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Message-ID: <9f4bc3f2-d66b-42d4-af15-a8b1b1fc696a@nbd.name>
Date: Fri, 26 Apr 2024 11:28:33 +0200
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Subject: Re: [PATCH v3 net-next v3 2/6] net: add support for segmenting TCP
 fraglist GSO packets
To: Eric Dumazet <edumazet@google.com>
Cc: netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
 David Ahern <dsahern@kernel.org>, Jakub Kicinski <kuba@kernel.org>,
 Paolo Abeni <pabeni@redhat.com>, willemdebruijn.kernel@gmail.com,
 linux-kernel@vger.kernel.org
References: <20240426065143.4667-1-nbd@nbd.name>
 <20240426065143.4667-3-nbd@nbd.name>
 <CANn89iJKfgQNNXUL10-7aVZTn+ttqvVNZbnKi6jCdQGwzbFFYQ@mail.gmail.com>
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From: Felix Fietkau <nbd@nbd.name>
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On 26.04.24 09:44, Eric Dumazet wrote:
> On Fri, Apr 26, 2024 at 8:51 AM Felix Fietkau <nbd@nbd.name> wrote:
>>
>> 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.
>>
>> Signed-off-by: Felix Fietkau <nbd@nbd.name>
>> ---
>>  net/ipv4/tcp_offload.c   | 65 ++++++++++++++++++++++++++++++++++++++++
>>  net/ipv6/tcpv6_offload.c |  3 ++
>>  2 files changed, 68 insertions(+)
>>
>> diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
>> index fab0973f995b..c493e95e09a5 100644
>> --- a/net/ipv4/tcp_offload.c
>> +++ b/net/ipv4/tcp_offload.c
>> @@ -28,6 +28,68 @@ static void tcp_gso_tstamp(struct sk_buff *skb, unsigned int ts_seq,
>>         }
>>  }
>>
>> +static void __tcpv4_gso_segment_csum(struct sk_buff *seg,
>> +                                    __be32 *oldip, __be32 *newip,
>> +                                    __be16 *oldport, __be16 *newport)
> 
> 
> Do we really need pointers for newip and 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)
>> +{
>> +       struct sk_buff *seg;
>> +       struct tcphdr *th, *th2;
>> +       struct iphdr *iph, *iph2;
> 
> I would probably add a const qualifier to th and iph

Will do, thanks.

- Felix