rns_net/interface/
mod.rs

1//! Network interface abstractions.
2
3#[cfg(feature = "iface-auto")]
4pub mod auto;
5#[cfg(feature = "iface-backbone")]
6pub mod backbone;
7#[cfg(feature = "iface-i2p")]
8pub mod i2p;
9#[cfg(feature = "iface-kiss")]
10pub mod kiss_iface;
11#[cfg(feature = "iface-local")]
12pub mod local;
13#[cfg(feature = "iface-pipe")]
14pub mod pipe;
15pub mod registry;
16#[cfg(feature = "iface-rnode")]
17pub mod rnode;
18#[cfg(feature = "iface-serial")]
19pub mod serial_iface;
20#[cfg(feature = "iface-tcp")]
21pub mod tcp;
22#[cfg(feature = "iface-tcp")]
23pub mod tcp_server;
24#[cfg(feature = "iface-udp")]
25pub mod udp;
26
27use std::any::Any;
28use std::collections::HashMap;
29use std::io;
30use std::sync::atomic::{AtomicBool, AtomicU64, AtomicUsize, Ordering};
31use std::sync::mpsc::{sync_channel, SyncSender, TrySendError};
32use std::sync::Arc;
33use std::thread;
34use std::time::{Duration, Instant};
35
36use crate::event::EventSender;
37use crate::ifac::IfacState;
38use rns_core::transport::types::{InterfaceId, InterfaceInfo};
39
40/// Bind a socket to a specific network interface using `SO_BINDTODEVICE`.
41///
42/// Requires `CAP_NET_RAW` or root on Linux.
43#[cfg(target_os = "linux")]
44pub fn bind_to_device(fd: std::os::unix::io::RawFd, device: &str) -> io::Result<()> {
45    let dev_bytes = device.as_bytes();
46    if dev_bytes.len() >= libc::IFNAMSIZ {
47        return Err(io::Error::new(
48            io::ErrorKind::InvalidInput,
49            format!("device name too long: {}", device),
50        ));
51    }
52    let ret = unsafe {
53        libc::setsockopt(
54            fd,
55            libc::SOL_SOCKET,
56            libc::SO_BINDTODEVICE,
57            dev_bytes.as_ptr() as *const libc::c_void,
58            dev_bytes.len() as libc::socklen_t,
59        )
60    };
61    if ret != 0 {
62        return Err(io::Error::last_os_error());
63    }
64    Ok(())
65}
66
67/// Writable end of an interface. Held by the driver.
68///
69/// Each implementation wraps a socket + framing.
70pub trait Writer: Send {
71    fn send_frame(&mut self, data: &[u8]) -> io::Result<()>;
72}
73
74pub const DEFAULT_ASYNC_WRITER_QUEUE_CAPACITY: usize = 256;
75
76#[derive(Clone, Default)]
77pub struct ListenerControl {
78    stop: Arc<AtomicBool>,
79}
80
81impl ListenerControl {
82    pub fn new() -> Self {
83        Self {
84            stop: Arc::new(AtomicBool::new(false)),
85        }
86    }
87
88    pub fn request_stop(&self) {
89        self.stop.store(true, Ordering::Relaxed);
90    }
91
92    pub fn should_stop(&self) -> bool {
93        self.stop.load(Ordering::Relaxed)
94    }
95}
96
97#[derive(Clone, Default)]
98pub struct AsyncWriterMetrics {
99    queued_frames: Arc<AtomicUsize>,
100    worker_alive: Arc<AtomicBool>,
101}
102
103impl AsyncWriterMetrics {
104    pub fn queued_frames(&self) -> usize {
105        self.queued_frames.load(Ordering::Relaxed)
106    }
107
108    pub fn worker_alive(&self) -> bool {
109        self.worker_alive.load(Ordering::Relaxed)
110    }
111}
112
113struct AsyncWriter {
114    tx: SyncSender<Vec<u8>>,
115    metrics: AsyncWriterMetrics,
116}
117
118impl Writer for AsyncWriter {
119    fn send_frame(&mut self, data: &[u8]) -> io::Result<()> {
120        if !self.metrics.worker_alive() {
121            return Err(io::Error::new(
122                io::ErrorKind::BrokenPipe,
123                "interface writer worker is offline",
124            ));
125        }
126
127        match self.tx.try_send(data.to_vec()) {
128            Ok(()) => {
129                self.metrics.queued_frames.fetch_add(1, Ordering::Relaxed);
130                Ok(())
131            }
132            Err(TrySendError::Full(_)) => Err(io::Error::new(
133                io::ErrorKind::WouldBlock,
134                "interface writer queue is full",
135            )),
136            Err(TrySendError::Disconnected(_)) => {
137                self.metrics
138                    .worker_alive
139                    .store(false, Ordering::Relaxed);
140                Err(io::Error::new(
141                    io::ErrorKind::BrokenPipe,
142                    "interface writer worker disconnected",
143                ))
144            }
145        }
146    }
147}
148
149pub fn wrap_async_writer(
150    writer: Box<dyn Writer>,
151    interface_id: InterfaceId,
152    interface_name: &str,
153    event_tx: EventSender,
154    queue_capacity: usize,
155) -> (Box<dyn Writer>, AsyncWriterMetrics) {
156    let (tx, rx) = sync_channel::<Vec<u8>>(queue_capacity.max(1));
157    let metrics = AsyncWriterMetrics {
158        queued_frames: Arc::new(AtomicUsize::new(0)),
159        worker_alive: Arc::new(AtomicBool::new(true)),
160    };
161    let metrics_thread = metrics.clone();
162    let name = interface_name.to_string();
163
164    thread::Builder::new()
165        .name(format!("iface-writer-{}", interface_id.0))
166        .spawn(move || {
167            async_writer_loop(writer, rx, interface_id, name, event_tx, metrics_thread)
168        })
169        .expect("failed to spawn interface writer thread");
170
171    (
172        Box::new(AsyncWriter {
173            tx,
174            metrics: metrics.clone(),
175        }),
176        metrics,
177    )
178}
179
180fn async_writer_loop(
181    mut writer: Box<dyn Writer>,
182    rx: std::sync::mpsc::Receiver<Vec<u8>>,
183    interface_id: InterfaceId,
184    interface_name: String,
185    event_tx: EventSender,
186    metrics: AsyncWriterMetrics,
187) {
188    while let Ok(frame) = rx.recv() {
189        metrics.queued_frames.fetch_sub(1, Ordering::Relaxed);
190        if let Err(err) = writer.send_frame(&frame) {
191            metrics.worker_alive.store(false, Ordering::Relaxed);
192            log::warn!(
193                "[{}:{}] async writer exiting after send failure: {}",
194                interface_name,
195                interface_id.0,
196                err
197            );
198            let _ = event_tx.send(crate::event::Event::InterfaceDown(interface_id));
199            return;
200        }
201    }
202
203    metrics.worker_alive.store(false, Ordering::Relaxed);
204}
205
206pub use crate::common::interface_stats::{InterfaceStats, ANNOUNCE_SAMPLE_MAX};
207
208use crate::common::management::InterfaceStatusView;
209
210/// Everything the driver tracks per interface.
211pub struct InterfaceEntry {
212    pub id: InterfaceId,
213    pub info: InterfaceInfo,
214    pub writer: Box<dyn Writer>,
215    pub async_writer_metrics: Option<AsyncWriterMetrics>,
216    /// Administrative enable/disable state.
217    pub enabled: bool,
218    pub online: bool,
219    /// True for dynamically spawned interfaces (e.g. TCP server clients).
220    /// These are fully removed on InterfaceDown rather than just marked offline.
221    pub dynamic: bool,
222    /// IFAC state for this interface, if access codes are enabled.
223    pub ifac: Option<IfacState>,
224    /// Traffic statistics.
225    pub stats: InterfaceStats,
226    /// Human-readable interface type string (e.g. "TCPClientInterface").
227    pub interface_type: String,
228    /// Next time a send should be retried after a transient WouldBlock.
229    pub send_retry_at: Option<Instant>,
230    /// Current retry backoff for transient send failures.
231    pub send_retry_backoff: Duration,
232}
233
234/// Result of starting an interface via a factory.
235pub enum StartResult {
236    /// One writer, registered immediately (TcpClient, Udp, Serial, etc.)
237    Simple {
238        id: InterfaceId,
239        info: InterfaceInfo,
240        writer: Box<dyn Writer>,
241        interface_type_name: String,
242    },
243    /// Spawns a listener; dynamic interfaces arrive via Event::InterfaceUp (TcpServer, Auto, I2P, etc.)
244    Listener { control: Option<ListenerControl> },
245    /// Multiple subinterfaces from one config (RNode).
246    Multi(Vec<SubInterface>),
247}
248
249/// A single subinterface returned from a multi-interface factory.
250pub struct SubInterface {
251    pub id: InterfaceId,
252    pub info: InterfaceInfo,
253    pub writer: Box<dyn Writer>,
254    pub interface_type_name: String,
255}
256
257/// Context passed to [`InterfaceFactory::start()`].
258pub struct StartContext {
259    pub tx: EventSender,
260    pub next_dynamic_id: Arc<AtomicU64>,
261    pub mode: u8,
262}
263
264/// Opaque interface config data. Each factory downcasts to its concrete type.
265pub trait InterfaceConfigData: Send + Any {
266    fn as_any(&self) -> &dyn Any;
267    fn into_any(self: Box<Self>) -> Box<dyn Any>;
268}
269
270impl<T: Send + 'static> InterfaceConfigData for T {
271    fn as_any(&self) -> &dyn Any {
272        self
273    }
274
275    fn into_any(self: Box<Self>) -> Box<dyn Any> {
276        self
277    }
278}
279
280/// Factory that can parse config and start an interface type.
281pub trait InterfaceFactory: Send + Sync {
282    /// Config-file type name, e.g. "TCPClientInterface".
283    fn type_name(&self) -> &str;
284
285    /// Default IFAC size (bytes). 8 for serial/kiss/rnode, 16 for others.
286    fn default_ifac_size(&self) -> usize {
287        16
288    }
289
290    /// Parse from key-value params (config file or external).
291    fn parse_config(
292        &self,
293        name: &str,
294        id: InterfaceId,
295        params: &HashMap<String, String>,
296    ) -> Result<Box<dyn InterfaceConfigData>, String>;
297
298    /// Start the interface from parsed config.
299    fn start(
300        &self,
301        config: Box<dyn InterfaceConfigData>,
302        ctx: StartContext,
303    ) -> io::Result<StartResult>;
304}
305
306impl InterfaceStatusView for InterfaceEntry {
307    fn id(&self) -> InterfaceId {
308        self.id
309    }
310    fn info(&self) -> &InterfaceInfo {
311        &self.info
312    }
313    fn online(&self) -> bool {
314        self.online
315    }
316    fn stats(&self) -> &InterfaceStats {
317        &self.stats
318    }
319}
320
321#[cfg(test)]
322mod tests {
323    use super::*;
324    use crate::event::Event;
325    use rns_core::constants;
326    use std::sync::mpsc;
327
328    struct MockWriter {
329        sent: Vec<Vec<u8>>,
330    }
331
332    impl MockWriter {
333        fn new() -> Self {
334            MockWriter { sent: Vec::new() }
335        }
336    }
337
338    impl Writer for MockWriter {
339        fn send_frame(&mut self, data: &[u8]) -> io::Result<()> {
340            self.sent.push(data.to_vec());
341            Ok(())
342        }
343    }
344
345    #[test]
346    fn interface_entry_construction() {
347        let entry = InterfaceEntry {
348            id: InterfaceId(1),
349            info: InterfaceInfo {
350                id: InterfaceId(1),
351                name: String::new(),
352                mode: constants::MODE_FULL,
353                out_capable: true,
354                in_capable: true,
355                bitrate: None,
356                announce_rate_target: None,
357                announce_rate_grace: 0,
358                announce_rate_penalty: 0.0,
359                announce_cap: constants::ANNOUNCE_CAP,
360                is_local_client: false,
361                wants_tunnel: false,
362                tunnel_id: None,
363                mtu: constants::MTU as u32,
364                ia_freq: 0.0,
365                started: 0.0,
366                ingress_control: false,
367            },
368            writer: Box::new(MockWriter::new()),
369            async_writer_metrics: None,
370            enabled: true,
371            online: false,
372            dynamic: false,
373            ifac: None,
374            stats: InterfaceStats::default(),
375            interface_type: String::new(),
376            send_retry_at: None,
377            send_retry_backoff: Duration::ZERO,
378        };
379        assert_eq!(entry.id, InterfaceId(1));
380        assert!(!entry.online);
381        assert!(!entry.dynamic);
382    }
383
384    #[test]
385    fn mock_writer_captures_bytes() {
386        let mut writer = MockWriter::new();
387        writer.send_frame(b"hello").unwrap();
388        writer.send_frame(b"world").unwrap();
389        assert_eq!(writer.sent.len(), 2);
390        assert_eq!(writer.sent[0], b"hello");
391        assert_eq!(writer.sent[1], b"world");
392    }
393
394    #[test]
395    fn writer_send_frame_produces_output() {
396        let mut writer = MockWriter::new();
397        let data = vec![0x01, 0x02, 0x03];
398        writer.send_frame(&data).unwrap();
399        assert_eq!(writer.sent[0], data);
400    }
401
402    struct BlockingWriter {
403        entered_tx: mpsc::Sender<()>,
404        release_rx: mpsc::Receiver<()>,
405    }
406
407    impl Writer for BlockingWriter {
408        fn send_frame(&mut self, _data: &[u8]) -> io::Result<()> {
409            let _ = self.entered_tx.send(());
410            let _ = self.release_rx.recv();
411            Ok(())
412        }
413    }
414
415    struct FailingWriter;
416
417    impl Writer for FailingWriter {
418        fn send_frame(&mut self, _data: &[u8]) -> io::Result<()> {
419            Err(io::Error::new(io::ErrorKind::BrokenPipe, "boom"))
420        }
421    }
422
423    #[test]
424    fn async_writer_returns_wouldblock_when_queue_is_full() {
425        let (event_tx, _event_rx) = crate::event::channel();
426        let (entered_tx, entered_rx) = mpsc::channel();
427        let (release_tx, release_rx) = mpsc::channel();
428        let (mut writer, metrics) = wrap_async_writer(
429            Box::new(BlockingWriter {
430                entered_tx,
431                release_rx,
432            }),
433            InterfaceId(7),
434            "test",
435            event_tx,
436            1,
437        );
438
439        writer.send_frame(&[1]).unwrap();
440        entered_rx.recv_timeout(Duration::from_secs(1)).unwrap();
441        writer.send_frame(&[2]).unwrap();
442        assert_eq!(metrics.queued_frames(), 1);
443        let err = writer.send_frame(&[3]).unwrap_err();
444        assert_eq!(err.kind(), io::ErrorKind::WouldBlock);
445
446        let _ = release_tx.send(());
447    }
448
449    #[test]
450    fn async_writer_reports_interface_down_after_worker_failure() {
451        let (event_tx, event_rx) = crate::event::channel();
452        let (mut writer, metrics) =
453            wrap_async_writer(Box::new(FailingWriter), InterfaceId(9), "fail", event_tx, 2);
454
455        writer.send_frame(&[1]).unwrap();
456        let event = event_rx.recv_timeout(Duration::from_secs(1)).unwrap();
457        assert!(matches!(event, Event::InterfaceDown(InterfaceId(9))));
458        assert!(!metrics.worker_alive());
459    }
460}
rns_net/interface/mod.rs

rns_net/interface/
mod.rs
