[bluetooth_connection] Explicit pairing for rp2 (#18166)

esphome/components/ble_device_base/ble_gatt_client.h

@@ -95,6 +95,7 @@ class GattClientEventListener {
   virtual void on_notify_state(uint16_t handle, bool enabled, int error) = 0;
   /// Notification/indication data from the peer. data/len valid during the call.
   virtual void on_notify_data(uint16_t handle, const uint8_t *data, uint16_t len) = 0;
+  virtual void on_pairing_result(int status) {}
 };
 
 /// One GATT client connection slot. Operations return 0 when accepted
@@ -123,6 +124,8 @@ class BLEGattConnection {
   /// handle. Local registration only — the CCCD write is the API client's
   /// responsibility (it arrives as a plain write_descriptor).
   virtual int notify_characteristic(uint16_t handle, bool enable) = 0;
+  /// Initiate pairing on the live link. Completion: on_pairing_result().
+  virtual int pair() { return GATT_ERR_NOT_CONNECTED; }
   virtual int update_connection_params(uint16_t min_interval, uint16_t max_interval, uint16_t latency,
                                        uint16_t timeout) = 0;
 

esphome/components/bluetooth_connection/bluetooth_connection.h

@@ -48,20 +48,29 @@ static constexpr conn_err_t GATT_NOT_CONNECTED = ble_device_base::GATT_ERR_NOT_C
 
 // What the platform's connection backend supports beyond GATT operations;
 // the proxy derives its feature flags and legacy version from these.
-#ifdef USE_ESP32
+#if defined(USE_ESP32)
 static constexpr bool SUPPORTS_PAIRING = true;
 static constexpr bool SUPPORTS_CACHE_CLEARING = true;
+#elif defined(USE_RP2040_BLE) && defined(USE_BLE_GATT_CLIENT)
+// The rp2 BTstack backend pairs (just works + bonding); it has no service
+// cache to clear. Keyed on the backend, not the generic client define, so a
+// future backend without pairing keeps the stub arm below.
+static constexpr bool SUPPORTS_PAIRING = true;
+static constexpr bool SUPPORTS_CACHE_CLEARING = false;
 #else
 static constexpr bool SUPPORTS_PAIRING = false;
 static constexpr bool SUPPORTS_CACHE_CLEARING = false;
 #endif
 
 // Address-scoped (not connection-scoped) maintenance requests.
-#ifdef USE_ESP32
+#if defined(USE_ESP32) || (defined(USE_RP2040_BLE) && defined(USE_BLE_GATT_CLIENT))
 conn_err_t unpair_device(uint64_t address);
-conn_err_t clear_gatt_cache(uint64_t address);
 #else
 inline conn_err_t unpair_device(uint64_t) { return GATT_NOT_CONNECTED; }
+#endif
+#ifdef USE_ESP32
+conn_err_t clear_gatt_cache(uint64_t address);
+#else
 inline conn_err_t clear_gatt_cache(uint64_t) { return GATT_NOT_CONNECTED; }
 #endif
 

esphome/components/bluetooth_connection/bluetooth_connection_hub.cpp

@@ -74,6 +74,16 @@ void BluetoothConnection::check_disconnect_timeout_() {
   }
 }
 
+void BluetoothConnection::on_pairing_result(int status) {
+  if (this->address_ == 0) {
+    // A drop before completion already answered: reset_connection_slot_ sends
+    // the connection response, which the client's pair watcher raises on.
+    return;
+  }
+  this->paired_ = status == 0;
+  this->proxy_->send_device_pairing(this->address_, status == 0, status);
+}
+
 void BluetoothConnection::reset_connection_(conn_err_t reason) {
   if (this->pending_error_ != 0) {
     reason = this->pending_error_;
@@ -81,6 +91,7 @@ void BluetoothConnection::reset_connection_(conn_err_t reason) {
   }
   this->state_ = ClientState::IDLE;
   this->services_discovered_ = false;
+  this->paired_ = false;
   this->backend_->release_services();
   this->proxy_->reset_connection_slot_(this, reason);
 }

esphome/components/bluetooth_connection/bluetooth_connection_hub.h

@@ -49,6 +49,9 @@ class BluetoothConnection final : public ble_device_base::GattClientEventListene
     this->start_connect_();
   }
   void disconnect();
+  bool is_paired() const { return this->paired_; }
+  void set_unpaired() { this->paired_ = false; }
+  conn_err_t pair() { return this->backend_->pair(); }
   // A backend disconnect() is a single call that also cancels an in-progress
   // connect; there is no deferred-disconnect state to track.
   bool disconnect_pending() const { return false; }
@@ -87,6 +90,7 @@ class BluetoothConnection final : public ble_device_base::GattClientEventListene
   void on_write_result(uint16_t handle, int error) override;
   void on_notify_state(uint16_t handle, bool enabled, int error) override;
   void on_notify_data(uint16_t handle, const uint8_t *data, uint16_t len) override;
+  void on_pairing_result(int status) override;
 
  protected:
   friend class bluetooth_proxy::BluetoothProxy;
@@ -118,6 +122,7 @@ class BluetoothConnection final : public ble_device_base::GattClientEventListene
 
   // Group 5: 1-byte types
   ClientState state_{ClientState::IDLE};
+  bool paired_{false};
   ConnectionType connection_type_{ConnectionType::V1};
   uint8_t remote_addr_type_{0};
   uint8_t connection_index_{0};

esphome/components/bluetooth_connection/bluetooth_connection_rp2.cpp

@@ -1,4 +1,5 @@
 #include "bluetooth_connection_rp2.h"
+#include "bluetooth_connection.h"
 
 #if defined(USE_RP2040_BLE) && defined(USE_BLE_GATT_CLIENT)
 
@@ -51,6 +52,7 @@ using ble_device_base::MEDIUM_MIN_CONN_INTERVAL;
 RP2GattClient *RP2GattClient::instances[ESPHOME_BLE_GATT_CLIENT_COUNT] = {};
 uint8_t RP2GattClient::instance_count = 0;
 btstack_packet_callback_registration_t RP2GattClient::hci_event_registration = {};
+btstack_packet_callback_registration_t RP2GattClient::sm_event_registration = {};
 // NOLINTEND(cppcoreguidelines-avoid-non-const-global-variables)
 
 static ESPBTUUID uuid_from_btstack(uint16_t uuid16, const uint8_t uuid128[16]) {
@@ -88,6 +90,8 @@ void RP2GattClient::setup() {
     if (hci_event_registration.callback == nullptr) {
       hci_event_registration.callback = &RP2GattClient::hci_packet_handler;
       hci_add_event_handler(&hci_event_registration);
+      sm_event_registration.callback = &RP2GattClient::sm_packet_handler;
+      sm_add_event_handler(&sm_event_registration);
     }
   }
 
@@ -157,6 +161,38 @@ void RP2GattClient::hci_packet_handler(uint8_t type, uint16_t channel, uint8_t *
   }
 }
 
+void RP2GattClient::sm_packet_handler(uint8_t type, uint16_t channel, uint8_t *packet, uint16_t size) {
+  if (type != HCI_EVENT_PACKET) {
+    return;
+  }
+  switch (hci_event_packet_get_type(packet)) {
+    case SM_EVENT_JUST_WORKS_REQUEST:
+      // Confirming from the SM callback is the intended BTstack pattern.
+      // Unscoped on purpose: no peripheral role exists in-tree, and scoping
+      // would drop a request racing the queued CONNECTED event.
+      sm_just_works_confirm(sm_event_just_works_request_get_handle(packet));
+      break;
+    case SM_EVENT_PAIRING_COMPLETE: {
+      RP2GattClient *inst = instance_for_con_handle(sm_event_pairing_complete_get_handle(packet));
+      if (inst != nullptr) {
+        inst->enqueue_event_irq_(RP2GattEvent::PAIRING_RESULT, sm_event_pairing_complete_get_status(packet), 0);
+      }
+      break;
+    }
+    case SM_EVENT_REENCRYPTION_COMPLETE: {
+      // A bonded peer re-encrypts instead of pairing; BTstack emits only this
+      // event on that path, so it answers the PAIR request too.
+      RP2GattClient *inst = instance_for_con_handle(sm_event_reencryption_complete_get_handle(packet));
+      if (inst != nullptr) {
+        inst->enqueue_event_irq_(RP2GattEvent::PAIRING_RESULT, sm_event_reencryption_complete_get_status(packet), 0);
+      }
+      break;
+    }
+    default:
+      break;
+  }
+}
+
 void RP2GattClient::gatt_packet_handler(uint8_t type, uint16_t channel, uint8_t *packet, uint16_t size) {
   if (type != HCI_EVENT_PACKET) {
     return;
@@ -447,6 +483,11 @@ void RP2GattClient::handle_event_(const RP2GattEvent &event) {
     case RP2GattEvent::WRITE_NO_RSP_DONE:
       this->finish_write_no_rsp_(event.status);
       break;
+    case RP2GattEvent::PAIRING_RESULT:
+      if (this->listener_ != nullptr) {
+        this->listener_->on_pairing_result(event.status);
+      }
+      break;
   }
 }
 
@@ -1019,6 +1060,15 @@ int RP2GattClient::write_descriptor(uint16_t handle, const uint8_t *data, uint16
   return 0;
 }
 
+int RP2GattClient::pair() {
+  if (this->state_ != EngineState::READY) {
+    return GATT_ERR_NOT_CONNECTED;
+  }
+  BluetoothLock lock;
+  sm_request_pairing(this->con_handle_);  // void API; completion via SM events
+  return 0;
+}
+
 int RP2GattClient::notify_characteristic(uint16_t handle, bool enable) {
   if (this->state_ != EngineState::READY) {
     return GATT_ERR_NOT_CONNECTED;
@@ -1064,6 +1114,30 @@ int RP2GattClient::update_connection_params(uint16_t min_interval, uint16_t max_
   return gap_update_connection_parameters(this->con_handle_, min_interval, max_interval, latency, timeout);
 }
 
+conn_err_t unpair_device(uint64_t address) {
+  uint8_t mac[6];
+  ble_device_base::uint64_to_mac_msb_first(address, mac);
+  bool found = false;
+  BluetoothLock lock;
+  // Exhaustive: the db keys on (type, address), so stale entries can share
+  // the same address bytes under different types.
+  for (int i = 0; i < le_device_db_max_count(); i++) {
+    int addr_type = 0;
+    bd_addr_t addr;
+    le_device_db_info(i, &addr_type, addr, nullptr);
+    if (addr_type != BD_ADDR_TYPE_UNKNOWN && memcmp(addr, mac, sizeof(bd_addr_t)) == 0) {
+      le_device_db_remove(i);
+      found = true;
+    }
+  }
+  if (found) {
+    return CONN_OK;
+  }
+  // No bond for this address; the shared error domain has no closer code
+  // (esp32 parity: its remove-bond call also errors for an unknown address).
+  return GATT_NOT_CONNECTED;
+}
+
 }  // namespace esphome::bluetooth_connection
 
 #endif  // USE_RP2040_BLE && USE_BLE_GATT_CLIENT

esphome/components/bluetooth_connection/bluetooth_connection_rp2.h

@@ -51,6 +51,7 @@ struct RP2GattEvent {
     MTU_EXCHANGED,      // value = negotiated MTU
     QUERY_COMPLETE,     // status = ATT status of the finished query
     WRITE_NO_RSP_DONE,  // status = result of the deferred write
+    PAIRING_RESULT,     // status = SM pairing status (0 = bonded)
   };
   Type type;
   uint8_t status;
@@ -89,6 +90,7 @@ class RP2GattClient final : public Component,
   int read_descriptor(uint16_t handle) override;
   int write_descriptor(uint16_t handle, const uint8_t *data, uint16_t len) override;
   int notify_characteristic(uint16_t handle, bool enable) override;
+  int pair() override;
   int update_connection_params(uint16_t min_interval, uint16_t max_interval, uint16_t latency,
                                uint16_t timeout) override;
   ble_device_base::GattServiceTable get_service_table() override;
@@ -120,6 +122,7 @@ class RP2GattClient final : public Component,
   // BTstack packet handlers (IRQ context: copy-and-enqueue only).
   static void hci_packet_handler(uint8_t type, uint16_t channel, uint8_t *packet, uint16_t size);
   static void gatt_packet_handler(uint8_t type, uint16_t channel, uint8_t *packet, uint16_t size);
+  static void sm_packet_handler(uint8_t type, uint16_t channel, uint8_t *packet, uint16_t size);
   static RP2GattClient *instance_for_con_handle(hci_con_handle_t con_handle);
 
   void handle_gatt_event_irq_(uint8_t event_type, const uint8_t *packet);
@@ -205,6 +208,8 @@ class RP2GattClient final : public Component,
   static uint8_t instance_count;
   // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
   static btstack_packet_callback_registration_t hci_event_registration;
+  // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+  static btstack_packet_callback_registration_t sm_event_registration;
 };
 
 }  // namespace esphome::bluetooth_connection

esphome/components/bluetooth_proxy/bluetooth_proxy.cpp

@@ -311,12 +311,13 @@ void BluetoothProxy::bluetooth_device_request(const api::BluetoothDeviceRequest
       break;
     }
     case api::enums::BLUETOOTH_DEVICE_REQUEST_TYPE_PAIR: {
-#ifdef USE_ESP32
+      // Both connection classes expose the same pairing surface; success is
+      // reported when the platform's pairing completion arrives.
       auto *connection = this->get_connection_(msg.address, false);
       if (connection != nullptr) {
         if (!connection->is_paired()) {
           auto err = connection->pair();
-          if (err != ESP_OK) {
+          if (err != CONN_OK) {
             this->send_device_pairing(msg.address, false, err);
           }
         } else {
@@ -326,15 +327,18 @@ void BluetoothProxy::bluetooth_device_request(const api::BluetoothDeviceRequest
         // Answer instead of leaving the client to time out.
         this->send_device_pairing(msg.address, false, GATT_NOT_CONNECTED);
       }
-#else
-      // Explicit pairing is not offered (FEATURE_PAIRING is not advertised);
-      // peripheral-initiated security still works through the platform's SM.
-      this->send_device_pairing(msg.address, false, GATT_NOT_CONNECTED);
-#endif
       break;
     }
     case api::enums::BLUETOOTH_DEVICE_REQUEST_TYPE_UNPAIR: {
       conn_err_t ret = bluetooth_connection::unpair_device(msg.address);
+      if (ret == CONN_OK) {
+        // The bond is gone; a live connection must not short-circuit the
+        // next PAIR as already paired.
+        auto *connection = this->get_connection_(msg.address, false);
+        if (connection != nullptr) {
+          connection->set_unpaired();
+        }
+      }
       this->send_device_unpairing(msg.address, ret == CONN_OK, ret);
       break;
     }

esphome/components/esp32_ble_client/ble_client_base.h

@@ -92,6 +92,8 @@ class BLEClientBase : public espbt::ESPBTClient, public Component {
   uint16_t get_conn_id() const { return this->conn_id_; }
   uint64_t get_address() const { return this->address_; }
   bool is_paired() const { return this->paired_; }
+  // The proxy clears this when a bond is removed while the link is up.
+  void set_unpaired() { this->paired_ = false; }
 
   uint8_t get_connection_index() const { return this->connection_index_; }
 

tests/components/ble_device_base/test_gatt_client_contract.cpp

@@ -46,6 +46,16 @@ class MinimalConnection : public BLEGattConnection {
   void release_services() override {}
 };
 
+TEST(BleGattClientContract, PairingDefaultsAreSafeForNonPairingBackends) {
+  // pair() defaults to not-connected and on_pairing_result() to a no-op, so
+  // a backend without pairing still answers the client through the dispatch.
+  MinimalConnection conn;
+  RecordingListener listener;
+  conn.set_listener(&listener);
+  EXPECT_EQ(conn.pair(), GATT_ERR_NOT_CONNECTED);
+  listener.on_pairing_result(0);  // must not crash: default body
+}
+
 TEST(BleGattClientContract, MinimalImplementerCompilesAndRoutesEvents) {
   MinimalConnection connection;
   RecordingListener listener;

tests/components/bluetooth_connection/__init__.py

@@ -0,0 +1,18 @@
+import esphome.codegen as cg
+from tests.testing_helpers import ComponentManifestOverride
+
+
+def override_manifest(manifest: ComponentManifestOverride) -> None:
+    # close_service_batch compiles only under BLUETOOTH_CONNECTION_HAS_GATT;
+    # emit the backend define so the host build exercises it.
+    async def to_code_testing(config):
+        # These defines are global to the merged host test binary; safe
+        # because no co-compiled test observes them.
+        cg.add_define("USE_BLE_GATT_CLIENT")
+        cg.add_define("USE_BLUETOOTH_PROXY")
+        cg.add_define("BLUETOOTH_PROXY_ADVERTISEMENT_BATCH_SIZE", 16)
+        cg.add_define("BLUETOOTH_PROXY_MAX_CONNECTIONS", 1)
+
+    manifest.to_code = to_code_testing
+    # The batcher sizes api protobuf messages.
+    manifest.dependencies = manifest.dependencies + ["api"]

tests/components/bluetooth_connection/test_close_service_batch.cpp

@@ -0,0 +1,58 @@
+#include "esphome/components/bluetooth_connection/bluetooth_connection.h"
+
+#include <gtest/gtest.h>
+
+#include "esphome/components/api/api_pb2.h"
+
+namespace esphome::bluetooth_connection {
+
+// The three cursor behaviors: a fitting service advances and continues, an
+// overflowing batch with >1 service pops and retries it, and a single
+// oversized service is force-advanced so the stream cannot wedge.
+
+static void add_service(api::BluetoothGATTGetServicesResponse &resp, uint16_t characteristics) {
+  resp.services.emplace_back();
+  auto &svc = resp.services.back();
+  svc.handle = resp.services.size();
+  svc.uuid = {0x1234567890ABCDEFULL, 0xFEDCBA0987654321ULL};
+  svc.characteristics.init(characteristics);
+  for (uint16_t i = 0; i < characteristics; i++) {
+    auto &chr = svc.characteristics.emplace_back();
+    chr.handle = 100 + i;
+    chr.properties = 0x12;
+    chr.uuid = {0x1234567890ABCDEFULL, 0xFEDCBA0987654321ULL};
+  }
+}
+
+TEST(CloseServiceBatch, FittingServiceAdvancesAndContinues) {
+  api::BluetoothGATTGetServicesResponse resp;
+  add_service(resp, 1);
+  size_t current_size = 0;
+  int16_t cursor = 0;
+  EXPECT_EQ(close_service_batch(resp, current_size, cursor, 0, "AA:BB"), BatchClose::CONTINUE);
+  EXPECT_EQ(cursor, 1);
+  EXPECT_GT(current_size, 0u);
+}
+
+TEST(CloseServiceBatch, OverflowPopsAndRetriesWithoutAdvancing) {
+  api::BluetoothGATTGetServicesResponse resp;
+  add_service(resp, 1);
+  add_service(resp, 1);
+  size_t current_size = MAX_PACKET_SIZE - 10;  // any service is bigger than 10 bytes
+  int16_t cursor = 5;
+  EXPECT_EQ(close_service_batch(resp, current_size, cursor, 0, "AA:BB"), BatchClose::SEND);
+  EXPECT_EQ(resp.services.size(), 1u);  // popped for the next batch
+  EXPECT_EQ(cursor, 5);                 // not advanced: retried next batch
+}
+
+TEST(CloseServiceBatch, SingleOversizedServiceForceAdvances) {
+  api::BluetoothGATTGetServicesResponse resp;
+  add_service(resp, 60);  // ~30 bytes per characteristic, far past the budget
+  ASSERT_GT(resp.services.back().calculate_size(), MAX_PACKET_SIZE);
+  size_t current_size = 0;
+  int16_t cursor = 7;
+  EXPECT_EQ(close_service_batch(resp, current_size, cursor, 0, "AA:BB"), BatchClose::SEND);
+  EXPECT_EQ(cursor, 8);  // advanced despite not fitting, so the stream moves on
+}
+
+}  // namespace esphome::bluetooth_connection