Move multicounter testutil functions out of network/ip

This is in preparation of having aggregated NIC stats at the stack
level. These validation functions will be needed outside of the
network layer packages to test aggregated NIC stats.

PiperOrigin-RevId: 373180565

9 files changed, 16 insertions, 111 deletions

diff --git a/pkg/tcpip/network/arp/BUILD b/pkg/tcpip/network/arp/BUILD
index 6905b9ccb..a72eb1aad 100644
--- a/pkg/tcpip/network/arp/BUILD
+++ b/pkg/tcpip/network/arp/BUILD
@@ -47,7 +47,7 @@ go_test(
     library = ":arp",
     deps = [
         "//pkg/tcpip",
-        "//pkg/tcpip/network/internal/testutil",
         "//pkg/tcpip/stack",
+        "//pkg/tcpip/testutil",
     ],
 )
diff --git a/pkg/tcpip/network/arp/stats_test.go b/pkg/tcpip/network/arp/stats_test.go
index e867b3c3f..0df39ae81 100644
--- a/pkg/tcpip/network/arp/stats_test.go
+++ b/pkg/tcpip/network/arp/stats_test.go
@@ -19,8 +19,8 @@ import (
 	"testing"
 
 	"gvisor.dev/gvisor/pkg/tcpip"
-	"gvisor.dev/gvisor/pkg/tcpip/network/internal/testutil"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
+	"gvisor.dev/gvisor/pkg/tcpip/testutil"
 )
 
 var _ stack.NetworkInterface = (*testInterface)(nil)
diff --git a/pkg/tcpip/network/internal/testutil/BUILD b/pkg/tcpip/network/internal/testutil/BUILD
index 1c4f583c7..cec3e62c4 100644
--- a/pkg/tcpip/network/internal/testutil/BUILD
+++ b/pkg/tcpip/network/internal/testutil/BUILD
@@ -4,10 +4,7 @@ package(licenses = ["notice"])
 
 go_library(
     name = "testutil",
-    srcs = [
-        "testutil.go",
-        "testutil_unsafe.go",
-    ],
+    srcs = ["testutil.go"],
     visibility = [
         "//pkg/tcpip/network/arp:__pkg__",
         "//pkg/tcpip/network/internal/fragmentation:__pkg__",
diff --git a/pkg/tcpip/network/internal/testutil/testutil.go b/pkg/tcpip/network/internal/testutil/testutil.go
index e2cf24b67..605e9ef8d 100644
--- a/pkg/tcpip/network/internal/testutil/testutil.go
+++ b/pkg/tcpip/network/internal/testutil/testutil.go
@@ -19,8 +19,6 @@ package testutil
 import (
 	"fmt"
 	"math/rand"
-	"reflect"
-	"strings"
 
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/buffer"
@@ -129,69 +127,3 @@ func MakeRandPkt(transportHeaderLength int, extraHeaderReserveLength int, viewSi
 	}
 	return pkt
 }
-
-func checkFieldCounts(ref, multi reflect.Value) error {
-	refTypeName := ref.Type().Name()
-	multiTypeName := multi.Type().Name()
-	refNumField := ref.NumField()
-	multiNumField := multi.NumField()
-
-	if refNumField != multiNumField {
-		return fmt.Errorf("type %s has an incorrect number of fields: got = %d, want = %d (same as type %s)", multiTypeName, multiNumField, refNumField, refTypeName)
-	}
-
-	return nil
-}
-
-func validateField(ref reflect.Value, refName string, m tcpip.MultiCounterStat, multiName string) error {
-	s, ok := ref.Addr().Interface().(**tcpip.StatCounter)
-	if !ok {
-		return fmt.Errorf("expected ref type's to be *StatCounter, but its type is %s", ref.Type().Elem().Name())
-	}
-
-	// The field names are expected to match (case insensitive).
-	if !strings.EqualFold(refName, multiName) {
-		return fmt.Errorf("wrong field name: got = %s, want = %s", multiName, refName)
-	}
-
-	base := (*s).Value()
-	m.Increment()
-	if (*s).Value() != base+1 {
-		return fmt.Errorf("updates to the '%s MultiCounterStat' counters are not reflected in the '%s CounterStat'", multiName, refName)
-	}
-
-	return nil
-}
-
-// ValidateMultiCounterStats verifies that every counter stored in multi is
-// correctly tracking its counterpart in the given counters.
-func ValidateMultiCounterStats(multi reflect.Value, counters []reflect.Value) error {
-	for _, c := range counters {
-		if err := checkFieldCounts(c, multi); err != nil {
-			return err
-		}
-	}
-
-	for i := 0; i < multi.NumField(); i++ {
-		multiName := multi.Type().Field(i).Name
-		multiUnsafe := unsafeExposeUnexportedFields(multi.Field(i))
-
-		if m, ok := multiUnsafe.Addr().Interface().(*tcpip.MultiCounterStat); ok {
-			for _, c := range counters {
-				if err := validateField(unsafeExposeUnexportedFields(c.Field(i)), c.Type().Field(i).Name, *m, multiName); err != nil {
-					return err
-				}
-			}
-		} else {
-			var countersNextField []reflect.Value
-			for _, c := range counters {
-				countersNextField = append(countersNextField, c.Field(i))
-			}
-			if err := ValidateMultiCounterStats(multi.Field(i), countersNextField); err != nil {
-				return err
-			}
-		}
-	}
-
-	return nil
-}
diff --git a/pkg/tcpip/network/internal/testutil/testutil_unsafe.go b/pkg/tcpip/network/internal/testutil/testutil_unsafe.go
deleted file mode 100644
index 5ff764800..000000000
--- a/pkg/tcpip/network/internal/testutil/testutil_unsafe.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Copyright 2020 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package testutil
-
-import (
-	"reflect"
-	"unsafe"
-)
-
-// unsafeExposeUnexportedFields takes a Value and returns a version of it in
-// which even unexported fields can be read and written.
-func unsafeExposeUnexportedFields(a reflect.Value) reflect.Value {
-	return reflect.NewAt(a.Type(), unsafe.Pointer(a.UnsafeAddr())).Elem()
-}
diff --git a/pkg/tcpip/network/ipv4/BUILD b/pkg/tcpip/network/ipv4/BUILD
index 7ee0495d9..c90974693 100644
--- a/pkg/tcpip/network/ipv4/BUILD
+++ b/pkg/tcpip/network/ipv4/BUILD
@@ -62,7 +62,7 @@ go_test(
     library = ":ipv4",
     deps = [
         "//pkg/tcpip",
-        "//pkg/tcpip/network/internal/testutil",
         "//pkg/tcpip/stack",
+        "//pkg/tcpip/testutil",
     ],
 )
diff --git a/pkg/tcpip/network/ipv4/stats_test.go b/pkg/tcpip/network/ipv4/stats_test.go
index a637f9d50..d1f9e3cf5 100644
--- a/pkg/tcpip/network/ipv4/stats_test.go
+++ b/pkg/tcpip/network/ipv4/stats_test.go
@@ -19,8 +19,8 @@ import (
 	"testing"
 
 	"gvisor.dev/gvisor/pkg/tcpip"
-	"gvisor.dev/gvisor/pkg/tcpip/network/internal/testutil"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
+	"gvisor.dev/gvisor/pkg/tcpip/testutil"
 )
 
 var _ stack.NetworkInterface = (*testInterface)(nil)
diff --git a/pkg/tcpip/network/ipv6/BUILD b/pkg/tcpip/network/ipv6/BUILD
index db998e83e..f99cbf8f3 100644
--- a/pkg/tcpip/network/ipv6/BUILD
+++ b/pkg/tcpip/network/ipv6/BUILD
@@ -45,6 +45,7 @@ go_test(
         "//pkg/tcpip/link/sniffer",
         "//pkg/tcpip/network/internal/testutil",
         "//pkg/tcpip/stack",
+        "//pkg/tcpip/testutil",
         "//pkg/tcpip/transport/icmp",
         "//pkg/tcpip/transport/tcp",
         "//pkg/tcpip/transport/udp",
diff --git a/pkg/tcpip/network/ipv6/ipv6_test.go b/pkg/tcpip/network/ipv6/ipv6_test.go
index 5307516d7..8ebca735b 100644
--- a/pkg/tcpip/network/ipv6/ipv6_test.go
+++ b/pkg/tcpip/network/ipv6/ipv6_test.go
@@ -31,8 +31,9 @@ import (
 	"gvisor.dev/gvisor/pkg/tcpip/faketime"
 	"gvisor.dev/gvisor/pkg/tcpip/header"
 	"gvisor.dev/gvisor/pkg/tcpip/link/channel"
-	"gvisor.dev/gvisor/pkg/tcpip/network/internal/testutil"
+	iptestutil "gvisor.dev/gvisor/pkg/tcpip/network/internal/testutil"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
+	"gvisor.dev/gvisor/pkg/tcpip/testutil"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
@@ -2603,7 +2604,7 @@ func TestWriteStats(t *testing.T) {
 		t.Run(writer.name, func(t *testing.T) {
 			for _, test := range tests {
 				t.Run(test.name, func(t *testing.T) {
-					ep := testutil.NewMockLinkEndpoint(header.IPv6MinimumMTU, &tcpip.ErrInvalidEndpointState{}, test.allowPackets)
+					ep := iptestutil.NewMockLinkEndpoint(header.IPv6MinimumMTU, &tcpip.ErrInvalidEndpointState{}, test.allowPackets)
 					rt := buildRoute(t, ep)
 					var pkts stack.PacketBufferList
 					for i := 0; i < nPackets; i++ {
@@ -2802,9 +2803,9 @@ func TestFragmentationWritePacket(t *testing.T) {
 
 	for _, ft := range fragmentationTests {
 		t.Run(ft.description, func(t *testing.T) {
-			pkt := testutil.MakeRandPkt(ft.transHdrLen, extraHeaderReserve+header.IPv6MinimumSize, []int{ft.payloadSize}, header.IPv6ProtocolNumber)
+			pkt := iptestutil.MakeRandPkt(ft.transHdrLen, extraHeaderReserve+header.IPv6MinimumSize, []int{ft.payloadSize}, header.IPv6ProtocolNumber)
 			source := pkt.Clone()
-			ep := testutil.NewMockLinkEndpoint(ft.mtu, nil, math.MaxInt32)
+			ep := iptestutil.NewMockLinkEndpoint(ft.mtu, nil, math.MaxInt32)
 			r := buildRoute(t, ep)
 			err := r.WritePacket(stack.NetworkHeaderParams{
 				Protocol: tcp.ProtocolNumber,
@@ -2858,7 +2859,7 @@ func TestFragmentationWritePackets(t *testing.T) {
 			insertAfter:  1,
 		},
 	}
-	tinyPacket := testutil.MakeRandPkt(header.TCPMinimumSize, extraHeaderReserve+header.IPv6MinimumSize, []int{1}, header.IPv6ProtocolNumber)
+	tinyPacket := iptestutil.MakeRandPkt(header.TCPMinimumSize, extraHeaderReserve+header.IPv6MinimumSize, []int{1}, header.IPv6ProtocolNumber)
 
 	for _, test := range tests {
 		t.Run(test.description, func(t *testing.T) {
@@ -2868,14 +2869,14 @@ func TestFragmentationWritePackets(t *testing.T) {
 					for i := 0; i < test.insertBefore; i++ {
 						pkts.PushBack(tinyPacket.Clone())
 					}
-					pkt := testutil.MakeRandPkt(ft.transHdrLen, extraHeaderReserve+header.IPv6MinimumSize, []int{ft.payloadSize}, header.IPv6ProtocolNumber)
+					pkt := iptestutil.MakeRandPkt(ft.transHdrLen, extraHeaderReserve+header.IPv6MinimumSize, []int{ft.payloadSize}, header.IPv6ProtocolNumber)
 					source := pkt
 					pkts.PushBack(pkt.Clone())
 					for i := 0; i < test.insertAfter; i++ {
 						pkts.PushBack(tinyPacket.Clone())
 					}
 
-					ep := testutil.NewMockLinkEndpoint(ft.mtu, nil, math.MaxInt32)
+					ep := iptestutil.NewMockLinkEndpoint(ft.mtu, nil, math.MaxInt32)
 					r := buildRoute(t, ep)
 
 					wantTotalPackets := len(ft.wantFragments) + test.insertBefore + test.insertAfter
@@ -2980,8 +2981,8 @@ func TestFragmentationErrors(t *testing.T) {
 
 	for _, ft := range tests {
 		t.Run(ft.description, func(t *testing.T) {
-			pkt := testutil.MakeRandPkt(ft.transHdrLen, extraHeaderReserve+header.IPv6MinimumSize, []int{ft.payloadSize}, header.IPv6ProtocolNumber)
-			ep := testutil.NewMockLinkEndpoint(ft.mtu, ft.mockError, ft.allowPackets)
+			pkt := iptestutil.MakeRandPkt(ft.transHdrLen, extraHeaderReserve+header.IPv6MinimumSize, []int{ft.payloadSize}, header.IPv6ProtocolNumber)
+			ep := iptestutil.NewMockLinkEndpoint(ft.mtu, ft.mockError, ft.allowPackets)
 			r := buildRoute(t, ep)
 			err := r.WritePacket(stack.NetworkHeaderParams{
 				Protocol: tcp.ProtocolNumber,