From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gao feng <gaofeng@cn.fujitsu.com>
Subject: Re: [PATCH v5] ipv6: Fix problem with expired dst cache
Date: Mon, 19 Mar 2012 08:49:51 +0800
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References: <1330064404-24763-1-git-send-email-gaofeng@cn.fujitsu.com> <1330931762-1466-1-git-send-email-gaofeng@cn.fujitsu.com> <20120316.223353.988595838790067214.davem@davemloft.net>
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To: David Miller <davem@davemloft.net>
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=E4=BA=8E 2012=E5=B9=B403=E6=9C=8817=E6=97=A5 13:33, David Miller =E5=86=
=99=E9=81=93:
> From: Gao feng <gaofeng@cn.fujitsu.com>
> Date: Mon, 5 Mar 2012 15:16:02 +0800
>=20
>> If the ipv6 dst cache which copy from the dst generated by ICMPV6 RA=
 packet.
>> this dst cache will not check expire because it has no RTF_EXPIRES f=
lag.
>> So this dst cache will always be used until the dst gc run.
>>
>> Change the struct dst_entry,add a union contains new pointer from an=
d expires.
>> When rt6_info.rt6i_flags has no RTF_EXPIRES flag,the dst.expires has=
 no use.
>> we can use this field to point to where the dst cache copy from.
>> The dst.from is only used in IPV6.
>>
>> In func rt6_check_expired check if rt6_info.dst.from is expired.
>>
>> In func ip6_rt_copy only set dst.from when the ort has flag RTF_ADDR=
CONF
>> and RTF_DEFAULT.then hold the ort.
>>
>> In func ip6_dst_destroy release the ort.
>>
>> Add some functions to operate the RTF_EXPIRES flag and expires(from)=
 together.
>> and change the code to use these new adding functions.
>>
>> Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
>=20
> I see some unprotected access to dst.expires in the router discovery
> code in net/ipv6/ndisc.c, doesn't that need to be updated?
>=20
> There are probably some more similar cases elsewhere in the ipv6 code
> too.
>=20

Hi David

I only search the RTF_EXPIRES flag and forget the expires.I will do thi=
s.

BUT what confuse me is that, in func ip6_rt_copy should we do rt6_set_f=
rom in any case
or only when the ort has flag RTF_ADDRCONF and RTF_DEFAULT?

thanks.