remove status and minStake (#401)

This PR removes the minStake and status from the GATEWAY contracts. 

Previously we had this as we only have collateral based PermissionMode
and the idea is to use these parameters to control in the Gateway to
enforce some control over different subnets. But now we are moving
towards different `PermissionMode` and these parameters no longer
required.

Note that `minStake` is a parameter applied to all subnets created, but
for `PermissionMode.Federated`, there is no collateral requirements, so
a `minStake` in the Gateway must be 0. Anything above zero will prevent
`Federated` subnet to be register in the gateway. If `minStake` is
always 0, just remove this parameter.

At the same time, `status` will be deprecated as well as collateral
alone does not manage the status of the subnet. Overall, subnets are
managing their own stake requirements and status, so that the gateway
does not really need to be aware of subnet’s status and status is not
used anywhere except for listing subnets. Subnet’s status is managed in
SubnetActor now, in bootstrapped and killed parameters, Gateway no
longer needs to maintain the status.

src/GatewayDiamond.sol

@@ -28,7 +28,6 @@ contract GatewayDiamond {
     struct ConstructorParams {
         SubnetID networkName;
         uint256 bottomUpCheckPeriod;
-        uint256 minCollateral;
         // deprecated (for now): no `msgFee` currenlty charged for cross-net messages
         uint256 msgFee;
         uint8 majorityPercentage;
@@ -37,9 +36,6 @@ contract GatewayDiamond {
     }
 
     constructor(IDiamond.FacetCut[] memory _diamondCut, ConstructorParams memory params) {
-        if (params.minCollateral == 0) {
-            revert InvalidCollateral();
-        }
         // The bottomUpCheckPeriod should be non-zero for now.
         if (params.bottomUpCheckPeriod == 0) {
             revert InvalidSubmissionPeriod();
@@ -66,7 +62,6 @@ contract GatewayDiamond {
         s.crossMsgRelayerRewards = FEATURE_CROSSMSG_RELAYER_REWARDS;
 
         s.networkName = params.networkName;
-        s.minStake = params.minCollateral;
         s.bottomUpCheckPeriod = params.bottomUpCheckPeriod;
         s.minCrossMsgFee = params.msgFee;
         s.majorityPercentage = params.majorityPercentage;

src/gateway/GatewayGetterFacet.sol

@@ -34,11 +34,6 @@ contract GatewayGetterFacet {
         return s.totalSubnets;
     }
 
-    /// @notice Returns the minimum stake required for instantiating a subnet.
-    function minStake() external view returns (uint256) {
-        return s.minStake;
-    }
-
     /// @notice Returns the maximum number of messages per bottom-up batch.
     function maxMsgsPerBottomUpBatch() external view returns (uint64) {
         return s.maxMsgsPerBottomUpBatch;

src/gateway/GatewayManagerFacet.sol

@@ -5,7 +5,6 @@ import {GatewayActorModifiers} from "../lib/LibGatewayActorStorage.sol";
 import {SubnetActorGetterFacet} from "../subnet/SubnetActorGetterFacet.sol";
 import {BURNT_FUNDS_ACTOR} from "../constants/Constants.sol";
 import {CrossMsg} from "../structs/CrossNet.sol";
-import {Status} from "../enums/Status.sol";
 import {FvmAddress} from "../structs/FvmAddress.sol";
 import {SubnetID, Subnet, SupplySource} from "../structs/Subnet.sol";
 import {Membership, SupplyKind} from "../structs/Subnet.sol";
@@ -50,7 +49,6 @@ contract GatewayManagerFacet is GatewayActorModifiers, ReentrancyGuard {
 
         subnet.id = subnetId;
         subnet.stake = collateral;
-        subnet.status = Status.Active;
         subnet.genesisEpoch = block.number;
         subnet.circSupply = genesisCircSupply;
 
@@ -72,12 +70,6 @@ contract GatewayManagerFacet is GatewayActorModifiers, ReentrancyGuard {
         }
 
         subnet.stake += msg.value;
-
-        if (subnet.status == Status.Inactive) {
-            if (subnet.stake >= s.minStake) {
-                subnet.status = Status.Active;
-            }
-        }
     }
 
     /// @notice release collateral for an existing subnet.
@@ -99,9 +91,6 @@ contract GatewayManagerFacet is GatewayActorModifiers, ReentrancyGuard {
 
         subnet.stake -= amount;
 
-        if (subnet.stake < s.minStake) {
-            subnet.status = Status.Inactive;
-        }
         payable(subnet.id.getActor()).sendValue(amount);
     }
 

src/gateway/router/BottomUpRouterFacet.sol

@@ -5,7 +5,6 @@ import {ISubnetActor} from "../../interfaces/ISubnetActor.sol";
 import {GatewayActorModifiers} from "../../lib/LibGatewayActorStorage.sol";
 import {BottomUpMsgBatch} from "../../structs/CrossNet.sol";
 import {LibGateway} from "../../lib/LibGateway.sol";
-import {Status} from "../../enums/Status.sol";
 import {BatchNotCreated, BatchAlreadyExists, InvalidBatchEpoch, NotEnoughSubnetCircSupply, SubnetNotActive, SubnetNotFound, InvalidBatchSource, MaxMsgsPerBatchExceeded, BatchWithNoMessages, InvalidCrossMsgDstSubnet, NotRegisteredSubnet, InvalidCrossMsgNonce} from "../../errors/IPCErrors.sol";
 import {Subnet} from "../../structs/Subnet.sol";
 import {LibQuorum} from "../../lib/LibQuorum.sol";
@@ -45,10 +44,6 @@ contract BottomUpRouterFacet is GatewayActorModifiers {
         if (!subnetExists) {
             revert SubnetNotFound();
         }
-        // cross-net messages can't be executed in inactive subnets.
-        if (subnet.status != Status.Active) {
-            revert SubnetNotActive();
-        }
 
         uint256 totalValue;
         uint256 totalFee;

src/gateway/router/CheckpointingFacet.sol

@@ -5,7 +5,6 @@ import {GatewayActorModifiers} from "../../lib/LibGatewayActorStorage.sol";
 import {BottomUpCheckpoint} from "../../structs/CrossNet.sol";
 import {LibGateway} from "../../lib/LibGateway.sol";
 import {LibQuorum} from "../../lib/LibQuorum.sol";
-import {Status} from "../../enums/Status.sol";
 import {Subnet} from "../../structs/Subnet.sol";
 import {QuorumObjKind} from "../../structs/Quorum.sol";
 import {Address} from "openzeppelin-contracts/utils/Address.sol";
@@ -37,10 +36,6 @@ contract CheckpointingFacet is GatewayActorModifiers {
         if (!checkpoint.subnetID.equals(subnet.id)) {
             revert InvalidSubnet();
         }
-        // only active subnets can commit checkpoints
-        if (subnet.status != Status.Active) {
-            revert SubnetNotActive();
-        }
 
         if (s.checkpointRelayerRewards) {
             // slither-disable-next-line unused-return

src/lib/LibGatewayActorStorage.sol

@@ -39,8 +39,6 @@ struct GatewayActorStorage {
     bytes32[] subnetKeys;
     /// @notice path to the current network
     SubnetID networkName;
-    /// @notice Minimum stake required to create a new subnet
-    uint256 minStake;
     /// @notice minimum fee amount charged per cross message
     uint256 minCrossMsgFee;
     /// @notice majority percentage value (must be greater than or equal to 51)

src/structs/Subnet.sol

@@ -3,7 +3,6 @@ pragma solidity 0.8.19;
 
 import {SubnetID} from "./Subnet.sol";
 import {FvmAddress} from "./FvmAddress.sol";
-import {Status} from "../enums/Status.sol";
 import {MaxPQ} from "../lib/priority/LibMaxPQ.sol";
 import {MinPQ} from "../lib/priority/LibMinPQ.sol";
 
@@ -22,7 +21,6 @@ struct Subnet {
     uint256 circSupply;
     uint64 topDownNonce;
     uint64 appliedBottomUpNonce;
-    Status status;
     SubnetID id;
 }
 

test/IntegrationTestBase.sol

@@ -7,7 +7,6 @@ import "../src/errors/IPCErrors.sol";
 
 import {EMPTY_BYTES, METHOD_SEND} from "../src/constants/Constants.sol";
 import {ConsensusType} from "../src/enums/ConsensusType.sol";
-import {Status} from "../src/enums/Status.sol";
 import {IDiamond} from "../src/interfaces/IDiamond.sol";
 import {CrossMsg, BottomUpCheckpoint, StorableMsg, ParentFinality} from "../src/structs/CrossNet.sol";
 import {FvmAddress} from "../src/structs/FvmAddress.sol";
@@ -126,7 +125,6 @@ contract TestGatewayActor is Test, TestParams {
             networkName: SubnetID({root: ROOTNET_CHAINID, route: new address[](0)}),
             bottomUpCheckPeriod: DEFAULT_CHECKPOINT_PERIOD,
             msgFee: DEFAULT_CROSS_MSG_FEE,
-            minCollateral: DEFAULT_COLLATERAL_AMOUNT,
             majorityPercentage: DEFAULT_MAJORITY_PERCENTAGE,
             genesisValidators: new Validator[](0),
             activeValidatorsLimit: DEFAULT_ACTIVE_VALIDATORS_LIMIT
@@ -653,7 +651,7 @@ contract IntegrationTestBase is Test, TestParams, TestRegistry, TestSubnetActor,
 
     function fund(address funderAddress, uint256 fundAmount, SupplyKind mode) public {
         // funding subnets is free, we do not need cross msg fee
-        (SubnetID memory subnetId, , uint256 nonceBefore, , uint256 circSupplyBefore, ) = getSubnet(address(saManager));
+        (SubnetID memory subnetId, , uint256 nonceBefore, , uint256 circSupplyBefore) = getSubnet(address(saManager));
 
         uint256 expectedTopDownMsgsLength = gwGetter.getSubnetTopDownMsgsLength(subnetId) + 1;
         uint256 expectedNonce = nonceBefore + 1;
@@ -667,7 +665,7 @@ contract IntegrationTestBase is Test, TestParams, TestRegistry, TestSubnetActor,
             gwManager.fundWithToken(subnetId, FvmAddressHelper.from(funderAddress), fundAmount);
         }
 
-        (, , uint256 nonce, , uint256 circSupply, ) = getSubnet(address(saManager));
+        (, , uint256 nonce, , uint256 circSupply) = getSubnet(address(saManager));
 
         require(gwGetter.getSubnetTopDownMsgsLength(subnetId) == expectedTopDownMsgsLength, "unexpected lengths");
 
@@ -764,12 +762,12 @@ contract IntegrationTestBase is Test, TestParams, TestRegistry, TestSubnetActor,
     function addStake(uint256 stakeAmount, address subnetAddress) public {
         uint256 balanceBefore = subnetAddress.balance;
 
-        (, uint256 stakedBefore, , , , ) = getSubnet(subnetAddress);
+        (, uint256 stakedBefore, , , ) = getSubnet(subnetAddress);
 
         gwManager.addStake{value: stakeAmount}();
 
         uint256 balanceAfter = subnetAddress.balance;
-        (, uint256 stakedAfter, , , , ) = getSubnet(subnetAddress);
+        (, uint256 stakedAfter, , , ) = getSubnet(subnetAddress);
 
         require(balanceAfter == balanceBefore - stakeAmount, "unexpected balance");
         require(stakedAfter == stakedBefore + stakeAmount, "unexpected stake");
@@ -780,7 +778,7 @@ contract IntegrationTestBase is Test, TestParams, TestRegistry, TestSubnetActor,
 
         manager.register{value: collateral}(0);
 
-        (SubnetID memory id, uint256 stake, uint256 topDownNonce, , uint256 circSupply, Status status) = getSubnetGW(
+        (SubnetID memory id, uint256 stake, uint256 topDownNonce, , uint256 circSupply) = getSubnetGW(
             subnetAddress,
             gw
         );
@@ -794,7 +792,6 @@ contract IntegrationTestBase is Test, TestParams, TestRegistry, TestSubnetActor,
         require(stake == collateral, "unexpected stake");
         require(topDownNonce == 0, "unexpected nonce");
         require(circSupply == 0, "unexpected circSupply");
-        require(status == Status.Active, "unexpected status");
     }
 
     function registerSubnet(uint256 collateral, address subnetAddress) public {
@@ -804,27 +801,18 @@ contract IntegrationTestBase is Test, TestParams, TestRegistry, TestSubnetActor,
     function getSubnetGW(
         address subnetAddress,
         GatewayDiamond gw
-    ) public returns (SubnetID memory, uint256, uint256, uint256, uint256, Status) {
+    ) public returns (SubnetID memory, uint256, uint256, uint256, uint256) {
         gwManager = GatewayManagerFacet(address(gw));
         gwGetter = GatewayGetterFacet(address(gw));
 
         SubnetID memory subnetId = gwGetter.getNetworkName().createSubnetId(subnetAddress);
 
         Subnet memory subnet = gwGetter.subnets(subnetId.toHash());
 
-        return (
-            subnet.id,
-            subnet.stake,
-            subnet.topDownNonce,
-            subnet.appliedBottomUpNonce,
-            subnet.circSupply,
-            subnet.status
-        );
+        return (subnet.id, subnet.stake, subnet.topDownNonce, subnet.appliedBottomUpNonce, subnet.circSupply);
     }
 
-    function getSubnet(
-        address subnetAddress
-    ) public returns (SubnetID memory, uint256, uint256, uint256, uint256, Status) {
+    function getSubnet(address subnetAddress) public returns (SubnetID memory, uint256, uint256, uint256, uint256) {
         return getSubnetGW(subnetAddress, gatewayDiamond);
     }
 }