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Bluetooth: controller: Fix access address generation

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Fix access address generation to correctly have two
transitions in the six MS bits and add other missing checks.

Signed-off-by: Vinayak Kariappa Chettimada <vich@nordicsemi.no>
This commit is contained in:
Vinayak Kariappa Chettimada 2017-07-17 13:36:03 +02:00 • committed by Johan Hedberg
commit f80344f0fe
1 changed files with 37 additions and 13 deletions
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50
subsys/bluetooth/controller/ll_sw/ctrl.c
View file

@ -4800,13 +4800,27 @@ static void chan_set(u32_t chan)
*/
static u32_t access_addr_get(void)
{
u32_t access_addr;
u8_t bit_idx;
u8_t transitions;
u8_t consecutive_cnt;
u8_t consecutive_bit;
u32_t adv_aa_check;
u32_t access_addr;
u8_t transitions;
u8_t bit_idx;
u8_t retry;
u8_t len;
rand_get(sizeof(u32_t), (u8_t *)&access_addr);
retry = 3;
again:
LL_ASSERT(retry);
retry--;
len = sizeof(u32_t);
while (len) {
len = rand_get(len, (u8_t *)&access_addr);
if (len) {
cpu_sleep();
}
}
bit_idx = 31;
transitions = 0;
@ -4828,14 +4842,15 @@ static u32_t access_addr_get(void)
/* It shall have a minimum of two transitions in the most
* significant six bits.
*/
if ((consecutive_cnt > 6)
|| ((bit_idx < 28) && (transitions < 2))) {
if ((consecutive_cnt > 6) ||
((bit_idx < 28) && (transitions < 1)) ||
((bit_idx < 27) && (transitions < 2))) {
if (consecutive_bit) {
consecutive_bit = 0;
access_addr &= ~(1 << bit_idx);
access_addr &= ~BIT(bit_idx);
} else {
consecutive_bit = 1;
access_addr |= (1 << bit_idx);
access_addr |= BIT(bit_idx);
}
consecutive_cnt = 1;
@ -4845,21 +4860,30 @@ static u32_t access_addr_get(void)
/* It shall have no more than 24 transitions */
if (transitions > 24) {
if (consecutive_bit) {
access_addr &= ~((1 << (bit_idx + 1)) - 1);
access_addr &= ~(BIT(bit_idx + 1) - 1);
} else {
access_addr |= ((1 << (bit_idx + 1)) - 1);
access_addr |= (BIT(bit_idx + 1) - 1);
}
break;
}
}
/** @todo proper access address calculations
* It shall not be the advertising channel packets Access Address.
/* It shall not be the advertising channel packets Access Address.
* It shall not be a sequence that differs from the advertising channel
* packets Access Address by only one bit.
* It shall not have all four octets equal.
*/
adv_aa_check = access_addr ^ 0x8e89bed6;
if (util_ones_count_get((u8_t *)&adv_aa_check,
sizeof(adv_aa_check)) <= 1) {
goto again;
}
/* It shall not have all four octets equal. */
if (!((access_addr & 0xFFFF) ^ (access_addr >> 16)) &&
!((access_addr & 0xFF) ^ (access_addr >> 24))) {
goto again;
}
return access_addr;
}