Le 06/09/2012 19:03, Vlad Yasevich a écrit :
On 09/06/2012 12:40 PM, Nicolas Dichtel wrote:
Le 06/09/2012 18:04, Vlad Yasevich a écrit :
On 09/06/2012 01:40 PM, Nicolas Dichtel wrote:
dst stored in struct sctp_transport needs to be recalculated when
ipsec policy
are updated. We use flow_cache_genid for that.
For example, if a SCTP connection is established and then an IPsec
policy is
set, the old SCTP flow will not be updated and thus will not use the new
IPsec policy.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx>
why doesn't this need to be done for TCP? What makes SCTP special in
this case?
Tests prove that the pb does not exist with TCP. I made the patch some
times ago, I will look again deeply to find the difference.
TCP appears to cache the flowi and uses that to re-route the packet.
However, re-route still seems predicated on dst_check()...
Yes ... but I don't find the difference. Re-route is not done immediately in
TCP, it takes few seconds.
ip_queue_xmit does an __sk_dst_check() which is essentially what
sctp_transport_dst_check() does. That should determine if the
currently cached
route is valid or not.
The problem is that route will not be invalidated, because dst->check()
has no xfrm path so xfrm_dst_check() will never be called.
Shouldn't the cache be invalidated in this case? If the cache is invalidated,
that should cause a new lookup. If the cache isn't invalidated, then any
established connections that may now be impacted by the policy will not pick it up.
Yes, you're right. If I flush the cache manually (with the sysctl), route are
correctly updated.
I will send a new proposal.
Regards,
Nicolas
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