source: code/trunk/user.go@ 403

package soju

import (
        "crypto/sha256"
        "encoding/binary"
        "encoding/hex"
        "fmt"
        "time"

        "gopkg.in/irc.v3"
)

type event interface{}

type eventUpstreamMessage struct {
        msg *irc.Message
        uc  *upstreamConn
}

type eventUpstreamConnectionError struct {
        net *network
        err error
}

type eventUpstreamConnected struct {
        uc *upstreamConn
}

type eventUpstreamDisconnected struct {
        uc *upstreamConn
}

type eventUpstreamError struct {
        uc  *upstreamConn
        err error
}

type eventDownstreamMessage struct {
        msg *irc.Message
        dc  *downstreamConn
}

type eventDownstreamConnected struct {
        dc *downstreamConn
}

type eventDownstreamDisconnected struct {
        dc *downstreamConn
}

type eventStop struct{}

type networkHistory struct {
        offlineClients map[string]uint64 // indexed by client name
        ring           *Ring             // can be nil if there are no offline clients
}

type network struct {
        Network
        user    *user
        stopped chan struct{}

        conn           *upstreamConn
        channels       map[string]*Channel
        history        map[string]*networkHistory // indexed by entity
        offlineClients map[string]struct{}        // indexed by client name
        lastError      error
}

func newNetwork(user *user, record *Network, channels []Channel) *network {
        m := make(map[string]*Channel, len(channels))
        for _, ch := range channels {
                ch := ch
                m[ch.Name] = &ch
        }

        return &network{
                Network:        *record,
                user:           user,
                stopped:        make(chan struct{}),
                channels:       m,
                history:        make(map[string]*networkHistory),
                offlineClients: make(map[string]struct{}),
        }
}

func (net *network) forEachDownstream(f func(*downstreamConn)) {
        net.user.forEachDownstream(func(dc *downstreamConn) {
                if dc.network != nil && dc.network != net {
                        return
                }
                f(dc)
        })
}

func (net *network) isStopped() bool {
        select {
        case <-net.stopped:
                return true
        default:
                return false
        }
}

func userIdent(u *User) string {
        // The ident is a string we will send to upstream servers in clear-text.
        // For privacy reasons, make sure it doesn't expose any meaningful user
        // metadata. We just use the base64-encoded hashed ID, so that people don't
        // start relying on the string being an integer or following a pattern.
        var b [64]byte
        binary.LittleEndian.PutUint64(b[:], uint64(u.ID))
        h := sha256.Sum256(b[:])
        return hex.EncodeToString(h[:16])
}

func (net *network) run() {
        var lastTry time.Time
        for {
                if net.isStopped() {
                        return
                }

                if dur := time.Now().Sub(lastTry); dur < retryConnectDelay {
                        delay := retryConnectDelay - dur
                        net.user.srv.Logger.Printf("waiting %v before trying to reconnect to %q", delay.Truncate(time.Second), net.Addr)
                        time.Sleep(delay)
                }
                lastTry = time.Now()

                uc, err := connectToUpstream(net)
                if err != nil {
                        net.user.srv.Logger.Printf("failed to connect to upstream server %q: %v", net.Addr, err)
                        net.user.events <- eventUpstreamConnectionError{net, fmt.Errorf("failed to connect: %v", err)}
                        continue
                }

                if net.user.srv.Identd != nil {
                        net.user.srv.Identd.Store(uc.RemoteAddr().String(), uc.LocalAddr().String(), userIdent(&net.user.User))
                }

                uc.register()
                if err := uc.runUntilRegistered(); err != nil {
                        text := err.Error()
                        if regErr, ok := err.(registrationError); ok {
                                text = string(regErr)
                        }
                        uc.logger.Printf("failed to register: %v", text)
                        net.user.events <- eventUpstreamConnectionError{net, fmt.Errorf("failed to register: %v", text)}
                        uc.Close()
                        continue
                }

                // TODO: this is racy with net.stopped. If the network is stopped
                // before the user goroutine receives eventUpstreamConnected, the
                // connection won't be closed.
                net.user.events <- eventUpstreamConnected{uc}
                if err := uc.readMessages(net.user.events); err != nil {
                        uc.logger.Printf("failed to handle messages: %v", err)
                        net.user.events <- eventUpstreamError{uc, fmt.Errorf("failed to handle messages: %v", err)}
                }
                uc.Close()
                net.user.events <- eventUpstreamDisconnected{uc}

                if net.user.srv.Identd != nil {
                        net.user.srv.Identd.Delete(uc.RemoteAddr().String(), uc.LocalAddr().String())
                }
        }
}

func (net *network) stop() {
        if !net.isStopped() {
                close(net.stopped)
        }

        if net.conn != nil {
                net.conn.Close()
        }
}

func (net *network) createUpdateChannel(ch *Channel) error {
        if current, ok := net.channels[ch.Name]; ok {
                ch.ID = current.ID // update channel if it already exists
        }
        if err := net.user.srv.db.StoreChannel(net.ID, ch); err != nil {
                return err
        }
        prev := net.channels[ch.Name]
        net.channels[ch.Name] = ch

        if prev != nil && prev.Detached != ch.Detached {
                history := net.history[ch.Name]
                if ch.Detached {
                        net.user.srv.Logger.Printf("network %q: detaching channel %q", net.GetName(), ch.Name)
                        net.forEachDownstream(func(dc *downstreamConn) {
                                net.offlineClients[dc.clientName] = struct{}{}
                                if history != nil {
                                        history.offlineClients[dc.clientName] = history.ring.Cur()
                                }

                                dc.SendMessage(&irc.Message{
                                        Prefix:  dc.prefix(),
                                        Command: "PART",
                                        Params:  []string{dc.marshalEntity(net, ch.Name), "Detach"},
                                })
                        })
                } else {
                        net.user.srv.Logger.Printf("network %q: attaching channel %q", net.GetName(), ch.Name)

                        var uch *upstreamChannel
                        if net.conn != nil {
                                uch = net.conn.channels[ch.Name]
                        }

                        net.forEachDownstream(func(dc *downstreamConn) {
                                dc.SendMessage(&irc.Message{
                                        Prefix:  dc.prefix(),
                                        Command: "JOIN",
                                        Params:  []string{dc.marshalEntity(net, ch.Name)},
                                })

                                if uch != nil {
                                        forwardChannel(dc, uch)
                                }

                                if history != nil {
                                        dc.sendNetworkHistory(net)
                                }
                        })
                }
        }

        return nil
}

func (net *network) deleteChannel(name string) error {
        if err := net.user.srv.db.DeleteChannel(net.ID, name); err != nil {
                return err
        }
        delete(net.channels, name)
        return nil
}

type user struct {
        User
        srv *Server

        events chan event
        done   chan struct{}

        networks        []*network
        downstreamConns []*downstreamConn

        // LIST commands in progress
        pendingLISTs []pendingLIST
}

type pendingLIST struct {
        downstreamID uint64
        // list of per-upstream LIST commands not yet sent or completed
        pendingCommands map[int64]*irc.Message
}

func newUser(srv *Server, record *User) *user {
        return &user{
                User:   *record,
                srv:    srv,
                events: make(chan event, 64),
                done:   make(chan struct{}),
        }
}

func (u *user) forEachNetwork(f func(*network)) {
        for _, network := range u.networks {
                f(network)
        }
}

func (u *user) forEachUpstream(f func(uc *upstreamConn)) {
        for _, network := range u.networks {
                if network.conn == nil {
                        continue
                }
                f(network.conn)
        }
}

func (u *user) forEachDownstream(f func(dc *downstreamConn)) {
        for _, dc := range u.downstreamConns {
                f(dc)
        }
}

func (u *user) getNetwork(name string) *network {
        for _, network := range u.networks {
                if network.Addr == name {
                        return network
                }
                if network.Name != "" && network.Name == name {
                        return network
                }
        }
        return nil
}

func (u *user) getNetworkByID(id int64) *network {
        for _, net := range u.networks {
                if net.ID == id {
                        return net
                }
        }
        return nil
}

func (u *user) run() {
        defer close(u.done)

        networks, err := u.srv.db.ListNetworks(u.Username)
        if err != nil {
                u.srv.Logger.Printf("failed to list networks for user %q: %v", u.Username, err)
                return
        }

        for _, record := range networks {
                record := record
                channels, err := u.srv.db.ListChannels(record.ID)
                if err != nil {
                        u.srv.Logger.Printf("failed to list channels for user %q, network %q: %v", u.Username, record.GetName(), err)
                        continue
                }

                network := newNetwork(u, &record, channels)
                u.networks = append(u.networks, network)

                go network.run()
        }

        for e := range u.events {
                switch e := e.(type) {
                case eventUpstreamConnected:
                        uc := e.uc

                        uc.network.conn = uc

                        uc.updateAway()

                        uc.forEachDownstream(func(dc *downstreamConn) {
                                dc.updateSupportedCaps()
                                sendServiceNOTICE(dc, fmt.Sprintf("connected to %s", uc.network.GetName()))

                                dc.updateNick()
                        })
                        uc.network.lastError = nil
                case eventUpstreamDisconnected:
                        u.handleUpstreamDisconnected(e.uc)
                case eventUpstreamConnectionError:
                        net := e.net

                        stopped := false
                        select {
                        case <-net.stopped:
                                stopped = true
                        default:
                        }

                        if !stopped && (net.lastError == nil || net.lastError.Error() != e.err.Error()) {
                                net.forEachDownstream(func(dc *downstreamConn) {
                                        sendServiceNOTICE(dc, fmt.Sprintf("failed connecting/registering to %s: %v", net.GetName(), e.err))
                                })
                        }
                        net.lastError = e.err
                case eventUpstreamError:
                        uc := e.uc

                        uc.forEachDownstream(func(dc *downstreamConn) {
                                sendServiceNOTICE(dc, fmt.Sprintf("disconnected from %s: %v", uc.network.GetName(), e.err))
                        })
                        uc.network.lastError = e.err
                case eventUpstreamMessage:
                        msg, uc := e.msg, e.uc
                        if uc.isClosed() {
                                uc.logger.Printf("ignoring message on closed connection: %v", msg)
                                break
                        }
                        if err := uc.handleMessage(msg); err != nil {
                                uc.logger.Printf("failed to handle message %q: %v", msg, err)
                        }
                case eventDownstreamConnected:
                        dc := e.dc

                        if err := dc.welcome(); err != nil {
                                dc.logger.Printf("failed to handle new registered connection: %v", err)
                                break
                        }

                        u.downstreamConns = append(u.downstreamConns, dc)

                        u.forEachUpstream(func(uc *upstreamConn) {
                                uc.updateAway()
                        })

                        dc.updateSupportedCaps()
                case eventDownstreamDisconnected:
                        dc := e.dc

                        for i := range u.downstreamConns {
                                if u.downstreamConns[i] == dc {
                                        u.downstreamConns = append(u.downstreamConns[:i], u.downstreamConns[i+1:]...)
                                        break
                                }
                        }

                        // Save history if we're the last client with this name
                        skipHistory := make(map[*network]bool)
                        u.forEachDownstream(func(conn *downstreamConn) {
                                if dc.clientName == conn.clientName {
                                        skipHistory[conn.network] = true
                                }
                        })

                        dc.forEachNetwork(func(net *network) {
                                if skipHistory[net] || skipHistory[nil] {
                                        return
                                }

                                net.offlineClients[dc.clientName] = struct{}{}
                                for target, history := range net.history {
                                        if ch, ok := net.channels[target]; ok && ch.Detached {
                                                continue
                                        }
                                        history.offlineClients[dc.clientName] = history.ring.Cur()
                                }
                        })

                        u.forEachUpstream(func(uc *upstreamConn) {
                                uc.updateAway()
                        })
                case eventDownstreamMessage:
                        msg, dc := e.msg, e.dc
                        if dc.isClosed() {
                                dc.logger.Printf("ignoring message on closed connection: %v", msg)
                                break
                        }
                        err := dc.handleMessage(msg)
                        if ircErr, ok := err.(ircError); ok {
                                ircErr.Message.Prefix = dc.srv.prefix()
                                dc.SendMessage(ircErr.Message)
                        } else if err != nil {
                                dc.logger.Printf("failed to handle message %q: %v", msg, err)
                                dc.Close()
                        }
                case eventStop:
                        u.forEachDownstream(func(dc *downstreamConn) {
                                dc.Close()
                        })
                        for _, n := range u.networks {
                                n.stop()
                        }
                        return
                default:
                        u.srv.Logger.Printf("received unknown event type: %T", e)
                }
        }
}

func (u *user) handleUpstreamDisconnected(uc *upstreamConn) {
        uc.network.conn = nil

        for _, ml := range uc.messageLoggers {
                if err := ml.Close(); err != nil {
                        uc.logger.Printf("failed to close message logger: %v", err)
                }
        }

        uc.endPendingLISTs(true)

        uc.forEachDownstream(func(dc *downstreamConn) {
                dc.updateSupportedCaps()
        })

        if uc.network.lastError == nil {
                uc.forEachDownstream(func(dc *downstreamConn) {
                        sendServiceNOTICE(dc, fmt.Sprintf("disconnected from %s", uc.network.GetName()))
                })
        }
}

func (u *user) addNetwork(network *network) {
        u.networks = append(u.networks, network)
        go network.run()
}

func (u *user) removeNetwork(network *network) {
        network.stop()

        u.forEachDownstream(func(dc *downstreamConn) {
                if dc.network != nil && dc.network == network {
                        dc.Close()
                }
        })

        for i, net := range u.networks {
                if net == network {
                        u.networks = append(u.networks[:i], u.networks[i+1:]...)
                        return
                }
        }

        panic("tried to remove a non-existing network")
}

func (u *user) createNetwork(record *Network) (*network, error) {
        if record.ID != 0 {
                panic("tried creating an already-existing network")
        }

        network := newNetwork(u, record, nil)
        err := u.srv.db.StoreNetwork(u.Username, &network.Network)
        if err != nil {
                return nil, err
        }

        u.addNetwork(network)

        return network, nil
}

func (u *user) updateNetwork(record *Network) (*network, error) {
        if record.ID == 0 {
                panic("tried updating a new network")
        }

        network := u.getNetworkByID(record.ID)
        if network == nil {
                panic("tried updating a non-existing network")
        }

        if err := u.srv.db.StoreNetwork(u.Username, record); err != nil {
                return nil, err
        }

        // Most network changes require us to re-connect to the upstream server

        channels := make([]Channel, 0, len(network.channels))
        for _, ch := range network.channels {
                channels = append(channels, *ch)
        }

        updatedNetwork := newNetwork(u, record, channels)

        // If we're currently connected, disconnect and perform the necessary
        // bookkeeping
        if network.conn != nil {
                network.stop()
                // Note: this will set network.conn to nil
                u.handleUpstreamDisconnected(network.conn)
        }

        // Patch downstream connections to use our fresh updated network
        u.forEachDownstream(func(dc *downstreamConn) {
                if dc.network != nil && dc.network == network {
                        dc.network = updatedNetwork
                }
        })

        // We need to remove the network after patching downstream connections,
        // otherwise they'll get closed
        u.removeNetwork(network)

        // This will re-connect to the upstream server
        u.addNetwork(updatedNetwork)

        return updatedNetwork, nil
}

func (u *user) deleteNetwork(id int64) error {
        network := u.getNetworkByID(id)
        if network == nil {
                panic("tried deleting a non-existing network")
        }

        if err := u.srv.db.DeleteNetwork(network.ID); err != nil {
                return err
        }

        u.removeNetwork(network)
        return nil
}

func (u *user) updatePassword(hashed string) error {
        u.User.Password = hashed
        return u.srv.db.StoreUser(&u.User)
}

func (u *user) stop() {
        u.events <- eventStop{}
        <-u.done
}