[PATCH net-next 03/15] udp: do checksum properly in skb_udp_tunnel_segment
From: Xin Long <lucien.xin@gmail.com>
Date: 2020-09-29 13:49:48
Also in:
linux-sctp
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
This patch fixes two things: When skb->ip_summed == CHECKSUM_PARTIAL, skb_checksum_help() should be called do the checksum, instead of gso_make_checksum(), which is used to do the checksum for current proto after calling skb_segment(), not after the inner proto's gso_segment(). When offload_csum is disabled, the hardware will not do the checksum for the current proto, udp. So instead of calling gso_make_checksum(), it should calculate checksum for udp itself. Signed-off-by: Xin Long <lucien.xin@gmail.com> --- net/ipv4/udp_offload.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index e67a66f..c0b010b 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c@@ -131,14 +131,15 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, uh->check = ~csum_fold(csum_add(partial, (__force __wsum)htonl(len))); - if (skb->encapsulation || !offload_csum) { - uh->check = gso_make_checksum(skb, ~uh->check); - if (uh->check == 0) - uh->check = CSUM_MANGLED_0; - } else { + if (skb->encapsulation) + skb_checksum_help(skb); + + if (offload_csum) { skb->ip_summed = CHECKSUM_PARTIAL; skb->csum_start = skb_transport_header(skb) - skb->head; skb->csum_offset = offsetof(struct udphdr, check); + } else { + uh->check = csum_fold(skb_checksum(skb, udp_offset, len, 0)); } } while ((skb = skb->next)); out:
--
2.1.0