summaryrefslogtreecommitdiff
path: root/vendor/github.com/fluffle/goirc/client/connection.go
blob: 12d0e59d27c1e963f933577c1b83b1ebe5740c2a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
package client

import (
	"bufio"
	"crypto/tls"
	"fmt"
	"io"
	"net"
	"net/url"
	"strings"
	"sync"
	"time"

	"github.com/fluffle/goirc/logging"
	"github.com/fluffle/goirc/state"
	"golang.org/x/net/proxy"
)

// Conn encapsulates a connection to a single IRC server. Create
// one with Client or SimpleClient.
type Conn struct {
	// For preventing races on (dis)connect.
	mu sync.RWMutex

	// Contains parameters that people can tweak to change client behaviour.
	cfg *Config

	// Handlers
	intHandlers *hSet
	fgHandlers  *hSet
	bgHandlers  *hSet

	// State tracker for nicks and channels
	st         state.Tracker
	stRemovers []Remover

	// I/O stuff to server
	dialer      *net.Dialer
	proxyDialer proxy.Dialer
	sock        net.Conn
	io          *bufio.ReadWriter
	in          chan *Line
	out         chan string
	connected   bool

	// Control channel and WaitGroup for goroutines
	die chan struct{}
	wg  sync.WaitGroup

	// Internal counters for flood protection
	badness  time.Duration
	lastsent time.Time
}

// Config contains options that can be passed to Client to change the
// behaviour of the library during use. It is recommended that NewConfig
// is used to create this struct rather than instantiating one directly.
// Passing a Config with no Nick in the Me field to Client will result
// in unflattering consequences.
type Config struct {
	// Set this to provide the Nick, Ident and Name for the client to use.
	// It is recommended to call Conn.Me to get up-to-date information
	// about the current state of the client's IRC nick after connecting.
	Me *state.Nick

	// Hostname to connect to and optional connect password.
	// Changing these after connection will have no effect until the
	// client reconnects.
	Server, Pass string

	// Are we connecting via SSL? Do we care about certificate validity?
	// Changing these after connection will have no effect until the
	// client reconnects.
	SSL       bool
	SSLConfig *tls.Config

	// To connect via proxy set the proxy url here.
	// Changing these after connection will have no effect until the
	// client reconnects.
	Proxy string

	// Local address to bind to when connecting to the server.
	LocalAddr string

	// To attempt RFC6555 parallel IPv4 and IPv6 connections if both
	// address families are returned for a hostname, set this to true.
	// Passed through to https://golang.org/pkg/net/#Dialer
	DualStack bool

	// Replaceable function to customise the 433 handler's new nick.
	// By default an underscore "_" is appended to the current nick.
	NewNick func(string) string

	// Client->server ping frequency, in seconds. Defaults to 3m.
	// Set to 0 to disable client-side pings.
	PingFreq time.Duration

	// The duration before a connection timeout is triggered. Defaults to 1m.
	// Set to 0 to wait indefinitely.
	Timeout time.Duration

	// Set this to true to disable flood protection and false to re-enable.
	Flood bool

	// Sent as the reply to a CTCP VERSION message.
	Version string

	// Sent as the default QUIT message if Quit is called with no args.
	QuitMessage string

	// Configurable panic recovery for all handlers.
	// Defaults to logging an error, see LogPanic.
	Recover func(*Conn, *Line)

	// Split PRIVMSGs, NOTICEs and CTCPs longer than SplitLen characters
	// over multiple lines. Default to 450 if not set.
	SplitLen int
}

// NewConfig creates a Config struct containing sensible defaults.
// It takes one required argument: the nick to use for the client.
// Subsequent string arguments set the client's ident and "real"
// name, but these are optional.
func NewConfig(nick string, args ...string) *Config {
	cfg := &Config{
		Me:       &state.Nick{Nick: nick},
		PingFreq: 3 * time.Minute,
		NewNick:  func(s string) string { return s + "_" },
		Recover:  (*Conn).LogPanic, // in dispatch.go
		SplitLen: defaultSplit,
		Timeout:  60 * time.Second,
	}
	cfg.Me.Ident = "goirc"
	if len(args) > 0 && args[0] != "" {
		cfg.Me.Ident = args[0]
	}
	cfg.Me.Name = "Powered by GoIRC"
	if len(args) > 1 && args[1] != "" {
		cfg.Me.Name = args[1]
	}
	cfg.Version = "Powered by GoIRC"
	cfg.QuitMessage = "GoBye!"
	return cfg
}

// SimpleClient creates a new Conn, passing its arguments to NewConfig.
// If you don't need to change any client options and just want to get
// started quickly, this is a convenient shortcut.
func SimpleClient(nick string, args ...string) *Conn {
	conn := Client(NewConfig(nick, args...))
	return conn
}

// Client takes a Config struct and returns a new Conn ready to have
// handlers added and connect to a server.
func Client(cfg *Config) *Conn {
	if cfg == nil {
		cfg = NewConfig("__idiot__")
	}
	if cfg.Me == nil || cfg.Me.Nick == "" || cfg.Me.Ident == "" {
		cfg.Me = &state.Nick{Nick: "__idiot__"}
		cfg.Me.Ident = "goirc"
		cfg.Me.Name = "Powered by GoIRC"
	}

	dialer := new(net.Dialer)
	dialer.Timeout = cfg.Timeout
	dialer.DualStack = cfg.DualStack
	if cfg.LocalAddr != "" {
		if !hasPort(cfg.LocalAddr) {
			cfg.LocalAddr += ":0"
		}

		local, err := net.ResolveTCPAddr("tcp", cfg.LocalAddr)
		if err == nil {
			dialer.LocalAddr = local
		} else {
			logging.Error("irc.Client(): Cannot resolve local address %s: %s", cfg.LocalAddr, err)
		}
	}

	conn := &Conn{
		cfg:         cfg,
		dialer:      dialer,
		intHandlers: handlerSet(),
		fgHandlers:  handlerSet(),
		bgHandlers:  handlerSet(),
		stRemovers:  make([]Remover, 0, len(stHandlers)),
		lastsent:    time.Now(),
	}
	conn.addIntHandlers()
	return conn
}

// Connected returns true if the client is successfully connected to
// an IRC server. It becomes true when the TCP connection is established,
// and false again when the connection is closed.
func (conn *Conn) Connected() bool {
	conn.mu.RLock()
	defer conn.mu.RUnlock()
	return conn.connected
}

// Config returns a pointer to the Config struct used by the client.
// Many of the elements of Config may be changed at any point to
// affect client behaviour. To disable flood protection temporarily,
// for example, a handler could do:
//
//     conn.Config().Flood = true
//     // Send many lines to the IRC server, risking "excess flood"
//     conn.Config().Flood = false
//
func (conn *Conn) Config() *Config {
	return conn.cfg
}

// Me returns a state.Nick that reflects the client's IRC nick at the
// time it is called. If state tracking is enabled, this comes from
// the tracker, otherwise it is equivalent to conn.cfg.Me.
func (conn *Conn) Me() *state.Nick {
	if conn.st != nil {
		conn.cfg.Me = conn.st.Me()
	}
	return conn.cfg.Me
}

// StateTracker returns the state tracker being used by the client,
// if tracking is enabled, and nil otherwise.
func (conn *Conn) StateTracker() state.Tracker {
	return conn.st
}

// EnableStateTracking causes the client to track information about
// all channels it is joined to, and all the nicks in those channels.
// This can be rather handy for a number of bot-writing tasks. See
// the state package for more details.
//
// NOTE: Calling this while connected to an IRC server may cause the
// state tracker to become very confused all over STDERR if logging
// is enabled. State tracking should enabled before connecting or
// at a pinch while the client is not joined to any channels.
func (conn *Conn) EnableStateTracking() {
	conn.mu.Lock()
	defer conn.mu.Unlock()
	if conn.st == nil {
		n := conn.cfg.Me
		conn.st = state.NewTracker(n.Nick)
		conn.st.NickInfo(n.Nick, n.Ident, n.Host, n.Name)
		conn.cfg.Me = conn.st.Me()
		conn.addSTHandlers()
	}
}

// DisableStateTracking causes the client to stop tracking information
// about the channels and nicks it knows of. It will also wipe current
// state from the state tracker.
func (conn *Conn) DisableStateTracking() {
	conn.mu.Lock()
	defer conn.mu.Unlock()
	if conn.st != nil {
		conn.cfg.Me = conn.st.Me()
		conn.delSTHandlers()
		conn.st.Wipe()
		conn.st = nil
	}
}

// Per-connection state initialisation.
func (conn *Conn) initialise() {
	conn.io = nil
	conn.sock = nil
	conn.in = make(chan *Line, 32)
	conn.out = make(chan string, 32)
	conn.die = make(chan struct{})
	if conn.st != nil {
		conn.st.Wipe()
	}
}

// ConnectTo connects the IRC client to "host[:port]", which should be either
// a hostname or an IP address, with an optional port. It sets the client's
// Config.Server to host, Config.Pass to pass if one is provided, and then
// calls Connect.
func (conn *Conn) ConnectTo(host string, pass ...string) error {
	conn.cfg.Server = host
	if len(pass) > 0 {
		conn.cfg.Pass = pass[0]
	}
	return conn.Connect()
}

// Connect connects the IRC client to the server configured in Config.Server.
// To enable explicit SSL on the connection to the IRC server, set Config.SSL
// to true before calling Connect(). The port will default to 6697 if SSL is
// enabled, and 6667 otherwise.
// To enable connecting via a proxy server, set Config.Proxy to the proxy URL
// (example socks5://localhost:9000) before calling Connect().
//
// Upon successful connection, Connected will return true and a REGISTER event
// will be fired. This is mostly for internal use; it is suggested that a
// handler for the CONNECTED event is used to perform any initial client work
// like joining channels and sending messages.
func (conn *Conn) Connect() error {
	// We don't want to hold conn.mu while firing the REGISTER event,
	// and it's much easier and less error prone to defer the unlock,
	// so the connect mechanics have been delegated to internalConnect.
	err := conn.internalConnect()
	if err == nil {
		conn.dispatch(&Line{Cmd: REGISTER, Time: time.Now()})
	}
	return err
}

// internalConnect handles the work of actually connecting to the server.
func (conn *Conn) internalConnect() error {
	conn.mu.Lock()
	defer conn.mu.Unlock()
	conn.initialise()

	if conn.cfg.Server == "" {
		return fmt.Errorf("irc.Connect(): cfg.Server must be non-empty")
	}
	if conn.connected {
		return fmt.Errorf("irc.Connect(): Cannot connect to %s, already connected.", conn.cfg.Server)
	}

	if !hasPort(conn.cfg.Server) {
		if conn.cfg.SSL {
			conn.cfg.Server = net.JoinHostPort(conn.cfg.Server, "6697")
		} else {
			conn.cfg.Server = net.JoinHostPort(conn.cfg.Server, "6667")
		}
	}

	if conn.cfg.Proxy != "" {
		proxyURL, err := url.Parse(conn.cfg.Proxy)
		if err != nil {
			return err
		}
		conn.proxyDialer, err = proxy.FromURL(proxyURL, conn.dialer)
		if err != nil {
			return err
		}

		logging.Info("irc.Connect(): Connecting to %s.", conn.cfg.Server)
		if s, err := conn.proxyDialer.Dial("tcp", conn.cfg.Server); err == nil {
			conn.sock = s
		} else {
			return err
		}
	} else {
		logging.Info("irc.Connect(): Connecting to %s.", conn.cfg.Server)
		if s, err := conn.dialer.Dial("tcp", conn.cfg.Server); err == nil {
			conn.sock = s
		} else {
			return err
		}
	}

	if conn.cfg.SSL {
		logging.Info("irc.Connect(): Performing SSL handshake.")
		s := tls.Client(conn.sock, conn.cfg.SSLConfig)
		if err := s.Handshake(); err != nil {
			return err
		}
		conn.sock = s
	}

	conn.postConnect(true)
	conn.connected = true
	return nil
}

// postConnect performs post-connection setup, for ease of testing.
func (conn *Conn) postConnect(start bool) {
	conn.io = bufio.NewReadWriter(
		bufio.NewReader(conn.sock),
		bufio.NewWriter(conn.sock))
	if start {
		conn.wg.Add(3)
		go conn.send()
		go conn.recv()
		go conn.runLoop()
		if conn.cfg.PingFreq > 0 {
			conn.wg.Add(1)
			go conn.ping()
		}
	}
}

// hasPort returns true if the string hostname has a :port suffix.
// It was copied from net/http for great justice.
func hasPort(s string) bool {
	return strings.LastIndex(s, ":") > strings.LastIndex(s, "]")
}

// send is started as a goroutine after a connection is established.
// It shuttles data from the output channel to write(), and is killed
// when Conn.die is closed.
func (conn *Conn) send() {
	for {
		select {
		case line := <-conn.out:
			if err := conn.write(line); err != nil {
				logging.Error("irc.send(): %s", err.Error())
				// We can't defer this, because Close() waits for it.
				conn.wg.Done()
				conn.Close()
				return
			}
		case <-conn.die:
			// control channel closed, bail out
			conn.wg.Done()
			return
		}
	}
}

// recv is started as a goroutine after a connection is established.
// It receives "\r\n" terminated lines from the server, parses them into
// Lines, and sends them to the input channel.
func (conn *Conn) recv() {
	for {
		s, err := conn.io.ReadString('\n')
		if err != nil {
			if err != io.EOF {
				logging.Error("irc.recv(): %s", err.Error())
			}
			// We can't defer this, because Close() waits for it.
			conn.wg.Done()
			conn.Close()
			return
		}
		s = strings.Trim(s, "\r\n")
		logging.Debug("<- %s", s)

		if line := ParseLine(s); line != nil {
			line.Time = time.Now()
			conn.in <- line
		} else {
			logging.Warn("irc.recv(): problems parsing line:\n  %s", s)
		}
	}
}

// ping is started as a goroutine after a connection is established, as
// long as Config.PingFreq >0. It pings the server every PingFreq seconds.
func (conn *Conn) ping() {
	defer conn.wg.Done()
	tick := time.NewTicker(conn.cfg.PingFreq)
	for {
		select {
		case <-tick.C:
			conn.Ping(fmt.Sprintf("%d", time.Now().UnixNano()))
		case <-conn.die:
			// control channel closed, bail out
			tick.Stop()
			return
		}
	}
}

// runLoop is started as a goroutine after a connection is established.
// It pulls Lines from the input channel and dispatches them to any
// handlers that have been registered for that IRC verb.
func (conn *Conn) runLoop() {
	defer conn.wg.Done()
	for {
		select {
		case line := <-conn.in:
			conn.dispatch(line)
		case <-conn.die:
			// control channel closed, bail out
			return
		}
	}
}

// write writes a \r\n terminated line of output to the connected server,
// using Hybrid's algorithm to rate limit if conn.cfg.Flood is false.
func (conn *Conn) write(line string) error {
	if !conn.cfg.Flood {
		if t := conn.rateLimit(len(line)); t != 0 {
			// sleep for the current line's time value before sending it
			logging.Info("irc.rateLimit(): Flood! Sleeping for %.2f secs.",
				t.Seconds())
			<-time.After(t)
		}
	}

	if _, err := conn.io.WriteString(line + "\r\n"); err != nil {
		return err
	}
	if err := conn.io.Flush(); err != nil {
		return err
	}
	if strings.HasPrefix(line, "PASS") {
		line = "PASS **************"
	}
	logging.Debug("-> %s", line)
	return nil
}

// rateLimit implements Hybrid's flood control algorithm for outgoing lines.
func (conn *Conn) rateLimit(chars int) time.Duration {
	// Hybrid's algorithm allows for 2 seconds per line and an additional
	// 1/120 of a second per character on that line.
	linetime := 2*time.Second + time.Duration(chars)*time.Second/120
	elapsed := time.Now().Sub(conn.lastsent)
	if conn.badness += linetime - elapsed; conn.badness < 0 {
		// negative badness times are badness...
		conn.badness = 0
	}
	conn.lastsent = time.Now()
	// If we've sent more than 10 second's worth of lines according to the
	// calculation above, then we're at risk of "Excess Flood".
	if conn.badness > 10*time.Second {
		return linetime
	}
	return 0
}

// Close tears down all connection-related state. It is called when either
// the sending or receiving goroutines encounter an error.
// It may also be used to forcibly shut down the connection to the server.
func (conn *Conn) Close() error {
	// Guard against double-call of Close() if we get an error in send()
	// as calling sock.Close() will cause recv() to receive EOF in readstring()
	conn.mu.Lock()
	if !conn.connected {
		conn.mu.Unlock()
		return nil
	}
	logging.Info("irc.Close(): Disconnected from server.")
	conn.connected = false
	err := conn.sock.Close()
	close(conn.die)
	// Drain both in and out channels to avoid a deadlock if the buffers
	// have filled. See TestSendDeadlockOnFullBuffer in connection_test.go.
	conn.drainIn()
	conn.drainOut()
	conn.wg.Wait()
	conn.mu.Unlock()
	// Dispatch after closing connection but before reinit
	// so event handlers can still access state information.
	conn.dispatch(&Line{Cmd: DISCONNECTED, Time: time.Now()})
	return err
}

// drainIn sends all data buffered in conn.in to /dev/null.
func (conn *Conn) drainIn() {
	for {
		select {
		case <-conn.in:
		default:
			return
		}
	}
}

// drainOut does the same for conn.out. Generics!
func (conn *Conn) drainOut() {
	for {
		select {
		case <-conn.out:
		default:
			return
		}
	}
}

// Dumps a load of information about the current state of the connection to a
// string for debugging state tracking and other such things.
func (conn *Conn) String() string {
	str := "GoIRC Connection\n"
	str += "----------------\n\n"
	if conn.Connected() {
		str += "Connected to " + conn.cfg.Server + "\n\n"
	} else {
		str += "Not currently connected!\n\n"
	}
	str += conn.Me().String() + "\n"
	if conn.st != nil {
		str += conn.st.String() + "\n"
	}
	return str
}