From 37120f23ac8998c250573ea3247ff77426551f69 Mon Sep 17 00:00:00 2001 From: Lino Sanfilippo <LinoSanfilippo@gmx.de> Date: Wed, 21 Jul 2021 23:56:42 +0200 Subject: [PATCH] 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: Lino Sanfilippo <LinoSanfilippo@gmx.de> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> --- net/dsa/tag_ksz.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c index 53565f48934c0..a201ccf2435d8 100644 --- a/net/dsa/tag_ksz.c +++ b/net/dsa/tag_ksz.c @@ -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); -- GitLab