Re: [lwip-devel] PPPoS: nb->tot_len in pppos_output_last() is always 0

[Axel Lin]

Hi Sylvain,

2017-06-22 1:47 GMT+08:00 Sylvain Rochet <address@hidden>:
> Hi Axel,
>
> On Mon, Jun 19, 2017 at 06:05:06PM +0800, Axel Lin wrote:
>> In pppos_output_last(),
>> The nb->tot_len is always 0:
>> MIB2_STATS_NETIF_ADD(ppp->netif, ifoutoctets, nb->tot_len);
>>
>> pppos_output_append() increases nb->len but does not update nb->tot_len.
>> Is this a bug?
>
> It obviously is. I wonder if I broke SNMP counters or if it never worked
> at all but I'm too lazy to find out now :-)
>
> PPPoS uses pbuf in its own way and nb->tot_len wasn't necessary. Since
> we are recycling the same pbuf we could use nb->tot_len to keep track of
> the total amount of tx bytes.
>
> By the way, since we are counting bytes past HDLC decoding in
> ppp_input() for ifinoctets I suggest we do the same for the sake of
> consistency for ifoutoctets by only counting actual payload (bytes -fcs
> -escaping -flag).

Maybe the most simply way to do is assigning nb->tot_len to actual
payload length after pbuf_alloc.
I sent below patch for review:
https://savannah.nongnu.org/patch/index.php?9385