Re: [RFC][PATCH 3/3]ipv6:fix the outgoing interface selection order in udpv6_sendmsg()

[Yang Hongyang <yanghy@cn.fujitsu.com>]

Yang Hongyang wrote:
> David Miller wrote:
>> From: Yang Hongyang <yanghy@cn.fujitsu.com>
>> Date: Wed, 10 Dec 2008 08:42:20 +0800
>>
>>> If outgoing interface is set with SO_BINDTODEVICE and also sticky pktinfo
>>> the outgoing interface is exactly what SO_BINDTODEVICE set,because in my
>>> first patch,when set sticy pktinfo,outgoing interface set by SO_BINDTODEVICE
>>> is checked:
>>>
>>> +		if(sk->sk_bound_dev_if && pkt.ipi6_ifindex != sk->sk_bound_dev_if)
>>> +			goto e_inval;
>>>
>> You may be checking this, but these two values can become out of sync
>> if the application next makes a SO_BINDTODEVICE setsockopt() call to
>> change the index setting.
>>
>> Nothing makes sure the sticky ipv6 socket information is updated
>> if that happens.  And the most obvious ways to handle that are
>> very ugly, doing some kind of call into ipv6 from the generic
>> socket SO_BINDTODEVICE setsockopt() handler.
>>
>>
> 
> Hum..can we just ignore the sync of the sticky option and the SO_BINDTODEVICE,
> when send a message,first check sk_bound_dev_if,If it is specified,use it,otherwise
> use sticky option?This was what i ment. and in my patch ,the outgoing interface 
> specified by sticky options will be overrided by the interface specified by 
> SO_BINDTODEVICE.

If this is the solution, i'll post a updated patch.

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