Hi Arman,
On Tue, Oct 7, 2014 at 12:01 AM, Arman Uguray <armansito@xxxxxxxxxxxx> wrote:
> This patch adds handling for the Read By Group Type request.
> ---
> src/shared/gatt-server.c | 170 ++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 169 insertions(+), 1 deletion(-)
>
> diff --git a/src/shared/gatt-server.c b/src/shared/gatt-server.c
> index c7b0873..3ea8c59 100644
> --- a/src/shared/gatt-server.c
> +++ b/src/shared/gatt-server.c
> @@ -45,6 +45,7 @@ struct bt_gatt_server {
> uint16_t mtu;
>
> unsigned int mtu_id;
> + unsigned int read_by_grp_type_id;
>
> bt_gatt_server_debug_func_t debug_callback;
> bt_gatt_server_destroy_func_t debug_destroy;
> @@ -54,6 +55,7 @@ struct bt_gatt_server {
> static void gatt_server_unregister_handlers(struct bt_gatt_server *server)
> {
> bt_att_unregister(server->att, server->mtu_id);
> + bt_att_unregister(server->att, server->read_by_grp_type_id);
> }
>
> static void gatt_server_cleanup(struct bt_gatt_server *server)
> @@ -71,6 +73,157 @@ static void encode_error_rsp(uint8_t opcode, uint16_t handle, uint8_t ecode,
> put_le16(handle, pdu + 1);
> }
>
> +static bool get_uuid_le(const uint8_t *uuid, size_t len, bt_uuid_t *out_uuid)
> +{
> + uint128_t u128;
> +
> + switch (len) {
> + case 2:
> + bt_uuid16_create(out_uuid, get_le16(uuid));
> + return true;
> + case 16:
> + bswap_128(uuid, &u128.data);
> + bt_uuid128_create(out_uuid, u128);
> + return true;
> + default:
> + return false;
> + }
> +
> + return false;
> +}
> +
> +static void read_by_grp_type_cb(uint8_t opcode, const void *pdu,
> + uint16_t length, void *user_data)
> +{
> + struct bt_gatt_server *server = user_data;
> + uint16_t start, end;
> + bt_uuid_t type;
> + bt_uuid_t prim, snd;
> + uint16_t mtu = bt_att_get_mtu(server->att);
> + uint8_t rsp_pdu[mtu];
> + uint16_t rsp_len;
> + uint8_t rsp_opcode;
> + uint8_t ecode = 0;
> + uint16_t ehandle = 0;
> + struct queue *q = NULL;
> + int iter = 0;
> + uint8_t data_val_len;
> +
> + if (length != 6 && length != 20) {
> + ecode = BT_ATT_ERROR_INVALID_PDU;
> + goto error;
> + }
> +
> + q = queue_new();
> + if (!q) {
> + ecode = BT_ATT_ERROR_INSUFFICIENT_RESOURCES;
> + goto error;
> + }
> +
> + start = get_le16(pdu);
> + end = get_le16(pdu + 2);
> + get_uuid_le(pdu + 4, length - 4, &type);
> +
> + util_debug(server->debug_callback, server->debug_data,
> + "Read By Grp Type - start: 0x%04x end: 0x%04x",
> + start, end);
> +
> + if (!start || !end) {
> + ecode = BT_ATT_ERROR_INVALID_HANDLE;
> + goto error;
> + }
> +
> + ehandle = start;
> +
> + if (start > end) {
> + ecode = BT_ATT_ERROR_INVALID_HANDLE;
> + goto error;
> + }
> +
> + /* GATT defines that only the <<Primary Service>> and
> + * <<Secondary Service>> group types can be used for the
> + * "Read By Group Type" request (Core v4.1, Vol 3, sec 2.5.3). Return an
> + * error if any other group type is given.
> + */
> + bt_uuid16_create(&prim, GATT_PRIM_SVC_UUID);
> + bt_uuid16_create(&snd, GATT_SND_SVC_UUID);
> + if (bt_uuid_cmp(&type, &prim) && bt_uuid_cmp(&type, &snd)) {
> + ecode = BT_ATT_ERROR_UNSUPPORTED_GROUP_TYPE;
> + goto error;
> + }
> +
> + gatt_db_read_by_group_type(server->db, start, end, type, q);
> +
> + if (queue_isempty(q)) {
> + ecode = BT_ATT_ERROR_ATTRIBUTE_NOT_FOUND;
> + goto error;
> + }
This function is quite long, perhaps using queue_foreach be better
than iterating inline since you destroy the queue at end but it would
be a problem if one of items fails to be encoded, the funny thing is
that it is possible to do the same with queue_find and return true to
interrupt in case of failure but it would be a obvious abuse of the
API so perhaps queue_foreach_func_t could have a return as well and in
case it return false we stop.
> + rsp_len = 0;
> + while (queue_peek_head(q)) {
> + uint16_t start_handle = PTR_TO_UINT(queue_pop_head(q));
> + uint16_t end_handle;
> + uint8_t *value = NULL;
> + int value_len = 0;
> +
> + /* TODO: Figure out how to check permissions based on security
> + * level on a bt_att, which sits on a generic io.
> + */
> +
> + if (!gatt_db_read(server->db, start_handle, 0, opcode, NULL,
> + &value, &value_len)) {
> + ecode = BT_ATT_ERROR_UNLIKELY;
> + goto error;
> + }
> +
> + if (value_len < 0) {
> + /* This should never happen for primary/secondary
> + * service declarations.
> + */
> + ecode = BT_ATT_ERROR_UNLIKELY;
> + goto error;
> + }
> +
> + /* Use the first attribute to determine the length of each
> + * attribute data unit. Stop the list when a different attribute
> + * value is seen.
> + */
> + if (iter == 0) {
> + data_val_len = value_len;
> + rsp_pdu[0] = data_val_len + 4;
> + iter++;
> + } else if (value_len != data_val_len)
> + break;
> +
> + /* Stop if this unit would surpass the MTU */
> + if (iter + data_val_len + 4 > mtu)
> + break;
> +
> + end_handle = gatt_db_get_end_handle(server->db, start_handle);
> +
> + put_le16(start_handle, rsp_pdu + iter);
> + put_le16(end_handle, rsp_pdu + iter + 2);
> + memcpy(rsp_pdu + iter + 4, value, value_len);
> +
> + iter += data_val_len + 4;
> + }
> +
> + rsp_opcode = BT_ATT_OP_READ_BY_GRP_TYPE_RSP;
> + rsp_len = iter;
> +
> + goto done;
> +
> +error:
> + rsp_opcode = BT_ATT_OP_ERROR_RSP;
> + rsp_len = 4;
> + encode_error_rsp(opcode, ehandle, ecode, rsp_pdu);
> +
> +done:
> + queue_destroy(q, NULL);
> + bt_att_send(server->att, rsp_opcode, rsp_pdu, rsp_len,
> + NULL, NULL, NULL);
> +}
> +
> static void exchange_mtu_cb(uint8_t opcode, const void *pdu,
> uint16_t length, void *user_data)
> {
> @@ -97,18 +250,33 @@ static void exchange_mtu_cb(uint8_t opcode, const void *pdu,
> /* Set MTU to be the minimum */
> server->mtu = final_mtu;
> bt_att_set_mtu(server->att, final_mtu);
> +
> + util_debug(server->debug_callback, server->debug_data,
> + "MTU exchange complete, with MTU: %u", final_mtu);
> }
>
> static bool gatt_server_register_att_handlers(struct bt_gatt_server *server)
> {
> - /* EXCHANGE MTU request */
> + /* Exchange MTU */
> server->mtu_id = bt_att_register(server->att, BT_ATT_OP_MTU_REQ,
> exchange_mtu_cb,
> server, NULL);
> if (!server->mtu_id)
> return false;
>
> + /* Read By Group Type */
> + server->read_by_grp_type_id = bt_att_register(server->att,
> + BT_ATT_OP_READ_BY_GRP_TYPE_REQ,
> + read_by_grp_type_cb,
> + server, NULL);
> + if (!server->read_by_grp_type_id)
> + goto fail;
> +
> return true;
> +
> +fail:
> + gatt_server_unregister_handlers(server);
> + return false;
> }
>
> struct bt_gatt_server *bt_gatt_server_new(struct gatt_db *db,
> --
> 2.1.0.rc2.206.gedb03e5
>
> --
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--
Luiz Augusto von Dentz
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