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- // Copyright (c) 2017 Shivaram Lingamneni <slingamn@cs.stanford.edu>
- // released under the MIT license
-
- package irc
-
- import (
- "sync"
-
- "github.com/oragono/oragono/irc/utils"
- )
-
- type channelManagerEntry struct {
- channel *Channel
- // this is a refcount for joins, so we can avoid a race where we incorrectly
- // think the channel is empty (without holding a lock across the entire Channel.Join()
- // call)
- pendingJoins int
- skeleton string
- }
-
- // ChannelManager keeps track of all the channels on the server,
- // providing synchronization for creation of new channels on first join,
- // cleanup of empty channels on last part, and renames.
- type ChannelManager struct {
- sync.RWMutex // tier 2
- // chans is the main data structure, mapping casefolded name -> *Channel
- chans map[string]*channelManagerEntry
- chansSkeletons utils.StringSet // skeletons of *unregistered* chans
- registeredChannels utils.StringSet // casefolds of registered chans
- registeredSkeletons utils.StringSet // skeletons of registered chans
- purgedChannels utils.StringSet // casefolds of purged chans
- server *Server
- }
-
- // NewChannelManager returns a new ChannelManager.
- func (cm *ChannelManager) Initialize(server *Server) {
- cm.chans = make(map[string]*channelManagerEntry)
- cm.chansSkeletons = make(utils.StringSet)
- cm.server = server
-
- cm.loadRegisteredChannels(server.Config())
- // purging should work even if registration is disabled
- cm.purgedChannels = cm.server.channelRegistry.PurgedChannels()
- }
-
- func (cm *ChannelManager) loadRegisteredChannels(config *Config) {
- if !config.Channels.Registration.Enabled {
- return
- }
-
- rawNames := cm.server.channelRegistry.AllChannels()
- registeredChannels := make(utils.StringSet, len(rawNames))
- registeredSkeletons := make(utils.StringSet, len(rawNames))
- for _, name := range rawNames {
- cfname, err := CasefoldChannel(name)
- if err == nil {
- registeredChannels.Add(cfname)
- }
- skeleton, err := Skeleton(name)
- if err == nil {
- registeredSkeletons.Add(skeleton)
- }
- }
- cm.Lock()
- defer cm.Unlock()
- cm.registeredChannels = registeredChannels
- cm.registeredSkeletons = registeredSkeletons
- }
-
- // Get returns an existing channel with name equivalent to `name`, or nil
- func (cm *ChannelManager) Get(name string) (channel *Channel) {
- name, err := CasefoldChannel(name)
- if err == nil {
- cm.RLock()
- defer cm.RUnlock()
- entry := cm.chans[name]
- // if the channel is still loading, pretend we don't have it
- if entry != nil && entry.channel.IsLoaded() {
- return entry.channel
- }
- }
- return nil
- }
-
- // Join causes `client` to join the channel named `name`, creating it if necessary.
- func (cm *ChannelManager) Join(client *Client, name string, key string, isSajoin bool, rb *ResponseBuffer) error {
- server := client.server
- casefoldedName, err := CasefoldChannel(name)
- skeleton, skerr := Skeleton(name)
- if err != nil || skerr != nil || len(casefoldedName) > server.Config().Limits.ChannelLen {
- return errNoSuchChannel
- }
-
- channel, err := func() (*Channel, error) {
- cm.Lock()
- defer cm.Unlock()
-
- if cm.purgedChannels.Has(casefoldedName) {
- return nil, errChannelPurged
- }
- entry := cm.chans[casefoldedName]
- if entry == nil {
- registered := cm.registeredChannels.Has(casefoldedName)
- // enforce OpOnlyCreation
- if !registered && server.Config().Channels.OpOnlyCreation && !client.HasRoleCapabs("chanreg") {
- return nil, errInsufficientPrivs
- }
- // enforce confusables
- if cm.chansSkeletons.Has(skeleton) || (!registered && cm.registeredSkeletons.Has(skeleton)) {
- return nil, errConfusableIdentifier
- }
- entry = &channelManagerEntry{
- channel: NewChannel(server, name, casefoldedName, registered),
- pendingJoins: 0,
- }
- if !registered {
- // for an unregistered channel, we already have the correct unfolded name
- // and therefore the final skeleton. for a registered channel, we don't have
- // the unfolded name yet (it needs to be loaded from the db), but we already
- // have the final skeleton in `registeredSkeletons` so we don't need to track it
- cm.chansSkeletons.Add(skeleton)
- entry.skeleton = skeleton
- }
- cm.chans[casefoldedName] = entry
- }
- entry.pendingJoins += 1
- return entry.channel, nil
- }()
-
- if err != nil {
- return err
- }
-
- channel.EnsureLoaded()
- err = channel.Join(client, key, isSajoin, rb)
-
- cm.maybeCleanup(channel, true)
-
- return err
- }
-
- func (cm *ChannelManager) maybeCleanup(channel *Channel, afterJoin bool) {
- cm.Lock()
- defer cm.Unlock()
-
- cfname := channel.NameCasefolded()
-
- entry := cm.chans[cfname]
- if entry == nil || entry.channel != channel {
- return
- }
-
- if afterJoin {
- entry.pendingJoins -= 1
- }
- if entry.pendingJoins == 0 && entry.channel.IsClean() {
- delete(cm.chans, cfname)
- if entry.skeleton != "" {
- delete(cm.chansSkeletons, entry.skeleton)
- }
- }
- }
-
- // Part parts `client` from the channel named `name`, deleting it if it's empty.
- func (cm *ChannelManager) Part(client *Client, name string, message string, rb *ResponseBuffer) error {
- var channel *Channel
-
- casefoldedName, err := CasefoldChannel(name)
- if err != nil {
- return errNoSuchChannel
- }
-
- cm.RLock()
- entry := cm.chans[casefoldedName]
- if entry != nil {
- channel = entry.channel
- }
- cm.RUnlock()
-
- if channel == nil {
- return errNoSuchChannel
- }
- channel.Part(client, message, rb)
- return nil
- }
-
- func (cm *ChannelManager) Cleanup(channel *Channel) {
- cm.maybeCleanup(channel, false)
- }
-
- func (cm *ChannelManager) SetRegistered(channelName string, account string) (err error) {
- if cm.server.Defcon() <= 4 {
- return errFeatureDisabled
- }
-
- var channel *Channel
- cfname, err := CasefoldChannel(channelName)
- if err != nil {
- return err
- }
-
- var entry *channelManagerEntry
-
- defer func() {
- if err == nil && channel != nil {
- // registration was successful: make the database reflect it
- err = channel.Store(IncludeAllAttrs)
- }
- }()
-
- cm.Lock()
- defer cm.Unlock()
- entry = cm.chans[cfname]
- if entry == nil {
- return errNoSuchChannel
- }
- channel = entry.channel
- err = channel.SetRegistered(account)
- if err != nil {
- return err
- }
- cm.registeredChannels.Add(cfname)
- if skel, err := Skeleton(channel.Name()); err == nil {
- cm.registeredSkeletons.Add(skel)
- }
- return nil
- }
-
- func (cm *ChannelManager) SetUnregistered(channelName string, account string) (err error) {
- cfname, err := CasefoldChannel(channelName)
- if err != nil {
- return err
- }
-
- info, err := cm.server.channelRegistry.LoadChannel(cfname)
- if err != nil {
- return err
- }
- if info.Founder != account {
- return errChannelNotOwnedByAccount
- }
-
- defer func() {
- if err == nil {
- err = cm.server.channelRegistry.Delete(info)
- }
- }()
-
- cm.Lock()
- defer cm.Unlock()
- entry := cm.chans[cfname]
- if entry != nil {
- entry.channel.SetUnregistered(account)
- delete(cm.registeredChannels, cfname)
- if skel, err := Skeleton(entry.channel.Name()); err == nil {
- delete(cm.registeredSkeletons, skel)
- }
- }
- return nil
- }
-
- // Rename renames a channel (but does not notify the members)
- func (cm *ChannelManager) Rename(name string, newName string) (err error) {
- cfname, err := CasefoldChannel(name)
- if err != nil {
- return errNoSuchChannel
- }
-
- newCfname, err := CasefoldChannel(newName)
- if err != nil {
- return errInvalidChannelName
- }
- newSkeleton, err := Skeleton(newName)
- if err != nil {
- return errInvalidChannelName
- }
-
- var channel *Channel
- var info RegisteredChannel
- defer func() {
- if channel != nil && info.Founder != "" {
- channel.Store(IncludeAllAttrs)
- // we just flushed the channel under its new name, therefore this delete
- // cannot be overwritten by a write to the old name:
- cm.server.channelRegistry.Delete(info)
- }
- }()
-
- cm.Lock()
- defer cm.Unlock()
-
- if newCfname == cfname {
- entry := cm.chans[cfname]
- if entry == nil || !entry.channel.IsLoaded() {
- return errNoSuchChannel
- }
- entry.channel.Rename(newName, cfname)
- return nil
- }
- if cm.chans[newCfname] != nil || cm.registeredChannels.Has(newCfname) {
- return errChannelNameInUse
- }
- if cm.chansSkeletons.Has(newSkeleton) || cm.registeredSkeletons.Has(newSkeleton) {
- return errChannelNameInUse
- }
- entry := cm.chans[cfname]
- if entry == nil || !entry.channel.IsLoaded() {
- return errNoSuchChannel
- }
- channel = entry.channel
- info = channel.ExportRegistration(IncludeInitial)
- registered := info.Founder != ""
- delete(cm.chans, cfname)
- cm.chans[newCfname] = entry
- if registered {
- delete(cm.registeredChannels, cfname)
- if oldSkeleton, err := Skeleton(info.Name); err == nil {
- delete(cm.registeredSkeletons, oldSkeleton)
- }
- cm.registeredChannels.Add(newCfname)
- cm.registeredSkeletons.Add(newSkeleton)
- } else {
- delete(cm.chansSkeletons, entry.skeleton)
- cm.chansSkeletons.Add(newSkeleton)
- entry.skeleton = newSkeleton
- cm.chans[cfname] = entry
- }
- entry.channel.Rename(newName, newCfname)
- return nil
- }
-
- // Len returns the number of channels
- func (cm *ChannelManager) Len() int {
- cm.RLock()
- defer cm.RUnlock()
- return len(cm.chans)
- }
-
- // Channels returns a slice containing all current channels
- func (cm *ChannelManager) Channels() (result []*Channel) {
- cm.RLock()
- defer cm.RUnlock()
- result = make([]*Channel, 0, len(cm.chans))
- for _, entry := range cm.chans {
- if entry.channel.IsLoaded() {
- result = append(result, entry.channel)
- }
- }
- return
- }
-
- // Purge marks a channel as purged.
- func (cm *ChannelManager) Purge(chname string, record ChannelPurgeRecord) (err error) {
- chname, err = CasefoldChannel(chname)
- if err != nil {
- return errInvalidChannelName
- }
-
- cm.Lock()
- cm.purgedChannels.Add(chname)
- cm.Unlock()
-
- cm.server.channelRegistry.PurgeChannel(chname, record)
- return nil
- }
-
- // IsPurged queries whether a channel is purged.
- func (cm *ChannelManager) IsPurged(chname string) (result bool) {
- chname, err := CasefoldChannel(chname)
- if err != nil {
- return false
- }
-
- cm.RLock()
- result = cm.purgedChannels.Has(chname)
- cm.RUnlock()
- return
- }
-
- // Unpurge deletes a channel's purged status.
- func (cm *ChannelManager) Unpurge(chname string) (err error) {
- chname, err = CasefoldChannel(chname)
- if err != nil {
- return errNoSuchChannel
- }
-
- cm.Lock()
- found := cm.purgedChannels.Has(chname)
- delete(cm.purgedChannels, chname)
- cm.Unlock()
-
- cm.server.channelRegistry.UnpurgeChannel(chname)
- if !found {
- return errNoSuchChannel
- }
- return nil
- }
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