package core import ( "fmt" protocol "github.com/s-rah/go-ricochet" "github.com/special/notricochet/core/utils" "github.com/special/notricochet/rpc" "golang.org/x/net/context" "log" "strconv" "strings" "sync" "time" ) // XXX There is generally a lot of duplication and boilerplate between // Contact, ConfigContact, and rpc.Contact. This should be reduced somehow. type Contact struct { core *Ricochet id int data ConfigContact status ricochet.Contact_Status mutex sync.Mutex events *utils.Publisher connection *protocol.OpenConnection connChannel chan *protocol.OpenConnection connClosedChannel chan struct{} conversation *Conversation } func ContactFromConfig(core *Ricochet, id int, data ConfigContact, events *utils.Publisher) (*Contact, error) { contact := &Contact{ core: core, id: id, data: data, events: events, connChannel: make(chan *protocol.OpenConnection), connClosedChannel: make(chan struct{}), } if id < 0 { return nil, fmt.Errorf("Invalid contact ID '%d'", id) } else if len(data.Hostname) != 22 || !strings.HasSuffix(data.Hostname, ".onion") { return nil, fmt.Errorf("Invalid contact hostname '%s", data.Hostname) } // XXX Should have some global trigger that starts all contact connections // at the right time go contact.contactConnection() return contact, nil } func (c *Contact) Id() int { return c.id } func (c *Contact) Nickname() string { c.mutex.Lock() defer c.mutex.Unlock() return c.data.Nickname } func (c *Contact) Address() string { c.mutex.Lock() defer c.mutex.Unlock() return "ricochet:" + c.data.Hostname[0:16] } func (c *Contact) Hostname() string { c.mutex.Lock() defer c.mutex.Unlock() return c.data.Hostname } func (c *Contact) LastConnected() time.Time { c.mutex.Lock() defer c.mutex.Unlock() time, _ := time.Parse(time.RFC3339, c.data.LastConnected) return time } func (c *Contact) WhenCreated() time.Time { c.mutex.Lock() defer c.mutex.Unlock() time, _ := time.Parse(time.RFC3339, c.data.WhenCreated) return time } func (c *Contact) Status() ricochet.Contact_Status { c.mutex.Lock() defer c.mutex.Unlock() return c.status } func (c *Contact) Data() *ricochet.Contact { c.mutex.Lock() defer c.mutex.Unlock() data := &ricochet.Contact{ Id: int32(c.id), Address: "ricochet:" + c.data.Hostname[0:16], Nickname: c.data.Nickname, WhenCreated: c.data.WhenCreated, LastConnected: c.data.LastConnected, Status: c.status, } return data } func (c *Contact) Conversation() *Conversation { c.mutex.Lock() defer c.mutex.Unlock() if c.conversation == nil { entity := &ricochet.Entity{ ContactId: int32(c.id), Address: "ricochet:" + c.data.Hostname[0:16], } c.conversation = NewConversation(c.core, c, entity) } return c.conversation } // XXX Thread safety disaster func (c *Contact) Connection() *protocol.OpenConnection { c.mutex.Lock() defer c.mutex.Unlock() return c.connection } // Goroutine to handle the protocol connection for a contact. // Responsible for making outbound connections and taking over authenticated // inbound connections, running protocol handlers on the active connection, and // reacting to connection loss. Nothing else may write Contact.connection. func (c *Contact) contactConnection() { // XXX Should the protocol continue handling its own goroutines? // I'm thinking the protocol API design I want is: // - "handler" assigned per-connection // - each inbound listener has its own handler also, assigns for conns // - so, non-authed connection has a handler that _can't_ do anything other than auth // - inbound contact req connection gets a special handler for that case // - authenticated contact conns get handler changed here // It's probably more sensible to never break the conn read loop, because of buffering etc // So likely we don't want to change that goroutine. Could still use a channel to pass it // to handler for parsing, which could let it go on any goroutine we want, if it's desirable // to put it on e.g. this routine. Hmm. for { // If there is no active connection, spawn an outbound connector. // A successful connection is returned via connChannel; otherwise, it will keep trying. var outboundCtx context.Context outboundCancel := func() {} if c.connection == nil { outboundCtx, outboundCancel = context.WithCancel(context.Background()) go c.connectOutbound(outboundCtx, c.connChannel) } select { case conn, ok := <-c.connChannel: outboundCancel() if !ok { // Closing connChannel exits this connection routine, for contact // deletion, exit, or some other case. break } else if conn == nil { // Signal used to restart outbound connection attempts continue } // Received a new connection. The connection is already authenticated and ready to use. // This connection may be inbound or outbound. setConnection will decide whether to // replace an existing connection. // XXX Tweak setConnection logic if needed // Logic when keeping connection, need to make sure protocol is going, etc... if err := c.setConnection(conn); err != nil { log.Printf("Discarded new contact %s connection: %s", c.Address(), err) if !conn.Closed && conn != c.connection { conn.Close() } continue } case <-c.connClosedChannel: outboundCancel() c.clearConnection(nil) } } log.Printf("Exiting contact connection loop for %s", c.Address()) c.clearConnection(nil) } // Attempt an outbound connection to the contact, retrying automatically using OnionConnector. // This function _must_ send something to connChannel before returning, unless the context has // been cancelled. func (c *Contact) connectOutbound(ctx context.Context, connChannel chan *protocol.OpenConnection) { c.mutex.Lock() connector := OnionConnector{ Network: c.core.Network, NeverGiveUp: true, } hostname := c.data.Hostname c.mutex.Unlock() for { conn, err := connector.Connect(hostname+":9878", ctx) if err != nil { // The only failure here should be context, because NeverGiveUp // is set, but be robust anyway. if ctx.Err() != nil { return } log.Printf("Contact connection failure: %s", err) continue } log.Printf("Successful outbound connection to contact %s", hostname) oc, err := c.core.Protocol.ConnectOpen(conn, hostname[0:16]) if err != nil { log.Printf("Contact connection protocol failure: %s", err) oc.Close() // XXX These failures are probably not worth retrying so much, // but that would need to be investigated. For now, just do the // same backoff behavior. if err := connector.Backoff(ctx); err != nil { return } continue } else { log.Printf("Protocol connection open: %v", oc) // XXX Protocol API needs to be reworked; see notes in // contactConnection. Ideally we should authenticate here and // pass the conneciton back, but for now this can do nothing: // the connection will either succeed and come in via the // protocol handler, or will be closed and signalled via // OnConnectionClosed. Alternatively, it will break because this // is fragile and dumb. // XXX BUG: This means no backoff for authentication failure return } } } func (c *Contact) setConnection(conn *protocol.OpenConnection) error { if conn.Client { log.Printf("Contact %s has a new outbound connection", c.Address()) } else { log.Printf("Contact %s has a new inbound connection", c.Address()) } c.mutex.Lock() if conn == c.connection { c.mutex.Unlock() return fmt.Errorf("Duplicate assignment of connection %v to contact %v", conn, c) } if !conn.IsAuthed || conn.Closed { c.mutex.Unlock() conn.Close() return fmt.Errorf("Connection %v is not in a valid state to assign to contact %v", conn, c) } if c.data.Hostname[0:16] != conn.OtherHostname { c.mutex.Unlock() conn.Close() return fmt.Errorf("Connection hostname %s doesn't match contact hostname %s when assigning connection", conn.OtherHostname, c.data.Hostname[0:16]) } if c.connection != nil { if c.shouldReplaceConnection(conn) { // XXX Signal state change for connection loss? c.connection.Close() c.connection = nil } else { c.mutex.Unlock() conn.Close() return fmt.Errorf("Using existing connection") } } // If this connection is inbound and there's an outbound attempt, keep this // connection and cancel outbound if we haven't sent authentication yet, or // if the outbound connection will lose the fallback comparison above. // XXX implement this c.connection = conn c.status = ricochet.Contact_ONLINE log.Printf("Assigned connection %v to contact %v", c.connection, c) // XXX implicit accept contact requests // Update LastConnected time config := c.core.Config.OpenWrite() c.data.LastConnected = time.Now().Format(time.RFC3339) config.Contacts[strconv.Itoa(c.id)] = c.data config.Save() c.mutex.Unlock() event := ricochet.ContactEvent{ Type: ricochet.ContactEvent_UPDATE, Subject: &ricochet.ContactEvent_Contact{ Contact: c.Data(), }, } c.events.Publish(event) return nil } // Close and clear state related to the active contact connection. // If ifConn is non-nil, the active connection is only cleared if // it is the same as ifConn. Returns true if cleared. func (c *Contact) clearConnection(ifConn *protocol.OpenConnection) bool { c.mutex.Lock() if c.connection == nil || (ifConn != nil && c.connection != ifConn) { c.mutex.Unlock() return false } conn := c.connection c.connection = nil c.status = ricochet.Contact_OFFLINE // XXX eww, and also potentially deadlockable? config := c.core.Config.OpenWrite() c.data.LastConnected = time.Now().Format(time.RFC3339) config.Contacts[strconv.Itoa(c.id)] = c.data config.Save() c.mutex.Unlock() if conn != nil && !conn.Closed { conn.Close() } event := ricochet.ContactEvent{ Type: ricochet.ContactEvent_UPDATE, Subject: &ricochet.ContactEvent_Contact{ Contact: c.Data(), }, } c.events.Publish(event) return true } // Decide whether to replace the existing connection with conn. // Assumes mutex is held. func (c *Contact) shouldReplaceConnection(conn *protocol.OpenConnection) bool { if c.connection == nil { return true } else if c.connection.Closed { log.Printf("Replacing dead connection %v for contact %v", c.connection, c) return true } else if c.connection.Client == conn.Client { // If the existing connection is in the same direction, always use the new one log.Printf("Replacing existing same-direction connection %v with new connection %v for contact %v", c.connection, conn, c) return true } else if false { // If the existing connection is more than 30 seconds old, use the new one // XXX implement this } else if preferOutbound := conn.MyHostname < conn.OtherHostname; preferOutbound == conn.Client { // Fall back to string comparison of hostnames for a stable resolution // New connection wins log.Printf("Replacing existing connection %v with new connection %v for contact %v according to fallback order", c.connection, conn, c) return true } else { // Old connection wins fallback log.Printf("Keeping existing connection %v instead of new connection %v for contact %v according to fallback order", c.connection, conn, c) return false } return false } // XXX also will go away during protocol API rework func (c *Contact) OnConnectionAuthenticated(conn *protocol.OpenConnection) { c.connChannel <- conn } // XXX rework connection close to have a proper notification instead of this "find contact" mess. func (c *Contact) OnConnectionClosed(conn *protocol.OpenConnection) { c.mutex.Lock() if c.connection != conn { c.mutex.Unlock() return } c.mutex.Unlock() c.connClosedChannel <- struct{}{} }