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Bluetooth: ATT: Refactor PDU handling

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Mark each PDU type explicitly instead of using BT_ATT_OP_CMD_FLAG for
this. For simple "error response or not" selection the command flag is
sufficient, but to prepare for support for enforcing both request and
indication flow control it's useful to easily look up the type of the
PDU.

Additionally, refactor the handler lookup to make the flow a bit more
streamlined.

Change-Id: I575848356934b6d636dcda8d10b7e7fde1095355
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This commit is contained in:
Johan Hedberg 2017-03-17 13:21:20 +02:00
commit bb975d3af6
1 changed files with 51 additions and 18 deletions
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69
subsys/bluetooth/host/att.c
View file

@ -42,7 +42,6 @@
BT_GATT_PERM_WRITE_ENCRYPT)
#define BT_GATT_PERM_AUTHEN_MASK (BT_GATT_PERM_READ_AUTHEN | \
BT_GATT_PERM_WRITE_AUTHEN)
#define BT_ATT_OP_CMD_FLAG 0x40
#define ATT_TIMEOUT K_SECONDS(30)
@ -1601,92 +1600,127 @@ static uint8_t att_confirm(struct bt_att *att, struct net_buf *buf)
return att_handle_rsp(att, buf->data, buf->len, 0);
}
static const struct {
static const struct att_handler {
uint8_t op;
uint8_t expect_len;
enum __packed {
ATT_COMMAND,
ATT_REQUEST,
ATT_RESPONSE,
ATT_NOTIFICATION,
ATT_CONFIRMATION,
ATT_INDICATION,
} type;
uint8_t (*func)(struct bt_att *att, struct net_buf *buf);
} handlers[] = {
{ BT_ATT_OP_ERROR_RSP,
sizeof(struct bt_att_error_rsp),
ATT_RESPONSE,
att_error_rsp },
{ BT_ATT_OP_MTU_REQ,
sizeof(struct bt_att_exchange_mtu_req),
ATT_REQUEST,
att_mtu_req },
{ BT_ATT_OP_MTU_RSP,
sizeof(struct bt_att_exchange_mtu_rsp),
ATT_RESPONSE,
att_mtu_rsp },
{ BT_ATT_OP_FIND_INFO_REQ,
sizeof(struct bt_att_find_info_req),
ATT_REQUEST,
att_find_info_req },
{ BT_ATT_OP_FIND_INFO_RSP,
sizeof(struct bt_att_find_info_rsp),
ATT_RESPONSE,
att_handle_find_info_rsp },
{ BT_ATT_OP_FIND_TYPE_REQ,
sizeof(struct bt_att_find_type_req),
ATT_REQUEST,
att_find_type_req },
{ BT_ATT_OP_FIND_TYPE_RSP,
sizeof(struct bt_att_find_type_rsp),
ATT_RESPONSE,
att_handle_find_type_rsp },
{ BT_ATT_OP_READ_TYPE_REQ,
sizeof(struct bt_att_read_type_req),
ATT_REQUEST,
att_read_type_req },
{ BT_ATT_OP_READ_TYPE_RSP,
sizeof(struct bt_att_read_type_rsp),
ATT_RESPONSE,
att_handle_read_type_rsp },
{ BT_ATT_OP_READ_REQ,
sizeof(struct bt_att_read_req),
ATT_REQUEST,
att_read_req },
{ BT_ATT_OP_READ_RSP,
sizeof(struct bt_att_read_rsp),
ATT_RESPONSE,
att_handle_read_rsp },
{ BT_ATT_OP_READ_BLOB_REQ,
sizeof(struct bt_att_read_blob_req),
ATT_REQUEST,
att_read_blob_req },
{ BT_ATT_OP_READ_BLOB_RSP,
sizeof(struct bt_att_read_blob_rsp),
ATT_RESPONSE,
att_handle_read_blob_rsp },
{ BT_ATT_OP_READ_MULT_REQ,
BT_ATT_READ_MULT_MIN_LEN_REQ,
ATT_REQUEST,
att_read_mult_req },
{ BT_ATT_OP_READ_MULT_RSP,
sizeof(struct bt_att_read_mult_rsp),
ATT_RESPONSE,
att_handle_read_mult_rsp },
{ BT_ATT_OP_READ_GROUP_REQ,
sizeof(struct bt_att_read_group_req),
ATT_REQUEST,
att_read_group_req },
{ BT_ATT_OP_WRITE_REQ,
sizeof(struct bt_att_write_req),
ATT_REQUEST,
att_write_req },
{ BT_ATT_OP_WRITE_RSP,
0,
ATT_RESPONSE,
att_handle_write_rsp },
{ BT_ATT_OP_PREPARE_WRITE_REQ,
sizeof(struct bt_att_prepare_write_req),
ATT_REQUEST,
att_prepare_write_req },
{ BT_ATT_OP_PREPARE_WRITE_RSP,
sizeof(struct bt_att_prepare_write_rsp),
ATT_RESPONSE,
att_handle_prepare_write_rsp },
{ BT_ATT_OP_EXEC_WRITE_REQ,
sizeof(struct bt_att_exec_write_req),
ATT_REQUEST,
att_exec_write_req },
{ BT_ATT_OP_EXEC_WRITE_RSP,
0,
ATT_RESPONSE,
att_handle_exec_write_rsp },
{ BT_ATT_OP_NOTIFY,
sizeof(struct bt_att_notify),
ATT_NOTIFICATION,
att_notify },
{ BT_ATT_OP_INDICATE,
sizeof(struct bt_att_indicate),
ATT_INDICATION,
att_indicate },
{ BT_ATT_OP_CONFIRM,
0,
ATT_CONFIRMATION,
att_confirm },
{ BT_ATT_OP_WRITE_CMD,
sizeof(struct bt_att_write_cmd),
ATT_COMMAND,
att_write_cmd },
{ BT_ATT_OP_SIGNED_WRITE_CMD,
(sizeof(struct bt_att_write_cmd) +
sizeof(struct bt_att_signature)),
ATT_COMMAND,
att_signed_write_cmd },
};
@ -1694,7 +1728,8 @@ static void bt_att_recv(struct bt_l2cap_chan *chan, struct net_buf *buf)
{
struct bt_att *att = ATT_CHAN(chan);
struct bt_att_hdr *hdr = (void *)buf->data;
uint8_t err = BT_ATT_ERR_NOT_SUPPORTED;
const struct att_handler *handler;
uint8_t err;
size_t i;
if (buf->len < sizeof(*hdr)) {
@ -1706,28 +1741,26 @@ static void bt_att_recv(struct bt_l2cap_chan *chan, struct net_buf *buf)
net_buf_pull(buf, sizeof(*hdr));
for (i = 0; i < ARRAY_SIZE(handlers); i++) {
if (hdr->code != handlers[i].op) {
continue;
}
if (buf->len < handlers[i].expect_len) {
BT_ERR("Invalid len %u for code 0x%02x", buf->len,
hdr->code);
err = BT_ATT_ERR_INVALID_PDU;
for (i = 0, handler = NULL; i < ARRAY_SIZE(handlers); i++) {
if (hdr->code == handlers[i].op) {
handler = &handlers[i];
break;
}
err = handlers[i].func(att, buf);
break;
}
/* Commands don't have response */
if ((hdr->code & BT_ATT_OP_CMD_FLAG)) {
if (!handler) {
BT_WARN("Unknown ATT code 0x%02x", hdr->code);
return;
}
if (err) {
if (buf->len < handler->expect_len) {
BT_ERR("Invalid len %u for code 0x%02x", buf->len, hdr->code);
err = BT_ATT_ERR_INVALID_PDU;
} else {
err = handler->func(att, buf);
}
if (handler->type == ATT_REQUEST && err) {
BT_DBG("ATT error 0x%02x", err);
send_err_rsp(chan->conn, hdr->code, 0, err);
}