Hi Pali,
On Thu, Jun 4, 2020 at 4:18 PM Pali Rohár <pali@xxxxxxxxxx> wrote:
>
> When bluetoothd daemon is starting, it prints following error messages:
>
> bluetoothd[19117]: src/profile.c:ext_start_servers() L2CAP server failed for Message Notification: setsockopt(L2CAP_OPTIONS): Invalid argument (22)
> bluetoothd[19117]: src/profile.c:ext_start_servers() L2CAP server failed for Message Access: setsockopt(L2CAP_OPTIONS): Invalid argument (22)
> bluetoothd[19117]: src/profile.c:ext_start_servers() L2CAP server failed for Phone Book Access: setsockopt(L2CAP_OPTIONS): Invalid argument (22)
> bluetoothd[19117]: src/profile.c:ext_start_servers() L2CAP server failed for File Transfer: setsockopt(L2CAP_OPTIONS): Invalid argument (22)
> bluetoothd[19117]: src/profile.c:ext_start_servers() L2CAP server failed for Object Push: setsockopt(L2CAP_OPTIONS): Invalid argument (22)
>
> Result is that Object Push and File Transfer profiles do not work at all.
>
> Debugging set_l2opts() function showed me that src/profile.c calls it with
> L2CAP mode 0x01 (L2CAP_MODE_RETRANS). But kernel bluetooth code in function
> l2cap_sock_setsockopt_old() for L2CAP_OPTIONS option disallows to set L2CAP
> method to 0x01 (L2CAP_MODE_RETRANS) and just returns -EINVAL (22).
>
> These bluetooth profiles have in src/profile.c file defined L2CAP mode to
> BT_IO_MODE_ERTM and not to RETRANS. So it means that BT_IO_MODE_ERTM value
> defined in 'enum BtIOMode' must be incorrect.
>
> Digging into git history, it appears that 'enum BtIOMode' was broken in
> commit f2418bf97d ("btio: Add mode to for Enhanced Credit Mode") which
> basically broke all those Object Push, File Transfer, Phone Book Access,
> Message Access and Message Notification L2CAP profiles. That commit removed
> some values from 'enum BtIOMode' and therefore broke all bluetooth code
> which uses 'enum BtIOMode' for communication with kernel.
>
> This patch fixes 'enum BtIOMode' by reverting back BT_IO_MODE_RETRANS and
> BT_IO_MODE_FLOWCTL modes, so BT_IO_MODE_ERTM has again correct value 0x03.
>
> After applying this patch, Object Push and File Transfer profiles work
> again.
>
> Fixes: f2418bf97d ("btio: Add mode to for Enhanced Credit Mode")
> ---
>
> Hello Luiz, could you please review this patch? As that problematic commit
> f2418bf97d was introduced by you.
>
> I'm curious why nobody else reported this issue about broken Object Push
> and File Transfer profile as it should print those error messages... Or
> maybe error message is visible only in debug build and nobody is using
> Bluetooth File Transfer anymore?
Looks like you are right but, see bellow.
> ---
> btio/btio.h | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/btio/btio.h b/btio/btio.h
> index 23e0ef72b..0d183e3ce 100644
> --- a/btio/btio.h
> +++ b/btio/btio.h
> @@ -68,6 +68,8 @@ typedef enum {
>
> typedef enum {
> BT_IO_MODE_BASIC = 0,
> + BT_IO_MODE_RETRANS,
> + BT_IO_MODE_FLOWCTL,
> BT_IO_MODE_ERTM,
> BT_IO_MODE_STREAMING,
> BT_IO_MODE_LE_FLOWCTL,
> --
> 2.20.1
These modes were never supported by the kernel thus why Ive dropped
them, so might want to translate them to the old L2CAP modes when
set_l2opts is called.
--
Luiz Augusto von Dentz
