Fix simple mistakes identified by goreportcard.

These are primarily simplification and lint mistakes. However, minor
fixes are also included and tests added where appropriate.

PiperOrigin-RevId: 351425971

3 files changed, 44 insertions, 46 deletions

diff --git a/pkg/tcpip/stack/conntrack.go b/pkg/tcpip/stack/conntrack.go
index 9a17efcba..5e649cca6 100644
--- a/pkg/tcpip/stack/conntrack.go
+++ b/pkg/tcpip/stack/conntrack.go
@@ -142,19 +142,19 @@ func (cn *conn) timedOut(now time.Time) bool {
 
 // update the connection tracking state.
 //
-// Precondition: ct.mu must be held.
-func (ct *conn) updateLocked(tcpHeader header.TCP, hook Hook) {
+// Precondition: cn.mu must be held.
+func (cn *conn) updateLocked(tcpHeader header.TCP, hook Hook) {
 	// Update the state of tcb. tcb assumes it's always initialized on the
 	// client. However, we only need to know whether the connection is
 	// established or not, so the client/server distinction isn't important.
 	// TODO(gvisor.dev/issue/170): Add support in tcpconntrack to handle
 	// other tcp states.
-	if ct.tcb.IsEmpty() {
-		ct.tcb.Init(tcpHeader)
-	} else if hook == ct.tcbHook {
-		ct.tcb.UpdateStateOutbound(tcpHeader)
+	if cn.tcb.IsEmpty() {
+		cn.tcb.Init(tcpHeader)
+	} else if hook == cn.tcbHook {
+		cn.tcb.UpdateStateOutbound(tcpHeader)
 	} else {
-		ct.tcb.UpdateStateInbound(tcpHeader)
+		cn.tcb.UpdateStateInbound(tcpHeader)
 	}
 }
 
diff --git a/pkg/tcpip/stack/iptables.go b/pkg/tcpip/stack/iptables.go
index 2d8c883cd..09c7811fa 100644
--- a/pkg/tcpip/stack/iptables.go
+++ b/pkg/tcpip/stack/iptables.go
@@ -45,13 +45,13 @@ const reaperDelay = 5 * time.Second
 func DefaultTables() *IPTables {
 	return &IPTables{
 		v4Tables: [NumTables]Table{
-			NATID: Table{
+			NATID: {
 				Rules: []Rule{
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
-					Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &ErrorTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
 				},
 				BuiltinChains: [NumHooks]int{
 					Prerouting:  0,
@@ -68,11 +68,11 @@ func DefaultTables() *IPTables {
 					Postrouting: 3,
 				},
 			},
-			MangleID: Table{
+			MangleID: {
 				Rules: []Rule{
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
-					Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &ErrorTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
 				},
 				BuiltinChains: [NumHooks]int{
 					Prerouting: 0,
@@ -86,12 +86,12 @@ func DefaultTables() *IPTables {
 					Postrouting: HookUnset,
 				},
 			},
-			FilterID: Table{
+			FilterID: {
 				Rules: []Rule{
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
-					Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
+					{Target: &ErrorTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
 				},
 				BuiltinChains: [NumHooks]int{
 					Prerouting:  HookUnset,
@@ -110,13 +110,13 @@ func DefaultTables() *IPTables {
 			},
 		},
 		v6Tables: [NumTables]Table{
-			NATID: Table{
+			NATID: {
 				Rules: []Rule{
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
-					Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &ErrorTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
 				},
 				BuiltinChains: [NumHooks]int{
 					Prerouting:  0,
@@ -133,11 +133,11 @@ func DefaultTables() *IPTables {
 					Postrouting: 3,
 				},
 			},
-			MangleID: Table{
+			MangleID: {
 				Rules: []Rule{
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
-					Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &ErrorTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
 				},
 				BuiltinChains: [NumHooks]int{
 					Prerouting: 0,
@@ -151,12 +151,12 @@ func DefaultTables() *IPTables {
 					Postrouting: HookUnset,
 				},
 			},
-			FilterID: Table{
+			FilterID: {
 				Rules: []Rule{
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
-					Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
-					Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
+					{Target: &ErrorTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
 				},
 				BuiltinChains: [NumHooks]int{
 					Prerouting:  HookUnset,
@@ -175,9 +175,9 @@ func DefaultTables() *IPTables {
 			},
 		},
 		priorities: [NumHooks][]TableID{
-			Prerouting: []TableID{MangleID, NATID},
-			Input:      []TableID{NATID, FilterID},
-			Output:     []TableID{MangleID, NATID, FilterID},
+			Prerouting: {MangleID, NATID},
+			Input:      {NATID, FilterID},
+			Output:     {MangleID, NATID, FilterID},
 		},
 		connections: ConnTrack{
 			seed: generateRandUint32(),
diff --git a/pkg/tcpip/stack/iptables_types.go b/pkg/tcpip/stack/iptables_types.go
index 4b86c1be9..56a3e7861 100644
--- a/pkg/tcpip/stack/iptables_types.go
+++ b/pkg/tcpip/stack/iptables_types.go
@@ -56,7 +56,7 @@ const (
 	// Postrouting happens just before a packet goes out on the wire.
 	Postrouting
 
-	// The total number of hooks.
+	// NumHooks is the total number of hooks.
 	NumHooks
 )
 
@@ -273,14 +273,12 @@ func (fl IPHeaderFilter) match(pkt *PacketBuffer, hook Hook, nicName string) boo
 			return true
 		}
 
-		// If the interface name ends with '+', any interface which begins
-		// with the name should be matched.
+		// If the interface name ends with '+', any interface which
+		// begins with the name should be matched.
 		ifName := fl.OutputInterface
-		matches := true
+		matches := nicName == ifName
 		if strings.HasSuffix(ifName, "+") {
 			matches = strings.HasPrefix(nicName, ifName[:n-1])
-		} else {
-			matches = nicName == ifName
 		}
 		return fl.OutputInterfaceInvert != matches
 	}