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  1. 12 2月, 2011 2 次提交
  3. 11 2月, 2011 3 次提交
    • D
      inet: Create a mechanism for upward inetpeer propagation into routes. · 6431cbc2
      由 David S. Miller 提交于 
      If we didn't have a routing cache, we would not be able to properly
propagate certain kinds of dynamic path attributes, for example
PMTU information and redirects.

The reason is that if we didn't have a routing cache, then there would
be no way to lookup all of the active cached routes hanging off of
sockets, tunnels, IPSEC bundles, etc.

Consider the case where we created a cached route, but no inetpeer
entry existed and also we were not asked to pre-COW the route metrics
and therefore did not force the creation a new inetpeer entry.

If we later get a PMTU message, or a redirect, and store this
information in a new inetpeer entry, there is no way to teach that
cached route about the newly existing inetpeer entry.

The facilities implemented here handle this problem.

First we create a generation ID.  When we create a cached route of any
kind, we remember the generation ID at the time of attachment.  Any
time we force-create an inetpeer entry in response to new path
information, we bump that generation ID.

The dst_ops->check() callback is where the knowledge of this event
is propagated.  If the global generation ID does not equal the one
stored in the cached route, and the cached route has not attached
to an inetpeer yet, we look it up and attach if one is found.  Now
that we've updated the cached route's information, we update the
route's generation ID too.

This clears the way for implementing PMTU and redirects directly in
the inetpeer cache.  There is absolutely no need to consult cached
route information in order to maintain this information.

At this point nothing bumps the inetpeer genids, that comes in the
later changes which handle PMTUs and redirects using inetpeers.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6431cbc2
    • D
      inetpeer: Add redirect and PMTU discovery cached info. · ddd4aa42
      由 David S. Miller 提交于 
      Validity of the cached PMTU information is indicated by it's
expiration value being non-zero, just as per dst->expires.

The scheme we will use is that we will remember the pre-ICMP value
held in the metrics or route entry, and then at expiration time
we will restore that value.

In this way PMTU expiration does not kill off the cached route as is
done currently.

Redirect information is permanent, or at least until another redirect
is received.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ddd4aa42
    • D
      inetpeer: Abstract address representation further. · 7a71ed89
      由 David S. Miller 提交于 
      Future changes will add caching information, and some of
these new elements will be addresses.

Since the family is implicit via the ->daddr.family member,
replicating the family in ever address we store is entirely
redundant.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7a71ed89
  5. 10 2月, 2011 2 次提交
  7. 09 2月, 2011 14 次提交
  9. 08 2月, 2011 19 次提交