[PATCH 6.6.y 1/3] net: add support for segmenting TCP fraglist GSO packets
From: Li hongliang <hidden>
Date: 2026-03-02 06:55:16
Also in:
linux-patches, lkml, stable
Subsystem:
networking [general], networking [tcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
From: Felix Fietkau <nbd@nbd.name> [ Upstream commit bee88cd5bd83d40b8aec4d6cb729378f707f6197 ] Preparation for adding TCP fraglist GRO support. It expects packets to be combined in a similar way as UDP fraglist GSO packets. For IPv4 packets, NAT is handled in the same way as UDP fraglist GSO. Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Felix Fietkau <nbd@nbd.name> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Li hongliang <redacted> --- net/ipv4/tcp_offload.c | 67 ++++++++++++++++++++++++++++++++++++++++ net/ipv6/tcpv6_offload.c | 58 ++++++++++++++++++++++++++++++++++ 2 files changed, 125 insertions(+)
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index f1f723579a49..03b2bf580997 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c@@ -31,6 +31,70 @@ static void tcp_gso_tstamp(struct sk_buff *skb, struct sk_buff *gso_skb, } } +static void __tcpv4_gso_segment_csum(struct sk_buff *seg, + __be32 *oldip, __be32 newip, + __be16 *oldport, __be16 newport) +{ + struct tcphdr *th; + struct iphdr *iph; + + if (*oldip == newip && *oldport == newport) + return; + + th = tcp_hdr(seg); + iph = ip_hdr(seg); + + inet_proto_csum_replace4(&th->check, seg, *oldip, newip, true); + inet_proto_csum_replace2(&th->check, seg, *oldport, newport, false); + *oldport = newport; + + csum_replace4(&iph->check, *oldip, newip); + *oldip = newip; +} + +static struct sk_buff *__tcpv4_gso_segment_list_csum(struct sk_buff *segs) +{ + const struct tcphdr *th; + const struct iphdr *iph; + struct sk_buff *seg; + struct tcphdr *th2; + struct iphdr *iph2; + + seg = segs; + th = tcp_hdr(seg); + iph = ip_hdr(seg); + th2 = tcp_hdr(seg->next); + iph2 = ip_hdr(seg->next); + + if (!(*(const u32 *)&th->source ^ *(const u32 *)&th2->source) && + iph->daddr == iph2->daddr && iph->saddr == iph2->saddr) + return segs; + + while ((seg = seg->next)) { + th2 = tcp_hdr(seg); + iph2 = ip_hdr(seg); + + __tcpv4_gso_segment_csum(seg, + &iph2->saddr, iph->saddr, + &th2->source, th->source); + __tcpv4_gso_segment_csum(seg, + &iph2->daddr, iph->daddr, + &th2->dest, th->dest); + } + + return segs; +} + +static struct sk_buff *__tcp4_gso_segment_list(struct sk_buff *skb, + netdev_features_t features) +{ + skb = skb_segment_list(skb, features, skb_mac_header_len(skb)); + if (IS_ERR(skb)) + return skb; + + return __tcpv4_gso_segment_list_csum(skb); +} + static struct sk_buff *tcp4_gso_segment(struct sk_buff *skb, netdev_features_t features) {
@@ -40,6 +104,9 @@ 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) + return __tcp4_gso_segment_list(skb, features); + if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) { const struct iphdr *iph = ip_hdr(skb); struct tcphdr *th = tcp_hdr(skb);
diff --git a/net/ipv6/tcpv6_offload.c b/net/ipv6/tcpv6_offload.c
index bf0c957e4b5e..503a4338e37a 100644
--- a/net/ipv6/tcpv6_offload.c
+++ b/net/ipv6/tcpv6_offload.c@@ -40,6 +40,61 @@ INDIRECT_CALLABLE_SCOPE int tcp6_gro_complete(struct sk_buff *skb, int thoff) return 0; } +static void __tcpv6_gso_segment_csum(struct sk_buff *seg, + __be16 *oldport, __be16 newport) +{ + struct tcphdr *th; + + if (*oldport == newport) + return; + + th = tcp_hdr(seg); + inet_proto_csum_replace2(&th->check, seg, *oldport, newport, false); + *oldport = newport; +} + +static struct sk_buff *__tcpv6_gso_segment_list_csum(struct sk_buff *segs) +{ + const struct tcphdr *th; + const struct ipv6hdr *iph; + struct sk_buff *seg; + struct tcphdr *th2; + struct ipv6hdr *iph2; + + seg = segs; + th = tcp_hdr(seg); + iph = ipv6_hdr(seg); + th2 = tcp_hdr(seg->next); + iph2 = ipv6_hdr(seg->next); + + if (!(*(const u32 *)&th->source ^ *(const u32 *)&th2->source) && + ipv6_addr_equal(&iph->saddr, &iph2->saddr) && + ipv6_addr_equal(&iph->daddr, &iph2->daddr)) + return segs; + + while ((seg = seg->next)) { + th2 = tcp_hdr(seg); + iph2 = ipv6_hdr(seg); + + iph2->saddr = iph->saddr; + iph2->daddr = iph->daddr; + __tcpv6_gso_segment_csum(seg, &th2->source, th->source); + __tcpv6_gso_segment_csum(seg, &th2->dest, th->dest); + } + + return segs; +} + +static struct sk_buff *__tcp6_gso_segment_list(struct sk_buff *skb, + netdev_features_t features) +{ + skb = skb_segment_list(skb, features, skb_mac_header_len(skb)); + if (IS_ERR(skb)) + return skb; + + return __tcpv6_gso_segment_list_csum(skb); +} + static struct sk_buff *tcp6_gso_segment(struct sk_buff *skb, netdev_features_t features) {
@@ -51,6 +106,9 @@ static struct sk_buff *tcp6_gso_segment(struct sk_buff *skb, if (!pskb_may_pull(skb, sizeof(*th))) return ERR_PTR(-EINVAL); + if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST) + return __tcp6_gso_segment_list(skb, features); + if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) { const struct ipv6hdr *ipv6h = ipv6_hdr(skb); struct tcphdr *th = tcp_hdr(skb);
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2.34.1