feat: Run a 802.11p sniffer

Cargo.toml

@@ -36,6 +36,7 @@ esp-radio = { version = "0.18.0", features = [
   "log-04",
   "unstable",
   "wifi",
+  "sniffer",
 ] }
 
 

src/bin/main.rs

@@ -10,12 +10,66 @@
 use esp_backtrace as _;
 use esp_hal::clock::CpuClock;
 use esp_hal::main;
-use esp_hal::time::{Duration, Instant};
 use esp_hal::timer::timg::TimerGroup;
-use log::info;
+use log::{debug, error, info, warn};
 
 extern crate alloc;
 
+const WIFI_CHANNEL: core::ffi::c_int = 180;
+
+unsafe extern "C" {
+    /// Changes the 802.11 PHY channel
+    ///
+    /// C function signature: `void phy_change_channel(int,int,int,int)`
+    ///
+    /// Options:
+    /// - `primary`: Channel frequency in MHz
+    /// - `ignored1`: Ignored (set to 1)
+    /// - `ignored2`: Ignored (set to 0)
+    /// - `ht_mode`: Probably HT mode
+    pub unsafe fn phy_change_channel(
+        primary: core::ffi::c_int,
+        ignored1: core::ffi::c_int,
+        ignored2: core::ffi::c_int,
+        ht_mode: core::ffi::c_int,
+    ) -> core::ffi::c_int;
+
+    /// Enables 802.11p mode on the ESP32-C5
+    ///
+    /// C function signature: `void phy_11p_set(int,int)`
+    ///
+    /// Options:
+    /// - `enable`: Boolean option to enable 802.11p mode
+    /// - `zero`: Unknown, but need to be zero
+    pub unsafe fn phy_11p_set(enable: u8, zero: u8);
+}
+
+#[repr(u8)]
+#[derive(Debug)]
+#[allow(dead_code)]
+enum EspWifiPromiscuousPktType {
+    /// Management frame, indicates 'buf' argument is wifi_promiscuous_pkt_t
+    MGMT = 0,
+    /// Control frame, indicates 'buf' argument is wifi_promiscuous_pkt_t
+    CTRL = 1,
+    /// Data frame, indicates 'buf' argument is wifi_promiscuous_pkt_t
+    DATA = 2,
+    /// Other type, such as MIMO etc. 'buf' argument is wifi_promiscuous_pkt_t but the payload is zero length.
+    MISC = 3,
+}
+
+impl EspWifiPromiscuousPktType {
+    #[allow(dead_code)]
+    pub fn as_repr(self) -> u8 {
+        self as u8
+    }
+
+    /// Converts to underlying type of `wifi_promiscuous_pkt_type_t` (used by `esp_radio::wifi::sniffer::PromiscuousPkt::frame_type`)
+    pub fn as_frame_type(self) -> core::ffi::c_uint {
+        (self as u8) as core::ffi::c_uint
+    }
+}
+
 // This creates a default app-descriptor required by the esp-idf bootloader.
 // For more information see: <https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/system/app_image_format.html#application-description>
 esp_bootloader_esp_idf::esp_app_desc!();
@@ -50,15 +104,45 @@ fn main() -> ! {
     let sw_interrupt =
         esp_hal::interrupt::software::SoftwareInterruptControl::new(peripherals.SW_INTERRUPT);
     esp_rtos::start(timg0.timer0, sw_interrupt.software_interrupt0);
-    let (mut _wifi_controller, _interfaces) =
-        esp_radio::wifi::new(peripherals.WIFI, Default::default())
+
+    let (_wifi_controller, interfaces) = esp_radio::wifi::new(
+        peripherals.WIFI,
+        esp_radio::wifi::ControllerConfig::default(),
+    )
     .expect("Failed to initialize Wi-Fi controller");
 
-    loop {
-        info!("Hello world!");
-        let delay_start = Instant::now();
-        while delay_start.elapsed() < Duration::from_millis(500) {}
+    let mut sniffer = interfaces.sniffer;
+    sniffer
+        .set_promiscuous_mode(true)
+        .expect("Failed to enable promiscuous mode");
+
+    sniffer.set_receive_cb(|packet| {
+        // Ignore frames with errors and non-data frames
+        if packet.rx_cntl.rx_state != 0 {
+            warn!("Received frame has RX error: {}", packet.rx_cntl.rx_state);
+            return;
+        }
+        if packet.frame_type != EspWifiPromiscuousPktType::DATA.as_frame_type() {
+            debug!("Received frame is not a DATA frame: {}", packet.frame_type);
+            return;
         }
 
-    // for inspiration have a look at the examples at https://github.com/esp-rs/esp-hal/tree/esp-hal-v1.1.0/examples
+        // TODO: handle 802.11 frame
+        info!("Received frame with {} bytes", packet.len);
+    });
+
+    unsafe {
+        phy_11p_set(1, 0);
+        match phy_change_channel(5000 + (WIFI_CHANNEL * 5), 1, 0, 0) {
+            0 => {}
+            ret => {
+                error!("ERROR: Failed to change channel: {ret}");
+            }
+        }
+    }
+    info!("WiFi promiscuous mode on channel {WIFI_CHANNEL} running");
+
+    loop {
+        // nothing to do here, all data is handled in RX callback for now
+    }
 }