Bluetooth Proxy active connections (#3817)

esphome/components/esp32_ble_client/__init__.py

@@ -0,0 +1,12 @@
+import esphome.codegen as cg
+
+from esphome.components import esp32_ble_tracker
+
+AUTO_LOAD = ["esp32_ble_tracker"]
+CODEOWNERS = ["@jesserockz"]
+DEPENDENCIES = ["esp32"]
+
+esp32_ble_client_ns = cg.esphome_ns.namespace("esp32_ble_client")
+BLEClientBase = esp32_ble_client_ns.class_(
+    "BLEClientBase", esp32_ble_tracker.ESPBTClient, cg.Component
+)

esphome/components/esp32_ble_client/ble_characteristic.cpp

@@ -0,0 +1,83 @@
+#include "ble_characteristic.h"
+#include "ble_client_base.h"
+#include "ble_service.h"
+
+#include "esphome/core/log.h"
+
+#ifdef USE_ESP32
+
+namespace esphome {
+namespace esp32_ble_client {
+
+static const char *const TAG = "esp32_ble_client.characteristic";
+
+BLECharacteristic::~BLECharacteristic() {
+  for (auto &desc : this->descriptors)
+    delete desc;  // NOLINT(cppcoreguidelines-owning-memory)
+}
+
+void BLECharacteristic::parse_descriptors() {
+  uint16_t offset = 0;
+  esp_gattc_descr_elem_t result;
+
+  while (true) {
+    uint16_t count = 1;
+    esp_gatt_status_t status =
+        esp_ble_gattc_get_all_descr(this->service->client->get_gattc_if(), this->service->client->get_conn_id(),
+                                    this->handle, &result, &count, offset);
+    if (status == ESP_GATT_INVALID_OFFSET || status == ESP_GATT_NOT_FOUND) {
+      break;
+    }
+    if (status != ESP_GATT_OK) {
+      ESP_LOGW(TAG, "esp_ble_gattc_get_all_descr error, status=%d", status);
+      break;
+    }
+    if (count == 0) {
+      break;
+    }
+
+    BLEDescriptor *desc = new BLEDescriptor();  // NOLINT(cppcoreguidelines-owning-memory)
+    desc->uuid = espbt::ESPBTUUID::from_uuid(result.uuid);
+    desc->handle = result.handle;
+    desc->characteristic = this;
+    this->descriptors.push_back(desc);
+    ESP_LOGV(TAG, "   descriptor %s, handle 0x%x", desc->uuid.to_string().c_str(), desc->handle);
+    offset++;
+  }
+}
+
+BLEDescriptor *BLECharacteristic::get_descriptor(espbt::ESPBTUUID uuid) {
+  for (auto &desc : this->descriptors) {
+    if (desc->uuid == uuid)
+      return desc;
+  }
+  return nullptr;
+}
+BLEDescriptor *BLECharacteristic::get_descriptor(uint16_t uuid) {
+  return this->get_descriptor(espbt::ESPBTUUID::from_uint16(uuid));
+}
+BLEDescriptor *BLECharacteristic::get_descriptor_by_handle(uint16_t handle) {
+  for (auto &desc : this->descriptors) {
+    if (desc->handle == handle)
+      return desc;
+  }
+  return nullptr;
+}
+
+void BLECharacteristic::write_value(uint8_t *new_val, int16_t new_val_size, esp_gatt_write_type_t write_type) {
+  auto *client = this->service->client;
+  auto status = esp_ble_gattc_write_char(client->get_gattc_if(), client->get_conn_id(), this->handle, new_val_size,
+                                         new_val, write_type, ESP_GATT_AUTH_REQ_NONE);
+  if (status) {
+    ESP_LOGW(TAG, "Error sending write value to BLE gattc server, status=%d", status);
+  }
+}
+
+void BLECharacteristic::write_value(uint8_t *new_val, int16_t new_val_size) {
+  write_value(new_val, new_val_size, ESP_GATT_WRITE_TYPE_NO_RSP);
+}
+
+}  // namespace esp32_ble_client
+}  // namespace esphome
+
+#endif  // USE_ESP32

esphome/components/esp32_ble_client/ble_characteristic.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#ifdef USE_ESP32
+
+#include "esphome/components/esp32_ble_tracker/esp32_ble_tracker.h"
+
+#include "ble_descriptor.h"
+
+namespace esphome {
+namespace esp32_ble_client {
+
+namespace espbt = esphome::esp32_ble_tracker;
+
+class BLEService;
+
+class BLECharacteristic {
+ public:
+  ~BLECharacteristic();
+  espbt::ESPBTUUID uuid;
+  uint16_t handle;
+  esp_gatt_char_prop_t properties;
+  std::vector<BLEDescriptor *> descriptors;
+  void parse_descriptors();
+  BLEDescriptor *get_descriptor(espbt::ESPBTUUID uuid);
+  BLEDescriptor *get_descriptor(uint16_t uuid);
+  BLEDescriptor *get_descriptor_by_handle(uint16_t handle);
+  void write_value(uint8_t *new_val, int16_t new_val_size);
+  void write_value(uint8_t *new_val, int16_t new_val_size, esp_gatt_write_type_t write_type);
+  BLEService *service;
+};
+
+}  // namespace esp32_ble_client
+}  // namespace esphome
+
+#endif  // USE_ESP32

esphome/components/esp32_ble_client/ble_client_base.cpp

@@ -0,0 +1,324 @@
+#include "ble_client_base.h"
+
+#include "esphome/core/helpers.h"
+#include "esphome/core/log.h"
+
+#ifdef USE_ESP32
+
+namespace esphome {
+namespace esp32_ble_client {
+
+static const char *const TAG = "esp32_ble_client";
+
+void BLEClientBase::setup() {
+  auto ret = esp_ble_gattc_app_register(this->app_id);
+  if (ret) {
+    ESP_LOGE(TAG, "gattc app register failed. app_id=%d code=%d", this->app_id, ret);
+    this->mark_failed();
+  }
+  this->set_state(espbt::ClientState::IDLE);
+}
+
+void BLEClientBase::loop() {
+  if (this->state_ == espbt::ClientState::DISCOVERED) {
+    this->connect();
+  }
+}
+
+float BLEClientBase::get_setup_priority() const { return setup_priority::AFTER_BLUETOOTH; }
+
+bool BLEClientBase::parse_device(const espbt::ESPBTDevice &device) {
+  if (device.address_uint64() != this->address_)
+    return false;
+  if (this->state_ != espbt::ClientState::IDLE)
+    return false;
+
+  ESP_LOGD(TAG, "Found device at MAC address [%s]", device.address_str().c_str());
+  this->set_state(espbt::ClientState::DISCOVERED);
+
+  auto addr = device.address_uint64();
+  this->remote_bda_[0] = (addr >> 40) & 0xFF;
+  this->remote_bda_[1] = (addr >> 32) & 0xFF;
+  this->remote_bda_[2] = (addr >> 24) & 0xFF;
+  this->remote_bda_[3] = (addr >> 16) & 0xFF;
+  this->remote_bda_[4] = (addr >> 8) & 0xFF;
+  this->remote_bda_[5] = (addr >> 0) & 0xFF;
+  this->remote_addr_type_ = device.get_address_type();
+  return true;
+}
+
+std::string BLEClientBase::address_str() const {
+  return str_snprintf("%02x:%02x:%02x:%02x:%02x:%02x", 17, (uint8_t)(this->address_ >> 40) & 0xff,
+                      (uint8_t)(this->address_ >> 32) & 0xff, (uint8_t)(this->address_ >> 24) & 0xff,
+                      (uint8_t)(this->address_ >> 16) & 0xff, (uint8_t)(this->address_ >> 8) & 0xff,
+                      (uint8_t)(this->address_ >> 0) & 0xff);
+}
+
+void BLEClientBase::connect() {
+  ESP_LOGI(TAG, "Attempting BLE connection to %s", this->address_str().c_str());
+  auto ret = esp_ble_gattc_open(this->gattc_if_, this->remote_bda_, this->remote_addr_type_, true);
+  if (ret) {
+    ESP_LOGW(TAG, "esp_ble_gattc_open error, address=%s status=%d", this->address_str().c_str(), ret);
+    this->set_state(espbt::ClientState::IDLE);
+  } else {
+    this->set_state(espbt::ClientState::CONNECTING);
+  }
+}
+
+void BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t esp_gattc_if,
+                                        esp_ble_gattc_cb_param_t *param) {
+  if (event == ESP_GATTC_REG_EVT && this->app_id != param->reg.app_id)
+    return;
+  if (event != ESP_GATTC_REG_EVT && esp_gattc_if != ESP_GATT_IF_NONE && esp_gattc_if != this->gattc_if_)
+    return;
+
+  switch (event) {
+    case ESP_GATTC_REG_EVT: {
+      if (param->reg.status == ESP_GATT_OK) {
+        ESP_LOGV(TAG, "gattc registered app id %d", this->app_id);
+        this->gattc_if_ = esp_gattc_if;
+      } else {
+        ESP_LOGE(TAG, "gattc app registration failed id=%d code=%d", param->reg.app_id, param->reg.status);
+      }
+      break;
+    }
+    case ESP_GATTC_OPEN_EVT: {
+      ESP_LOGV(TAG, "[%s] ESP_GATTC_OPEN_EVT", this->address_str().c_str());
+      this->conn_id_ = param->open.conn_id;
+      if (param->open.status != ESP_GATT_OK && param->open.status != ESP_GATT_ALREADY_OPEN) {
+        ESP_LOGW(TAG, "connect to %s failed, status=%d", this->address_str().c_str(), param->open.status);
+        this->set_state(espbt::ClientState::IDLE);
+        break;
+      }
+      break;
+    }
+    case ESP_GATTC_CONNECT_EVT: {
+      ESP_LOGV(TAG, "[%s] ESP_GATTC_CONNECT_EVT", this->address_str().c_str());
+      if (this->conn_id_ != param->connect.conn_id) {
+        ESP_LOGD(TAG, "[%s] Unexpected conn_id in CONNECT_EVT: param conn=%d, open conn=%d",
+                 this->address_str().c_str(), param->connect.conn_id, this->conn_id_);
+      }
+      auto ret = esp_ble_gattc_send_mtu_req(this->gattc_if_, param->connect.conn_id);
+      if (ret) {
+        ESP_LOGW(TAG, "esp_ble_gattc_send_mtu_req failed, status=%x", ret);
+      }
+      break;
+    }
+    case ESP_GATTC_CFG_MTU_EVT: {
+      if (param->cfg_mtu.status != ESP_GATT_OK) {
+        ESP_LOGW(TAG, "cfg_mtu to %s failed, mtu %d, status %d", this->address_str().c_str(), param->cfg_mtu.mtu,
+                 param->cfg_mtu.status);
+        this->set_state(espbt::ClientState::IDLE);
+        break;
+      }
+      ESP_LOGV(TAG, "cfg_mtu status %d, mtu %d", param->cfg_mtu.status, param->cfg_mtu.mtu);
+      this->mtu_ = param->cfg_mtu.mtu;
+      esp_ble_gattc_search_service(esp_gattc_if, param->cfg_mtu.conn_id, nullptr);
+      break;
+    }
+    case ESP_GATTC_DISCONNECT_EVT: {
+      if (memcmp(param->disconnect.remote_bda, this->remote_bda_, 6) != 0) {
+        return;
+      }
+      ESP_LOGV(TAG, "[%s] ESP_GATTC_DISCONNECT_EVT, reason %d", this->address_str().c_str(), param->disconnect.reason);
+      for (auto &svc : this->services_)
+        delete svc;  // NOLINT(cppcoreguidelines-owning-memory)
+      this->services_.clear();
+      this->set_state(espbt::ClientState::IDLE);
+      break;
+    }
+    case ESP_GATTC_SEARCH_RES_EVT: {
+      BLEService *ble_service = new BLEService();  // NOLINT(cppcoreguidelines-owning-memory)
+      ble_service->uuid = espbt::ESPBTUUID::from_uuid(param->search_res.srvc_id.uuid);
+      ble_service->start_handle = param->search_res.start_handle;
+      ble_service->end_handle = param->search_res.end_handle;
+      ble_service->client = this;
+      this->services_.push_back(ble_service);
+      break;
+    }
+    case ESP_GATTC_SEARCH_CMPL_EVT: {
+      ESP_LOGV(TAG, "[%s] ESP_GATTC_SEARCH_CMPL_EVT", this->address_str().c_str());
+      for (auto &svc : this->services_) {
+        ESP_LOGI(TAG, "Service UUID: %s", svc->uuid.to_string().c_str());
+        ESP_LOGI(TAG, "  start_handle: 0x%x  end_handle: 0x%x", svc->start_handle, svc->end_handle);
+        svc->parse_characteristics();
+      }
+      this->set_state(espbt::ClientState::CONNECTED);
+      this->state_ = espbt::ClientState::ESTABLISHED;
+      break;
+    }
+    case ESP_GATTC_REG_FOR_NOTIFY_EVT: {
+      auto *descr = this->get_config_descriptor(param->reg_for_notify.handle);
+      if (descr == nullptr) {
+        ESP_LOGW(TAG, "No descriptor found for notify of handle 0x%x", param->reg_for_notify.handle);
+        break;
+      }
+      if (descr->uuid.get_uuid().len != ESP_UUID_LEN_16 ||
+          descr->uuid.get_uuid().uuid.uuid16 != ESP_GATT_UUID_CHAR_CLIENT_CONFIG) {
+        ESP_LOGW(TAG, "Handle 0x%x (uuid %s) is not a client config char uuid", param->reg_for_notify.handle,
+                 descr->uuid.to_string().c_str());
+        break;
+      }
+      uint16_t notify_en = 1;
+      auto status =
+          esp_ble_gattc_write_char_descr(this->gattc_if_, this->conn_id_, descr->handle, sizeof(notify_en),
+                                         (uint8_t *) &notify_en, ESP_GATT_WRITE_TYPE_RSP, ESP_GATT_AUTH_REQ_NONE);
+      if (status) {
+        ESP_LOGW(TAG, "esp_ble_gattc_write_char_descr error, status=%d", status);
+      }
+      break;
+    }
+
+    default:
+      break;
+  }
+}
+
+void BLEClientBase::gap_event_handler(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_param_t *param) {
+  switch (event) {
+    // This event is sent by the server when it requests security
+    case ESP_GAP_BLE_SEC_REQ_EVT:
+      ESP_LOGV(TAG, "ESP_GAP_BLE_SEC_REQ_EVT %x", event);
+      esp_ble_gap_security_rsp(param->ble_security.ble_req.bd_addr, true);
+      break;
+    // This event is sent once authentication has completed
+    case ESP_GAP_BLE_AUTH_CMPL_EVT:
+      esp_bd_addr_t bd_addr;
+      memcpy(bd_addr, param->ble_security.auth_cmpl.bd_addr, sizeof(esp_bd_addr_t));
+      ESP_LOGI(TAG, "auth complete. remote BD_ADDR: %s", format_hex(bd_addr, 6).c_str());
+      if (!param->ble_security.auth_cmpl.success) {
+        ESP_LOGE(TAG, "auth fail reason = 0x%x", param->ble_security.auth_cmpl.fail_reason);
+      } else {
+        ESP_LOGV(TAG, "auth success. address type = %d auth mode = %d", param->ble_security.auth_cmpl.addr_type,
+                 param->ble_security.auth_cmpl.auth_mode);
+      }
+      break;
+    // There are other events we'll want to implement at some point to support things like pass key
+    // https://github.com/espressif/esp-idf/blob/cba69dd088344ed9d26739f04736ae7a37541b3a/examples/bluetooth/bluedroid/ble/gatt_security_client/tutorial/Gatt_Security_Client_Example_Walkthrough.md
+    default:
+      break;
+  }
+}
+
+// Parse GATT values into a float for a sensor.
+// Ref: https://www.bluetooth.com/specifications/assigned-numbers/format-types/
+float BLEClientBase::parse_char_value(uint8_t *value, uint16_t length) {
+  // A length of one means a single octet value.
+  if (length == 0)
+    return 0;
+  if (length == 1)
+    return (float) ((uint8_t) value[0]);
+
+  switch (value[0]) {
+    case 0x1:  // boolean.
+    case 0x2:  // 2bit.
+    case 0x3:  // nibble.
+    case 0x4:  // uint8.
+      return (float) ((uint8_t) value[1]);
+    case 0x5:  // uint12.
+    case 0x6:  // uint16.
+      if (length > 2) {
+        return (float) encode_uint16(value[1], value[2]);
+      }
+    case 0x7:  // uint24.
+      if (length > 3) {
+        return (float) encode_uint24(value[1], value[2], value[3]);
+      }
+    case 0x8:  // uint32.
+      if (length > 4) {
+        return (float) encode_uint32(value[1], value[2], value[3], value[4]);
+      }
+    case 0xC:  // int8.
+      return (float) ((int8_t) value[1]);
+    case 0xD:  // int12.
+    case 0xE:  // int16.
+      if (length > 2) {
+        return (float) ((int16_t)(value[1] << 8) + (int16_t) value[2]);
+      }
+    case 0xF:  // int24.
+      if (length > 3) {
+        return (float) ((int32_t)(value[1] << 16) + (int32_t)(value[2] << 8) + (int32_t)(value[3]));
+      }
+    case 0x10:  // int32.
+      if (length > 4) {
+        return (float) ((int32_t)(value[1] << 24) + (int32_t)(value[2] << 16) + (int32_t)(value[3] << 8) +
+                        (int32_t)(value[4]));
+      }
+  }
+  ESP_LOGW(TAG, "Cannot parse characteristic value of type 0x%x length %d", value[0], length);
+  return NAN;
+}
+
+BLEService *BLEClientBase::get_service(espbt::ESPBTUUID uuid) {
+  for (auto *svc : this->services_) {
+    if (svc->uuid == uuid)
+      return svc;
+  }
+  return nullptr;
+}
+
+BLEService *BLEClientBase::get_service(uint16_t uuid) { return this->get_service(espbt::ESPBTUUID::from_uint16(uuid)); }
+
+BLECharacteristic *BLEClientBase::get_characteristic(espbt::ESPBTUUID service, espbt::ESPBTUUID chr) {
+  auto *svc = this->get_service(service);
+  if (svc == nullptr)
+    return nullptr;
+  return svc->get_characteristic(chr);
+}
+
+BLECharacteristic *BLEClientBase::get_characteristic(uint16_t service, uint16_t chr) {
+  return this->get_characteristic(espbt::ESPBTUUID::from_uint16(service), espbt::ESPBTUUID::from_uint16(chr));
+}
+
+BLECharacteristic *BLEClientBase::get_characteristic(uint16_t handle) {
+  for (auto *svc : this->services_) {
+    for (auto *chr : svc->characteristics) {
+      if (chr->handle == handle)
+        return chr;
+    }
+  }
+  return nullptr;
+}
+
+BLEDescriptor *BLEClientBase::get_config_descriptor(uint16_t handle) {
+  auto *chr = this->get_characteristic(handle);
+  if (chr != nullptr) {
+    for (auto &desc : chr->descriptors) {
+      if (desc->uuid == espbt::ESPBTUUID::from_uint16(0x2902))
+        return desc;
+    }
+  }
+  return nullptr;
+}
+
+BLEDescriptor *BLEClientBase::get_descriptor(espbt::ESPBTUUID service, espbt::ESPBTUUID chr, espbt::ESPBTUUID descr) {
+  auto *svc = this->get_service(service);
+  if (svc == nullptr)
+    return nullptr;
+  auto *ch = svc->get_characteristic(chr);
+  if (ch == nullptr)
+    return nullptr;
+  return ch->get_descriptor(descr);
+}
+
+BLEDescriptor *BLEClientBase::get_descriptor(uint16_t service, uint16_t chr, uint16_t descr) {
+  return this->get_descriptor(espbt::ESPBTUUID::from_uint16(service), espbt::ESPBTUUID::from_uint16(chr),
+                              espbt::ESPBTUUID::from_uint16(descr));
+}
+
+BLEDescriptor *BLEClientBase::get_descriptor(uint16_t handle) {
+  for (auto *svc : this->services_) {
+    for (auto *chr : svc->characteristics) {
+      for (auto *desc : chr->descriptors) {
+        if (desc->handle == handle)
+          return desc;
+      }
+    }
+  }
+  return nullptr;
+}
+
+}  // namespace esp32_ble_client
+}  // namespace esphome
+
+#endif  // USE_ESP32

esphome/components/esp32_ble_client/ble_client_base.h

@@ -0,0 +1,72 @@
+#pragma once
+
+#ifdef USE_ESP32
+
+#include "esphome/components/esp32_ble_tracker/esp32_ble_tracker.h"
+#include "esphome/core/component.h"
+
+#include "ble_service.h"
+
+#include <array>
+#include <string>
+
+#include <esp_bt_defs.h>
+#include <esp_gap_ble_api.h>
+#include <esp_gatt_common_api.h>
+#include <esp_gattc_api.h>
+
+namespace esphome {
+namespace esp32_ble_client {
+
+namespace espbt = esphome::esp32_ble_tracker;
+
+class BLEClientBase : public espbt::ESPBTClient, public Component {
+ public:
+  void setup() override;
+  void loop() override;
+  float get_setup_priority() const override;
+
+  bool parse_device(const espbt::ESPBTDevice &device) override;
+  void on_scan_end() override {}
+  void gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if,
+                           esp_ble_gattc_cb_param_t *param) override;
+  void gap_event_handler(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_param_t *param) override;
+  void connect() override;
+
+  void set_address(uint64_t address) { this->address_ = address; }
+  std::string address_str() const;
+
+  BLEService *get_service(espbt::ESPBTUUID uuid);
+  BLEService *get_service(uint16_t uuid);
+  BLECharacteristic *get_characteristic(espbt::ESPBTUUID service, espbt::ESPBTUUID chr);
+  BLECharacteristic *get_characteristic(uint16_t service, uint16_t chr);
+  BLECharacteristic *get_characteristic(uint16_t handle);
+  BLEDescriptor *get_descriptor(espbt::ESPBTUUID service, espbt::ESPBTUUID chr, espbt::ESPBTUUID descr);
+  BLEDescriptor *get_descriptor(uint16_t service, uint16_t chr, uint16_t descr);
+  BLEDescriptor *get_descriptor(uint16_t handle);
+  // Get the configuration descriptor for the given characteristic handle.
+  BLEDescriptor *get_config_descriptor(uint16_t handle);
+
+  float parse_char_value(uint8_t *value, uint16_t length);
+
+  int get_gattc_if() const { return this->gattc_if_; }
+  uint8_t *get_remote_bda() { return this->remote_bda_; }
+  esp_ble_addr_type_t get_remote_addr_type() const { return this->remote_addr_type_; }
+  uint16_t get_conn_id() const { return this->conn_id_; }
+  uint64_t get_address() const { return this->address_; }
+
+ protected:
+  int gattc_if_;
+  esp_bd_addr_t remote_bda_;
+  esp_ble_addr_type_t remote_addr_type_;
+  uint16_t conn_id_;
+  uint64_t address_;
+  uint16_t mtu_{23};
+
+  std::vector<BLEService *> services_;
+};
+
+}  // namespace esp32_ble_client
+}  // namespace esphome
+
+#endif  // USE_ESP32

esphome/components/esp32_ble_client/ble_descriptor.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#ifdef USE_ESP32
+
+#include "esphome/components/esp32_ble_tracker/esp32_ble_tracker.h"
+
+namespace esphome {
+namespace esp32_ble_client {
+
+namespace espbt = esphome::esp32_ble_tracker;
+
+class BLECharacteristic;
+
+class BLEDescriptor {
+ public:
+  espbt::ESPBTUUID uuid;
+  uint16_t handle;
+
+  BLECharacteristic *characteristic;
+};
+
+}  // namespace esp32_ble_client
+}  // namespace esphome
+
+#endif  // USE_ESP32

esphome/components/esp32_ble_client/ble_service.cpp

@@ -0,0 +1,66 @@
+#include "ble_service.h"
+#include "ble_client_base.h"
+
+#include "esphome/core/log.h"
+
+#ifdef USE_ESP32
+
+namespace esphome {
+namespace esp32_ble_client {
+
+static const char *const TAG = "esp32_ble_client.service";
+
+BLECharacteristic *BLEService::get_characteristic(espbt::ESPBTUUID uuid) {
+  for (auto &chr : this->characteristics) {
+    if (chr->uuid == uuid)
+      return chr;
+  }
+  return nullptr;
+}
+
+BLECharacteristic *BLEService::get_characteristic(uint16_t uuid) {
+  return this->get_characteristic(espbt::ESPBTUUID::from_uint16(uuid));
+}
+
+BLEService::~BLEService() {
+  for (auto &chr : this->characteristics)
+    delete chr;  // NOLINT(cppcoreguidelines-owning-memory)
+}
+
+void BLEService::parse_characteristics() {
+  uint16_t offset = 0;
+  esp_gattc_char_elem_t result;
+
+  while (true) {
+    uint16_t count = 1;
+    esp_gatt_status_t status =
+        esp_ble_gattc_get_all_char(this->client->get_gattc_if(), this->client->get_conn_id(), this->start_handle,
+                                   this->end_handle, &result, &count, offset);
+    if (status == ESP_GATT_INVALID_OFFSET || status == ESP_GATT_NOT_FOUND) {
+      break;
+    }
+    if (status != ESP_GATT_OK) {
+      ESP_LOGW(TAG, "esp_ble_gattc_get_all_char error, status=%d", status);
+      break;
+    }
+    if (count == 0) {
+      break;
+    }
+
+    BLECharacteristic *characteristic = new BLECharacteristic();  // NOLINT(cppcoreguidelines-owning-memory)
+    characteristic->uuid = espbt::ESPBTUUID::from_uuid(result.uuid);
+    characteristic->properties = result.properties;
+    characteristic->handle = result.char_handle;
+    characteristic->service = this;
+    this->characteristics.push_back(characteristic);
+    ESP_LOGI(TAG, " characteristic %s, handle 0x%x, properties 0x%x", characteristic->uuid.to_string().c_str(),
+             characteristic->handle, characteristic->properties);
+    characteristic->parse_descriptors();
+    offset++;
+  }
+}
+
+}  // namespace esp32_ble_client
+}  // namespace esphome
+
+#endif  // USE_ESP32

esphome/components/esp32_ble_client/ble_service.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#ifdef USE_ESP32
+
+#include "esphome/components/esp32_ble_tracker/esp32_ble_tracker.h"
+
+#include "ble_characteristic.h"
+
+namespace esphome {
+namespace esp32_ble_client {
+
+namespace espbt = esphome::esp32_ble_tracker;
+
+class BLEClientBase;
+
+class BLEService {
+ public:
+  ~BLEService();
+  espbt::ESPBTUUID uuid;
+  uint16_t start_handle;
+  uint16_t end_handle;
+  std::vector<BLECharacteristic *> characteristics;
+  BLEClientBase *client;
+  void parse_characteristics();
+  BLECharacteristic *get_characteristic(espbt::ESPBTUUID uuid);
+  BLECharacteristic *get_characteristic(uint16_t uuid);
+};
+
+}  // namespace esp32_ble_client
+}  // namespace esphome
+
+#endif  // USE_ESP32