Hi Johan,
> We need to have a way of updating the local RPA periodically. This patch
> adds a HCI_RPA_EXPIRED flag to track when the RPA needs to be
> regenerated as well as a delayed work structure and callback to do the
> updating periodically. By default the period for updating the RPA is set
> to 15 minutes.
>
> When the RPA gets regenerated we need to disable and re-enable
> advertising if necessary. If there are any LE connections we do not
> update the RPA.
>
> Signed-off-by: Johan Hedberg <johan.hedberg@xxxxxxxxx>
> ---
> include/net/bluetooth/hci.h | 1 +
> include/net/bluetooth/hci_core.h | 7 +++++++
> net/bluetooth/hci_core.c | 25 +++++++++++++++++++++++++
> net/bluetooth/mgmt.c | 23 +++++++++++++++++++++++
> 4 files changed, 56 insertions(+)
>
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index 5ff885ff29df..1bb45a47a78a 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -127,6 +127,7 @@ enum {
> HCI_SC_ENABLED,
> HCI_SC_ONLY,
> HCI_PRIVACY,
> + HCI_RPA_EXPIRED,
> HCI_RPA_RESOLVING,
> HCI_HS_ENABLED,
> HCI_LE_ENABLED,
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index 68bbcabdd9fd..94383dca6597 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -130,6 +130,9 @@ struct oob_data {
>
> #define HCI_MAX_SHORT_NAME_LENGTH 10
>
> +/* Default LE RPA expiry time, 15 minutes */
> +#define HCI_DEFAULT_RPA_TIMEOUT (15 * 60)
> +
> struct amp_assoc {
> __u16 len;
> __u16 offset;
> @@ -304,6 +307,8 @@ struct hci_dev {
> __u8 scan_rsp_data_len;
>
> __u8 irk[16];
> + __u32 rpa_timeout;
> + struct delayed_work rpa_expired;
>
> int (*open)(struct hci_dev *hdev);
> int (*close)(struct hci_dev *hdev);
> @@ -1252,6 +1257,8 @@ void hci_le_conn_update(struct hci_conn *conn, u16 min, u16 max,
> void hci_le_start_enc(struct hci_conn *conn, __le16 ediv, __u8 rand[8],
> __u8 ltk[16]);
>
> +void hci_update_rpa(struct hci_request *req);
> +
> #define SCO_AIRMODE_MASK 0x0003
> #define SCO_AIRMODE_CVSD 0x0000
> #define SCO_AIRMODE_TRANSP 0x0003
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index 753a73ba6764..eeeeda7e6b70 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -2202,6 +2202,9 @@ static int hci_dev_do_close(struct hci_dev *hdev)
>
> cancel_delayed_work_sync(&hdev->le_scan_disable);
>
> + cancel_delayed_work_sync(&hdev->rpa_expired);
> + set_bit(HCI_RPA_EXPIRED, &hdev->dev_flags);
> +
why on power down. Why not just set this on power up.
> hci_dev_lock(hdev);
> hci_inquiry_cache_flush(hdev);
> hci_conn_hash_flush(hdev);
> @@ -3276,6 +3279,26 @@ static void le_scan_disable_work(struct work_struct *work)
> BT_ERR("Disable LE scanning request failed: err %d", err);
> }
>
> +void hci_update_rpa(struct hci_request *req)
> +{
> + struct hci_dev *hdev = req->hdev;
> + bdaddr_t rpa;
> +
> + if (smp_generate_rpa(hdev->tfm_aes, hdev->irk, &rpa) < 0) {
> + BT_ERR("%s failed to generate new RPA", hdev->name);
> + return;
> + }
> +
> + hci_req_add(req, HCI_OP_LE_SET_RANDOM_ADDR, 6, &rpa);
> +
> + if (hdev->rpa_timeout) {
> + int to;
> +
> + to = msecs_to_jiffies(hdev->rpa_timeout * 1000);
I thought our rpa_timeout is in minutes? Are we allowing second granularity? I have nothing against it, but it will be rather useless to have a device that changes its RPA every second.
> + queue_delayed_work(hdev->workqueue, &hdev->rpa_expired, to);
> + }
> +}
> +
> /* Alloc HCI device */
> struct hci_dev *hci_alloc_dev(void)
> {
> @@ -3302,6 +3325,8 @@ struct hci_dev *hci_alloc_dev(void)
> hdev->le_conn_min_interval = 0x0028;
> hdev->le_conn_max_interval = 0x0038;
>
> + hdev->rpa_timeout = HCI_DEFAULT_RPA_TIMEOUT;
> +
> mutex_init(&hdev->lock);
> mutex_init(&hdev->req_lock);
>
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index 21d059968c32..248f116e3d08 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -882,12 +882,35 @@ static void service_cache_off(struct work_struct *work)
> hci_req_run(&req, NULL);
> }
>
> +static void rpa_expired(struct work_struct *work)
> +{
> + struct hci_dev *hdev = container_of(work, struct hci_dev,
> + rpa_expired.work);
> + struct hci_request req;
> +
> + BT_DBG("");
> +
> + set_bit(HCI_RPA_EXPIRED, &hdev->dev_flags);
> +
> + if (!test_bit(HCI_ADVERTISING, &hdev->dev_flags) ||
> + hci_conn_num(hdev, LE_LINK) > 0)
> + return;
> +
> + hci_req_init(&req, hdev);
> +
> + disable_advertising(&req);
> + enable_advertising(&req);
> +
might want to add a comment that the RPA gets regenerated when enabling advertising. Just to make it easy for everybody to get that this code does the right thing.
> + hci_req_run(&req, NULL);
> +}
> +
> static void mgmt_init_hdev(struct sock *sk, struct hci_dev *hdev)
> {
> if (test_and_set_bit(HCI_MGMT, &hdev->dev_flags))
> return;
>
> INIT_DELAYED_WORK(&hdev->service_cache, service_cache_off);
> + INIT_DELAYED_WORK(&hdev->rpa_expired, rpa_expired);
>
> /* Non-mgmt controlled devices get this bit set
> * implicitly so that pairing works for them, however
We should set the RPA_EXPIRED bit here.
Regards
Marcel
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