ricochet-go/vendor/github.com/s-rah/go-ricochet/channels/chatchannel.go

155 lines
5.5 KiB
Go

package channels
import (
"crypto/rand"
"github.com/golang/protobuf/proto"
"github.com/s-rah/go-ricochet/utils"
"github.com/s-rah/go-ricochet/wire/chat"
"github.com/s-rah/go-ricochet/wire/control"
"math"
"math/big"
"time"
)
// ChatChannel implements the ChannelHandler interface for a channel of
// type "im.ricochet.chat". The channel may be inbound or outbound.
//
// ChatChannel implements protocol-level sanity and state validation, but
// does not handle or acknowledge chat messages. The application must provide
// a ChatChannelHandler implementation to handle chat events.
type ChatChannel struct {
// Methods of Handler are called for chat events on this channel
Handler ChatChannelHandler
channel *Channel
lastMessageID uint32
}
// ChatChannelHandler is implemented by an application type to receive
// events from a ChatChannel.
//
// Note that ChatChannelHandler is composable with other interfaces, including
// ConnectionHandler; there is no need to use a distinct type as a
// ChatChannelHandler.
type ChatChannelHandler interface {
// ChatMessage is called when a chat message is received. Return true to acknowledge
// the message successfully, and false to NACK and refuse the message.
ChatMessage(messageID uint32, when time.Time, message string) bool
// ChatMessageAck is called when an acknowledgement of a sent message is received.
ChatMessageAck(messageID uint32, accepted bool)
}
// SendMessage sends a given message using this channel, and returns the
// messageID, which will be used in ChatMessageAck when the peer acknowledges
// this message.
func (cc *ChatChannel) SendMessage(message string) uint32 {
return cc.SendMessageWithTime(message, time.Now())
}
// SendMessageWithTime is identical to SendMessage, but also sends the provided time.Time
// as a rough timestamp for when this message was originally sent. This should be used
// when retrying or sending queued messages.
func (cc *ChatChannel) SendMessageWithTime(message string, when time.Time) uint32 {
delta := time.Now().Sub(when) / time.Second
messageBuilder := new(utils.MessageBuilder)
messageID := cc.lastMessageID
cc.lastMessageID++
data := messageBuilder.ChatMessage(message, messageID, int64(delta))
cc.channel.SendMessage(data)
return messageID
}
// Acknowledge indicates that the given messageID was received, and whether
// it was accepted.
func (cc *ChatChannel) Acknowledge(messageID uint32, accepted bool) {
messageBuilder := new(utils.MessageBuilder)
cc.channel.SendMessage(messageBuilder.AckChatMessage(messageID, accepted))
}
// Type returns the type string for this channel, e.g. "im.ricochet.chat".
func (cc *ChatChannel) Type() string {
return "im.ricochet.chat"
}
// Closed is called when the channel is closed for any reason.
func (cc *ChatChannel) Closed(err error) {
}
// OnlyClientCanOpen - for chat channels any side can open
func (cc *ChatChannel) OnlyClientCanOpen() bool {
return false
}
// Singleton - for chat channels there can only be one instance per direction
func (cc *ChatChannel) Singleton() bool {
return true
}
// Bidirectional - for chat channels are not bidrectional
func (cc *ChatChannel) Bidirectional() bool {
return false
}
// RequiresAuthentication - chat channels require hidden service auth
func (cc *ChatChannel) RequiresAuthentication() string {
return "im.ricochet.auth.hidden-service"
}
// OpenInbound is the first method called for an inbound channel request.
// If an error is returned, the channel is rejected. If a RawMessage is
// returned, it will be sent as the ChannelResult message.
func (cc *ChatChannel) OpenInbound(channel *Channel, raw *Protocol_Data_Control.OpenChannel) ([]byte, error) {
cc.channel = channel
id, err := rand.Int(rand.Reader, big.NewInt(math.MaxUint32))
if err != nil {
return nil, err
}
cc.lastMessageID = uint32(id.Uint64())
cc.channel.Pending = false
messageBuilder := new(utils.MessageBuilder)
return messageBuilder.AckOpenChannel(channel.ID), nil
}
// OpenOutbound is the first method called for an outbound channel request.
// If an error is returned, the channel is not opened. If a RawMessage is
// returned, it will be sent as the OpenChannel message.
func (cc *ChatChannel) OpenOutbound(channel *Channel) ([]byte, error) {
cc.channel = channel
id, err := rand.Int(rand.Reader, big.NewInt(math.MaxUint32))
if err != nil {
return nil, err
}
cc.lastMessageID = uint32(id.Uint64())
messageBuilder := new(utils.MessageBuilder)
return messageBuilder.OpenChannel(channel.ID, cc.Type()), nil
}
// OpenOutboundResult is called when a response is received for an
// outbound OpenChannel request. If `err` is non-nil, the channel was
// rejected and Closed will be called immediately afterwards. `raw`
// contains the raw protocol message including any extension data.
func (cc *ChatChannel) OpenOutboundResult(err error, crm *Protocol_Data_Control.ChannelResult) {
if err == nil {
if crm.GetOpened() {
cc.channel.Pending = false
}
}
}
// Packet is called for each raw packet received on this channel.
func (cc *ChatChannel) Packet(data []byte) {
if !cc.channel.Pending {
res := new(Protocol_Data_Chat.Packet)
err := proto.Unmarshal(data, res)
if err == nil {
if res.GetChatMessage() != nil {
ack := cc.Handler.ChatMessage(res.GetChatMessage().GetMessageId(), time.Now(), res.GetChatMessage().GetMessageText())
cc.Acknowledge(res.GetChatMessage().GetMessageId(), ack)
} else if ack := res.GetChatAcknowledge(); ack != nil {
cc.Handler.ChatMessageAck(ack.GetMessageId(), ack.GetAccepted())
}
// XXX?
}
}
}