linux-toradex.git/net/dccp/ccids, branch v3.9.4

net/dccp/ccids: remove depends on CONFIG_EXPERIMENTAL

2013-01-11T19:39:33+00:00

The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

CC: Gerrit Renker 
CC: "David S. Miller" 
Signed-off-by: Kees Cook 
Acked-by: David S. Miller 
Acked-by: Gerrit Renker

dccp: fix info leak via getsockopt(DCCP_SOCKOPT_CCID_TX_INFO)

2012-08-16T04:36:31+00:00

The CCID3 code fails to initialize the trailing padding bytes of struct
tfrc_tx_info added for alignment on 64 bit architectures. It that for
potentially leaks four bytes kernel stack via the getsockopt() syscall.
Add an explicit memset(0) before filling the structure to avoid the
info leak.

Signed-off-by: Mathias Krause 
Cc: Gerrit Renker 
Signed-off-by: David S. Miller

net: Fix (nearly-)kernel-doc comments for various functions

2012-07-11T06:13:45+00:00

Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.

Signed-off-by: Ben Hutchings 
Signed-off-by: David S. Miller

net: cleanup unsigned to unsigned int

2012-04-15T16:44:40+00:00

Use of "unsigned int" is preferred to bare "unsigned" in net tree.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

dccp ccid-3: replace incorrect BUG_ON

2012-03-03T16:02:36+00:00

This replaces an unjustified BUG_ON(), which could get triggered under normal
conditions: X_calc can be 0 when p > 0. X would in this case be set to the
minimum, s/t_mbi. Its replacement avoids t_ipi = 0 (unbounded sending rate).

Thanks to Jordi, Victor and Xavier who reported this.

Signed-off-by: Gerrit Renker 
Acked-by: Ian McDonald

module_param: make bool parameters really bool (net & drivers/net)

2011-12-20T03:27:29+00:00

module_param(bool) used to counter-intuitively take an int.  In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

It's time to remove the int/unsigned int option.  For this version
it'll simply give a warning, but it'll break next kernel version.

(Thanks to Joe Perches for suggesting coccinelle for 0/1 -> true/false).

Cc: "David S. Miller" 
Cc: netdev@vger.kernel.org
Signed-off-by: Rusty Russell 
Signed-off-by: David S. Miller

net: add moduleparam.h for users of module_param/MODULE_PARM_DESC

2011-10-31T23:30:29+00:00

These files were getting access to these two via the implicit
presence of module.h everywhere.  They aren't modules, so they
don't need the full module.h inclusion though.

Signed-off-by: Paul Gortmaker

dccp ccid-2: check Ack Ratio when reducing cwnd

2011-08-01T13:52:36+00:00

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  
Acked-by: Gerrit Renker

dccp ccid-2: increment cwnd correctly

2011-08-01T13:52:36+00:00

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: Samuel Jero 
Acked-by: Gerrit Renker

dccp ccid-2: prevent cwnd > Sequence Window

2011-08-01T13:52:35+00:00

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: Samuel Jero 
Acked-by: Gerrit Renker