use crate::{buffer::Ring, device::DeviceHandle, protocol::parse_session_reply};
use std::{
sync::{
Arc, Mutex,
atomic::{AtomicBool, AtomicU64, Ordering},
},
thread::JoinHandle,
};
use winptap_core::*;
static NEXT: AtomicU64 = AtomicU64::new(1);
pub(crate) struct NativeSession {
handle: DeviceHandle,
id: u64,
stream: u64,
ring: Arc<Mutex<Ring>>,
reader: Option<JoinHandle<()>>,
queue: Arc<PacketQueue>,
config: Config,
stop: Arc<AtomicBool>,
started: bool,
stopped: bool,
}
impl NativeSession {
pub fn open(config: Config) -> Result<Self> {
if config
.application_filter
.as_ref()
.is_some_and(|f| f.direction == Some(Direction::Transmit))
{
return Err(Error::InvalidConfig("native backend is receive-only"));
}
if config
.capture_filter
.as_ref()
.is_some_and(|f| f.direction == Some(Direction::Transmit))
{
return Err(Error::InvalidConfig("native backend is receive-only"));
}
let handle = DeviceHandle::open()?;
if let Some(f) = &config.capture_filter {
crate::filter::encode(0, f)?;
}
if let Some(d) = &config.device {
if d.backend != Backend::NativeIoctl {
return Err(Error::InvalidConfig(
"native capture needs a native component identity",
));
}
if !crate::discovery::enumerate(&handle)?
.iter()
.any(|v| v.id == d.id && v.name == d.name)
{
return Err(Error::InvalidConfig("native component disappeared"));
}
}
let ring = Ring::new(config.ring_multiplier)?;
let mut input = [0u8; 512];
let name = format!(
"winptap-native-{}-{}",
std::process::id(),
NEXT.fetch_add(1, Ordering::Relaxed)
);
for (i, c) in name.encode_utf16().enumerate() {
input[i * 2..i * 2 + 2].copy_from_slice(&c.to_le_bytes());
}
let mut output = [0u8; 528];
let returned = handle.ioctl(crate::ioctl::Control::CreateSession, &input, &mut output)?;
let id = parse_session_reply(&output[..returned])?.identifier;
let mut result = Self {
handle,
id,
stream: 0,
ring: Arc::new(Mutex::new(ring)),
reader: None,
queue: PacketQueue::new(config.queue_capacity, config.overflow),
config,
stop: Arc::new(AtomicBool::new(false)),
started: false,
stopped: false,
};
if let Some(f) = &result.config.capture_filter {
result.handle.ioctl(
crate::ioctl::Control::AddConstraint,
&crate::filter::encode(id, f)?,
&mut [],
)?;
}
if let Some(d) = &result.config.device {
let mut selection = [0u8; 20];
selection[..8].copy_from_slice(&id.to_le_bytes());
selection[8..12].copy_from_slice(&3u32.to_le_bytes());
selection[12..14].copy_from_slice(&1u16.to_le_bytes());
selection[16..20].copy_from_slice(&d.id.to_le_bytes());
result
.handle
.ioctl(crate::ioctl::Control::SelectComponents, &selection, &mut [])?;
}
let ring = result.ring.lock().unwrap_or_else(|p| p.into_inner());
let mut attach = [0u8; 40];
attach[..8].copy_from_slice(&id.to_le_bytes());
attach[8..16].copy_from_slice(&ring.packets.address().to_le_bytes());
attach[16..20].copy_from_slice(&(ring.packets.size as u32).to_le_bytes());
attach[24..32].copy_from_slice(&ring.control.address().to_le_bytes());
attach[32..36].copy_from_slice(&(ring.control.size as u32).to_le_bytes());
attach[36..38].copy_from_slice(&result.config.snaplen.to_le_bytes());
let mut output = [0u8; 8];
let returned =
result
.handle
.ioctl(crate::ioctl::Control::AttachStream, &attach, &mut output)?;
if returned != 8 {
return Err(Error::InvalidData("stream identifier size"));
}
result.stream = u64::from_le_bytes(output);
drop(ring);
Ok(result)
}
}
impl Session for NativeSession {
fn start(&mut self) -> Result<()> {
if self.started {
return Err(Error::InvalidState);
}
self.queue.reopen()?;
self.stop.store(false, Ordering::Release);
self.handle.ioctl(
crate::ioctl::Control::Activate,
&self.id.to_le_bytes(),
&mut [],
)?;
self.started = true;
self.stopped = false;
let shared_ring = self.ring.clone();
let stop = self.stop.clone();
let queue = self.queue.clone();
let config = self.config.clone();
self.reader = Some(
std::thread::Builder::new()
.name("winptap-native-reader".into())
.spawn(move || {
let outcome = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
let mut ring = shared_ring.lock().unwrap_or_else(|p| p.into_inner());
while !stop.load(Ordering::Acquire) && !queue.is_closed() {
let bytes = match ring.read() {
Ok(Some(b)) => b,
Ok(None) => {
std::thread::sleep(std::time::Duration::from_millis(1));
continue;
}
Err(e) => {
queue.close(Err(e));
break;
}
};
if u32::from_le_bytes(bytes[8..12].try_into().unwrap()) != 40 {
queue.close(Err(Error::InvalidData("native metadata version")));
break;
}
let missed = u32::from_le_bytes(bytes[12..16].try_into().unwrap());
queue.update_stats(|s| s.missed_writes += u64::from(missed));
let packet = match winptap_core::wire::decode_stream(
&bytes,
24,
64,
(bytes.len() - 64) as u32,
config.snaplen,
Backend::NativeIoctl,
)
.and_then(|p| {
p.with_original_len(u32::from_le_bytes(
bytes[..4].try_into().unwrap(),
))
}) {
Ok(p) => p,
Err(_) => {
queue.update_stats(|s| s.parse_errors += 1);
continue;
}
};
let m = packet.metadata();
queue.update_stats(|s| {
s.received += 1;
if m.truncation == Truncation::CaptureLimitReached {
s.capture_limit_reached += 1;
}
if m.truncation == Truncation::Known {
s.known_truncations += 1;
}
});
let component_ok = match config.duplicates {
DuplicatePolicy::PreserveAll => true,
DuplicatePolicy::Component(id) => m.component_id == id,
};
if m.direction != Direction::Receive
|| !component_ok
|| config.link_type.is_some_and(|v| v != m.link_type)
|| config
.capture_filter
.as_ref()
.is_some_and(|f| !f.matches(&packet))
|| config
.application_filter
.as_ref()
.is_some_and(|f| !f.matches(&packet))
{
queue.update_stats(|s| s.filtered += 1);
continue;
}
queue.push(packet);
}
}));
if outcome.is_err() {
queue.close(Err(Error::StreamFailed(1359)));
}
})
.map_err(|_| Error::Windows {
operation: "spawn native reader",
code: 8,
})?,
);
Ok(())
}
fn stop(&mut self) -> Result<()> {
if self.stopped {
return Ok(());
}
if self.started {
self.handle.ioctl(
crate::ioctl::Control::Deactivate,
&self.id.to_le_bytes(),
&mut [],
)?;
}
self.stop.store(true, Ordering::Release);
if let Some(reader) = self.reader.take() {
reader.join().map_err(|_| Error::StreamFailed(1359))?;
}
self.started = false;
self.stopped = true;
self.queue.close(Ok(()));
Ok(())
}
fn queue(&self) -> Arc<PacketQueue> {
self.queue.clone()
}
}
impl Drop for NativeSession {
fn drop(&mut self) {
let _ = self.stop();
self.stop.store(true, Ordering::Release);
if let Some(reader) = self.reader.take() {
let _ = reader.join();
}
if self.stream != 0 {
let _ = self.handle.ioctl(
crate::ioctl::Control::DetachStream,
&self.stream.to_le_bytes(),
&mut [],
);
}
let _ = self.handle.ioctl(
crate::ioctl::Control::DeleteSession,
&self.id.to_le_bytes(),
&mut [],
);
}
}