linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Lino Sanfilippo <LinoSanfilippo@gmx.de>
To: woojung.huh@microchip.com, olteanv@gmail.com
Cc: UNGLinuxDriver@microchip.com, andrew@lunn.ch,
	vivien.didelot@gmail.com, f.fainelli@gmail.com,
	davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Lino Sanfilippo <LinoSanfilippo@gmx.de>
Subject: [PATCH v2 2/2] net: dsa: tag_ksz: dont let the hardware process the layer 4 checksum
Date: Wed, 21 Jul 2021 23:56:42 +0200	[thread overview]
Message-ID: <20210721215642.19866-3-LinoSanfilippo@gmx.de> (raw)
In-Reply-To: <20210721215642.19866-1-LinoSanfilippo@gmx.de>

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>
---
 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 53565f48934c..a201ccf2435d 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);
-- 
2.32.0


  parent reply	other threads:[~2021-07-21 23:56 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-21 21:56 [PATCH v2 0/2] Fixes for KSZ DSA switch Lino Sanfilippo
2021-07-21 21:56 ` [PATCH v2 1/2] net: dsa: ensure linearized SKBs in case of tail taggers Lino Sanfilippo
2021-07-21 23:35   ` Vladimir Oltean
2021-07-22  3:56     ` Florian Fainelli
2021-07-22 14:14       ` Andrew Lunn
2021-07-22 16:05         ` Florian Fainelli
2021-07-23  7:47         ` Lino Sanfilippo
2021-07-23 12:22           ` Vladimir Oltean
2021-07-23 13:41             ` Lino Sanfilippo
2021-07-21 21:56 ` Lino Sanfilippo [this message]
2021-07-21 23:37   ` [PATCH v2 2/2] net: dsa: tag_ksz: dont let the hardware process the layer 4 checksum Vladimir Oltean
2021-07-22  3:55   ` Florian Fainelli
2021-07-22  6:20 ` [PATCH v2 0/2] Fixes for KSZ DSA switch patchwork-bot+netdevbpf

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210721215642.19866-3-LinoSanfilippo@gmx.de \
    --to=linosanfilippo@gmx.de \
    --cc=UNGLinuxDriver@microchip.com \
    --cc=andrew@lunn.ch \
    --cc=davem@davemloft.net \
    --cc=f.fainelli@gmail.com \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=olteanv@gmail.com \
    --cc=vivien.didelot@gmail.com \
    --cc=woojung.huh@microchip.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).