Bluetooth: host: Save CCC data on pairing complete

Fixes issue #39989.

Save CCC data on pairing complete by replacing private addresses
for the just bonded device with its public address in CCC attributes'
CFG arrays. This is then followed by calls to bt_gatt_store_ccc
and bt_gatt_store_cf for the just bonded device.

Signed-off-by: Jim Benjamin Luther <[email protected]>

Author: jilu-ot

subsys/bluetooth/host/gatt.c

@@ -868,6 +868,103 @@ static ssize_t sf_read(struct bt_conn *conn, const struct bt_gatt_attr *attr,
 #endif /* CONFIG_BT_EATT */
 #endif /* CONFIG_BT_GATT_CACHING */
 
+static int bt_gatt_store_cf(struct bt_conn *conn)
+{
+#if defined(CONFIG_BT_GATT_CACHING)
+	struct gatt_cf_cfg *cfg;
+	char key[BT_SETTINGS_KEY_MAX];
+	char *str;
+	size_t len;
+	int err;
+
+	cfg = find_cf_cfg(conn);
+	if (!cfg) {
+		/* No cfg found, just clear it */
+		BT_DBG("No config for CF");
+		str = NULL;
+		len = 0;
+	} else {
+		str = (char *)cfg->data;
+		len = sizeof(cfg->data);
+
+		if (conn->id) {
+			char id_str[4];
+
+			u8_to_dec(id_str, sizeof(id_str), conn->id);
+			bt_settings_encode_key(key, sizeof(key), "cf",
+					       &conn->le.dst, id_str);
+		}
+	}
+
+	if (!cfg || !conn->id) {
+		bt_settings_encode_key(key, sizeof(key), "cf",
+				       &conn->le.dst, NULL);
+	}
+
+	err = settings_save_one(key, str, len);
+	if (err) {
+		BT_ERR("Failed to store Client Features (err %d)", err);
+		return err;
+	}
+
+	BT_DBG("Stored CF for %s (%s)", bt_addr_le_str(&conn->le.dst), log_strdup(key));
+#endif /* CONFIG_BT_GATT_CACHING */
+	return 0;
+
+}
+
+#if defined(CONFIG_BT_SETTINGS) && defined(CONFIG_BT_SMP) && defined(CONFIG_BT_GATT_CLIENT)
+/** Struct used to store both the id and the random address of a device when replacing
+ * random addresses in the ccc attribute's cfg array with the device's id address after
+ * pairing complete.
+ */
+struct addr_match {
+	const bt_addr_le_t *private_addr;
+	const bt_addr_le_t *id_addr;
+};
+
+static uint8_t convert_to_id_on_match(const struct bt_gatt_attr *attr,
+				      uint16_t handle, void *user_data)
+{
+	struct _bt_gatt_ccc *ccc;
+	struct addr_match *match = user_data;
+
+	/* Check if attribute is a CCC */
+	if (attr->write != bt_gatt_attr_write_ccc) {
+		return BT_GATT_ITER_CONTINUE;
+	}
+
+	ccc = attr->user_data;
+
+	/* Copy the device's id address to the config's address if the config's address is the
+	 * same as the device's private address
+	 */
+	for (size_t i = 0; i < ARRAY_SIZE(ccc->cfg); i++) {
+		if (bt_addr_le_cmp(&ccc->cfg[i].peer, match->private_addr) == 0) {
+			bt_addr_le_copy(&ccc->cfg[i].peer, match->id_addr);
+		}
+	}
+
+	return BT_GATT_ITER_CONTINUE;
+}
+
+static void bt_gatt_identity_resolved(struct bt_conn *conn, const bt_addr_le_t *private_addr,
+				      const bt_addr_le_t *id_addr)
+{
+	/* Update the ccc cfg addresses */
+	struct addr_match user_data = {
+		.private_addr = private_addr,
+		.id_addr      = id_addr
+	};
+
+	bt_gatt_foreach_attr(0x0001, 0xffff, convert_to_id_on_match, &user_data);
+
+	/* Store the ccc and cf data */
+	bt_gatt_store_ccc(conn->id, &(conn->le.dst));
+	bt_gatt_store_cf(conn);
+}
+#endif /* CONFIG_BT_SETTINGS && CONFIG_BT_SMP && CONFIG_BT_GATT_CLIENT */
+
 BT_GATT_SERVICE_DEFINE(_1_gatt_svc,
 	BT_GATT_PRIMARY_SERVICE(BT_UUID_GATT),
 #if defined(CONFIG_BT_GATT_SERVICE_CHANGED)
@@ -4991,6 +5088,18 @@ void bt_gatt_connected(struct bt_conn *conn)
 
 #if defined(CONFIG_BT_GATT_CLIENT)
 	add_subscriptions(conn);
+
+#if defined(CONFIG_BT_SETTINGS) && defined(CONFIG_BT_SMP)
+	static struct bt_conn_cb gatt_conn_cb = {
+		.identity_resolved = bt_gatt_identity_resolved,
+	};
+
+	/* Register the gatt module for connection callbacks so it can be
+	 * notified when pairing has completed. This is used to enable CCC and
+	 * CF storage on pairing complete.
+	 */
+	bt_conn_cb_register(&gatt_conn_cb);
+#endif /* CONFIG_BT_SETTINGS && CONFIG_BT_SMP */
 #endif /* CONFIG_BT_GATT_CLIENT */
 }
 
@@ -5061,51 +5170,6 @@ bool bt_gatt_change_aware(struct bt_conn *conn, bool req)
 #endif
 }
 
-static int bt_gatt_store_cf(struct bt_conn *conn)
-{
-#if defined(CONFIG_BT_GATT_CACHING)
-	struct gatt_cf_cfg *cfg;
-	char key[BT_SETTINGS_KEY_MAX];
-	char *str;
-	size_t len;
-	int err;
-
-	cfg = find_cf_cfg(conn);
-	if (!cfg) {
-		/* No cfg found, just clear it */
-		BT_DBG("No config for CF");
-		str = NULL;
-		len = 0;
-	} else {
-		str = (char *)cfg->data;
-		len = sizeof(cfg->data);
-
-		if (conn->id) {
-			char id_str[4];
-
-			u8_to_dec(id_str, sizeof(id_str), conn->id);
-			bt_settings_encode_key(key, sizeof(key), "cf",
-					       &conn->le.dst, id_str);
-		}
-	}
-
-	if (!cfg || !conn->id) {
-		bt_settings_encode_key(key, sizeof(key), "cf",
-				       &conn->le.dst, NULL);
-	}
-
-	err = settings_save_one(key, str, len);
-	if (err) {
-		BT_ERR("Failed to store Client Features (err %d)", err);
-		return err;
-	}
-
-	BT_DBG("Stored CF for %s (%s)", bt_addr_le_str(&conn->le.dst), log_strdup(key));
-#endif /* CONFIG_BT_GATT_CACHING */
-	return 0;
-
-}
-
 static struct gatt_cf_cfg *find_cf_cfg_by_addr(uint8_t id,
 					       const bt_addr_le_t *addr)
 {