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
#[cfg(test)]
mod agent_gather_test;
#[cfg(test)]
mod agent_test;
#[cfg(test)]
mod agent_transport_test;
#[cfg(test)]
pub(crate) mod agent_vnet_test;
pub mod agent_config;
pub mod agent_gather;
pub(crate) mod agent_internal;
pub mod agent_selector;
pub mod agent_stats;
pub mod agent_transport;
use crate::candidate::*;
use crate::error::*;
use crate::external_ip_mapper::*;
use crate::mdns::*;
use crate::network_type::*;
use crate::state::*;
use crate::udp_mux::UDPMux;
use crate::udp_network::UDPNetwork;
use crate::url::*;
use agent_config::*;
use agent_internal::*;
use agent_stats::*;
use mdns::conn::*;
use std::collections::HashMap;
use std::net::{Ipv4Addr, SocketAddr};
use stun::{agent::*, attributes::*, fingerprint::*, integrity::*, message::*, xoraddr::*};
use util::{vnet::net::*, Buffer};
use crate::agent::agent_gather::GatherCandidatesInternalParams;
use crate::rand::*;
use crate::tcp_type::TcpType;
use std::future::Future;
use std::pin::Pin;
use std::sync::atomic::{AtomicU8, AtomicUsize, Ordering};
use std::sync::Arc;
use std::time::SystemTime;
use tokio::sync::{broadcast, mpsc, Mutex};
use tokio::time::{Duration, Instant};
#[derive(Debug, Clone)]
pub(crate) struct BindingRequest {
pub(crate) timestamp: Instant,
pub(crate) transaction_id: TransactionId,
pub(crate) destination: SocketAddr,
pub(crate) is_use_candidate: bool,
}
impl Default for BindingRequest {
fn default() -> Self {
Self {
timestamp: Instant::now(),
transaction_id: TransactionId::default(),
destination: SocketAddr::new(Ipv4Addr::new(0, 0, 0, 0).into(), 0),
is_use_candidate: false,
}
}
}
pub type OnConnectionStateChangeHdlrFn = Box<
dyn (FnMut(ConnectionState) -> Pin<Box<dyn Future<Output = ()> + Send + 'static>>)
+ Send
+ Sync,
>;
pub type OnSelectedCandidatePairChangeHdlrFn = Box<
dyn (FnMut(
&Arc<dyn Candidate + Send + Sync>,
&Arc<dyn Candidate + Send + Sync>,
) -> Pin<Box<dyn Future<Output = ()> + Send + 'static>>)
+ Send
+ Sync,
>;
pub type OnCandidateHdlrFn = Box<
dyn (FnMut(
Option<Arc<dyn Candidate + Send + Sync>>,
) -> Pin<Box<dyn Future<Output = ()> + Send + 'static>>)
+ Send
+ Sync,
>;
pub type GatherCandidateCancelFn = Box<dyn Fn() + Send + Sync>;
struct ChanReceivers {
chan_state_rx: mpsc::Receiver<ConnectionState>,
chan_candidate_rx: mpsc::Receiver<Option<Arc<dyn Candidate + Send + Sync>>>,
chan_candidate_pair_rx: mpsc::Receiver<()>,
}
pub struct Agent {
pub(crate) internal: Arc<AgentInternal>,
pub(crate) udp_network: UDPNetwork,
pub(crate) interface_filter: Arc<Option<InterfaceFilterFn>>,
pub(crate) mdns_mode: MulticastDnsMode,
pub(crate) mdns_name: String,
pub(crate) mdns_conn: Option<Arc<DnsConn>>,
pub(crate) net: Arc<Net>,
pub(crate) ext_ip_mapper: Arc<Option<ExternalIpMapper>>,
pub(crate) gathering_state: Arc<AtomicU8>,
pub(crate) candidate_types: Vec<CandidateType>,
pub(crate) urls: Vec<Url>,
pub(crate) network_types: Vec<NetworkType>,
pub(crate) gather_candidate_cancel: Option<GatherCandidateCancelFn>,
}
impl Agent {
pub async fn new(config: AgentConfig) -> Result<Self> {
let mut mdns_name = config.multicast_dns_host_name.clone();
if mdns_name.is_empty() {
mdns_name = generate_multicast_dns_name();
}
if !mdns_name.ends_with(".local") || mdns_name.split('.').count() != 2 {
return Err(Error::ErrInvalidMulticastDnshostName);
}
let mut mdns_mode = config.multicast_dns_mode;
if mdns_mode == MulticastDnsMode::Unspecified {
mdns_mode = MulticastDnsMode::QueryOnly;
}
let mdns_conn =
match create_multicast_dns(mdns_mode, &mdns_name, &config.multicast_dns_dest_addr) {
Ok(c) => c,
Err(err) => {
log::warn!("Failed to initialize mDNS {}: {}", mdns_name, err);
None
}
};
let (mut ai, chan_receivers) = AgentInternal::new(&config);
let (chan_state_rx, chan_candidate_rx, chan_candidate_pair_rx) = (
chan_receivers.chan_state_rx,
chan_receivers.chan_candidate_rx,
chan_receivers.chan_candidate_pair_rx,
);
config.init_with_defaults(&mut ai);
let candidate_types = if config.candidate_types.is_empty() {
default_candidate_types()
} else {
config.candidate_types.clone()
};
if ai.lite.load(Ordering::SeqCst)
&& (candidate_types.len() != 1 || candidate_types[0] != CandidateType::Host)
{
Self::close_multicast_conn(&mdns_conn).await;
return Err(Error::ErrLiteUsingNonHostCandidates);
}
if !config.urls.is_empty()
&& !contains_candidate_type(CandidateType::ServerReflexive, &candidate_types)
&& !contains_candidate_type(CandidateType::Relay, &candidate_types)
{
Self::close_multicast_conn(&mdns_conn).await;
return Err(Error::ErrUselessUrlsProvided);
}
let ext_ip_mapper = match config.init_ext_ip_mapping(mdns_mode, &candidate_types) {
Ok(ext_ip_mapper) => ext_ip_mapper,
Err(err) => {
Self::close_multicast_conn(&mdns_conn).await;
return Err(err);
}
};
let net = if let Some(net) = config.net {
if net.is_virtual() {
log::warn!("vnet is enabled");
if mdns_mode != MulticastDnsMode::Disabled {
log::warn!("vnet does not support mDNS yet");
}
}
net
} else {
Arc::new(Net::new(None))
};
let agent = Self {
udp_network: config.udp_network,
internal: Arc::new(ai),
interface_filter: Arc::clone(&config.interface_filter),
mdns_mode,
mdns_name,
mdns_conn,
net,
ext_ip_mapper: Arc::new(ext_ip_mapper),
gathering_state: Arc::new(AtomicU8::new(0)),
candidate_types,
urls: config.urls.clone(),
network_types: config.network_types.clone(),
gather_candidate_cancel: None,
};
agent
.internal
.start_on_connection_state_change_routine(
chan_state_rx,
chan_candidate_rx,
chan_candidate_pair_rx,
)
.await;
if let Err(err) = agent.restart(config.local_ufrag, config.local_pwd).await {
Self::close_multicast_conn(&agent.mdns_conn).await;
let _ = agent.close().await;
return Err(err);
}
Ok(agent)
}
pub async fn on_connection_state_change(&self, f: OnConnectionStateChangeHdlrFn) {
let mut on_connection_state_change_hdlr =
self.internal.on_connection_state_change_hdlr.lock().await;
*on_connection_state_change_hdlr = Some(f);
}
pub async fn on_selected_candidate_pair_change(&self, f: OnSelectedCandidatePairChangeHdlrFn) {
let mut on_selected_candidate_pair_change_hdlr = self
.internal
.on_selected_candidate_pair_change_hdlr
.lock()
.await;
*on_selected_candidate_pair_change_hdlr = Some(f);
}
pub async fn on_candidate(&self, f: OnCandidateHdlrFn) {
let mut on_candidate_hdlr = self.internal.on_candidate_hdlr.lock().await;
*on_candidate_hdlr = Some(f);
}
pub async fn add_remote_candidate(&self, c: &Arc<dyn Candidate + Send + Sync>) -> Result<()> {
if c.tcp_type() == TcpType::Active {
log::info!("Ignoring remote candidate with tcpType active: {}", c);
return Ok(());
}
if c.candidate_type() == CandidateType::Host && c.address().ends_with(".local") {
if self.mdns_mode == MulticastDnsMode::Disabled {
log::warn!(
"remote mDNS candidate added, but mDNS is disabled: ({})",
c.address()
);
return Ok(());
}
if c.candidate_type() != CandidateType::Host {
return Err(Error::ErrAddressParseFailed);
}
let ai = Arc::clone(&self.internal);
let host_candidate = Arc::clone(c);
let mdns_conn = self.mdns_conn.clone();
tokio::spawn(async move {
if let Some(mdns_conn) = mdns_conn {
if let Ok(candidate) =
Self::resolve_and_add_multicast_candidate(mdns_conn, host_candidate).await
{
ai.add_remote_candidate(&candidate).await;
}
}
});
} else {
let ai = Arc::clone(&self.internal);
let candidate = Arc::clone(c);
tokio::spawn(async move {
ai.add_remote_candidate(&candidate).await;
});
}
Ok(())
}
pub async fn get_local_candidates(&self) -> Result<Vec<Arc<dyn Candidate + Send + Sync>>> {
let mut res = vec![];
{
let local_candidates = self.internal.local_candidates.lock().await;
for candidates in local_candidates.values() {
for candidate in candidates {
res.push(Arc::clone(candidate));
}
}
}
Ok(res)
}
pub async fn get_local_user_credentials(&self) -> (String, String) {
let ufrag_pwd = self.internal.ufrag_pwd.lock().await;
(ufrag_pwd.local_ufrag.clone(), ufrag_pwd.local_pwd.clone())
}
pub async fn get_remote_user_credentials(&self) -> (String, String) {
let ufrag_pwd = self.internal.ufrag_pwd.lock().await;
(ufrag_pwd.remote_ufrag.clone(), ufrag_pwd.remote_pwd.clone())
}
pub async fn close(&self) -> Result<()> {
if let Some(gather_candidate_cancel) = &self.gather_candidate_cancel {
gather_candidate_cancel();
}
if let UDPNetwork::Muxed(ref udp_mux) = self.udp_network {
let (ufrag, _) = self.get_local_user_credentials().await;
udp_mux.remove_conn_by_ufrag(&ufrag).await;
}
self.internal.close().await
}
pub async fn get_selected_candidate_pair(&self) -> Option<Arc<CandidatePair>> {
self.internal.agent_conn.get_selected_pair().await
}
pub async fn set_remote_credentials(
&self,
remote_ufrag: String,
remote_pwd: String,
) -> Result<()> {
self.internal
.set_remote_credentials(remote_ufrag, remote_pwd)
.await
}
pub async fn restart(&self, mut ufrag: String, mut pwd: String) -> Result<()> {
if ufrag.is_empty() {
ufrag = generate_ufrag();
}
if pwd.is_empty() {
pwd = generate_pwd();
}
if ufrag.len() * 8 < 24 {
return Err(Error::ErrLocalUfragInsufficientBits);
}
if pwd.len() * 8 < 128 {
return Err(Error::ErrLocalPwdInsufficientBits);
}
if GatheringState::from(self.gathering_state.load(Ordering::SeqCst))
== GatheringState::Gathering
{
return Err(Error::ErrRestartWhenGathering);
}
self.gathering_state
.store(GatheringState::New as u8, Ordering::SeqCst);
{
let done_tx = self.internal.done_tx.lock().await;
if done_tx.is_none() {
return Err(Error::ErrClosed);
}
}
{
let mut ufrag_pwd = self.internal.ufrag_pwd.lock().await;
ufrag_pwd.local_ufrag = ufrag;
ufrag_pwd.local_pwd = pwd;
ufrag_pwd.remote_ufrag = String::new();
ufrag_pwd.remote_pwd = String::new();
}
{
let mut pending_binding_requests = self.internal.pending_binding_requests.lock().await;
*pending_binding_requests = vec![];
}
{
let mut checklist = self.internal.agent_conn.checklist.lock().await;
*checklist = vec![];
}
self.internal.set_selected_pair(None).await;
self.internal.delete_all_candidates().await;
self.internal.start().await;
if self.internal.connection_state.load(Ordering::SeqCst) != ConnectionState::New as u8 {
self.internal
.update_connection_state(ConnectionState::Checking)
.await;
}
Ok(())
}
pub async fn gather_candidates(&self) -> Result<()> {
if self.gathering_state.load(Ordering::SeqCst) != GatheringState::New as u8 {
return Err(Error::ErrMultipleGatherAttempted);
}
{
let on_candidate_hdlr = self.internal.on_candidate_hdlr.lock().await;
if on_candidate_hdlr.is_none() {
return Err(Error::ErrNoOnCandidateHandler);
}
}
if let Some(gather_candidate_cancel) = &self.gather_candidate_cancel {
gather_candidate_cancel();
}
let params = GatherCandidatesInternalParams {
udp_network: self.udp_network.clone(),
candidate_types: self.candidate_types.clone(),
urls: self.urls.clone(),
network_types: self.network_types.clone(),
mdns_mode: self.mdns_mode,
mdns_name: self.mdns_name.clone(),
net: Arc::clone(&self.net),
interface_filter: self.interface_filter.clone(),
ext_ip_mapper: Arc::clone(&self.ext_ip_mapper),
agent_internal: Arc::clone(&self.internal),
gathering_state: Arc::clone(&self.gathering_state),
chan_candidate_tx: Arc::clone(&self.internal.chan_candidate_tx),
};
tokio::spawn(async move {
Self::gather_candidates_internal(params).await;
});
Ok(())
}
pub async fn get_candidate_pairs_stats(&self) -> Vec<CandidatePairStats> {
self.internal.get_candidate_pairs_stats().await
}
pub async fn get_local_candidates_stats(&self) -> Vec<CandidateStats> {
self.internal.get_local_candidates_stats().await
}
pub async fn get_remote_candidates_stats(&self) -> Vec<CandidateStats> {
self.internal.get_remote_candidates_stats().await
}
async fn resolve_and_add_multicast_candidate(
mdns_conn: Arc<DnsConn>,
c: Arc<dyn Candidate + Send + Sync>,
) -> Result<Arc<dyn Candidate + Send + Sync>> {
let (_close_query_signal_tx, close_query_signal_rx) = mpsc::channel(1);
let src = match mdns_conn.query(&c.address(), close_query_signal_rx).await {
Ok((_, src)) => src,
Err(err) => {
log::warn!("Failed to discover mDNS candidate {}: {}", c.address(), err);
return Err(err.into());
}
};
c.set_ip(&src.ip()).await?;
Ok(c)
}
async fn close_multicast_conn(mdns_conn: &Option<Arc<DnsConn>>) {
if let Some(conn) = mdns_conn {
if let Err(err) = conn.close().await {
log::warn!("failed to close mDNS Conn: {}", err);
}
}
}
}