Message-ID: <CABBYNZ+Bs2D9A_OMJ_JGH9yTiLiK_gUz07jBEEXd302Uh01KQQ@mail.gmail.com>
Date: Fri, 24 Oct 2025 09:47:12 -0400
From: Luiz Augusto von Dentz <luiz.dentz@...il.com>
To: Yang Li <yang.li@...ogic.com>
Cc: Marcel Holtmann <marcel@...tmann.org>, Johan Hedberg <johan.hedberg@...il.com>, 
	linux-bluetooth@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] Bluetooth: iso: fix socket matching ambiguity between
 BIS and CIS

Hi Yang,

On Fri, Oct 24, 2025 at 9:45 AM Luiz Augusto von Dentz
<luiz.dentz@...il.com> wrote:
>
> Hi Yang,
>
> On Thu, Oct 23, 2025 at 11:47 PM Yang Li <yang.li@...ogic.com> wrote:
> >
> > Hi Luiz,
> > A gentle ping, thanks.
> >
> > > Hi Luiz,
> > >> [ EXTERNAL EMAIL ]
> > >>
> > >> Hi Yang,
> > >>
> > >> On Sun, Aug 3, 2025 at 9:07 PM Yang Li <yang.li@...ogic.com> wrote:
> > >>> Hi Luiz,
> > >>>> [ EXTERNAL EMAIL ]
> > >>>>
> > >>>> Hi Yang,
> > >>>>
> > >>>> On Thu, Jul 31, 2025 at 4:00 AM Yang Li via B4 Relay
> > >>>> <devnull+yang.li.amlogic.com@...nel.org> wrote:
> > >>>>> From: Yang Li <yang.li@...ogic.com>
> > >>>>>
> > >>>>> When both BIS and CIS links exist, their sockets are in
> > >>>>> the BT_LISTEN state.
> > >>>> We probably need to introduce tests to iso-test that setup both then
> > >>>> to avoid reintroducing the problem.
> > >>>
> > >>> Since the coexistence of BIS sink and CIS sink is determined by
> > >>> application-level logic, it may be difficult to reproduce this scenario
> > >>> using iso-test.
> > >> Looks like you haven't look at what iso-tester tools tests do, that is
> > >> not tight to bluetoothd, it directly operates at the socket layer so
> > >> we can create any scenario we want.
> > >
> > >
> > > Based on the current structure of iso-tester, it is not possible to
> > > implement test cases where CIS and BIS listen simultaneously. There
> > > are several issues:
> > >
> > > 1.
> > >
> > >    In struct iso_client_data, although both CIS and BIS related
> > >    elements are defined, they are mutually exclusive. CIS and BIS
> > >    cannot be used at the same time. For example, .bcast must explicitly
> > >    specify whether it is broadcast or unicast.
> > >
> > > 2.
> > >
> > >    The setup_listen_many function also identifies BIS or CIS through
> > >    .bcast.
> > >
> > > Therefore, if we want to add test cases for the coexistence of BIS and
> > > CIS, the current data structure needs to be modified to completely
> > > separate the elements for BIS and CIS.
> > >
> > >
> >
> > I'm not sure if my understanding is fully correct, so I would appreciate
> > any guidance or suggestions.
> >
> > Based on my testing, this patch does fix the issue on my side.
> > Please let me know if there is anything I may have missed or if further
> > changes are needed.
>
> I hope you are paying attention to the mailing list since I did add a
> lot of new code that introduces support for PAST, including new test
> cases for iso-tester, so I don't think asking for a test case for
> having both BIS/CIS together is too much really. Works for me doesn't
> really cut it since we do want to make sure we don't reintroduce the
> problem later, but Im fine merging this now if it doesn't introduce
> any problem existing tests in iso-tester.

You will need to resend it since it is no longer available in patchwork.

> >
> > >>> Do you have any suggestions on how to simulate or test this case more
> > >>> effectively?
> > >>>
> > >>>>> dump sock:
> > >>>>>     sk 000000001977ef51 state 6
> > >>>>>     src 10:a5:62:31:05:cf dst 00:00:00:00:00:00
> > >>>>>     sk 0000000031d28700 state 7
> > >>>>>     src 10:a5:62:31:05:cf dst00:00:00:00:00:00
> > >>>>>     sk 00000000613af00e state 4   # listen sock of bis
> > >>>>>     src 10:a5:62:31:05:cf dst 54:00:00:d4:99:30
> > >>>>>     sk 000000001710468c state 9
> > >>>>>     src 10:a5:62:31:05:cf dst 54:00:00:d4:99:30
> > >>>>>     sk 000000005d97dfde state 4   #listen sock of cis
> > >>>>>     src 10:a5:62:31:05:cf dst 00:00:00:00:00:00
> > >>>>>
> > >>>>> To locate the CIS socket correctly, check both the BT_LISTEN
> > >>>>> state and whether dst addr is BDADDR_ANY.
> > >>>>>
> > >>>>> Link: https://github.com/bluez/bluez/issues/1224
> > >>>>>
> > >>>>> Signed-off-by: Yang Li <yang.li@...ogic.com>
> > >>>>> ---
> > >>>>>    net/bluetooth/iso.c | 9 +++++++--
> > >>>>>    1 file changed, 7 insertions(+), 2 deletions(-)
> > >>>>>
> > >>>>> diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
> > >>>>> index eaffd25570e3..9a4dea03af8c 100644
> > >>>>> --- a/net/bluetooth/iso.c
> > >>>>> +++ b/net/bluetooth/iso.c
> > >>>>> @@ -1919,6 +1919,11 @@ static bool iso_match_pa_sync_flag(struct
> > >>>>> sock *sk, void *data)
> > >>>>>           return test_bit(BT_SK_PA_SYNC, &iso_pi(sk)->flags);
> > >>>>>    }
> > >>>>>
> > >>>>> +static bool iso_match_dst(struct sock *sk, void *data)
> > >>>>> +{
> > >>>>> +       return !bacmp(&iso_pi(sk)->dst, (bdaddr_t *)data);
> > >>>>> +}
> > >>>>> +
> > >>>>>    static void iso_conn_ready(struct iso_conn *conn)
> > >>>>>    {
> > >>>>>           struct sock *parent = NULL;
> > >>>>> @@ -1981,7 +1986,7 @@ static void iso_conn_ready(struct iso_conn
> > >>>>> *conn)
> > >>>>>
> > >>>>>                   if (!parent)
> > >>>>>                           parent = iso_get_sock(&hcon->src,
> > >>>>> BDADDR_ANY,
> > >>>>> -                                             BT_LISTEN, NULL, NULL);
> > >>>>> +                                             BT_LISTEN,
> > >>>>> iso_match_dst, BDADDR_ANY);
> > >>>>>
> > >>>>>                   if (!parent)
> > >>>>>                           return;
> > >>>>> @@ -2220,7 +2225,7 @@ int iso_connect_ind(struct hci_dev *hdev,
> > >>>>> bdaddr_t *bdaddr, __u8 *flags)
> > >>>>>                   }
> > >>>>>           } else {
> > >>>>>                   sk = iso_get_sock(&hdev->bdaddr, BDADDR_ANY,
> > >>>>> -                                 BT_LISTEN, NULL, NULL);
> > >>>>> +                                 BT_LISTEN, iso_match_dst,
> > >>>>> BDADDR_ANY);
> > >>>> Perhaps we should add helper function that wrap the iso_get_sock (e.g.
> > >>>> iso_get_sock_cis and iso_get_sock_bis) to make it clearer what is the
> > >>>> expected socket type, also if the hcon has been set perhaps that
> > >>>> should be matched as well with CIS_LINK/BIS_LINK, or perhaps we
> > >>>> introduce a socket type to differentiate since the use of the address
> > >>>> can make the logic a little confusing when the socket types are mixed
> > >>>> together.
> > >>>>
> > >>>> Now looking at the source code perhaps we can have a separate list for
> > >>>> cis and bis sockets instead of global iso_sk_list (e.g. cis_sk_list
> > >>>> and bis_sk_list), that way we don't need a type and there is no risk
> > >>>> of confusing the sockets since they would never be in the same list.
> > >>>
> > >>> Alright, I will give it a try.
> > >>>
> > >>>>>           }
> > >>>>>
> > >>>>>    done:
> > >>>>>
> > >>>>> ---
> > >>>>> base-commit: 9c533991fe15be60ad9f9a7629c25dbc5b09788d
> > >>>>> change-id: 20250731-bis_cis_coexist-717a442d5c42
> > >>>>>
> > >>>>> Best regards,
> > >>>>> --
> > >>>>> Yang Li <yang.li@...ogic.com>
> > >>>>>
> > >>>>>
> > >>>> --
> > >>>> Luiz Augusto von Dentz
> > >>
> > >>
> > >> --
> > >> Luiz Augusto von Dentz
> >
> >
>
>
> --
> Luiz Augusto von Dentz



-- 
Luiz Augusto von Dentz

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