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From: "Gustavo F. Padovan" <gustavo@padovan.org>
To: Mat Martineau <mathewm@codeaurora.org>
Cc: linux-bluetooth@vger.kernel.org, marcel@holtmann.org,
	rshaffer@codeaurora.org, linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH 4/9] Bluetooth:  Fix endianness issue with L2CAP MPS configuration.
Date: Thu, 5 Aug 2010 01:00:19 -0300	[thread overview]
Message-ID: <20100805040018.GG7870@vigoh> (raw)
In-Reply-To: <1280962146-22604-5-git-send-email-mathewm@codeaurora.org>

Hi Mat,

* Mat Martineau <mathewm@codeaurora.org> [2010-08-04 15:49:01 -0700]:

> Incoming configuration values must be converted to native CPU order
> before use.  This fixes a bug where a little-endian MPS value is
> compared to a native CPU value.  On big-endian processors, this
> can cause ERTM and streaming mode segmentation to produce PDUs
> that are larger than the remote stack is expecting, or that would
> produce fragmented skbs that the current FCS code cannot handle.
> 
> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
> ---
>  net/bluetooth/l2cap.c |    9 ++++-----
>  1 files changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
> index 920a53f..8cf9569 100644
> --- a/net/bluetooth/l2cap.c
> +++ b/net/bluetooth/l2cap.c
> @@ -2708,10 +2708,10 @@ done:
>  		case L2CAP_MODE_ERTM:
>  			pi->remote_tx_win = rfc.txwin_size;
>  			pi->remote_max_tx = rfc.max_transmit;
> -			if (rfc.max_pdu_size > pi->conn->mtu - 10)
> -				rfc.max_pdu_size = le16_to_cpu(pi->conn->mtu - 10);
>  
>  			pi->remote_mps = le16_to_cpu(rfc.max_pdu_size);
> +			if (pi->remote_mps > pi->conn->mtu - 10)
> +				pi->remote_mps = pi->conn->mtu - 10;


What happened with thte "rfc.max_pdu_size =" attribution. We have the
send the value to through the RFC option. So what I do propose here is:

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 0f34e12..11d4405 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -2705,7 +2705,7 @@ done:
                case L2CAP_MODE_ERTM:
                        pi->remote_tx_win = rfc.txwin_size;
                        pi->remote_max_tx = rfc.max_transmit;
-                       if (rfc.max_pdu_size > pi->conn->mtu - 10)
+                       if (le16_to_cpu(rfc.max_pdu_size) > pi->conn->mtu - 10)
                                rfc.max_pdu_size = le16_to_cpu(pi->conn->mtu - 10);

                        pi->remote_mps = le16_to_cpu(rfc.max_pdu_size);
@@ -2723,7 +2723,7 @@ done:
                        break;

                case L2CAP_MODE_STREAMING:
-                       if (rfc.max_pdu_size > pi->conn->mtu - 10)
+                       if (le16_to_cpu(rfc.max_pdu_size) > pi->conn->mtu - 10)
                                rfc.max_pdu_size = le16_to_cpu(pi->conn->mtu - 10);

                        pi->remote_mps = le16_to_cpu(rfc.max_pdu_size);



>  
>  			rfc.retrans_timeout =
>  				le16_to_cpu(L2CAP_DEFAULT_RETRANS_TO);
> @@ -2726,10 +2726,9 @@ done:
>  			break;
>  
>  		case L2CAP_MODE_STREAMING:
> -			if (rfc.max_pdu_size > pi->conn->mtu - 10)
> -				rfc.max_pdu_size = le16_to_cpu(pi->conn->mtu - 10);
> -
>  			pi->remote_mps = le16_to_cpu(rfc.max_pdu_size);
> +			if (pi->remote_mps > pi->conn->mtu - 10)
> +				pi->remote_mps = pi->conn->mtu - 10;
>  
>  			pi->conf_state |= L2CAP_CONF_MODE_DONE;

-- 
Gustavo F. Padovan
http://padovan.org

  reply	other threads:[~2010-08-05  4:00 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-04 22:48 [PATCH v2 0/9] Bluetooth: L2CAP updates for PSM validation and ERTM Mat Martineau
2010-08-04 22:48 ` [PATCH 1/9] Bluetooth: Only enable for L2CAP FCS for ERTM or streaming Mat Martineau
2010-08-05  3:32   ` Gustavo F. Padovan
2010-08-05 16:27     ` Mat Martineau
2010-08-05  3:38   ` Gustavo F. Padovan
2010-08-04 22:48 ` [PATCH 2/9] Bluetooth: Change default ERTM retransmit timeout Mat Martineau
2010-08-05  3:29   ` Gustavo F. Padovan
2010-08-05 15:53     ` Mat Martineau
2010-08-04 22:49 ` [PATCH 3/9] Bluetooth: Validate PSM values in calls to connect() and bind() Mat Martineau
2010-08-04 22:49 ` [PATCH 4/9] Bluetooth: Fix endianness issue with L2CAP MPS configuration Mat Martineau
2010-08-05  4:00   ` Gustavo F. Padovan [this message]
2010-08-05 16:50     ` Mat Martineau
2010-08-04 22:49 ` [PATCH 5/9] Bluetooth: Fix incorrect setting of remote_tx_win for L2CAP ERTM Mat Martineau
2010-08-05  4:20   ` Gustavo F. Padovan
2010-08-05 16:54     ` Mat Martineau
2010-08-04 22:49 ` [PATCH 6/9] Bluetooth: Add common code for stream-oriented recvmsg() Mat Martineau
2010-08-04 22:49 ` [PATCH 7/9] Bluetooth: Use common SOCK_STREAM receive code in RFCOMM Mat Martineau
2010-08-04 22:49 ` [PATCH 8/9] Bluetooth: Use a stream-oriented recvmsg with SOCK_STREAM L2CAP sockets Mat Martineau
2010-08-04 22:49 ` [PATCH 9/9] Bluetooth: Use 3-DH5 payload size for default ERTM max PDU size Mat Martineau
  -- strict thread matches above, loose matches on Subject: below --
2010-08-05 22:54 [PATCH v3 0/9] Bluetooth: L2CAP updates for PSM validation and ERTM Mat Martineau
2010-08-05 22:54 ` [PATCH 4/9] Bluetooth: Fix endianness issue with L2CAP MPS configuration Mat Martineau
2010-08-09  8:36   ` Marcel Holtmann

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