cmd: step command

cmd/gen_proof.go

-package cmd
-
-import "github.com/urfave/cli/v2"
-
-func GenProof(ctx *cli.Context) error {
-	// TODO
-	return nil
-}
-
-var GenProofCommand = &cli.Command{
-	Name:        "gen-proof",
-	Usage:       "",
-	Description: "",
-	Action:      GenProof,
-	Flags:       nil,
-}

cmd/json.go

+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+)
+
+func loadJSON[X any](inputPath string) (*X, error) {
+	f, err := os.OpenFile(inputPath, os.O_RDONLY, 0)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open file %q: %w", inputPath, err)
+	}
+	defer f.Close()
+	var state X
+	if err := json.NewDecoder(f).Decode(&state); err != nil {
+		return nil, fmt.Errorf("failed to decode file %q: %w", inputPath, err)
+	}
+	return &state, nil
+}
+
+func writeJSON[X any](outputPath string, value X, outIfEmpty bool) error {
+	var out io.Writer
+	if outputPath != "" {
+		f, err := os.OpenFile(outputPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0755)
+		if err != nil {
+			return fmt.Errorf("failed to open output file: %w", err)
+		}
+		defer f.Close()
+		out = f
+	} else if outIfEmpty {
+		out = os.Stdout
+	} else {
+		return nil
+	}
+	enc := json.NewEncoder(out)
+	if err := enc.Encode(value); err != nil {
+		return fmt.Errorf("failed to encode to JSON: %w", err)
+	}
+	_, err := out.Write([]byte{'\n'})
+	if err != nil {
+		return fmt.Errorf("failed to append new-line: %w", err)
+	}
+	return nil
+}

cmd/load_elf.go

@@ -2,10 +2,7 @@ package cmd
 
 import (
 	"debug/elf"
-	"encoding/json"
 	"fmt"
-	"io"
-	"os"
 
 	"github.com/urfave/cli/v2"
 
@@ -56,23 +53,7 @@ func LoadELF(ctx *cli.Context) error {
 			return fmt.Errorf("failed to apply patch %s: %w", typ, err)
 		}
 	}
-	p := ctx.Path(LoadELFOutFlag.Name)
-	var out io.Writer
-	if p != "" {
-		f, err := os.OpenFile(p, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0755)
-		if err != nil {
-			return fmt.Errorf("failed to open output file: %w", err)
-		}
-		defer f.Close()
-		out = f
-	} else {
-		out = os.Stdout
-	}
-	enc := json.NewEncoder(out)
-	if err := enc.Encode(state); err != nil {
-		return fmt.Errorf("failed to encode state to JSON: %w", err)
-	}
-	return nil
+	return writeJSON[*mipsevm.State](ctx.Path(LoadELFOutFlag.Name), state, true)
 }
 
 var LoadELFCommand = &cli.Command{

cmd/log.go

+package cmd
+
+import (
+	"io"
+
+	"github.com/ethereum/go-ethereum/log"
+)
+
+func Logger(w io.Writer, lvl log.Lvl) log.Logger {
+	h := log.StreamHandler(w, log.LogfmtFormat())
+	h = log.SyncHandler(h)
+	h = log.LvlFilterHandler(lvl, h)
+	l := log.New()
+	l.SetHandler(h)
+	return l
+}

cmd/matcher.go

+package cmd
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"cannon/mipsevm"
+)
+
+type StepMatcher func(st *mipsevm.State) bool
+
+type StepMatcherFlag struct {
+	repr    string
+	matcher StepMatcher
+}
+
+func (m *StepMatcherFlag) Set(value string) error {
+	m.repr = value
+	if value == "" || value == "never" {
+		m.matcher = func(st *mipsevm.State) bool {
+			return false
+		}
+	} else if value == "always" {
+		m.matcher = func(st *mipsevm.State) bool {
+			return true
+		}
+	} else if strings.HasPrefix(value, "=") {
+		when, err := strconv.ParseUint(value[1:], 0, 64)
+		if err != nil {
+			return fmt.Errorf("failed to parse step number: %w", err)
+		}
+		m.matcher = func(st *mipsevm.State) bool {
+			return st.Step == when
+		}
+	} else if strings.HasPrefix(value, "%") {
+		when, err := strconv.ParseUint(value[1:], 0, 64)
+		if err != nil {
+			return fmt.Errorf("failed to parse step interval number: %w", err)
+		}
+		m.matcher = func(st *mipsevm.State) bool {
+			return st.Step%when == 0
+		}
+	} else {
+		return fmt.Errorf("unrecognized step matcher: %q", value)
+	}
+	return nil
+}
+
+func (m *StepMatcherFlag) String() string {
+	return m.repr
+}
+
+func (m *StepMatcherFlag) Matcher() StepMatcher {
+	if m.matcher == nil { // Set(value) is not called for omitted inputs, default to never matching.
+		return func(st *mipsevm.State) bool {
+			return false
+		}
+	}
+	return m.matcher
+}

cmd/run.go

+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/urfave/cli/v2"
+
+	"cannon/mipsevm"
+)
+
+var (
+	RunInputFlag = &cli.PathFlag{
+		Name:      "input",
+		Usage:     "path of input JSON state. Stdin if left empty.",
+		TakesFile: true,
+		Value:     "state.json",
+		Required:  true,
+	}
+	RunOutputFlag = &cli.PathFlag{
+		Name:      "output",
+		Usage:     "path of output JSON state. Stdout if left empty.",
+		TakesFile: true,
+		Value:     "out.json",
+		Required:  false,
+	}
+	patternHelp    = "'never' (default), 'always', '=123' at exactly step 123, '%123' for every 123 steps"
+	RunProofAtFlag = &cli.GenericFlag{
+		Name:     "proof-at",
+		Usage:    "step pattern to output proof at: " + patternHelp,
+		Value:    new(StepMatcherFlag),
+		Required: false,
+	}
+	RunProofFmtFlag = &cli.StringFlag{
+		Name:     "proof-fmt",
+		Usage:    "format for proof data output file names. Proof data is written to stdout if empty.",
+		Value:    "proof-%d.json",
+		Required: false,
+	}
+	RunSnapshotAtFlag = &cli.GenericFlag{
+		Name:     "snapshot-at",
+		Usage:    "step pattern to output snapshots at: " + patternHelp,
+		Value:    new(StepMatcherFlag),
+		Required: false,
+	}
+	RunSnapshotFmtFlag = &cli.StringFlag{
+		Name:     "snapshot-fmt",
+		Usage:    "format for snapshot output file names.",
+		Value:    "state-%d.json",
+		Required: false,
+	}
+	RunStopAtFlag = &cli.GenericFlag{
+		Name:     "stop-at",
+		Usage:    "step pattern to stop at: " + patternHelp,
+		Value:    new(StepMatcherFlag),
+		Required: false,
+	}
+)
+
+type Proof struct {
+	Step uint64 `json:"step"`
+
+	Pre  common.Hash `json:"pre"`
+	Post common.Hash `json:"post"`
+
+	StepInput   hexutil.Bytes `json:"step-input"`
+	OracleInput hexutil.Bytes `json:"oracle-input"`
+}
+
+func Run(ctx *cli.Context) error {
+	state, err := loadJSON[mipsevm.State](ctx.Path(RunInputFlag.Name))
+	if err != nil {
+		return err
+	}
+	mu, err := mipsevm.NewUnicorn()
+	if err != nil {
+		return fmt.Errorf("failed to create unicorn emulator: %w", err)
+	}
+	if err := mipsevm.LoadUnicorn(state, mu); err != nil {
+		return fmt.Errorf("failed to load state into unicorn emulator: %w", err)
+	}
+	l := Logger(os.Stderr, log.LvlInfo)
+	outLog := &mipsevm.LoggingWriter{Name: "program std-out", Log: l}
+	errLog := &mipsevm.LoggingWriter{Name: "program std-err", Log: l}
+
+	var po mipsevm.PreimageOracle // TODO need to set this up
+
+	stopAt := ctx.Generic(RunStopAtFlag.Name).(*StepMatcherFlag).Matcher()
+	proofAt := ctx.Generic(RunProofAtFlag.Name).(*StepMatcherFlag).Matcher()
+	snapshotAt := ctx.Generic(RunSnapshotAtFlag.Name).(*StepMatcherFlag).Matcher()
+
+	us, err := mipsevm.NewUnicornState(mu, state, po, outLog, errLog)
+	if err != nil {
+		return fmt.Errorf("failed to setup instrumented VM state: %w", err)
+	}
+	proofFmt := ctx.String(RunProofFmtFlag.Name)
+	snapshotFmt := ctx.String(RunSnapshotFmtFlag.Name)
+
+	for !state.Exited {
+		step := state.Step
+
+		if stopAt(state) {
+			break
+		}
+
+		if snapshotAt(state) {
+			if err := writeJSON[*mipsevm.State](fmt.Sprintf(snapshotFmt, step), state, false); err != nil {
+				return fmt.Errorf("failed to write state snapshot: %w", err)
+			}
+		}
+
+		if proofAt(state) {
+			preStateHash := crypto.Keccak256Hash(state.EncodeWitness())
+			witness := us.Step(true)
+			postStateHash := crypto.Keccak256Hash(state.EncodeWitness())
+			proof := &Proof{
+				Step:      step,
+				Pre:       preStateHash,
+				Post:      postStateHash,
+				StepInput: witness.EncodeStepInput(),
+			}
+			if witness.HasPreimage() {
+				proof.OracleInput, err = witness.EncodePreimageOracleInput()
+				if err != nil {
+					return fmt.Errorf("failed to encode pre-image oracle input: %w", err)
+				}
+			}
+			if err := writeJSON[*Proof](fmt.Sprintf(proofFmt, step), proof, true); err != nil {
+				return fmt.Errorf("failed to write proof data: %w", err)
+			}
+		} else {
+			_ = us.Step(false)
+		}
+	}
+
+	if err := writeJSON[*mipsevm.State](ctx.Path(RunOutputFlag.Name), state, true); err != nil {
+		return fmt.Errorf("failed to write state output: %w", err)
+	}
+	return nil
+}
+
+var RunCommand = &cli.Command{
+	Name:        "run",
+	Usage:       "Run VM step(s) and generate proof data to replicate onchain.",
+	Description: "Run VM step(s) and generate proof data to replicate onchain. See flags to match when to output a proof, a snapshot, or to stop early.",
+	Action:      Run,
+	Flags: []cli.Flag{
+		RunInputFlag,
+		RunOutputFlag,
+		RunProofAtFlag,
+		RunProofFmtFlag,
+		RunSnapshotAtFlag,
+		RunSnapshotFmtFlag,
+		RunStopAtFlag,
+	},
+}

cmd/run_steps.go

-package cmd
-
-import "github.com/urfave/cli/v2"
-
-func RunSteps(ctx *cli.Context) error {
-	// TODO
-	return nil
-}
-
-var RunStepsCommand = &cli.Command{
-	Name:        "run-steps",
-	Usage:       "",
-	Description: "",
-	Action:      RunSteps,
-	Flags:       nil,
-}

main.go

@@ -16,8 +16,7 @@ func main() {
 	app.Description = "MIPS Fault Proof tool"
 	app.Commands = []*cli.Command{
 		cmd.LoadELFCommand,
-		cmd.RunStepsCommand,
-		cmd.GenProofCommand,
+		cmd.RunCommand,
 	}
 	err := app.Run(os.Args)
 	if err != nil {

mipsevm/logw.go

+package mipsevm
+
+import (
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+// LoggingWriter is a simple util to wrap a logger,
+// and expose an io Writer interface,
+// for the program running within the VM to write to.
+type LoggingWriter struct {
+	Name string
+	Log  log.Logger
+}
+
+func logAsText(b string) bool {
+	for _, c := range b {
+		if (c < 0x20 || c >= 0x7F) && (c != '\n' && c != '\t') {
+			return false
+		}
+	}
+	return true
+}
+
+func (lw *LoggingWriter) Write(b []byte) (int, error) {
+	t := string(b)
+	if logAsText(t) {
+		lw.Log.Info("", "text", t)
+	} else {
+		lw.Log.Info("", "data", hexutil.Bytes(b))
+	}
+	return len(b), nil
+}