On Mon, Jun 18, 2018 at 8:18 PM Eric Dumazet <eric.duma...@gmail.com> wrote:
>
>
>
> On 06/18/2018 10:54 AM, Andreas Schwab wrote:
> > On Jun 17 2018, Eric Dumazet <eric.duma...@gmail.com> wrote:
> >
> >> Oh this is silly, please try :
> >>
> >> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> >> index
> >> c642304f178ce0a4e1358d59e45032a39f76fb3f..54dd9c18ecad817812898d6f335e1794a07dabbe
> >> 100644
> >> --- a/net/core/skbuff.c
> >> +++ b/net/core/skbuff.c
> >> @@ -1845,10 +1845,9 @@ EXPORT_SYMBOL(___pskb_trim);
> >> int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len)
> >> {
> >> if (skb->ip_summed == CHECKSUM_COMPLETE) {
> >> - int delta = skb->len - len;
> >> + __wsum csumdiff = skb_checksum(skb, len, skb->len - len,
> >> 0);
> >>
> >> - skb->csum = csum_sub(skb->csum,
> >> - skb_checksum(skb, len, delta, 0));
> >> + skb->csum = csum_block_sub(skb->csum, csumdiff, len);
> >> }
> >> return __pskb_trim(skb, len);
> >> }
> >
> > That doesn't help either.
> >
> > Andreas.
> >
>
> Then maybe NIC provided csum is not correct.
>
> It does not compute a checksum on all the frame, but part of it.
>
> You could use this patch to double check.
>
> diff --git a/drivers/net/ethernet/sun/sungem.c
> b/drivers/net/ethernet/sun/sungem.c
> index
> 7a16d40a72d13cf1d522e8a3a396c826fe76f9b9..277859ea73e35271a10b02011120fca248ec8e71
> 100644
> --- a/drivers/net/ethernet/sun/sungem.c
> +++ b/drivers/net/ethernet/sun/sungem.c
> @@ -857,6 +857,11 @@ static int gem_rx(struct gem *gp, int work_to_do)
>
> csum = (__force __sum16)htons((status & RXDCTRL_TCPCSUM) ^
> 0xffff);
> skb->csum = csum_unfold(csum);
> + {
> + __wsum rsum = csum_partial(skb->data + ETH_HLEN, len -
> ETH_HLEN, 0);
> + if (csum != csum_fold(rsum))
> + pr_err_ratelimited("sungem wrong csum : %x/%x, len %u
> bytes\n", csum, csum_fold(rsum), len);
> + }
> skb->ip_summed = CHECKSUM_COMPLETE;
> skb->protocol = eth_type_trans(skb, gp->dev);
>
>
Here is what I get on my side
[ 53.628847] sungem: sungem wrong csum : 4e04/f97, len 64 bytes
[ 53.667063] sungem: sungem wrong csum : eea8/6eec, len 149 bytes
[ 58.648952] sungem: sungem wrong csum : 2095/3d06, len 64 bytes
[ 58.669414] sungem: sungem wrong csum : 5245/b50, len 149 bytes
[ 63.674451] sungem: sungem wrong csum : 2d8/5abd, len 149 bytes
[ 68.678233] sungem: sungem wrong csum : b8fc/a498, len 149 bytes
[ 73.685771] sungem: sungem wrong csum : 374/5a21, len 149 bytes
[ 78.689089] sungem: sungem wrong csum : d81/5014, len 149 bytes
[ 83.683261] sungem: sungem wrong csum : 4e04/f97, len 64 bytes
[ 83.690193] sungem: sungem wrong csum : c2f7/9a9d, len 149 bytes
[ 88.692511] sungem: sungem wrong csum : f4d8/68bc, len 149 bytes
[ 93.699915] sungem: sungem wrong csum : 1370/4a25, len 149 bytes
[ 98.703136] sungem: sungem wrong csum : e1b5/7bdf, len 149 bytes
[ 103.704230] sungem: sungem wrong csum : 5321/a74, len 149 bytes
[ 108.688912] sungem: sungem wrong csum : 2095/3d06, len 64 bytes
[ 108.706559] sungem: sungem wrong csum : ddbc/7fd8, len 149 bytes
[ 113.713189] sungem: sungem wrong csum : 5a65/330, len 149 bytes
[ 113.891697] sungem: sungem wrong csum : 4e04/f97, len 64 bytes
[ 118.717151] sungem: sungem wrong csum : f7c8/65cc, len 149 bytes
[ 123.722680] sungem: sungem wrong csum : 3d7a/201b, len 149 bytes
[ 128.726524] sungem: sungem wrong csum : c8fd/9497, len 149 bytes
[ 133.732045] sungem: sungem wrong csum : de0d/7f87, len 149 bytes
[ 135.529163] sungem: sungem wrong csum : 3089/b6dd, len 96 bytes
[ 135.529208] eth0: hw csum failure
[ 135.529220] CPU: 0 PID: 0 Comm: swapper Not tainted 4.17.0+ #7
[ 135.529226] Call Trace:
[ 135.529243] [dffedbe0] [c069ddac]
__skb_checksum_complete+0xf0/0x108 (unreliable)
>
>
>
