Merge pull request #88 from embassy-rs/lookup-complete-handle

fix an issue where the returned handle would not contain the cccd handle
embassy-rs · Aug 22, 2024 · c4ac325 · c4ac325
2 parents bb5002c + cbafa08
commit c4ac325
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Showing 3 changed files with 33 additions and 13 deletions.
diff --git a/host/src/attribute.rs b/host/src/attribute.rs
@@ -364,6 +364,34 @@ impl<'d, M: RawMutex, const MAX: usize> AttributeTable<'d, M, MAX> {
             Err(Error::NotFound)
         })
     }
+
+    pub(crate) fn find_characteristic_by_value_handle(&self, handle: u16) -> Result<Characteristic, Error> {
+        self.iterate(|mut it| {
+            while let Some(att) = it.next() {
+                if att.handle == handle {
+                    // If next is CCCD
+                    if let Some(next) = it.next() {
+                        if let AttributeData::Cccd {
+                            notifications: _,
+                            indications: _,
+                        } = &next.data
+                        {
+                            return Ok(Characteristic {
+                                handle,
+                                cccd_handle: Some(next.handle),
+                            });
+                        }
+                    } else {
+                        return Ok(Characteristic {
+                            handle,
+                            cccd_handle: None,
+                        });
+                    }
+                }
+            }
+            Err(Error::NotFound)
+        })
+    }
 }
 
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]

diff --git a/host/src/gatt.rs b/host/src/gatt.rs
@@ -58,26 +58,17 @@ impl<'reference, 'values, M: RawMutex, const MAX: usize, const MTU: usize>
                                 let event = match att {
                                     AttReq::Write { handle, data } => Some(GattEvent::Write {
                                         connection,
-                                        handle: Characteristic {
-                                            handle,
-                                            cccd_handle: None,
-                                        },
+                                        handle: self.server.table.find_characteristic_by_value_handle(handle)?,
                                     }),
 
                                     AttReq::Read { handle } => Some(GattEvent::Read {
                                         connection,
-                                        handle: Characteristic {
-                                            handle,
-                                            cccd_handle: None,
-                                        },
+                                        handle: self.server.table.find_characteristic_by_value_handle(handle)?,
                                     }),
 
                                     AttReq::ReadBlob { handle, offset } => Some(GattEvent::Read {
                                         connection,
-                                        handle: Characteristic {
-                                            handle,
-                                            cccd_handle: None,
-                                        },
+                                        handle: self.server.table.find_characteristic_by_value_handle(handle)?,
                                     }),
                                     _ => None,
                                 };

diff --git a/host/tests/gatt.rs b/host/tests/gatt.rs
@@ -57,7 +57,7 @@ async fn gatt_client_server() {
         table.add_service(Service::new(0x1801));
 
         // Custom service
-        table.add_service(Service::new(SERVICE_UUID.clone()))
+        let value_handle = table.add_service(Service::new(SERVICE_UUID.clone()))
         .add_characteristic(
             VALUE_UUID.clone(),
             &[CharacteristicProp::Read, CharacteristicProp::Write, CharacteristicProp::Notify],
@@ -79,6 +79,7 @@ async fn gatt_client_server() {
                             connection: _,
                             handle,
                         }) => {
+                            assert_eq!(handle, value_handle);
                             let _ = table.get(handle, |value| {
                                 assert_eq!(expected, value[0]);
                                 expected += 1;