The shared/gatt-client functions for initiating read/write procedures
currently have no way to cancel them. The functions simple return a
boolean result to indicate success/failure. This patch fixes this by
returning a request id from these methods and adds the bt_gatt_cancel_*
functions to cancel a request with one of these ids.
bt_gatt_client internally manages its own set of request ids and maps
them to the underlying ATT request id returned by bt_att_send to
correctly cancel GATT procedures that span across multiple ATT protocol
PDUs.
---
src/shared/gatt-client.c | 298 +++++++++++++++++++++++++++++++++++++----------
src/shared/gatt-client.h | 14 ++-
2 files changed, 244 insertions(+), 68 deletions(-)
diff --git a/src/shared/gatt-client.c b/src/shared/gatt-client.c
index 10dfcbb..362fc32 100644
--- a/src/shared/gatt-client.c
+++ b/src/shared/gatt-client.c
@@ -65,7 +65,8 @@ struct bt_gatt_client {
bool in_init;
bool ready;
- /* Queue of long write requests. An error during "prepare write"
+ /*
+ * Queue of long write requests. An error during "prepare write"
* requests can result in a cancel through "execute write". To prevent
* cancelation of prepared writes to the wrong attribute and multiple
* requests to the same attribute that may result in a corrupted final
@@ -80,15 +81,75 @@ struct bt_gatt_client {
int next_reg_id;
unsigned int disc_id, notify_id, ind_id;
- /* Handles of the GATT Service and the Service Changed characteristic
+ /*
+ * Handles of the GATT Service and the Service Changed characteristic
* value handle. These will have the value 0 if they are not present on
* the remote peripheral.
*/
unsigned int svc_chngd_ind_id;
struct queue *svc_chngd_queue; /* Queued service changed events */
bool in_svc_chngd;
+
+ /*
+ * List of pending read/write operations. For operations that span
+ * across multiple PDUs, this list provides a mapping from an operation
+ * id to an ATT request id.
+ */
+ struct queue *pending_requests;
+ unsigned int next_request_id;
+};
+
+struct request {
+ struct bt_gatt_client *client;
+ bool removed;
+ int ref_count;
+ unsigned int id;
+ unsigned int att_id;
+ void *data;
+ void (*destroy)(void *);
};
+static struct request *request_ref(struct request *req)
+{
+ __sync_fetch_and_add(&req->ref_count, 1);
+
+ return req;
+}
+
+static struct request *request_create(struct bt_gatt_client *client)
+{
+ struct request *req;
+
+ req = new0(struct request, 1);
+ if (!req)
+ return NULL;
+
+ if (client->next_request_id < 1)
+ client->next_request_id = 1;
+
+ queue_push_tail(client->pending_requests, req);
+ req->client = client;
+ req->id = client->next_request_id++;
+
+ return request_ref(req);
+}
+
+static void request_unref(void *data)
+{
+ struct request *req = data;
+
+ if (__sync_sub_and_fetch(&req->ref_count, 1))
+ return;
+
+ if (req->destroy)
+ req->destroy(req->data);
+
+ if (!req->removed)
+ queue_remove(req->client->pending_requests, req);
+
+ free(req);
+}
+
struct notify_chrc {
uint16_t value_handle;
uint16_t ccc_handle;
@@ -1416,6 +1477,8 @@ static void long_write_op_unref(void *data);
static void bt_gatt_client_free(struct bt_gatt_client *client)
{
+ bt_gatt_client_cancel_all(client);
+
if (client->ready_destroy)
client->ready_destroy(client->ready_data);
@@ -1435,6 +1498,7 @@ static void bt_gatt_client_free(struct bt_gatt_client *client)
queue_destroy(client->long_write_queue, long_write_op_unref);
queue_destroy(client->notify_list, notify_data_unref);
queue_destroy(client->notify_chrcs, notify_chrc_free);
+ queue_destroy(client->pending_requests, request_unref);
free(client);
}
@@ -1490,6 +1554,10 @@ struct bt_gatt_client *bt_gatt_client_new(struct gatt_db *db,
if (!client->notify_chrcs)
goto fail;
+ client->pending_requests = queue_new();
+ if (!client->pending_requests)
+ goto fail;
+
client->notify_id = bt_att_register(att, BT_ATT_OP_HANDLE_VAL_NOT,
notify_cb, client, NULL);
if (!client->notify_id)
@@ -1600,6 +1668,49 @@ uint16_t bt_gatt_client_get_mtu(struct bt_gatt_client *client)
return bt_att_get_mtu(client->att);
}
+static bool match_req_id(const void *a, const void *b)
+{
+ const struct request *req = a;
+ unsigned int id = PTR_TO_UINT(b);
+
+ return req->id == id;
+}
+
+bool bt_gatt_client_cancel(struct bt_gatt_client *client, unsigned int id)
+{
+ struct request *req;
+
+ if (!client || !id || !client->att)
+ return false;
+
+ req = queue_remove_if(client->pending_requests, match_req_id,
+ UINT_TO_PTR(id));
+ if (!req)
+ return false;
+
+ req->removed = true;
+
+ return bt_att_cancel(client->att, req->att_id);
+}
+
+static void cancel_request(void *data)
+{
+ struct request *req = data;
+
+ req->removed = true;
+ bt_att_cancel(req->client->att, req->att_id);
+}
+
+bool bt_gatt_client_cancel_all(struct bt_gatt_client *client)
+{
+ if (!client || !client->att)
+ return false;
+
+ queue_remove_all(client->pending_requests, NULL, NULL, cancel_request);
+
+ return true;
+}
+
struct read_op {
bt_gatt_client_read_callback_t callback;
void *user_data;
@@ -1619,7 +1730,8 @@ static void destroy_read_op(void *data)
static void read_cb(uint8_t opcode, const void *pdu, uint16_t length,
void *user_data)
{
- struct read_op *op = user_data;
+ struct request *req = user_data;
+ struct read_op *op = req->data;
bool success;
uint8_t att_ecode = 0;
const uint8_t *value = NULL;
@@ -1646,42 +1758,56 @@ done:
op->callback(success, att_ecode, value, length, op->user_data);
}
-bool bt_gatt_client_read_value(struct bt_gatt_client *client,
+unsigned int bt_gatt_client_read_value(struct bt_gatt_client *client,
uint16_t value_handle,
bt_gatt_client_read_callback_t callback,
void *user_data,
bt_gatt_client_destroy_func_t destroy)
{
+ struct request *req;
struct read_op *op;
uint8_t pdu[2];
if (!client)
- return false;
+ return 0;
op = new0(struct read_op, 1);
if (!op)
- return false;
+ return 0;
+
+ req = request_create(client);
+ if (!req) {
+ free(op);
+ return 0;
+ }
op->callback = callback;
op->user_data = user_data;
op->destroy = destroy;
+ req->data = op;
+ req->destroy = destroy_read_op;
+
put_le16(value_handle, pdu);
- if (!bt_att_send(client->att, BT_ATT_OP_READ_REQ, pdu, sizeof(pdu),
- read_cb, op,
- destroy_read_op)) {
- free(op);
- return false;
+ req->att_id = bt_att_send(client->att, BT_ATT_OP_READ_REQ,
+ pdu, sizeof(pdu),
+ read_cb, req,
+ request_unref);
+ if (!req->att_id) {
+ op->destroy = NULL;
+ request_unref(req);
+ return 0;
}
- return true;
+ return req->id;
}
static void read_multiple_cb(uint8_t opcode, const void *pdu, uint16_t length,
void *user_data)
{
- struct read_op *op = user_data;
+ struct request *req = user_data;
+ struct read_op *op = req->data;
uint8_t att_ecode;
bool success;
@@ -1704,43 +1830,57 @@ static void read_multiple_cb(uint8_t opcode, const void *pdu, uint16_t length,
op->callback(success, att_ecode, pdu, length, op->user_data);
}
-bool bt_gatt_client_read_multiple(struct bt_gatt_client *client,
+unsigned int bt_gatt_client_read_multiple(struct bt_gatt_client *client,
uint16_t *handles, uint8_t num_handles,
bt_gatt_client_read_callback_t callback,
void *user_data,
bt_gatt_client_destroy_func_t destroy)
{
uint8_t pdu[num_handles * 2];
+ struct request *req;
struct read_op *op;
int i;
if (!client)
- return false;
+ return 0;
if (num_handles < 2)
- return false;
+ return 0;
if (num_handles * 2 > bt_att_get_mtu(client->att) - 1)
- return false;
+ return 0;
op = new0(struct read_op, 1);
if (!op)
- return false;
+ return 0;
+
+ req = request_create(client);
+ if (!client) {
+ free(op);
+ return 0;
+ }
op->callback = callback;
op->user_data = user_data;
op->destroy = destroy;
+ req->data = op;
+ req->destroy = destroy_read_op;
+
for (i = 0; i < num_handles; i++)
put_le16(handles[i], pdu + (2 * i));
- if (!bt_att_send(client->att, BT_ATT_OP_READ_MULT_REQ, pdu, sizeof(pdu),
- read_multiple_cb, op, destroy_read_op)) {
- free(op);
- return false;
+ req->att_id = bt_att_send(client->att, BT_ATT_OP_READ_MULT_REQ,
+ pdu, sizeof(pdu),
+ read_multiple_cb, req,
+ request_unref);
+ if (!req->att_id) {
+ op->destroy = NULL;
+ request_unref(req);
+ return 0;
}
- return true;
+ return req->id;
}
struct read_long_op {
@@ -1791,20 +1931,10 @@ static void destroy_blob(void *data)
free(blob);
}
-static struct read_long_op *read_long_op_ref(struct read_long_op *op)
-{
- __sync_fetch_and_add(&op->ref_count, 1);
-
- return op;
-}
-
-static void read_long_op_unref(void *data)
+static void destroy_read_long_op(void *data)
{
struct read_long_op *op = data;
- if (__sync_sub_and_fetch(&op->ref_count, 1))
- return;
-
if (op->destroy)
op->destroy(op->user_data);
@@ -1853,7 +1983,8 @@ done:
static void read_long_cb(uint8_t opcode, const void *pdu,
uint16_t length, void *user_data)
{
- struct read_long_op *op = user_data;
+ struct request *req = user_data;
+ struct read_long_op *op = req->data;
struct blob *blob;
bool success;
uint8_t att_ecode = 0;
@@ -1889,14 +2020,16 @@ static void read_long_cb(uint8_t opcode, const void *pdu,
put_le16(op->value_handle, pdu);
put_le16(op->offset, pdu + 2);
- if (bt_att_send(op->client->att, BT_ATT_OP_READ_BLOB_REQ,
+ req->att_id = bt_att_send(op->client->att,
+ BT_ATT_OP_READ_BLOB_REQ,
pdu, sizeof(pdu),
read_long_cb,
- read_long_op_ref(op),
- read_long_op_unref))
+ request_ref(req),
+ request_unref);
+ if (req->att_id)
return;
- read_long_op_unref(op);
+ request_unref(req);
success = false;
goto done;
}
@@ -1908,26 +2041,34 @@ done:
complete_read_long_op(op, success, att_ecode);
}
-bool bt_gatt_client_read_long_value(struct bt_gatt_client *client,
+unsigned int bt_gatt_client_read_long_value(struct bt_gatt_client *client,
uint16_t value_handle, uint16_t offset,
bt_gatt_client_read_callback_t callback,
void *user_data,
bt_gatt_client_destroy_func_t destroy)
{
+ struct request *req;
struct read_long_op *op;
uint8_t pdu[4];
if (!client)
- return false;
+ return 0;
op = new0(struct read_long_op, 1);
if (!op)
- return false;
+ return 0;
op->blobs = queue_new();
if (!op->blobs) {
free(op);
- return false;
+ return 0;
+ }
+
+ req = request_create(client);
+ if (!req) {
+ queue_destroy(op->blobs, free);
+ free(op);
+ return 0;
}
op->client = client;
@@ -1938,26 +2079,32 @@ bool bt_gatt_client_read_long_value(struct bt_gatt_client *client,
op->user_data = user_data;
op->destroy = destroy;
+ req->data = op;
+ req->destroy = destroy_read_long_op;
+
put_le16(value_handle, pdu);
put_le16(offset, pdu + 2);
- if (!bt_att_send(client->att, BT_ATT_OP_READ_BLOB_REQ, pdu, sizeof(pdu),
- read_long_cb,
- read_long_op_ref(op),
- read_long_op_unref)) {
- queue_destroy(op->blobs, free);
- free(op);
- return false;
+ 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);
+ return 0;
}
- return true;
+ return req->id;
}
-bool bt_gatt_client_write_without_response(struct bt_gatt_client *client,
+unsigned int bt_gatt_client_write_without_response(
+ struct bt_gatt_client *client,
uint16_t value_handle,
bool signed_write,
const uint8_t *value, uint16_t length) {
uint8_t pdu[2 + length];
+ struct request *req;
if (!client)
return 0;
@@ -1966,11 +2113,22 @@ bool bt_gatt_client_write_without_response(struct bt_gatt_client *client,
if (signed_write)
return 0;
+ req = request_create(client);
+ if (!req)
+ return 0;
+
put_le16(value_handle, pdu);
memcpy(pdu + 2, value, length);
- return bt_att_send(client->att, BT_ATT_OP_WRITE_CMD, pdu, sizeof(pdu),
+ req->att_id = bt_att_send(client->att, BT_ATT_OP_WRITE_CMD,
+ pdu, sizeof(pdu),
NULL, NULL, NULL);
+ if (!req->att_id) {
+ request_unref(req);
+ return 0;
+ }
+
+ return req->id;
}
struct write_op {
@@ -1992,7 +2150,8 @@ static void destroy_write_op(void *data)
static void write_cb(uint8_t opcode, const void *pdu, uint16_t length,
void *user_data)
{
- struct write_op *op = user_data;
+ struct request *req = user_data;
+ struct write_op *op = req->data;
bool success = true;
uint8_t att_ecode = 0;
@@ -2010,38 +2169,51 @@ done:
op->callback(success, att_ecode, op->user_data);
}
-bool bt_gatt_client_write_value(struct bt_gatt_client *client,
+unsigned int bt_gatt_client_write_value(struct bt_gatt_client *client,
uint16_t value_handle,
const uint8_t *value, uint16_t length,
bt_gatt_client_callback_t callback,
void *user_data,
bt_gatt_client_destroy_func_t destroy)
{
+ struct request *req;
struct write_op *op;
uint8_t pdu[2 + length];
if (!client)
- return false;
+ return 0;
op = new0(struct write_op, 1);
if (!op)
- return false;
+ return 0;
+
+ req = request_create(client);
+ if (!req) {
+ free(op);
+ return 0;
+ }
op->callback = callback;
op->user_data = user_data;
op->destroy = destroy;
+ req->data = op;
+ req->destroy = destroy_write_op;
+
put_le16(value_handle, pdu);
memcpy(pdu + 2, value, length);
- if (!bt_att_send(client->att, BT_ATT_OP_WRITE_REQ, pdu, sizeof(pdu),
- write_cb, op,
- destroy_write_op)) {
- free(op);
- return false;
+ req->att_id = bt_att_send(client->att, BT_ATT_OP_WRITE_REQ,
+ pdu, sizeof(pdu),
+ write_cb, req,
+ request_unref);
+ if (!req->att_id) {
+ op->destroy = NULL;
+ request_unref(req);
+ return 0;
}
- return true;
+ return req->id;
}
struct long_write_op {
diff --git a/src/shared/gatt-client.h b/src/shared/gatt-client.h
index 42eeaec..74d781c 100644
--- a/src/shared/gatt-client.h
+++ b/src/shared/gatt-client.h
@@ -72,27 +72,31 @@ bool bt_gatt_client_set_debug(struct bt_gatt_client *client,
uint16_t bt_gatt_client_get_mtu(struct bt_gatt_client *client);
-bool bt_gatt_client_read_value(struct bt_gatt_client *client,
+bool bt_gatt_client_cancel(struct bt_gatt_client *client, unsigned int id);
+bool bt_gatt_client_cancel_all(struct bt_gatt_client *client);
+
+unsigned int bt_gatt_client_read_value(struct bt_gatt_client *client,
uint16_t value_handle,
bt_gatt_client_read_callback_t callback,
void *user_data,
bt_gatt_client_destroy_func_t destroy);
-bool bt_gatt_client_read_long_value(struct bt_gatt_client *client,
+unsigned int bt_gatt_client_read_long_value(struct bt_gatt_client *client,
uint16_t value_handle, uint16_t offset,
bt_gatt_client_read_callback_t callback,
void *user_data,
bt_gatt_client_destroy_func_t destroy);
-bool bt_gatt_client_read_multiple(struct bt_gatt_client *client,
+unsigned int bt_gatt_client_read_multiple(struct bt_gatt_client *client,
uint16_t *handles, uint8_t num_handles,
bt_gatt_client_read_callback_t callback,
void *user_data,
bt_gatt_client_destroy_func_t destroy);
-bool bt_gatt_client_write_without_response(struct bt_gatt_client *client,
+unsigned int bt_gatt_client_write_without_response(
+ struct bt_gatt_client *client,
uint16_t value_handle,
bool signed_write,
const uint8_t *value, uint16_t length);
-bool bt_gatt_client_write_value(struct bt_gatt_client *client,
+unsigned int bt_gatt_client_write_value(struct bt_gatt_client *client,
uint16_t value_handle,
const uint8_t *value, uint16_t length,
bt_gatt_client_callback_t callback,
--
2.2.0.rc0.207.ga3a616c
--
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