From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cong Wang <cwang@twopensource.com>
Subject: Re: [PATCH net] ipv6: introduce tcp_v6_iif()
Date: Fri, 17 Oct 2014 17:00:31 -0700
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Cc: David Miller <davem@davemloft.net>, netdev <netdev@vger.kernel.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
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On Fri, Oct 17, 2014 at 11:19 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> On Fri, 2014-10-17 at 09:58 -0700, Cong Wang wrote:
>
>> I doubt we still need to store iif in IP6CB() since we have skb->skb_iif,
>> we can probably just make inet6_iif() be like inet_iif() so that IP6CB()->iif
>> can be just removed? Does this make any sense to you?
>>
>
> This makes sense and would gain 4 bytes in skb->cb[], so definitely
> worth it.
>


Hmm, after testing my patch, I found that some IPv6 code (scope_id) calls
inet6_iif() at socket layer too, where skb dst is already dropped. So we can't
simply use skb_dst() for all inet6_iif(). This is also why IPv4 is different.

Therefore, I think your patch is fine at least for net.