Files
smom-dbis-138/contracts/bridge/trustless/BondManager.sol
2026-03-02 12:14:09 -08:00

274 lines
9.5 KiB
Solidity

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
/**
* @title BondManager
* @notice Manages bonds for trustless bridge claims with dynamic sizing and slashing
* @dev Bonds are posted in ETH. Slashed bonds split 50% to challenger, 50% burned (sent to address(0)).
*/
contract BondManager is ReentrancyGuard {
// Bond configuration
uint256 public immutable bondMultiplier; // Basis points (11000 = 110%)
uint256 public immutable minBond; // Minimum bond amount in wei
// Bond tracking
struct Bond {
address relayer; // Slot 0 (20 bytes) + 12 bytes padding
uint256 amount; // Slot 1
uint256 depositId; // Slot 2
bool slashed; // Slot 3 (1 byte) + 31 bytes padding
bool released; // Slot 4 (1 byte) + 31 bytes padding
// Note: Could pack slashed and released in same slot, but keeping separate for clarity
}
mapping(uint256 => Bond) public bonds; // depositId => Bond
mapping(address => uint256) public totalBonds; // relayer => total bonded amount
/// @notice Total ETH held in active (non-released, non-slashed) bonds. Used for value-conservation invariant.
uint256 public totalEthHeld;
event BondPosted(
uint256 indexed depositId,
address indexed relayer,
uint256 bondAmount
);
event BondSlashed(
uint256 indexed depositId,
address indexed relayer,
address indexed challenger,
uint256 bondAmount,
uint256 challengerReward,
uint256 burnedAmount
);
event BondReleased(
uint256 indexed depositId,
address indexed relayer,
uint256 bondAmount
);
error ZeroDepositId();
error ZeroRelayer();
error InsufficientBond();
error BondNotFound();
error BondAlreadySlashed();
error BondAlreadyReleased();
error BondNotReleased();
/**
* @notice Constructor sets bond parameters
* @param _bondMultiplier Bond multiplier in basis points (11000 = 110% = 1.1x)
* @param _minBond Minimum bond amount in wei
*/
constructor(uint256 _bondMultiplier, uint256 _minBond) {
require(_bondMultiplier >= 10000, "BondManager: multiplier must be >= 100%");
require(_minBond > 0, "BondManager: minBond must be > 0");
bondMultiplier = _bondMultiplier;
minBond = _minBond;
}
/**
* @notice Post bond for a claim
* @param depositId Deposit ID from source chain
* @param depositAmount Amount of the deposit (used to calculate bond size)
* @param relayer Address of the relayer posting the bond (can be different from msg.sender if called by InboxETH)
* @return bondAmount The bond amount that was posted
*/
function postBond(
uint256 depositId,
uint256 depositAmount,
address relayer
) external payable nonReentrant returns (uint256) {
if (depositId == 0) revert ZeroDepositId();
if (relayer == address(0)) revert ZeroRelayer();
// Check if bond already exists
require(bonds[depositId].relayer == address(0), "BondManager: bond already posted");
// Calculate required bond amount
uint256 requiredBond = getRequiredBond(depositAmount);
if (msg.value < requiredBond) revert InsufficientBond();
// Store bond information
bonds[depositId] = Bond({
relayer: relayer,
amount: msg.value,
depositId: depositId,
slashed: false,
released: false
});
totalBonds[relayer] += msg.value;
totalEthHeld += msg.value;
emit BondPosted(depositId, msg.sender, msg.value);
return msg.value;
}
/**
* @notice Slash bond due to fraudulent claim
* @param depositId Deposit ID associated with the bond
* @param challenger Address of the challenger proving fraud
* @return challengerReward Amount sent to challenger
* @return burnedAmount Amount burned (sent to address(0))
*/
function slashBond(
uint256 depositId,
address challenger
) external nonReentrant returns (uint256 challengerReward, uint256 burnedAmount) {
Bond storage bond = bonds[depositId];
if (bond.relayer == address(0)) revert BondNotFound();
if (bond.slashed) revert BondAlreadySlashed();
if (challenger == address(0)) revert ZeroRelayer();
// Mark bond as slashed
bond.slashed = true;
uint256 bondAmount = bond.amount;
// Update relayer's total bonds and total ETH held
totalBonds[bond.relayer] -= bondAmount;
totalEthHeld -= bondAmount;
// Split bond: 50% to challenger, 50% burned
challengerReward = bondAmount / 2;
burnedAmount = bondAmount - challengerReward; // Handle odd amounts
// Transfer to challenger
(bool success1, ) = payable(challenger).call{value: challengerReward}("");
require(success1, "BondManager: challenger transfer failed");
// Burn remaining amount (send to address(0))
// Note: In practice, sending ETH to address(0) doesn't actually burn it,
// but it makes the funds inaccessible. For true burning, consider using a burn mechanism.
(bool success2, ) = payable(address(0)).call{value: burnedAmount}("");
require(success2, "BondManager: burn transfer failed");
emit BondSlashed(
depositId,
bond.relayer,
challenger,
bondAmount,
challengerReward,
burnedAmount
);
return (challengerReward, burnedAmount);
}
/**
* @notice Release bond after successful claim finalization
* @param depositId Deposit ID associated with the bond
* @return bondAmount Amount returned to relayer
*/
function releaseBond(
uint256 depositId
) external nonReentrant returns (uint256) {
Bond storage bond = bonds[depositId];
if (bond.relayer == address(0)) revert BondNotFound();
if (bond.slashed) revert BondAlreadySlashed();
if (bond.released) revert BondAlreadyReleased();
// Mark bond as released
bond.released = true;
uint256 bondAmount = bond.amount;
address relayer = bond.relayer; // Cache to save gas
// Update relayer's total bonds
totalBonds[relayer] -= bondAmount;
// Transfer bond back to relayer
(bool success, ) = payable(relayer).call{value: bondAmount}("");
require(success, "BondManager: release transfer failed");
emit BondReleased(depositId, relayer, bondAmount);
return bondAmount;
}
/**
* @notice Release multiple bonds in batch (gas optimization)
* @param depositIds Array of deposit IDs to release bonds for
* @return totalReleased Total amount released
*/
function releaseBondsBatch(uint256[] calldata depositIds) external nonReentrant returns (uint256 totalReleased) {
uint256 length = depositIds.length;
require(length > 0, "BondManager: empty array");
require(length <= 50, "BondManager: batch too large"); // Prevent gas limit issues
for (uint256 i = 0; i < length; i++) {
uint256 depositId = depositIds[i];
if (depositId == 0) continue; // Skip zero IDs
Bond storage bond = bonds[depositId];
if (bond.relayer == address(0)) continue; // Skip non-existent bonds
if (bond.slashed) continue; // Skip slashed bonds
if (bond.released) continue; // Skip already released
bond.released = true;
uint256 bondAmount = bond.amount;
address relayer = bond.relayer; // Cache to save gas
totalBonds[relayer] -= bondAmount;
totalEthHeld -= bondAmount;
totalReleased += bondAmount;
(bool success, ) = payable(relayer).call{value: bondAmount}("");
require(success, "BondManager: release transfer failed");
emit BondReleased(depositId, relayer, bondAmount);
}
return totalReleased;
}
/**
* @notice Calculate required bond amount for a deposit
* @param depositAmount Amount of the deposit
* @return requiredBond Minimum bond amount required
*/
function getRequiredBond(uint256 depositAmount) public view returns (uint256) {
uint256 calculatedBond = (depositAmount * bondMultiplier) / 10000;
return calculatedBond > minBond ? calculatedBond : minBond;
}
/**
* @notice Get bond information for a deposit
* @param depositId Deposit ID to check
* @return relayer Address that posted the bond
* @return amount Bond amount
* @return slashed Whether bond has been slashed
* @return released Whether bond has been released
*/
function getBond(
uint256 depositId
) external view returns (
address relayer,
uint256 amount,
bool slashed,
bool released
) {
Bond memory bond = bonds[depositId];
return (bond.relayer, bond.amount, bond.slashed, bond.released);
}
/**
* @notice Get total bonds posted by a relayer
* @param relayer Address to check
* @return Total amount of bonds posted
*/
function getTotalBonds(address relayer) external view returns (uint256) {
return totalBonds[relayer];
}
// Allow contract to receive ETH
receive() external payable {}
}