5 files changed, 17 insertions, 15 deletions
diff --git a/pkg/sentry/socket/netfilter/extensions.go b/pkg/sentry/socket/netfilter/extensions.go
index e0976fed0..e339f9bea 100644
--- a/pkg/sentry/socket/netfilter/extensions.go
+++ b/pkg/sentry/socket/netfilter/extensions.go
@@ -40,13 +40,17 @@ type matchMaker interface {
 	name() string
 
 	// marshal converts from a stack.Matcher to an ABI struct.
-	marshal(matcher stack.Matcher) []byte
+	marshal(matcher matcher) []byte
 
 	// unmarshal converts from the ABI matcher struct to an
 	// stack.Matcher.
 	unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Matcher, error)
 }
 
+type matcher interface {
+	name() string
+}
+
 // matchMakers maps the name of supported matchers to the matchMaker that
 // marshals and unmarshals it. It is immutable after package initialization.
 var matchMakers = map[string]matchMaker{}
@@ -60,8 +64,9 @@ func registerMatchMaker(mm matchMaker) {
 	matchMakers[mm.name()] = mm
 }
 
-func marshalMatcher(matcher stack.Matcher) []byte {
-	matchMaker, ok := matchMakers[matcher.Name()]
+func marshalMatcher(mr stack.Matcher) []byte {
+	matcher := mr.(matcher)
+	matchMaker, ok := matchMakers[matcher.name()]
 	if !ok {
 		panic(fmt.Sprintf("Unknown matcher of type %T.", matcher))
 	}
diff --git a/pkg/sentry/socket/netfilter/owner_matcher.go b/pkg/sentry/socket/netfilter/owner_matcher.go
index 176fa6116..5f80d82ea 100644
--- a/pkg/sentry/socket/netfilter/owner_matcher.go
+++ b/pkg/sentry/socket/netfilter/owner_matcher.go
@@ -38,7 +38,7 @@ func (ownerMarshaler) name() string {
 }
 
 // marshal implements matchMaker.marshal.
-func (ownerMarshaler) marshal(mr stack.Matcher) []byte {
+func (ownerMarshaler) marshal(mr matcher) []byte {
 	matcher := mr.(*OwnerMatcher)
 	iptOwnerInfo := linux.IPTOwnerInfo{
 		UID: matcher.uid,
@@ -106,8 +106,8 @@ type OwnerMatcher struct {
 	invertGID bool
 }
 
-// Name implements Matcher.Name.
-func (*OwnerMatcher) Name() string {
+// name implements matcher.name.
+func (*OwnerMatcher) name() string {
 	return matcherNameOwner
 }
 
diff --git a/pkg/sentry/socket/netfilter/tcp_matcher.go b/pkg/sentry/socket/netfilter/tcp_matcher.go
index 2740697b3..678d6b578 100644
--- a/pkg/sentry/socket/netfilter/tcp_matcher.go
+++ b/pkg/sentry/socket/netfilter/tcp_matcher.go
@@ -39,7 +39,7 @@ func (tcpMarshaler) name() string {
 }
 
 // marshal implements matchMaker.marshal.
-func (tcpMarshaler) marshal(mr stack.Matcher) []byte {
+func (tcpMarshaler) marshal(mr matcher) []byte {
 	matcher := mr.(*TCPMatcher)
 	xttcp := linux.XTTCP{
 		SourcePortStart:      matcher.sourcePortStart,
@@ -90,8 +90,8 @@ type TCPMatcher struct {
 	destinationPortEnd   uint16
 }
 
-// Name implements Matcher.Name.
-func (*TCPMatcher) Name() string {
+// name implements matcher.name.
+func (*TCPMatcher) name() string {
 	return matcherNameTCP
 }
 
diff --git a/pkg/sentry/socket/netfilter/udp_matcher.go b/pkg/sentry/socket/netfilter/udp_matcher.go
index 466d5395d..f8568873f 100644
--- a/pkg/sentry/socket/netfilter/udp_matcher.go
+++ b/pkg/sentry/socket/netfilter/udp_matcher.go
@@ -39,7 +39,7 @@ func (udpMarshaler) name() string {
 }
 
 // marshal implements matchMaker.marshal.
-func (udpMarshaler) marshal(mr stack.Matcher) []byte {
+func (udpMarshaler) marshal(mr matcher) []byte {
 	matcher := mr.(*UDPMatcher)
 	xtudp := linux.XTUDP{
 		SourcePortStart:      matcher.sourcePortStart,
@@ -87,8 +87,8 @@ type UDPMatcher struct {
 	destinationPortEnd   uint16
 }
 
-// Name implements Matcher.Name.
-func (*UDPMatcher) Name() string {
+// name implements Matcher.name.
+func (*UDPMatcher) name() string {
 	return matcherNameUDP
 }
 
diff --git a/pkg/tcpip/stack/iptables_types.go b/pkg/tcpip/stack/iptables_types.go
index fd9d61e39..b0d84befb 100644
--- a/pkg/tcpip/stack/iptables_types.go
+++ b/pkg/tcpip/stack/iptables_types.go
@@ -332,9 +332,6 @@ func filterAddress(addr, mask, filterAddr tcpip.Address, invert bool) bool {
 
 // A Matcher is the interface for matching packets.
 type Matcher interface {
-	// Name returns the name of the Matcher.
-	Name() string
-
 	// Match returns whether the packet matches and whether the packet
 	// should be "hotdropped", i.e. dropped immediately. This is usually
 	// used for suspicious packets.