Add channel index handling to NimBLEAdvertisedDevice and related structures

- Introduced m_channelIndex in NimBLEAdvertisedDevice to store the primary advertising channel.
- Implemented getChannel() method to retrieve the advertising channel.
- Updated setChannelIndex() method for setting the channel index.
- Modified handleGapEvent() in NimBLEScan to set the channel index from the discovery event.
- Added channel_index field to ble_gap_ext_disc_desc and ble_gap_disc_desc structures.
- Enhanced ble_hs_hci_evt_le_adv_rpt() to handle channel index in advertising reports.

Author: DTTerastar

src/NimBLEAdvertisedDevice.cpp

@@ -36,6 +36,7 @@ NimBLEAdvertisedDevice::NimBLEAdvertisedDevice() :
     m_callbackSent     = false;
     m_timestamp        = 0;
     m_advLength        = 0;
+    m_channelIndex     = 0xFF;
 } // NimBLEAdvertisedDevice
 
 
@@ -823,6 +824,19 @@ time_t NimBLEAdvertisedDevice::getTimestamp() {
 } // getTimestamp
 
 
+/**
+ * @brief Get the primary advertising channel.
+ * @return The advertising channel (37, 38, or 39) when available, or 0xFF when unknown.
+ */
+uint8_t NimBLEAdvertisedDevice::getChannel() {
+    // Map controller channel index (0-2) to BLE advertising channels (37-39)
+    if (m_channelIndex <= 2) {
+        return 37 + m_channelIndex;
+    }
+    return 0xFF;
+} // getChannel
+
+
 /**
  * @brief Get the length of the payload advertised by the device.
  * @return The size of the payload in bytes.

src/NimBLEAdvertisedDevice.h

@@ -38,6 +38,9 @@ class NimBLEScan;
  *
  * When we perform a %BLE scan, the result will be a set of devices that are advertising.  This
  * class provides a model of a detected device.
+ *
+ * The getChannel() method returns the primary advertising channel (37, 38, or 39) on which the
+ * advertisement was received, or 0xFF if the channel information is not available from the controller.
  */
 class NimBLEAdvertisedDevice {
 public:
@@ -120,6 +123,7 @@ class NimBLEAdvertisedDevice {
     size_t          getPayloadLength();
     uint8_t         getAddressType();
     time_t          getTimestamp();
+    uint8_t         getChannel();
     bool            isAdvertisingService(const NimBLEUUID &uuid);
     bool            haveAppearance();
     bool            haveManufacturerData();
@@ -149,6 +153,7 @@ class NimBLEAdvertisedDevice {
     void    setAdvType(uint8_t advType, bool isLegacyAdv);
     void    setPayload(const uint8_t *payload, uint8_t length, bool append);
     void    setRSSI(int rssi);
+    void    setChannelIndex(uint8_t channel)   { m_channelIndex = channel; }
 #if CONFIG_BT_NIMBLE_EXT_ADV
     void    setSetId(uint8_t sid)              { m_sid = sid; }
     void    setPrimaryPhy(uint8_t phy)         { m_primPhy = phy; }
@@ -164,6 +169,7 @@ class NimBLEAdvertisedDevice {
     time_t          m_timestamp;
     bool            m_callbackSent;
     uint8_t         m_advLength;
+    uint8_t         m_channelIndex;
 #if CONFIG_BT_NIMBLE_EXT_ADV
     bool            m_isLegacyAdv;
     uint8_t         m_sid;

src/NimBLEScan.cpp

@@ -130,6 +130,7 @@ NimBLEScan::~NimBLEScan() {
 
             advertisedDevice->m_timestamp = time(nullptr);
             advertisedDevice->setRSSI(disc.rssi);
+            advertisedDevice->setChannelIndex(disc.channel_index);
             advertisedDevice->setPayload(disc.data, disc.length_data, (isLegacyAdv &&
                                          event_type == BLE_HCI_ADV_RPT_EVTYPE_SCAN_RSP));
 

src/nimble/nimble/host/include/host/ble_gap.h

@@ -403,6 +403,9 @@ struct ble_gap_ext_disc_desc {
      * set (BLE_ADDR_ANY otherwise).
      */
     ble_addr_t direct_addr;
+
+    /** Primary advertising channel index (0xFF if unavailable) */
+    uint8_t channel_index;
 };
 #endif
 
@@ -433,6 +436,9 @@ struct ble_gap_disc_desc {
      * event type (BLE_ADDR_ANY otherwise).
      */
     ble_addr_t direct_addr;
+
+    /** Primary advertising channel index (0xFF if unavailable) */
+    uint8_t channel_index;
 };
 
 struct ble_gap_repeat_pairing {

src/nimble/nimble/host/src/ble_hs_hci_evt.c

@@ -501,6 +501,7 @@ ble_hs_hci_evt_le_adv_rpt(uint8_t subevent, const void *data, unsigned int len)
     data += sizeof(*ev);
 
     desc.direct_addr = *BLE_ADDR_ANY;
+    desc.channel_index = 0xFF;
 
     for (i = 0; i < ev->num_reports; i++) {
         rpt = data;
@@ -513,6 +514,10 @@ ble_hs_hci_evt_le_adv_rpt(uint8_t subevent, const void *data, unsigned int len)
         desc.length_data = rpt->data_len;
         desc.data = rpt->data;
         desc.rssi = rpt->data[rpt->data_len];
+        /* Channel index follows RSSI if available */
+        if (data - (const uint8_t*)rpt > sizeof(rpt) + rpt->data_len + 1) {
+            desc.channel_index = rpt->data[rpt->data_len + 1];
+        }
 
         ble_gap_rx_adv_report(&desc);
     }
@@ -535,6 +540,7 @@ ble_hs_hci_evt_le_dir_adv_rpt(uint8_t subevent, const void *data, unsigned int l
     /* Data fields not present in a direct advertising report. */
     desc.data = NULL;
     desc.length_data = 0;
+    desc.channel_index = 0xFF;
 
     for (i = 0; i < ev->num_reports; i++) {
         desc.event_type = ev->reports[i].type;
@@ -612,6 +618,7 @@ ble_hs_hci_evt_le_ext_adv_rpt(uint8_t subevent, const void *data,
     report = &ev->reports[0];
     for (i = 0; i < ev->num_reports; i++) {
         memset(&desc, 0, sizeof(desc));
+        desc.channel_index = 0xFF;
 
         desc.props = (report->evt_type) & 0x1F;
         if (desc.props & BLE_HCI_ADV_LEGACY_MASK) {
@@ -649,6 +656,14 @@ ble_hs_hci_evt_le_ext_adv_rpt(uint8_t subevent, const void *data,
         desc.prim_phy = report->pri_phy;
         desc.sec_phy = report->sec_phy;
         desc.periodic_adv_itvl = report->periodic_itvl;
+        /* Channel index may follow the data if available */
+        if (report->data_len < 255) {
+            const uint8_t *channel_ptr = &report->data[report->data_len];
+            /* Verify we're not reading past the event data */
+            if ((const uint8_t*)channel_ptr < (const uint8_t*)data + len) {
+                desc.channel_index = *channel_ptr;
+            }
+        }
 
         ble_gap_rx_ext_adv_report(&desc);