X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=core%2Fchannel.go;h=a7d95fe1ecda271b622e58b2dc699af146224bac;hb=56e997fc27c775790fcce5eda92bb2baee82d881;hp=87b3e29a1f41c40b727ce80e42335f18d91ac21e;hpb=f1bef4a3c66f4408afdeb64cda62ccd8562d0fc6;p=govpp.git diff --git a/core/channel.go b/core/channel.go index 87b3e29..a7d95fe 100644 --- a/core/channel.go +++ b/core/channel.go @@ -15,166 +15,231 @@ package core import ( + "errors" "fmt" + "reflect" + "strings" "time" - "errors" - "git.fd.io/govpp.git/api" "github.com/sirupsen/logrus" ) -const defaultReplyTimeout = time.Second * 1 // default timeout for replies from VPP, can be changed with SetReplyTimeout +var ( + ErrInvalidRequestCtx = errors.New("invalid request context") +) -// requestCtxData is a context of a ongoing request (simple one - only one response is expected). -type requestCtxData struct { - ch *channel - seqNum uint16 +// MessageCodec provides functionality for decoding binary data to generated API messages. +type MessageCodec interface { + //EncodeMsg encodes message into binary data. + EncodeMsg(msg api.Message, msgID uint16) ([]byte, error) + // DecodeMsg decodes binary-encoded data of a message into provided Message structure. + DecodeMsg(data []byte, msg api.Message) error } -// multiRequestCtxData is a context of a ongoing multipart request (multiple responses are expected). -type multiRequestCtxData struct { - ch *channel - seqNum uint16 +// MessageIdentifier provides identification of generated API messages. +type MessageIdentifier interface { + // GetMessageID returns message identifier of given API message. + GetMessageID(msg api.Message) (uint16, error) + // LookupByID looks up message name and crc by ID + LookupByID(msgID uint16) (api.Message, error) } -func (req *requestCtxData) ReceiveReply(msg api.Message) error { - if req == nil || req.ch == nil { - return errors.New("invalid request context") - } +// vppRequest is a request that will be sent to VPP. +type vppRequest struct { + seqNum uint16 // sequence number + msg api.Message // binary API message to be send to VPP + multi bool // true if multipart response is expected +} - lastReplyReceived, err := req.ch.receiveReplyInternal(msg, req.seqNum) +// vppReply is a reply received from VPP. +type vppReply struct { + seqNum uint16 // sequence number + msgID uint16 // ID of the message + data []byte // encoded data with the message + lastReceived bool // for multi request, true if the last reply has been already received + err error // in case of error, data is nil and this member contains error +} - if lastReplyReceived { - err = errors.New("multipart reply recieved while a simple reply expected") - } - return err +// requestCtx is a context for request with single reply +type requestCtx struct { + ch *Channel + seqNum uint16 } -func (req *multiRequestCtxData) ReceiveReply(msg api.Message) (lastReplyReceived bool, err error) { - if req == nil || req.ch == nil { - return false, errors.New("invalid request context") - } +// multiRequestCtx is a context for request with multiple responses +type multiRequestCtx struct { + ch *Channel + seqNum uint16 +} - return req.ch.receiveReplyInternal(msg, req.seqNum) +// subscriptionCtx is a context of subscription for delivery of specific notification messages. +type subscriptionCtx struct { + ch *Channel + notifChan chan api.Message // channel where notification messages will be delivered to + msgID uint16 // message ID for the subscribed event message + event api.Message // event message that this subscription is for + msgFactory func() api.Message // function that returns a new instance of the specific message that is expected as a notification } // channel is the main communication interface with govpp core. It contains four Go channels, one for sending the requests // to VPP, one for receiving the replies from it and the same set for notifications. The user can access the Go channels // via methods provided by Channel interface in this package. Do not use the same channel from multiple goroutines // concurrently, otherwise the responses could mix! Use multiple channels instead. -type channel struct { - id uint16 // channel ID - - reqChan chan *api.VppRequest // channel for sending the requests to VPP, closing this channel releases all resources in the ChannelProvider - replyChan chan *api.VppReply // channel where VPP replies are delivered to +type Channel struct { + id uint16 + conn *Connection - notifSubsChan chan *api.NotifSubscribeRequest // channel for sending notification subscribe requests - notifSubsReplyChan chan error // channel where replies to notification subscribe requests are delivered to + reqChan chan *vppRequest // channel for sending the requests to VPP + replyChan chan *vppReply // channel where VPP replies are delivered to - msgDecoder api.MessageDecoder // used to decode binary data to generated API messages - msgIdentifier api.MessageIdentifier // used to retrieve message ID of a message + msgCodec MessageCodec // used to decode binary data to generated API messages + msgIdentifier MessageIdentifier // used to retrieve message ID of a message lastSeqNum uint16 // sequence number of the last sent request - delayedReply *api.VppReply // reply already taken from ReplyChan, buffered for later delivery + delayedReply *vppReply // reply already taken from ReplyChan, buffered for later delivery replyTimeout time.Duration // maximum time that the API waits for a reply from VPP before returning an error, can be set with SetReplyTimeout } -func (ch *channel) SendRequest(msg api.Message) api.RequestCtx { - ch.lastSeqNum++ - ch.reqChan <- &api.VppRequest{ - Message: msg, - SeqNum: ch.lastSeqNum, +func newChannel(id uint16, conn *Connection, codec MessageCodec, identifier MessageIdentifier, reqSize, replySize int) *Channel { + return &Channel{ + id: id, + conn: conn, + msgCodec: codec, + msgIdentifier: identifier, + reqChan: make(chan *vppRequest, reqSize), + replyChan: make(chan *vppReply, replySize), + replyTimeout: DefaultReplyTimeout, } - return &requestCtxData{ch: ch, seqNum: ch.lastSeqNum} } -func (ch *channel) SendMultiRequest(msg api.Message) api.MultiRequestCtx { +func (ch *Channel) GetID() uint16 { + return ch.id +} + +func (ch *Channel) nextSeqNum() uint16 { ch.lastSeqNum++ - ch.reqChan <- &api.VppRequest{ - Message: msg, - Multipart: true, - SeqNum: ch.lastSeqNum, - } - return &multiRequestCtxData{ch: ch, seqNum: ch.lastSeqNum} + return ch.lastSeqNum } -func (ch *channel) SubscribeNotification(notifChan chan api.Message, msgFactory func() api.Message) (*api.NotifSubscription, error) { - subscription := &api.NotifSubscription{ - NotifChan: notifChan, - MsgFactory: msgFactory, +func (ch *Channel) SendRequest(msg api.Message) api.RequestCtx { + seqNum := ch.nextSeqNum() + ch.reqChan <- &vppRequest{ + msg: msg, + seqNum: seqNum, } - ch.notifSubsChan <- &api.NotifSubscribeRequest{ - Subscription: subscription, - Subscribe: true, + return &requestCtx{ch: ch, seqNum: seqNum} +} + +func (ch *Channel) SendMultiRequest(msg api.Message) api.MultiRequestCtx { + seqNum := ch.nextSeqNum() + ch.reqChan <- &vppRequest{ + msg: msg, + seqNum: seqNum, + multi: true, } - return subscription, <-ch.notifSubsReplyChan + return &multiRequestCtx{ch: ch, seqNum: seqNum} } -func (ch *channel) UnsubscribeNotification(subscription *api.NotifSubscription) error { - ch.notifSubsChan <- &api.NotifSubscribeRequest{ - Subscription: subscription, - Subscribe: false, +func getMsgFactory(msg api.Message) func() api.Message { + return func() api.Message { + return reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message) } - return <-ch.notifSubsReplyChan } -func (ch *channel) CheckMessageCompatibility(messages ...api.Message) error { - for _, msg := range messages { - _, err := ch.msgIdentifier.GetMessageID(msg) - if err != nil { - return fmt.Errorf("message %s with CRC %s is not compatible with the VPP we are connected to", - msg.GetMessageName(), msg.GetCrcString()) - } +func (ch *Channel) SubscribeNotification(notifChan chan api.Message, event api.Message) (api.SubscriptionCtx, error) { + msgID, err := ch.msgIdentifier.GetMessageID(event) + if err != nil { + log.WithFields(logrus.Fields{ + "msg_name": event.GetMessageName(), + "msg_crc": event.GetCrcString(), + }).Errorf("unable to retrieve message ID: %v", err) + return nil, fmt.Errorf("unable to retrieve event message ID: %v", err) } - return nil + + sub := &subscriptionCtx{ + ch: ch, + notifChan: notifChan, + msgID: msgID, + event: event, + msgFactory: getMsgFactory(event), + } + + // add the subscription into map + ch.conn.subscriptionsLock.Lock() + defer ch.conn.subscriptionsLock.Unlock() + + ch.conn.subscriptions[msgID] = append(ch.conn.subscriptions[msgID], sub) + + return sub, nil } -func (ch *channel) SetReplyTimeout(timeout time.Duration) { +func (ch *Channel) SetReplyTimeout(timeout time.Duration) { ch.replyTimeout = timeout } -func (ch *channel) GetRequestChannel() chan<- *api.VppRequest { - return ch.reqChan +func (ch *Channel) Close() { + if ch.reqChan != nil { + close(ch.reqChan) + ch.reqChan = nil + } } -func (ch *channel) GetReplyChannel() <-chan *api.VppReply { - return ch.replyChan -} +func (req *requestCtx) ReceiveReply(msg api.Message) error { + if req == nil || req.ch == nil { + return ErrInvalidRequestCtx + } -func (ch *channel) GetNotificationChannel() chan<- *api.NotifSubscribeRequest { - return ch.notifSubsChan -} + lastReplyReceived, err := req.ch.receiveReplyInternal(msg, req.seqNum) + if err != nil { + return err + } else if lastReplyReceived { + return errors.New("multipart reply recieved while a single reply expected") + } -func (ch *channel) GetNotificationReplyChannel() <-chan error { - return ch.notifSubsReplyChan + return nil } -func (ch *channel) GetMessageDecoder() api.MessageDecoder { - return ch.msgDecoder -} +func (req *multiRequestCtx) ReceiveReply(msg api.Message) (lastReplyReceived bool, err error) { + if req == nil || req.ch == nil { + return false, ErrInvalidRequestCtx + } -func (ch *channel) GetID() uint16 { - return ch.id + return req.ch.receiveReplyInternal(msg, req.seqNum) } -func (ch *channel) Close() { - if ch.reqChan != nil { - close(ch.reqChan) +func (sub *subscriptionCtx) Unsubscribe() error { + log.WithFields(logrus.Fields{ + "msg_name": sub.event.GetMessageName(), + "msg_id": sub.msgID, + }).Debug("Removing notification subscription.") + + // remove the subscription from the map + sub.ch.conn.subscriptionsLock.Lock() + defer sub.ch.conn.subscriptionsLock.Unlock() + + for i, item := range sub.ch.conn.subscriptions[sub.msgID] { + if item == sub { + // remove i-th item in the slice + sub.ch.conn.subscriptions[sub.msgID] = append(sub.ch.conn.subscriptions[sub.msgID][:i], sub.ch.conn.subscriptions[sub.msgID][i+1:]...) + return nil + } } + + return fmt.Errorf("subscription for %q not found", sub.event.GetMessageName()) } // receiveReplyInternal receives a reply from the reply channel into the provided msg structure. -func (ch *channel) receiveReplyInternal(msg api.Message, expSeqNum uint16) (lastReplyReceived bool, err error) { - var ignore bool +func (ch *Channel) receiveReplyInternal(msg api.Message, expSeqNum uint16) (lastReplyReceived bool, err error) { if msg == nil { return false, errors.New("nil message passed in") } - if ch.delayedReply != nil { + var ignore bool + + if vppReply := ch.delayedReply; vppReply != nil { // try the delayed reply - vppReply := ch.delayedReply ch.delayedReply = nil ignore, lastReplyReceived, err = ch.processReply(vppReply, expSeqNum, msg) if !ignore { @@ -201,12 +266,12 @@ func (ch *channel) receiveReplyInternal(msg api.Message, expSeqNum uint16) (last return } -func (ch *channel) processReply(reply *api.VppReply, expSeqNum uint16, msg api.Message) (ignore bool, lastReplyReceived bool, err error) { +func (ch *Channel) processReply(reply *vppReply, expSeqNum uint16, msg api.Message) (ignore bool, lastReplyReceived bool, err error) { // check the sequence number - cmpSeqNums := compareSeqNumbers(reply.SeqNum, expSeqNum) + cmpSeqNums := compareSeqNumbers(reply.seqNum, expSeqNum) if cmpSeqNums == -1 { // reply received too late, ignore the message - logrus.WithField("sequence-number", reply.SeqNum).Warn( + logrus.WithField("seqNum", reply.seqNum).Warn( "Received reply to an already closed binary API request") ignore = true return @@ -217,11 +282,11 @@ func (ch *channel) processReply(reply *api.VppReply, expSeqNum uint16, msg api.M return } - if reply.Error != nil { - err = reply.Error + if reply.err != nil { + err = reply.err return } - if reply.LastReplyReceived { + if reply.lastReceived { lastReplyReceived = true return } @@ -235,42 +300,33 @@ func (ch *channel) processReply(reply *api.VppReply, expSeqNum uint16, msg api.M return } - if reply.MessageID != expMsgID { + if reply.msgID != expMsgID { var msgNameCrc string - if nameCrc, err := ch.msgIdentifier.LookupByID(reply.MessageID); err != nil { + if replyMsg, err := ch.msgIdentifier.LookupByID(reply.msgID); err != nil { msgNameCrc = err.Error() } else { - msgNameCrc = nameCrc + msgNameCrc = getMsgNameWithCrc(replyMsg) } - err = fmt.Errorf("received invalid message ID (seq-num=%d), expected %d (%s), but got %d (%s) "+ + err = fmt.Errorf("received invalid message ID (seqNum=%d), expected %d (%s), but got %d (%s) "+ "(check if multiple goroutines are not sharing single GoVPP channel)", - reply.SeqNum, expMsgID, msg.GetMessageName(), reply.MessageID, msgNameCrc) + reply.seqNum, expMsgID, msg.GetMessageName(), reply.msgID, msgNameCrc) return } // decode the message - err = ch.msgDecoder.DecodeMsg(reply.Data, msg) - return -} - -// compareSeqNumbers returns -1, 0, 1 if sequence number precedes, equals to, -// or succeeds seq. number . -// Since sequence numbers cycle in the finite set of size 2^16, the function -// must assume that the distance between compared sequence numbers is less than -// (2^16)/2 to determine the order. -func compareSeqNumbers(seqNum1, seqNum2 uint16) int { - // calculate distance from seqNum1 to seqNum2 - var dist uint16 - if seqNum1 <= seqNum2 { - dist = seqNum2 - seqNum1 - } else { - dist = 0xffff - (seqNum1 - seqNum2 - 1) + if err = ch.msgCodec.DecodeMsg(reply.data, msg); err != nil { + return } - if dist == 0 { - return 0 - } else if dist <= 0x8000 { - return -1 + + // check Retval and convert it into VnetAPIError error + if strings.HasSuffix(msg.GetMessageName(), "_reply") { + // TODO: use categories for messages to avoid checking message name + if f := reflect.Indirect(reflect.ValueOf(msg)).FieldByName("Retval"); f.IsValid() { + retval := int32(f.Int()) + err = api.RetvalToVPPApiError(retval) + } } - return 1 + + return }