refactor: Revert middlewares to antehandler (part 2/2: posthandler)

CHANGELOG.md

@@ -39,6 +39,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Features
 
+* (types) [#11985](https://github.com/cosmos/cosmos-sdk/pull/11985) Add a `Priority` field on `sdk.Context`, which represents the CheckTx priority field. It is only used during CheckTx.
 * (gRPC) [#11889](https://github.com/cosmos/cosmos-sdk/pull/11889) Support custom read and write gRPC options in `app.toml`. See `max-recv-msg-size` and `max-send-msg-size` respectively.
 * (cli) [\#11738](https://github.com/cosmos/cosmos-sdk/pull/11738) Add `tx auth multi-sign` as alias of `tx auth multisign` for consistency with `multi-send`.
 * (cli) [\#11738](https://github.com/cosmos/cosmos-sdk/pull/11738) Add `tx bank multi-send` command for bulk send of coins to multiple accounts.
@@ -90,6 +91,8 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### API Breaking Changes
 
+* (x/auth/ante) [#11985](https://github.com/cosmos/cosmos-sdk/pull/11985) The `MempoolFeeDecorator` has been removed. Instead, the `DeductFeeDecorator` takes a new argument of type `TxFeeChecker`, to define custom fee models. If `nil` is passed to this `TxFeeChecker` argument, then it will default to `checkTxFeeWithValidatorMinGasPrices`, which is the exact same behavior as the old `MempoolFeeDecorator` (i.e. checking fees against validator's own min gas price).
+* (x/auth/ante) [#11985](https://github.com/cosmos/cosmos-sdk/pull/11985) The `ExtensionOptionsDecorator` takes an argument of type `ExtensionOptionChecker`. For backwards-compatibility, you can pass `nil`, which defaults to the old behavior of rejecting all tx extensions.
 * (crypto/keyring) [#11932](https://github.com/cosmos/cosmos-sdk/pull/11932) Remove `Unsafe*` interfaces from keyring package. Please use interface casting if you wish to access those unsafe functions.
 * (types) [#11881](https://github.com/cosmos/cosmos-sdk/issues/11881) Rename `AccAddressFromHex` to `AccAddressFromHexUnsafe`.
 * (types) [#11788](https://github.com/cosmos/cosmos-sdk/pull/11788) The `Int` and `Uint` types have been moved to their own dedicated module, `math`. Aliases are kept in the SDK's root `types` package, however, it is encouraged to utilize the new `math` module. As a result, the `Int#ToDec` API has been removed.
@@ -277,6 +280,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### State Machine Breaking
 
+* (baseapp) [\#11985](https://github.com/cosmos/cosmos-sdk/pull/11985) Add a `postHandler` to baseapp. This `postHandler` is like antehandler, but is run _after_ the `runMsgs` execution. It is in the same store branch that `runMsgs`, meaning that both `runMsgs` and `postHandler`
 * (x/gov) [#11998](https://github.com/cosmos/cosmos-sdk/pull/11998) Tweak the `x/gov` `ModuleAccountInvariant` invariant to ensure deposits are `<=` total module account balance instead of strictly equal.
 * (x/upgrade) [\#11800](https://github.com/cosmos/cosmos-sdk/pull/11800) Fix `GetLastCompleteUpgrade` to properly return the latest upgrade.
 * [\#10564](https://github.com/cosmos/cosmos-sdk/pull/10564) Fix bug when updating allowance inside AllowedMsgAllowance

baseapp/baseapp.go

@@ -58,6 +58,7 @@ type BaseApp struct { // nolint: maligned
 	txDecoder         sdk.TxDecoder // unmarshal []byte into sdk.Tx
 
 	anteHandler    sdk.AnteHandler  // ante handler for fee and auth
+	postHandler    sdk.AnteHandler  // post handler, optional, e.g. for tips
 	initChainer    sdk.InitChainer  // initialize state with validators and state blob
 	beginBlocker   sdk.BeginBlocker // logic to run before any txs
 	endBlocker     sdk.EndBlocker   // logic to run after all txs, and to determine valset changes
@@ -688,6 +689,17 @@ func (app *BaseApp) runTx(mode runTxMode, txBytes []byte) (gInfo sdk.GasInfo, re
 	// Result if any single message fails or does not have a registered Handler.
 	result, err = app.runMsgs(runMsgCtx, msgs, mode)
 	if err == nil && mode == runTxModeDeliver {
+		// Run optional postHandlers
+		if app.postHandler != nil {
+			newCtx, err := app.postHandler(runMsgCtx, tx, mode == runTxModeSimulate)
+
+			if err != nil {
+				return gInfo, nil, nil, err
+			}
+
+			result.Events = append(result.Events, newCtx.EventManager().ABCIEvents()...)
+		}
+
 		// When block gas exceeds, it'll panic and won't commit the cached store.
 		consumeBlockGas()
 

baseapp/options.go

@@ -153,6 +153,14 @@ func (app *BaseApp) SetAnteHandler(ah sdk.AnteHandler) {
 	app.anteHandler = ah
 }
 
+func (app *BaseApp) SetPostHandler(ph sdk.AnteHandler) {
+	if app.sealed {
+		panic("SetPostHandler() on sealed BaseApp")
+	}
+
+	app.postHandler = ph
+}
+
 func (app *BaseApp) SetAddrPeerFilter(pf sdk.PeerFilter) {
 	if app.sealed {
 		panic("SetAddrPeerFilter() on sealed BaseApp")

simapp/app.go

@@ -34,6 +34,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/auth"
 	"github.com/cosmos/cosmos-sdk/x/auth/ante"
 	authkeeper "github.com/cosmos/cosmos-sdk/x/auth/keeper"
+	"github.com/cosmos/cosmos-sdk/x/auth/posthandler"
 	authsims "github.com/cosmos/cosmos-sdk/x/auth/simulation"
 	authtx "github.com/cosmos/cosmos-sdk/x/auth/tx"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
@@ -443,6 +444,24 @@ func NewSimApp(
 	app.SetBeginBlocker(app.BeginBlocker)
 	app.SetEndBlocker(app.EndBlocker)
 	app.setAnteHandler(encodingConfig.TxConfig, cast.ToStringSlice(appOpts.Get(server.FlagIndexEvents)))
+	// In v0.46, the SDK introduces _postHandlers_. PostHandlers are like
+	// antehandlers, but are run _after_ the `runMsgs` execution. They are also
+	// defined as a chain, and have the same signature as antehandlers.
+	//
+	// In baseapp, postHandlers are run in the same store branch as `runMsgs`,
+	// meaning that both `runMsgs` and `postHandler` state will be committed if
+	// both are successful, and both will be reverted if any of the two fails.
+	//
+	// The SDK exposes a default postHandlers chain, which comprises of only
+	// one decorator: the Transaction Tips decorator. However, some chains do
+	// not need it by default, so the following line is commented out. You can
+	// uncomment it to include the tips decorator, or define your own
+	// postHandler chain. Please note that changing any of the anteHandler or
+	// postHandler chain is likely to be a state-machine breaking change, which
+	// needs a coordinated upgrade.
+	//
+	// Uncomment to enable postHandlers:
+	// app.setPostHandler()
 
 	if loadLatest {
 		if err := app.LoadLatestVersion(); err != nil {
@@ -475,6 +494,19 @@ func (app *SimApp) setAnteHandler(txConfig client.TxConfig, indexEventsStr []str
 	app.SetAnteHandler(anteHandler)
 }
 
+func (app *SimApp) setPostHandler() {
+	postHandler, err := posthandler.NewPostHandler(
+		posthandler.HandlerOptions{
+			BankKeeper: app.BankKeeper,
+		},
+	)
+	if err != nil {
+		panic(err)
+	}
+
+	app.SetPostHandler(postHandler)
+}
+
 // Name returns the name of the App
 func (app *SimApp) Name() string { return app.BaseApp.Name() }
 

types/context.go

@@ -38,6 +38,7 @@ type Context struct {
 	minGasPrice   DecCoins
 	consParams    *tmproto.ConsensusParams
 	eventManager  *EventManager
+	priority      int64 // The tx priority, only relevant in CheckTx
 }
 
 // Proposed rename, not done to avoid API breakage
@@ -58,6 +59,7 @@ func (c Context) IsCheckTx() bool             { return c.checkTx }
 func (c Context) IsReCheckTx() bool           { return c.recheckTx }
 func (c Context) MinGasPrices() DecCoins      { return c.minGasPrice }
 func (c Context) EventManager() *EventManager { return c.eventManager }
+func (c Context) Priority() int64             { return c.priority }
 
 // clone the header before returning
 func (c Context) BlockHeader() tmproto.Header {
@@ -226,6 +228,12 @@ func (c Context) WithEventManager(em *EventManager) Context {
 	return c
 }
 
+// WithEventManager returns a Context with an updated tx priority
+func (c Context) WithPriority(p int64) Context {
+	c.priority = p
+	return c
+}
+
 // TODO: remove???
 func (c Context) IsZero() bool {
 	return c.ms == nil

x/auth/ante/ante.go

@@ -10,11 +10,13 @@ import (
 
 // HandlerOptions are the options required for constructing a default SDK AnteHandler.
 type HandlerOptions struct {
-	AccountKeeper   AccountKeeper
-	BankKeeper      types.BankKeeper
-	FeegrantKeeper  FeegrantKeeper
-	SignModeHandler authsigning.SignModeHandler
-	SigGasConsumer  func(meter sdk.GasMeter, sig signing.SignatureV2, params types.Params) error
+	AccountKeeper          AccountKeeper
+	BankKeeper             types.BankKeeper
+	ExtensionOptionChecker ExtensionOptionChecker
+	FeegrantKeeper         FeegrantKeeper
+	SignModeHandler        authsigning.SignModeHandler
+	SigGasConsumer         func(meter sdk.GasMeter, sig signing.SignatureV2, params types.Params) error
+	TxFeeChecker           TxFeeChecker
 }
 
 // NewAnteHandler returns an AnteHandler that checks and increments sequence
@@ -33,23 +35,17 @@ func NewAnteHandler(options HandlerOptions) (sdk.AnteHandler, error) {
 		return nil, sdkerrors.Wrap(sdkerrors.ErrLogic, "sign mode handler is required for ante builder")
 	}
 
-	var sigGasConsumer = options.SigGasConsumer
-	if sigGasConsumer == nil {
-		sigGasConsumer = DefaultSigVerificationGasConsumer
-	}
-
 	anteDecorators := []sdk.AnteDecorator{
 		NewSetUpContextDecorator(), // outermost AnteDecorator. SetUpContext must be called first
-		NewRejectExtensionOptionsDecorator(),
-		NewMempoolFeeDecorator(),
+		NewExtensionOptionsDecorator(options.ExtensionOptionChecker),
 		NewValidateBasicDecorator(),
 		NewTxTimeoutHeightDecorator(),
 		NewValidateMemoDecorator(options.AccountKeeper),
 		NewConsumeGasForTxSizeDecorator(options.AccountKeeper),
-		NewDeductFeeDecorator(options.AccountKeeper, options.BankKeeper, options.FeegrantKeeper),
+		NewDeductFeeDecorator(options.AccountKeeper, options.BankKeeper, options.FeegrantKeeper, options.TxFeeChecker),
 		NewSetPubKeyDecorator(options.AccountKeeper), // SetPubKeyDecorator must be called before all signature verification decorators
 		NewValidateSigCountDecorator(options.AccountKeeper),
-		NewSigGasConsumeDecorator(options.AccountKeeper, sigGasConsumer),
+		NewSigGasConsumeDecorator(options.AccountKeeper, options.SigGasConsumer),
 		NewSigVerificationDecorator(options.AccountKeeper, options.SignModeHandler),
 		NewIncrementSequenceDecorator(options.AccountKeeper),
 	}

x/auth/ante/ext.go

@@ -2,7 +2,7 @@ package ante
 
 import (
 	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
-	"github.com/cosmos/cosmos-sdk/types"
+	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 )
 
@@ -11,26 +11,55 @@ type HasExtensionOptionsTx interface {
 	GetNonCriticalExtensionOptions() []*codectypes.Any
 }
 
+// ExtensionOptionChecker is a function that returns true if the extension option is accepted.
+type ExtensionOptionChecker func(*codectypes.Any) bool
+
+// rejectExtensionOption is the default extension check that reject all tx
+// extensions.
+func rejectExtensionOption(*codectypes.Any) bool {
+	return false
+}
+
 // RejectExtensionOptionsDecorator is an AnteDecorator that rejects all extension
 // options which can optionally be included in protobuf transactions. Users that
 // need extension options should create a custom AnteHandler chain that handles
 // needed extension options properly and rejects unknown ones.
-type RejectExtensionOptionsDecorator struct{}
+type RejectExtensionOptionsDecorator struct {
+	checker ExtensionOptionChecker
+}
+
+// NewExtensionOptionsDecorator creates a new antehandler that rejects all extension
+// options which can optionally be included in protobuf transactions that don't pass the checker.
+// Users that need extension options should pass a custom checker that returns true for the
+// needed extension options.
+func NewExtensionOptionsDecorator(checker ExtensionOptionChecker) sdk.AnteDecorator {
+	if checker == nil {
+		checker = rejectExtensionOption
+	}
 
-// NewRejectExtensionOptionsDecorator creates a new RejectExtensionOptionsDecorator
-func NewRejectExtensionOptionsDecorator() RejectExtensionOptionsDecorator {
-	return RejectExtensionOptionsDecorator{}
+	return RejectExtensionOptionsDecorator{checker: checker}
 }
 
-var _ types.AnteDecorator = RejectExtensionOptionsDecorator{}
+var _ sdk.AnteDecorator = RejectExtensionOptionsDecorator{}
 
 // AnteHandle implements the AnteDecorator.AnteHandle method
-func (r RejectExtensionOptionsDecorator) AnteHandle(ctx types.Context, tx types.Tx, simulate bool, next types.AnteHandler) (newCtx types.Context, err error) {
+func (r RejectExtensionOptionsDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
+	err = checkExtOpts(tx, r.checker)
+	if err != nil {
+		return ctx, err
+	}
+
+	return next(ctx, tx, simulate)
+}
+
+func checkExtOpts(tx sdk.Tx, checker ExtensionOptionChecker) error {
 	if hasExtOptsTx, ok := tx.(HasExtensionOptionsTx); ok {
-		if len(hasExtOptsTx.GetExtensionOptions()) != 0 {
-			return ctx, sdkerrors.ErrUnknownExtensionOptions
+		for _, opt := range hasExtOptsTx.GetExtensionOptions() {
+			if !checker(opt) {
+				return sdkerrors.ErrUnknownExtensionOptions
+			}
 		}
 	}
 
-	return next(ctx, tx, simulate)
+	return nil
 }

x/auth/ante/ext_test.go

@@ -1,7 +1,7 @@
 package ante_test
 
 import (
-	"github.com/cosmos/cosmos-sdk/codec/types"
+	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
 	"github.com/cosmos/cosmos-sdk/testutil/testdata"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/x/auth/ante"
@@ -10,27 +10,45 @@ import (
 
 func (suite *AnteTestSuite) TestRejectExtensionOptionsDecorator() {
 	suite.SetupTest(true) // setup
-	suite.txBuilder = suite.clientCtx.TxConfig.NewTxBuilder()
 
-	reod := ante.NewRejectExtensionOptionsDecorator()
-	antehandler := sdk.ChainAnteDecorators(reod)
+	testCases := []struct {
+		msg   string
+		allow bool
+	}{
+		{"allow extension", true},
+		{"reject extension", false},
+	}
+	for _, tc := range testCases {
+		suite.Run(tc.msg, func() {
+			txBuilder := suite.clientCtx.TxConfig.NewTxBuilder()
 
-	// no extension options should not trigger an error
-	theTx := suite.txBuilder.GetTx()
-	_, err := antehandler(suite.ctx, theTx, false)
-	suite.Require().NoError(err)
+			reod := ante.NewExtensionOptionsDecorator(func(_ *codectypes.Any) bool {
+				return tc.allow
+			})
+			antehandler := sdk.ChainAnteDecorators(reod)
 
-	extOptsTxBldr, ok := suite.txBuilder.(tx.ExtensionOptionsTxBuilder)
-	if !ok {
-		// if we can't set extension options, this decorator doesn't apply and we're done
-		return
-	}
+			// no extension options should not trigger an error
+			theTx := txBuilder.GetTx()
+			_, err := antehandler(suite.ctx, theTx, false)
+			suite.Require().NoError(err)
 
-	// setting any extension option should cause an error
-	any, err := types.NewAnyWithValue(testdata.NewTestMsg())
-	suite.Require().NoError(err)
-	extOptsTxBldr.SetExtensionOptions(any)
-	theTx = suite.txBuilder.GetTx()
-	_, err = antehandler(suite.ctx, theTx, false)
-	suite.Require().EqualError(err, "unknown extension options")
+			extOptsTxBldr, ok := txBuilder.(tx.ExtensionOptionsTxBuilder)
+			if !ok {
+				// if we can't set extension options, this decorator doesn't apply and we're done
+				return
+			}
+
+			// set an extension option and check
+			any, err := codectypes.NewAnyWithValue(testdata.NewTestMsg())
+			suite.Require().NoError(err)
+			extOptsTxBldr.SetExtensionOptions(any)
+			theTx = txBuilder.GetTx()
+			_, err = antehandler(suite.ctx, theTx, false)
+			if tc.allow {
+				suite.Require().NoError(err)
+			} else {
+				suite.Require().EqualError(err, "unknown extension options")
+			}
+		})
+	}
 }