Commit 37120f23 authored by Lino Sanfilippo's avatar Lino Sanfilippo Committed by David S. Miller
Browse files

net: dsa: tag_ksz: dont let the hardware process the layer 4 checksum 



If the checksum calculation is offloaded to the network device (e.g due to
NETIF_F_HW_CSUM inherited from the DSA master device), the calculated
layer 4 checksum is incorrect. This is since the DSA tag which is placed
after the layer 4 data is considered as being part of the daa and thus
errorneously included into the checksum calculation.
To avoid this, always calculate the layer 4 checksum in software.

Signed-off-by: default avatarLino Sanfilippo <LinoSanfilippo@gmx.de>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 21cf377a

net/dsa/tag_ksz.c

+9 −0
Original line number Diff line number Diff line
@@ -53,6 +53,9 @@ static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev) 
	u8 *tag;

	u8 *addr;



	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))

		return NULL;



	/* Tag encoding */

	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);

	addr = skb_mac_header(skb);
@@ -114,6 +117,9 @@ static struct sk_buff *ksz9477_xmit(struct sk_buff *skb, 
	u8 *addr;

	u16 val;



	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))

		return NULL;



	/* Tag encoding */

	tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);

	addr = skb_mac_header(skb);
@@ -164,6 +170,9 @@ static struct sk_buff *ksz9893_xmit(struct sk_buff *skb, 
	u8 *addr;

	u8 *tag;



	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))

		return NULL;



	/* Tag encoding */

	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);

	addr = skb_mac_header(skb);