From: David Lebrun <david.lebrun@uclouvain.be>
To: Tom Herbert <tom@herbertland.com>
Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>
Subject: Re: [PATCH 1/9] ipv6: implement dataplane support for rthdr type 4 (Segment Routing Header)
Date: Thu, 20 Oct 2016 15:04:59 +0200 [thread overview]
Message-ID: <5808C0FB.2050202@uclouvain.be> (raw)
In-Reply-To: <CALx6S35sU+aw3UvMTknj8SjJP4O=Q-9eVV3OC640Qzces_eE7w@mail.gmail.com>
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On 10/17/2016 07:01 PM, Tom Herbert wrote:
>> > +
>> > + if (skb->ip_summed == CHECKSUM_COMPLETE)
>> > + skb->ip_summed = CHECKSUM_NONE;
>> > +
> Because the packet is being changed? Would it make sense to update the
> checksum complete value based on the changes being made. Consider the
> case that the next hop is local to the host (someone may try to
> implement network virtualization this way).
>
Rethinking about that: even if the next hop is local, I am not sure to
see the benefits of updating the checksum instead of setting
CHECKSUM_NONE. For example, if the next and final hop is local and the
packet carries a TCP payload, tcp_checksum_complete() would force the
recomputation of the checksum anyway (unless ip_summed ==
CHECKSUM_UNNECESSARY).
So I fail to see a path where updating the checksum would be beneficial.
Am I missing something ?
David
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next prev parent reply other threads:[~2016-10-20 13:03 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-17 14:42 [PATCH 0/9] net: add support for IPv6 Segment Routing David Lebrun
2016-10-17 14:42 ` [PATCH 1/9] ipv6: implement dataplane support for rthdr type 4 (Segment Routing Header) David Lebrun
2016-10-17 14:57 ` David Miller
2016-10-17 15:04 ` David Lebrun
2016-10-17 17:01 ` Tom Herbert
2016-10-18 11:43 ` David Lebrun
2016-10-20 13:04 ` David Lebrun [this message]
2016-10-20 15:47 ` Tom Herbert
2016-10-17 17:31 ` Tom Herbert
2016-10-17 14:42 ` [PATCH 2/9] ipv6: sr: add code base for control plane support of SR-IPv6 David Lebrun
2016-10-17 15:00 ` David Miller
2016-10-17 15:06 ` David Lebrun
2016-10-17 15:21 ` David Miller
2016-10-17 17:07 ` Tom Herbert
2016-10-18 11:45 ` David Lebrun
2016-10-17 14:42 ` [PATCH 3/9] ipv6: sr: add support for SRH encapsulation and injection with lwtunnels David Lebrun
2016-10-17 17:17 ` Tom Herbert
2016-10-18 11:47 ` David Lebrun
2016-10-17 14:42 ` [PATCH 4/9] ipv6: sr: add core files for SR HMAC support David Lebrun
2016-10-17 17:24 ` Tom Herbert
2016-10-18 12:07 ` David Lebrun
2016-10-19 13:20 ` zhuyj
2016-10-19 14:43 ` David Laight
2016-10-17 14:43 ` [PATCH 5/9] ipv6: sr: implement API to control SR HMAC structures David Lebrun
2016-10-17 14:43 ` [PATCH 6/9] ipv6: sr: add calls to verify and insert HMAC signatures David Lebrun
2016-10-17 14:43 ` [PATCH 7/9] ipv6: add source address argument for ipv6_push_nfrag_opts David Lebrun
2016-10-17 14:43 ` [PATCH 8/9] ipv6: sr: add support for SRH injection through setsockopt David Lebrun
2016-10-17 14:43 ` [PATCH 9/9] ipv6: sr: add documentation file for per-interface sysctls David Lebrun
2016-10-17 15:09 ` [PATCH 0/9] net: add support for IPv6 Segment Routing David Laight
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