pan: expose scmpHandler (#266)

* expose scmpHandler * change to functional options pattern * ignore nil opts * fix API calls * pass
netsec-ethz · Feb 11, 2025 · 1e300df · 1e300df
1 parent f70181a
commit 1e300df
Show file tree

Hide file tree

Showing 24 changed files with 163 additions and 63 deletions.
diff --git a/_examples/helloquic/helloquic.go b/_examples/helloquic/helloquic.go
@@ -57,7 +57,7 @@ func runServer(listen netip.AddrPort) error {
 		Certificates: quicutil.MustGenerateSelfSignedCert(),
 		NextProtos:   []string{"hello-quic"},
 	}
-	listener, err := pan.ListenQUIC(context.Background(), listen, nil, tlsCfg, nil)
+	listener, err := pan.ListenQUIC(context.Background(), listen, tlsCfg, nil)
 	if err != nil {
 		return err
 	}
@@ -119,7 +119,7 @@ func runClient(address string, count int) error {
 		Timeout:  time.Second,
 	}
 	selector.SetActive(2)
-	session, err := pan.DialQUIC(context.Background(), netip.AddrPort{}, addr, nil, selector, "", tlsCfg, nil)
+	session, err := pan.DialQUIC(context.Background(), netip.AddrPort{}, addr, "", tlsCfg, nil, pan.WithSelector(selector))
 	if err != nil {
 		return err
 	}

diff --git a/_examples/helloworld/helloworld.go b/_examples/helloworld/helloworld.go
@@ -49,7 +49,7 @@ func main() {
 }
 
 func runServer(listen netip.AddrPort) error {
-	conn, err := pan.ListenUDP(context.Background(), listen, nil)
+	conn, err := pan.ListenUDP(context.Background(), listen)
 	if err != nil {
 		return err
 	}
@@ -78,7 +78,7 @@ func runClient(address string, count int) error {
 	if err != nil {
 		return err
 	}
-	conn, err := pan.DialUDP(context.Background(), netip.AddrPort{}, addr, nil, nil)
+	conn, err := pan.DialUDP(context.Background(), netip.AddrPort{}, addr)
 	if err != nil {
 		return err
 	}

diff --git a/_examples/sgrpc/client/main.go b/_examples/sgrpc/client/main.go
@@ -32,7 +32,7 @@ func NewPanQuicDialer(tlsCfg *tls.Config) func(context.Context, string) (net.Con
 		}
 
 		clientQuicConfig := &quic.Config{KeepAlivePeriod: 15 * time.Second}
-		session, err := pan.DialQUIC(ctx, netip.AddrPort{}, panAddr, nil, nil, "", tlsCfg, clientQuicConfig)
+		session, err := pan.DialQUIC(ctx, netip.AddrPort{}, panAddr, "", tlsCfg, clientQuicConfig)
 		if err != nil {
 			return nil, fmt.Errorf("did not dial: %w", err)
 		}

diff --git a/_examples/sgrpc/server/main.go b/_examples/sgrpc/server/main.go
@@ -49,7 +49,7 @@ func main() {
 		NextProtos:   []string{"echo_service"},
 	}
 
-	quicListener, err := pan.ListenQUIC(context.Background(), addr, nil, tlsCfg, nil)
+	quicListener, err := pan.ListenQUIC(context.Background(), addr, tlsCfg, nil)
 	if err != nil {
 		log.Fatalf("failed to listen SCION QUIC on %s: %v", *ServerAddr, err)
 	}

diff --git a/bwtester/bwtestclient/bwtestclient.go b/bwtester/bwtestclient/bwtestclient.go
@@ -335,7 +335,7 @@ func runBwtest(local netip.AddrPort, serverCCAddr pan.UDPAddr, policy pan.Policy
 
 	// Control channel connection
 	ccSelector := pan.NewDefaultSelector()
-	ccConn, err := pan.DialUDP(context.Background(), local, serverCCAddr, policy, ccSelector)
+	ccConn, err := pan.DialUDP(context.Background(), local, serverCCAddr, pan.WithPolicy(policy), pan.WithSelector(ccSelector))
 	if err != nil {
 		return
 	}
@@ -345,7 +345,7 @@ func runBwtest(local netip.AddrPort, serverCCAddr pan.UDPAddr, policy pan.Policy
 	serverDCAddr := serverCCAddr.WithPort(serverCCAddr.Port + 1)
 
 	// Data channel connection
-	dcConn, err := pan.DialUDP(context.Background(), dcLocal, serverDCAddr, policy, nil)
+	dcConn, err := pan.DialUDP(context.Background(), dcLocal, serverDCAddr, pan.WithPolicy(policy))
 	if err != nil {
 		return
 	}

diff --git a/bwtester/bwtestserver/bwtestserver.go b/bwtester/bwtestserver/bwtestserver.go
@@ -52,7 +52,7 @@ func runServer(listen netip.AddrPort) error {
 	results := make(resultsMap)
 
 	ccSelector := pan.NewDefaultReplySelector()
-	ccConn, err := pan.ListenUDP(context.Background(), listen, ccSelector)
+	ccConn, err := pan.ListenUDP(context.Background(), listen, pan.WithReplySelector(ccSelector))
 	if err != nil {
 		return err
 	}
@@ -287,7 +287,7 @@ func (r resultsMap) purgeExpired() {
 }
 
 func listenConnected(local netip.AddrPort, remote pan.UDPAddr, selector pan.ReplySelector) (net.Conn, error) {
-	conn, err := pan.ListenUDP(context.Background(), local, selector)
+	conn, err := pan.ListenUDP(context.Background(), local, pan.WithReplySelector(selector))
 	return connectedPacketConn{
 		ListenConn: conn,
 		remote:     remote,

diff --git a/netcat/quic.go b/netcat/quic.go
@@ -36,7 +36,6 @@ func DoListenQUIC(port uint16) (chan io.ReadWriteCloser, error) {
 	quicListener, err := pan.ListenQUIC(
 		context.Background(),
 		netip.AddrPortFrom(netip.Addr{}, port),
-		nil,
 		&tls.Config{
 			Certificates: quicutil.MustGenerateSelfSignedCert(),
 			NextProtos:   nextProtos,
@@ -74,14 +73,13 @@ func DoDialQUIC(remote string, policy pan.Policy) (io.ReadWriteCloser, error) {
 		context.Background(),
 		netip.AddrPort{},
 		remoteAddr,
-		policy,
-		nil,
 		pan.MangleSCIONAddr(remote),
 		&tls.Config{
 			InsecureSkipVerify: true,
 			NextProtos:         nextProtos,
 		},
 		&quic.Config{KeepAlivePeriod: 15 * time.Second},
+		pan.WithPolicy(policy),
 	)
 	if err != nil {
 		return nil, err

diff --git a/netcat/udp.go b/netcat/udp.go
@@ -58,7 +58,7 @@ func DoDialUDP(remote string, policy pan.Policy) (io.ReadWriteCloser, error) {
 	if err != nil {
 		return nil, err
 	}
-	conn, err := pan.DialUDP(context.Background(), netip.AddrPort{}, remoteAddr, policy, nil)
+	conn, err := pan.DialUDP(context.Background(), netip.AddrPort{}, remoteAddr, pan.WithPolicy(policy))
 	if err != nil {
 		return nil, err
 	}
@@ -71,7 +71,6 @@ func DoListenUDP(port uint16) (chan io.ReadWriteCloser, error) {
 	conn, err := pan.ListenUDP(
 		context.Background(),
 		netip.AddrPortFrom(netip.Addr{}, port),
-		nil,
 	)
 	if err != nil {
 		return nil, err

diff --git a/pkg/pan/quic_dial.go b/pkg/pan/quic_dial.go
@@ -52,11 +52,17 @@ func (s *QUICEarlySession) CloseWithError(code quic.ApplicationErrorCode, desc s
 //
 // The host parameter is used for SNI.
 // The tls.Config must define an application protocol (using NextProtos).
-func DialQUIC(ctx context.Context,
-	local netip.AddrPort, remote UDPAddr, policy Policy, selector Selector,
-	host string, tlsConf *tls.Config, quicConf *quic.Config) (*QUICSession, error) {
-
-	conn, err := DialUDP(ctx, local, remote, policy, selector)
+func DialQUIC(
+	ctx context.Context,
+	local netip.AddrPort,
+	remote UDPAddr,
+	host string,
+	tlsConf *tls.Config,
+	quicConf *quic.Config,
+	connOptions ...ConnOptions,
+) (*QUICSession, error) {
+
+	conn, err := DialUDP(ctx, local, remote, connOptions...)
 	if err != nil {
 		return nil, err
 	}
@@ -87,11 +93,17 @@ func DialQUIC(ctx context.Context,
 }
 
 // DialQUICEarly establishes a new 0-RTT QUIC connection to a server. Analogous to DialQUIC.
-func DialQUICEarly(ctx context.Context,
-	local netip.AddrPort, remote UDPAddr, policy Policy, selector Selector,
-	host string, tlsConf *tls.Config, quicConf *quic.Config) (*QUICEarlySession, error) {
-
-	conn, err := DialUDP(ctx, local, remote, policy, selector)
+func DialQUICEarly(
+	ctx context.Context,
+	local netip.AddrPort,
+	remote UDPAddr,
+	host string,
+	tlsConf *tls.Config,
+	quicConf *quic.Config,
+	connOptions ...ConnOptions,
+) (*QUICEarlySession, error) {
+
+	conn, err := DialUDP(ctx, local, remote, connOptions...)
 	if err != nil {
 		return nil, err
 	}

diff --git a/pkg/pan/quic_listen.go b/pkg/pan/quic_listen.go
@@ -40,10 +40,15 @@ func (l *QUICListener) Close() error {
 // ListenQUIC listens for QUIC connections on a SCION/UDP port.
 //
 // See note on wildcard addresses in the package documentation.
-func ListenQUIC(ctx context.Context, local netip.AddrPort, selector ReplySelector,
-	tlsConf *tls.Config, quicConfig *quic.Config) (*QUICListener, error) {
+func ListenQUIC(
+	ctx context.Context,
+	local netip.AddrPort,
+	tlsConf *tls.Config,
+	quicConfig *quic.Config,
+	listenConnOptions ...ListenConnOptions,
+) (*QUICListener, error) {
 
-	conn, err := ListenUDP(ctx, local, selector)
+	conn, err := ListenUDP(ctx, local, listenConnOptions...)
 	if err != nil {
 		return nil, err
 	}

diff --git a/pkg/pan/raw.go b/pkg/pan/raw.go
@@ -152,9 +152,9 @@ func (c *baseUDPConn) Close() error {
 	return c.raw.Close()
 }
 
-type scmpHandler struct{}
+type DefaultSCMPHandler struct{}
 
-func (h scmpHandler) Handle(pkt *snet.Packet) error {
+func (h DefaultSCMPHandler) Handle(pkt *snet.Packet) error {
 	scmp := pkt.Payload.(snet.SCMPPayload)
 	switch scmp.Type() {
 	case slayers.SCMPTypeExternalInterfaceDown:

diff --git a/pkg/pan/udp_dial.go b/pkg/pan/udp_dial.go
@@ -47,17 +47,20 @@ type Conn interface {
 // a path among this set for each Write operation.
 // If the policy is nil, all paths are allowed.
 // If the selector is nil, a DefaultSelector is used.
-func DialUDP(ctx context.Context, local netip.AddrPort, remote UDPAddr,
-	policy Policy, selector Selector) (Conn, error) {
-
+func DialUDP(
+	ctx context.Context,
+	local netip.AddrPort,
+	remote UDPAddr,
+	opts ...ConnOptions,
+) (Conn, error) {
+	o := applyConnOpts(opts)
 	local, err := defaultLocalAddr(local)
 	if err != nil {
 		return nil, err
 	}
-
 	sn := snet.SCIONNetwork{
 		Topology:    host().sciond,
-		SCMPHandler: scmpHandler{},
+		SCMPHandler: o.scmpHandler,
 	}
 	conn, err := sn.OpenRaw(ctx, net.UDPAddrFromAddrPort(local))
 	if err != nil {
@@ -71,10 +74,7 @@ func DialUDP(ctx context.Context, local netip.AddrPort, remote UDPAddr,
 	}
 	var subscriber *pathRefreshSubscriber
 	if remote.IA != localUDPAddr.IA {
-		if selector == nil {
-			selector = NewDefaultSelector()
-		}
-		subscriber, err = openPathRefreshSubscriber(ctx, localUDPAddr, remote, policy, selector)
+		subscriber, err = openPathRefreshSubscriber(ctx, localUDPAddr, remote, o.policy, o.selector)
 		if err != nil {
 			return nil, err
 		}
@@ -86,10 +86,58 @@ func DialUDP(ctx context.Context, local netip.AddrPort, remote UDPAddr,
 		local:      localUDPAddr,
 		remote:     remote,
 		subscriber: subscriber,
-		selector:   selector,
+		selector:   o.selector,
 	}, nil
 }
 
+type ConnOptions func(*connOptions)
+
+// WithDialSCMPHandler sets the SCMP handler for the connection.
+func WithDialSCMPHandler(handler snet.SCMPHandler) ConnOptions {
+	return func(o *connOptions) {
+		if handler == nil {
+			panic("nil SCMP handler not allowed")
+		}
+		o.scmpHandler = handler
+	}
+}
+
+// WithSelector sets the path selector for the connection.
+func WithSelector(selector Selector) ConnOptions {
+	return func(o *connOptions) {
+		if selector == nil {
+			panic("nil selector not allowed")
+		}
+		o.selector = selector
+	}
+}
+
+// WithPolicy sets the path policy for the connection.
+func WithPolicy(policy Policy) ConnOptions {
+	return func(o *connOptions) {
+		o.policy = policy
+	}
+}
+
+type connOptions struct {
+	scmpHandler snet.SCMPHandler
+	selector    Selector
+	policy      Policy
+}
+
+func applyConnOpts(opts []ConnOptions) connOptions {
+	o := connOptions{
+		scmpHandler: DefaultSCMPHandler{},
+		selector:    NewDefaultSelector(),
+	}
+	for _, opt := range opts {
+		if opt != nil {
+			opt(&o)
+		}
+	}
+	return o
+}
+
 type dialedConn struct {
 	baseUDPConn
 
@@ -110,9 +158,6 @@ func (c *dialedConn) LocalAddr() net.Addr {
 }
 
 func (c *dialedConn) GetPath() *Path {
-	if c.selector == nil {
-		return nil
-	}
 	return c.selector.Path()
 }