refactor: change api and support varying scan buffer sizes

* Add Scanner type which wraps the central to provide scan features
* Make scanner buffer configurable size in order to handle large number
  of reports.
* Only add valid advertising reports to scan buffer.

examples/serial-hci/Cargo.toml

@@ -7,7 +7,7 @@ edition = "2021"
 env_logger = "0.10.0"
 log = "0.4"
 embedded-io-adapters = { version = "0.6.1", features = ["tokio-1"] }
-embassy-sync = { version = "0.6.0", features = ["log"] }
+embassy-sync = { version = "0.6", features = ["log"] }
 embassy-time = { version = "0.4", features = ["log", "std", "generic-queue-8"] }
 critical-section = { version = "1.1", features = ["std"] }
 tokio = { version = "1", features = ["full"] }

host/src/advertise.rs

@@ -475,6 +475,9 @@ pub struct AdStructureIter<'d> {
 impl<'d> AdStructureIter<'d> {
     fn read(&mut self) -> Result<AdStructure<'d>, codec::Error> {
         let len: u8 = self.cursor.read()?;
+        if len < 2 {
+            return Err(codec::Error::InvalidValue);
+        }
         let code: u8 = self.cursor.read()?;
         let data = self.cursor.slice(len as usize - 1)?;
         match code {

host/src/central.rs

@@ -1,25 +1,17 @@
 //! Functionality for the BLE central role.
-#[cfg(feature = "scan")]
-use bt_hci::cmd::le::LeSetScanParams;
-use bt_hci::cmd::le::{
-    LeAddDeviceToFilterAcceptList, LeClearFilterAcceptList, LeCreateConn, LeExtCreateConn, LeSetExtScanEnable,
-    LeSetExtScanParams, LeSetScanEnable,
-};
+use crate::connection::{ConnectConfig, Connection};
+use crate::scan::PhySet;
+use crate::{BleHostError, Error, Stack};
+use bt_hci::cmd::le::{LeAddDeviceToFilterAcceptList, LeClearFilterAcceptList, LeCreateConn, LeExtCreateConn};
 use bt_hci::controller::{Controller, ControllerCmdAsync, ControllerCmdSync};
-use bt_hci::param::{AddrKind, BdAddr, FilterDuplicates, InitiatingPhy, LeConnRole, PhyParams, ScanningPhy};
+use bt_hci::param::{AddrKind, BdAddr, InitiatingPhy, LeConnRole, PhyParams};
 #[cfg(feature = "controller-host-flow-control")]
 use bt_hci::param::{ConnHandleCompletedPackets, ControllerToHostFlowControl};
 use embassy_futures::select::{select, Either};
 
-use crate::connection::{ConnectConfig, Connection};
-#[cfg(feature = "scan")]
-use crate::scan::ScanReport;
-use crate::scan::{PhySet, ScanConfig};
-use crate::{BleHostError, Error, Stack};
-
 /// A type implementing the BLE central role.
 pub struct Central<'d, C: Controller> {
-    stack: Stack<'d, C>,
+    pub(crate) stack: Stack<'d, C>,
 }
 
 impl<'d, C: Controller> Central<'d, C> {
@@ -82,9 +74,7 @@ impl<'d, C: Controller> Central<'d, C> {
     where
         C: ControllerCmdSync<LeClearFilterAcceptList>
             + ControllerCmdSync<LeAddDeviceToFilterAcceptList>
-            + ControllerCmdAsync<LeExtCreateConn>
-            + ControllerCmdSync<LeSetExtScanEnable>
-            + ControllerCmdSync<LeSetExtScanParams>,
+            + ControllerCmdAsync<LeExtCreateConn>,
     {
         if config.scan_config.filter_accept_list.is_empty() {
             return Err(Error::InvalidValue.into());
@@ -109,7 +99,7 @@ impl<'d, C: Controller> Central<'d, C> {
             min_ce_len: config.connect_params.event_length.into(),
             max_ce_len: config.connect_params.event_length.into(),
         };
-        let phy_params = Self::create_phy_params(initiating, config.scan_config.phys);
+        let phy_params = create_phy_params(initiating, config.scan_config.phys);
 
         host.async_command(LeExtCreateConn::new(
             true,
@@ -136,24 +126,6 @@ impl<'d, C: Controller> Central<'d, C> {
         }
     }
 
-    fn create_phy_params<P: Copy>(phy: P, phys: PhySet) -> PhyParams<P> {
-        let phy_params: PhyParams<P> = PhyParams {
-            le_1m_phy: match phys {
-                PhySet::M1 | PhySet::M1M2 | PhySet::M1Coded | PhySet::M1M2Coded => Some(phy),
-                _ => None,
-            },
-            le_2m_phy: match phys {
-                PhySet::M2 | PhySet::M1M2 | PhySet::M2Coded | PhySet::M1M2Coded => Some(phy),
-                _ => None,
-            },
-            le_coded_phy: match phys {
-                PhySet::M2Coded | PhySet::Coded | PhySet::M1Coded | PhySet::M1M2Coded => Some(phy),
-                _ => None,
-            },
-        };
-        phy_params
-    }
-
     pub(crate) async fn set_accept_filter(
         &mut self,
         filter_accept_list: &[(AddrKind, &BdAddr)],
@@ -169,135 +141,22 @@ impl<'d, C: Controller> Central<'d, C> {
         }
         Ok(())
     }
+}
 
-    #[cfg(feature = "scan")]
-    async fn start_scan(&mut self, config: &ScanConfig<'_>) -> Result<(), BleHostError<C::Error>>
-    where
-        C: ControllerCmdSync<LeSetScanParams>
-            + ControllerCmdSync<LeSetScanEnable>
-            + ControllerCmdSync<LeClearFilterAcceptList>
-            + ControllerCmdSync<LeAddDeviceToFilterAcceptList>,
-    {
-        let host = self.stack.host;
-        self.set_accept_filter(config.filter_accept_list).await?;
-
-        let params = LeSetScanParams::new(
-            if config.active {
-                bt_hci::param::LeScanKind::Active
-            } else {
-                bt_hci::param::LeScanKind::Passive
-            },
-            config.interval.into(),
-            config.interval.into(),
-            bt_hci::param::AddrKind::PUBLIC,
-            if config.filter_accept_list.is_empty() {
-                bt_hci::param::ScanningFilterPolicy::BasicUnfiltered
-            } else {
-                bt_hci::param::ScanningFilterPolicy::BasicFiltered
-            },
-        );
-        host.command(params).await?;
-        host.command(LeSetScanEnable::new(true, true)).await?;
-        Ok(())
-    }
-
-    async fn start_scan_ext(&mut self, config: &ScanConfig<'_>) -> Result<(), BleHostError<C::Error>>
-    where
-        C: ControllerCmdSync<LeSetExtScanEnable>
-            + ControllerCmdSync<LeSetExtScanParams>
-            + ControllerCmdSync<LeClearFilterAcceptList>
-            + ControllerCmdSync<LeAddDeviceToFilterAcceptList>,
-    {
-        self.set_accept_filter(config.filter_accept_list).await?;
-
-        let scanning = ScanningPhy {
-            active_scan: config.active,
-            scan_interval: config.interval.into(),
-            scan_window: config.window.into(),
-        };
-        let phy_params = Self::create_phy_params(scanning, config.phys);
-        let host = self.stack.host;
-        host.command(LeSetExtScanParams::new(
-            host.address.map(|s| s.kind).unwrap_or(AddrKind::PUBLIC),
-            if config.filter_accept_list.is_empty() {
-                bt_hci::param::ScanningFilterPolicy::BasicUnfiltered
-            } else {
-                bt_hci::param::ScanningFilterPolicy::BasicFiltered
-            },
-            phy_params,
-        ))
-        .await?;
-        host.command(LeSetExtScanEnable::new(
-            true,
-            FilterDuplicates::Disabled,
-            config.timeout.into(),
-            bt_hci::param::Duration::from_secs(0),
-        ))
-        .await?;
-        Ok(())
-    }
-
-    async fn stop_scan(&mut self) -> Result<(), BleHostError<C::Error>>
-    where
-        C: ControllerCmdSync<LeSetScanEnable>,
-    {
-        let host = self.stack.host;
-        host.command(LeSetScanEnable::new(false, false)).await?;
-        Ok(())
-    }
-
-    async fn stop_scan_ext(&mut self) -> Result<(), BleHostError<C::Error>>
-    where
-        C: ControllerCmdSync<LeSetExtScanEnable>,
-    {
-        let host = self.stack.host;
-        host.command(LeSetExtScanEnable::new(
-            false,
-            FilterDuplicates::Disabled,
-            bt_hci::param::Duration::from_secs(0),
-            bt_hci::param::Duration::from_secs(0),
-        ))
-        .await?;
-        Ok(())
-    }
-
-    /// Performs an extended BLE scan, return a report for discovering peripherals.
-    ///
-    /// Scan is stopped when a report is received. Call this method repeatedly to continue scanning.
-    #[cfg(feature = "scan")]
-    pub async fn scan_ext(&mut self, config: &ScanConfig<'_>) -> Result<ScanReport, BleHostError<C::Error>>
-    where
-        C: ControllerCmdSync<LeSetExtScanEnable>
-            + ControllerCmdSync<LeSetExtScanParams>
-            + ControllerCmdSync<LeClearFilterAcceptList>
-            + ControllerCmdSync<LeAddDeviceToFilterAcceptList>,
-    {
-        let host = self.stack.host;
-        self.start_scan_ext(config).await?;
-        let Some(report) = host.scanner.receive().await else {
-            return Err(Error::Timeout.into());
-        };
-        self.stop_scan_ext().await?;
-        Ok(report)
-    }
-
-    /// Performs a BLE scan, return a report for discovering peripherals.
-    ///
-    /// Scan is stopped when a report is received. Call this method repeatedly to continue scanning.
-    #[cfg(feature = "scan")]
-    pub async fn scan(&mut self, config: &ScanConfig<'_>) -> Result<ScanReport, BleHostError<C::Error>>
-    where
-        C: ControllerCmdSync<LeSetScanParams>
-            + ControllerCmdSync<LeSetScanEnable>
-            + ControllerCmdSync<LeClearFilterAcceptList>
-            + ControllerCmdSync<LeAddDeviceToFilterAcceptList>,
-    {
-        let host = self.stack.host;
-        self.start_scan(config).await?;
-        let Some(report) = host.scanner.receive().await else {
-            return Err(Error::Timeout.into());
-        };
-        self.stop_scan().await?;
-        Ok(report)
-    }
+pub(crate) fn create_phy_params<P: Copy>(phy: P, phys: PhySet) -> PhyParams<P> {
+    let phy_params: PhyParams<P> = PhyParams {
+        le_1m_phy: match phys {
+            PhySet::M1 | PhySet::M1M2 | PhySet::M1Coded | PhySet::M1M2Coded => Some(phy),
+            _ => None,
+        },
+        le_2m_phy: match phys {
+            PhySet::M2 | PhySet::M1M2 | PhySet::M2Coded | PhySet::M1M2Coded => Some(phy),
+            _ => None,
+        },
+        le_coded_phy: match phys {
+            PhySet::M2Coded | PhySet::Coded | PhySet::M1Coded | PhySet::M1M2Coded => Some(phy),
+            _ => None,
+        },
+    };
+    phy_params
 }