kernel: fix UDPv6 GSO segmentation with NAT

Fixes issues with rx-gro-list and NAT66

Fixes: https://github.com/openwrt/openwrt/issues/18387
Fixes: https://github.com/openwrt/openwrt/issues/18516
Fixes: https://github.com/openwrt/openwrt/issues/18608
Signed-off-by: Felix Fietkau <nbd@nbd.name>
This commit is contained in:
Felix Fietkau 2025-04-26 19:10:54 +02:00
parent 6b1d0ce88c
commit 5501a502e4

View file

@ -0,0 +1,88 @@
From: Felix Fietkau <nbd@nbd.name>
Date: Sat, 26 Apr 2025 17:18:03 +0200
Subject: [PATCH] net: ipv6: fix UDPv6 GSO segmentation with NAT
If any address or port is changed, update it in all packets and recalculate
checksum.
Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -247,6 +247,62 @@ static struct sk_buff *__udpv4_gso_segme
return segs;
}
+static void __udpv6_gso_segment_csum(struct sk_buff *seg,
+ struct in6_addr *oldip,
+ const struct in6_addr *newip,
+ __be16 *oldport, __be16 newport)
+{
+ struct udphdr *uh = udp_hdr(seg);
+
+ if (ipv6_addr_equal(oldip, newip) && *oldport == newport)
+ return;
+
+ if (uh->check) {
+ inet_proto_csum_replace16(&uh->check, seg, oldip->s6_addr32,
+ newip->s6_addr32, true);
+
+ inet_proto_csum_replace2(&uh->check, seg, *oldport, newport,
+ false);
+ if (!uh->check)
+ uh->check = CSUM_MANGLED_0;
+ }
+
+ *oldip = *newip;
+ *oldport = newport;
+}
+
+static struct sk_buff *__udpv6_gso_segment_list_csum(struct sk_buff *segs)
+{
+ const struct ipv6hdr *iph;
+ const struct udphdr *uh;
+ struct ipv6hdr *iph2;
+ struct sk_buff *seg;
+ struct udphdr *uh2;
+
+ seg = segs;
+ uh = udp_hdr(seg);
+ iph = ipv6_hdr(seg);
+ uh2 = udp_hdr(seg->next);
+ iph2 = ipv6_hdr(seg->next);
+
+ if (!(*(const u32 *)&uh->source ^ *(const u32 *)&uh2->source) &&
+ ipv6_addr_equal(&iph->saddr, &iph2->saddr) &&
+ ipv6_addr_equal(&iph->daddr, &iph2->daddr))
+ return segs;
+
+ while ((seg = seg->next)) {
+ uh2 = udp_hdr(seg);
+ iph2 = ipv6_hdr(seg);
+
+ __udpv6_gso_segment_csum(seg, &iph2->saddr, &iph->saddr,
+ &uh2->source, uh->source);
+ __udpv6_gso_segment_csum(seg, &iph2->daddr, &iph->daddr,
+ &uh2->dest, uh->dest);
+ }
+
+ return segs;
+}
+
static struct sk_buff *__udp_gso_segment_list(struct sk_buff *skb,
netdev_features_t features,
bool is_ipv6)
@@ -259,7 +315,10 @@ static struct sk_buff *__udp_gso_segment
udp_hdr(skb)->len = htons(sizeof(struct udphdr) + mss);
- return is_ipv6 ? skb : __udpv4_gso_segment_list_csum(skb);
+ if (is_ipv6)
+ return __udpv6_gso_segment_list_csum(skb);
+ else
+ return __udpv4_gso_segment_list_csum(skb);
}
struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,