nimble/eatt: Introduce handling multiple EATT in event function

Add handling for multiple EATT instances
in ble_l2cap_event_fn(). Improve logging
by adding infomation with event and cid.

Author: szymon-czapracki

nimble/host/src/ble_eatt.c

@@ -250,35 +250,65 @@ ble_eatt_l2cap_event_fn(struct ble_l2cap_event *event, void *arg)
 
     switch (event->type) {
     case BLE_L2CAP_EVENT_COC_CONNECTED:
-        BLE_EATT_LOG_DEBUG("eatt: Connected \n");
+        BLE_EATT_LOG_DEBUG("eatt: Connected event | conn_handle: %d | scid: %d | dcid: %d\n",
+                            event->connect.conn_handle, event->connect.chan->scid,
+                            event->connect.chan->dcid);
+
         if (event->connect.status) {
+            BLE_EATT_LOG_ERROR("eatt: Connected event status: %d \n");
             ble_eatt_free(eatt);
             return 0;
         }
+
         eatt->chan = event->connect.chan;
+
+        /* Increase used channel number on connected event */
+        eatt->chan_num++;
+
         break;
     case BLE_L2CAP_EVENT_COC_DISCONNECTED:
-        BLE_EATT_LOG_DEBUG("eatt: Disconnected \n");
-        ble_eatt_free(eatt);
+        BLE_EATT_LOG_DEBUG("eatt: Disconnected event | conn_handle: %d | scid: %d | dcid: %d\n",
+                            event->accept.conn_handle, event->accept.chan->scid,
+                            event->accept.chan->dcid);
+
+        eatt = ble_eatt_find(event->disconnect.conn_handle,
+                             event->disconnect.chan->scid);
+        if (!eatt) {
+            BLE_EATT_LOG_ERROR("eatt: Disconnected event | No eatt found\n");
+            return 0;
+        }
+
+        /* Decrease number of channels on disconnect event
+         * If no channels are left - free the resources
+         */
+        eatt->chan--;
+
+        if (eatt->chan == 0) {
+            ble_eatt_free(eatt);
+        }
         break;
     case BLE_L2CAP_EVENT_COC_ACCEPT:
-        BLE_EATT_LOG_DEBUG("eatt: Accept request\n");
-        eatt = ble_eatt_find_by_conn_handle(event->accept.conn_handle);
-        if (eatt) {
-            /* For now we accept only one additional coc channel per ACL
-             * TODO: improve it
-             */
-            return BLE_HS_ENOMEM;
-        }
+        BLE_EATT_LOG_DEBUG("eatt: Accepted | conn_handle: %d | scid: %d | dcid: %d\n",
+                            event->accept.conn_handle, event->accept.chan->scid,
+                            event->accept.chan->dcid);
 
-        eatt = ble_eatt_alloc();
+        /* Lookup if EATT already exists for this connection */
+        eatt = ble_eatt_find_by_conn_handle(event->accept.conn_handle);
         if (!eatt) {
-            return BLE_HS_ENOMEM;
+            eatt = ble_eatt_alloc();
+            eatt->chan_num++;
+        } else {
+            /* Check for free resources for this connection */
+            free_channels = MYNEWT_VAL(BLE_EATT_CHAN_PER_CONN) - ble_eatt_used_channels(event->accept.conn_handle);
+
+            if (free_channels == 0) {
+                BLE_EATT_LOG_ERROR("eatt: Accepted | No free channel slots\n");
+                ble_eatt_free(eatt);
+                return BLE_HS_ENOMEM;
+            }
+            eatt->chan_num++;
         }
 
-        eatt->conn_handle = event->accept.conn_handle;
-        event->accept.chan->cb_arg = eatt;
-
         rc = ble_eatt_prepare_rx_sdu(event->accept.chan);
         if (rc) {
             ble_eatt_free(eatt);
@@ -287,9 +317,23 @@ ble_eatt_l2cap_event_fn(struct ble_l2cap_event *event, void *arg)
 
         break;
     case BLE_L2CAP_EVENT_COC_TX_UNSTALLED:
+        eatt = ble_eatt_find(event->tx_unstalled.conn_handle,
+                             event->tx_unstalled.chan->scid);
+        if (!eatt) {
+            BLE_EATT_LOG_ERROR("eatt: Unstalled event | EATT not found\n");
+            return 0;
+        }
+
         ble_npl_eventq_put(ble_hs_evq_get(), &eatt->wakeup_ev);
         break;
     case BLE_L2CAP_EVENT_COC_DATA_RECEIVED:
+        eatt = ble_eatt_find(event->receive.conn_handle,
+                             event->receive.chan->scid);
+        if (!eatt) {
+            BLE_EATT_LOG_ERROR("eatt: Data rx event | EATT not found\n");
+            return 0;
+        }
+
         assert(eatt->chan == event->receive.chan);
         opcode = event->receive.sdu_rx->om_data[0];
         if (ble_eatt_supported_rsp(opcode)) {