From: Szymon Janc <szymon.janc@codecoup.pl>
To: Andrzej Kaczmarek <andrzej.kaczmarek@codecoup.pl>
Cc: linux-bluetooth@vger.kernel.org
Subject: Re: [PATCH v2] shared/gatt-client: Make read_long_value more robust
Date: Fri, 05 Feb 2016 11:18:14 +0100 [thread overview]
Message-ID: <2144527.11Fk0xgfcf@ix> (raw)
In-Reply-To: <1454307857-5337-1-git-send-email-andrzej.kaczmarek@codecoup.pl>
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
prev parent reply other threads:[~2016-02-05 10:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-01 6:24 [PATCH v2] shared/gatt-client: Make read_long_value more robust Andrzej Kaczmarek
2016-02-05 10:18 ` Szymon Janc [this message]
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