use std::{
collections::HashMap,
fmt::Debug,
net::IpAddr,
sync::{Arc, Mutex, OnceLock, RwLock},
time::Duration,
};
use derive_more::{Deref, DerefMut};
pub use netdev::Interface;
pub use netwatcher::Error as WatcherError;
use netwatcher::WatchHandle;
use qbase::{
net::Family,
util::{UniqueId, UniqueIdGenerator},
};
use tokio::{
sync::mpsc::{UnboundedReceiver, UnboundedSender},
time::MissedTickBehavior,
};
use tokio_util::task::AbortOnDropHandle;
#[allow(clippy::large_enum_variant)]
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum InterfaceEvent {
Added {
device: String,
new_interface: Interface,
},
Removed {
device: String,
old_interface: Interface,
},
Changed {
device: String,
old_interface: Interface,
new_interface: Interface,
},
}
impl InterfaceEvent {
pub fn device(&self) -> &str {
match self {
InterfaceEvent::Added { device, .. } => device,
InterfaceEvent::Removed { device, .. } => device,
InterfaceEvent::Changed { device, .. } => device,
}
}
pub fn old_interface(&self) -> Option<&Interface> {
match self {
InterfaceEvent::Removed { old_interface, .. }
| InterfaceEvent::Changed { old_interface, .. } => Some(old_interface),
_ => None,
}
}
pub fn new_interface(&self) -> Option<&Interface> {
match self {
InterfaceEvent::Added { new_interface, .. }
| InterfaceEvent::Changed { new_interface, .. } => Some(new_interface),
_ => None,
}
}
}
impl InterfaceEvent {
pub fn from_update<'i>(
old_interfaces: &'i HashMap<String, Interface>,
new_interfaces: &'i HashMap<String, Interface>,
) -> impl Iterator<Item = Self> + 'i {
new_interfaces
.iter()
.filter_map(|(name, new_interface)| match old_interfaces.get(name) {
Some(old_interface) if new_interface != old_interface => {
Some(InterfaceEvent::Changed {
device: name.to_owned(),
old_interface: old_interface.clone(),
new_interface: new_interface.clone(),
})
}
None => Some(InterfaceEvent::Added {
device: name.to_owned(),
new_interface: new_interface.clone(),
}),
_ => None,
})
.chain(
old_interfaces
.iter()
.filter(|(name, ..)| !new_interfaces.contains_key(*name))
.map(|(name, old_interface)| InterfaceEvent::Removed {
device: name.to_owned(),
old_interface: old_interface.clone(),
}),
)
}
}
fn scan_interfaces() -> HashMap<String, Interface> {
netdev::get_interfaces()
.into_iter()
.map(|mut iface| {
iface.name = iface
.name
.trim_start_matches('{')
.trim_end_matches('}')
.to_string();
iface
})
.map(|iface| (iface.name.clone(), iface))
.collect()
}
type SubscribersMap = RwLock<HashMap<UniqueId, UnboundedSender<Arc<InterfaceEvent>>>>;
type InterfacesMap = RwLock<HashMap<String, Interface>>;
#[derive(Debug, Deref, DerefMut)]
pub struct InterfaceEventReceiver {
id: UniqueId,
#[deref]
#[deref_mut]
receiver: UnboundedReceiver<Arc<InterfaceEvent>>,
subscribers: Arc<SubscribersMap>,
}
impl Drop for InterfaceEventReceiver {
fn drop(&mut self) {
self.subscribers.write().unwrap().remove(&self.id);
}
}
pub struct InterfacesMonitor {
interfaces: HashMap<String, Interface>,
receiver: InterfaceEventReceiver,
}
impl InterfacesMonitor {
#[inline]
pub async fn update(&mut self) -> Option<(&HashMap<String, Interface>, Arc<InterfaceEvent>)> {
self.receiver.recv().await.map(|event| {
match event.as_ref() {
InterfaceEvent::Added {
device,
new_interface,
} => {
self.interfaces
.insert(device.clone(), new_interface.clone());
}
InterfaceEvent::Removed { device, .. } => {
self.interfaces.remove(device);
}
InterfaceEvent::Changed {
device,
new_interface,
..
} => {
self.interfaces
.insert(device.clone(), new_interface.clone());
}
}
(self.interfaces(), event)
})
}
#[inline]
pub fn try_update(&mut self) -> Option<(&HashMap<String, Interface>, Arc<InterfaceEvent>)> {
self.receiver.try_recv().ok().map(|event| {
match event.as_ref() {
InterfaceEvent::Added {
device,
new_interface,
} => {
self.interfaces
.insert(device.clone(), new_interface.clone());
}
InterfaceEvent::Removed { device, .. } => {
self.interfaces.remove(device);
}
InterfaceEvent::Changed {
device,
new_interface,
..
} => {
self.interfaces
.insert(device.clone(), new_interface.clone());
}
}
(self.interfaces(), event)
})
}
#[inline]
pub fn interfaces(&self) -> &HashMap<String, Interface> {
&self.interfaces
}
pub fn into_inner(self) -> (HashMap<String, Interface>, InterfaceEventReceiver) {
(self.interfaces, self.receiver)
}
}
#[derive(Debug)]
struct State {
interfaces: InterfacesMap,
subscrib_id_generator: UniqueIdGenerator,
subscribers: Arc<SubscribersMap>,
}
impl Default for State {
fn default() -> Self {
Self {
interfaces: RwLock::new(scan_interfaces()),
subscrib_id_generator: UniqueIdGenerator::new(),
subscribers: Arc::new(RwLock::new(HashMap::new())),
}
}
}
impl State {
fn check_network_changes(&self) {
let mut interfaces = self.interfaces.write().unwrap();
let subscribers = self.subscribers.read().unwrap();
let old_interfaces = interfaces.clone();
let new_interfaces = scan_interfaces();
for event in InterfaceEvent::from_update(&old_interfaces, &new_interfaces) {
let arc_event = Arc::new(event);
for sender in subscribers.values() {
let _ = sender.send(arc_event.clone());
}
}
*interfaces = new_interfaces.clone();
}
fn monitor(&self) -> (HashMap<String, Interface>, InterfaceEventReceiver) {
let mut subscribers = self.subscribers.write().unwrap();
let interfaces = self.interfaces.read().unwrap().clone();
let current_interfaces = interfaces;
let (tx, rx) = tokio::sync::mpsc::unbounded_channel();
let id = self.subscrib_id_generator.generate();
subscribers.insert(id, tx);
let observer = InterfaceEventReceiver {
id,
receiver: rx,
subscribers: Arc::clone(&self.subscribers),
};
(current_interfaces, observer)
}
fn event_receiver(&self) -> InterfaceEventReceiver {
let mut subscribers = self.subscribers.write().unwrap();
let (tx, rx) = tokio::sync::mpsc::unbounded_channel();
let id = self.subscrib_id_generator.generate();
subscribers.insert(id, tx);
InterfaceEventReceiver {
id,
receiver: rx,
subscribers: Arc::clone(&self.subscribers),
}
}
fn interfaces(&self) -> HashMap<String, Interface> {
self.interfaces.read().unwrap().clone()
}
fn get(&self, name: &str) -> Option<Interface> {
self.interfaces.read().unwrap().get(name).cloned()
}
}
pub struct Devices {
state: Arc<State>,
watcher: Mutex<Result<WatchHandle, WatcherError>>,
_timer: AbortOnDropHandle<()>,
}
impl Debug for Devices {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("Devices")
.field("state", &self.state)
.field("watcher", &"...")
.field("_timer", &self._timer)
.finish()
}
}
impl Devices {
pub fn global() -> &'static Devices {
static DEVICES: OnceLock<Devices> = OnceLock::new();
DEVICES.get_or_init(Self::new)
}
pub fn new() -> Self {
let state = Arc::new(State::default());
let timer = AbortOnDropHandle::new(tokio::spawn({
let state = state.clone();
async move {
let mut interval = tokio::time::interval(Duration::from_secs(5));
interval.set_missed_tick_behavior(MissedTickBehavior::Delay);
loop {
interval.tick().await;
state.check_network_changes();
}
}
}));
let watcher = netwatcher::watch_interfaces({
let state = state.clone();
move |_update| {
state.check_network_changes();
}
});
if let Err(initial_watcher_error) = &watcher {
tracing::warn!(target: "interface", "failed to start interfaces watcher: {initial_watcher_error}");
}
Self {
state,
_timer: timer,
watcher: watcher.into(),
}
}
#[inline]
pub fn restart_watcher(&self) -> Result<(), WatcherError> {
let new_watcher = netwatcher::watch_interfaces({
let state = self.state.clone();
move |_update| {
state.check_network_changes();
}
})?;
*self.watcher.lock().unwrap() = Ok(new_watcher);
Ok(())
}
#[inline]
pub fn on_interface_changed(&self) {
self.state.check_network_changes();
}
#[inline]
pub fn monitor(&self) -> InterfacesMonitor {
let (interfaces, receiver) = self.state.monitor();
InterfacesMonitor {
interfaces,
receiver,
}
}
#[inline]
pub fn event_receiver(&self) -> InterfaceEventReceiver {
self.state.event_receiver()
}
#[inline]
pub fn interfaces(&self) -> HashMap<String, Interface> {
self.state.interfaces()
}
pub fn get(&self, name: &str) -> Option<Interface> {
self.state.get(name)
}
pub fn resolve(&self, device: &str, family: Family) -> Option<IpAddr> {
let interface = self.get(device)?;
match family {
Family::V4 => interface
.ipv4
.first()
.map(|ipnet| ipnet.addr())
.map(IpAddr::V4),
Family::V6 => interface
.ipv6
.iter()
.map(|ipnet| ipnet.addr())
.find(|ip| !matches!(ip.octets(), [0xfe, 0x80, ..]))
.map(IpAddr::V6),
}
}
}
impl Default for Devices {
#[inline]
fn default() -> Self {
Self::new()
}
}