From: Ville Tervo <ville.tervo@nokia.com>
To: "ext Gustavo F. Padovan" <padovan@profusion.mobi>
Cc: "Elvis Pfützenreuter" <epx@signove.com>, linux-bluetooth@vger.kernel.org
Subject: Re: Problems with L2CAP: deferred setup and MTU
Date: Thu, 27 Jan 2011 10:03:49 +0200 [thread overview]
Message-ID: <20110127080349.GK874@null> (raw)
In-Reply-To: <20110124190913.GB4300@joana>
Hi Gustavo,
On Mon, Jan 24, 2011 at 05:09:13PM -0200, ext Gustavo F. Padovan wrote:
> Hi Elvis,
>
> * Elvis Pfützenreuter <epx@signove.com> [2011-01-19 17:10:51 -0200]:
>
> > I am currently investigating two problems with L2CAP sockets. Since I am not a kernel guy, I will take an indefinite amount of time to find and fix them; perhaps someone else can find and fix it in 5 minutes, so I think it is worth reporting.
> >
> > First problem is ERTM x MTU, sockets configured with a MTU != 672. Normal sockets exchange MTU in initialization:
> >
> > ./l2test -P 4099 -I 1000 -O 1000
> > l2test[3211]: Connect from 00:1B:DC:0F:C8:A9 [imtu 1000, omtu 1000, flush_to 65535, mode 0, handle 12, class 0x480100]
> >
> > but ERTM sockets seem to ignore the setsockopt() value and exchange the default size (672):
> >
> > ./l2test -P 4099 -I 1000 -O 1000 -X ERTM
> > l2test[3228]: Connect from 00:1B:DC:0F:C8:A9 [imtu 1000, omtu 672, flush_to 65535, mode 3, handle 11, class 0x480100]
> >
> > (obviously the initiator side uses the same parameters)
>
> I pushed I fix for this to bluetooth-next-2.6
>
> Author: Gustavo F. Padovan <padovan@profusion.mobi>
> Date: Mon Jan 24 16:01:43 2011 -0200
>
> Bluetooth: Fix setting of MTU for ERTM and Streaming Mode
>
> The desired MTU should be sent in an Config_Req for all modes.
>
> Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
>
> diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
> index ff191b9..1ee18c6 100644
> --- a/net/bluetooth/l2cap.c
> +++ b/net/bluetooth/l2cap.c
> @@ -2588,11 +2588,11 @@ static int l2cap_build_conf_req(struct sock *sk, void *data)
> }
>
> done:
> + if (pi->imtu != L4CAP_DEFAULT_MTU)
^^^
Probably you noticed this typo already?
> + l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, pi->imtu);
> +
> switch (pi->mode) {
> case L2CAP_MODE_BASIC:
> - if (pi->imtu != L2CAP_DEFAULT_MTU)
> - l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, pi->imtu);
> -
> if (!(pi->conn->feat_mask & L2CAP_FEAT_ERTM) &&
> !(pi->conn->feat_mask & L2CAP_FEAT_STREAMING))
> break;
--
Ville
prev parent reply other threads:[~2011-01-27 8:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-19 19:10 Problems with L2CAP: deferred setup and MTU Elvis Pfützenreuter
2011-01-24 19:09 ` Gustavo F. Padovan
2011-01-27 8:03 ` Ville Tervo [this message]
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