Re: [PATCH v2] shared/gatt-client: Make read_long_value more robust

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Andrzej,

On Monday 01 February 2016 07:24:17 Andrzej Kaczmarek wrote:
> Using "Read Blob Request" on attributes shorter than ATT_MTU - 3 may
> return "Attribute Not Long" error on some values, but at the same time
> it's ok to read this attribute using "Read Request".
> 
> Since using "Read Blob Request" as first request when reading long
> characteristic value starting with offset 0 is optional, this patch
> changes read_long_value to start with "Read Request" whenever possible
> to remove need for caller to take care of such error.
> 
> Core v4.2, part F, section 1.3.4.4.5:
> If the attribute value has a fixed length that is less than or equal to
> (ATT_MTU - 3) octets in length, then an Error Response can be sent with
> the error code «Attribute Not Long».
> ---
>  src/shared/gatt-client.c | 36 ++++++++++++++++++----
>  unit/test-gatt.c         | 78
> ++++++++++++++++++++++++------------------------ 2 files changed, 69
> insertions(+), 45 deletions(-)
> 
> diff --git a/src/shared/gatt-client.c b/src/shared/gatt-client.c
> index 06ac763..5c95a62 100644
> --- a/src/shared/gatt-client.c
> +++ b/src/shared/gatt-client.c
> @@ -2156,7 +2156,9 @@ static void read_long_cb(uint8_t opcode, const void
> *pdu, goto done;
>  	}
> 
> -	if (opcode != BT_ATT_OP_READ_BLOB_RSP || (!pdu && length)) {
> +	if ((!op->offset && opcode != BT_ATT_OP_READ_RSP)
> +			|| (op->offset && opcode != BT_ATT_OP_READ_BLOB_RSP)
> +			|| (!pdu && length)) {
>  		success = false;
>  		goto done;
>  	}
> @@ -2209,7 +2211,9 @@ unsigned int bt_gatt_client_read_long_value(struct
> bt_gatt_client *client, {
>  	struct request *req;
>  	struct read_long_op *op;
> +	uint8_t att_op;
>  	uint8_t pdu[4];
> +	uint16_t pdu_len;
> 
>  	if (!client)
>  		return 0;
> @@ -2233,12 +2237,32 @@ unsigned int bt_gatt_client_read_long_value(struct
> bt_gatt_client *client, req->destroy = destroy_read_long_op;
> 
>  	put_le16(value_handle, pdu);
> -	put_le16(offset, pdu + 2);
> +	pdu_len = sizeof(value_handle);
> +
> +	/*
> +	 * Core v4.2, part F, section 1.3.4.4.5:
> +	 * If the attribute value has a fixed length that is less than or equal
> +	 * to (ATT_MTU - 3) octets in length, then an Error Response can be sent
> +	 * with the error code «Attribute Not Long».
> +	 *
> +	 * To remove need for caller to handle "Attribute Not Long" error when
> +	 * reading characteristics with short values, use Read Request for
> +	 * reading first part of characteristics value instead of Read Blob
> +	 * Request. Both are allowed in this case.
> +	 */
> +
> +	if (op->offset) {
> +		att_op = BT_ATT_OP_READ_BLOB_REQ;
> +		pdu_len += sizeof(op->offset);
> +
> +		put_le16(op->offset, pdu + 2);
> +	} else {
> +		att_op = BT_ATT_OP_READ_REQ;
> +	}
> +
> +	req->att_id = bt_att_send(client->att, att_op, pdu, pdu_len,
> +					read_long_cb, req, request_unref);
> 
> -	req->att_id = bt_att_send(client->att, BT_ATT_OP_READ_BLOB_REQ,
> -							pdu, sizeof(pdu),
> -							read_long_cb, req,
> -							request_unref);
>  	if (!req->att_id) {
>  		op->destroy = NULL;
>  		request_unref(req);
> diff --git a/unit/test-gatt.c b/unit/test-gatt.c
> index 326a32c..944bfba 100644
> --- a/unit/test-gatt.c
> +++ b/unit/test-gatt.c
> @@ -2892,14 +2892,14 @@ int main(int argc, char *argv[])
>  	define_test_client("/TP/GAR/CL/BV-04-C", test_client, service_db_1,
>  			&test_long_read_1,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x03, 0x00, 0x00, 0x00),
> -			raw_pdu(0x0d, 0x01, 0x02, 0x03));
> +			raw_pdu(0x0a, 0x03, 0x00),
> +			raw_pdu(0x0b, 0x01, 0x02, 0x03));
> 
>  	define_test_client("/TP/GAR/CL/BV-04-C/512B", test_client, service_db_1,
>  			&test_long_read_2,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x03, 0x00, 0x00, 0x00),
> -			raw_pdu(0x0d, 0xff, 0xff, 0xff, 0xff,
> +			raw_pdu(0x0a, 0x03, 0x00),
> +			raw_pdu(0x0b, 0xff, 0xff, 0xff, 0xff,
>  				0xff, 0xff, 0xff, 0xff, 0xff,
>  				0xff, 0xff, 0xff, 0xff, 0xff,
>  				0xff, 0xff, 0xff, 0xff, 0xff,
> @@ -3014,46 +3014,46 @@ int main(int argc, char *argv[])
>  	define_test_client("/TP/GAR/CL/BI-12-C", test_client, service_db_1,
>  			&test_long_read_3,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x03, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x03, 0x00, 0x02));
> +			raw_pdu(0x0a, 0x03, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x03, 0x00, 0x02));
> 
>  	define_test_client("/TP/GAR/CL/BI-13-C", test_client, service_db_1,
>  			&test_long_read_4,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x03, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x03, 0x00, 0x07));
> +			raw_pdu(0x0a, 0x03, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x03, 0x00, 0x07));
> 
>  	define_test_client("/TP/GAR/CL/BI-14-C", test_client, service_db_1,
>  			&test_long_read_5,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x00, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x00, 0x00, 0x01));
> +			raw_pdu(0x0a, 0x00, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x00, 0x00, 0x01));
> 
>  	define_test_client("/TP/GAR/CL/BI-15-C", test_client, service_db_1,
>  			&test_long_read_6,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x03, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x03, 0x00, 0x08));
> +			raw_pdu(0x0a, 0x03, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x03, 0x00, 0x08));
> 
>  	define_test_client("/TP/GAR/CL/BI-16-C", test_client, service_db_1,
>  			&test_long_read_7,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x03, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x03, 0x00, 0x05));
> +			raw_pdu(0x0a, 0x03, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x03, 0x00, 0x05));
> 
>  	define_test_client("/TP/GAR/CL/BI-16-C/auto", test_client, service_db_1,
>  			&test_long_read_1,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x03, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x03, 0x00, 0x05),
> -			raw_pdu(0x0c, 0x03, 0x00, 0x00, 0x00),
> +			raw_pdu(0x0a, 0x03, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x03, 0x00, 0x05),
> +			raw_pdu(0x0a, 0x03, 0x00),
>  			raw_pdu(0x0d, 0x01, 0x02, 0x03));
> 
>  	define_test_client("/TP/GAR/CL/BI-17-C", test_client, service_db_1,
>  			&test_long_read_8,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x03, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x03, 0x00, 0x0c));
> +			raw_pdu(0x0a, 0x03, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x03, 0x00, 0x0c));
> 
>  	define_test_client("/TP/GAR/CL/BI-18-C", test_client, service_db_1,
>  			&test_multiple_read_2,
> @@ -3299,14 +3299,14 @@ int main(int argc, char *argv[])
>  	define_test_client("/TP/GAR/CL/BV-07-C", test_client, service_db_1,
>  			&test_long_read_9,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x04, 0x00, 0x00, 0x00),
> -			raw_pdu(0x0d, 0x01, 0x02, 0x03));
> +			raw_pdu(0x0a, 0x04, 0x00),
> +			raw_pdu(0x0b, 0x01, 0x02, 0x03));
> 
>  	define_test_client("/TP/GAR/CL/BV-07-C/512B", test_client, service_db_1,
>  			&test_long_read_10,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x04, 0x00, 0x00, 0x00),
> -			raw_pdu(0x0d, 0xff, 0xff, 0xff, 0xff,
> +			raw_pdu(0x0a, 0x04, 0x00),
> +			raw_pdu(0x0b, 0xff, 0xff, 0xff, 0xff,
>  				0xff, 0xff, 0xff, 0xff, 0xff,
>  				0xff, 0xff, 0xff, 0xff, 0xff,
>  				0xff, 0xff, 0xff, 0xff, 0xff,
> @@ -3415,46 +3415,46 @@ int main(int argc, char *argv[])
>  	define_test_client("/TP/GAR/CL/BI-28-C", test_client, service_db_1,
>  			&test_long_read_11,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x04, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x04, 0x00, 0x02));
> +			raw_pdu(0x0a, 0x04, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x04, 0x00, 0x02));
> 
>  	define_test_client("/TP/GAR/CL/BI-29-C", test_client, service_db_1,
>  			&test_long_read_12,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x04, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x04, 0x00, 0x07));
> +			raw_pdu(0x0a, 0x04, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x04, 0x00, 0x07));
> 
>  	define_test_client("/TP/GAR/CL/BI-30-C", test_client, service_db_1,
>  			&test_long_read_5,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x00, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x00, 0x00, 0x01));
> +			raw_pdu(0x0a, 0x00, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x00, 0x00, 0x01));
> 
>  	define_test_client("/TP/GAR/CL/BI-31-C", test_client, service_db_1,
>  			&test_long_read_13,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x04, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x04, 0x00, 0x08));
> +			raw_pdu(0x0a, 0x04, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x04, 0x00, 0x08));
> 
>  	define_test_client("/TP/GAR/CL/BI-32-C", test_client, service_db_1,
>  			&test_long_read_14,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x04, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x04, 0x00, 0x05));
> +			raw_pdu(0x0a, 0x04, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x04, 0x00, 0x05));
> 
>  	define_test_client("/TP/GAR/CL/BI-32-C/auto", test_client, service_db_1,
>  			&test_long_read_9,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x04, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x04, 0x00, 0x05),
> -			raw_pdu(0x0c, 0x04, 0x00, 0x00, 0x00),
> -			raw_pdu(0x0d, 0x01, 0x02, 0x03));
> +			raw_pdu(0x0a, 0x04, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x04, 0x00, 0x05),
> +			raw_pdu(0x0a, 0x04, 0x00),
> +			raw_pdu(0x0b, 0x01, 0x02, 0x03));
> 
>  	define_test_client("/TP/GAR/CL/BI-33-C", test_client, service_db_1,
>  			&test_long_read_15,
>  			SERVICE_DATA_1_PDUS,
> -			raw_pdu(0x0c, 0x04, 0x00, 0x00, 0x00),
> -			raw_pdu(0x01, 0x0c, 0x04, 0x00, 0x0c));
> +			raw_pdu(0x0a, 0x04, 0x00),
> +			raw_pdu(0x01, 0x0a, 0x04, 0x00, 0x0c));
> 
>  	define_test_client("/TP/GAR/CL/BI-34-C", test_client, service_db_1,
>  			&test_read_12,

Patch applied, thanks.

-- 
pozdrawiam
Szymon Janc
--
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



[Index of Archives]     [Bluez Devel]     [Linux Wireless Networking]     [Linux Wireless Personal Area Networking]     [Linux ATH6KL]     [Linux USB Devel]     [Linux Media Drivers]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Big List of Linux Books]

  Powered by Linux