From: Sergei Shtylyov <sergei.shtylyov@cogentembedded•com>
To: Dean Jenkins <Dean_Jenkins@mentor•com>
Cc: davem@davemloft•net, netdev@vger•kernel.org
Subject: Re: [PATCH 2/5] SLIP: Handle error codes from the TTY layer
Date: Wed, 19 Jun 2013 22:00:37 +0400 [thread overview]
Message-ID: <51C1F1C5.6080901@cogentembedded.com> (raw)
In-Reply-To: <1371656071-27754-3-git-send-email-Dean_Jenkins@mentor.com>
Hello Dean.
On 06/19/2013 07:34 PM, Dean Jenkins wrote:
> It appears that SLIP does not handle error codes from the TTY layer.
> This will result in a malfunction because the remaining length of
> data will be corrupted by the negative error code values from the TTY
> layer.
> Therefore, add error code checks in sl_encaps() and sl_encaps_wakeup()
> to prevent the corruption of the sent data length.
> Note that SLIP is connectionless so on TTY error indicate that all data
> was sent. It seems SLIP does not return error codes to the network
> layer.
> Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor•com>
> ---
> drivers/net/slip/slip.c | 26 ++++++++++++++++++++++----
> 1 file changed, 22 insertions(+), 4 deletions(-)
> diff --git a/drivers/net/slip/slip.c b/drivers/net/slip/slip.c
> index a34d6bf..bed819f 100644
> --- a/drivers/net/slip/slip.c
> +++ b/drivers/net/slip/slip.c
[...]
> @@ -404,7 +404,16 @@ static void sl_encaps(struct slip *sl, unsigned char *icp, int len)
> * 14 Oct 1994 Dmitry Gorodchanin.
> */
> set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
> - actual = sl->tty->ops->write(sl->tty, sl->xbuff, count);
> + err = sl->tty->ops->write(sl->tty, sl->xbuff, count);
> +
I don't think empty line is needed here.
> + if (err < 0) {
> + /* error case, say all was sent as connectionless */
> + actual = count;
> + } else {
> + /* good case, err contains the number sent */
> + actual = err;
> + }
> +
> #ifdef SL_CHECK_TRANSMIT
> sl->dev->trans_start = jiffies;
> #endif
[...]
> @@ -438,7 +447,16 @@ static void slip_write_wakeup(struct tty_struct *tty)
> return;
> }
>
> - actual = tty->ops->write(tty, sl->xhead, sl->xleft);
> + err = tty->ops->write(tty, sl->xhead, sl->xleft);
> +
Neither here.
> + if (err < 0) {
> + /* error case, say all was sent as connectionless */
> + actual = sl->xleft;
> + } else {
> + /* good case, err contains the number sent */
> + actual = err;
> + }
> +
WBR, Sergei
next prev parent reply other threads:[~2013-06-19 18:00 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-19 15:34 [PATCH 0/5] SLIP SLIP-Improve robustness to crashing Dean Jenkins
2013-06-19 15:34 ` [PATCH 1/5] Bluetooth: Add RFCOMM TTY write return error codes Dean Jenkins
2013-06-19 18:01 ` Sergei Shtylyov
2013-06-19 15:34 ` [PATCH 2/5] SLIP: Handle error codes from the TTY layer Dean Jenkins
2013-06-19 18:00 ` Sergei Shtylyov [this message]
2013-06-19 15:34 ` [PATCH 3/5] SLIP: Prevent recursion stack overflow and scheduler crash Dean Jenkins
2013-06-19 15:34 ` [PATCH 4/5] SLIP: Add error message for xleft non-zero Dean Jenkins
2013-06-19 15:34 ` [PATCH 5/5] SLIP: Fix transmission segmentation mechanism Dean Jenkins
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