// Copyright 2018 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"crypto/tls"
"log"
"strconv"
"strings"
"time"
irc "github.com/fluffle/goirc/client"
)
const (
pingFrequencySecs = 60
connectionTimeoutSecs = 30
nickservWaitSecs = 10
ircConnectMaxBackoffSecs = 300
ircConnectBackoffResetSecs = 1800
)
func loggerHandler(_ *irc.Conn, line *irc.Line) {
log.Printf("Received: '%s'", line.Raw)
}
type ChannelState struct {
Channel IRCChannel
BackoffCounter Delayer
}
type IRCNotifier struct {
// Nick stores the nickname specified in the config, because irc.Client
// might change its copy.
Nick string
NickPassword string
Client *irc.Conn
StopRunning chan bool
StoppedRunning chan bool
AlertMsgs chan AlertMsg
// irc.Conn has a Connected() method that can tell us wether the TCP
// connection is up, and thus if we should trigger connect/disconnect.
// We need to track the session establishment also at a higher level to
// understand when the server has accepted us and thus when we can join
// channels, send notices, etc.
sessionUp bool
sessionUpSignal chan bool
sessionDownSignal chan bool
PreJoinChannels []IRCChannel
JoinedChannels map[string]ChannelState
UsePrivmsg bool
NickservDelayWait time.Duration
BackoffCounter Delayer
}
func NewIRCNotifier(config *Config, alertMsgs chan AlertMsg) (*IRCNotifier, error) {
ircConfig := irc.NewConfig(config.IRCNick)
ircConfig.Me.Ident = config.IRCNick
ircConfig.Me.Name = config.IRCRealName
ircConfig.Server = strings.Join(
[]string{config.IRCHost, strconv.Itoa(config.IRCPort)}, ":")
ircConfig.SSL = config.IRCUseSSL
ircConfig.SSLConfig = &tls.Config{
ServerName: config.IRCHost,
InsecureSkipVerify: !config.IRCVerifySSL,
}
ircConfig.PingFreq = pingFrequencySecs * time.Second
ircConfig.Timeout = connectionTimeoutSecs * time.Second
ircConfig.NewNick = func(n string) string { return n + "^" }
backoffCounter := NewBackoff(
ircConnectMaxBackoffSecs, ircConnectBackoffResetSecs,
time.Second)
notifier := &IRCNotifier{
Nick: config.IRCNick,
NickPassword: config.IRCNickPass,
Client: irc.Client(ircConfig),
StopRunning: make(chan bool),
StoppedRunning: make(chan bool),
AlertMsgs: alertMsgs,
sessionUpSignal: make(chan bool),
sessionDownSignal: make(chan bool),
PreJoinChannels: config.IRCChannels,
JoinedChannels: make(map[string]ChannelState),
UsePrivmsg: config.UsePrivmsg,
NickservDelayWait: nickservWaitSecs * time.Second,
BackoffCounter: backoffCounter,
}
notifier.Client.HandleFunc(irc.CONNECTED,
func(*irc.Conn, *irc.Line) {
log.Printf("Session established")
notifier.sessionUpSignal <- true
})
notifier.Client.HandleFunc(irc.DISCONNECTED,
func(*irc.Conn, *irc.Line) {
log.Printf("Disconnected from IRC")
notifier.sessionDownSignal <- false
})
notifier.Client.HandleFunc(irc.KICK,
func(_ *irc.Conn, line *irc.Line) {
notifier.HandleKick(line.Args[1], line.Args[0])
})
for _, event := range []string{irc.NOTICE, "433"} {
notifier.Client.HandleFunc(event, loggerHandler)
}
return notifier, nil
}
func (notifier *IRCNotifier) HandleKick(nick string, channel string) {
if nick != notifier.Client.Me().Nick {
// received kick info for somebody else
return
}
state, ok := notifier.JoinedChannels[channel]
if !ok {
log.Printf("Being kicked out of non-joined channel (%s), ignoring", channel)
return
}
log.Printf("Being kicked out of %s, re-joining", channel)
go func() {
state.BackoffCounter.Delay()
notifier.Client.Join(state.Channel.Name, state.Channel.Password)
}()
}
func (notifier *IRCNotifier) CleanupChannels() {
log.Printf("Deregistering all channels.")
notifier.JoinedChannels = make(map[string]ChannelState)
}
func (notifier *IRCNotifier) JoinChannel(channel *IRCChannel) {
if _, joined := notifier.JoinedChannels[channel.Name]; joined {
return
}
log.Printf("Joining %s", channel.Name)
notifier.Client.Join(channel.Name, channel.Password)
state := ChannelState{
Channel: *channel,
BackoffCounter: NewBackoff(
ircConnectMaxBackoffSecs, ircConnectBackoffResetSecs,
time.Second),
}
notifier.JoinedChannels[channel.Name] = state
}
func (notifier *IRCNotifier) JoinChannels() {
for _, channel := range notifier.PreJoinChannels {
notifier.JoinChannel(&channel)
}
}
func (notifier *IRCNotifier) MaybeIdentifyNick() {
if notifier.NickPassword == "" {
return
}
// Very lazy/optimistic, but this is good enough for my irssi config,
// so it should work here as well.
currentNick := notifier.Client.Me().Nick
if currentNick != notifier.Nick {
log.Printf("My nick is '%s', sending GHOST to NickServ to get '%s'",
currentNick, notifier.Nick)
notifier.Client.Privmsgf("NickServ", "GHOST %s %s", notifier.Nick,
notifier.NickPassword)
time.Sleep(notifier.NickservDelayWait)
log.Printf("Changing nick to '%s'", notifier.Nick)
notifier.Client.Nick(notifier.Nick)
}
log.Printf("Sending IDENTIFY to NickServ")
notifier.Client.Privmsgf("NickServ", "IDENTIFY %s", notifier.NickPassword)
time.Sleep(notifier.NickservDelayWait)
}
func (notifier *IRCNotifier) MaybeSendAlertMsg(alertMsg *AlertMsg) {
if !notifier.sessionUp {
log.Printf("Cannot send alert to %s : IRC not connected",
alertMsg.Channel)
return
}
notifier.JoinChannel(&IRCChannel{Name: alertMsg.Channel})
if notifier.UsePrivmsg {
notifier.Client.Privmsg(alertMsg.Channel, alertMsg.Alert)
} else {
notifier.Client.Notice(alertMsg.Channel, alertMsg.Alert)
}
}
func (notifier *IRCNotifier) Run() {
keepGoing := true
for keepGoing {
if !notifier.Client.Connected() {
log.Printf("Connecting to IRC %s", notifier.Client.Config().Server)
notifier.BackoffCounter.Delay()
if err := notifier.Client.Connect(); err != nil {
log.Printf("Could not connect to IRC: %s", err)
select {
case <-notifier.StopRunning:
log.Printf("IRC routine not connected but asked to terminate")
keepGoing = false
default:
}
continue
}
log.Printf("Connected to IRC server, waiting to establish session")
}
select {
case alertMsg := <-notifier.AlertMsgs:
notifier.MaybeSendAlertMsg(&alertMsg)
case <-notifier.sessionUpSignal:
notifier.sessionUp = true
notifier.MaybeIdentifyNick()
notifier.JoinChannels()
case <-notifier.sessionDownSignal:
notifier.sessionUp = false
notifier.CleanupChannels()
notifier.Client.Quit("see ya")
case <-notifier.StopRunning:
log.Printf("IRC routine asked to terminate")
keepGoing = false
}
}
if notifier.Client.Connected() {
log.Printf("IRC client connected, quitting")
notifier.Client.Quit("see ya")
if notifier.sessionUp {
log.Printf("Session is up, wait for IRC disconnect to complete")
select {
case <-notifier.sessionDownSignal:
case <-time.After(notifier.Client.Config().Timeout):
log.Printf("Timeout while waiting for IRC disconnect to complete, stopping anyway")
}
}
}
notifier.StoppedRunning <- true
}