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zeekayandHanzo Dev
c56386b415
P-chain stake is not natively readable from the C-chain EVM, and the obvious fix — a precompile that reads the validator set in Run() — is consensus-fatal. The BlockContext handed to Run() (precompile/contract/interfaces.go:63) carries Number, Timestamp and GetPredicateResults, and nothing else; a validator-set read from there would have to use the node's own current P-chain height (node vms/platformvm/validators/manager.go:214 getCurrentHeight -> state.GetLastAccepted), so two honest nodes executing the same block a second apart would compute different weights and fork the chain. The one place a P-chain height IS agreed is predicate verification: Block.VerifyWithContext passes ProposerVMBlockCtx.PChainHeight to VerifyPredicate (plugin/evm/block.go:283), the pass/fail bitset is written into the header (miner/worker.go:514) and re-checked on replay (plugin/evm/block.go:366). A ballot verified there is a consensus-committed fact, and historical sets stay reconstructible from P-chain weight diffs. So the ballot CLAIMS a weight and the predicate refuses any overstatement: weight <= weightAt(ballot.pChainHeight) - no flash-stake weight <= weightAt(block.pChainHeight) - no exited or shrunken validator totalWeight == totalAt(snapshot) - the denominator is exact Under-claiming is always allowed, so a voter never has to predict which block its transaction lands in. The unit of weight is the validator, and it already includes delegations: the P-chain keeps one weight per nodeID and folds each delegator into it (node vms/platformvm/state/state_validators.go:570,582 — AddStaker(own stake) then AddWeight(each delegator) under the same key). One map entry per nodeID is what makes double-counting a delegation impossible. Delegators do not get a separate ballot; their override is exit, which needs no code. Authorisation reuses the BLS key the P-chain already binds to the nodeID, so there is no registry to capture, no admin to hold it and no key ceremony. The signature covers (domain, chainID, nodeID, voter, authEpoch) only — a standing authorisation, reusable for every later proposal, rotated by signing a strictly greater epoch. Uptime is deliberately not a gate: it is absent from GetValidatorOutput and is a per-node subjective measurement (all five mainnet validators report uptime 0.0000 through the public API), so no deterministic rule can read it. Proven against a read-only fork of mainnet 96369 — the real five-validator set, real registered BLS keys, real 5e17/2.5e18 weights — including that no ballot is accepted for any of them without the operator's key. Address 0x0200...0006 is the next free slot after warp; eth_getCode on 96369 returns 0x for it and 0x01 for warp, so predicates are already live there. Co-authored-by: Hanzo Dev <[email protected]>
58 lines
1.7 KiB
Go
58 lines
1.7 KiB
Go
// Copyright (C) 2019-2025, Lux Industries, Inc. All rights reserved.
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// See the file LICENSE for licensing terms.
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package stakeweight
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import (
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"fmt"
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"github.com/luxfi/evm/precompile/contract"
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"github.com/luxfi/evm/precompile/modules"
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"github.com/luxfi/evm/precompile/precompileconfig"
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"github.com/luxfi/geth/common"
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)
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var _ contract.Configurator = (*configurator)(nil)
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// ConfigKey is the upgrade.json key that activates this precompile.
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const ConfigKey = "stakeWeightConfig"
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// ContractAddress is the next free slot in the legacy coreth-compatible
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// precompile range, immediately after warp at ...0005.
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var ContractAddress = common.HexToAddress("0x0200000000000000000000000000000000000006")
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// Module registers the precompile.
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var Module = modules.Module{
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ConfigKey: ConfigKey,
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Address: ContractAddress,
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Contract: StakeWeightPrecompile,
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Configurator: &configurator{},
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}
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type configurator struct{}
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func init() {
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if err := modules.RegisterModule(Module); err != nil {
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panic(err)
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}
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}
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// MakeConfig returns an empty config for Marshal/Unmarshal.
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func (*configurator) MakeConfig() precompileconfig.Config { return new(Config) }
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// MakeGenesisConfig returns a config activated at genesis.
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func (*configurator) MakeGenesisConfig() precompileconfig.Config {
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var zero uint64
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return NewConfig(&zero)
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}
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// Configure stores nothing: the precompile holds no state and no privileged
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// address, so there is nothing to seed and nobody to seed it for.
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func (*configurator) Configure(_ precompileconfig.ChainConfig, cfg precompileconfig.Config, _ contract.StateDB, _ contract.ConfigurationBlockContext) error {
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if _, ok := cfg.(*Config); !ok {
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return fmt.Errorf("expected config type %T, got %T: %v", &Config{}, cfg, cfg)
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}
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return nil
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}
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