Add Linea pusher and buffer #59

luiz-lvj · 2026-01-16T15:47:49Z

Add Linea Chain Support to Block Hash Pusher

This PR adds support for Linea L2 to the block hash pusher system, enabling Ethereum L1 block hashes to be pushed to Linea L2.

Contracts:

LineaPusher - L1 contract that pushes block hashes to Linea L2 via Linea Rollup.sendMessage()
LineaBuffer - L2 contract that receives and stores block hashes with access control via L2MessageService

PS: this PR must be merged after #56 and #57

Summary by CodeRabbit

New Features
- Added support for pushing block hashes between Linea L1 and L2 networks
- Integrated cross-chain messaging functionality with configurable access controls
Documentation
- Updated Block Hash Pusher documentation with Linea integration details

_{✏️ Tip: You can customize this high-level summary in your review settings.}

…caster into linea-pusher

coderabbitai · 2026-01-16T15:48:00Z

📝 Walkthrough

Walkthrough

Adds Linea network support to the block hash pusher system by introducing a new submodule, creating LineaPusher and LineaBuffer contracts for L1-to-L2 cross-chain communication, updating import mappings, and providing comprehensive tests and documentation.

Changes

Cohort / File(s)	Summary
Submodule and Import Configuration `.gitmodules`, `lib/linea-monorepo`, `remappings.txt`	Adds linea-monorepo submodule entry and creates import mapping for `@linea-contracts` pointing to the submodule's contracts directory.
Linea Buffer Contract `src/contracts/block-hash-pusher/linea/LineaBuffer.sol`	New L2 contract extending BaseBuffer for receiving and storing L1 block hashes. Implements access control via L2 MessageService, allows one-time pusher configuration by owner, and includes comprehensive error handling.
Linea Pusher Contract `src/contracts/block-hash-pusher/linea/LineaPusher.sol`	New L1 contract extending BlockHashArrayBuilder for pushing batched block hashes to L2 via Linea's messaging service. Encodes calldata and handles L2 transaction fees through immutable references to the rollup and buffer addresses.
Documentation `src/contracts/block-hash-pusher/README.md`	Adds Linea section documenting deployment, access control, required addresses, configuration, and message flow for LineaPusher and LineaBuffer.
LineaBuffer Tests `test/block-hash-pusher/linea/LineaBuffer.t.sol`	Comprehensive test suite covering hash reception, sender validation, pusher address management, and access control with fuzzing and revert scenarios.
LineaPusher Tests `test/block-hash-pusher/linea/LineaPusher.t.sol`	Test suite validating pushHashes behavior including fork testing, fuzzing, value sufficiency checks, batch size validation, and view function correctness.
Mock Linea Message Service `test/block-hash-pusher/mocks/MockLineaMessageService.sol`	Mock implementation of IMessageService and IClaimMessageV1 for testing, supporting message sending and claiming with sender context management and calldata execution.

Sequence Diagram(s)

sequenceDiagram
    actor User
    participant L1 as LineaPusher<br/>(L1)
    participant MessageService as Linea<br/>MessageService
    participant L2 as LineaBuffer<br/>(L2)
    
    User->>L1: pushHashes(firstBlock, batchSize, l2TxData)
    L1->>L1: Build block hash array
    L1->>L1: Encode receiveHashes calldata
    L1->>MessageService: sendMessage(buffer, fee, calldata)
    MessageService->>MessageService: Store & emit MessageSent
    
    Note over MessageService: L2 message relay
    
    MessageService->>L2: claimMessage(...) 
    L2->>L2: Verify sender == MessageService
    L2->>L2: Extract pusher from MessageService
    L2->>L2: Validate pusher address matches
    L2->>L2: Store block hashes
    L2->>MessageService: Emit MessageClaimed
    MessageService->>L1: Message execution confirmed
    L1->>L1: Emit BlockHashesPushed

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~30 minutes

Suggested reviewers

pepebndc
nahimterrazas
frangio

Poem

🐇 A Linea is drawn, from L1 to L2,
Through forests of hashes, both old and new,
With buffers and pushers in harmony bound,
Cross-chain block storage—on Linea found! 📦✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'Add Linea pusher and buffer' directly and concisely summarizes the main change: introducing two new Linea-related contracts (LineaPusher and LineaBuffer) to support pushing block hashes to Linea L2.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

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nahimterrazas · 2026-01-20T23:01:22Z

src/contracts/block-hash-pusher/BaseBuffer.sol

+pragma solidity 0.8.30;
+
+import {IBuffer} from "./interfaces/IBuffer.sol";
+import {AddressAliasHelper} from "@arbitrum/nitro-contracts/src/libraries/AddressAliasHelper.sol";


I think this is not used

nahimterrazas · 2026-01-20T23:07:38Z

src/contracts/block-hash-pusher/scroll/ScrollBuffer.sol

+    }
+
+    /// @inheritdoc IBuffer
+    function receiveHashes(uint256 firstBlockNumber, bytes32[] calldata blockHashes) external {


on the interface blockHashes is memory, here is calldata

Thanks, changed it to calldata

…caster into linea-pusher

frangio · 2026-01-23T14:24:16Z

src/contracts/block-hash-pusher/linea/LineaBuffer.sol

+    address private _pusherAddress;
+
+    /// @notice Thrown when attempting to receive hashes before the pusher address has been set.
+    error PusherAddressNotSet();


There seem to be a few errors and events that show up in every Buffer. Perhaps those should be moved to IBuffer?

…to linea-pusher

coderabbitai

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@src/contracts/block-hash-pusher/linea/LineaPusher.sol`:
- Around line 27-30: Add explicit zero-address checks in the constructor to fail
fast if rollup_ or bufferAddress_ is address(0). In the constructor of
LineaPusher.sol, validate rollup_ and bufferAddress_ with require(rollup_ !=
address(0), "...") and require(bufferAddress_ != address(0), "...") before
assigning to _lineaRollup and _bufferAddress, using clear revert messages that
identify the bad parameter (e.g., "LineaPusher: rollup is zero address" and
"LineaPusher: buffer is zero address").

🧹 Nitpick comments (2)

src/contracts/block-hash-pusher/linea/LineaBuffer.sol (1)

20-51: Consider making _l2MessageService immutable.
It’s constructor-only state, so immutable saves storage reads and locks the invariant.

♻️ Proposed refactor

-    address private _l2MessageService;
+    address private immutable _l2MessageService;

-    constructor(address l2MessageService_, address initialOwner_) Ownable(initialOwner_) {
-        _l2MessageService = l2MessageService_;
-
-        if (l2MessageService_ == address(0)) {
-            revert InvalidL2MessageServiceAddress();
-        }
-    }
+    constructor(address l2MessageService_, address initialOwner_) Ownable(initialOwner_) {
+        if (l2MessageService_ == address(0)) {
+            revert InvalidL2MessageServiceAddress();
+        }
+        _l2MessageService = l2MessageService_;
+    }

test/block-hash-pusher/linea/LineaBuffer.t.sol (1)

45-56: Unused l2Calldata variable.

Line 51 creates l2Calldata but it's not used since the test calls receiveHashes directly. This is a minor cleanup opportunity.

♻️ Suggested cleanup

     function testFuzz_receiveHashes_reverts_if_sender_is_not_linea_message_service(address notLineaMessageService)
         public
     {
         vm.assume(notLineaMessageService != address(mockLineaMessageService));
         LineaBuffer buffer = new LineaBuffer(address(mockLineaMessageService), owner);
 
-        bytes memory l2Calldata = abi.encodeCall(buffer.receiveHashes, (1, new bytes32[](1)));
-
         vm.expectRevert(abi.encodeWithSelector(LineaBuffer.InvalidSender.selector));
         vm.prank(notLineaMessageService);
         buffer.receiveHashes(1, new bytes32[](1));
     }

coderabbitai · 2026-01-23T14:36:11Z

src/contracts/block-hash-pusher/linea/LineaPusher.sol

+    constructor(address rollup_, address bufferAddress_) {
+        _lineaRollup = rollup_;
+        _bufferAddress = bufferAddress_;
+    }


⚠️ Potential issue | 🟠 Major

Add zero-address checks for rollup and buffer.
Fail fast on misconfiguration to avoid sending messages to address(0).

🐛 Proposed fix

constructor(address rollup_, address bufferAddress_) { + require(rollup_ != address(0) && bufferAddress_ != address(0), "LineaPusher: zero address"); _lineaRollup = rollup_; _bufferAddress = bufferAddress_; }

🤖 Prompt for AI Agents

In `@src/contracts/block-hash-pusher/linea/LineaPusher.sol` around lines 27 - 30, Add explicit zero-address checks in the constructor to fail fast if rollup_ or bufferAddress_ is address(0). In the constructor of LineaPusher.sol, validate rollup_ and bufferAddress_ with require(rollup_ != address(0), "...") and require(bufferAddress_ != address(0), "...") before assigning to _lineaRollup and _bufferAddress, using clear revert messages that identify the bad parameter (e.g., "LineaPusher: rollup is zero address" and "LineaPusher: buffer is zero address").

luiz-lvj added 12 commits January 15, 2026 14:22

install linea

a5fde7f

add remappings.txt

8944f7e

add Linea Buffer and Pusher contracts

be1f9d8

Merge branch 'scroll-pusher' of github.com:openintentsframework/broad…

e5e445a

…caster into linea-pusher

update pragma to 0.8.30

84c16e5

add mock service

8115f64

Merge branch 'scroll-pusher' of github.com:openintentsframework/broad…

3a11538

…caster into linea-pusher

up

c0a1351

up

1435a62

up

aeb14ca

update natspec

698ee32

update README

296d96d

luiz-lvj requested review from nahimterrazas and pepebndc January 16, 2026 15:47

luiz-lvj requested a review from frangio January 16, 2026 15:48

update mock

6146cf8

nahimterrazas reviewed Jan 20, 2026

View reviewed changes

luiz-lvj added 3 commits January 22, 2026 16:32

Merge branch 'scroll-pusher' of github.com:openintentsframework/broad…

87d7060

…caster into linea-pusher

Merge branch 'scroll-pusher' of github.com:openintentsframework/broad…

41309b8

…caster into linea-pusher

update contracts

cc9c647

frangio reviewed Jan 23, 2026

View reviewed changes

Merge branch 'main' of github.com:openintentsframework/broadcaster in…

a8be7bc

…to linea-pusher

luiz-lvj marked this pull request as ready for review January 23, 2026 14:26

frangio approved these changes Jan 23, 2026

View reviewed changes

coderabbitai bot reviewed Jan 23, 2026

View reviewed changes

luiz-lvj merged commit 6599163 into main Jan 23, 2026
3 checks passed

coderabbitai bot mentioned this pull request Jan 23, 2026

Update pushHashes function signature #60

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Add Linea pusher and buffer #59

Add Linea pusher and buffer #59

luiz-lvj commented Jan 16, 2026 •

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Add Linea pusher and buffer #59

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Add Linea Chain Support to Block Hash Pusher

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