[ovs-dev] [PATCH v7] datapath: Add Stateless TCP Tunneling protocol.

[Jesse Gross]

On Mon, Apr 20, 2015 at 7:33 PM, Pravin Shelar <pshelar at nicira.com> wrote:
> On Mon, Apr 20, 2015 at 5:56 PM, Jesse Gross <jesse at nicira.com> wrote:
>> On Mon, Apr 20, 2015 at 3:54 PM, Pravin Shelar <pshelar at nicira.com> wrote:
>>> On Mon, Apr 20, 2015 at 3:36 PM, Jesse Gross <jesse at nicira.com> wrote:
>>>> On Mon, Apr 20, 2015 at 1:29 PM, Pravin B Shelar <pshelar at nicira.com> wrote:
>>>>> diff --git a/datapath/linux/compat/stt.c b/datapath/linux/compat/stt.c
>>>>> new file mode 100644
>>>>> index 0000000..209bf1a
>>>>> --- /dev/null
>>>>> +++ b/datapath/linux/compat/stt.c
>>>>> +static void update_headers(struct sk_buff *skb, bool head,
>>>>> +                              unsigned int l4_offset, unsigned int hdr_len,
>>>>> +                              bool ipv4, u32 tcp_seq)
>>>> [...]
>>>>> +       skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)) + skb->data_len;
>>>>> +}
>>>>
>>>> I wonder if there are any possible edge cases with resetting truesize
>>>> where the packet is still in someone's transmit queue (such as if we
>>>> are looping back packet). Do we need to orphan it first?
>>>>
>>> ok, I will orphan it in update_headers.
>>
>> Just to clarify - I was mostly just thinking aloud on orphaning it.
>> I'm not totally sure if that is the right thing to do or if this is
>> the right place to do it. I'm not sure what the conceptual
>> justification would be for it and it could potentially result in the
>> sender's buffers not being properly limited. Perhaps not resetting the
>> truesize is the right thing too...
>>
> I have seen warning msg if we do no keep truesize update along with
> changes to skb.

Hmm, interesting, what is the warning? I don't think that I have seen
that before.