// 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 whisper
import (
"encoding/json"
"fmt"
"sync"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/rpc"
)
// PublicWhisperAPI provides the whisper RPC service.
type PublicWhisperAPI struct {
w *Whisper
messagesMu sync.RWMutex
messages map[int]*whisperFilter
}
type whisperOfflineError struct{}
func (e *whisperOfflineError) Error() string {
return "whisper is offline"
}
// whisperOffLineErr is returned when the node doesn't offer the shh service.
var whisperOffLineErr = new(whisperOfflineError)
// NewPublicWhisperAPI create a new RPC whisper service.
func NewPublicWhisperAPI(w *Whisper) *PublicWhisperAPI {
return &PublicWhisperAPI{w: w, messages: make(map[int]*whisperFilter)}
}
// Version returns the Whisper version this node offers.
func (s *PublicWhisperAPI) Version() (*rpc.HexNumber, error) {
if s.w == nil {
return rpc.NewHexNumber(0), whisperOffLineErr
}
return rpc.NewHexNumber(s.w.Version()), nil
}
// HasIdentity checks if the the whisper node is configured with the private key
// of the specified public pair.
func (s *PublicWhisperAPI) HasIdentity(identity string) (bool, error) {
if s.w == nil {
return false, whisperOffLineErr
}
return s.w.HasIdentity(crypto.ToECDSAPub(common.FromHex(identity))), nil
}
// NewIdentity generates a new cryptographic identity for the client, and injects
// it into the known identities for message decryption.
func (s *PublicWhisperAPI) NewIdentity() (string, error) {
if s.w == nil {
return "", whisperOffLineErr
}
identity := s.w.NewIdentity()
return common.ToHex(crypto.FromECDSAPub(&identity.PublicKey)), nil
}
type NewFilterArgs struct {
To string
From string
Topics [][][]byte
}
// NewWhisperFilter creates and registers a new message filter to watch for inbound whisper messages.
func (s *PublicWhisperAPI) NewFilter(args NewFilterArgs) (*rpc.HexNumber, error) {
if s.w == nil {
return nil, whisperOffLineErr
}
var id int
filter := Filter{
To: crypto.ToECDSAPub(common.FromHex(args.To)),
From: crypto.ToECDSAPub(common.FromHex(args.From)),
Topics: NewFilterTopics(args.Topics...),
Fn: func(message *Message) {
wmsg := NewWhisperMessage(message)
s.messagesMu.RLock() // Only read lock to the filter pool
defer s.messagesMu.RUnlock()
if s.messages[id] != nil {
s.messages[id].insert(wmsg)
}
},
}
id = s.w.Watch(filter)
s.messagesMu.Lock()
s.messages[id] = newWhisperFilter(id, s.w)
s.messagesMu.Unlock()
return rpc.NewHexNumber(id), nil
}
// GetFilterChanges retrieves all the new messages matched by a filter since the last retrieval.
func (s *PublicWhisperAPI) GetFilterChanges(filterId rpc.HexNumber) []WhisperMessage {
s.messagesMu.RLock()
defer s.messagesMu.RUnlock()
if s.messages[filterId.Int()] != nil {
if changes := s.messages[filterId.Int()].retrieve(); changes != nil {
return changes
}
}
return returnWhisperMessages(nil)
}
// UninstallFilter disables and removes an existing filter.
func (s *PublicWhisperAPI) UninstallFilter(filterId rpc.HexNumber) bool {
s.messagesMu.Lock()
defer s.messagesMu.Unlock()
if _, ok := s.messages[filterId.Int()]; ok {
delete(s.messages, filterId.Int())
return true
}
return false
}
// GetMessages retrieves all the known messages that match a specific filter.
func (s *PublicWhisperAPI) GetMessages(filterId rpc.HexNumber) []WhisperMessage {
// Retrieve all the cached messages matching a specific, existing filter
s.messagesMu.RLock()
defer s.messagesMu.RUnlock()
var messages []*Message
if s.messages[filterId.Int()] != nil {
messages = s.messages[filterId.Int()].messages()
}
return returnWhisperMessages(messages)
}
// returnWhisperMessages converts aNhisper message to a RPC whisper message.
func returnWhisperMessages(messages []*Message) []WhisperMessage {
msgs := make([]WhisperMessage, len(messages))
for i, msg := range messages {
msgs[i] = NewWhisperMessage(msg)
}
return msgs
}
type PostArgs struct {
From string `json:"from"`
To string `json:"to"`
Topics [][]byte `json:"topics"`
Payload string `json:"payload"`
Priority int64 `json:"priority"`
TTL int64 `json:"ttl"`
}
// Post injects a message into the whisper network for distribution.
func (s *PublicWhisperAPI) Post(args PostArgs) (bool, error) {
if s.w == nil {
return false, whisperOffLineErr
}
// construct whisper message with transmission options
message := NewMessage(common.FromHex(args.Payload))
options := Options{
To: crypto.ToECDSAPub(common.FromHex(args.To)),
TTL: time.Duration(args.TTL) * time.Second,
Topics: NewTopics(args.Topics...),
}
// set sender identity
if len(args.From) > 0 {
if key := s.w.GetIdentity(crypto.ToECDSAPub(common.FromHex(args.From))); key != nil {
options.From = key
} else {
return false, fmt.Errorf("unknown identity to send from: %s", args.From)
}
}
// Wrap and send the message
pow := time.Duration(args.Priority) * time.Millisecond
envelope, err := message.Wrap(pow, options)
if err != nil {
return false, err
}
return true, s.w.Send(envelope)
}
// WhisperMessage is the RPC representation of a whisper message.
type WhisperMessage struct {
ref *Message
Payload string `json:"payload"`
To string `json:"to"`
From string `json:"from"`
Sent int64 `json:"sent"`
TTL int64 `json:"ttl"`
Hash string `json:"hash"`
}
func (args *PostArgs) UnmarshalJSON(data []byte) (err error) {
var obj struct {
From string `json:"from"`
To string `json:"to"`
Topics []string `json:"topics"`
Payload string `json:"payload"`
Priority rpc.HexNumber `json:"priority"`
TTL rpc.HexNumber `json:"ttl"`
}
if err := json.Unmarshal(data, &obj); err != nil {
return err
}
args.From = obj.From
args.To = obj.To
args.Payload = obj.Payload
args.Priority = obj.Priority.Int64()
args.TTL = obj.TTL.Int64()
// decode topic strings
args.Topics = make([][]byte, len(obj.Topics))
for i, topic := range obj.Topics {
args.Topics[i] = common.FromHex(topic)
}
return nil
}
// UnmarshalJSON implements the json.Unmarshaler interface, invoked to convert a
// JSON message blob into a WhisperFilterArgs structure.
func (args *NewFilterArgs) UnmarshalJSON(b []byte) (err error) {
// Unmarshal the JSON message and sanity check
var obj struct {
To interface{} `json:"to"`
From interface{} `json:"from"`
Topics interface{} `json:"topics"`
}
if err := json.Unmarshal(b, &obj); err != nil {
return err
}
// Retrieve the simple data contents of the filter arguments
if obj.To == nil {
args.To = ""
} else {
argstr, ok := obj.To.(string)
if !ok {
return fmt.Errorf("to is not a string")
}
args.To = argstr
}
if obj.From == nil {
args.From = ""
} else {
argstr, ok := obj.From.(string)
if !ok {
return fmt.Errorf("from is not a string")
}
args.From = argstr
}
// Construct the nested topic array
if obj.Topics != nil {
// Make sure we have an actual topic array
list, ok := obj.Topics.([]interface{})
if !ok {
return fmt.Errorf("topics is not an array")
}
// Iterate over each topic and handle nil, string or array
topics := make([][]string, len(list))
for idx, field := range list {
switch value := field.(type) {
case nil:
topics[idx] = []string{}
case string:
topics[idx] = []string{value}
case []interface{}:
topics[idx] = make([]string, len(value))
for i, nested := range value {
switch value := nested.(type) {
case nil:
topics[idx][i] = ""
case string:
topics[idx][i] = value
default:
return fmt.Errorf("topic[%d][%d] is not a string", idx, i)
}
}
default:
return fmt.Errorf("topic[%d] not a string or array", idx)
}
}
topicsDecoded := make([][][]byte, len(topics))
for i, condition := range topics {
topicsDecoded[i] = make([][]byte, len(condition))
for j, topic := range condition {
topicsDecoded[i][j] = common.FromHex(topic)
}
}
args.Topics = topicsDecoded
}
return nil
}
// whisperFilter is the message cache matching a specific filter, accumulating
// inbound messages until the are requested by the client.
type whisperFilter struct {
id int // Filter identifier for old message retrieval
ref *Whisper // Whisper reference for old message retrieval
cache []WhisperMessage // Cache of messages not yet polled
skip map[common.Hash]struct{} // List of retrieved messages to avoid duplication
update time.Time // Time of the last message query
lock sync.RWMutex // Lock protecting the filter internals
}
// messages retrieves all the cached messages from the entire pool matching the
// filter, resetting the filter's change buffer.
func (w *whisperFilter) messages() []*Message {
w.lock.Lock()
defer w.lock.Unlock()
w.cache = nil
w.update = time.Now()
w.skip = make(map[common.Hash]struct{})
messages := w.ref.Messages(w.id)
for _, message := range messages {
w.skip[message.Hash] = struct{}{}
}
return messages
}
// insert injects a new batch of messages into the filter cache.
func (w *whisperFilter) insert(messages ...WhisperMessage) {
w.lock.Lock()
defer w.lock.Unlock()
for _, message := range messages {
if _, ok := w.skip[message.ref.Hash]; !ok {
w.cache = append(w.cache, messages...)
}
}
}
// retrieve fetches all the cached messages from the filter.
func (w *whisperFilter) retrieve() (messages []WhisperMessage) {
w.lock.Lock()
defer w.lock.Unlock()
messages, w.cache = w.cache, nil
w.update = time.Now()
return
}
// activity returns the last time instance when client requests were executed on
// the filter.
func (w *whisperFilter) activity() time.Time {
w.lock.RLock()
defer w.lock.RUnlock()
return w.update
}
// newWhisperFilter creates a new serialized, poll based whisper topic filter.
func newWhisperFilter(id int, ref *Whisper) *whisperFilter {
return &whisperFilter{
id: id,
ref: ref,
update: time.Now(),
skip: make(map[common.Hash]struct{}),
}
}
// NewWhisperMessage converts an internal message into an API version.
func NewWhisperMessage(message *Message) WhisperMessage {
return WhisperMessage{
ref: message,
Payload: common.ToHex(message.Payload),
From: common.ToHex(crypto.FromECDSAPub(message.Recover())),
To: common.ToHex(crypto.FromECDSAPub(message.To)),
Sent: message.Sent.Unix(),
TTL: int64(message.TTL / time.Second),
Hash: common.ToHex(message.Hash.Bytes()),
}
}
