Mirror of github.com/gissleh/irc
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package irc
import (
"bufio"
"context"
"crypto/rand"
"crypto/tls"
"encoding/binary"
"encoding/hex"
"errors"
"fmt"
mathRand "math/rand"
"net"
"strconv"
"strings"
"sync"
"time"
"git.aiterp.net/gisle/irc/ircutil"
"git.aiterp.net/gisle/irc/isupport"
)
var supportedCaps = []string{
"server-time",
"cap-notify",
"multi-prefix",
"userhost-in-names",
}
// ErrNoConnection is returned if you try to do something requiring a connection,
// but there is none.
var ErrNoConnection = errors.New("irc: no connection")
// A Client is an IRC client. You need to use New to construct it
type Client struct {
id string
config Config
mutex sync.RWMutex
conn net.Conn
ctx context.Context
cancel context.CancelFunc
events chan *Event
sends chan string
lastSend time.Time
capEnabled map[string]bool
capData map[string]string
capsRequested []string
nick string
user string
host string
quit bool
isupport isupport.ISupport
values map[string]interface{}
}
// New creates a new client. The context can be context.Background if you want manually to
// tear down clients upon quitting.
func New(ctx context.Context, config Config) *Client {
client := &Client{
id: generateClientID(),
values: make(map[string]interface{}),
events: make(chan *Event, 64),
sends: make(chan string, 64),
capEnabled: make(map[string]bool),
capData: make(map[string]string),
config: config.WithDefaults(),
}
client.ctx, client.cancel = context.WithCancel(ctx)
go client.handleEventLoop()
go client.handleSendLoop()
return client
}
// Context gets the client's context. It's cancelled if the parent context used
// in New is, or Destroy is called.
func (client *Client) Context() context.Context {
return client.ctx
}
// ID gets the unique identifier for the client, which could be used in data structures
func (client *Client) ID() string {
client.mutex.RLock()
defer client.mutex.RUnlock()
return client.id
}
// Nick gets the nick of the client
func (client *Client) Nick() string {
client.mutex.RLock()
defer client.mutex.RUnlock()
return client.nick
}
// User gets the user/ident of the client
func (client *Client) User() string {
client.mutex.RLock()
defer client.mutex.RUnlock()
return client.user
}
// Host gets the hostname of the client
func (client *Client) Host() string {
client.mutex.RLock()
defer client.mutex.RUnlock()
return client.host
}
// ISupport gets the client's ISupport. This is mutable, and changes to it
// *will* affect the client.
func (client *Client) ISupport() *isupport.ISupport {
return &client.isupport
}
// Connect connects to the server by addr.
func (client *Client) Connect(addr string, ssl bool) (err error) {
var conn net.Conn
if client.Connected() {
client.Disconnect()
}
client.isupport.Reset()
client.mutex.Lock()
client.quit = false
client.mutex.Unlock()
client.EmitSync(context.Background(), NewEvent("client", "connecting"))
if ssl {
conn, err = tls.Dial("tcp", addr, &tls.Config{
InsecureSkipVerify: client.config.SkipSSLVerification,
})
if err != nil {
return err
}
} else {
conn, err = net.Dial("tcp", addr)
if err != nil {
return err
}
}
client.Emit(NewEvent("client", "connect"))
go func() {
reader := bufio.NewReader(conn)
replacer := strings.NewReplacer("\r", "", "\n", "")
for {
line, err := reader.ReadString('\n')
if err != nil {
break
}
line = replacer.Replace(line)
event, err := ParsePacket(line)
if err != nil {
continue
}
client.Emit(event)
}
client.mutex.Lock()
client.conn = nil
client.mutex.Unlock()
client.Emit(NewEvent("client", "disconnect"))
}()
client.mutex.Lock()
client.conn = conn
client.mutex.Unlock()
return nil
}
// Disconnect disconnects from the server. It will either return the
// close error, or ErrNoConnection if there is no connection
func (client *Client) Disconnect() error {
client.mutex.Lock()
defer client.mutex.Unlock()
if client.conn == nil {
return ErrNoConnection
}
client.quit = true
err := client.conn.Close()
return err
}
// Connected returns true if the client has a connection
func (client *Client) Connected() bool {
client.mutex.RLock()
defer client.mutex.RUnlock()
return client.conn != nil
}
// Send sends a line to the server. A line-feed will be automatically added if one
// is not provided.
func (client *Client) Send(line string) error {
client.mutex.RLock()
conn := client.conn
client.mutex.RUnlock()
if conn == nil {
return ErrNoConnection
}
if !strings.HasSuffix(line, "\n") {
line += "\r\n"
}
_, err := conn.Write([]byte(line))
if err != nil {
client.EmitNonBlocking(NewErrorEvent("network", err.Error()))
client.Disconnect()
}
return err
}
// Sendf is Send with a fmt.Sprintf
func (client *Client) Sendf(format string, a ...interface{}) error {
return client.Send(fmt.Sprintf(format, a...))
}
// SendQueued appends a message to a queue that will only send 2 messages
// per second to avoid flooding. If the queue is ull, a goroutine will be
// spawned to queue it, so this function will always return immediately.
// Order may not be guaranteed, however, but if you're sending 64 messages
// at once that may not be your greatest concern.
//
// Failed sends will be discarded quietly to avoid a backup from being
// thrown on a new connection.
func (client *Client) SendQueued(line string) {
select {
case client.sends <- line:
default:
go func() { client.sends <- line }()
}
}
// SendQueuedf is SendQueued with a fmt.Sprintf
func (client *Client) SendQueuedf(format string, a ...interface{}) {
client.SendQueued(fmt.Sprintf(format, a...))
}
// Emit sends an event through the client's event, and it will return immediately
// unless the internal channel is filled up. The returned context can be used to
// wait for the event, or the client's destruction.
func (client *Client) Emit(event Event) context.Context {
event.ctx, event.cancel = context.WithCancel(client.ctx)
client.events <- &event
return event.ctx
}
// EmitNonBlocking is just like emit, but it will spin off a goroutine if the channel is full.
// This lets it be called from other handlers without ever blocking. See Emit for what the
// returned context is for.
func (client *Client) EmitNonBlocking(event Event) context.Context {
event.ctx, event.cancel = context.WithCancel(client.ctx)
select {
case client.events <- &event:
default:
go func() { client.events <- &event }()
}
return event.ctx
}
// EmitSync emits an event and waits for either its context to complete or the one
// passed to it (e.g. a request's context). It's a shorthand for Emit with its
// return value used in a `select` along with a passed context.
func (client *Client) EmitSync(ctx context.Context, event Event) (err error) {
eventCtx := client.Emit(event)
select {
case <-eventCtx.Done():
{
if err := eventCtx.Err(); err != context.Canceled {
return err
}
return nil
}
case <-ctx.Done():
{
return ctx.Err()
}
}
}
// Value gets a client value.
func (client *Client) Value(key string) (v interface{}, ok bool) {
client.mutex.RLock()
v, ok = client.values[key]
client.mutex.RUnlock()
return
}
// SetValue sets a client value.
func (client *Client) SetValue(key string, value interface{}) {
client.mutex.Lock()
client.values[key] = value
client.mutex.Unlock()
}
// Destroy destroys the client, which will lead to a disconnect. Cancelling the
// parent context will do the same.
func (client *Client) Destroy() {
client.Disconnect()
client.cancel()
close(client.sends)
close(client.events)
}
// Destroyed returns true if the client has been destroyed, either by
// Destroy or the parent context.
func (client *Client) Destroyed() bool {
select {
case <-client.ctx.Done():
return true
default:
return false
}
}
// PrivmsgOverhead returns the overhead on a privmsg to the target. If `action` is true,
// it will also count the extra overhead of a CTCP ACTION.
func (client *Client) PrivmsgOverhead(targetName string, action bool) int {
client.mutex.RLock()
defer client.mutex.RUnlock()
// Return a really safe estimate if user or host is missing.
if client.user == "" || client.host == "" {
return 200
}
return ircutil.MessageOverhead(client.nick, client.user, client.host, targetName, action)
}
// Join joins one or more channels without a key.
func (client *Client) Join(channels ...string) error {
return client.Sendf("JOIN %s", strings.Join(channels, ","))
}
func (client *Client) handleEventLoop() {
ticker := time.NewTicker(time.Second * 30)
for {
select {
case event, ok := <-client.events:
{
if !ok {
goto end
}
client.handleEvent(event)
emit(event, client)
event.cancel()
}
case <-ticker.C:
{
event := NewEvent("client", "tick")
event.ctx, event.cancel = context.WithCancel(client.ctx)
client.handleEvent(&event)
emit(&event, client)
event.cancel()
}
case <-client.ctx.Done():
{
goto end
}
}
}
end:
ticker.Stop()
client.Disconnect()
event := NewEvent("client", "destroy")
event.ctx, event.cancel = context.WithCancel(client.ctx)
client.handleEvent(&event)
emit(&event, client)
event.cancel()
}
func (client *Client) handleSendLoop() {
lastRefresh := time.Time{}
queue := 2
for line := range client.sends {
now := time.Now()
deltaTime := now.Sub(lastRefresh)
if deltaTime < time.Second {
queue--
if queue <= 0 {
time.Sleep(time.Second - deltaTime)
lastRefresh = now
queue = 0
}
} else {
lastRefresh = now
}
client.Send(line)
}
}
// handleEvent is always first and gets to break a few rules.
func (client *Client) handleEvent(event *Event) {
// IRCv3 `server-time`
if timeTag, ok := event.Tags["time"]; ok {
serverTime, err := time.Parse(time.RFC3339Nano, timeTag)
if err == nil && serverTime.Year() > 2000 {
event.Time = serverTime
}
}
switch event.name {
// Ping Pong
case "hook.tick":
{
client.mutex.RLock()
lastSend := time.Since(client.lastSend)
client.mutex.RUnlock()
if lastSend > time.Second*120 {
client.Sendf("PING :%x%x%x", mathRand.Int63(), mathRand.Int63(), mathRand.Int63())
}
}
case "packet.ping":
{
message := "PONG"
for _, arg := range event.Args {
message += " " + arg
}
if event.Text != "" {
message += " :" + event.Text
}
client.Send(message + "")
}
// Client Registration
case "client.connect":
{
client.Send("CAP LS 302")
if client.config.Password != "" {
client.Sendf("PASS :%s", client.config.Password)
}
nick := client.config.Nick
client.mutex.RLock()
if client.nick != "" {
nick = client.nick
}
client.mutex.RUnlock()
client.Sendf("NICK %s", nick)
client.Sendf("USER %s 8 * :%s", client.config.User, client.config.RealName)
}
case "packet.001":
{
client.mutex.Lock()
client.nick = event.Args[0]
client.mutex.Unlock()
client.Sendf("WHO %s", event.Args[0])
}
case "packet.443":
{
client.mutex.RLock()
hasRegistered := client.nick != ""
client.mutex.RUnlock()
if !hasRegistered {
nick := event.Args[1]
// "AltN" -> "AltN+1", ...
prev := client.config.Nick
sent := false
for _, alt := range client.config.Alternatives {
if nick == prev {
client.Sendf("NICK %s", alt)
sent = true
break
}
prev = alt
}
if !sent {
// "LastAlt" -> "Nick23962"
client.Sendf("NICK %s%05d", client.config.Nick, mathRand.Int31n(99999))
}
}
}
// Handle ISupport
case "packet.005":
{
for _, token := range event.Args[1:] {
kvpair := strings.Split(token, "=")
if len(kvpair) == 2 {
client.isupport.Set(kvpair[0], kvpair[1])
} else {
client.isupport.Set(kvpair[0], "")
}
}
}
// Capability negotiation
case "packet.cap":
{
capCommand := event.Args[1]
capTokens := strings.Split(event.Text, " ")
switch capCommand {
case "LS":
{
for _, token := range capTokens {
split := strings.SplitN(token, "=", 2)
key := split[0]
if len(key) == 0 {
continue
}
if len(split) == 2 {
client.capData[key] = split[1]
}
for i := range supportedCaps {
if supportedCaps[i] == token {
client.mutex.Lock()
client.capsRequested = append(client.capsRequested, token)
client.mutex.Unlock()
break
}
}
}
if len(event.Args) < 3 || event.Args[2] != "*" {
client.mutex.RLock()
requestedCount := len(client.capsRequested)
client.mutex.RUnlock()
if requestedCount > 0 {
client.mutex.RLock()
requestedCaps := strings.Join(client.capsRequested, " ")
client.mutex.RUnlock()
client.Send("CAP REQ :" + requestedCaps)
} else {
client.Send("CAP END")
}
}
}
case "ACK":
{
for _, token := range capTokens {
client.mutex.Lock()
if client.capEnabled[token] {
client.capEnabled[token] = true
}
client.mutex.Unlock()
}
client.Send("CAP END")
}
case "NAK":
{
// Remove offenders
for _, token := range capTokens {
client.mutex.Lock()
for i := range client.capsRequested {
if token == client.capsRequested[i] {
client.capsRequested = append(client.capsRequested[:i], client.capsRequested[i+1:]...)
break
}
}
client.mutex.Unlock()
}
client.mutex.RLock()
requestedCaps := strings.Join(client.capsRequested, " ")
client.mutex.RUnlock()
client.Send("CAP REQ :" + requestedCaps)
}
case "NEW":
{
requests := make([]string, 0, len(capTokens))
for _, token := range capTokens {
for i := range supportedCaps {
if supportedCaps[i] == token {
requests = append(requests, token)
}
}
}
if len(requests) > 0 {
client.Send("CAP REQ :" + strings.Join(requests, " "))
}
}
case "DEL":
{
for _, token := range capTokens {
client.mutex.Lock()
if client.capEnabled[token] {
client.capEnabled[token] = false
}
client.mutex.Unlock()
}
}
}
}
// User/host detection
case "packet.352": // WHO reply
{
// Example args: test * ~irce 127.0.0.1 localhost.localnetwork Gissleh H :0 ...
nick := event.Args[5]
user := event.Args[2]
host := event.Args[3]
if nick == client.nick {
client.mutex.Lock()
client.user = user
client.host = host
client.mutex.Unlock()
}
}
case "packet.chghost":
{
if event.Nick == client.nick {
client.mutex.Lock()
client.user = event.Args[1]
client.host = event.Args[2]
client.mutex.Unlock()
}
}
}
}
func generateClientID() string {
bytes := make([]byte, 12)
_, err := rand.Read(bytes)
// Ugly fallback if crypto rand doesn't work.
if err != nil {
rng := mathRand.NewSource(time.Now().UnixNano())
result := strconv.FormatInt(rng.Int63(), 16)
for len(result) < 24 {
result += strconv.FormatInt(rng.Int63(), 16)
}
return result[:24]
}
binary.BigEndian.PutUint32(bytes, uint32(time.Now().Unix()))
return hex.EncodeToString(bytes)
}