetFlags)
+	fmt.Printf("%+v\n", notif)
+
+	// unsubscribe from delivery of the notifications
+	ch.UnsubscribeNotification(subs)
+}
+
+// interfaceCounters is an example of using notification API to periodically retrieve interface statistics.
+// The ifcounters package contains the API that can be used to decode the strange VnetInterfaceCounters message.
+func interfaceCounters(ch *api.Channel) {
+	// subscribe for interface counters notifications
+	notifChan := make(chan api.Message, 100)
+	subs, _ := ch.SubscribeNotification(notifChan, interfaces.NewVnetInterfaceCounters)
+
+	// enable interface counters notifications from VPP
+	ch.SendRequest(&vpe.WantStats{
+		Pid:           uint32(os.Getpid()),
+		EnableDisable: 1,
+	}).ReceiveReply(&vpe.WantStatsReply{})
+
+	// create channel for Interrupt signal
+	sigChan := make(chan os.Signal, 1)
+	signal.Notify(sigChan, os.Interrupt)
+
+	// loop until Interrupt signal is received
+loop:
+	for {
+		select {
+		case <-sigChan:
+			// interrupt received
+			break loop
+		case notifMsg := <-notifChan:
+			notif := notifMsg.(*interfaces.VnetInterfaceCounters)
+			// notification received
+			fmt.Printf("%+v\n", notif)
+
+			if notif.IsCombined == 0 {
+				// simple counter
+				counters, err := ifcounters.DecodeCounters(ifcounters.VnetInterfaceCounters(*notif))
+				if err != nil {
+					fmt.Println("Error:", err)
+				} else {
+					fmt.Printf("%+v\n", counters)
+				}
+			} else {
+				// combined counter
+				counters, err := ifcounters.DecodeCombinedCounters(ifcounters.VnetInterfaceCounters(*notif))
+				if err != nil {
+					fmt.Println("Error:", err)
+				} else {
+					fmt.Printf("%+v\n", counters)
+				}
+			}
+		}
+	}
+
+	// unsubscribe from delivery of the notifications
+	ch.UnsubscribeNotification(subs)
+}