Merge PR #2122: Implement slashing period

* Update PENDING.md

* SlashingPeriod struct

* Seperate keys.go, constant prefixes

* Make linter happy

* Update Gopkg.lock

* Seek slashing period by infraction height

* Slashing period hooks

* Slashing period unit tests; bugfix

* Add simple hook tests

* Add sdk.ValidatorHooks interface

* No-op hooks

* Real hooks

* Fix iteration direction & duplicate key, update Gaia

* Correctly simulate past validator set signatures

* Tiny rename

* Update dep; 'make format'

* Add quick slashing period functionality test

* Additional unit tests

* Use current validators when selected

* Panic in the right place

* Address @rigelrozanski comments

* Fix linter errors

* Address @melekes suggestion

* Rename hook

* Update for new bech32 types

* 'make format'

PENDING.md

@@ -30,6 +30,7 @@ BREAKING CHANGES
 * SDK
     * [core] \#1807 Switch from use of rational to decimal
     * [types] \#1901 Validator interface's GetOwner() renamed to GetOperator()
+    * [x/slashing] [#2122](https://github.com/cosmos/cosmos-sdk/pull/2122) - Implement slashing period
     * [types] \#2119 Parsed error messages and ABCI log errors to make them more human readable.
     * [simulation] Rename TestAndRunTx to Operation [#2153](https://github.com/cosmos/cosmos-sdk/pull/2153)
 

cmd/gaia/app/app.go

@@ -93,9 +93,10 @@ func NewGaiaApp(logger log.Logger, db dbm.DB, traceStore io.Writer, baseAppOptio
 	app.ibcMapper = ibc.NewMapper(app.cdc, app.keyIBC, app.RegisterCodespace(ibc.DefaultCodespace))
 	app.paramsKeeper = params.NewKeeper(app.cdc, app.keyParams)
 	app.stakeKeeper = stake.NewKeeper(app.cdc, app.keyStake, app.coinKeeper, app.RegisterCodespace(stake.DefaultCodespace))
+	app.slashingKeeper = slashing.NewKeeper(app.cdc, app.keySlashing, app.stakeKeeper, app.paramsKeeper.Getter(), app.RegisterCodespace(slashing.DefaultCodespace))
+	app.stakeKeeper = app.stakeKeeper.WithValidatorHooks(app.slashingKeeper.ValidatorHooks())
 	app.govKeeper = gov.NewKeeper(app.cdc, app.keyGov, app.paramsKeeper.Setter(), app.coinKeeper, app.stakeKeeper, app.RegisterCodespace(gov.DefaultCodespace))
 	app.feeCollectionKeeper = auth.NewFeeCollectionKeeper(app.cdc, app.keyFeeCollection)
-	app.slashingKeeper = slashing.NewKeeper(app.cdc, app.keySlashing, app.stakeKeeper, app.paramsKeeper.Getter(), app.RegisterCodespace(slashing.DefaultCodespace))
 
 	// register message routes
 	app.Router().

server/tm_cmds.go

@@ -7,11 +7,11 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
+	"github.com/cosmos/cosmos-sdk/client"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	tcmd "github.com/tendermint/tendermint/cmd/tendermint/commands"
 	"github.com/tendermint/tendermint/p2p"
 	pvm "github.com/tendermint/tendermint/privval"
-	"github.com/cosmos/cosmos-sdk/client"
 )
 
 // ShowNodeIDCmd - ported from Tendermint, dump node ID to stdout

types/decimal.go

@@ -415,6 +415,14 @@ func MinDec(d1, d2 Dec) Dec {
 	return d2
 }
 
+// maximum decimal between two
+func MaxDec(d1, d2 Dec) Dec {
+	if d1.LT(d2) {
+		return d2
+	}
+	return d1
+}
+
 // intended to be used with require/assert:  require.True(DecEq(...))
 func DecEq(t *testing.T, exp, got Dec) (*testing.T, bool, string, Dec, Dec) {
 	return t, exp.Equal(got), "expected:\t%v\ngot:\t\t%v", exp, got

types/stake.go

@@ -99,3 +99,13 @@ type DelegationSet interface {
 	IterateDelegations(ctx Context, delegator AccAddress,
 		fn func(index int64, delegation Delegation) (stop bool))
 }
+
+// validator event hooks
+// These can be utilized to communicate between a staking keeper
+// and another keeper which must take particular actions when
+// validators are bonded and unbonded. The second keeper must implement
+// this interface, which then the staking keeper can call.
+type ValidatorHooks interface {
+	OnValidatorBonded(ctx Context, address ConsAddress)         // Must be called when a validator is bonded
+	OnValidatorBeginUnbonding(ctx Context, address ConsAddress) // Must be called when a validator begins unbonding
+}

x/mock/simulation/random_simulate_blocks.go

@@ -67,16 +67,18 @@ func SimulateFromSeed(
 	header := abci.Header{Height: 0, Time: timestamp}
 	opCount := 0
 
-	request := abci.RequestBeginBlock{Header: header}
-
 	var pastTimes []time.Time
+	var pastSigningValidators [][]abci.SigningValidator
+
+	request := RandomRequestBeginBlock(t, r, validators, livenessTransitionMatrix, evidenceFraction, pastTimes, pastSigningValidators, event, header, log)
 	// These are operations which have been queued by previous operations
 	operationQueue := make(map[int][]Operation)
 
 	for i := 0; i < numBlocks; i++ {
 
 		// Log the header time for future lookup
 		pastTimes = append(pastTimes, header.Time)
+		pastSigningValidators = append(pastSigningValidators, request.LastCommitInfo.Validators)
 
 		// Run the BeginBlock handler
 		app.BeginBlock(request)
@@ -131,7 +133,7 @@ func SimulateFromSeed(
 		}
 
 		// Generate a random RequestBeginBlock with the current validator set for the next block
-		request = RandomRequestBeginBlock(t, r, validators, livenessTransitionMatrix, evidenceFraction, pastTimes, event, header, log)
+		request = RandomRequestBeginBlock(t, r, validators, livenessTransitionMatrix, evidenceFraction, pastTimes, pastSigningValidators, event, header, log)
 
 		// Update the validator set
 		validators = updateValidators(t, r, validators, res.ValidatorUpdates, event)
@@ -187,13 +189,12 @@ func getKeys(validators map[string]mockValidator) []string {
 
 // RandomRequestBeginBlock generates a list of signing validators according to the provided list of validators, signing fraction, and evidence fraction
 func RandomRequestBeginBlock(t *testing.T, r *rand.Rand, validators map[string]mockValidator, livenessTransitions TransitionMatrix, evidenceFraction float64,
-	pastTimes []time.Time, event func(string), header abci.Header, log string) abci.RequestBeginBlock {
+	pastTimes []time.Time, pastSigningValidators [][]abci.SigningValidator, event func(string), header abci.Header, log string) abci.RequestBeginBlock {
 	if len(validators) == 0 {
 		return abci.RequestBeginBlock{Header: header}
 	}
 	signingValidators := make([]abci.SigningValidator, len(validators))
 	i := 0
-
 	for _, key := range getKeys(validators) {
 		mVal := validators[key]
 		mVal.livenessState = livenessTransitions.NextState(r, mVal.livenessState)
@@ -220,26 +221,31 @@ func RandomRequestBeginBlock(t *testing.T, r *rand.Rand, validators map[string]m
 		i++
 	}
 	evidence := make([]abci.Evidence, 0)
-	for r.Float64() < evidenceFraction {
-		height := header.Height
-		time := header.Time
-		if r.Float64() < pastEvidenceFraction {
-			height = int64(r.Intn(int(header.Height)))
-			time = pastTimes[height]
-		}
-		validator := signingValidators[r.Intn(len(signingValidators))].Validator
-		var currentTotalVotingPower int64
-		for _, mVal := range validators {
-			currentTotalVotingPower += mVal.val.Power
+	// Anything but the first block
+	if len(pastTimes) > 0 {
+		for r.Float64() < evidenceFraction {
+			height := header.Height
+			time := header.Time
+			vals := signingValidators
+			if r.Float64() < pastEvidenceFraction {
+				height = int64(r.Intn(int(header.Height)))
+				time = pastTimes[height]
+				vals = pastSigningValidators[height]
+			}
+			validator := vals[r.Intn(len(vals))].Validator
+			var totalVotingPower int64
+			for _, val := range vals {
+				totalVotingPower += val.Validator.Power
+			}
+			evidence = append(evidence, abci.Evidence{
+				Type:             tmtypes.ABCIEvidenceTypeDuplicateVote,
+				Validator:        validator,
+				Height:           height,
+				Time:             time,
+				TotalVotingPower: totalVotingPower,
+			})
+			event("beginblock/evidence")
 		}
-		evidence = append(evidence, abci.Evidence{
-			Type:             tmtypes.ABCIEvidenceTypeDuplicateVote,
-			Validator:        validator,
-			Height:           height,
-			Time:             time,
-			TotalVotingPower: currentTotalVotingPower,
-		})
-		event("beginblock/evidence")
 	}
 	return abci.RequestBeginBlock{
 		Header: header,

x/slashing/app_test.go

@@ -79,7 +79,7 @@ func checkValidator(t *testing.T, mapp *mock.App, keeper stake.Keeper,
 }
 
 func checkValidatorSigningInfo(t *testing.T, mapp *mock.App, keeper Keeper,
-	addr sdk.ValAddress, expFound bool) ValidatorSigningInfo {
+	addr sdk.ConsAddress, expFound bool) ValidatorSigningInfo {
 	ctxCheck := mapp.BaseApp.NewContext(true, abci.Header{})
 	signingInfo, found := keeper.getValidatorSigningInfo(ctxCheck, addr)
 	require.Equal(t, expFound, found)
@@ -113,7 +113,7 @@ func TestSlashingMsgs(t *testing.T) {
 	unjailMsg := MsgUnjail{ValidatorAddr: sdk.ValAddress(validator.PubKey.Address())}
 
 	// no signing info yet
-	checkValidatorSigningInfo(t, mapp, keeper, sdk.ValAddress(addr1), false)
+	checkValidatorSigningInfo(t, mapp, keeper, sdk.ConsAddress(addr1), false)
 
 	// unjail should fail with unknown validator
 	res := mock.SignCheckDeliver(t, mapp.BaseApp, []sdk.Msg{unjailMsg}, []int64{0}, []int64{1}, false, false, priv1)

x/slashing/client/cli/query.go

@@ -25,7 +25,7 @@ func GetCmdQuerySigningInfo(storeName string, cdc *wire.Codec) *cobra.Command {
 				return err
 			}
 
-			key := slashing.GetValidatorSigningInfoKey(sdk.ValAddress(pk.Address()))
+			key := slashing.GetValidatorSigningInfoKey(sdk.ConsAddress(pk.Address()))
 			cliCtx := context.NewCLIContext().WithCodec(cdc)
 
 			res, err := cliCtx.QueryStore(key, storeName)

x/slashing/client/rest/query.go

@@ -30,7 +30,7 @@ func signingInfoHandlerFn(cliCtx context.CLIContext, storeName string, cdc *wire
 			return
 		}
 
-		key := slashing.GetValidatorSigningInfoKey(sdk.ValAddress(pk.Address()))
+		key := slashing.GetValidatorSigningInfoKey(sdk.ConsAddress(pk.Address()))
 
 		res, err := cliCtx.QueryStore(key, storeName)
 		if err != nil {

x/slashing/handler.go

@@ -34,7 +34,7 @@ func handleMsgUnjail(ctx sdk.Context, msg MsgUnjail, k Keeper) sdk.Result {
 		return ErrValidatorNotJailed(k.codespace).Result()
 	}
 
-	addr := sdk.ValAddress(validator.GetPubKey().Address())
+	addr := sdk.ConsAddress(validator.GetPubKey().Address())
 
 	info, found := k.getValidatorSigningInfo(ctx, addr)
 	if !found {

x/slashing/handler_test.go

@@ -20,7 +20,7 @@ func TestCannotUnjailUnlessJailed(t *testing.T) {
 	got := stake.NewHandler(sk)(ctx, msg)
 	require.True(t, got.IsOK())
 	stake.EndBlocker(ctx, sk)
-	require.Equal(t, ck.GetCoins(ctx, addr), sdk.Coins{{sk.GetParams(ctx).BondDenom, initCoins.Sub(amt)}})
+	require.Equal(t, ck.GetCoins(ctx, sdk.AccAddress(addr)), sdk.Coins{{sk.GetParams(ctx).BondDenom, initCoins.Sub(amt)}})
 	require.True(t, sdk.NewDecFromInt(amt).Equal(sk.Validator(ctx, sdk.ValAddress(addr)).GetPower()))
 
 	// assert non-jailed validator can't be unjailed

x/slashing/hooks.go

@@ -0,0 +1,46 @@
+package slashing
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+// Create a new slashing period when a validator is bonded
+func (k Keeper) onValidatorBonded(ctx sdk.Context, address sdk.ConsAddress) {
+	slashingPeriod := ValidatorSlashingPeriod{
+		ValidatorAddr: address,
+		StartHeight:   ctx.BlockHeight(),
+		EndHeight:     0,
+		SlashedSoFar:  sdk.ZeroDec(),
+	}
+	k.addOrUpdateValidatorSlashingPeriod(ctx, slashingPeriod)
+}
+
+// Mark the slashing period as having ended when a validator begins unbonding
+func (k Keeper) onValidatorBeginUnbonding(ctx sdk.Context, address sdk.ConsAddress) {
+	slashingPeriod := k.getValidatorSlashingPeriodForHeight(ctx, address, ctx.BlockHeight())
+	slashingPeriod.EndHeight = ctx.BlockHeight()
+	k.addOrUpdateValidatorSlashingPeriod(ctx, slashingPeriod)
+}
+
+// Wrapper struct for sdk.ValidatorHooks
+type ValidatorHooks struct {
+	k Keeper
+}
+
+// Assert implementation
+var _ sdk.ValidatorHooks = ValidatorHooks{}
+
+// Return a sdk.ValidatorHooks interface over the wrapper struct
+func (k Keeper) ValidatorHooks() sdk.ValidatorHooks {
+	return ValidatorHooks{k}
+}
+
+// Implements sdk.ValidatorHooks
+func (v ValidatorHooks) OnValidatorBonded(ctx sdk.Context, address sdk.ConsAddress) {
+	v.k.onValidatorBonded(ctx, address)
+}
+
+// Implements sdk.ValidatorHooks
+func (v ValidatorHooks) OnValidatorBeginUnbonding(ctx sdk.Context, address sdk.ConsAddress) {
+	v.k.onValidatorBeginUnbonding(ctx, address)
+}

x/slashing/hooks_test.go

@@ -0,0 +1,26 @@
+package slashing
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+func TestHookOnValidatorBonded(t *testing.T) {
+	ctx, _, _, _, keeper := createTestInput(t)
+	addr := sdk.ConsAddress(addrs[0])
+	keeper.onValidatorBonded(ctx, addr)
+	period := keeper.getValidatorSlashingPeriodForHeight(ctx, addr, ctx.BlockHeight())
+	require.Equal(t, ValidatorSlashingPeriod{addr, ctx.BlockHeight(), 0, sdk.ZeroDec()}, period)
+}
+
+func TestHookOnValidatorBeginUnbonding(t *testing.T) {
+	ctx, _, _, _, keeper := createTestInput(t)
+	addr := sdk.ConsAddress(addrs[0])
+	keeper.onValidatorBonded(ctx, addr)
+	keeper.onValidatorBeginUnbonding(ctx, addr)
+	period := keeper.getValidatorSlashingPeriodForHeight(ctx, addr, ctx.BlockHeight())
+	require.Equal(t, ValidatorSlashingPeriod{addr, ctx.BlockHeight(), ctx.BlockHeight(), sdk.ZeroDec()}, period)
+}

x/slashing/keeper.go

@@ -40,7 +40,7 @@ func (k Keeper) handleDoubleSign(ctx sdk.Context, addr crypto.Address, infractio
 	logger := ctx.Logger().With("module", "x/slashing")
 	time := ctx.BlockHeader().Time
 	age := time.Sub(timestamp)
-	address := sdk.ValAddress(addr)
+	address := sdk.ConsAddress(addr)
 	pubkey, err := k.getPubkey(ctx, addr)
 	if err != nil {
 		panic(fmt.Sprintf("Validator address %v not found", addr))
@@ -56,8 +56,14 @@ func (k Keeper) handleDoubleSign(ctx sdk.Context, addr crypto.Address, infractio
 	// Double sign confirmed
 	logger.Info(fmt.Sprintf("Confirmed double sign from %s at height %d, age of %d less than max age of %d", pubkey.Address(), infractionHeight, age, maxEvidenceAge))
 
+	// Cap the amount slashed to the penalty for the worst infraction
+	// within the slashing period when this infraction was committed
+	fraction := k.SlashFractionDoubleSign(ctx)
+	revisedFraction := k.capBySlashingPeriod(ctx, address, fraction, infractionHeight)
+	logger.Info(fmt.Sprintf("Fraction slashed capped by slashing period from %v to %v", fraction, revisedFraction))
+
 	// Slash validator
-	k.validatorSet.Slash(ctx, pubkey, infractionHeight, power, k.SlashFractionDoubleSign(ctx))
+	k.validatorSet.Slash(ctx, pubkey, infractionHeight, power, revisedFraction)
 
 	// Jail validator
 	k.validatorSet.Jail(ctx, pubkey)
@@ -76,7 +82,7 @@ func (k Keeper) handleDoubleSign(ctx sdk.Context, addr crypto.Address, infractio
 func (k Keeper) handleValidatorSignature(ctx sdk.Context, addr crypto.Address, power int64, signed bool) {
 	logger := ctx.Logger().With("module", "x/slashing")
 	height := ctx.BlockHeight()
-	address := sdk.ValAddress(addr)
+	address := sdk.ConsAddress(addr)
 	pubkey, err := k.getPubkey(ctx, addr)
 	if err != nil {
 		panic(fmt.Sprintf("Validator address %v not found", addr))
@@ -169,7 +175,3 @@ func (k Keeper) deleteAddrPubkeyRelation(ctx sdk.Context, addr crypto.Address) {
 	store := ctx.KVStore(k.storeKey)
 	store.Delete(getAddrPubkeyRelationKey(addr))
 }
-
-func getAddrPubkeyRelationKey(address []byte) []byte {
-	return append([]byte{0x03}, address...)
-}