prevent go routine managing reconnects to leak on fsm stop

protocols/bgp/server/fsm.go

 package server
 
 import (
+	"context"
 	"fmt"
+	"io"
 	"net"
 	"sync"
 	"time"
@@ -70,6 +72,8 @@ type FSM struct {
 	stateMu    sync.RWMutex
 	reason     string
 	active     bool
+
+	connectionCancelFunc context.CancelFunc
 }
 
 // NewPassiveFSM2 initiates a new passive FSM
@@ -105,8 +109,11 @@ func newFSM2(peer *peer) *FSM {
 }
 
 func (fsm *FSM) start() {
+	ctx, cancel := context.WithCancel(context.Background())
+	fsm.connectionCancelFunc = cancel
+
 	go fsm.run()
-	go fsm.tcpConnector()
+	go fsm.tcpConnector(ctx)
 	return
 }
 
@@ -115,6 +122,8 @@ func (fsm *FSM) activate() {
 }
 
 func (fsm *FSM) run() {
+	defer fsm.cancelRunningGoRoutines()
+
 	next, reason := fsm.state.run()
 	for {
 		newState := stateName(next)
@@ -141,6 +150,12 @@ func (fsm *FSM) run() {
 	}
 }
 
+func (fsm *FSM) cancelRunningGoRoutines() {
+	if fsm.connectionCancelFunc != nil {
+		fsm.connectionCancelFunc()
+	}
+}
+
 func stateName(s state) string {
 	switch s.(type) {
 	case *idleState:
@@ -166,7 +181,7 @@ func (fsm *FSM) cease() {
 	fsm.eventCh <- Cease
 }
 
-func (fsm *FSM) tcpConnector() error {
+func (fsm *FSM) tcpConnector(ctx context.Context) error {
 	for {
 		select {
 		case <-fsm.initiateCon:
@@ -186,6 +201,8 @@ func (fsm *FSM) tcpConnector() error {
 			case <-time.NewTimer(time.Second * 30).C:
 				c.Close()
 				continue
+			case <-ctx.Done():
+				return nil
 			}
 		}
 	}
@@ -271,6 +288,23 @@ func (fsm *FSM) sendKeepalive() error {
 	return nil
 }
 
+func recvMsg(c net.Conn) (msg []byte, err error) {
+	buffer := make([]byte, packet.MaxLen)
+	_, err = io.ReadFull(c, buffer[0:packet.MinLen])
+	if err != nil {
+		return nil, fmt.Errorf("Read failed: %v", err)
+	}
+
+	l := int(buffer[16])*256 + int(buffer[17])
+	toRead := l
+	_, err = io.ReadFull(c, buffer[packet.MinLen:toRead])
+	if err != nil {
+		return nil, fmt.Errorf("Read failed: %v", err)
+	}
+
+	return buffer, nil
+}
+
 func stopTimer(t *time.Timer) {
 	if !t.Stop() {
 		select {

protocols/bgp/server/server.go

@@ -2,13 +2,11 @@ package server
 
 import (
 	"fmt"
-	"io"
 	"net"
 	"strings"
 	"sync"
 
 	"github.com/bio-routing/bio-rd/config"
-	"github.com/bio-routing/bio-rd/protocols/bgp/packet"
 	"github.com/bio-routing/bio-rd/routingtable/locRIB"
 	log "github.com/sirupsen/logrus"
 )
@@ -125,20 +123,3 @@ func (b *bgpServer) AddPeer(c config.Peer, rib *locRIB.LocRIB) error {
 
 	return nil
 }
-
-func recvMsg(c net.Conn) (msg []byte, err error) {
-	buffer := make([]byte, packet.MaxLen)
-	_, err = io.ReadFull(c, buffer[0:packet.MinLen])
-	if err != nil {
-		return nil, fmt.Errorf("Read failed: %v", err)
-	}
-
-	l := int(buffer[16])*256 + int(buffer[17])
-	toRead := l
-	_, err = io.ReadFull(c, buffer[packet.MinLen:toRead])
-	if err != nil {
-		return nil, fmt.Errorf("Read failed: %v", err)
-	}
-
-	return buffer, nil
-}