On Wed, Oct 28, 2020 at 6:01 PM Xie He <xie.he.0...@gmail.com> wrote:
>
> When the fr_rx function drops a received frame (because the protocol type
> is not supported, or because the PVC virtual device that corresponds to
> the DLCI number and the protocol type doesn't exist), the function frees
> the skb and returns.
>
> The code for freeing the skb and returning is repeated several times, this
> patch uses "goto rx_drop" to replace them so that the code looks cleaner.
>
> Also add code to increase the stats.rx_dropped count whenever we drop a
> frame.
>
> Cc: Krzysztof Halasa <k...@pm.waw.pl>
> Signed-off-by: Xie He <xie.he.0...@gmail.com>
> ---
> drivers/net/wan/hdlc_fr.c | 16 +++++++---------
> 1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c
> index 409e5a7ad8e2..c774eff44534 100644
> --- a/drivers/net/wan/hdlc_fr.c
> +++ b/drivers/net/wan/hdlc_fr.c
> @@ -904,8 +904,7 @@ static int fr_rx(struct sk_buff *skb)
> netdev_info(frad, "No PVC for received frame's DLCI %d\n",
> dlci);
> #endif
> - dev_kfree_skb_any(skb);
> - return NET_RX_DROP;
> + goto rx_drop;
> }
>
> if (pvc->state.fecn != fh->fecn) {
> @@ -963,14 +962,12 @@ static int fr_rx(struct sk_buff *skb)
> default:
> netdev_info(frad, "Unsupported protocol, OUI=%x
> PID=%x\n",
> oui, pid);
> - dev_kfree_skb_any(skb);
> - return NET_RX_DROP;
> + goto rx_drop;
> }
> } else {
> netdev_info(frad, "Unsupported protocol, NLPID=%x
> length=%i\n",
> data[3], skb->len);
> - dev_kfree_skb_any(skb);
> - return NET_RX_DROP;
> + goto rx_drop;
> }
>
> if (dev) {
> @@ -982,12 +979,13 @@ static int fr_rx(struct sk_buff *skb)
> netif_rx(skb);
> return NET_RX_SUCCESS;
> } else {
> - dev_kfree_skb_any(skb);
> - return NET_RX_DROP;
> + goto rx_drop;
> }
>
> - rx_error:
> +rx_error:
> frad->stats.rx_errors++; /* Mark error */
> +rx_drop:
> + frad->stats.rx_dropped++;
> dev_kfree_skb_any(skb);
> return NET_RX_DROP;
This does change rx_dropped count on errors. Not sure how important
that is. But perhaps good to call out in the commit explicitly if it's
intentional.
