From b8dc1e2705211aedaa40a2fb4ee3c9fabb664a51 Mon Sep 17 00:00:00 2001 From: Martin Holst Swende Date: Mon, 18 Oct 2021 13:38:00 +0200 Subject: [PATCH] cmd/rlpdump: add support for text to rlp (#23745) This PR adds support for the rlpdump tool to go from text format to RLP. --- cmd/rlpdump/main.go | 109 ++++++++++++++++++++++++++++-------- cmd/rlpdump/rlpdump_test.go | 65 +++++++++++++++++++++ 2 files changed, 151 insertions(+), 23 deletions(-) create mode 100644 cmd/rlpdump/rlpdump_test.go diff --git a/cmd/rlpdump/main.go b/cmd/rlpdump/main.go index d0f993c5b..9c0af0124 100644 --- a/cmd/rlpdump/main.go +++ b/cmd/rlpdump/main.go @@ -18,7 +18,9 @@ package main import ( + "bufio" "bytes" + "container/list" "encoding/hex" "flag" "fmt" @@ -26,18 +28,20 @@ import ( "os" "strings" + "github.com/ethereum/go-ethereum/common" "github.com/ethereum/go-ethereum/rlp" ) var ( - hexMode = flag.String("hex", "", "dump given hex data") - noASCII = flag.Bool("noascii", false, "don't print ASCII strings readably") - single = flag.Bool("single", false, "print only the first element, discard the rest") + hexMode = flag.String("hex", "", "dump given hex data") + reverseMode = flag.Bool("reverse", false, "convert ASCII to rlp") + noASCII = flag.Bool("noascii", false, "don't print ASCII strings readably") + single = flag.Bool("single", false, "print only the first element, discard the rest") ) func init() { flag.Usage = func() { - fmt.Fprintln(os.Stderr, "Usage:", os.Args[0], "[-noascii] [-hex ] [filename]") + fmt.Fprintln(os.Stderr, "Usage:", os.Args[0], "[-noascii] [-hex ][-reverse] [filename]") flag.PrintDefaults() fmt.Fprintln(os.Stderr, ` Dumps RLP data from the given file in readable form. @@ -73,23 +77,40 @@ func main() { flag.Usage() os.Exit(2) } - - s := rlp.NewStream(r, 0) - for { - if err := dump(s, 0); err != nil { - if err != io.EOF { - die(err) - } - break + out := os.Stdout + if *reverseMode { + data, err := textToRlp(r) + if err != nil { + die(err) } - fmt.Println() - if *single { - break + fmt.Printf("0x%x\n", data) + return + } else { + err := rlpToText(r, out) + if err != nil { + die(err) } } } -func dump(s *rlp.Stream, depth int) error { +func rlpToText(r io.Reader, out io.Writer) error { + s := rlp.NewStream(r, 0) + for { + if err := dump(s, 0, out); err != nil { + if err != io.EOF { + return err + } + break + } + fmt.Fprintln(out) + if *single { + break + } + } + return nil +} + +func dump(s *rlp.Stream, depth int, out io.Writer) error { kind, size, err := s.Kind() if err != nil { return err @@ -101,28 +122,28 @@ func dump(s *rlp.Stream, depth int) error { return err } if len(str) == 0 || !*noASCII && isASCII(str) { - fmt.Printf("%s%q", ws(depth), str) + fmt.Fprintf(out, "%s%q", ws(depth), str) } else { - fmt.Printf("%s%x", ws(depth), str) + fmt.Fprintf(out, "%s%x", ws(depth), str) } case rlp.List: s.List() defer s.ListEnd() if size == 0 { - fmt.Print(ws(depth) + "[]") + fmt.Fprintf(out, ws(depth)+"[]") } else { - fmt.Println(ws(depth) + "[") + fmt.Fprintln(out, ws(depth)+"[") for i := 0; ; i++ { if i > 0 { - fmt.Print(",\n") + fmt.Fprint(out, ",\n") } - if err := dump(s, depth+1); err == rlp.EOL { + if err := dump(s, depth+1, out); err == rlp.EOL { break } else if err != nil { return err } } - fmt.Print(ws(depth) + "]") + fmt.Fprint(out, ws(depth)+"]") } } return nil @@ -145,3 +166,45 @@ func die(args ...interface{}) { fmt.Fprintln(os.Stderr, args...) os.Exit(1) } + +// textToRlp converts text into RLP (best effort). +func textToRlp(r io.Reader) ([]byte, error) { + // We're expecting the input to be well-formed, meaning that + // - each element is on a separate line + // - each line is either an (element OR a list start/end) + comma + // - an element is either hex-encoded bytes OR a quoted string + var ( + scanner = bufio.NewScanner(r) + obj []interface{} + stack = list.New() + ) + for scanner.Scan() { + t := strings.TrimSpace(scanner.Text()) + if len(t) == 0 { + continue + } + switch t { + case "[": // list start + stack.PushFront(obj) + obj = make([]interface{}, 0) + case "]", "],": // list end + parent := stack.Remove(stack.Front()).([]interface{}) + obj = append(parent, obj) + case "[],": // empty list + obj = append(obj, make([]interface{}, 0)) + default: // element + data := []byte(t)[:len(t)-1] // cut off comma + if data[0] == '"' { // ascii string + data = []byte(t)[1 : len(data)-1] + } else { // hex data + data = common.FromHex(string(data)) + } + obj = append(obj, data) + } + } + if err := scanner.Err(); err != nil { + return nil, err + } + data, err := rlp.EncodeToBytes(obj[0]) + return data, err +} diff --git a/cmd/rlpdump/rlpdump_test.go b/cmd/rlpdump/rlpdump_test.go new file mode 100644 index 000000000..ea607e380 --- /dev/null +++ b/cmd/rlpdump/rlpdump_test.go @@ -0,0 +1,65 @@ +package main + +import ( + "bytes" + "fmt" + "strings" + "testing" + + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/common/hexutil" +) + +func TestRoundtrip(t *testing.T) { + for i, want := range []string{ + "0xf880806482520894d0d0d0d0d0d0d0d0d0d0d0d0d0d0d0d0d0d0d0d0a1010000000000000000000000000000000000000000000000000000000000000001801ba0c16787a8e25e941d67691954642876c08f00996163ae7dfadbbfd6cd436f549da06180e5626cae31590f40641fe8f63734316c4bfeb4cdfab6714198c1044d2e28", + "0xd5c0d3cb84746573742a2a808213378667617a6f6e6b", + "0xc780c0c1c0825208", + } { + var out strings.Builder + err := rlpToText(bytes.NewReader(common.FromHex(want)), &out) + if err != nil { + t.Fatal(err) + } + text := out.String() + rlpBytes, err := textToRlp(strings.NewReader(text)) + if err != nil { + t.Errorf("test %d: error %v", i, err) + continue + } + have := fmt.Sprintf("0x%x", rlpBytes) + if have != want { + t.Errorf("test %d: have\n%v\nwant:\n%v\n", i, have, want) + } + } +} + +func TestTextToRlp(t *testing.T) { + type tc struct { + text string + want string + } + cases := []tc{ + { + text: `[ + "", + [], +[ + [], + ], + 5208, +]`, + want: "0xc780c0c1c0825208", + }, + } + for i, tc := range cases { + have, err := textToRlp(strings.NewReader(tc.text)) + if err != nil { + t.Errorf("test %d: error %v", i, err) + continue + } + if hexutil.Encode(have) != tc.want { + t.Errorf("test %d:\nhave %v\nwant %v", i, hexutil.Encode(have), tc.want) + } + } +}