cmd/devp2p: add discv4 test suite (#21163)

This adds a test suite for discovery v4. The test suite is a port of the Hive suite for
discovery, and will replace the current suite on Hive soon-ish. The tests can be
run locally with this command:

    devp2p discv4 test -remote enode//...

Co-authored-by: Felix Lange <fjl@twurst.com>

cmd/devp2p/discv4cmd.go

@@ -19,11 +19,14 @@ package main
 import (
 	"fmt"
 	"net"
+	"os"
 	"strings"
 	"time"
 
+	"github.com/ethereum/go-ethereum/cmd/devp2p/internal/v4test"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/internal/utesting"
 	"github.com/ethereum/go-ethereum/p2p/discover"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/params"
@@ -40,6 +43,7 @@ var (
 			discv4ResolveCommand,
 			discv4ResolveJSONCommand,
 			discv4CrawlCommand,
+			discv4TestCommand,
 		},
 	}
 	discv4PingCommand = cli.Command{
@@ -74,6 +78,12 @@ var (
 		Action: discv4Crawl,
 		Flags:  []cli.Flag{bootnodesFlag, crawlTimeoutFlag},
 	}
+	discv4TestCommand = cli.Command{
+		Name:   "test",
+		Usage:  "Runs tests against a node",
+		Action: discv4Test,
+		Flags:  []cli.Flag{remoteEnodeFlag, testPatternFlag, testListen1Flag, testListen2Flag},
+	}
 )
 
 var (
@@ -98,6 +108,25 @@ var (
 		Usage: "Time limit for the crawl.",
 		Value: 30 * time.Minute,
 	}
+	remoteEnodeFlag = cli.StringFlag{
+		Name:   "remote",
+		Usage:  "Enode of the remote node under test",
+		EnvVar: "REMOTE_ENODE",
+	}
+	testPatternFlag = cli.StringFlag{
+		Name:  "run",
+		Usage: "Pattern of test suite(s) to run",
+	}
+	testListen1Flag = cli.StringFlag{
+		Name:  "listen1",
+		Usage: "IP address of the first tester",
+		Value: v4test.Listen1,
+	}
+	testListen2Flag = cli.StringFlag{
+		Name:  "listen2",
+		Usage: "IP address of the second tester",
+		Value: v4test.Listen2,
+	}
 )
 
 func discv4Ping(ctx *cli.Context) error {
@@ -184,6 +213,28 @@ func discv4Crawl(ctx *cli.Context) error {
 	return nil
 }
 
+func discv4Test(ctx *cli.Context) error {
+	// Configure test package globals.
+	if !ctx.IsSet(remoteEnodeFlag.Name) {
+		return fmt.Errorf("Missing -%v", remoteEnodeFlag.Name)
+	}
+	v4test.Remote = ctx.String(remoteEnodeFlag.Name)
+	v4test.Listen1 = ctx.String(testListen1Flag.Name)
+	v4test.Listen2 = ctx.String(testListen2Flag.Name)
+
+	// Filter and run test cases.
+	tests := v4test.AllTests
+	if ctx.IsSet(testPatternFlag.Name) {
+		tests = utesting.MatchTests(tests, ctx.String(testPatternFlag.Name))
+	}
+	results := utesting.RunTests(tests, os.Stdout)
+	if fails := utesting.CountFailures(results); fails > 0 {
+		return fmt.Errorf("%v/%v tests passed.", len(tests)-fails, len(tests))
+	}
+	fmt.Printf("%v/%v passed\n", len(tests), len(tests))
+	return nil
+}
+
 // startV4 starts an ephemeral discovery V4 node.
 func startV4(ctx *cli.Context) *discover.UDPv4 {
 	ln, config := makeDiscoveryConfig(ctx)