linux-stable.git/include/net/tcp.h, branch linux-3.1.y

tcp: fix build error if !CONFIG_SYN_COOKIES

2011-09-19T01:48:01+00:00

commit 946cedccbd7387 (tcp: Change possible SYN flooding messages)
added a build error if CONFIG_SYN_COOKIES=n

Reported-by: Markus Trippelsdorf 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

tcp: Change possible SYN flooding messages

2011-09-15T18:49:43+00:00

"Possible SYN flooding on port xxxx " messages can fill logs on servers.

Change logic to log the message only once per listener, and add two new
SNMP counters to track :

TCPReqQFullDoCookies : number of times a SYNCOOKIE was replied to client

TCPReqQFullDrop : number of times a SYN request was dropped because
syncookies were not enabled.

Based on a prior patch from Tom Herbert, and suggestions from David.

Signed-off-by: Eric Dumazet 
CC: Tom Herbert 
Signed-off-by: David S. Miller

tcp: RFC2988bis + taking RTT sample from 3WHS for the passive open side

2011-06-09T00:05:30+00:00

This patch lowers the default initRTO from 3secs to 1sec per
RFC2988bis. It falls back to 3secs if the SYN or SYN-ACK packet
has been retransmitted, AND the TCP timestamp option is not on.

It also adds support to take RTT sample during 3WHS on the passive
open side, just like its active open counterpart, and uses it, if
valid, to seed the initRTO for the data transmission phase.

The patch also resets ssthresh to its initial default at the
beginning of the data transmission phase, and reduces cwnd to 1 if
there has been MORE THAN ONE retransmission during 3WHS per RFC5681.

Signed-off-by: H.K. Jerry Chu 
Signed-off-by: David S. Miller

tcp: Remove debug macro of TCP_CHECK_TIMER

2011-02-20T19:10:14+00:00

Now, TCP_CHECK_TIMER is not used for debuging, it does nothing.
And, it has been there for several years, maybe 6 years.

Remove it to keep code clearer.

Signed-off-by: Shan Wei 
Signed-off-by: David S. Miller

tcp: Add reference to initial CWND ietf draft.

2011-02-06T02:13:45+00:00

Suggested by Alexander Zimmermann

Signed-off-by: David S. Miller

tcp: Increase the initial congestion window to 10.

2011-02-03T04:48:47+00:00

Signed-off-by: David S. Miller 
Acked-by: Nandita Dukkipati

net: change netdev->features to u32

2011-01-24T23:32:47+00:00

Quoting Ben Hutchings: we presumably won't be defining features that
can only be enabled on 64-bit architectures.

Occurences found by `grep -r` on net/, drivers/net, include/

[ Move features and vlan_features next to each other in
  struct netdev, as per Eric Dumazet's suggestion -DaveM ]

Signed-off-by: Michał Mirosław 
Signed-off-by: David S. Miller

TCP: increase default initial receive window.

2010-12-21T05:33:00+00:00

This patch changes the default initial receive window to 10 mss
(defined constant). The default window is limited to the maximum
of 10*1460 and 2*mss (when mss > 1460).

draft-ietf-tcpm-initcwnd-00 is a proposal to the IETF that recommends
increasing TCP's initial congestion window to 10 mss or about 15KB.
Leading up to this proposal were several large-scale live Internet
experiments with an initial congestion window of 10 mss (IW10), where
we showed that the average latency of HTTP responses improved by
approximately 10%. This was accompanied by a slight increase in
retransmission rate (0.5%), most of which is coming from applications
opening multiple simultaneous connections. To understand the extreme
worst case scenarios, and fairness issues (IW10 versus IW3), we further
conducted controlled testbed experiments. We came away finding minimal
negative impact even under low link bandwidths (dial-ups) and small
buffers.  These results are extremely encouraging to adopting IW10.

However, an initial congestion window of 10 mss is useless unless a TCP
receiver advertises an initial receive window of at least 10 mss.
Fortunately, in the large-scale Internet experiments we found that most
widely used operating systems advertised large initial receive windows
of 64KB, allowing us to experiment with a wide range of initial
congestion windows. Linux systems were among the few exceptions that
advertised a small receive window of 6KB. The purpose of this patch is
to fix this shortcoming.

References:
1. A comprehensive list of all IW10 references to date.
http://code.google.com/speed/protocols/tcpm-IW10.html

2. Paper describing results from large-scale Internet experiments with IW10.
http://ccr.sigcomm.org/drupal/?q=node/621

3. Controlled testbed experiments under worst case scenarios and a
fairness study.
http://www.ietf.org/proceedings/79/slides/tcpm-0.pdf

4. Raw test data from testbed experiments (Linux senders/receivers)
with initial congestion and receive windows of both 10 mss.
http://research.csc.ncsu.edu/netsrv/?q=content/iw10

5. Internet-Draft. Increasing TCP's Initial Window.
https://datatracker.ietf.org/doc/draft-ietf-tcpm-initcwnd/

Signed-off-by: Nandita Dukkipati 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: kill unused macros

2010-12-20T05:59:35+00:00

These macros never be used, so remove them.

Signed-off-by: Shan Wei 
Signed-off-by: David S. Miller

tcp: relax tcp_paws_check()

2010-12-16T22:08:34+00:00

Some windows versions have wrong RFC1323 implementations, with SYN and
SYNACKS messages containing zero tcp timestamps.

We relaxed in commit fc1ad92dfc4e363 the passive connection case
(Windows connects to a linux machine), but the reverse case (linux
connects to a Windows machine) has an analogue problem when tsvals from
windows machine are 'negative' (high order bit set) : PAWS triggers and
we drops incoming messages.

Fix this by making zero ts_recent value special, allowing frame to be
processed.

Based on a report and initial patch from Dmitiy Balakin

Bugzilla reference : https://bugzilla.kernel.org/show_bug.cgi?id=24842

Reported-by: dmitriy.balakin@nicneiron.ru
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller