Commit daa624d3 authored by Felix Fietkau's avatar Felix Fietkau Committed by Paolo Abeni
Browse files

net: ipv6: fix TCP GSO segmentation with NAT 



When updating the source/destination address, the TCP/UDP checksum needs to
be updated as well.

Fixes: bee88cd5 ("net: add support for segmenting TCP fraglist GSO packets")
Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
Link: https://patch.msgid.link/20250311212530.91519-1-nbd@nbd.name


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 2fc8a346

net/ipv6/tcpv6_offload.c

+15 −6
Original line number Diff line number Diff line
@@ -94,14 +94,23 @@ INDIRECT_CALLABLE_SCOPE int tcp6_gro_complete(struct sk_buff *skb, int thoff) 
}



static void __tcpv6_gso_segment_csum(struct sk_buff *seg,

				     struct in6_addr *oldip,

				     const struct in6_addr *newip,

				     __be16 *oldport, __be16 newport)

{

	struct tcphdr *th;

	struct tcphdr *th = tcp_hdr(seg);



	if (!ipv6_addr_equal(oldip, newip)) {

		inet_proto_csum_replace16(&th->check, seg,

					  oldip->s6_addr32,

					  newip->s6_addr32,

					  true);

		*oldip = *newip;

	}



	if (*oldport == newport)

		return;



	th = tcp_hdr(seg);

	inet_proto_csum_replace2(&th->check, seg, *oldport, newport, false);

	*oldport = newport;

}
@@ -129,10 +138,10 @@ static struct sk_buff *__tcpv6_gso_segment_list_csum(struct sk_buff *segs) 
		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);

		__tcpv6_gso_segment_csum(seg, &iph2->saddr, &iph->saddr,

					 &th2->source, th->source);

		__tcpv6_gso_segment_csum(seg, &iph2->daddr, &iph->daddr,

					 &th2->dest, th->dest);

	}



	return segs;