Hi Arman,
> This patch implements bt_gatt_discover_primary_services for the case when no
> UUID is provided.
> ---
> src/shared/gatt-helpers.c | 253 +++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 251 insertions(+), 2 deletions(-)
>
> diff --git a/src/shared/gatt-helpers.c b/src/shared/gatt-helpers.c
> index 96137bf..d427eaf 100644
> --- a/src/shared/gatt-helpers.c
> +++ b/src/shared/gatt-helpers.c
> @@ -36,6 +36,70 @@
> #define MIN(a, b) ((a) < (b) ? (a) : (b))
> #endif
>
> +struct bt_gatt_list {
> + struct bt_gatt_list *next;
> + void *data;
> +};
> +
> +struct list_ptrs {
> + struct bt_gatt_list *head;
> + struct bt_gatt_list *tail;
> +};
> +
> +struct bt_gatt_list *bt_gatt_list_get_next(struct bt_gatt_list *list)
> +{
> + return list->next;
> +}
> +
> +void *bt_gatt_list_get_data(struct bt_gatt_list *list)
> +{
> + return list->data;
> +}
> +
> +static inline bool list_isempty(struct list_ptrs *list)
> +{
> + return !list->head && !list->tail;
> +}
> +
> +static bool list_add(struct list_ptrs *list, void *data)
> +{
> + struct bt_gatt_list *item = new0(struct bt_gatt_list, 1);
> + if (!item)
> + return false;
> +
> + item->data = data;
> +
> + if (list_isempty(list)) {
> + list->head = list->tail = item;
> + return true;
> + }
> +
> + list->tail->next = item;
> + list->tail = item;
> +
> + return true;
> +}
> +
> +static void list_free(struct list_ptrs *list, bt_gatt_destroy_func_t destroy)
> +{
> + struct bt_gatt_list *l, *tmp;
> + l = list->head;
> +
> + while (l) {
> + if (destroy)
> + destroy(l->data);
> +
> + tmp = l->next;
> + free(l);
> + l = tmp;
> + }
> +}
> +
> +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 mtu_op {
> struct bt_att *att;
> uint16_t client_rx_mtu;
> @@ -122,14 +186,199 @@ bool bt_gatt_exchange_mtu(struct bt_att *att, uint16_t client_rx_mtu,
> return true;
> }
>
> +struct discovery_op {
> + struct bt_att *att;
> + int ref_count;
> + bt_uuid_t uuid;
> + struct list_ptrs results;
> + bt_gatt_discovery_callback_t callback;
> + void *user_data;
> + bt_gatt_destroy_func_t destroy;
> +};
> +
> +static struct discovery_op* discovery_op_ref(struct discovery_op *op)
> +{
> + __sync_fetch_and_add(&op->ref_count, 1);
> +
> + return op;
> +}
> +
> +static void discovery_op_unref(void *data)
> +{
> + struct discovery_op *op = data;
> +
> + if (__sync_sub_and_fetch(&op->ref_count, 1))
> + return;
> +
> + if (op->destroy)
> + op->destroy(op->user_data);
> +
> + list_free(&op->results, free);
> +
> + free(op);
> +}
> +
> +static void put_uuid_le(const bt_uuid_t *src, void *dst)
> +{
> + if (src->type == BT_UUID16)
> + put_le16(src->value.u16, dst);
> + else
> + bswap_128(&src->value.u128, dst);
> +}
> +
> +static bool convert_uuid_le(const uint8_t *src, size_t len, uint8_t dst[16])
> +{
> + if (len == 16) {
> + bswap_128(src, dst);
> + return true;
> + }
> +
> + if (len != 2)
> + return false;
> +
> + memcpy(dst, bt_base_uuid, sizeof(bt_base_uuid));
> + dst[2] = src[1];
> + dst[3] = src[0];
> +
> + return true;
> +}
> +
> +static void read_by_grp_type_cb(uint8_t opcode, const void *pdu,
> + uint16_t length, void *user_data)
> +{
> + struct discovery_op *op = user_data;
> + bool success;
> + uint8_t att_ecode = 0;
> + struct bt_gatt_list *results = NULL;
> + size_t data_length;
> + size_t list_length;
> + uint16_t last_end;
> + int i;
> +
> + if (opcode == BT_ATT_OP_ERROR_RSP) {
> + success = false;
> + att_ecode = process_error(pdu, length);
> +
> + if (att_ecode == BT_ATT_ERROR_ATTRIBUTE_NOT_FOUND &&
> + !list_isempty(&op->results))
> + goto success;
> +
> + goto done;
> + }
> +
> + /* PDU must contain at least the following (sans opcode):
> + * - Attr Data Length (1 octet)
> + * - Attr Data List (at least 6 octets):
> + * -- 2 octets: Attribute handle
> + * -- 2 octets: End group handle
> + * -- 2 or 16 octets: service UUID
> + */
> + if (opcode != BT_ATT_OP_READ_BY_GRP_TYPE_RSP || !pdu || length < 7) {
> + success = false;
> + goto done;
> + }
> +
> + data_length = ((uint8_t *) pdu)[0];
> + list_length = length - 1;
> +
> + if ((list_length % data_length) ||
> + (data_length != 6 && data_length != 20)) {
> + success = false;
> + goto done;
> + }
> +
> + for (i = 1; i < length; i += data_length) {
> + struct bt_gatt_service *service;
> +
> + service = new0(struct bt_gatt_service, 1);
> + if (!service) {
> + success = false;
> + goto done;
> + }
> +
> + service->start = get_le16(pdu + i);
> + last_end = get_le16(pdu + i + 2);
> + service->end = last_end;
> + convert_uuid_le(pdu + i + 4, data_length - 4, service->uuid);
> +
> + if (!list_add(&op->results, service)) {
> + success = false;
> + goto done;
> + }
> + }
> +
> + if (last_end != 0xffff) {
> + uint8_t pdu[6];
> +
> + put_le16(last_end + 1, pdu);
> + put_le16(0xffff, pdu + 2);
> + put_le16(GATT_PRIM_SVC_UUID, pdu + 4);
> +
> + if (bt_att_send(op->att, BT_ATT_OP_READ_BY_GRP_TYPE_REQ,
> + pdu, sizeof(pdu),
> + read_by_grp_type_cb,
> + discovery_op_ref(op),
> + discovery_op_unref))
> + return;
> +
> + discovery_op_unref(op);
> + success = false;
> + goto done;
I think we need to fix bt_att_send to return false when we got disconnected in between the individual commands. I did run some tests with the code here and if we receive a disconnect, we get stuck and the callback is never called. So when we have running longer procedures, we need to handle the cases where we loose the connection in the middle of it.
Regards
Marcel
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