Pre-checker tx filtering (using estimate gas call) by MishkaRogachev · Pull Request #4583 · OffchainLabs/nitro

MishkaRogachev · 2026-03-30T16:08:43Z

fixes NIT-4344
Pulls in OffchainLabs/go-ethereum#643

Add address filtering to TxPreChecker via gas estimation dry-run. Pre-checker now runs transactions through gasestimator.Run to detect filtered addresses before forwarding, catching sender/recipient, aliased, retryable, and event-based address matches including cascading redeems.

….PostTxFilter

…n-api

…ictnessNone

…n-api

…n-api-2

… gas_estimate

diegoximenes · 2026-04-02T15:07:28Z


+type TransactionFilteringConfig struct {
+	DisableDelayedSequencingFilter bool                          `koanf:"disable-delayed-sequencing-filter"`
+	EnableRPCFilter                bool                          `koanf:"enable-rpc-filter"`


EnableRPCFilter is too generic to me, since publishing a transaction also happens through RPC.
I am inclined on using EnableNonMutatingRPCFilter, but I think Tsahi doesn't like it.
I will let @tsahee decide that.

Suggested change

EnableRPCFilter bool `koanf:"enable-rpc-filter"`

EnableNonMutatingRPCFilter bool `koanf:"enable-non-mutating-rpc-filter"`

I indeed don't like non-mutating. enable-ethcall-filter? I know it's not exact but much more self-explanatory.

It should be identical to: https://github.com/OffchainLabs/nitro/pull/4591/changes

Renamed to enable-ethcall-filter

diegoximenes · 2026-04-02T16:46:08Z

 	if err != nil {
 		return err
 	}
+	if err := c.checkFilteredAddresses(tx, block); err != nil {


checkFilteredAddresses could be done in the beginning of PreCheckTx to avoid that.
But fully running current PreCheckTx can avoid unnecessary gas estimation anyway.

diegoximenes · 2026-04-02T18:18:24Z

+}
+
+func (f *txFilterer) TouchAddresses(statedb *state.StateDB, tx *types.Transaction, sender common.Address) {
+	touchAddresses(statedb, nil, tx, sender)


These are retryables, so we need the full set: aliased sender and retryable-specific fields. The regular preTxFilter's from/to-only approach would miss those.

Current scenario:

For delayed sequencing, the post tx filter calls touchRetryableAddresses, to handle ArbitrumSubmitRetryableTx in a special way. It also handles "TxTypeAlias" in a special way.

For regular transaction sequencing, touchRetryableAddresses is not called, ArbitrumSubmitRetryableTx is not handled in a special way in any step of the filtering process.

For pre-checker/eth_estimateGas we are enforcing to use the same policy as the delayed sequencing.

All those scenarios handle scheduled transactions.

At this point this is confusing to me.
I don't understand if regular transaction sequencing has an issue right now, and it should actually handle ArbitrumSubmitRetryableTx in a special way.
Or if we are enforcing this ArbitrumSubmitRetryableTx handling in eth_estimateGas unnecessarily, which doesn't seem create wrong results, but the whole inconsistency is causing me confusion.
I will let the way it is right now, but depending on the reason we should revisit it in another task to clean up this inconsistency.

@tsahee am I missing something?

tsahee · 2026-04-02T23:14:24Z

+	if n.AddressFilterService != nil {
+		n.AddressFilterService.Start(ctx)
+		checker := n.AddressFilterService.GetAddressChecker()
+		n.ExecEngine.SetAddressChecker(checker)


is this o.k. in this order?

I think we need to move get/set address checker to (n *ExecutionNode) Initialize, and then ExecEngine, when started, will know it has an addresschecker (so it could do things like refuse transactions while the filter is not initialized)

Now addressChecker is provided to ExecutionEngine through NewExecutionEngine.
n.ExecEngine.SetAddressChecker still exists, but only used by tests.

so it could do things like refuse transactions while the filter is not initialized

You mean the prechecker should refuse a transaction while the S3 file wasn't downloaded yet?
If so I think the load balancer should avoid sending a transaction to a prechecker that is not synced yet, and to decided if it is synced it should consider if it downloaded the S3 file already?
Same reasoning for nodes handling eth_call and eth_estimateGas.

tsahee · 2026-04-02T23:33:09Z

+}
+
+func (f *txFilterer) TouchAddresses(statedb *state.StateDB, tx *types.Transaction, sender common.Address) {
+	touchAddresses(statedb, nil, tx, sender)


So the event filter will be added in checkFiltered and de-facto will enforce the same policy as normal transactions. But it deserves more thought and possibly renaming

tsahee · 2026-04-03T23:31:07Z

-	if tx.Type() == types.ArbitrumInternalTxType {
-		return nil
-	}
+func touchAddresses(db *state.StateDB, ef *eventfilter.EventFilter, tx *types.Transaction, sender common.Address) {


I think Diego's (justified) confusion comes from the fact that this function tries to do two things:
both "touch addresses" and apply event filter, while the function with the same name in core.TxFilterer only does one of those things, and eventFilter is applied later.

Either remove eventFilter from touchAddresses, or make the two funcs have different names.

My confusion is a little bit more than that.
It is also the fact that both eth_estimateGas and delayed filtering handle ArbitrumSubmitRetryableTx in a different way than regular sequencing.
I can see a world where only delayed sequencing filters ArbitrumSubmitRetryableTx differently compared to eth_estimateGas and regular sequencing, or a world in which all of them handle ArbitrumSubmitRetryableTx in the same way.

I added a commit that make all kinds of filtering (delayed sequencing, eth_estimateGas, regular sequencing) handle ArbitrumSubmitRetryableTx.

ArbitrumSubmitRetryableTx can only come from a L1, I don't think there is a way to create it with eth_call or eth_stimateGas

tsahee · 2026-04-03T23:40:57Z

 	if config.Sequencer.Enable {
 		seqConfigFetcher := func() *SequencerConfig { return &configFetcher.Get().Sequencer }
-		sequencer, err = NewSequencer(execEngine, parentChainReader, seqConfigFetcher, seqParentChain)
+		if config.TransactionFiltering.TransactionFiltererRPCClient.URL != "" {


not critical for this PR - but reporting will also move and will also cover (at least) prechecker

As discussed out of GitHub, for reporting precheckers/sequencers will call cmd/filtering-report instead.

tsahee · 2026-04-03T23:43:41Z

+	if n.AddressFilterService != nil {
+		n.AddressFilterService.Start(ctx)
+		checker := n.AddressFilterService.GetAddressChecker()
+		n.ExecEngine.SetAddressChecker(checker)


I think we need to move get/set address checker to (n *ExecutionNode) Initialize, and then ExecEngine, when started, will know it has an addresschecker (so it could do things like refuse transactions while the filter is not initialized)

tsahee

LGTM

MishkaRogachev and others added 23 commits March 2, 2026 15:58

Prechecker address filtering, mirrors DelayedFilteringSequencingHooks…

494c6ba

….PostTxFilter

Support redeems filtering in preCheckAddressFilter

a07f255

Refactor address touching in execution path to reuse in prechecker

27f5611

Merge remote-tracking branch 'origin/master' into prefilter-blockchai…

ae331b2

…n-api

Handle cascading redeems filtering on pre-checker path

0fa289f

Refactor duplication in preCheckAddressFilter

96dd07e

Merge branch 'master' into prefilter-blockchain-api

61e6bcb

Limit gas usage for pre-checker filtering and improve warnings

e6c5b4c

Move defaultSpeculativeFilterGasCap to config

36f4ab2

Remove artificial gas cap

a31a18c

Merge branch 'master' into prefilter-blockchain-api

c634be1

Improve TestPrecheckerFilterCascadingRedeemDepthN tests

844c9c7

Review fixes

b59cc31

Merge remote-tracking branch 'origin/master' into prefilter-blockchai…

bd4eeab

…n-api

Use real gas limit for filtering on the pre-checker

40ebc29

Move filtering config to gethexec and reuse it for prechecker

ada54be

Prechecker skips address filtering when strictness is TxPreCheckerStr…

8398ff4

…ictnessNone

Fix TestSyncBlockedUntilFilteringReady for gethexec config change

2f54a4f

Merge remote-tracking branch 'origin/master' into prefilter-blockchai…

7139535

…n-api

Merge remote-tracking branch 'origin/master' into prefilter-blockchai…

3765d49

…n-api

Make pre-checker use gasestimator.Run for filtering

b749e7d

Replace precheckerBackend with node backend

992c0d8

Simplify pre-checker wiring for tx filtering

78d9069

MishkaRogachev mentioned this pull request Mar 30, 2026

core: TxFilterer interface for address-based transaction filtering in gas estimation OffchainLabs/go-ethereum#643

Merged

MishkaRogachev added 4 commits March 30, 2026 20:29

Remove tails from presvious impl

87d7d9c

Move tx filter to APIBackend

a4f6e19

Merge remote-tracking branch 'origin/master' into prefilter-blockchai…

ab5fae9

…n-api-2

Add GasLimit for retryable filtering tests to skip eraly filtering in…

2b91fd1

… gas_estimate

MishkaRogachev force-pushed the prefilter-blockchain-api-2 branch from 91af9cf to 2b91fd1 Compare March 31, 2026 15:18

MishkaRogachev requested a review from diegoximenes March 31, 2026 15:31

diegoximenes added 3 commits April 2, 2026 14:02

Removes outdated comment.

29033fb

Disable RPC filter for all tests by default

0b66c8b

Adds estimate gas filter test

40bfadd

diegoximenes requested changes Apr 2, 2026

View reviewed changes

Merge branch 'master' into prefilter-blockchain-api-2

0c9ab80

diegoximenes previously approved these changes Apr 2, 2026

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diegoximenes assigned tsahee and unassigned diegoximenes Apr 2, 2026

tsahee reviewed Apr 2, 2026

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tsahee reviewed Apr 3, 2026

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diegoximenes added 6 commits April 6, 2026 12:29

Merge branch 'master' into prefilter-blockchain-api-2

4521b64

enable-ethcall-filter instead of enable-rpc-filter

8e449cd

Pass addressChecker to NewExecutionEngine

f0e8f2c

Fix EnableRPCFilterleftovers

1695dd3

Removes event filter from touchAddresses

e4851e1

Also uses touchAddresses in Sequencer.preTxFilter

59326f9

diegoximenes mentioned this pull request Apr 6, 2026

Pre-checker tx filtering (ApplyTransactionWithEVM-based dry run) #4444

Closed

3 tasks

diegoximenes added 3 commits April 6, 2026 14:20

Fix NewExecutionEngine call

ff4b878

Fixes addressChecker assignment

6e9c4b3

Fix addressChecker type

4287cf8

diegoximenes dismissed their stale review via 4287cf8 April 6, 2026 18:07

diegoximenes added 2 commits April 6, 2026 15:10

Removes unwanted file

3e4ec0b

Remove EnableFiltering

a04d769

tsahee approved these changes Apr 6, 2026

View reviewed changes

tsahee added the design-approved label Apr 6, 2026

tsahee enabled auto-merge April 6, 2026 21:37

tsahee added this pull request to the merge queue Apr 6, 2026

Merged via the queue into master with commit 68da2ed Apr 6, 2026
43 of 44 checks passed

tsahee deleted the prefilter-blockchain-api-2 branch April 6, 2026 22:31

	EnableRPCFilter bool `koanf:"enable-rpc-filter"`
	EnableNonMutatingRPCFilter bool `koanf:"enable-non-mutating-rpc-filter"`

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MishkaRogachev commented Mar 30, 2026

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diegoximenes Apr 6, 2026 •

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