put bonding to-do flags into Connection objects instead of using a heap-allocated queue

Author: dhalbert

ports/nrf/common-hal/_bleio/Connection.c

@@ -46,6 +46,7 @@
 #include "shared-bindings/_bleio/Characteristic.h"
 #include "shared-bindings/_bleio/Service.h"
 #include "shared-bindings/_bleio/UUID.h"
+#include "supervisor/shared/tick.h"
 
 #include "common-hal/_bleio/bonding.h"
 
@@ -93,7 +94,6 @@ bool connection_on_ble_evt(ble_evt_t *ble_evt, void *self_in) {
 
     switch (ble_evt->header.evt_id) {
         case BLE_GAP_EVT_DISCONNECTED:
-            CONNECTION_DEBUG_PRINTF("BLE_GAP_EVT_DISCONNECTED\n");
             // Adapter.c does the work for this event.
             break;
 
@@ -130,7 +130,12 @@ bool connection_on_ble_evt(ble_evt_t *ble_evt, void *self_in) {
                 self->pair_status == PAIR_PAIRED &&
                 ble_evt->evt.gatts_evt.params.write.uuid.type == BLE_UUID_TYPE_BLE &&
                 ble_evt->evt.gatts_evt.params.write.uuid.uuid == 0x2902) {
-                bonding_save_cccd_info(self->is_central, self->conn_handle, self->ediv);
+                //
+                // Save sys_attr data (CCCD state) in bonding area at
+                // next opportunity, but also remember time of this
+                // request, so we can consolidate closely-spaced requests.
+                self->do_bond_cccds = true;
+                self->do_bond_cccds_request_time = supervisor_ticks_ms64();
             }
             break;
 
@@ -194,7 +199,6 @@ bool connection_on_ble_evt(ble_evt_t *ble_evt, void *self_in) {
             break;
         }
         case BLE_GAP_EVT_SEC_PARAMS_REQUEST: {
-            CONNECTION_DEBUG_PRINTF("BLE_GAP_EVT_SEC_PARAMS_REQUEST\n");
             // First time pairing.
             // 1. Either we or peer initiate the process
             // 2. Peer asks for security parameters using BLE_GAP_EVT_SEC_PARAMS_REQUEST.
@@ -227,47 +231,40 @@ bool connection_on_ble_evt(ble_evt_t *ble_evt, void *self_in) {
         }
 
         case BLE_GAP_EVT_LESC_DHKEY_REQUEST:
-            CONNECTION_DEBUG_PRINTF("BLE_GAP_EVT_LESC_DHKEY_REQUEST\n");
             // TODO for LESC pairing:
             // sd_ble_gap_lesc_dhkey_reply(...);
             break;
 
         case BLE_GAP_EVT_AUTH_STATUS: { // 0x19
-            CONNECTION_DEBUG_PRINTF("BLE_GAP_EVT_AUTH_STATUS\n");
             // Key exchange completed.
             ble_gap_evt_auth_status_t* status = &ble_evt->evt.gap_evt.params.auth_status;
             self->sec_status = status->auth_status;
             if (status->auth_status == BLE_GAP_SEC_STATUS_SUCCESS) {
                 self->ediv = self->bonding_keys.own_enc.master_id.ediv;
                 self->pair_status = PAIR_PAIRED;
-                CONNECTION_DEBUG_PRINTF("PAIR_PAIRED\n");
-                bonding_save_keys(self->is_central, self->conn_handle, &self->bonding_keys);
+                // Save keys in bonding area at next opportunity.
+                self->do_bond_keys = true;
             } else {
                 // Inform busy-waiter pairing has failed.
                 self->pair_status = PAIR_NOT_PAIRED;
-                CONNECTION_DEBUG_PRINTF("PAIR_NOT_PAIRED\n");
             }
             break;
         }
 
         case BLE_GAP_EVT_SEC_INFO_REQUEST: { // 0x14
-            CONNECTION_DEBUG_PRINTF("BLE_GAP_EVT_SEC_INFO_REQUEST\n");
             // Peer asks for the stored keys.
             // - load key and return if bonded previously.
             // - Else return NULL --> Initiate key exchange
             ble_gap_evt_sec_info_request_t* sec_info_request = &ble_evt->evt.gap_evt.params.sec_info_request;
             (void) sec_info_request;
             if ( bonding_load_keys(self->is_central, sec_info_request->master_id.ediv, &self->bonding_keys) ) {
-                CONNECTION_DEBUG_PRINTF("keys found\n");
-                uint32_t err_code = sd_ble_gap_sec_info_reply(
+                sd_ble_gap_sec_info_reply(
                     self->conn_handle,
                     &self->bonding_keys.own_enc.enc_info,
                     &self->bonding_keys.peer_id.id_info,
                     NULL);
-                CONNECTION_DEBUG_PRINTF("sd_ble_gap_sec_info_reply err_code: %0lx\n", err_code);
                 self->ediv = self->bonding_keys.own_enc.master_id.ediv;
             } else {
-                CONNECTION_DEBUG_PRINTF("keys not found\n");
                 // We don't have stored keys. Ask for keys.
                 sd_ble_gap_sec_info_reply(self->conn_handle, NULL, NULL, NULL);
             }
@@ -277,8 +274,6 @@ bool connection_on_ble_evt(ble_evt_t *ble_evt, void *self_in) {
         case BLE_GAP_EVT_CONN_SEC_UPDATE: { // 0x1a
             // We get this both on first-time pairing and on subsequent pairings using stored keys.
             ble_gap_conn_sec_t* conn_sec = &ble_evt->evt.gap_evt.params.conn_sec_update.conn_sec;
-            CONNECTION_DEBUG_PRINTF("BLE_GAP_EVT_CONN_SEC_UPDATE, sm: %d, lv: %d\n",
-                                    conn_sec->sec_mode.sm, conn_sec->sec_mode.lv);
             if (conn_sec->sec_mode.sm <= 1 && conn_sec->sec_mode.lv <= 1) {
                 // Security setup did not succeed:
                 // mode 0, level 0 means no access
@@ -289,10 +284,8 @@ bool connection_on_ble_evt(ble_evt_t *ble_evt, void *self_in) {
                 if (bonding_load_cccd_info(self->is_central, self->conn_handle, self->ediv)) {
                     // Did an sd_ble_gatts_sys_attr_set() with the stored sys_attr values.
                     // Not quite paired yet: wait for BLE_GAP_EVT_AUTH_STATUS with BLE_GAP_SEC_STATUS_SUCCESS.
-                    CONNECTION_DEBUG_PRINTF("did bonding_load_cccd_info()\n");
                 } else {
                     // No matching bonding found, so use fresh system attributes.
-                    CONNECTION_DEBUG_PRINTF("bonding_load_cccd_info() failed\n");
                     sd_ble_gatts_sys_attr_set(self->conn_handle, NULL, 0, 0);
                 }
                 self->pair_status = PAIR_PAIRED;
@@ -301,10 +294,8 @@ bool connection_on_ble_evt(ble_evt_t *ble_evt, void *self_in) {
         }
 
         default:
-            CONNECTION_DEBUG_PRINTF("Unhandled event: %04x\n", ble_evt->header.evt_id);
             return false;
     }
-    CONNECTION_DEBUG_PRINTF("Handled event: %04x\n", ble_evt->header.evt_id);
     return true;
 }
 
@@ -590,8 +581,7 @@ STATIC bool discovery_on_ble_evt(ble_evt_t *ble_evt, mp_obj_t payload) {
             break;
 
         default:
-            // For debugging.
-            // mp_printf(&mp_plat_print, "Unhandled discovery event: 0x%04x\n", ble_evt->header.evt_id);
+            // CONNECTION_DEBUG_PRINTF(&mp_plat_print, "Unhandled discovery event: 0x%04x\n", ble_evt->header.evt_id);
             return false;
             break;
     }

ports/nrf/common-hal/_bleio/Connection.h

@@ -57,15 +57,22 @@ typedef struct {
     // The advertising data and scan response buffers are held by us, not by the SD, so we must
     // maintain them and not change it. If we need to change the contents during advertising,
     // there are tricks to get the SD to notice (see DevZone - TBS).
-    // EDIV: Encrypted Diversifier: Identifies LTK during legacy pairing.
     bonding_keys_t bonding_keys;
+    // EDIV: Encrypted Diversifier: Identifies LTK during legacy pairing.
     uint16_t ediv;
     volatile pair_status_t pair_status;
     uint8_t sec_status; // Internal security status.
     mp_obj_t connection_obj;
     ble_drv_evt_handler_entry_t handler_entry;
     ble_gap_conn_params_t conn_params;
     volatile bool conn_params_updating;
+    // Request that CCCD info for this connection be saved.
+    volatile bool do_bond_cccds;
+    // Request that security key info for this connection be saved.
+    volatile bool do_bond_keys;
+    // Time of setting do_bond_ccds: we delay a bit to consolidate multiple CCCD changes
+    // into one write. Time is currently in ticks_ms.
+    uint64_t do_bond_cccds_request_time;
 } bleio_connection_internal_t;
 
 typedef struct {