From: Curtis Maves <curtis@maves.io>
To: "Luiz Augusto von Dentz" <luiz.dentz@gmail.com>
Cc: "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>
Subject: Re: [PATCH BlueZ] gatt-database: Fix notifying on indicatable attr
Date: Sat, 20 Feb 2021 13:29:10 -0500 [thread overview]
Message-ID: <177c0b3e32a.c0b69e35170119.443115256308628377@maves.io> (raw)
In-Reply-To: <CABBYNZJJiXJJqtRMXKEvpwN-mj=eht9wdTgrK1p_Fo_36gK4Zw@mail.gmail.com>
Hi Luiz,
---- On Sat, 20 Feb 2021 01:07:57 -0500 Luiz Augusto von Dentz <luiz.dentz@gmail.com> wrote ----
> Hi Curtis,
>
> On Fri, Feb 19, 2021 at 5:18 PM Curtis Maves <curtis@maves.io> wrote:
> >
> > Hi Luiz,
> > ---- On Fri, 19 Feb 2021 19:55:06 -0500 Luiz Augusto von Dentz <luiz.dentz@gmail.com> wrote ----
> >
> > > Hi Curtis,
> > >
> > > On Fri, Feb 19, 2021 at 10:11 AM Curtis <curtis@maves.io> wrote:
> > > >
> > > > When a local GATT characteristic has both the indicate and notify
> > > > properties, notifications will not be send to clients requesting them.
> > > > This change fixes this, allowing for notifications to be sent.
> > > >
> > > > Also simplifies logic about when notifications/indications should
> > > > be sent.
> > > > ---
> > > > src/gatt-database.c | 15 ++++++---------
> > > > 1 file changed, 6 insertions(+), 9 deletions(-)
> > > >
> > > > diff --git a/src/gatt-database.c b/src/gatt-database.c
> > > > index d635c3214..bd5864bcd 100644
> > > > --- a/src/gatt-database.c
> > > > +++ b/src/gatt-database.c
> > > > @@ -1344,10 +1344,7 @@ static void send_notification_to_device(void *data, void *user_data)
> > > > }
> > > >
> > > > ccc = find_ccc_state(device_state, notify->ccc_handle);
> > > > - if (!ccc)
> > > > - return;
> > > > -
> > > > - if (!ccc->value || (notify->conf && !(ccc->value & 0x0002)))
> > > > + if (!ccc || !(ccc->value & 0x0003))
> > > > return;
> > > >
> > > > device = btd_adapter_find_device(notify->database->adapter,
> > > > @@ -1374,7 +1371,7 @@ static void send_notification_to_device(void *data, void *user_data)
> > > > * TODO: If the device is not connected but bonded, send the
> > > > * notification/indication when it becomes connected.
> > > > */
> > > > - if (!notify->conf) {
> > > > + if (!(ccc->value & 0x0002)) {
> > > > DBG("GATT server sending notification");
> > > > bt_gatt_server_send_notification(server,
> > > > notify->handle, notify->value,
> > > > @@ -2415,8 +2412,8 @@ static bool sock_io_read(struct io *io, void *user_data)
> > > > gatt_db_attribute_get_handle(chrc->attrib),
> > > > buf, bytes_read,
> > > > gatt_db_attribute_get_handle(chrc->ccc),
> > > > - chrc->props & BT_GATT_CHRC_PROP_INDICATE ?
> > > > - conf_cb : NULL, chrc->proxy);
> > > > + conf_cb,
> > > > + chrc->proxy);
> > >
> > > Not why are you changing this code to always set the conf_cb? This
> > > would then always send indication rather then notifications:
> > >
> > > https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/src/gatt-database.c#n1387
> > >
> > > We might need to check what value it stored in the ccc state if both
> > > indication and notification is supported.
> > >
> > > >
> > > > return true;
> > > > }
> > > > @@ -2725,8 +2722,8 @@ static void property_changed_cb(GDBusProxy *proxy, const char *name,
> > > > gatt_db_attribute_get_handle(chrc->attrib),
> > > > value, len,
> > > > gatt_db_attribute_get_handle(chrc->ccc),
> > > > - chrc->props & BT_GATT_CHRC_PROP_INDICATE ?
> > > > - conf_cb : NULL, proxy);
> > > > + conf_cb,
> > > > + proxy);
> > > > }
> > > >
> > > > static bool database_add_ccc(struct external_service *service,
> > > > --
> > > > 2.30.1
> > > >
> > > >
> > >
> > >
> > > --
> > > Luiz Augusto von Dentz
> > >
> >
> > This patch changes the if-statement around sending notifications to check that the
> > ccc->value is not indicating rather than checking if conf_cb (notify->conf) is null.
> > This change makes unnecessary to conditionally pass the conf_cb. It's now simpler to always pass it.
>
> What Im saying is that we can't do this:
>
> if (!notify->conf) {
> DBG("GATT server sending notification");
>
> conf callback will always be set so instead we need to change that to:
>
> if (ccc->value != 0x02)
>
>
>
> > --
> > Curtis Maves
>
>
>
> --
> Luiz Augusto von Dentz
>
I agree that we can no longer do the following on line 1377:
> if (!notify->conf) {
> DBG("GATT server sending notification");
As you said the ccc value needs to be tested instead.
This part of the patch already makes a change similar to what you suggested:
> > > > @@ -1374,7 +1371,7 @@ static void send_notification_to_device(void *data, void *user_data)
> > > > * TODO: If the device is not connected but bonded, send the
> > > > * notification/indication when it becomes connected.
> > > > */
> > > > - if (!notify->conf) {
> > > > + if (!(ccc->value & 0x0002)) {
Is there anywhere else where notify->conf is checked?
I looked around but did not find any on my own.
--
Curtis Maves
next prev parent reply other threads:[~2021-02-20 18:30 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-19 17:49 [PATCH BlueZ] gatt-database: Fix notifying on indicatable attr Curtis
2021-02-19 18:37 ` [BlueZ] " bluez.test.bot
2021-02-20 0:55 ` [PATCH BlueZ] " Luiz Augusto von Dentz
2021-02-20 1:18 ` Curtis Maves
2021-02-20 6:07 ` Luiz Augusto von Dentz
2021-02-20 18:29 ` Curtis Maves [this message]
2021-02-22 18:24 ` Luiz Augusto von Dentz
2021-02-22 18:26 ` Luiz Augusto von Dentz
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