[PATCH net-next v2 09/12] udp: Set length in UDP header to 0 for big GSO packets

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

From: Alice Mikityanska <alice@isovalent.com>

skb->len may be bigger than 65535 in UDP-based tunnels that have BIG TCP
enabled. If GSO aggregates packets that large, set the length in the UDP
header to 0, so that tcpdump can print such packets properly (treating
them as RFC 2675 jumbograms). Later in the pipeline, __udp_gso_segment
will set uh->len to the size of individual packets.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 net/ipv4/udp_tunnel_core.c | 2 +-
 net/ipv6/ip6_udp_tunnel.c  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/udp_tunnel_core.c b/net/ipv4/udp_tunnel_core.c
index 18f789d9383e..8c586dc08f3b 100644
--- a/net/ipv4/udp_tunnel_core.c
+++ b/net/ipv4/udp_tunnel_core.c
@@ -184,7 +184,7 @@ void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb
 
 	uh->dest = dst_port;
 	uh->source = src_port;
-	udp_set_len_short(uh, skb->len);
+	udp_set_len(uh, skb->len);
 
 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 
diff --git a/net/ipv6/ip6_udp_tunnel.c b/net/ipv6/ip6_udp_tunnel.c
index 26b140fea7b7..b7810736d1c6 100644
--- a/net/ipv6/ip6_udp_tunnel.c
+++ b/net/ipv6/ip6_udp_tunnel.c
@@ -93,7 +93,7 @@ void udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
 	uh->dest = dst_port;
 	uh->source = src_port;
 
-	udp_set_len_short(uh, skb->len);
+	udp_set_len(uh, skb->len);
 
 	skb_dst_set(skb, dst);
 
-- 
2.52.0