[PATCH net-next v4 01/12] net/sched: act_csum: don't mangle UDP tunnel GSO packets

[Alice Mikityanska <alice.kernel@fastmail.im>]

From: Alice Mikityanska <alice@isovalent.com>

Similar to commit add641e7dee3 ("sched: act_csum: don't mangle TCP and
UDP GSO packets"), UDP tunnel GSO packets going through act_csum
shouldn't have their checksum calculated at this point, because it will
be done after segmentation. Setting the checksum in act_csum modifies
skb->ip_summed and prevents inner IP csum offload from kicking in,
resulting in a packet with a bad checksum.

Add UDP tunnel GSO packets to the exceptions, and also add UDP GSO
(SKB_GSO_UDP_L4), as the same logic as in the commit mentioned above
applies to UDP GSO too.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
---
 net/sched/act_csum.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c
index a9e4635d899e..078d3a27130b 100644
--- a/net/sched/act_csum.c
+++ b/net/sched/act_csum.c
@@ -259,7 +259,9 @@ static int tcf_csum_ipv4_udp(struct sk_buff *skb, unsigned int ihl,
 	const struct iphdr *iph;
 	u16 ul;
 
-	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
+	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type &
+	    (SKB_GSO_UDP | SKB_GSO_UDP_L4 |
+	     SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM))
 		return 1;
 
 	/*
@@ -315,7 +317,9 @@ static int tcf_csum_ipv6_udp(struct sk_buff *skb, unsigned int ihl,
 	const struct ipv6hdr *ip6h;
 	u16 ul;
 
-	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
+	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type &
+	    (SKB_GSO_UDP | SKB_GSO_UDP_L4 |
+	     SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM))
 		return 1;
 
 	/*
-- 
2.54.0