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  1. 12 7月, 2012 2 次提交
  3. 11 7月, 2012 1 次提交
  5. 05 7月, 2012 1 次提交
  7. 23 6月, 2012 1 次提交
  9. 16 6月, 2012 1 次提交
    • D
      ipv6: Handle PMTU in ICMP error handlers. · 81aded24
      由 David S. Miller 提交于 
      One tricky issue on the ipv6 side vs. ipv4 is that the ICMP callouts
to handle the error pass the 32-bit info cookie in network byte order
whereas ipv4 passes it around in host byte order.

Like the ipv4 side, we have two helper functions.  One for when we
have a socket context and one for when we do not.

ip6ip6 tunnels are not handled here, because they handle PMTU events
by essentially relaying another ICMP packet-too-big message back to
the original sender.

This patch allows us to get rid of rt6_do_pmtu_disc().  It handles all
kinds of situations that simply cannot happen when we do the PMTU
update directly using a fully resolved route.

In fact, the "plen == 128" check in ip6_rt_update_pmtu() can very
likely be removed or changed into a BUG_ON() check.  We should never
have a prefixed ipv6 route when we get there.

Another piece of strange history here is that TCP and DCCP, unlike in
ipv4, never invoke the update_pmtu() method from their ICMP error
handlers.  This is incredibly astonishing since this is the context
where we have the most accurate context in which to make a PMTU
update, namely we have a fully connected socket and associated cached
socket route.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      81aded24
  11. 17 5月, 2012 1 次提交
  13. 21 4月, 2012 2 次提交
  15. 20 4月, 2012 1 次提交
  17. 16 4月, 2012 1 次提交
  19. 15 4月, 2012 1 次提交
  21. 04 3月, 2012 2 次提交
  23. 12 1月, 2012 1 次提交
  25. 20 12月, 2011 2 次提交
  27. 17 12月, 2011 1 次提交
  29. 12 12月, 2011 1 次提交
  31. 10 12月, 2011 2 次提交
  33. 07 12月, 2011 2 次提交
  35. 02 12月, 2011 2 次提交
    • D
      dccp: Fix compile warning in probe code. · d984e619
      由 David S. Miller 提交于 
      Commit 1386be55 ("dccp: fix
auto-loading of dccp(_probe)") fixed a bug but created a new
compiler warning:

net/dccp/probe.c: In function ‘dccpprobe_init’:
net/dccp/probe.c:166:2: warning: the omitted middle operand in ?: will always be ‘true’, suggest explicit middle operand [-Wparentheses]

try_then_request_module() is built for situations where the
"existence" test is some lookup function that returns a non-NULL
object on success, and with a reference count of some kind held.

Here we're looking for a success return of zero from the jprobe
registry.

Instead of fighting the way try_then_request_module() works, simply
open code what we want to happen in a local helper function.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d984e619
    • D
      dccp: Evaluate ip_hdr() only once in dccp_v4_route_skb(). · 898f7358
      由 David S. Miller 提交于 
      This also works around a bogus gcc warning generated by an
upcoming patch from Eric Dumazet that rearranges the layout
of struct flowi4.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      898f7358
  37. 23 11月, 2011 1 次提交
  39. 22 11月, 2011 1 次提交
  41. 09 11月, 2011 1 次提交
  43. 04 11月, 2011 1 次提交
  45. 01 11月, 2011 2 次提交
  47. 27 10月, 2011 1 次提交
  49. 07 8月, 2011 1 次提交
    • D
      net: Compute protocol sequence numbers and fragment IDs using MD5. · 6e5714ea
      由 David S. Miller 提交于 
      Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation.  So the periodic
regeneration and 8-bit counter have been removed.  We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.
Reported-by: NDan Kaminsky <dan@doxpara.com>
Tested-by: NWilly Tarreau <w@1wt.eu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6e5714ea
  51. 01 8月, 2011 7 次提交
    • S
      dccp ccid-2: check Ack Ratio when reducing cwnd · d96a9e8d
      由 Samuel Jero 提交于 
      This patch causes CCID-2 to check the Ack Ratio after reducing the congestion
window. If the Ack Ratio is greater than the congestion window, it is
reduced. This prevents timeouts caused by an Ack Ratio larger than the
congestion window.

In this situation, we choose to set the Ack Ratio to half the congestion window
(or one if that's zero) so that if we loose one ack we don't trigger a timeout.

Signed-off-by: Samuel Jero <sj323707@ohio.edu> 
Acked-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
      d96a9e8d
    • S
      dccp ccid-2: increment cwnd correctly · 0ce95dc7
      由 Samuel Jero 提交于 
      This patch fixes an issue where CCID-2 will not increase the congestion
window for numerous RTTs after an idle period, application-limited period,
or a loss once the algorithm is in Congestion Avoidance.

What happens is that, when CCID-2 is in Congestion Avoidance mode, it will
increase hc->tx_packets_acked by one for every packet and will increment cwnd
every cwnd packets. However, if there is now an idle period in the connection,
cwnd will be reduced, possibly below the slow start threshold. This will
cause the connection to go into Slow Start. However, in Slow Start CCID-2
performs this test to increment cwnd every second ack:

	++hc->tx_packets_acked == 2

Unfortunately, this will be incorrect, if cwnd previous to the idle period
was larger than 2 and if tx_packets_acked was close to cwnd. For example:
	cwnd=50  and  tx_packets_acked=45.

In this case, the current code, will increment tx_packets_acked until it
equals two, which will only be once tx_packets_acked (an unsigned 32-bit
integer) overflows.

My fix is simply to change that test for tx_packets_acked greater than or
equal to two in slow start.
Signed-off-by: NSamuel Jero <sj323707@ohio.edu>
Acked-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
      0ce95dc7
    • S
      dccp ccid-2: prevent cwnd > Sequence Window · d346d886
      由 Samuel Jero 提交于 
      Add a check to prevent CCID-2 from increasing the cwnd greater than the
Sequence Window.

When the congestion window becomes bigger than the Sequence Window, CCID-2
will attempt to keep more data in the network than the DCCP Sequence Window
code considers possible. This results in the Sequence Window code issuing
a Sync, thereby inducing needless overhead. Further, if this occurs at the
sender, CCID-2 will never detect the problem because the Acks it receives
will indicate no losses. I have seen this cause a drop of 1/3rd in throughput
for a connection.

Also add code to adjust the Sequence Window to be about 5 times the number of
packets in the network (RFC 4340, 7.5.2) and to adjust the Ack Ratio so that
the remote Sequence Window will hold about 5 times the number of packets in
the network. This allows the congestion window to increase correctly without
being limited by the Sequence Window.
Signed-off-by: NSamuel Jero <sj323707@ohio.edu>
Acked-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
      d346d886
    • G
      dccp ccid-2: use feature-negotiation to report Ack Ratio changes · 31daf039
      由 Gerrit Renker 提交于 
      This uses the new feature-negotiation framework to signal Ack Ratio changes,
as required by RFC 4341, sec. 6.1.2.

That raises some problems with CCID-2, which at the moment can not cope
gracefully with Ack Ratios > 1. Since these issues are not directly related
to feature negotiation, they are marked by a FIXME.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NSamuel Jero <sj323707@ohio.edu>
Acked-by: NIan McDonald <ian.mcdonald@jandi.co.uk>
      31daf039
    • S
      dccp: send Confirm options only once · a6444f42
      由 Samuel Jero 提交于 
      If a connection is in the OPEN state, remove feature negotiation Confirm
options from the list of options after sending them once; as such options
are NOT supposed to be retransmitted and are ONLY supposed to be sent in
response to a Change option (RFC 4340 6.2).
Signed-off-by: NSamuel Jero <sj323707@ohio.edu>
Acked-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
      a6444f42
    • G
      dccp: support for exchanging of NN options in established state 2/2 · 44e6fd9e
      由 Gerrit Renker 提交于 
      This patch adds the receiver side and the (fast-path) activation part for
dynamic changes of non-negotiable (NN) parameters in (PART)OPEN state.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NSamuel Jero <sj323707@ohio.edu>
Acked-by: NIan McDonald <ian.mcdonald@jandi.co.uk>
      44e6fd9e
    • G
      dccp: support for the exchange of NN options in established state 1/2 · d6916f87
      由 Gerrit Renker 提交于 
      In contrast to static feature negotiation at the begin of a connection, this
patch introduces support for exchange of dynamically changing options.

Such an update/exchange is necessary in at least two cases:
 * CCID-2's Ack Ratio (RFC 4341, 6.1.2) which changes during the connection;
 * Sequence Window values that, as per RFC 4340, 7.5.2, should be sent "as
   the connection progresses".

Both are non-negotiable (NN) features, which means that no new capabilities
are negotiated, but rather that changes in known parameters are brought
up-to-date at either end.

Thse characteristics are reflected by the implementation:
 * only NN options can be exchanged after connection setup;
 * an ack is scheduled directly after activation to speed up the update;
 * CCIDs may request changes to an NN feature even if a negotiation for that
   feature is already underway: this is required by CCID-2, where changes in
   cwnd necessitate Ack Ratio changes, such that the previous Ack Ratio (which
   is still being negotiated) would cause irrecoverable RTO timeouts (thanks
   to work by Samuel Jero).	   
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NSamuel Jero <sj323707@ohio.edu>
Acked-by: NIan McDonald <ian.mcdonald@jandi.co.uk>
      d6916f87