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bluetooth: hci_core: Fix conn params validity check

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Bluetooth Core Specification v5.0, Vol 2, Part E, 7.8.12:

"The Supervision_Timeout parameter defines the link supervision timeout
for the connection. The Supervision_Timeout in milliseconds shall be larger
than (1 + Conn_Latency) * Conn_Interval_Max * 2, where Conn_Interval_Max is
given in milliseconds."

Let's remember that:
conn_interval is given in units N * 1.25 ms
sup_timeout is given in units N * 10 ms

sup_timeout_ms > (1 + latency) * (conn_interval_ms * 2)
yields:
sup_timeout_n * 10 > (1 + latency) * (conn_interval_n * 1.25 * 2)
yields:
sup_timeout_n * 10 > (1 + latency) * (conn_interval_n * 2.5)
yields:
sup_timeout_n * 4 > (1 + latency) * (conn_interval_n)

Change-id: I30ac1d375a1baaa3e61f4c29b1165110599e1f7c
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
This commit is contained in:
Carles Cufi 2017-01-14 19:44:16 +01:00 • committed by Johan Hedberg
commit 93d7512215
1 changed files with 6 additions and 8 deletions
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14
subsys/bluetooth/host/hci_core.c
View file

@ -786,22 +786,20 @@ static void le_remote_feat_complete(struct net_buf *buf)
bool bt_le_conn_params_valid(const struct bt_le_conn_param *param)
{
/* All limits according to BT Core spec 5.0 [Vol 2, Part E, 7.8.12] */
if (param->interval_min > param->interval_max ||
param->interval_min < 6 || param->interval_max > 3200) {
return false;
}
/* Limits according to BT Core spec 4.2 [Vol 2, Part E, 7.8.12] */
if (param->timeout < 10 || param->timeout > 3200 ||
((2 * param->timeout) <
((1 + param->latency) * param->interval_max * 5))) {
if (param->latency > 499) {
return false;
}
/* Limits according to BT Core spec 4.2 [Vol 6, Part B, 4.5.1] */
if (param->latency > 499 ||
(((param->latency + 1) * param->interval_max) >
(param->timeout * 4))) {
if (param->timeout < 10 || param->timeout > 3200 ||
((4 * param->timeout) <=
((1 + param->latency) * param->interval_max))) {
return false;
}