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 RequestChanBufSize = 100 // default size of the request channel buffer
34 ReplyChanBufSize = 100 // default size of the reply channel buffer
35 NotificationChanBufSize = 100 // default size of the notification channel buffer
39 HealthCheckProbeInterval = time.Second * 1 // default health check probe interval
40 HealthCheckReplyTimeout = time.Millisecond * 100 // timeout for reply to a health check probe
41 HealthCheckThreshold = 1 // number of failed health checks until the error is reported
42 DefaultReplyTimeout = time.Second * 1 // default timeout for replies from VPP
43 ReconnectInterval = time.Second * 1 // default interval for reconnect attempts
44 MaxReconnectAttempts = 3 // maximum number of reconnect attempts
47 // ConnectionState represents the current state of the connection to VPP.
48 type ConnectionState int
51 // Connected represents state in which the connection has been successfully established.
52 Connected ConnectionState = iota
54 // Disconnected represents state in which the connection has been dropped.
57 // Failed represents state in which the reconnecting failed after exceeding maximum number of attempts.
61 func (s ConnectionState) String() string {
70 return fmt.Sprintf("UnknownState(%d)", s)
74 // ConnectionEvent is a notification about change in the VPP connection state.
75 type ConnectionEvent struct {
76 // Timestamp holds the time when the event has been created.
79 // State holds the new state of the connection at the time when the event has been created.
82 // Error holds error if any encountered.
86 // Connection represents a shared memory connection to VPP via vppAdapter.
87 type Connection struct {
88 vppClient adapter.VppAPI // VPP binary API client
89 //statsClient adapter.StatsAPI // VPP stats API client
91 vppConnected uint32 // non-zero if the adapter is connected to VPP
93 codec *codec.MsgCodec // message codec
94 msgIDs map[string]uint16 // map of message IDs indexed by message name + CRC
95 msgMap map[uint16]api.Message // map of messages indexed by message ID
97 maxChannelID uint32 // maximum used channel ID (the real limit is 2^15, 32-bit is used for atomic operations)
98 channelsLock sync.RWMutex // lock for the channels map
99 channels map[uint16]*Channel // map of all API channels indexed by the channel ID
101 subscriptionsLock sync.RWMutex // lock for the subscriptions map
102 subscriptions map[uint16][]*subscriptionCtx // map od all notification subscriptions indexed by message ID
104 pingReqID uint16 // ID if the ControlPing message
105 pingReplyID uint16 // ID of the ControlPingReply message
107 lastReplyLock sync.Mutex // lock for the last reply
108 lastReply time.Time // time of the last received reply from VPP
111 func newConnection(binapi adapter.VppAPI) *Connection {
114 codec: &codec.MsgCodec{},
115 msgIDs: make(map[string]uint16),
116 msgMap: make(map[uint16]api.Message),
117 channels: make(map[uint16]*Channel),
118 subscriptions: make(map[uint16][]*subscriptionCtx),
120 binapi.SetMsgCallback(c.msgCallback)
124 // Connect connects to VPP API using specified adapter and returns a connection handle.
125 // This call blocks until it is either connected, or an error occurs.
126 // Only one connection attempt will be performed.
127 func Connect(binapi adapter.VppAPI) (*Connection, error) {
128 // create new connection handle
129 c := newConnection(binapi)
131 // blocking attempt to connect to VPP
132 if err := c.connectVPP(); err != nil {
139 // AsyncConnect asynchronously connects to VPP using specified VPP adapter and returns the connection handle
140 // and ConnectionState channel. This call does not block until connection is established, it
141 // returns immediately. The caller is supposed to watch the returned ConnectionState channel for
142 // Connected/Disconnected events. In case of disconnect, the library will asynchronously try to reconnect.
143 func AsyncConnect(binapi adapter.VppAPI) (*Connection, chan ConnectionEvent, error) {
144 // create new connection handle
145 c := newConnection(binapi)
147 // asynchronously attempt to connect to VPP
148 connChan := make(chan ConnectionEvent, NotificationChanBufSize)
149 go c.connectLoop(connChan)
151 return c, connChan, nil
154 // connectVPP performs blocking attempt to connect to VPP.
155 func (c *Connection) connectVPP() error {
156 log.Debug("Connecting to VPP..")
159 if err := c.vppClient.Connect(); err != nil {
163 log.Debugf("Connected to VPP.")
165 if err := c.retrieveMessageIDs(); err != nil {
166 c.vppClient.Disconnect()
167 return fmt.Errorf("VPP is incompatible: %v", err)
170 // store connected state
171 atomic.StoreUint32(&c.vppConnected, 1)
176 // Disconnect disconnects from VPP API and releases all connection-related resources.
177 func (c *Connection) Disconnect() {
182 if c.vppClient != nil {
187 // disconnectVPP disconnects from VPP in case it is connected.
188 func (c *Connection) disconnectVPP() {
189 if atomic.CompareAndSwapUint32(&c.vppConnected, 1, 0) {
190 c.vppClient.Disconnect()
194 func (c *Connection) NewAPIChannel() (api.Channel, error) {
195 return c.newAPIChannel(RequestChanBufSize, ReplyChanBufSize)
198 func (c *Connection) NewAPIChannelBuffered(reqChanBufSize, replyChanBufSize int) (api.Channel, error) {
199 return c.newAPIChannel(reqChanBufSize, replyChanBufSize)
202 // NewAPIChannelBuffered returns a new API channel for communication with VPP via govpp core.
203 // It allows to specify custom buffer sizes for the request and reply Go channels.
204 func (c *Connection) newAPIChannel(reqChanBufSize, replyChanBufSize int) (*Channel, error) {
206 return nil, errors.New("nil connection passed in")
209 // create new channel
210 chID := uint16(atomic.AddUint32(&c.maxChannelID, 1) & 0x7fff)
211 channel := newChannel(chID, c, c.codec, c, reqChanBufSize, replyChanBufSize)
213 // store API channel within the client
214 c.channelsLock.Lock()
215 c.channels[chID] = channel
216 c.channelsLock.Unlock()
218 // start watching on the request channel
219 go c.watchRequests(channel)
224 // releaseAPIChannel releases API channel that needs to be closed.
225 func (c *Connection) releaseAPIChannel(ch *Channel) {
226 log.WithFields(logger.Fields{
228 }).Debug("API channel released")
230 // delete the channel from channels map
231 c.channelsLock.Lock()
232 delete(c.channels, ch.id)
233 c.channelsLock.Unlock()
236 // connectLoop attempts to connect to VPP until it succeeds.
237 // Then it continues with healthCheckLoop.
238 func (c *Connection) connectLoop(connChan chan ConnectionEvent) {
239 reconnectAttempts := 0
241 // loop until connected
243 if err := c.vppClient.WaitReady(); err != nil {
244 log.Warnf("wait ready failed: %v", err)
246 if err := c.connectVPP(); err == nil {
247 // signal connected event
248 connChan <- ConnectionEvent{Timestamp: time.Now(), State: Connected}
250 } else if reconnectAttempts < MaxReconnectAttempts {
252 log.Errorf("connecting failed (attempt %d/%d): %v", reconnectAttempts, MaxReconnectAttempts, err)
253 time.Sleep(ReconnectInterval)
255 connChan <- ConnectionEvent{Timestamp: time.Now(), State: Failed, Error: err}
260 // we are now connected, continue with health check loop
261 c.healthCheckLoop(connChan)
264 // healthCheckLoop checks whether connection to VPP is alive. In case of disconnect,
265 // it continues with connectLoop and tries to reconnect.
266 func (c *Connection) healthCheckLoop(connChan chan ConnectionEvent) {
267 // create a separate API channel for health check probes
268 ch, err := c.newAPIChannel(1, 1)
270 log.Error("Failed to create health check API channel, health check will be disabled:", err)
275 sinceLastReply time.Duration
279 // send health check probes until an error or timeout occurs
281 // sleep until next health check probe period
282 time.Sleep(HealthCheckProbeInterval)
284 if atomic.LoadUint32(&c.vppConnected) == 0 {
285 // Disconnect has been called in the meantime, return the healthcheck - reconnect loop
286 log.Debug("Disconnected on request, exiting health check loop.")
290 // try draining probe replies from previous request before sending next one
293 log.Debug("drained old probe reply from reply channel")
297 // send the control ping request
298 ch.reqChan <- &vppRequest{msg: msgControlPing}
301 // expect response within timeout period
303 case vppReply := <-ch.replyChan:
306 case <-time.After(HealthCheckReplyTimeout):
307 err = ErrProbeTimeout
309 // check if time since last reply from any other
310 // channel is less than health check reply timeout
311 c.lastReplyLock.Lock()
312 sinceLastReply = time.Since(c.lastReply)
313 c.lastReplyLock.Unlock()
315 if sinceLastReply < HealthCheckReplyTimeout {
316 log.Warnf("VPP health check probe timing out, but some request on other channel was received %v ago, continue waiting!", sinceLastReply)
323 if err == ErrProbeTimeout {
325 log.Warnf("VPP health check probe timed out after %v (%d. timeout)", HealthCheckReplyTimeout, failedChecks)
326 if failedChecks > HealthCheckThreshold {
327 // in case of exceeded failed check treshold, assume VPP disconnected
328 log.Errorf("VPP health check exceeded treshold for timeouts (>%d), assuming disconnect", HealthCheckThreshold)
329 connChan <- ConnectionEvent{Timestamp: time.Now(), State: Disconnected}
332 } else if err != nil {
333 // in case of error, assume VPP disconnected
334 log.Errorf("VPP health check probe failed: %v", err)
335 connChan <- ConnectionEvent{Timestamp: time.Now(), State: Disconnected, Error: err}
337 } else if failedChecks > 0 {
338 // in case of success after failed checks, clear failed check counter
340 log.Infof("VPP health check probe OK")
348 // we are now disconnected, start connect loop
349 c.connectLoop(connChan)
352 func getMsgNameWithCrc(x api.Message) string {
353 return x.GetMessageName() + "_" + x.GetCrcString()
356 func getMsgFactory(msg api.Message) func() api.Message {
357 return func() api.Message {
358 return reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message)
362 // GetMessageID returns message identifier of given API message.
363 func (c *Connection) GetMessageID(msg api.Message) (uint16, error) {
365 return 0, errors.New("nil connection passed in")
368 if msgID, ok := c.msgIDs[getMsgNameWithCrc(msg)]; ok {
372 msgID, err := c.vppClient.GetMsgID(msg.GetMessageName(), msg.GetCrcString())
377 c.msgIDs[getMsgNameWithCrc(msg)] = msgID
378 c.msgMap[msgID] = msg
383 // LookupByID looks up message name and crc by ID.
384 func (c *Connection) LookupByID(msgID uint16) (api.Message, error) {
386 return nil, errors.New("nil connection passed in")
389 if msg, ok := c.msgMap[msgID]; ok {
393 return nil, fmt.Errorf("unknown message ID: %d", msgID)
396 // retrieveMessageIDs retrieves IDs for all registered messages and stores them in map
397 func (c *Connection) retrieveMessageIDs() (err error) {
400 msgs := api.GetRegisteredMessages()
403 for name, msg := range msgs {
404 msgID, err := c.GetMessageID(msg)
406 log.Debugf("retrieving msgID for %s failed: %v", name, err)
411 if c.pingReqID == 0 && msg.GetMessageName() == msgControlPing.GetMessageName() {
413 msgControlPing = reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message)
414 } else if c.pingReplyID == 0 && msg.GetMessageName() == msgControlPingReply.GetMessageName() {
415 c.pingReplyID = msgID
416 msgControlPingReply = reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message)
420 log.Debugf("message %q (%s) has ID: %d", name, getMsgNameWithCrc(msg), msgID)
423 log.Debugf("retrieved %d/%d msgIDs (took %s)", n, len(msgs), time.Since(t))