refactor: Move sniffer to own module

src/radio.rs

@@ -0,0 +1,98 @@
+//! IEEE 802.11p C-ITS Capture with ESP32-C5
+
+// -----------------------------
+// missing interface definitions
+// -----------------------------
+
+use alloc::format;
+use alloc::string::String;
+
+use esp_radio::wifi::sniffer;
+
+pub type Channel = core::ffi::c_int;
+
+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
+    unsafe fn phy_change_channel(
+        primary: Channel,
+        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
+    unsafe fn phy_11p_set(enable: u8, zero: u8);
+}
+
+/// Enum values for `wifi_promiscuous_pkt_type_t` used in `esp_radio::wifi::sniffer::PromiscuousPkt::frame_type`
+///
+/// Original value is actually `core::ffi::c_uint`, but that can't be used in `#[repr()]` attributes,
+/// so we're using `u8` as the smallest suitable type here that can be casted to a bigger type.
+#[repr(u8)]
+#[derive(Debug, Clone, Copy)]
+#[allow(dead_code)]
+pub(crate) enum PromiscuousPktType {
+    /// 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 PromiscuousPktType {
+    #[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 {
+        core::ffi::c_uint::from(self.as_repr())
+    }
+
+    /// Determines if
+    pub fn matches(self, frame_type: core::ffi::c_uint) -> bool {
+        self.as_frame_type() == frame_type
+    }
+}
+
+/// Configure WiFi Sniffer to a certain 802.11p channel
+pub fn setup_wifi_sniffer(
+    channel: Channel,
+    sniffer: &mut sniffer::Sniffer,
+    callback: fn(sniffer::PromiscuousPkt<'_>),
+) -> Result<(), String> {
+    sniffer
+        .set_promiscuous_mode(true)
+        .map_err(|err| format!("Failed to enable promiscuous mode: {err:?}"))?;
+
+    sniffer.set_receive_cb(callback);
+
+    // convert channel number to frequency in MHz
+    let primary = 5000 + (channel * 5);
+
+    unsafe {
+        phy_11p_set(1, 0);
+        match phy_change_channel(primary, 1, 0, 0) {
+            0 => Ok(()),
+            ret => Err(format!("Failed to change channel: {ret}")),
+        }
+    }
+}