From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
The Read Multiple Variable Length Request is used to request that the
server read two or more values of a set of attributes that have a
variable or unknown value length and return their values in a
Read Multiple Variable Length Response.
---
src/shared/att-types.h | 2 +
src/shared/gatt-server.c | 112 +++++++++++++++++++++++++++------------
2 files changed, 80 insertions(+), 34 deletions(-)
diff --git a/src/shared/att-types.h b/src/shared/att-types.h
index 7b88e7d92..cc9cc9fd6 100644
--- a/src/shared/att-types.h
+++ b/src/shared/att-types.h
@@ -75,6 +75,8 @@
#define BT_ATT_OP_HANDLE_VAL_NOT 0x1B
#define BT_ATT_OP_HANDLE_VAL_IND 0x1D
#define BT_ATT_OP_HANDLE_VAL_CONF 0x1E
+#define BT_ATT_OP_READ_MULT_VL_REQ 0x20
+#define BT_ATT_OP_READ_MULT_VL_RSP 0x21
/* Packed struct definitions for ATT protocol PDUs */
/* TODO: Complete these definitions for all opcodes */
diff --git a/src/shared/gatt-server.c b/src/shared/gatt-server.c
index ee0058486..55535abdf 100644
--- a/src/shared/gatt-server.c
+++ b/src/shared/gatt-server.c
@@ -102,6 +102,7 @@ struct bt_gatt_server {
unsigned int read_id;
unsigned int read_blob_id;
unsigned int read_multiple_id;
+ unsigned int read_multiple_vl_id;
unsigned int prep_write_id;
unsigned int exec_write_id;
@@ -136,6 +137,7 @@ static void bt_gatt_server_free(struct bt_gatt_server *server)
bt_att_unregister(server->att, server->read_id);
bt_att_unregister(server->att, server->read_blob_id);
bt_att_unregister(server->att, server->read_multiple_id);
+ bt_att_unregister(server->att, server->read_multiple_vl_id);
bt_att_unregister(server->att, server->prep_write_id);
bt_att_unregister(server->att, server->exec_write_id);
@@ -1013,9 +1015,10 @@ static void read_blob_cb(struct bt_att_chan *chan, uint8_t opcode,
handle_read_req(chan, server, opcode, handle, offset);
}
-struct read_multiple_resp_data {
+struct read_mult_data {
struct bt_att_chan *chan;
struct bt_gatt_server *server;
+ uint8_t opcode;
uint16_t *handles;
size_t cur_handle;
size_t num_handles;
@@ -1024,7 +1027,7 @@ struct read_multiple_resp_data {
size_t mtu;
};
-static void read_multiple_resp_data_free(struct read_multiple_resp_data *data)
+static void read_mult_data_free(struct read_mult_data *data)
{
free(data->handles);
free(data->rsp_data);
@@ -1035,15 +1038,16 @@ static void read_multiple_complete_cb(struct gatt_db_attribute *attr, int err,
const uint8_t *value, size_t len,
void *user_data)
{
- struct read_multiple_resp_data *data = user_data;
+ struct read_mult_data *data = user_data;
struct gatt_db_attribute *next_attr;
uint16_t handle = gatt_db_attribute_get_handle(attr);
uint8_t ecode;
+ uint16_t length;
if (err != 0) {
- bt_att_chan_send_error_rsp(data->chan,
- BT_ATT_OP_READ_MULT_REQ, handle, err);
- read_multiple_resp_data_free(data);
+ bt_att_chan_send_error_rsp(data->chan, data->opcode, handle,
+ err);
+ read_mult_data_free(data);
return;
}
@@ -1051,29 +1055,45 @@ static void read_multiple_complete_cb(struct gatt_db_attribute *attr, int err,
BT_ATT_PERM_READ_AUTHEN |
BT_ATT_PERM_READ_ENCRYPT);
if (ecode) {
- bt_att_chan_send_error_rsp(data->chan,
- BT_ATT_OP_READ_MULT_REQ, handle, ecode);
- read_multiple_resp_data_free(data);
+ bt_att_chan_send_error_rsp(data->chan, data->opcode, handle,
+ ecode);
+ read_mult_data_free(data);
return;
}
- len = MIN(len, data->mtu - data->length - 1);
+ length = data->opcode == BT_ATT_OP_READ_MULT_VL_REQ ?
+ MIN(len, data->mtu - data->length - 3) :
+ MIN(len, data->mtu - data->length - 1);
- memcpy(data->rsp_data + data->length, value, len);
- data->length += len;
+ if (data->opcode == BT_ATT_OP_READ_MULT_VL_REQ) {
+ /* The Length Value Tuple List may be truncated within the first
+ * two octets of a tuple due to the size limits of the current
+ * ATT_MTU.
+ */
+ put_le16(len, data->rsp_data + data->length);
+ data->length += 2;
+ }
+
+ memcpy(data->rsp_data + data->length, value, length);
+ data->length += length;
data->cur_handle++;
- if ((data->length >= data->mtu - 1) ||
- (data->cur_handle == data->num_handles)) {
- bt_att_chan_send_rsp(data->chan, BT_ATT_OP_READ_MULT_RSP,
+ len = data->opcode == BT_ATT_OP_READ_MULT_VL_REQ ?
+ data->mtu - data->length - 3 : data->mtu - data->length - 1;
+
+ if (!len || (data->cur_handle == data->num_handles)) {
+ bt_att_chan_send_rsp(data->chan, data->opcode + 1,
data->rsp_data, data->length);
- read_multiple_resp_data_free(data);
+ read_mult_data_free(data);
return;
}
util_debug(data->server->debug_callback, data->server->debug_data,
- "Read Multiple Req - #%zu of %zu: 0x%04x",
+ "%s Req - #%zu of %zu: 0x%04x",
+ data->opcode == BT_ATT_OP_READ_MULT_REQ ?
+ "Read Multiple" :
+ "Read Multiple Variable Length",
data->cur_handle + 1, data->num_handles,
data->handles[data->cur_handle]);
@@ -1085,7 +1105,7 @@ static void read_multiple_complete_cb(struct gatt_db_attribute *attr, int err,
BT_ATT_OP_READ_MULT_REQ,
data->handles[data->cur_handle],
BT_ATT_ERROR_INVALID_HANDLE);
- read_multiple_resp_data_free(data);
+ read_mult_data_free(data);
return;
}
@@ -1096,17 +1116,40 @@ static void read_multiple_complete_cb(struct gatt_db_attribute *attr, int err,
BT_ATT_OP_READ_MULT_REQ,
data->handles[data->cur_handle],
BT_ATT_ERROR_UNLIKELY);
- read_multiple_resp_data_free(data);
+ read_mult_data_free(data);
}
}
+static struct read_mult_data *read_mult_data_new(struct bt_gatt_server *server,
+ struct bt_att_chan *chan,
+ uint8_t opcode,
+ uint16_t num_handles)
+{
+ struct read_mult_data *data;
+
+ data = new0(struct read_mult_data, 1);
+ data->chan = chan;
+ data->opcode = opcode;
+ data->handles = new0(uint16_t, num_handles);
+ data->handles = NULL;
+ data->rsp_data = NULL;
+ data->server = server;
+ data->num_handles = num_handles;
+ data->cur_handle = 0;
+ data->mtu = bt_att_get_mtu(server->att);
+ data->length = 0;
+ data->rsp_data = new0(uint8_t, data->mtu - 1);
+
+ return data;
+}
+
static void read_multiple_cb(struct bt_att_chan *chan, uint8_t opcode,
const void *pdu, uint16_t length,
void *user_data)
{
struct bt_gatt_server *server = user_data;
struct gatt_db_attribute *attr;
- struct read_multiple_resp_data *data = NULL;
+ struct read_mult_data *data = NULL;
uint8_t ecode = BT_ATT_ERROR_UNLIKELY;
size_t i = 0;
@@ -1115,18 +1158,8 @@ static void read_multiple_cb(struct bt_att_chan *chan, uint8_t opcode,
goto error;
}
- data = new0(struct read_multiple_resp_data, 1);
- data->chan = chan;
- data->handles = NULL;
- data->rsp_data = NULL;
- data->server = server;
- data->num_handles = length / 2;
- data->cur_handle = 0;
- data->mtu = bt_att_get_mtu(server->att);
- data->length = 0;
- data->rsp_data = malloc(data->mtu - 1);
-
- if (!data->rsp_data)
+ data = read_mult_data_new(server, chan, opcode, length / 2);
+ if (!data)
goto error;
data->handles = new0(uint16_t, data->num_handles);
@@ -1135,7 +1168,9 @@ static void read_multiple_cb(struct bt_att_chan *chan, uint8_t opcode,
data->handles[i] = get_le16(pdu + i * 2);
util_debug(server->debug_callback, server->debug_data,
- "Read Multiple Req - %zu handles, 1st: 0x%04x",
+ "%s Req - %zu handles, 1st: 0x%04x",
+ data->opcode == BT_ATT_OP_READ_MULT_REQ ?
+ "Read Multiple" : "Read Multiple Variable Length",
data->num_handles, data->handles[0]);
attr = gatt_db_get_attribute(server->db, data->handles[0]);
@@ -1151,7 +1186,7 @@ static void read_multiple_cb(struct bt_att_chan *chan, uint8_t opcode,
error:
if (data)
- read_multiple_resp_data_free(data);
+ read_mult_data_free(data);
bt_att_chan_send_error_rsp(chan, opcode, 0, ecode);
}
@@ -1588,6 +1623,15 @@ static bool gatt_server_register_att_handlers(struct bt_gatt_server *server)
if (!server->read_multiple_id)
return false;
+ /* Read Multiple Variable Length Request */
+ server->read_multiple_vl_id = bt_att_register(server->att,
+ BT_ATT_OP_READ_MULT_VL_REQ,
+ read_multiple_cb,
+ server, NULL);
+
+ if (!server->read_multiple_vl_id)
+ return false;
+
/* Prepare Write Request */
server->prep_write_id = bt_att_register(server->att,
BT_ATT_OP_PREP_WRITE_REQ,
--
2.21.0
