1 // Copyright (c) 2017 Cisco and/or its affiliates.
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:
7 // http://www.apache.org/licenses/LICENSE-2.0
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.
25 logger "github.com/sirupsen/logrus"
27 "git.fd.io/govpp.git/adapter"
28 "git.fd.io/govpp.git/api"
29 "git.fd.io/govpp.git/codec"
33 DefaultReconnectInterval = time.Second // default interval between reconnect attempts
34 DefaultMaxReconnectAttempts = 3 // default maximum number of reconnect attempts
38 RequestChanBufSize = 100 // default size of the request channel buffer
39 ReplyChanBufSize = 100 // default size of the reply channel buffer
40 NotificationChanBufSize = 100 // default size of the notification channel buffer
44 HealthCheckProbeInterval = time.Second // default health check probe interval
45 HealthCheckReplyTimeout = time.Millisecond * 100 // timeout for reply to a health check probe
46 HealthCheckThreshold = 1 // number of failed health checks until the error is reported
47 DefaultReplyTimeout = time.Second // default timeout for replies from VPP
50 // ConnectionState represents the current state of the connection to VPP.
51 type ConnectionState int
54 // Connected represents state in which the connection has been successfully established.
55 Connected ConnectionState = iota
57 // Disconnected represents state in which the connection has been dropped.
60 // Failed represents state in which the reconnecting failed after exceeding maximum number of attempts.
64 func (s ConnectionState) String() string {
73 return fmt.Sprintf("UnknownState(%d)", s)
77 // ConnectionEvent is a notification about change in the VPP connection state.
78 type ConnectionEvent struct {
79 // Timestamp holds the time when the event has been created.
82 // State holds the new state of the connection at the time when the event has been created.
85 // Error holds error if any encountered.
89 // Connection represents a shared memory connection to VPP via vppAdapter.
90 type Connection struct {
91 vppClient adapter.VppAPI // VPP binary API client
92 //statsClient adapter.StatsAPI // VPP stats API client
94 maxAttempts int // interval for reconnect attempts
95 recInterval time.Duration // maximum number of reconnect attempts
97 vppConnected uint32 // non-zero if the adapter is connected to VPP
99 codec *codec.MsgCodec // message codec
100 msgIDs map[string]uint16 // map of message IDs indexed by message name + CRC
101 msgMap map[uint16]api.Message // map of messages indexed by message ID
103 maxChannelID uint32 // maximum used channel ID (the real limit is 2^15, 32-bit is used for atomic operations)
104 channelsLock sync.RWMutex // lock for the channels map
105 channels map[uint16]*Channel // map of all API channels indexed by the channel ID
107 subscriptionsLock sync.RWMutex // lock for the subscriptions map
108 subscriptions map[uint16][]*subscriptionCtx // map od all notification subscriptions indexed by message ID
110 pingReqID uint16 // ID if the ControlPing message
111 pingReplyID uint16 // ID of the ControlPingReply message
113 lastReplyLock sync.Mutex // lock for the last reply
114 lastReply time.Time // time of the last received reply from VPP
117 func newConnection(binapi adapter.VppAPI, attempts int, interval time.Duration) *Connection {
119 attempts = DefaultMaxReconnectAttempts
122 interval = DefaultReconnectInterval
127 maxAttempts: attempts,
128 recInterval: interval,
129 codec: &codec.MsgCodec{},
130 msgIDs: make(map[string]uint16),
131 msgMap: make(map[uint16]api.Message),
132 channels: make(map[uint16]*Channel),
133 subscriptions: make(map[uint16][]*subscriptionCtx),
135 binapi.SetMsgCallback(c.msgCallback)
139 // Connect connects to VPP API using specified adapter and returns a connection handle.
140 // This call blocks until it is either connected, or an error occurs.
141 // Only one connection attempt will be performed.
142 func Connect(binapi adapter.VppAPI) (*Connection, error) {
143 // create new connection handle
144 c := newConnection(binapi, DefaultMaxReconnectAttempts, DefaultReconnectInterval)
146 // blocking attempt to connect to VPP
147 if err := c.connectVPP(); err != nil {
154 // AsyncConnect asynchronously connects to VPP using specified VPP adapter and returns the connection handle
155 // and ConnectionState channel. This call does not block until connection is established, it
156 // returns immediately. The caller is supposed to watch the returned ConnectionState channel for
157 // Connected/Disconnected events. In case of disconnect, the library will asynchronously try to reconnect.
158 func AsyncConnect(binapi adapter.VppAPI, attempts int, interval time.Duration) (*Connection, chan ConnectionEvent, error) {
159 // create new connection handle
160 c := newConnection(binapi, attempts, interval)
162 // asynchronously attempt to connect to VPP
163 connChan := make(chan ConnectionEvent, NotificationChanBufSize)
164 go c.connectLoop(connChan)
166 return c, connChan, nil
169 // connectVPP performs blocking attempt to connect to VPP.
170 func (c *Connection) connectVPP() error {
171 log.Debug("Connecting to VPP..")
174 if err := c.vppClient.Connect(); err != nil {
178 log.Debugf("Connected to VPP.")
180 if err := c.retrieveMessageIDs(); err != nil {
181 c.vppClient.Disconnect()
182 return fmt.Errorf("VPP is incompatible: %v", err)
185 // store connected state
186 atomic.StoreUint32(&c.vppConnected, 1)
191 // Disconnect disconnects from VPP API and releases all connection-related resources.
192 func (c *Connection) Disconnect() {
197 if c.vppClient != nil {
202 // disconnectVPP disconnects from VPP in case it is connected.
203 func (c *Connection) disconnectVPP() {
204 if atomic.CompareAndSwapUint32(&c.vppConnected, 1, 0) {
205 c.vppClient.Disconnect()
209 func (c *Connection) NewAPIChannel() (api.Channel, error) {
210 return c.newAPIChannel(RequestChanBufSize, ReplyChanBufSize)
213 func (c *Connection) NewAPIChannelBuffered(reqChanBufSize, replyChanBufSize int) (api.Channel, error) {
214 return c.newAPIChannel(reqChanBufSize, replyChanBufSize)
217 // NewAPIChannelBuffered returns a new API channel for communication with VPP via govpp core.
218 // It allows to specify custom buffer sizes for the request and reply Go channels.
219 func (c *Connection) newAPIChannel(reqChanBufSize, replyChanBufSize int) (*Channel, error) {
221 return nil, errors.New("nil connection passed in")
224 // create new channel
225 chID := uint16(atomic.AddUint32(&c.maxChannelID, 1) & 0x7fff)
226 channel := newChannel(chID, c, c.codec, c, reqChanBufSize, replyChanBufSize)
228 // store API channel within the client
229 c.channelsLock.Lock()
230 c.channels[chID] = channel
231 c.channelsLock.Unlock()
233 // start watching on the request channel
234 go c.watchRequests(channel)
239 // releaseAPIChannel releases API channel that needs to be closed.
240 func (c *Connection) releaseAPIChannel(ch *Channel) {
241 log.WithFields(logger.Fields{
243 }).Debug("API channel released")
245 // delete the channel from channels map
246 c.channelsLock.Lock()
247 delete(c.channels, ch.id)
248 c.channelsLock.Unlock()
251 // connectLoop attempts to connect to VPP until it succeeds.
252 // Then it continues with healthCheckLoop.
253 func (c *Connection) connectLoop(connChan chan ConnectionEvent) {
254 reconnectAttempts := 0
256 // loop until connected
258 if err := c.vppClient.WaitReady(); err != nil {
259 log.Warnf("wait ready failed: %v", err)
261 if err := c.connectVPP(); err == nil {
262 // signal connected event
263 connChan <- ConnectionEvent{Timestamp: time.Now(), State: Connected}
265 } else if reconnectAttempts < c.maxAttempts {
267 log.Errorf("connecting failed (attempt %d/%d): %v", reconnectAttempts, c.maxAttempts, err)
268 time.Sleep(c.recInterval)
270 connChan <- ConnectionEvent{Timestamp: time.Now(), State: Failed, Error: err}
275 // we are now connected, continue with health check loop
276 c.healthCheckLoop(connChan)
279 // healthCheckLoop checks whether connection to VPP is alive. In case of disconnect,
280 // it continues with connectLoop and tries to reconnect.
281 func (c *Connection) healthCheckLoop(connChan chan ConnectionEvent) {
282 // create a separate API channel for health check probes
283 ch, err := c.newAPIChannel(1, 1)
285 log.Error("Failed to create health check API channel, health check will be disabled:", err)
290 sinceLastReply time.Duration
294 // send health check probes until an error or timeout occurs
296 // sleep until next health check probe period
297 time.Sleep(HealthCheckProbeInterval)
299 if atomic.LoadUint32(&c.vppConnected) == 0 {
300 // Disconnect has been called in the meantime, return the healthcheck - reconnect loop
301 log.Debug("Disconnected on request, exiting health check loop.")
305 // try draining probe replies from previous request before sending next one
308 log.Debug("drained old probe reply from reply channel")
312 // send the control ping request
313 ch.reqChan <- &vppRequest{msg: msgControlPing}
316 // expect response within timeout period
318 case vppReply := <-ch.replyChan:
321 case <-time.After(HealthCheckReplyTimeout):
322 err = ErrProbeTimeout
324 // check if time since last reply from any other
325 // channel is less than health check reply timeout
326 c.lastReplyLock.Lock()
327 sinceLastReply = time.Since(c.lastReply)
328 c.lastReplyLock.Unlock()
330 if sinceLastReply < HealthCheckReplyTimeout {
331 log.Warnf("VPP health check probe timing out, but some request on other channel was received %v ago, continue waiting!", sinceLastReply)
338 if err == ErrProbeTimeout {
340 log.Warnf("VPP health check probe timed out after %v (%d. timeout)", HealthCheckReplyTimeout, failedChecks)
341 if failedChecks > HealthCheckThreshold {
342 // in case of exceeded failed check treshold, assume VPP disconnected
343 log.Errorf("VPP health check exceeded treshold for timeouts (>%d), assuming disconnect", HealthCheckThreshold)
344 connChan <- ConnectionEvent{Timestamp: time.Now(), State: Disconnected}
347 } else if err != nil {
348 // in case of error, assume VPP disconnected
349 log.Errorf("VPP health check probe failed: %v", err)
350 connChan <- ConnectionEvent{Timestamp: time.Now(), State: Disconnected, Error: err}
352 } else if failedChecks > 0 {
353 // in case of success after failed checks, clear failed check counter
355 log.Infof("VPP health check probe OK")
363 // we are now disconnected, start connect loop
364 c.connectLoop(connChan)
367 func getMsgNameWithCrc(x api.Message) string {
368 return x.GetMessageName() + "_" + x.GetCrcString()
371 func getMsgFactory(msg api.Message) func() api.Message {
372 return func() api.Message {
373 return reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message)
377 // GetMessageID returns message identifier of given API message.
378 func (c *Connection) GetMessageID(msg api.Message) (uint16, error) {
380 return 0, errors.New("nil connection passed in")
383 if msgID, ok := c.msgIDs[getMsgNameWithCrc(msg)]; ok {
387 msgID, err := c.vppClient.GetMsgID(msg.GetMessageName(), msg.GetCrcString())
392 c.msgIDs[getMsgNameWithCrc(msg)] = msgID
393 c.msgMap[msgID] = msg
398 // LookupByID looks up message name and crc by ID.
399 func (c *Connection) LookupByID(msgID uint16) (api.Message, error) {
401 return nil, errors.New("nil connection passed in")
404 if msg, ok := c.msgMap[msgID]; ok {
408 return nil, fmt.Errorf("unknown message ID: %d", msgID)
411 // retrieveMessageIDs retrieves IDs for all registered messages and stores them in map
412 func (c *Connection) retrieveMessageIDs() (err error) {
415 msgs := api.GetRegisteredMessages()
418 for name, msg := range msgs {
419 msgID, err := c.GetMessageID(msg)
421 log.Debugf("retrieving msgID for %s failed: %v", name, err)
426 if c.pingReqID == 0 && msg.GetMessageName() == msgControlPing.GetMessageName() {
428 msgControlPing = reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message)
429 } else if c.pingReplyID == 0 && msg.GetMessageName() == msgControlPingReply.GetMessageName() {
430 c.pingReplyID = msgID
431 msgControlPingReply = reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message)
435 log.Debugf("message %q (%s) has ID: %d", name, getMsgNameWithCrc(msg), msgID)
438 log.Debugf("retrieved %d/%d msgIDs (took %s)", n, len(msgs), time.Since(t))