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
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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>>>
>>>
>>>
>>> --
>>> Luiz Augusto von Dentz
>>
>> BR
>> Marcin
>
>
>
> --
> Luiz Augusto von Dentz
> --
> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
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Cheers,
Arman
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