remove duplicated use of the context in ConnectN4()

internal/pfcpsim/helpers.go

@@ -4,7 +4,6 @@
 package pfcpsim
 
 import (
-	"context"
 	"errors"
 	"fmt"
 	"net"
@@ -39,15 +38,11 @@ func ConnectPFCPSim() error {
 		sim = pfcpsim.NewPFCPClient(localAddr.String())
 	}
 
-	ctx, cancel := context.WithCancel(context.Background())
-
-	err := sim.ConnectN4(ctx, remotePeerAddress)
+	err := sim.ConnectN4(remotePeerAddress)
 	if err != nil {
-		cancel()
 		return err
 	}
 
-	cancelFunc = cancel
 	remotePeerConnected = true
 
 	return nil
@@ -58,9 +53,7 @@ func DisconnectPFCPSim() error {
 		return notInit
 	}
 
-	cancelFunc()
-
-	return nil
+	return sim.TeardownAssociation()
 }
 
 func isConfigured() bool {

internal/pfcpsim/state.go

@@ -4,8 +4,6 @@
 package pfcpsim
 
 import (
-	"context"
-
 	"github.com/omec-project/pfcpsim/pkg/pfcpsim"
 )
 
@@ -18,5 +16,4 @@ var (
 	// Emulates 5G SMF/ 4G SGW
 	sim                 *pfcpsim.PFCPClient
 	remotePeerConnected bool
-	cancelFunc          context.CancelFunc
 )

pkg/pfcpsim/pfcpsim.go

@@ -85,8 +85,8 @@ type PFCPClient struct {
 	aliveLock           sync.Mutex
 	isAssociationActive bool
 
-	ctx              context.Context
-	cancelHeartbeats context.CancelFunc
+	ctx    context.Context
+	cancel context.CancelFunc
 
 	heartbeatsChan chan *message.HeartbeatResponse
 	recvChan       chan message.Message
@@ -109,7 +109,9 @@ func NewPFCPClient(localAddr string) *PFCPClient {
 		responseTimeout: DefaultResponseTimeout,
 	}
 
-	client.ctx = context.Background()
+	ctx, cancelFunc := context.WithCancel(context.Background())
+	client.ctx = ctx
+	client.cancel = cancelFunc
 	client.heartbeatsChan = make(chan *message.HeartbeatResponse)
 	client.recvChan = make(chan message.Message)
 
@@ -166,21 +168,12 @@ func (c *PFCPClient) sendMsg(msg message.Message) error {
 	return nil
 }
 
-func (c *PFCPClient) receiveFromN4(ctx context.Context) {
+func (c *PFCPClient) receiveFromN4() {
 	buf := make([]byte, 3000)
 
 	for {
 		select {
-		case <-ctx.Done():
-			if c.cancelHeartbeats != nil {
-				c.cancelHeartbeats()
-			}
-
-			err := c.conn.Close()
-			if err != nil {
-				fmt.Println(err)
-			}
-
+		case <-c.ctx.Done():
 			return
 		default:
 			n, _, err := c.conn.ReadFrom(buf)
@@ -210,7 +203,7 @@ func (c *PFCPClient) receiveFromN4(ctx context.Context) {
 	}
 }
 
-func (c *PFCPClient) ConnectN4(ctx context.Context, remoteAddr string) error {
+func (c *PFCPClient) ConnectN4(remoteAddr string) error {
 	addr := fmt.Sprintf("%s:%d", remoteAddr, PFCPStandardPort)
 
 	if host, port, err := net.SplitHostPort(remoteAddr); err == nil {
@@ -232,14 +225,15 @@ func (c *PFCPClient) ConnectN4(ctx context.Context, remoteAddr string) error {
 
 	c.conn = rxconn
 
-	go c.receiveFromN4(ctx)
+	go c.receiveFromN4()
 
 	return nil
 }
 
 func (c *PFCPClient) DisconnectN4() {
-	if c.cancelHeartbeats != nil {
-		c.cancelHeartbeats()
+	if c.cancel != nil {
+		c.cancel()
+		c.cancel = nil
 	}
 
 	err := c.conn.Close()
@@ -330,8 +324,13 @@ func (c *PFCPClient) SendAssociationSetupRequest(ie ...*ieLib.IE) error {
 // SendAssociationTeardownRequest sends PFCP Teardown Request towards a peer.
 // A caller should make sure that the PFCP connection is established before invoking this function.
 func (c *PFCPClient) SendAssociationTeardownRequest(ie ...*ieLib.IE) error {
+	raddr, err := net.ResolveUDPAddr("udp", c.remoteAddr)
+	if err != nil {
+		return err
+	}
+
 	teardownReq := message.NewAssociationReleaseRequest(0,
-		ieLib.NewNodeID(c.conn.RemoteAddr().String(), "", ""),
+		ieLib.NewNodeID(raddr.String(), "", ""),
 	)
 
 	teardownReq.IEs = append(teardownReq.IEs, ie...)
@@ -400,12 +399,12 @@ func (c *PFCPClient) SendSessionDeletionRequest(localSEID uint64, remoteSEID uin
 	return c.sendMsg(delReq)
 }
 
-func (c *PFCPClient) StartHeartbeats(stopCtx context.Context) {
+func (c *PFCPClient) StartHeartbeats() {
 	ticker := time.NewTicker(DefaultHeartbeatPeriod * time.Second)
 
 	for {
 		select {
-		case <-stopCtx.Done():
+		case <-c.ctx.Done():
 			return
 		case <-ticker.C:
 			err := c.SendAndRecvHeartbeat()
@@ -460,12 +459,9 @@ func (c *PFCPClient) SetupAssociation() error {
 		return NewInvalidResponseError(assocFailed)
 	}
 
-	ctx, cancelFunc := context.WithCancel(c.ctx)
-	c.cancelHeartbeats = cancelFunc
-
 	c.setAssociationStatus(true)
 
-	go c.StartHeartbeats(ctx)
+	go c.StartHeartbeats()
 
 	return nil
 }
@@ -498,8 +494,9 @@ func (c *PFCPClient) TeardownAssociation() error {
 		return NewInvalidResponseError()
 	}
 
-	if c.cancelHeartbeats != nil {
-		c.cancelHeartbeats()
+	if c.cancel != nil {
+		c.cancel()
+		c.cancel = nil
 	}
 
 	c.setAssociationStatus(false)