GATTC notifications support

include/esp32/esp32_bt_internal.h

@@ -41,7 +41,7 @@ void esp32_bt_rlock(void);
 void esp32_bt_runlock(void);
 
 struct os_mbuf;
-char *esp32_bt_mbuf_to_flat(const struct os_mbuf *om, uint16_t *len);
+struct mg_str esp32_bt_mbuf_to_flat(const struct os_mbuf *om);
 
 #ifdef __cplusplus
 }

include/mgos_bt_gattc.h

@@ -69,17 +69,27 @@ struct mgos_bt_gattc_write_result_arg {
 struct mgos_bt_gattc_notify_arg {
   struct mgos_bt_gatt_conn conn; /* Device address */
   uint16_t handle;               /* Characteristic handle  */
+  bool is_indication;            /* True if this is an indication. */
   struct mg_str data;            /* Notification data sent by the server */
 };
 
 bool mgos_bt_gattc_connect(const struct mgos_bt_addr *addr);
+
 bool mgos_bt_gattc_discover(uint16_t conn_id);
+
 bool mgos_bt_gattc_disconnect(uint16_t conn_id);
+
 bool mgos_bt_gattc_read(uint16_t conn_id, uint16_t handle);
-bool mgos_bt_gattc_subscribe(uint16_t conn_id, uint16_t handle);
+
 bool mgos_bt_gattc_write(uint16_t conn_id, uint16_t handle, struct mg_str data,
                          bool resp_required);
 
+// Note that the handle here is the handle of the CCCD for the attribute,
+// not the attribute itself. Usually CCCD immediately follows the attribute
+// so att_handle + 1 is a reasonable guess here.
+bool mgos_bt_gattc_set_notify_mode_cccd(uint16_t conn_id, uint16_t cccd_handle,
+                                        enum mgos_bt_gatt_notify_mode mode);
+
 #ifdef __cplusplus
 }
 #endif

mjs_fs/api_bt_gattc.js

@@ -18,15 +18,14 @@ let GATTC = {
   },
   getWriteResult: function(evdata) { return s2o(evdata, GATTC._wrd); },
 
-  // NB: does not work at present, TODO
-  subscribe: ffi('bool mgos_bt_gattc_subscribe(int, int)'),
+  setNotifyModeCCCD: ffi('bool mgos_bt_gattc_set_notify_mode_cccd(int, int, int)'),
   getNotifyArg: function(evdata) { return s2o(evdata, GATTC._nad); },
 
   disconnect: ffi('bool mgos_bt_gattc_disconnect(int)'),
 
   _cd: ffi('void *mgos_bt_gatt_js_get_conn_def(void)')(),
-  _rrd: ffi('void *mgos_bt_gattc_js_get_read_result_def(void)')(),
-  _wrd: ffi('void *mgos_bt_gattc_js_get_write_result_def(void)')(),
+  _rrd: ffi('void *mgos_bt_gattc_js_get_read_result_arg_def(void)')(),
+  _wrd: ffi('void *mgos_bt_gattc_js_get_write_result_arg_def(void)')(),
   _nad: ffi('void *mgos_bt_gattc_js_get_notify_arg_def(void)')(),
   _drad: ffi('void *mgos_bt_gattc_js_get_discovery_result_arg_def(void)')(),
   _ddad: ffi('void *mgos_bt_gattc_js_get_discovery_done_arg_def(void)')(),
@@ -40,3 +39,7 @@ GATTC.EV_DISCOVERY_DONE = GATTC.EV_GRP + 3;
 GATTC.EV_READ_RESULT = GATTC.EV_GRP + 4;
 GATTC.EV_WRITE_RESULT = GATTC.EV_GRP + 5;
 GATTC.EV_NOTIFY = GATTC.EV_GRP + 6;
+
+GATTC.NOTIFY_MODE_OFF = 0;
+GATTC.NOTIFY_MODE_NOTIFY = 1;
+GATTC.NOTIFY_MODE_INDICATE = 2;

src/esp32/esp32_bt.c

@@ -359,20 +359,19 @@ static void esp32_bt_start(void *arg) {
   (void) arg;
 }
 
-char *esp32_bt_mbuf_to_flat(const struct os_mbuf *om, uint16_t *len) {
-  *len = 0;
-  if (om == NULL) return NULL;
+struct mg_str esp32_bt_mbuf_to_flat(const struct os_mbuf *om) {
+  struct mg_str res = MG_NULL_STR;
+  if (om == NULL) return res;
   char *data = NULL;
   uint16_t data_len = OS_MBUF_PKTLEN(om);
   if (data_len > 0) {
     data = malloc(data_len);
-    if (data == NULL) {
-      return NULL;
-    }
+    if (data == NULL) return res;
     ble_hs_mbuf_to_flat(om, data, data_len, &data_len);
   }
-  *len = data_len;
-  return data;
+  res.p = data;
+  res.len = data_len;
+  return res;
 }
 
 bool mgos_bt_common_init(void) {

src/esp32/esp32_bt_gattc.c

@@ -203,6 +203,21 @@ static int esp32_bt_gattc_event(struct ble_gap_event *ev, void *arg) {
       free(conn);
       break;
     }
+    case BLE_GAP_EVENT_NOTIFY_RX: {
+      struct esp32_bt_gattc_conn *conn =
+          find_conn_by_id(ev->notify_rx.conn_handle);
+      if (conn == NULL) return BLE_ATT_ERR_UNLIKELY;
+      struct mg_str data = esp32_bt_mbuf_to_flat(ev->notify_rx.om);
+      struct mgos_bt_gattc_notify_arg narg = {
+          .conn = conn->gc,
+          .handle = ev->notify_rx.attr_handle,
+          .is_indication = ev->notify_rx.indication,
+          .data = data,
+      };
+      mgos_event_trigger(MGOS_BT_GATTC_EV_NOTIFY, &narg);
+      mg_strfree(&data);
+      break;
+    }
   }
   esp32_bt_runlock();
   return 0;
@@ -234,12 +249,11 @@ static int esp32_bt_gattc_read_cb(uint16_t conn_id,
   struct esp32_bt_gattc_conn *conn = validate_conn(pr->conn);
   if (conn == NULL) return BLE_ATT_ERR_UNLIKELY;
   if (err->status == 0) {
-    uint16_t data_len = 0;
-    char *data = esp32_bt_mbuf_to_flat(attr->om, &data_len);
+    struct mg_str data = esp32_bt_mbuf_to_flat(attr->om);
     LOG(LL_DEBUG,
-        ("READ_PART c %d ah %d len %d", conn_id, pr->handle, data_len));
-    mbuf_append(&pr->data, data, data_len);
-    free(data);
+        ("READ_PART c %d ah %d len %d", conn_id, pr->handle, data.len));
+    mbuf_append(&pr->data, data.p, data.len);
+    mg_strfree(&data);
     return 0;
   }
   SLIST_REMOVE(&conn->pending_reads, pr, esp32_bt_gattc_pending_read, next);
@@ -289,12 +303,6 @@ bool mgos_bt_gattc_read(uint16_t conn_id, uint16_t handle) {
   return res;
 }
 
-bool mgos_bt_gattc_subscribe(uint16_t conn_id, uint16_t handle) {
-  struct esp32_bt_gattc_conn *conn = find_conn_by_id(conn_id);
-  if (conn == NULL) return false;
-  return false;
-}
-
 static int esp32_bt_gattc_write_cb(uint16_t conn_id,
                                    const struct ble_gatt_error *err,
                                    struct ble_gatt_attr *attr, void *arg) {
@@ -340,6 +348,19 @@ bool mgos_bt_gattc_write(uint16_t conn_id, uint16_t handle, struct mg_str data,
   return (ret == 0);
 }
 
+bool mgos_bt_gattc_set_notify_mode_cccd(uint16_t conn_id, uint16_t cccd_handle,
+                                        enum mgos_bt_gatt_notify_mode mode) {
+  struct esp32_bt_gattc_conn *conn = find_conn_by_id(conn_id);
+  if (conn == NULL) return false;
+  uint8_t data[2] = {mode, 0};
+  int ret =
+      ble_gattc_write_no_rsp_flat(conn_id, cccd_handle, data, sizeof(data));
+  if (ret != 0) {
+    LOG(LL_ERROR, ("ret = %d", ret));
+  }
+  return (ret == 0);
+}
+
 static int esp32_bt_gattc_add_disc_result_entry(
     struct esp32_bt_gattc_conn *conn,
     const struct esp32_bt_gattc_disc_result *cdre) {

src/esp32/esp32_bt_gatts.c

@@ -643,12 +643,11 @@ static int esp32_gatts_attr_access_cb(uint16_t ch, uint16_t ah,
     }
     case BLE_GATT_ACCESS_OP_WRITE_CHR:
     case BLE_GATT_ACCESS_OP_WRITE_DSC: {
-      uint16_t data_len = 0;
-      char *data = esp32_bt_mbuf_to_flat(ctxt->om, &data_len);
+      struct mg_str data = esp32_bt_mbuf_to_flat(ctxt->om);
       struct mgos_bt_gatts_write_arg warg = {
           .svc_uuid = sse->se->uuid,
           .handle = ah,
-          .data = mg_mk_str_n(data, data_len),
+          .data = data,
           .trans_id = 0,
           .offset = 0,
           .need_rsp = true,
@@ -677,7 +676,7 @@ static int esp32_gatts_attr_access_cb(uint16_t ch, uint16_t ah,
                        (int) warg.data.len, st));
       }
       res = esp32_gatts_get_att_err(st);
-      free(data);
+      mg_strfree(&data);
       break;
     }
   }

src/mgos_bt_js.c

@@ -139,7 +139,7 @@ const struct mjs_c_struct_member *mgos_bt_gattc_js_get_discovery_done_arg_def(
   return gattc_discovery_done_arg_def;
 }
 
-static const struct mjs_c_struct_member gattc_read_result_def[] = {
+static const struct mjs_c_struct_member gattc_read_result_arg_def[] = {
     {"conn", offsetof(struct mgos_bt_gattc_read_result_arg, conn),
      MJS_STRUCT_FIELD_TYPE_STRUCT, gatt_conn_def},
     {"handle", offsetof(struct mgos_bt_gattc_read_result_arg, handle),
@@ -151,11 +151,12 @@ static const struct mjs_c_struct_member gattc_read_result_def[] = {
     {NULL},
 };
 
-const struct mjs_c_struct_member *mgos_bt_gattc_js_get_read_result_def(void) {
-  return gattc_read_result_def;
+const struct mjs_c_struct_member *mgos_bt_gattc_js_get_read_result_arg_def(
+    void) {
+  return gattc_read_result_arg_def;
 }
 
-static const struct mjs_c_struct_member gattc_write_result_def[] = {
+static const struct mjs_c_struct_member gattc_write_result_arg_def[] = {
     {"conn", offsetof(struct mgos_bt_gattc_write_result_arg, conn),
      MJS_STRUCT_FIELD_TYPE_STRUCT, gatt_conn_def},
     {"handle", offsetof(struct mgos_bt_gattc_write_result_arg, handle),
@@ -165,12 +166,25 @@ static const struct mjs_c_struct_member gattc_write_result_def[] = {
     {NULL},
 };
 
-const struct mjs_c_struct_member *mgos_bt_gattc_js_get_write_result_def(void) {
-  return gattc_write_result_def;
+const struct mjs_c_struct_member *mgos_bt_gattc_js_get_write_result_arg_def(
+    void) {
+  return gattc_write_result_arg_def;
 }
 
+static const struct mjs_c_struct_member gattc_notify_arg_def[] = {
+    {"conn", offsetof(struct mgos_bt_gattc_notify_arg, conn),
+     MJS_STRUCT_FIELD_TYPE_STRUCT, gatt_conn_def},
+    {"handle", offsetof(struct mgos_bt_gattc_notify_arg, handle),
+     MJS_STRUCT_FIELD_TYPE_UINT16, NULL},
+    {"isIndication", offsetof(struct mgos_bt_gattc_notify_arg, is_indication),
+     MJS_STRUCT_FIELD_TYPE_BOOL, NULL},
+    {"data", offsetof(struct mgos_bt_gattc_notify_arg, data),
+     MJS_STRUCT_FIELD_TYPE_MG_STR, NULL},
+    {NULL},
+};
+
 const struct mjs_c_struct_member *mgos_bt_gattc_js_get_notify_arg_def(void) {
-  return gattc_read_result_def; /* Currently they are the same */
+  return gattc_notify_arg_def;
 }
 
 static const struct mjs_c_struct_member gatts_read_arg_def[] = {