cwtch/protocol/connections/peerapp.go

package connections

import (
	model2 "cwtch.im/cwtch/protocol/model"
	"encoding/json"
	"git.openprivacy.ca/cwtch.im/tapir"
	"git.openprivacy.ca/cwtch.im/tapir/applications"
	"git.openprivacy.ca/openprivacy/log"
)

const cwtchCapability = tapir.Capability("cwtchCapability")

// PeerApp encapsulates the behaviour of a Cwtch Peer
type PeerApp struct {
	applications.AuthApp
	connection        tapir.Connection
	MessageHandler    func(string, string, string, []byte)
	IsBlocked         func(string) bool
	IsAllowed         func(string) bool
	OnAcknowledgement func(string, string)
	OnAuth            func(string)
	OnClose           func(string)
	OnConnecting      func(string)
}

type peerGetVal struct {
	Scope, Path string
}

type peerRetVal struct {
	Val    string
	Exists bool
}

// NewInstance should always return a new instantiation of the application.
func (pa *PeerApp) NewInstance() tapir.Application {
	newApp := new(PeerApp)
	newApp.MessageHandler = pa.MessageHandler
	newApp.IsBlocked = pa.IsBlocked
	newApp.IsAllowed = pa.IsAllowed
	newApp.OnAcknowledgement = pa.OnAcknowledgement
	newApp.OnAuth = pa.OnAuth
	newApp.OnClose = pa.OnClose
	newApp.OnConnecting = pa.OnConnecting
	return newApp
}

// Init is run when the connection is first started.
func (pa *PeerApp) Init(connection tapir.Connection) {
	// First run the Authentication App
	pa.AuthApp.Init(connection)

	if connection.HasCapability(applications.AuthCapability) {

		pa.connection = connection
		connection.SetCapability(cwtchCapability)

		if pa.IsBlocked(connection.Hostname()) {
			pa.connection.Close()
			pa.OnClose(connection.Hostname())
		} else {
			pa.OnAuth(connection.Hostname())
			go pa.listen()
		}
	} else {
		// The auth protocol wasn't completed, we can safely shutdown the connection
		connection.Close()
	}
}

func (pa *PeerApp) listen() {
	for {
		message := pa.connection.Expect()
		if len(message) == 0 {
			log.Debugf("0 byte read, socket has likely failed. Closing the listen goroutine")
			pa.OnClose(pa.connection.Hostname())
			return
		}
		var peerMessage model2.PeerMessage
		err := json.Unmarshal(message, &peerMessage)
		if err == nil {
			if pa.IsAllowed(pa.connection.Hostname()) {
				pa.MessageHandler(pa.connection.Hostname(), peerMessage.ID, peerMessage.Context, peerMessage.Data)
			}
		} else {
			log.Errorf("Error unmarshalling PeerMessage package: %x %v", message, err)
		}
	}
}

// SendMessage sends the peer a preformatted message
// NOTE: This is a stub, we will likely want to extend this to better reflect the desired protocol
func (pa *PeerApp) SendMessage(message model2.PeerMessage) error {
	serialized, err := json.Marshal(message)
	if err == nil {
		return pa.connection.Send(serialized)
	}
	return err
}