Official Go implementation of the Ethereum protocol
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go-ethereum/rpc/json.go

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// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package rpc
import (
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"io"
"reflect"
"strings"
"sync"
"time"
)
const (
vsn = "2.0"
serviceMethodSeparator = "_"
subscribeMethodSuffix = "_subscribe"
unsubscribeMethodSuffix = "_unsubscribe"
notificationMethodSuffix = "_subscription"
defaultWriteTimeout = 10 * time.Second // used if context has no deadline
)
var null = json.RawMessage("null")
type subscriptionResult struct {
ID string `json:"subscription"`
Result json.RawMessage `json:"result,omitempty"`
}
// A value of this type can a JSON-RPC request, notification, successful response or
// error response. Which one it is depends on the fields.
type jsonrpcMessage struct {
Version string `json:"jsonrpc,omitempty"`
ID json.RawMessage `json:"id,omitempty"`
Method string `json:"method,omitempty"`
Params json.RawMessage `json:"params,omitempty"`
Error *jsonError `json:"error,omitempty"`
Result json.RawMessage `json:"result,omitempty"`
}
func (msg *jsonrpcMessage) isNotification() bool {
return msg.hasValidVersion() && msg.ID == nil && msg.Method != ""
}
func (msg *jsonrpcMessage) isCall() bool {
return msg.hasValidVersion() && msg.hasValidID() && msg.Method != ""
}
func (msg *jsonrpcMessage) isResponse() bool {
return msg.hasValidVersion() && msg.hasValidID() && msg.Method == "" && msg.Params == nil && (msg.Result != nil || msg.Error != nil)
}
func (msg *jsonrpcMessage) hasValidID() bool {
return len(msg.ID) > 0 && msg.ID[0] != '{' && msg.ID[0] != '['
}
func (msg *jsonrpcMessage) hasValidVersion() bool {
return msg.Version == vsn
}
func (msg *jsonrpcMessage) isSubscribe() bool {
return strings.HasSuffix(msg.Method, subscribeMethodSuffix)
}
func (msg *jsonrpcMessage) isUnsubscribe() bool {
return strings.HasSuffix(msg.Method, unsubscribeMethodSuffix)
}
func (msg *jsonrpcMessage) namespace() string {
elem := strings.SplitN(msg.Method, serviceMethodSeparator, 2)
return elem[0]
}
func (msg *jsonrpcMessage) String() string {
b, _ := json.Marshal(msg)
return string(b)
}
func (msg *jsonrpcMessage) errorResponse(err error) *jsonrpcMessage {
resp := errorMessage(err)
resp.ID = msg.ID
return resp
}
func (msg *jsonrpcMessage) response(result interface{}) *jsonrpcMessage {
enc, err := json.Marshal(result)
if err != nil {
return msg.errorResponse(&internalServerError{errcodeMarshalError, err.Error()})
}
return &jsonrpcMessage{Version: vsn, ID: msg.ID, Result: enc}
}
func errorMessage(err error) *jsonrpcMessage {
msg := &jsonrpcMessage{Version: vsn, ID: null, Error: &jsonError{
Code: errcodeDefault,
Message: err.Error(),
}}
ec, ok := err.(Error)
if ok {
msg.Error.Code = ec.ErrorCode()
}
internal/ethapi: return revert reason for eth_call (#21083) * internal/ethapi: return revert reason for eth_call * internal/ethapi: moved revert reason logic to doCall * accounts/abi/bind/backends: added revert reason logic to simulated backend * internal/ethapi: fixed linting error * internal/ethapi: check if require reason can be unpacked * internal/ethapi: better error logic * internal/ethapi: simplify logic * internal/ethapi: return vmError() * internal/ethapi: move handling of revert out of docall * graphql: removed revert logic until spec change * rpc: internal/ethapi: added custom error types * graphql: use returndata instead of return Return() checks if there is an error. If an error is found, we return nil. For most use cases it can be beneficial to return the output even if there was an error. This code should be changed anyway once the spec supports error reasons in graphql responses * accounts/abi/bind/backends: added tests for revert reason * internal/ethapi: add errorCode to revert error * internal/ethapi: add errorCode of 3 to revertError * internal/ethapi: unified estimateGasErrors, simplified logic * internal/ethapi: unified handling of errors in DoEstimateGas * rpc: print error data field * accounts/abi/bind/backends: unify simulatedBackend and RPC * internal/ethapi: added binary data to revertError data * internal/ethapi: refactored unpacking logic into newRevertError * accounts/abi/bind/backends: fix EstimateGas * accounts, console, internal, rpc: minor error interface cleanups * Revert "accounts, console, internal, rpc: minor error interface cleanups" This reverts commit 2d3ef53c5304e429a04983210a417c1f4e0dafb7. * re-apply the good parts of 2d3ef53c53 * rpc: add test for returning server error data from client Co-authored-by: rjl493456442 <garyrong0905@gmail.com> Co-authored-by: Péter Szilágyi <peterke@gmail.com> Co-authored-by: Felix Lange <fjl@twurst.com>
4 years ago
de, ok := err.(DataError)
if ok {
msg.Error.Data = de.ErrorData()
}
return msg
}
type jsonError struct {
Code int `json:"code"`
Message string `json:"message"`
Data interface{} `json:"data,omitempty"`
}
func (err *jsonError) Error() string {
if err.Message == "" {
return fmt.Sprintf("json-rpc error %d", err.Code)
}
return err.Message
}
func (err *jsonError) ErrorCode() int {
return err.Code
}
internal/ethapi: return revert reason for eth_call (#21083) * internal/ethapi: return revert reason for eth_call * internal/ethapi: moved revert reason logic to doCall * accounts/abi/bind/backends: added revert reason logic to simulated backend * internal/ethapi: fixed linting error * internal/ethapi: check if require reason can be unpacked * internal/ethapi: better error logic * internal/ethapi: simplify logic * internal/ethapi: return vmError() * internal/ethapi: move handling of revert out of docall * graphql: removed revert logic until spec change * rpc: internal/ethapi: added custom error types * graphql: use returndata instead of return Return() checks if there is an error. If an error is found, we return nil. For most use cases it can be beneficial to return the output even if there was an error. This code should be changed anyway once the spec supports error reasons in graphql responses * accounts/abi/bind/backends: added tests for revert reason * internal/ethapi: add errorCode to revert error * internal/ethapi: add errorCode of 3 to revertError * internal/ethapi: unified estimateGasErrors, simplified logic * internal/ethapi: unified handling of errors in DoEstimateGas * rpc: print error data field * accounts/abi/bind/backends: unify simulatedBackend and RPC * internal/ethapi: added binary data to revertError data * internal/ethapi: refactored unpacking logic into newRevertError * accounts/abi/bind/backends: fix EstimateGas * accounts, console, internal, rpc: minor error interface cleanups * Revert "accounts, console, internal, rpc: minor error interface cleanups" This reverts commit 2d3ef53c5304e429a04983210a417c1f4e0dafb7. * re-apply the good parts of 2d3ef53c53 * rpc: add test for returning server error data from client Co-authored-by: rjl493456442 <garyrong0905@gmail.com> Co-authored-by: Péter Szilágyi <peterke@gmail.com> Co-authored-by: Felix Lange <fjl@twurst.com>
4 years ago
func (err *jsonError) ErrorData() interface{} {
return err.Data
}
// Conn is a subset of the methods of net.Conn which are sufficient for ServerCodec.
type Conn interface {
io.ReadWriteCloser
SetWriteDeadline(time.Time) error
}
type deadlineCloser interface {
io.Closer
SetWriteDeadline(time.Time) error
}
// ConnRemoteAddr wraps the RemoteAddr operation, which returns a description
// of the peer address of a connection. If a Conn also implements ConnRemoteAddr, this
// description is used in log messages.
type ConnRemoteAddr interface {
RemoteAddr() string
}
// jsonCodec reads and writes JSON-RPC messages to the underlying connection. It also has
// support for parsing arguments and serializing (result) objects.
type jsonCodec struct {
remote string
closer sync.Once // close closed channel once
closeCh chan interface{} // closed on Close
decode func(v interface{}) error // decoder to allow multiple transports
encMu sync.Mutex // guards the encoder
encode func(v interface{}) error // encoder to allow multiple transports
conn deadlineCloser
}
// NewFuncCodec creates a codec which uses the given functions to read and write. If conn
// implements ConnRemoteAddr, log messages will use it to include the remote address of
// the connection.
func NewFuncCodec(conn deadlineCloser, encode, decode func(v interface{}) error) ServerCodec {
codec := &jsonCodec{
closeCh: make(chan interface{}),
encode: encode,
decode: decode,
conn: conn,
}
if ra, ok := conn.(ConnRemoteAddr); ok {
codec.remote = ra.RemoteAddr()
}
return codec
}
// NewCodec creates a codec on the given connection. If conn implements ConnRemoteAddr, log
// messages will use it to include the remote address of the connection.
func NewCodec(conn Conn) ServerCodec {
enc := json.NewEncoder(conn)
dec := json.NewDecoder(conn)
dec.UseNumber()
return NewFuncCodec(conn, enc.Encode, dec.Decode)
}
func (c *jsonCodec) peerInfo() PeerInfo {
// This returns "ipc" because all other built-in transports have a separate codec type.
return PeerInfo{Transport: "ipc", RemoteAddr: c.remote}
}
func (c *jsonCodec) remoteAddr() string {
return c.remote
}
func (c *jsonCodec) readBatch() (messages []*jsonrpcMessage, batch bool, err error) {
// Decode the next JSON object in the input stream.
// This verifies basic syntax, etc.
var rawmsg json.RawMessage
if err := c.decode(&rawmsg); err != nil {
return nil, false, err
}
messages, batch = parseMessage(rawmsg)
for i, msg := range messages {
if msg == nil {
// Message is JSON 'null'. Replace with zero value so it
// will be treated like any other invalid message.
messages[i] = new(jsonrpcMessage)
}
}
return messages, batch, nil
}
func (c *jsonCodec) writeJSON(ctx context.Context, v interface{}) error {
c.encMu.Lock()
defer c.encMu.Unlock()
deadline, ok := ctx.Deadline()
if !ok {
deadline = time.Now().Add(defaultWriteTimeout)
}
c.conn.SetWriteDeadline(deadline)
return c.encode(v)
}
func (c *jsonCodec) close() {
c.closer.Do(func() {
close(c.closeCh)
c.conn.Close()
})
}
// Closed returns a channel which will be closed when Close is called
func (c *jsonCodec) closed() <-chan interface{} {
return c.closeCh
}
// parseMessage parses raw bytes as a (batch of) JSON-RPC message(s). There are no error
// checks in this function because the raw message has already been syntax-checked when it
// is called. Any non-JSON-RPC messages in the input return the zero value of
// jsonrpcMessage.
func parseMessage(raw json.RawMessage) ([]*jsonrpcMessage, bool) {
if !isBatch(raw) {
msgs := []*jsonrpcMessage{{}}
json.Unmarshal(raw, &msgs[0])
return msgs, false
}
dec := json.NewDecoder(bytes.NewReader(raw))
dec.Token() // skip '['
var msgs []*jsonrpcMessage
for dec.More() {
msgs = append(msgs, new(jsonrpcMessage))
dec.Decode(&msgs[len(msgs)-1])
}
return msgs, true
}
// isBatch returns true when the first non-whitespace characters is '['
func isBatch(raw json.RawMessage) bool {
for _, c := range raw {
// skip insignificant whitespace (http://www.ietf.org/rfc/rfc4627.txt)
if c == 0x20 || c == 0x09 || c == 0x0a || c == 0x0d {
continue
}
return c == '['
}
return false
}
// parsePositionalArguments tries to parse the given args to an array of values with the
// given types. It returns the parsed values or an error when the args could not be
// parsed. Missing optional arguments are returned as reflect.Zero values.
func parsePositionalArguments(rawArgs json.RawMessage, types []reflect.Type) ([]reflect.Value, error) {
dec := json.NewDecoder(bytes.NewReader(rawArgs))
var args []reflect.Value
tok, err := dec.Token()
switch {
case err == io.EOF || tok == nil && err == nil:
// "params" is optional and may be empty. Also allow "params":null even though it's
// not in the spec because our own client used to send it.
case err != nil:
return nil, err
case tok == json.Delim('['):
// Read argument array.
if args, err = parseArgumentArray(dec, types); err != nil {
return nil, err
}
default:
return nil, errors.New("non-array args")
}
// Set any missing args to nil.
for i := len(args); i < len(types); i++ {
if types[i].Kind() != reflect.Ptr {
return nil, fmt.Errorf("missing value for required argument %d", i)
}
args = append(args, reflect.Zero(types[i]))
}
return args, nil
}
func parseArgumentArray(dec *json.Decoder, types []reflect.Type) ([]reflect.Value, error) {
args := make([]reflect.Value, 0, len(types))
for i := 0; dec.More(); i++ {
if i >= len(types) {
return args, fmt.Errorf("too many arguments, want at most %d", len(types))
}
argval := reflect.New(types[i])
if err := dec.Decode(argval.Interface()); err != nil {
return args, fmt.Errorf("invalid argument %d: %v", i, err)
}
if argval.IsNil() && types[i].Kind() != reflect.Ptr {
return args, fmt.Errorf("missing value for required argument %d", i)
}
args = append(args, argval.Elem())
}
// Read end of args array.
_, err := dec.Token()
return args, err
}
// parseSubscriptionName extracts the subscription name from an encoded argument array.
func parseSubscriptionName(rawArgs json.RawMessage) (string, error) {
dec := json.NewDecoder(bytes.NewReader(rawArgs))
if tok, _ := dec.Token(); tok != json.Delim('[') {
return "", errors.New("non-array args")
}
v, _ := dec.Token()
method, ok := v.(string)
if !ok {
return "", errors.New("expected subscription name as first argument")
}
return method, nil
}