Hi Szymon,
>>> Append maximum of 10 + 1 bytes of name to scan response data.
>>> Complete name is appended only if exists and is <= 10 characters.
>>> Else append short name if exists or shorten complete name if not.
>>> This makes sure name is consistent across multiple advertising
>>> instances.
>>>
>>> Signed-off-by: Michał Narajowski <michal.narajowski@xxxxxxxxxxx>
>>> ---
>>> net/bluetooth/hci_request.c | 47 +++++++++++++++++++++------------------------
>>> net/bluetooth/mgmt.c | 4 ++--
>>> 2 files changed, 24 insertions(+), 27 deletions(-)
>>>
>>> diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
>>> index e228842..cfdd2c8 100644
>>> --- a/net/bluetooth/hci_request.c
>>> +++ b/net/bluetooth/hci_request.c
>>> @@ -971,39 +971,36 @@ void __hci_req_enable_advertising(struct hci_request *req)
>>>
>>> static u8 append_local_name(struct hci_dev *hdev, u8 *ptr, u8 ad_len)
>>> {
>>> - size_t complete_len;
>>> size_t short_len;
>>> - int max_len;
>>> -
>>> - max_len = HCI_MAX_AD_LENGTH - ad_len - 2;
>>> - complete_len = strlen(hdev->dev_name);
>>> - short_len = strlen(hdev->short_name);
>>> -
>>> - /* no space left for name */
>>> - if (max_len < 1)
>>> - return ad_len;
>>> + size_t complete_len;
>>>
>>> - /* no name set */
>>> - if (!complete_len)
>>> + /* no space left for name (+ NULL + type + len) */
>>> + if ((HCI_MAX_AD_LENGTH - ad_len) < HCI_MAX_SHORT_NAME_LENGTH + 3)
>>> return ad_len;
>>>
>>> - /* complete name fits and is eq to max short name len or smaller */
>>> - if (complete_len <= max_len &&
>>> - complete_len <= HCI_MAX_SHORT_NAME_LENGTH) {
>>> + /* use complete name if present and fits */
>>> + complete_len = strlen(hdev->dev_name);
>>> + if (complete_len && complete_len <= HCI_MAX_SHORT_NAME_LENGTH)
>>> return eir_append_data(ptr, ad_len, EIR_NAME_COMPLETE,
>>> - hdev->dev_name, complete_len);
>>> - }
>>> + hdev->dev_name, complete_len + 1);
>>>
>>> - /* short name set and fits */
>>> - if (short_len && short_len <= max_len) {
>>> + /* use short name if present */
>>> + short_len = strlen(hdev->short_name);
>>> + if (short_len)
>>> return eir_append_data(ptr, ad_len, EIR_NAME_SHORT,
>>> - hdev->short_name, short_len);
>>> - }
>>> + hdev->short_name, short_len + 1);
>>>
>>> - /* no short name set so shorten complete name */
>>> - if (!short_len) {
>>> - return eir_append_data(ptr, ad_len, EIR_NAME_SHORT,
>>> - hdev->dev_name, max_len);
>>> + /* use shortened full name if present, we already know that name
>>> + * is longer then HCI_MAX_SHORT_NAME_LENGTH
>>> + */
>>> + if (complete_len) {
>>> + u8 name[HCI_MAX_SHORT_NAME_LENGTH + 1];
>>> +
>>> + memcpy(name, hdev->dev_name, HCI_MAX_SHORT_NAME_LENGTH);
>>> + name[HCI_MAX_SHORT_NAME_LENGTH] = '\0';
>>> +
>>> + return eir_append_data(ptr, ad_len, EIR_NAME_SHORT, name,
>>> + sizeof(name));
>>> }
>>>
>>> return ad_len;
>>> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
>>> index 7360380..cdcadca 100644
>>> --- a/net/bluetooth/mgmt.c
>>> +++ b/net/bluetooth/mgmt.c
>>> @@ -6030,9 +6030,9 @@ static u8 tlv_data_max_len(u32 adv_flags, bool is_adv_data)
>>> if (adv_flags & MGMT_ADV_FLAG_TX_POWER)
>>> max_len -= 3;
>>> } else {
>>> - /* at least 1 byte of name should fit in */
>>> + /* max 11 bytes of name should fit in */
>>> if (adv_flags & MGMT_ADV_FLAG_LOCAL_NAME)
>>> - max_len -= 3;
>>> + max_len -= (1 + 1 + 11);
>>
>> actually this one should also return correct values and not just max.
>>
>> If either the full_name or short_name is shorter than 11 octets, then only that value should be returned instead of always 11 octets.
>
> This would mean that if name is changed userspace will have to query
> this again (and track name changes from mgmt). If that is the case we
> should probably document this behavior.
that is what I would expect. And yes, documenting this would be a good idea.
Regards
Marcel
--
To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
