examples/simple-client/simple_client.go

   1 // Copyright (c) 2017 Cisco and/or its affiliates.
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at:
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 // simple-client is an example VPP management application that exercises the
  16 // govpp API on real-world use-cases.
  17 package main
  18
  19 import (
  20         "encoding/json"
  21         "flag"
  22         "fmt"
  23         "log"
  24         "os"
  25
  26         "git.fd.io/govpp.git"
  27         "git.fd.io/govpp.git/adapter/socketclient"
  28         "git.fd.io/govpp.git/api"
  29         interfaces "git.fd.io/govpp.git/binapi/interface"
  30         "git.fd.io/govpp.git/binapi/interface_types"
  31         "git.fd.io/govpp.git/binapi/ip"
  32         "git.fd.io/govpp.git/binapi/ip_types"
  33         "git.fd.io/govpp.git/binapi/vpe"
  34         "git.fd.io/govpp.git/core"
  35 )
  36
  37 var (
  38         sockAddr = flag.String("sock", socketclient.DefaultSocketName, "Path to VPP binary API socket file")
  39 )
  40
  41 func main() {
  42         flag.Parse()
  43
  44         fmt.Println("Starting simple client example")
  45         fmt.Println()
  46
  47         // connect to VPP asynchronously
  48         conn, connEv, err := govpp.AsyncConnect(*sockAddr, core.DefaultMaxReconnectAttempts, core.DefaultReconnectInterval)
  49         if err != nil {
  50                 log.Fatalln("ERROR:", err)
  51         }
  52         defer conn.Disconnect()
  53
  54         // wait for Connected event
  55         select {
  56         case e := <-connEv:
  57                 if e.State != core.Connected {
  58                         log.Fatalln("ERROR: connecting to VPP failed:", e.Error)
  59                 }
  60         }
  61
  62         // check compatibility of used messages
  63         ch, err := conn.NewAPIChannel()
  64         if err != nil {
  65                 log.Fatalln("ERROR: creating channel failed:", err)
  66         }
  67         defer ch.Close()
  68         if err := ch.CheckCompatiblity(vpe.AllMessages()...); err != nil {
  69                 log.Fatal(err)
  70         }
  71         if err := ch.CheckCompatiblity(interfaces.AllMessages()...); err != nil {
  72                 log.Fatal(err)
  73         }
  74
  75         // process errors encountered during the example
  76         defer func() {
  77                 if len(Errors) > 0 {
  78                         fmt.Printf("finished with %d errors\n", len(Errors))
  79                         os.Exit(1)
  80                 } else {
  81                         fmt.Println("finished successfully")
  82                 }
  83         }()
  84
  85         // use request/reply (channel API)
  86         getVppVersion(ch)
  87         idx := createLoopback(ch)
  88         interfaceDump(ch)
  89         addIPAddress(ch, idx)
  90         ipAddressDump(ch, idx)
  91         interfaceNotifications(ch, idx)
  92 }
  93
  94 func getVppVersion(ch api.Channel) {
  95         fmt.Println("Retrieving version..")
  96
  97         req := &vpe.ShowVersion{}
  98         reply := &vpe.ShowVersionReply{}
  99
 100         if err := ch.SendRequest(req).ReceiveReply(reply); err != nil {
 101                 logError(err, "retrieving version")
 102                 return
 103         }
 104
 105         fmt.Printf("VPP version: %q\n", reply.Version)
 106         fmt.Println("OK")
 107         fmt.Println()
 108 }
 109
 110 func createLoopback(ch api.Channel) interface_types.InterfaceIndex {
 111         fmt.Println("Creating loopback interface..")
 112
 113         req := &interfaces.CreateLoopback{}
 114         reply := &interfaces.CreateLoopbackReply{}
 115
 116         if err := ch.SendRequest(req).ReceiveReply(reply); err != nil {
 117                 logError(err, "creating loopback interface")
 118                 return 0
 119         }
 120
 121         fmt.Printf("interface index: %v\n", reply.SwIfIndex)
 122         fmt.Println("OK")
 123         fmt.Println()
 124
 125         return reply.SwIfIndex
 126 }
 127
 128 func interfaceDump(ch api.Channel) {
 129         fmt.Println("Dumping interfaces..")
 130
 131         n := 0
 132         reqCtx := ch.SendMultiRequest(&interfaces.SwInterfaceDump{
 133                 SwIfIndex: ^interface_types.InterfaceIndex(0),
 134         })
 135         for {
 136                 msg := &interfaces.SwInterfaceDetails{}
 137                 stop, err := reqCtx.ReceiveReply(msg)
 138                 if stop {
 139                         break
 140                 }
 141                 if err != nil {
 142                         logError(err, "dumping interfaces")
 143                         return
 144                 }
 145                 n++
 146                 fmt.Printf(" - interface #%d: %+v\n", n, msg)
 147                 marshal(msg)
 148         }
 149
 150         fmt.Println("OK")
 151         fmt.Println()
 152 }
 153
 154 func addIPAddress(ch api.Channel, index interface_types.InterfaceIndex) {
 155         fmt.Printf("Adding IP address to interface index %d\n", index)
 156
 157         req := &interfaces.SwInterfaceAddDelAddress{
 158                 SwIfIndex: index,
 159                 IsAdd:     true,
 160                 Prefix: ip_types.AddressWithPrefix{
 161                         Address: ip_types.Address{
 162                                 Af: ip_types.ADDRESS_IP4,
 163                                 Un: ip_types.AddressUnionIP4(ip_types.IP4Address{10, 10, 0, uint8(index)}),
 164                         },
 165                         Len: 32,
 166                 },
 167         }
 168         marshal(req)
 169         reply := &interfaces.SwInterfaceAddDelAddressReply{}
 170
 171         if err := ch.SendRequest(req).ReceiveReply(reply); err != nil {
 172                 logError(err, "adding IP address to interface")
 173                 return
 174         }
 175
 176         fmt.Println("OK")
 177         fmt.Println()
 178 }
 179
 180 func ipAddressDump(ch api.Channel, index interface_types.InterfaceIndex) {
 181         fmt.Printf("Dumping IP addresses for interface index %d..\n", index)
 182
 183         req := &ip.IPAddressDump{
 184                 SwIfIndex: index,
 185         }
 186         reqCtx := ch.SendMultiRequest(req)
 187
 188         for {
 189                 msg := &ip.IPAddressDetails{}
 190                 stop, err := reqCtx.ReceiveReply(msg)
 191                 if err != nil {
 192                         logError(err, "dumping IP addresses")
 193                         return
 194                 }
 195                 if stop {
 196                         break
 197                 }
 198                 fmt.Printf(" - ip address: %+v\n", msg)
 199                 marshal(msg)
 200         }
 201
 202         fmt.Println("OK")
 203         fmt.Println()
 204 }
 205
 206 // interfaceNotifications shows the usage of notification API. Note that for notifications,
 207 // you are supposed to create your own Go channel with your preferred buffer size. If the channel's
 208 // buffer is full, the notifications will not be delivered into it.
 209 func interfaceNotifications(ch api.Channel, index interface_types.InterfaceIndex) {
 210         fmt.Printf("Subscribing to notificaiton events for interface index %d\n", index)
 211
 212         notifChan := make(chan api.Message, 100)
 213
 214         // subscribe for specific notification message
 215         sub, err := ch.SubscribeNotification(notifChan, &interfaces.SwInterfaceEvent{})
 216         if err != nil {
 217                 logError(err, "subscribing to interface events")
 218                 return
 219         }
 220
 221         // enable interface events in VPP
 222         err = ch.SendRequest(&interfaces.WantInterfaceEvents{
 223                 PID:           uint32(os.Getpid()),
 224                 EnableDisable: 1,
 225         }).ReceiveReply(&interfaces.WantInterfaceEventsReply{})
 226         if err != nil {
 227                 logError(err, "enabling interface events")
 228                 return
 229         }
 230
 231         // receive notifications
 232         go func() {
 233                 for notif := range notifChan {
 234                         e := notif.(*interfaces.SwInterfaceEvent)
 235                         fmt.Printf("incoming event: %+v\n", e)
 236                         marshal(e)
 237                 }
 238         }()
 239
 240         // generate some events in VPP
 241         err = ch.SendRequest(&interfaces.SwInterfaceSetFlags{
 242                 SwIfIndex: index,
 243                 Flags:     interface_types.IF_STATUS_API_FLAG_ADMIN_UP,
 244         }).ReceiveReply(&interfaces.SwInterfaceSetFlagsReply{})
 245         if err != nil {
 246                 logError(err, "setting interface flags")
 247                 return
 248         }
 249         err = ch.SendRequest(&interfaces.SwInterfaceSetFlags{
 250                 SwIfIndex: index,
 251                 Flags:     0,
 252         }).ReceiveReply(&interfaces.SwInterfaceSetFlagsReply{})
 253         if err != nil {
 254                 logError(err, "setting interface flags")
 255                 return
 256         }
 257
 258         // disable interface events in VPP
 259         err = ch.SendRequest(&interfaces.WantInterfaceEvents{
 260                 PID:           uint32(os.Getpid()),
 261                 EnableDisable: 0,
 262         }).ReceiveReply(&interfaces.WantInterfaceEventsReply{})
 263         if err != nil {
 264                 logError(err, "setting interface flags")
 265                 return
 266         }
 267
 268         // unsubscribe from delivery of the notifications
 269         err = sub.Unsubscribe()
 270         if err != nil {
 271                 logError(err, "unsubscribing from interface events")
 272                 return
 273         }
 274
 275         fmt.Println("OK")
 276         fmt.Println()
 277 }
 278
 279 func marshal(v interface{}) {
 280         fmt.Printf("GO: %#v\n", v)
 281         b, err := json.MarshalIndent(v, "", "  ")
 282         if err != nil {
 283                 panic(err)
 284         }
 285         fmt.Printf("JSON: %s\n", b)
 286 }
 287
 288 var Errors []error
 289
 290 func logError(err error, msg string) {
 291         fmt.Printf("ERROR: %s: %v\n", msg, err)
 292         Errors = append(Errors, err)
 293 }