On 10/26/2014 09:52 AM, Guenter Roeck wrote: > Setting skb->protocol to a private protocol type may result in warning > messages such as > e1000e 0000:00:19.0 em1: checksum_partial proto=dada! > > This happens if the L3 protocol is IP or IPv6 and skb->ip_summed is set > to CHECKSUM_PARTIAL. Looking through the code, it appears that changing > skb->protocol for transmitted packets is not necessary and may actually > be harmful. Drop it.
You could emphasize that overriding skb->protocol prevents purposely unmodified (from a DSA perspective) network drivers from properly setting up their transmit checksum offload pointers since they inspect skb->protocol to setup the IPv4 header or IPv6 header pointers. > > Signed-off-by: Guenter Roeck <[email protected]> > --- > v2: > - No change > > net/dsa/tag_dsa.c | 2 -- > net/dsa/tag_edsa.c | 2 -- > net/dsa/tag_trailer.c | 2 -- > 3 files changed, 6 deletions(-) > > diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c > index ce90c8b..2dab270 100644 > --- a/net/dsa/tag_dsa.c > +++ b/net/dsa/tag_dsa.c > @@ -63,8 +63,6 @@ static netdev_tx_t dsa_xmit(struct sk_buff *skb, struct > net_device *dev) > dsa_header[3] = 0x00; > } > > - skb->protocol = htons(ETH_P_DSA); > - > skb->dev = p->parent->dst->master_netdev; > dev_queue_xmit(skb); > > diff --git a/net/dsa/tag_edsa.c b/net/dsa/tag_edsa.c > index 94fcce7..9aeda59 100644 > --- a/net/dsa/tag_edsa.c > +++ b/net/dsa/tag_edsa.c > @@ -76,8 +76,6 @@ static netdev_tx_t edsa_xmit(struct sk_buff *skb, struct > net_device *dev) > edsa_header[7] = 0x00; > } > > - skb->protocol = htons(ETH_P_EDSA); > - > skb->dev = p->parent->dst->master_netdev; > dev_queue_xmit(skb); > > diff --git a/net/dsa/tag_trailer.c b/net/dsa/tag_trailer.c > index 115fdca..e268f9d 100644 > --- a/net/dsa/tag_trailer.c > +++ b/net/dsa/tag_trailer.c > @@ -57,8 +57,6 @@ static netdev_tx_t trailer_xmit(struct sk_buff *skb, struct > net_device *dev) > trailer[2] = 0x10; > trailer[3] = 0x00; > > - nskb->protocol = htons(ETH_P_TRAILER); > - > nskb->dev = p->parent->dst->master_netdev; > dev_queue_xmit(nskb); > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
