op-node: protocol versions signal handling

go.mod

@@ -208,6 +208,6 @@ require (
 	rsc.io/tmplfunc v0.0.3 // indirect
 )
 
-replace github.com/ethereum/go-ethereum v1.12.0 => github.com/ethereum-optimism/op-geth v1.101200.0-rc.1.0.20230818191139-f7376a28049b
+replace github.com/ethereum/go-ethereum v1.12.0 => github.com/ethereum-optimism/op-geth v1.101200.2-rc.1.0.20230913104329-60b827bfc2de
 
 //replace github.com/ethereum/go-ethereum v1.12.0 => ../go-ethereum

go.sum

@@ -162,8 +162,8 @@ github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7
 github.com/etcd-io/bbolt v1.3.3/go.mod h1:ZF2nL25h33cCyBtcyWeZ2/I3HQOfTP+0PIEvHjkjCrw=
 github.com/ethereum-optimism/go-ethereum-hdwallet v0.1.3 h1:RWHKLhCrQThMfch+QJ1Z8veEq5ZO3DfIhZ7xgRP9WTc=
 github.com/ethereum-optimism/go-ethereum-hdwallet v0.1.3/go.mod h1:QziizLAiF0KqyLdNJYD7O5cpDlaFMNZzlxYNcWsJUxs=
-github.com/ethereum-optimism/op-geth v1.101200.0-rc.1.0.20230818191139-f7376a28049b h1:YF2FE/QnbhvrHwDYJHnbTKgJvw2aKwB/dd7PO1zKNqY=
-github.com/ethereum-optimism/op-geth v1.101200.0-rc.1.0.20230818191139-f7376a28049b/go.mod h1:gRnPb21PoKcHm3kHqj9BQlQkwmhOGUvQoGEbC7z852Q=
+github.com/ethereum-optimism/op-geth v1.101200.2-rc.1.0.20230913104329-60b827bfc2de h1:nxgmsH13qzkWlX5dXrVzsTHqtu/XHfAWkyfpH+9ljqw=
+github.com/ethereum-optimism/op-geth v1.101200.2-rc.1.0.20230913104329-60b827bfc2de/go.mod h1:gRnPb21PoKcHm3kHqj9BQlQkwmhOGUvQoGEbC7z852Q=
 github.com/ethereum-optimism/superchain-registry/superchain v0.0.0-20230817174831-5d3ca1966435 h1:2CzkJkkTLuVyoVFkoW5w6vDB2Q7eJzxXw/ybA17xjqM=
 github.com/ethereum-optimism/superchain-registry/superchain v0.0.0-20230817174831-5d3ca1966435/go.mod h1:v2YpePbdGBF0Gr6VWq49MFFmcTW0kRYZ2ingBJYWEwg=
 github.com/ethereum/c-kzg-4844 v0.2.0 h1:+cUvymlnoDDQgMInp25Bo3OmLajmmY8mLJ/tLjqd77Q=

op-chain-ops/genesis/config.go

@@ -15,6 +15,7 @@ import (
 	gstate "github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rpc"
 
 	"github.com/ethereum-optimism/optimism/op-bindings/hardhat"
@@ -199,10 +200,10 @@ type DeployConfig struct {
 	FundDevAccounts bool `json:"fundDevAccounts"`
 	// RequiredProtocolVersion indicates the protocol version that
 	// nodes are required to adopt, to stay in sync with the network.
-	RequiredProtocolVersion common.Hash `json:"requiredProtocolVersion"`
+	RequiredProtocolVersion params.ProtocolVersion `json:"requiredProtocolVersion"`
 	// RequiredProtocolVersion indicates the protocol version that
 	// nodes are recommended to adopt, to stay in sync with the network.
-	RecommendedProtocolVersion common.Hash `json:"recommendedProtocolVersion"`
+	RecommendedProtocolVersion params.ProtocolVersion `json:"recommendedProtocolVersion"`
 }
 
 // Copy will deeply copy the DeployConfig. This does a JSON roundtrip to copy

op-e2e/setup.go

@@ -408,16 +408,17 @@ func (cfg SystemConfig) Start(t *testing.T, _opts ...SystemConfigOption) (*Syste
 				L2Time:       uint64(cfg.DeployConfig.L1GenesisBlockTimestamp),
 				SystemConfig: e2eutils.SystemConfigFromDeployConfig(cfg.DeployConfig),
 			},
-			BlockTime:              cfg.DeployConfig.L2BlockTime,
-			MaxSequencerDrift:      cfg.DeployConfig.MaxSequencerDrift,
-			SeqWindowSize:          cfg.DeployConfig.SequencerWindowSize,
-			ChannelTimeout:         cfg.DeployConfig.ChannelTimeout,
-			L1ChainID:              cfg.L1ChainIDBig(),
-			L2ChainID:              cfg.L2ChainIDBig(),
-			BatchInboxAddress:      cfg.DeployConfig.BatchInboxAddress,
-			DepositContractAddress: cfg.DeployConfig.OptimismPortalProxy,
-			L1SystemConfigAddress:  cfg.DeployConfig.SystemConfigProxy,
-			RegolithTime:           cfg.DeployConfig.RegolithTime(uint64(cfg.DeployConfig.L1GenesisBlockTimestamp)),
+			BlockTime:               cfg.DeployConfig.L2BlockTime,
+			MaxSequencerDrift:       cfg.DeployConfig.MaxSequencerDrift,
+			SeqWindowSize:           cfg.DeployConfig.SequencerWindowSize,
+			ChannelTimeout:          cfg.DeployConfig.ChannelTimeout,
+			L1ChainID:               cfg.L1ChainIDBig(),
+			L2ChainID:               cfg.L2ChainIDBig(),
+			BatchInboxAddress:       cfg.DeployConfig.BatchInboxAddress,
+			DepositContractAddress:  cfg.DeployConfig.OptimismPortalProxy,
+			L1SystemConfigAddress:   cfg.DeployConfig.SystemConfigProxy,
+			RegolithTime:            cfg.DeployConfig.RegolithTime(uint64(cfg.DeployConfig.L1GenesisBlockTimestamp)),
+			ProtocolVersionsAddress: cfg.L1Deployments.ProtocolVersionsProxy,
 		}
 	}
 	defaultConfig := makeRollupConfig()

op-e2e/system_test.go

@@ -2,6 +2,7 @@ package op_e2e
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"math/big"
 	"os"
@@ -1434,3 +1435,120 @@ func TestRuntimeConfigReload(t *testing.T) {
 	})
 	require.NoError(t, err)
 }
+
+func TestRecommendedProtocolVersionChange(t *testing.T) {
+	InitParallel(t)
+
+	cfg := DefaultSystemConfig(t)
+	require.NotEqual(t, common.Address{}, cfg.L1Deployments.ProtocolVersions, "need ProtocolVersions contract deployment")
+	// to speed up the test, make it reload the config more often, and do not impose a long conf depth
+	cfg.Nodes["verifier"].RuntimeConfigReloadInterval = time.Second * 5
+	cfg.Nodes["verifier"].Driver.VerifierConfDepth = 1
+
+	sys, err := cfg.Start(t)
+	require.Nil(t, err, "Error starting up system")
+	defer sys.Close()
+	runtimeConfig := sys.RollupNodes["verifier"].RuntimeConfig()
+
+	// Change the superchain-config via L1
+	l1 := sys.Clients["l1"]
+
+	_, build, major, minor, patch, preRelease := params.OPStackSupport.Parse()
+	newRecommendedProtocolVersion := params.ToProtocolVersion(build, major+1, minor, patch, preRelease)
+	require.NotEqual(t, runtimeConfig.RecommendedProtocolVersion(), newRecommendedProtocolVersion, "changing to a different protocol version")
+
+	protVersions, err := bindings.NewProtocolVersions(cfg.L1Deployments.ProtocolVersionsProxy, l1)
+	require.NoError(t, err)
+
+	// ProtocolVersions contract is owned by same key as SystemConfig in devnet
+	opts, err := bind.NewKeyedTransactorWithChainID(cfg.Secrets.SysCfgOwner, cfg.L1ChainIDBig())
+	require.NoError(t, err)
+
+	// Change recommended protocol version
+	tx, err := protVersions.SetRecommended(opts, new(big.Int).SetBytes(newRecommendedProtocolVersion[:]))
+	require.NoError(t, err)
+
+	// wait for the change to confirm
+	_, err = wait.ForReceiptOK(context.Background(), l1, tx.Hash())
+	require.NoError(t, err)
+
+	// wait for the recommended protocol version to change
+	_, err = retry.Do(context.Background(), 10, retry.Fixed(time.Second*10), func() (struct{}, error) {
+		v := sys.RollupNodes["verifier"].RuntimeConfig().RecommendedProtocolVersion()
+		if v == newRecommendedProtocolVersion {
+			return struct{}{}, nil
+		}
+		return struct{}{}, fmt.Errorf("no change yet, seeing %s but looking for %s", v, newRecommendedProtocolVersion)
+	})
+	require.NoError(t, err)
+}
+
+func TestRequiredProtocolVersionChangeAndHalt(t *testing.T) {
+	InitParallel(t)
+
+	cfg := DefaultSystemConfig(t)
+	// activate the functionality by updating the config // TODO may need to just activate it by default in op-e2e?
+	cfg.Nodes["verifier"].Rollup.ProtocolVersionsAddress = cfg.L1Deployments.ProtocolVersions
+	// to speed up the test, make it reload the config more often, and do not impose a long conf depth
+	cfg.Nodes["verifier"].RuntimeConfigReloadInterval = time.Second * 5
+	cfg.Nodes["verifier"].Driver.VerifierConfDepth = 1
+	// configure halt in verifier op-node
+	cfg.Nodes["verifier"].RollupHalt = "major"
+	// configure halt in verifier op-geth node
+	cfg.GethOptions["verifier"] = []geth.GethOption{
+		func(ethCfg *ethconfig.Config, nodeCfg *node.Config) error {
+			ethCfg.RollupHaltOnIncompatibleProtocolVersion = "major"
+			return nil
+		},
+	}
+
+	sys, err := cfg.Start(t)
+	require.Nil(t, err, "Error starting up system")
+	defer sys.Close()
+	runtimeConfig := sys.RollupNodes["verifier"].RuntimeConfig()
+
+	// Change the superchain-config via L1
+	l1 := sys.Clients["l1"]
+
+	_, build, major, minor, patch, preRelease := params.OPStackSupport.Parse()
+	newRequiredProtocolVersion := params.ToProtocolVersion(build, major+1, minor, patch, preRelease)
+	require.NotEqual(t, runtimeConfig.RequiredProtocolVersion(), newRequiredProtocolVersion, "changing to a different protocol version")
+
+	protVersions, err := bindings.NewProtocolVersions(cfg.L1Deployments.ProtocolVersionsProxy, l1)
+	require.NoError(t, err)
+
+	// ProtocolVersions contract is owned by same key as SystemConfig in devnet
+	opts, err := bind.NewKeyedTransactorWithChainID(cfg.Secrets.SysCfgOwner, cfg.L1ChainIDBig())
+	require.NoError(t, err)
+
+	// Change required protocol version
+	tx, err := protVersions.SetRequired(opts, new(big.Int).SetBytes(newRequiredProtocolVersion[:]))
+	require.NoError(t, err)
+
+	// wait for the change to confirm
+	_, err = wait.ForReceiptOK(context.Background(), l1, tx.Hash())
+	require.NoError(t, err)
+
+	// wait for the required protocol version to take effect by halting the verifier that opted in, and halting the op-geth node that opted in.
+	_, err = retry.Do(context.Background(), 10, retry.Fixed(time.Second*10), func() (struct{}, error) {
+		if !sys.RollupNodes["verifier"].Closed() {
+			return struct{}{}, errors.New("verifier rollup node is not closed yet")
+		}
+		return struct{}{}, nil
+	})
+	require.NoError(t, err)
+	t.Log("verified that op-node closed!")
+	// Checking if the engine is down is not trivial in op-e2e.
+	// In op-geth we have halting tests covering the Engine API, in op-e2e we instead check if the API stops.
+	_, err = retry.Do(context.Background(), 10, retry.Fixed(time.Second*10), func() (struct{}, error) {
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
+		_, err := sys.Clients["verifier"].ChainID(ctx)
+		cancel()
+		if err != nil && !errors.Is(err, ctx.Err()) { // waiting for client to stop responding to chainID requests
+			return struct{}{}, nil
+		}
+		return struct{}{}, errors.New("verifier rollup node is not closed yet")
+	})
+	require.NoError(t, err)
+	t.Log("verified that op-geth closed!")
+}

op-node/flags/flags.go

@@ -244,6 +244,18 @@ var (
 		EnvVars: prefixEnvVars("BETA_EXTRA_NETWORKS"),
 		Hidden:  true,
 	}
+	BetaRollupHalt = &cli.StringFlag{
+		Name:    "beta.rollup.halt",
+		Usage:   "Beta feature: opt-in option to halt on incompatible protocol version requirements of the given level (major/minor/patch/none), as signaled onchain in L1",
+		EnvVars: prefixEnvVars("BETA_ROLLUP_HALT"),
+		Hidden:  true,
+	}
+	BetaRollupLoadProtocolVersions = &cli.BoolFlag{
+		Name:    "beta.rollup.load-protocol-versions",
+		Usage:   "Beta feature: load protocol versions from the superchain L1 ProtocolVersions contract (if available), and report in logs and metrics",
+		EnvVars: prefixEnvVars("BETA_ROLLUP_LOAD_PROTOCOL_VERSIONS"),
+		Hidden:  true,
+	}
 )
 
 var requiredFlags = []cli.Flag{
@@ -286,6 +298,8 @@ var optionalFlags = []cli.Flag{
 	L2EngineSyncEnabled,
 	SkipSyncStartCheck,
 	BetaExtraNetworks,
+	BetaRollupHalt,
+	BetaRollupLoadProtocolVersions,
 }
 
 // Flags contains the list of configuration options available to the binary.

op-node/metrics/metrics.go

@@ -10,6 +10,8 @@ import (
 	"strconv"
 	"time"
 
+	"github.com/ethereum/go-ethereum/params"
+
 	"github.com/ethereum-optimism/optimism/op-node/p2p/store"
 	ophttp "github.com/ethereum-optimism/optimism/op-service/httputil"
 	"github.com/ethereum-optimism/optimism/op-service/metrics"
@@ -78,6 +80,7 @@ type Metricer interface {
 	RecordIPUnban()
 	RecordDial(allow bool)
 	RecordAccept(allow bool)
+	ReportProtocolVersions(local, engine, recommended, required params.ProtocolVersion)
 }
 
 // Metrics tracks all the metrics for the op-node.
@@ -153,6 +156,12 @@ type Metrics struct {
 
 	ChannelInputBytes prometheus.Counter
 
+	// Protocol version reporting
+	// Delta = params.ProtocolVersionComparison
+	ProtocolVersionDelta *prometheus.GaugeVec
+	// ProtocolVersions is pseudo-metric to report the exact protocol version info
+	ProtocolVersions *prometheus.GaugeVec
+
 	registry *prometheus.Registry
 	factory  metrics.Factory
 }
@@ -452,6 +461,24 @@ func NewMetrics(procName string) *Metrics {
 			Help:      "Number of sequencer block sealing jobs",
 		}),
 
+		ProtocolVersionDelta: factory.NewGaugeVec(prometheus.GaugeOpts{
+			Namespace: ns,
+			Name:      "protocol_version_delta",
+			Help:      "Difference between local and global protocol version, and execution-engine, per type of version",
+		}, []string{
+			"type",
+		}),
+		ProtocolVersions: factory.NewGaugeVec(prometheus.GaugeOpts{
+			Namespace: ns,
+			Name:      "protocol_versions",
+			Help:      "Pseudo-metric tracking recommended and required protocol version info",
+		}, []string{
+			"local",
+			"engine",
+			"recommended",
+			"required",
+		}),
+
 		registry: registry,
 		factory:  factory,
 	}
@@ -747,6 +774,13 @@ func (m *Metrics) RecordAccept(allow bool) {
 		m.Accepts.WithLabelValues("false").Inc()
 	}
 }
+func (m *Metrics) ReportProtocolVersions(local, engine, recommended, required params.ProtocolVersion) {
+	m.ProtocolVersionDelta.WithLabelValues("local_recommended").Set(float64(local.Compare(recommended)))
+	m.ProtocolVersionDelta.WithLabelValues("local_required").Set(float64(local.Compare(required)))
+	m.ProtocolVersionDelta.WithLabelValues("engine_recommended").Set(float64(engine.Compare(recommended)))
+	m.ProtocolVersionDelta.WithLabelValues("engine_required").Set(float64(engine.Compare(required)))
+	m.ProtocolVersions.WithLabelValues(local.String(), engine.String(), recommended.String(), required.String()).Set(1)
+}
 
 type noopMetricer struct{}
 
@@ -874,3 +908,5 @@ func (n *noopMetricer) RecordDial(allow bool) {
 
 func (n *noopMetricer) RecordAccept(allow bool) {
 }
+func (n *noopMetricer) ReportProtocolVersions(local, engine, recommended, required params.ProtocolVersion) {
+}

op-node/node/config.go

@@ -42,7 +42,7 @@ type Config struct {
 	ConfigPersistence ConfigPersistence
 
 	// RuntimeConfigReloadInterval defines the interval between runtime config reloads.
-	// Disabled if 0.
+	// Disabled if <= 0.
 	// Runtime config changes should be picked up from log-events,
 	// but if log-events are not coming in (e.g. not syncing blocks) then the reload ensures the config stays accurate.
 	RuntimeConfigReloadInterval time.Duration
@@ -52,6 +52,10 @@ type Config struct {
 	Heartbeat HeartbeatConfig
 
 	Sync sync.Config
+
+	// To halt when detecting the node does not support a signaled protocol version
+	// change of the given severity (major/minor/patch). Disabled if empty.
+	RollupHalt string
 }
 
 type RPCConfig struct {
@@ -128,5 +132,8 @@ func (cfg *Config) Check() error {
 			return fmt.Errorf("p2p config error: %w", err)
 		}
 	}
+	if !(cfg.RollupHalt == "" || cfg.RollupHalt == "major" || cfg.RollupHalt == "minor" || cfg.RollupHalt == "patch") {
+		return fmt.Errorf("invalid rollup halting option: %q", cfg.RollupHalt)
+	}
 	return nil
 }

op-node/node/node.go

@@ -2,7 +2,9 @@ package node
 
 import (
 	"context"
+	"errors"
 	"fmt"
+	"sync/atomic"
 	"time"
 
 	"github.com/hashicorp/go-multierror"
@@ -40,10 +42,14 @@ type OpNode struct {
 	tracer    Tracer                // tracer to get events for testing/debugging
 	runCfg    *RuntimeConfig        // runtime configurables
 
+	rollupHalt string // when to halt the rollup, disabled if empty
+
 	// some resources cannot be stopped directly, like the p2p gossipsub router (not our design),
 	// and depend on this ctx to be closed.
 	resourcesCtx   context.Context
 	resourcesClose context.CancelFunc
+
+	closed atomic.Bool
 }
 
 // The OpNode handles incoming gossip
@@ -58,6 +64,7 @@ func New(ctx context.Context, cfg *Config, log log.Logger, snapshotLog log.Logge
 		log:        log,
 		appVersion: appVersion,
 		metrics:    m,
+		rollupHalt: cfg.RollupHalt,
 	}
 	// not a context leak, gossipsub is closed with a context.
 	n.resourcesCtx, n.resourcesClose = context.WithCancel(context.Background())
@@ -189,6 +196,9 @@ func (n *OpNode) initRuntimeConfig(ctx context.Context, cfg *Config) error {
 			n.log.Error("failed to fetch runtime config data", "err", err)
 			return l1Head, err
 		}
+
+		n.handleProtocolVersionsUpdate(ctx)
+
 		return l1Head, nil
 	}
 
@@ -446,6 +456,10 @@ func (n *OpNode) RuntimeConfig() ReadonlyRuntimeConfig {
 
 // Close closes all resources.
 func (n *OpNode) Close() error {
+	if n.closed.Load() {
+		return errors.New("node is already closed")
+	}
+
 	var result *multierror.Error
 
 	if n.server != nil {
@@ -494,9 +508,18 @@ func (n *OpNode) Close() error {
 	if n.l1Source != nil {
 		n.l1Source.Close()
 	}
+
+	if result == nil { // mark as closed if we successfully fully closed
+		n.closed.Store(true)
+	}
+
 	return result.ErrorOrNil()
 }
 
+func (n *OpNode) Closed() bool {
+	return n.closed.Load()
+}
+
 func (n *OpNode) ListenAddr() string {
 	return n.server.listenAddr.String()
 }

op-node/node/runtime_config.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/params"
 
 	"github.com/ethereum-optimism/optimism/op-node/p2p"
 	"github.com/ethereum-optimism/optimism/op-node/rollup"
@@ -17,6 +18,14 @@ var (
 	// UnsafeBlockSignerAddressSystemConfigStorageSlot is the storage slot identifier of the unsafeBlockSigner
 	// `address` storage value in the SystemConfig L1 contract. Computed as `keccak256("systemconfig.unsafeblocksigner")`
 	UnsafeBlockSignerAddressSystemConfigStorageSlot = common.HexToHash("0x65a7ed542fb37fe237fdfbdd70b31598523fe5b32879e307bae27a0bd9581c08")
+
+	// RequiredProtocolVersionStorageSlot is the storage slot that the required protocol version is stored at.
+	// Computed as: `bytes32(uint256(keccak256("protocolversion.required")) - 1)`
+	RequiredProtocolVersionStorageSlot = common.HexToHash("0x4aaefe95bd84fd3f32700cf3b7566bc944b73138e41958b5785826df2aecace0")
+
+	// RecommendedProtocolVersionStorageSlot is the storage slot that the recommended protocol version is stored at.
+	// Computed as: `bytes32(uint256(keccak256("protocolversion.recommended")) - 1)`
+	RecommendedProtocolVersionStorageSlot = common.HexToHash("0xe314dfc40f0025322aacc0ba8ef420b62fb3b702cf01e0cdf3d829117ac2ff1a")
 )
 
 type RuntimeCfgL1Source interface {
@@ -25,6 +34,8 @@ type RuntimeCfgL1Source interface {
 
 type ReadonlyRuntimeConfig interface {
 	P2PSequencerAddress() common.Address
+	RequiredProtocolVersion() params.ProtocolVersion
+	RecommendedProtocolVersion() params.ProtocolVersion
 }
 
 // RuntimeConfig maintains runtime-configurable options.
@@ -49,6 +60,10 @@ type RuntimeConfig struct {
 // runtimeConfigData is a flat bundle of configurable data, easy and light to copy around.
 type runtimeConfigData struct {
 	p2pBlockSignerAddr common.Address
+
+	// superchain protocol version signals
+	recommended params.ProtocolVersion
+	required    params.ProtocolVersion
 }
 
 var _ p2p.GossipRuntimeConfig = (*RuntimeConfig)(nil)
@@ -67,18 +82,46 @@ func (r *RuntimeConfig) P2PSequencerAddress() common.Address {
 	return r.p2pBlockSignerAddr
 }
 
+func (r *RuntimeConfig) RequiredProtocolVersion() params.ProtocolVersion {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	return r.required
+}
+
+func (r *RuntimeConfig) RecommendedProtocolVersion() params.ProtocolVersion {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	return r.recommended
+}
+
 // Load resets the runtime configuration by fetching the latest config data from L1 at the given L1 block.
 // Load is safe to call concurrently, but will lock the runtime configuration modifications only,
 // and will thus not block other Load calls with possibly alternative L1 block views.
 func (r *RuntimeConfig) Load(ctx context.Context, l1Ref eth.L1BlockRef) error {
-	val, err := r.l1Client.ReadStorageAt(ctx, r.rollupCfg.L1SystemConfigAddress, UnsafeBlockSignerAddressSystemConfigStorageSlot, l1Ref.Hash)
+	p2pSignerVal, err := r.l1Client.ReadStorageAt(ctx, r.rollupCfg.L1SystemConfigAddress, UnsafeBlockSignerAddressSystemConfigStorageSlot, l1Ref.Hash)
 	if err != nil {
 		return fmt.Errorf("failed to fetch unsafe block signing address from system config: %w", err)
 	}
+	// The superchain protocol version data is optional; only applicable to rollup configs that specify a ProtocolVersions address.
+	var requiredProtVersion, recommendedProtoVersion params.ProtocolVersion
+	if r.rollupCfg.ProtocolVersionsAddress != (common.Address{}) {
+		requiredVal, err := r.l1Client.ReadStorageAt(ctx, r.rollupCfg.ProtocolVersionsAddress, RequiredProtocolVersionStorageSlot, l1Ref.Hash)
+		if err != nil {
+			return fmt.Errorf("required-protocol-version value failed to load from L1 contract: %w", err)
+		}
+		requiredProtVersion = params.ProtocolVersion(requiredVal)
+		recommendedVal, err := r.l1Client.ReadStorageAt(ctx, r.rollupCfg.ProtocolVersionsAddress, RecommendedProtocolVersionStorageSlot, l1Ref.Hash)
+		if err != nil {
+			return fmt.Errorf("recommended-protocol-version value failed to load from L1 contract: %w", err)
+		}
+		recommendedProtoVersion = params.ProtocolVersion(recommendedVal)
+	}
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	r.l1Ref = l1Ref
-	r.p2pBlockSignerAddr = common.BytesToAddress(val[:])
+	r.p2pBlockSignerAddr = common.BytesToAddress(p2pSignerVal[:])
+	r.required = requiredProtVersion
+	r.recommended = recommendedProtoVersion
 	r.log.Info("loaded new runtime config values!", "p2p_seq_address", r.p2pBlockSignerAddr)
 	return nil
 }

op-node/node/superchain.go

+package node
+
+import (
+	"context"
+
+	"github.com/ethereum-optimism/optimism/op-node/rollup"
+	"github.com/ethereum/go-ethereum/eth/catalyst"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+func (n *OpNode) handleProtocolVersionsUpdate(ctx context.Context) {
+	recommended := n.runCfg.RecommendedProtocolVersion()
+	required := n.runCfg.RequiredProtocolVersion()
+	// if the protocol version sources are disabled we do not process them
+	if recommended == (params.ProtocolVersion{}) && required == (params.ProtocolVersion{}) {
+		return
+	}
+	local := rollup.OPStackSupport
+	// forward to execution engine, and get back the protocol version that op-geth supports
+	engineSupport, err := n.l2Source.SignalSuperchainV1(ctx, recommended, required)
+	if err != nil {
+		n.log.Warn("failed to notify engine of protocol version", "err", err)
+		// engineSupport may still be available, or otherwise zero to signal as unknown
+	} else {
+		catalyst.LogProtocolVersionSupport(n.log.New("node", "op-node"), engineSupport, recommended, "recommended")
+		catalyst.LogProtocolVersionSupport(n.log.New("node", "op-node"), engineSupport, required, "required")
+	}
+	n.metrics.ReportProtocolVersions(local, engineSupport, recommended, required)
+	catalyst.LogProtocolVersionSupport(n.log.New("node", "engine"), local, recommended, "recommended")
+	catalyst.LogProtocolVersionSupport(n.log.New("node", "engine"), local, required, "required")
+
+	// We may need to halt the node, if the user opted in to handling incompatible protocol-version signals
+	n.HaltMaybe()
+}
+
+// HaltMaybe halts the rollup node if the runtime config indicates an incompatible required protocol change
+// and the node is configured to opt-in to halting at this protocol-change level.
+func (n *OpNode) HaltMaybe() {
+	var needLevel int
+	switch n.rollupHalt {
+	case "major":
+		needLevel = 3
+	case "minor":
+		needLevel = 2
+	case "patch":
+		needLevel = 1
+	default:
+		return // do not consider halting if not configured to
+	}
+	haveLevel := 0
+	local := rollup.OPStackSupport
+	required := n.runCfg.RequiredProtocolVersion()
+	switch local.Compare(required) {
+	case params.OutdatedMajor:
+		haveLevel = 3
+	case params.OutdatedMinor:
+		haveLevel = 2
+	case params.OutdatedPatch:
+		haveLevel = 1
+	}
+	if haveLevel >= needLevel { // halt if we opted in to do so at this granularity
+		n.log.Error("opted to halt, unprepared for protocol change", "required", required, "local", local)
+		if err := n.Close(); err != nil {
+			n.log.Error("failed to halt rollup", "err", err)
+		}
+	}
+}

op-node/rollup/superchain.go

@@ -4,12 +4,16 @@ import (
 	"fmt"
 	"math/big"
 
+	"github.com/ethereum/go-ethereum/params"
+
 	"github.com/ethereum/go-ethereum/common"
 
 	"github.com/ethereum-optimism/optimism/op-service/eth"
 	"github.com/ethereum-optimism/superchain-registry/superchain"
 )
 
+var OPStackSupport = params.ToProtocolVersion([8]byte{}, 3, 1, 0, 1)
+
 const (
 	opMainnet   = 10
 	opGoerli    = 420

op-node/rollup/types.go

@@ -84,6 +84,9 @@ type Config struct {
 	DepositContractAddress common.Address `json:"deposit_contract_address"`
 	// L1 System Config Address
 	L1SystemConfigAddress common.Address `json:"l1_system_config_address"`
+
+	// L1 address that declares the protocol versions, optional (Beta feature)
+	ProtocolVersionsAddress common.Address `json:"protocol_versions_address,omitempty"`
 }
 
 // ValidateL1Config checks L1 config variables for errors.
@@ -283,6 +286,8 @@ func (c *Config) Description(l2Chains map[string]string) string {
 	// Report the upgrade configuration
 	banner += "Post-Bedrock Network Upgrades (timestamp based):\n"
 	banner += fmt.Sprintf("  - Regolith: %s\n", fmtForkTimeOrUnset(c.RegolithTime))
+	// Report the protocol version
+	banner += fmt.Sprintf("Node supports up to OP-Stack Protocol Version: %s\n", OPStackSupport)
 	return banner
 }
 

op-node/service.go

@@ -36,6 +36,10 @@ func NewConfig(ctx *cli.Context, log log.Logger) (*node.Config, error) {
 		return nil, err
 	}
 
+	if !ctx.Bool(flags.BetaRollupLoadProtocolVersions.Name) {
+		rollupConfig.ProtocolVersionsAddress = common.Address{}
+	}
+
 	configPersistence := NewConfigPersistence(ctx)
 
 	driverConfig := NewDriverConfig(ctx)
@@ -61,6 +65,11 @@ func NewConfig(ctx *cli.Context, log log.Logger) (*node.Config, error) {
 
 	syncConfig := NewSyncConfig(ctx)
 
+	haltOption := ctx.String(flags.BetaRollupHalt.Name)
+	if haltOption == "none" {
+		haltOption = ""
+	}
+
 	cfg := &node.Config{
 		L1:     l1Endpoint,
 		L2:     l2Endpoint,
@@ -93,6 +102,7 @@ func NewConfig(ctx *cli.Context, log log.Logger) (*node.Config, error) {
 		},
 		ConfigPersistence: configPersistence,
 		Sync:              *syncConfig,
+		RollupHalt:        haltOption,
 	}
 
 	if err := cfg.LoadPersisted(log); err != nil {

op-node/sources/engine_client.go

@@ -5,6 +5,9 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/ethereum/go-ethereum/eth/catalyst"
+	"github.com/ethereum/go-ethereum/params"
+
 	"github.com/ethereum-optimism/optimism/op-node/client"
 	"github.com/ethereum-optimism/optimism/op-node/rollup"
 	"github.com/ethereum-optimism/optimism/op-node/sources/caching"
@@ -125,3 +128,12 @@ func (s *EngineClient) GetPayload(ctx context.Context, payloadId eth.PayloadID)
 	e.Trace("Received payload")
 	return &result, nil
 }
+
+func (s *EngineClient) SignalSuperchainV1(ctx context.Context, recommended, required params.ProtocolVersion) (params.ProtocolVersion, error) {
+	var result params.ProtocolVersion
+	err := s.client.CallContext(ctx, &result, "engine_signalSuperchainV1", &catalyst.SuperchainSignal{
+		Recommended: recommended,
+		Required:    required,
+	})
+	return result, err
+}

op-service/eth/account_proof.go

@@ -51,6 +51,9 @@ func (res *AccountResult) Verify(stateRoot common.Hash) error {
 		if err != nil {
 			return fmt.Errorf("failed to verify storage value %d with key %s (path %x) in storage trie %s: %w", i, entry.Key, path, res.StorageHash, err)
 		}
+		if val == nil && entry.Value.ToInt().Cmp(common.Big0) == 0 { // empty storage is zero by default
+			continue
+		}
 		comparison, err := rlp.EncodeToBytes(entry.Value.ToInt().Bytes())
 		if err != nil {
 			return fmt.Errorf("failed to encode storage value %d with key %s (path %x) in storage trie %s: %w", i, entry.Key, path, res.StorageHash, err)