Hi Arman,
On 18 November 2014 00:36, Arman Uguray <armansito@xxxxxxxxxxxx> wrote:
> Hi Luiz,
>
>> On Fri, Nov 14, 2014 at 5:51 AM, Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> wrote:
>> Hi Marcin,
>>
>> On Fri, Nov 14, 2014 at 3:13 PM, Marcin Kraglak
>> <marcin.kraglak@xxxxxxxxx> wrote:
>>> Hi Luiz,
>>>
>>> On 14 November 2014 13:44, Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> wrote:
>>>> Hi Marcin,
>>>>
>>>> On Thu, Nov 13, 2014 at 1:27 PM, Marcin Kraglak
>>>> <marcin.kraglak@xxxxxxxxx> wrote:
>>>>> This is exposed to allow client reading characteristic values
>>>>> with known uuid.
>>>>> ---
>>>>> src/shared/gatt-client.c | 271 +++++++++++++++++++++++++++++++++++++++++++++++
>>>>> src/shared/gatt-client.h | 18 ++++
>>>>> 2 files changed, 289 insertions(+)
>>>>>
>>>>> diff --git a/src/shared/gatt-client.c b/src/shared/gatt-client.c
>>>>> index 30b271e..0493b05 100644
>>>>> --- a/src/shared/gatt-client.c
>>>>> +++ b/src/shared/gatt-client.c
>>>>> @@ -44,6 +44,11 @@
>>>>> #define GATT_SVC_UUID 0x1801
>>>>> #define SVC_CHNGD_UUID 0x2a05
>>>>>
>>>>> +static const uint8_t bt_base_uuid[16] = {
>>>>> + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
>>>>> + 0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB
>>>>> +};
>>>>> +
>>>>> struct chrc_data {
>>>>> /* The public characteristic entry. */
>>>>> bt_gatt_characteristic_t chrc_external;
>>>>> @@ -122,6 +127,15 @@ struct bt_gatt_client {
>>>>> bool in_svc_chngd;
>>>>> };
>>>>>
>>>>> +static bool is_bluetooth_uuid(const uint8_t uuid[BT_GATT_UUID_SIZE])
>>>>> +{
>>>>> + if (memcmp(uuid, bt_base_uuid, 2) ||
>>>>> + memcmp(&uuid[4], &bt_base_uuid[4], 12))
>>>>> + return false;
>>>>> +
>>>>> + return true;
>>>>> +}
>>>>> +
>>>>
>>>> Is this really different from uuid_cmp? Perhaps you use set uuid16
>>>> properly it should just do the same you are doing above.
>>> Ok, I'll use it.
>>>>
>>>>> struct notify_data {
>>>>> struct bt_gatt_client *client;
>>>>> bool removed;
>>>>> @@ -2001,6 +2015,263 @@ bool bt_gatt_client_read_long_value(struct bt_gatt_client *client,
>>>>> return true;
>>>>> }
>>>>>
>>>>> +struct read_by_uuid_res {
>>>>> + uint16_t handle;
>>>>> + uint8_t length;
>>>>> + uint8_t *data;
>>>>> + struct read_by_uuid_res *next;
>>>>> +};
>>>>> +
>>>>> +bool read_by_uuid_res_get(struct read_by_uuid_res *result, uint16_t *handle,
>>>>> + uint8_t *length, uint8_t **data)
>>>>> +{
>>>>> + if (!result)
>>>>> + return false;
>>>>> +
>>>>> + *length = result->length;
>>>>> + *handle = result->handle;
>>>>> + *data = result->data;
>>>>> +
>>>>> + return true;
>>>>> +}
>>>>> +
>>>>> +struct read_by_uuid_res *read_by_uuid_res_next(struct read_by_uuid_res *result)
>>>>> +{
>>>>> + if (!result)
>>>>> + return NULL;
>>>>> +
>>>>> + return result->next;
>>>>> +}
>>>>> +
>>>>> +struct read_by_uuid_op {
>>>>> + struct bt_gatt_client *client;
>>>>> + bt_gatt_client_read_by_uuid_callback_t callback;
>>>>> + int ref_count;
>>>>> + uint16_t start_handle;
>>>>> + uint16_t end_handle;
>>>>> + uint8_t uuid[BT_GATT_UUID_SIZE];
>>>>> + struct read_by_uuid_res *result_head;
>>>>> + struct read_by_uuid_res *result_tail;
>>>>> + void *user_data;
>>>>> + bt_gatt_client_destroy_func_t destroy;
>>>>> +};
>>>>
>>>> Im not really sure this lists are really helping us, perhaps this is
>>>> the effect of using iterators in the API but that seems to create
>>>> duplicated code.
>>>>
>>>>> +static bool append_read_by_uuid_result(struct read_by_uuid_op *op,
>>>>> + uint16_t handle, uint16_t length,
>>>>> + const uint8_t *data)
>>>>> +{
>>>>> + struct read_by_uuid_res *result;
>>>>> +
>>>>> + result = new0(struct read_by_uuid_res, 1);
>>>>> + if (!result)
>>>>> + return false;
>>>>> +
>>>>> + result->data = malloc(length);
>>>>> + if (!result->data) {
>>>>> + free(result);
>>>>> + return false;
>>>>> + }
>>>>> +
>>>>> + result->handle = handle;
>>>>> + result->length = length;
>>>>> + memcpy(result->data, data, length);
>>>>> +
>>>>> + if (op->result_head) {
>>>>> + op->result_tail->next = result;
>>>>> + op->result_tail = result;
>>>>> + } else {
>>>>> + op->result_head = op->result_tail = result;
>>>>> + }
>>>>> +
>>>>> + return true;
>>>>> +}
>>>>> +
>>>>> +static void destroy_read_by_uuid_result(void *data)
>>>>> +{
>>>>> + struct read_by_uuid_res *result = data;
>>>>> +
>>>>> + free(result->data);
>>>>> + free(result);
>>>>> +}
>>>>> +
>>>>> +static struct read_by_uuid_op *read_by_uuid_op_ref(struct read_by_uuid_op *op)
>>>>> +{
>>>>> + __sync_fetch_and_add(&op->ref_count, 1);
>>>>> +
>>>>> + return op;
>>>>> +}
>>>>> +
>>>>> +static void read_by_uuid_op_unref(void *data)
>>>>> +{
>>>>> + struct read_by_uuid_res *next, *temp;
>>>>> + struct read_by_uuid_op *op = data;
>>>>> +
>>>>> + if (__sync_sub_and_fetch(&op->ref_count, 1))
>>>>> + return;
>>>>> +
>>>>> + if (op->destroy)
>>>>> + op->destroy(op->user_data);
>>>>> +
>>>>> + for (temp = op->result_head; temp; temp = next) {
>>>>> + next = temp->next;
>>>>> + destroy_read_by_uuid_result(temp);
>>>>> + }
>>>>> +
>>>>> + free(op);
>>>>> +}
>>>>> +
>>>>> +static void read_by_uuid_cb(uint8_t opcode, const void *pdu,
>>>>> + uint16_t length, void *user_data)
>>>>> +{
>>>>> + struct read_by_uuid_op *op = user_data;
>>>>> + size_t data_length;
>>>>> + uint8_t att_ecode;
>>>>> + uint16_t offset, last_handle;
>>>>> + const uint8_t *data;
>>>>> + bool success;
>>>>> +
>>>>> + if (opcode == BT_ATT_OP_ERROR_RSP) {
>>>>> + att_ecode = process_error(pdu, length);
>>>>> + if (att_ecode == BT_ATT_ERROR_ATTRIBUTE_NOT_FOUND)
>>>>> + success = true;
>>>>> + else
>>>>> + success = false;
>>>>> +
>>>>> + goto done;
>>>>> + }
>>>>> +
>>>>> + if (opcode != BT_ATT_OP_READ_BY_TYPE_RSP || (!pdu && length)) {
>>>>> + success = false;
>>>>> + att_ecode = 0;
>>>>> + goto done;
>>>>> + }
>>>>> +
>>>>> + data_length = ((const uint8_t *) pdu)[0];
>>>>> + if ((length - 1) % data_length) {
>>>>> + success = false;
>>>>> + att_ecode = 0;
>>>>> + goto done;
>>>>> + }
>>>>> +
>>>>> + for (offset = 1; offset < length; offset += data_length) {
>>>>> + data = pdu + offset;
>>>>> + if (!append_read_by_uuid_result(op, get_le16(data),
>>>>> + data_length - 2, data + 2)) {
>>>>> + success = false;
>>>>> + att_ecode = 0;
>>>>> + goto done;
>>>>> + }
>>>>> + }
>>>>> +
>>>>> + last_handle = get_le16(pdu + length - data_length);
>>>>> + if (last_handle < op->end_handle) {
>>>>> + uint8_t pdu[20];
>>>>> +
>>>>> + put_le16(last_handle + 1, pdu);
>>>>> + put_le16(op->end_handle, pdu + 2);
>>>>> +
>>>>> + if (is_bluetooth_uuid(op->uuid)) {
>>>>> + put_le16((op->uuid[2] << 8) + op->uuid[3], pdu + 4);
>>>>> + /*
>>>>> + * 2 octets - start handle
>>>>> + * 2 octets - end handle
>>>>> + * 2 octets - 16-bit uuid
>>>>> + */
>>>>> + length = 6;
>>>>> + } else {
>>>>> + bswap_128(&op->uuid, pdu + 4);
>>>>> + /*
>>>>> + * 2 octets - start handle
>>>>> + * 2 octets - end handle
>>>>> + * 16 octets - 128-bit uuid
>>>>> + */
>>>>> + length = 20;
>>>>> + }
>>>>> +
>>>>> + if (!bt_att_send(op->client->att, BT_ATT_OP_READ_BY_TYPE_REQ,
>>>>> + pdu, length, read_by_uuid_cb,
>>>>> + read_by_uuid_op_ref(op),
>>>>> + read_by_uuid_op_unref)) {
>>>>> + read_by_uuid_op_unref(op);
>>>>> + success = false;
>>>>> + att_ecode = 0;
>>>>> + goto done;
>>>>> + }
>>>>> +
>>>>> + return;
>>>>> + }
>>>>> +
>>>>> + success = true;
>>>>> + att_ecode = 0;
>>>>> +
>>>>> +done:
>>>>> + if (op->callback)
>>>>> + op->callback(success, att_ecode, op->result_head,
>>>>> + op->user_data);
>>>>> +}
>>>>> +
>>>>> +bool bt_gatt_client_read_by_uuid(struct bt_gatt_client *client,
>>>>> + uint16_t start_handle, uint16_t end_handle,
>>>>> + const uint8_t uuid[BT_GATT_UUID_SIZE],
>>>>> + bt_gatt_client_read_by_uuid_callback_t callback,
>>>>> + void *user_data,
>>>>> + bt_gatt_client_destroy_func_t destroy)
>>>>> +{
>>>>> + struct read_by_uuid_op *op;
>>>>> + uint16_t length;
>>>>> + uint8_t pdu[20];
>>>>> +
>>>>> + if (!client)
>>>>> + return false;
>>>>> +
>>>>> + if (start_handle > end_handle || start_handle == 0x0000)
>>>>> + return false;
>>>>> +
>>>>> + op = new0(struct read_by_uuid_op, 1);
>>>>> + if (!op)
>>>>> + return false;
>>>>> +
>>>>> + op->client = client;
>>>>> + op->start_handle = start_handle;
>>>>> + op->end_handle = end_handle;
>>>>> + op->destroy = destroy;
>>>>> + op->callback = callback;
>>>>> + op->user_data = user_data;
>>>>> + memcpy(&op->uuid, uuid, 16);
>>>>> +
>>>>> + /* Convert to 16-bit if it is Bluetooth UUID */
>>>>> + if (is_bluetooth_uuid(uuid)) {
>>>>> + put_le16((uuid[2] << 8) + uuid[3], pdu + 4);
>>>>> + /*
>>>>> + * 2 octets - start handle
>>>>> + * 2 octets - end handle
>>>>> + * 2 octets - 16-bit uuid
>>>>> + */
>>>>> + length = 6;
>>>>> + } else {
>>>>> + bswap_128(uuid, pdu + 4);
>>>>> + /*
>>>>> + * 2 octets - start handle
>>>>> + * 2 octets - end handle
>>>>> + * 16 octets - 128-bit uuid
>>>>> + */
>>>>> + length = 20;
>>>>> + }
>>>>> +
>>>>> + put_le16(start_handle, pdu);
>>>>> + put_le16(end_handle, pdu + 2);
>>>>> +
>>>>> + if (!bt_att_send(client->att, BT_ATT_OP_READ_BY_TYPE_REQ, pdu,
>>>>> + length, read_by_uuid_cb,
>>>>> + read_by_uuid_op_ref(op),
>>>>> + read_by_uuid_op_unref)) {
>>>>> + free(op);
>>>>> + return false;
>>>>> + }
>>>>> +
>>>>> + return true;
>>>>> +}
>>>>> +
>>>>> bool bt_gatt_client_write_without_response(struct bt_gatt_client *client,
>>>>> uint16_t value_handle,
>>>>> bool signed_write,
>>>>> diff --git a/src/shared/gatt-client.h b/src/shared/gatt-client.h
>>>>> index adccfc5..921ed75 100644
>>>>> --- a/src/shared/gatt-client.h
>>>>> +++ b/src/shared/gatt-client.h
>>>>> @@ -145,6 +145,24 @@ bool bt_gatt_client_read_long_value(struct bt_gatt_client *client,
>>>>> void *user_data,
>>>>> bt_gatt_client_destroy_func_t destroy);
>>>>>
>>>>> +struct read_by_uuid_res;
>>>>> +
>>>>> +struct read_by_uuid_res *read_by_uuid_res_next(struct read_by_uuid_res *result);
>>>>> +bool read_by_uuid_res_get(struct read_by_uuid_res *result, uint16_t *handle,
>>>>> + uint8_t *length, uint8_t **data);
>>>>> +
>>>>> +typedef void (*bt_gatt_client_read_by_uuid_callback_t)(bool success,
>>>>> + uint8_t att_ecode,
>>>>> + struct read_by_uuid_res *result,
>>>>> + void *user_data);
>>>>> +
>>>>> +bool bt_gatt_client_read_by_uuid(struct bt_gatt_client *client,
>>>>> + uint16_t start_handle, uint16_t end_handle,
>>>>> + const uint8_t uuid[BT_GATT_UUID_SIZE],
>>>>> + bt_gatt_client_read_by_uuid_callback_t callback,
>>>>> + void *user_data,
>>>>> + bt_gatt_client_destroy_func_t destroy);
>>>>
>>>> Isn't this essentially duplicating bt_gatt_service_iter_next_by_uuid?
>>>> I mean we should be reading everything already but this doesn't seems
>>>> to using the cache and in case it is just to fulfill a test perhaps it
>>>> is better to do it in gatt-helpers so we keep bt_gatt_client API
>>>> clean.
>>>
>>> It is functionality of GATT client described in chapter 4.8.2 "Read
>>> Using Characteristic UUID".
>>> Difference is that client can read attributes by passing UUID, and
>>> results can contain
>>> different valu lengths. And client interprets results instead of gatt-helpers.
>>> I implemented it here because all read/write operations on
>>> characteristics and descriptors
>>> are exposed in bt_gatt_client, and all discovery stuff is implemented
>>> in gatt_helpers. But if
>>> you don't agree I can change it.
>>
>> I see, it does actually end up reading, perhaps it is a good idea to
>> keep it here then. In the other hand this API seems to be going in the
>> same direction that gatt-db had with access by handles, perhaps we
>> should do an API facelift to access by attribute such as we did with
>> gatt-db, also the iterator could be replaced with queues which I guess
>> is not that different in the end.
>>
>
> The reason we have the iterators and not queues is because Marcel
> wanted to keep shared/queue as an internal utility of shared code
> (although shared/gatt-db exposes it to upper layers). In this case
> performing the read/write operations by handle isn't bad since the
> code simply constructs the request and sends it out and doesn't need
> to do an internal lookup for it.
>
> I commented on Marcin's new patch set that this code should go to
> gatt-helpers. I don't think it makes sense to put it in gatt-client,
> especially since the characteristic and include declaration discovery
Include service discovery can't be based on that API, because it
performs read_by_type
and read requests during discovery. It can be shared by characteristic
discovery only.
Additionally in characteristic discovery gatt-client interprets
results and cancel if length of
response is not valid. Also, you will be able to use include service
iterator and characteristic iterators
to read results of read-by-uuid (because it checks type of response
and length). I don't see benefit
having this in one place.
> procedures are already based on Read By Type and we can create a
> cleaner API by having this in gatt-helpers and basing the char/incl
> discovery functions on that instead.
>
>>>>
>>>>> bool bt_gatt_client_write_without_response(struct bt_gatt_client *client,
>>>>> uint16_t value_handle,
>>>>> bool signed_write,
>>>>> --
>>>>> 1.9.3
>>>>>
>>>>> --
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>>>>> the body of a message to majordomo@xxxxxxxxxxxxxxx
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>>>>
>>>>
>>>>
>>>> --
>>>> Luiz Augusto von Dentz
>>>
>>> BR
>>> Marcin
>>
>>
>>
>> --
>> Luiz Augusto von Dentz
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
>> the body of a message to majordomo@xxxxxxxxxxxxxxx
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> Cheers,
> Arman
BR
Marcin
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