feat: introduce improved capture device init #22

Author: SkuldNorniern

src/net/capture.rs

@@ -0,0 +1,83 @@
+use pcap::{Capture, Active, Device,Error as PcapError,Address};
+use std::time::Instant;
+
+#[derive(Debug)]
+pub enum CaptureError {
+    Cap(PcapError),
+    Other(String),
+    DeviceNotFound(String),
+    InitializationError(String),
+    InvalidDeviceIndex(String),
+}
+
+impl From<pcap::Error> for CaptureError {
+    fn from(err: PcapError) -> Self {
+        CaptureError::Cap(err)
+    }
+}
+
+impl From<String> for CaptureError {
+    fn from(err: String) -> Self {
+        CaptureError::Other(err)
+    }
+}
+
+pub struct CaptureDevice{
+    pub name: String,
+    pub desc: String,
+    pub address: Vec<Address>,
+    pub capture: Capture<Active>,
+}
+
+impl CaptureDevice{
+    pub fn new(device: Device) -> Result<CaptureDevice, CaptureError> {
+        let capture = initialize_capture(device.clone())?;
+
+        Ok(CaptureDevice {
+            name: device.name,
+            desc: device.desc.as_deref().unwrap_or("").to_string(),
+            address: device.addresses,
+            capture,
+        })
+    }
+}
+pub fn list_devices() -> Result<Vec<Device>, CaptureError> {
+    Ok(Device::list().map_err(CaptureError::Cap)?)
+}
+pub fn find_device(identifier: &str) -> Result<Device, CaptureError> {
+    let start = Instant::now();
+    println!("Requested Device: {}", identifier);
+
+    let devices = list_devices()?;
+
+    if let Ok(index) = identifier.parse::<usize>() {
+        if let Some(device) = devices.get(index) {
+            let duration = start.elapsed();
+            println!("Device {} captured in {:?}", device.name, duration);
+            return Ok(device.clone());
+        } else {
+            return Err(CaptureError::InvalidDeviceIndex(identifier.to_string()));
+        }
+    }
+
+    for device in devices {
+        if device.name == identifier {
+            let duration = start.elapsed();
+            println!("{} device captured in {:?}", identifier, duration);
+            return Ok(device);
+        }
+    }
+
+    Err(CaptureError::DeviceNotFound(identifier.to_string()))
+}
+
+fn initialize_capture(device: Device) -> Result<Capture<Active>, CaptureError> {
+    Capture::from_device(device)
+        .map_err(CaptureError::Cap)?
+        .promisc(true)
+        .snaplen(1024)
+        .timeout(60000)
+        .immediate_mode(true)
+        .open()
+        .map_err(|_| CaptureError::InitializationError("Capture initialization error".into()))
+}