From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
This reads the database hash if available and compares to the existing
value, if it matches consider the discovery is completed.
---
src/shared/gatt-client.c | 177 +++++++++++++++++++++++++++++++++------
1 file changed, 152 insertions(+), 25 deletions(-)
diff --git a/src/shared/gatt-client.c b/src/shared/gatt-client.c
index 3c2aa293b..d5f9b1294 100644
--- a/src/shared/gatt-client.c
+++ b/src/shared/gatt-client.c
@@ -325,6 +325,7 @@ struct discovery_op {
struct queue *pending_chrcs;
struct queue *ext_prop_desc;
struct gatt_db_attribute *cur_svc;
+ struct gatt_db_attribute *hash;
bool success;
uint16_t start;
uint16_t end;
@@ -349,11 +350,19 @@ static void discovery_op_free(struct discovery_op *op)
free(op);
}
+static bool read_db_hash(struct discovery_op *op);
+
static void discovery_op_complete(struct discovery_op *op, bool success,
uint8_t err)
{
const struct queue_entry *svc;
+ op->success = success;
+
+ /* Read database hash if discovery has been successful */
+ if (success && read_db_hash(op))
+ return;
+
/*
* Unregister remove callback so it is not called when clearing unused
* range.
@@ -380,7 +389,6 @@ static void discovery_op_complete(struct discovery_op *op, bool success,
if (op->last != UINT16_MAX)
gatt_db_clear_range(op->client->db, op->last + 1, UINT16_MAX);
- op->success = success;
op->complete_func(op, success, err);
}
@@ -1249,6 +1257,139 @@ static void notify_client_ready(struct bt_gatt_client *client, bool success,
bt_gatt_client_unref(client);
}
+static void discover_all(struct discovery_op *op)
+{
+ struct bt_gatt_client *client = op->client;
+
+ client->discovery_req = bt_gatt_discover_all_primary_services(
+ client->att, NULL,
+ discover_primary_cb,
+ discovery_op_ref(op),
+ discovery_op_unref);
+ if (client->discovery_req)
+ return;
+
+ util_debug(client->debug_callback, client->debug_data,
+ "Failed to initiate primary service discovery");
+
+ client->in_init = false;
+ notify_client_ready(client, false, BT_ATT_ERROR_UNLIKELY);
+
+ discovery_op_unref(op);
+}
+
+static void db_hash_write_value_cb(struct gatt_db_attribute *attrib,
+ int err, void *user_data)
+{
+ struct bt_gatt_client *client = user_data;
+
+ util_debug(client->debug_callback, client->debug_data,
+ "Value set status: %d", err);
+}
+
+static void db_hash_read_value_cb(struct gatt_db_attribute *attrib,
+ int err, const uint8_t *value,
+ size_t length, void *user_data)
+{
+ const uint8_t **hash = user_data;
+
+ if (err || (length != 16))
+ return;
+
+ *hash = value;
+}
+
+static void db_hash_read_cb(bool success, uint8_t att_ecode,
+ struct bt_gatt_result *result,
+ void *user_data)
+{
+ struct discovery_op *op = user_data;
+ struct bt_gatt_client *client = op->client;
+ const uint8_t *hash = NULL, *value;
+ uint16_t len, handle;
+ struct bt_gatt_iter iter;
+
+ if (!success)
+ goto discover;
+
+ bt_gatt_iter_init(&iter, result);
+ bt_gatt_iter_next_read_by_type(&iter, &handle, &len, &value);
+
+ util_debug(client->debug_callback, client->debug_data,
+ "DB Hash found: handle 0x%04x length 0x%04x",
+ handle, len);
+
+ if (len != 16)
+ goto discover;
+
+ /* Read stored value in the db */
+ gatt_db_attribute_read(op->hash, 0, BT_ATT_OP_READ_REQ, NULL,
+ db_hash_read_value_cb, &hash);
+
+ /* Check if the has has changed since last time */
+ if (hash && !memcmp(hash, value, len)) {
+ util_debug(client->debug_callback, client->debug_data,
+ "DB Hash match: skipping discovery");
+ queue_remove_all(op->pending_svcs, NULL, NULL, NULL);
+ discovery_op_complete(op, true, 0);
+ return;
+ }
+
+ util_debug(client->debug_callback, client->debug_data,
+ "DB Hash value:");
+ util_hexdump(' ', value, len, client->debug_callback,
+ client->debug_data);
+
+ /* Store the new hash in the db */
+ gatt_db_attribute_write(op->hash, 0, value, len, 0, NULL,
+ db_hash_write_value_cb, client);
+
+discover:
+ if (!op->success) {
+ discover_all(op);
+ return;
+ }
+
+ discovery_op_complete(op, true, 0);
+}
+
+static void get_first_attribute(struct gatt_db_attribute *attrib,
+ void *user_data)
+{
+ struct gatt_db_attribute **stored = user_data;
+
+ if (*stored)
+ return;
+
+ *stored = attrib;
+}
+
+static bool read_db_hash(struct discovery_op *op)
+{
+ struct bt_gatt_client *client = op->client;
+ bt_uuid_t uuid;
+
+ /* Check if hash was already read */
+ if (op->hash)
+ return false;
+
+ bt_uuid16_create(&uuid, GATT_CHARAC_DB_HASH);
+ gatt_db_find_by_type(client->db, 0x0001, 0xffff, &uuid,
+ get_first_attribute, &op->hash);
+ if (!op->hash)
+ return false;
+
+ if (!bt_gatt_read_by_type(client->att, 0x0001, 0xffff, &uuid,
+ db_hash_read_cb,
+ discovery_op_ref(op),
+ discovery_op_unref)) {
+ discovery_op_unref(op);
+ return false;
+ }
+
+ return true;
+}
+
static void exchange_mtu_cb(bool success, uint8_t att_ecode, void *user_data)
{
struct discovery_op *op = user_data;
@@ -1282,21 +1423,12 @@ static void exchange_mtu_cb(bool success, uint8_t att_ecode, void *user_data)
bt_att_get_mtu(client->att));
discover:
- client->discovery_req = bt_gatt_discover_all_primary_services(
- client->att, NULL,
- discover_primary_cb,
- discovery_op_ref(op),
- discovery_op_unref);
- if (client->discovery_req)
+ if (read_db_hash(op)) {
+ op->success = false;
return;
+ }
- util_debug(client->debug_callback, client->debug_data,
- "Failed to initiate primary service discovery");
-
- client->in_init = false;
- notify_client_ready(client, false, att_ecode);
-
- discovery_op_unref(op);
+ discover_all(op);
}
struct service_changed_op {
@@ -1491,17 +1623,6 @@ static unsigned int register_notify(struct bt_gatt_client *client,
return notify_data->id;
}
-static void get_first_attribute(struct gatt_db_attribute *attrib,
- void *user_data)
-{
- struct gatt_db_attribute **stored = user_data;
-
- if (*stored)
- return;
-
- *stored = attrib;
-}
-
static void service_changed_register_cb(uint16_t att_ecode, void *user_data)
{
bool success;
@@ -1747,6 +1868,11 @@ static bool gatt_client_init(struct bt_gatt_client *client, uint16_t mtu)
return true;
discover:
+ if (read_db_hash(op)) {
+ op->success = false;
+ goto done;
+ }
+
client->discovery_req = bt_gatt_discover_all_primary_services(
client->att, NULL,
discover_primary_cb,
@@ -1757,6 +1883,7 @@ discover:
return false;
}
+done:
client->in_init = true;
return true;
}
--
2.17.2
