Hi Luiz,
>>> This adds support for Set Privacy Mode when updating the resolving list
>>> when HCI_LIMITED_PRIVACY so the controller shall use Device Mode for
>>> devices programmed in the resolving list, Device Mode is actually
>>> required when the remote device are not able to use RPA as otherwise the
>>> default mode is Network Privacy Mode in which only RPA are allowed thus
>>> the controller would filter out advertisement using the identity address
>>> for which there is an IRK.
>>>
>>> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
>>> ---
>>> include/net/bluetooth/hci.h | 7 ++++++
>>> net/bluetooth/hci_sync.c | 48 ++++++++++++++++++++++++++++++++-----
>>> 2 files changed, 49 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
>>> index 63065bc01b76..aa856dfd5b9f 100644
>>> --- a/include/net/bluetooth/hci.h
>>> +++ b/include/net/bluetooth/hci.h
>>> @@ -1930,6 +1930,13 @@ struct hci_rp_le_read_transmit_power {
>>> __s8 max_le_tx_power;
>>> } __packed;
>>>
>>> +#define HCI_OP_LE_SET_PRIVACY_MODE 0x204e
>>> +struct hci_cp_le_set_privacy_mode {
>>> + __u8 bdaddr_type;
>>> + bdaddr_t bdaddr;
>>> + __u8 mode;
>>> +} __packed;
>>> +
>>> #define HCI_OP_LE_READ_BUFFER_SIZE_V2 0x2060
>>> struct hci_rp_le_read_buffer_size_v2 {
>>> __u8 status;
>>> diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
>>> index b794605dc882..43173d645436 100644
>>> --- a/net/bluetooth/hci_sync.c
>>> +++ b/net/bluetooth/hci_sync.c
>>> @@ -1580,8 +1580,37 @@ static int hci_le_add_resolve_list_sync(struct hci_dev *hdev,
>>> sizeof(cp), &cp, HCI_CMD_TIMEOUT);
>>> }
>>>
>>> +/* Set Device Privacy Mode. */
>>> +static int hci_le_set_privacy_mode_sync(struct hci_dev *hdev,
>>> + struct hci_conn_params *params)
>>> +{
>>> + struct hci_cp_le_set_privacy_mode cp;
>>> + struct smp_irk *irk;
>>> +
>>> + /* Set Privacy Mode requires the use of resolving list (aka. LL Privacy)
>>> + * by default Network Mode is used so only really send the command if
>>> + * Device Mode is required (HCI_LIMITED_PRIVACY).
>>> + */
>>> + if (!use_ll_privacy(hdev) ||
>>> + !hci_dev_test_flag(hdev, HCI_LIMITED_PRIVACY))
>>> + return 0;
>>> +
>>> + irk = hci_find_irk_by_addr(hdev, ¶ms->addr, params->addr_type);
>>> + if (!irk)
>>> + return 0;
>>> +
>>> + memset(&cp, 0, sizeof(cp));
>>> + cp.bdaddr_type = irk->addr_type;
>>> + bacpy(&cp.bdaddr, &irk->bdaddr);
>>> + cp.mode = 0x01;
>>> +
>>
>> you need to check if this command is actually supported.
>
> The spec suggests it is mandatory if LL Privacy is supported:
>
> 'C9: Mandatory if LE Feature (LL Privacy) is supported, otherwise excluded.'
and what about Bluetooth 4.2 spec. devices? Not all earlier specs have both features.
>> I think the best option is to add it to Set Device Flags and let bluetoothd set it on a per device basis like it does with the wakeup flag.
>
> Got it, I guess
I prefer Set Device Flags since with Get Device Flags you can indicate if this is supported or not.
>> Trying to tie it to the Limited Privacy mode seems weird. Since that is for discoverability and this is for outgoing connections.
>
> Hmm, I'm afraid this wouldn't follow the spec to the letter then since
> it doesn't actually split Incoming/advertising and Outgoing/scanning
> privacy, it does seems to be global so if we go with different
> settings to control each direction separately we may end up with a
> custom mode e.g: limited discoverability for advertising vs network
> privacy mode for scanning, for instance limited discoverability does
> blast the public address while discoverable and bondable but both
> privacy modes seems to require the use of RPA, anyway it would
> probably be a good idea to document the interactions, also main.conf
> seem to have gone with privacy from the specification so we may either
> need add more modes:
>
> Privacy:
> "on"/"network": Apply Network Privacy Mode both for advertising and scanning
> "limited-network": Apply Limited Discoverable Mode to advertising and
> Network Privacy Mode for scanning
> "device": Apply Device Privacy Mode both for advertising and scanning
> "limited-device": Apply Limited Discoverable Mode to advertising and
> Device Privacy Mode for scanning
Then we can do that and use Limited Privacy mode for exactly that. However in addition I would use the Set Device Flags to allow punching holes for specific devices.
Regards
Marcel
