This patch enhances GSO segment checks by verifying the presence
of frag_list and protocol consistency, addressing low throughput
issues on IPv4 servers when used as hotspots
Specifically, it fixes a bug in GSO segmentation when forwarding
GRO packets with frag_list. The function skb_segment_list cannot
correctly process GRO skbs converted by XLAT, because XLAT only
converts the header of the head skb. As a result, skbs in the
frag_list may remain unconverted, leading to protocol
inconsistencies and reduced throughput.
To resolve this, the patch uses skb_segment to handle forwarded
packets converted by XLAT, ensuring that all fragments are
properly converted and segmented.
Signed-off-by: Jibin Zhang <jibin.zhang@mediatek.com>
---
net/ipv4/tcp_offload.c | 3 ++-
net/ipv4/udp_offload.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index fdda18b1abda..162a384a15bb 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -104,7 +104,8 @@ static struct sk_buff *tcp4_gso_segment(struct sk_buff *skb,
if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
return ERR_PTR(-EINVAL);
- if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST) {
+ if ((skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST) && skb_has_frag_list(skb) &&
+ (skb->protocol == skb_shinfo(skb)->frag_list->protocol)) {
struct tcphdr *th = tcp_hdr(skb);
if (skb_pagelen(skb) - th->doff * 4 == skb_shinfo(skb)->gso_size)
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 19d0b5b09ffa..704fb32d10d7 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -512,7 +512,8 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
return NULL;
}
- if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) {
+ if ((skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) && skb_has_frag_list(gso_skb) &&
+ (gso_skb->protocol == skb_shinfo(gso_skb)->frag_list->protocol)) {
/* Detect modified geometry and pass those to skb_segment. */
if (skb_pagelen(gso_skb) - sizeof(*uh) == skb_shinfo(gso_skb)->gso_size)
return __udp_gso_segment_list(gso_skb, features, is_ipv6);
--
2.45.2