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Commit Graph

65889 Commits

Author SHA1 Message Date
Gerrit Renker
e155d76922 [DCCP]: Fix Reset/Sync-Flood Bug
This updates sequence number checking with regard to RFC 4340, 7.5.4.
Missing in the code was an exception for sequence-invalid Reset packets,
which get a Sync acknowledging GSR, instead of (as usual) P.seqno.

This can lead to an oscillating ping-pong flood of Reset packets.

In fact, it has been observed on the wire as follows:

 1. client establishes connection to server;
 2. before server can write to client, client crashes without notifying
    the server (NB: now no longer possible due to ABORT function);
 3. server sends DCCP-Data packet (has no ackno);
 4. client generates Reset "No Connection", seqno=0, increments seqno;
 5. server replies with Sync, using ackno = P.seqno;
 6. client generates Reset "No Connection" with seqno = ackno + 1;
 7. goto (5).

The difference is that now in (5) the server uses GSR.  This causes the
Reset sent by the client in (6) to become sequence-valid, so that in (7)
the vicious circle is broken; the Reset is then enqueued and causes the
socket to enter TIMEWAIT state.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:37 -07:00
Gerrit Renker
cbe1f5f88a [DCCP]: Shorten variable names in dccp_check_seqno
This patch is in part required by the next patch; it

 * replaces 6 instances of `DCCP_SKB_CB(skb)->dccpd_seq' with `seqno';
 * replaces 7 instances of `DCCP_SKB_CB(skb)->dccpd_ack_seq' with `ackno';
 * replaces 1 use of dccp_inc_seqno() by unfolding `ADD48' macro in place.

No changes in algorithm, all changes are text replacement/substitution.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:36 -07:00
Gerrit Renker
3393da8241 [DCCP]: Simplify interface of dccp_sample_rtt
The third parameter of dccp_sample_rtt now becomes useless and is removed.

Also combined the subtraction of the timestamp echo and the elapsed time.
This is safe, since (a) presence of timestamp echo is tested first and (b)
elapsed time is either present and non-zero or it is not set and equals 0
due to the memset in dccp_parse_options.

To avoid measuring option-processing time, the timestamp for measuring the
initial Request/Response RTT sample is taken directly when the function is
called (the Linux implementation always adds a timestamp on the Request,
so there is no loss in doing this).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:35 -07:00
Gerrit Renker
4c70f383e0 [DCCP]: Provide 10s of microsecond timesource
This provides a timesource, conveniently used for DCCP timestamps, which
returns the elapsed time in 10s of microseconds since initialisation.
This makes for a wrap-around time of about 11.9 hours, which should be
sufficient for most applications.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:35 -07:00
Gerrit Renker
aa97efd97a [DCCP]: Reuse ktime_get_real() calls again
This patch reduces the number of timestamps taken in the receive path
for each packet.

The ccid3_hc_tx_update_x() routine is called in
 * the receive path for each CCID3-controlled packet
 * for the nofeedback timer (if no feedback arrives during 4 RTT)

Currently, when there is no loss, each packet gets timestamped twice.
The patch resolves this by recycling the first timestamp taken on packet
reception for RTT sampling.

When the no_feedback_timer() is called, then the timestamp argument is
simply set to NULL - so that ccid3_hc_tx_update_x() takes care of the logic.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:34 -07:00
Michael Wu
e0eb685962 [MAC80211]: rename ieee80211_cfg.h to cfg.h
Might as well rename ieee80211_cfg.h to cfg.h to keep things consistent.

Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:34 -07:00
Johannes Berg
d86ec781ef [MAC80211]: kill vlan_id
Each station has a vlan_id that is useless. Remove it.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:33 -07:00
Johannes Berg
c095df531f [MAC80211]: kill IE parse typedef
The parse result typedef isn't needed.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:33 -07:00
Johannes Berg
fa5fea711f [MAC80211]: rename ieee80211_cfg.c to cfg.c
It's just painful to have the extra ieee80211_ prefix.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:32 -07:00
Johannes Berg
dd1cd4c620 [MAC80211]: print out wiphy name instead of master device
This makes mac80211 print out the wiphy name instead of the
master device name where appropriate.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:32 -07:00
Johannes Berg
9c7d7728ba [MAC80211]: remove tx info sw_retry_attempt member
This is unused.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:31 -07:00
Johannes Berg
693d454dff [MAC80211]: fix warnings introduced by the doc patches
This fixes a warning about NUM_IEEE80211_MODES missing
in a switch statement. Intentionally do not add a default
case so we get warnings at these places if we need to add
new modes.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:30 -07:00
Johannes Berg
6b301cdfad [MAC80211]: yet more documentation
Add more mac80211 documentation.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:30 -07:00
Johannes Berg
c33e3f3bcd [MAC80211]: remove IEEE80211_CONF_SSID_HIDDEN
The IEEE80211_CONF_SSID_HIDDEN setting is not useful for any driver
we have and should be a per-interface setting anyway. Remove it.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:29 -07:00
Johannes Berg
011bfcc4f3 [MAC80211]: remove key threshold stuff
This patch removes the key threshold stuff from mac80211.
I have patches for later that add it as a per-key setting
to nl/cfg80211.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:29 -07:00
Johannes Berg
72abd81b98 [MAC80211]: allow drivers to indicate failed FCS/PLCP checksum
This patch allows drivers to indicate bad FCS/PLCP CRC to the stack and
have the stack drop packets like that except for monitor interfaces.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:28 -07:00
Vladimir Davydov
ac630c2b19 [LIBERTAS]: fix oops on the blackfin architecture
Fixing memory alignment problems on the blackfin architecture (maybe on the
ARM also)

Signed-off-by: Vladimir Davydov <vladimir.davydov@promwad.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:28 -07:00
Vladimir Davydov
f31ce76b78 [LIBERTAS]: fix oops on the blackfin architecture
Reserve two bytes to align pointer to the IP header.

Signed-off-by: Vladimir Davydov <vladimir.davydov@promwad.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:27 -07:00
Ryan Mallon
28de0b36be [LIBERTAS]: fix interrupts in CF driver
The following patch fixes the tx transmit timeout problem, which is
caused by the interrupts being incorrectly check and masked. The patch
moves the interrupt masking code so that interrupts are enabled only
when the driver is registered and only disabled when the driver is
unregistered.

Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:27 -07:00
Ryan Mallon
6f05cbe588 [LIBERTAS]: set dnld_sent correctly for CF parts
Corrects a minor bug with priv->dnld_sent being set incorrectly in
if_cs_host_to_card.

Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:26 -07:00
Larry Finger
1065de1562 [B43LEGACY]: Change the hardware radio enable logic and cleanup code
This change cleans up the radio-related messages in several ways.

(1) The state of the rfkill switch is assumed to be on, rather than
    tested. Now, any user without such a switch will not see any
    messages. For devices with such a switch, a message will be
    logged only if the initial state is off, or if the switch is toggled.
(2) The routine for testing the switch state is no longer inline.
(3) The LED handling routine is simplified.
(4) The "Radio turned off" message that has confused some users has been
    changed to "Radio initialized".

This patch is patterned after a similar change to b43 by Michael Buesch.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:25 -07:00
Larry Finger
42a9174f54 [B43LEGACY]: Support for turning the radio off from software.
This adds support for turning the radio off in software.
That's useful in environments, where you don't want the RF
to radiate any signals, but don't want to bring the interface down.

This patch is based on a similar patch of b43 by Michael Buesch.

Signed-off-by: Larry Finger <larry.finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:25 -07:00
Michael Buesch
fda9abcf1a [B43]: Support for turning the radio off from software.
This adds support for turning the radio off in software.
That's useful in environments, where you don't want the RF
to radiate any signals, but don't want to bring the interface down.

Cc: Larry Finger <larry.finger@lwfinger.net>
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:24 -07:00
Michael Buesch
6a724d68a3 [B43]: Remove the "radio hw enabled" message on startup.
This message is useless. Only report state changes.

Cc: Larry Finger <larry.finger@lwfinger.net>
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:24 -07:00
Michael Buesch
61609bc0e4 [MAC80211]: Add support for setting TX power and radio status
This adds support for disabling the radio and setting the TXpower
through wext.
This also fixes the prism TXpower ioctl (It always overwrote the TXpower
value in ieee80211_hw_config())

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:23 -07:00
Johannes Berg
501d857ec9 [IEEE80211]: Fix softmac lockdep reports.
It seems I was actually able to hit this deadlock, on my quad G5 softmac
locks up more often than not. This fixes it by using an own workqueue
that can safely be flushed under RTNL.

Not sure if the patch is correct with the workqueue naming. And don't
think with the patch it doesn't continually lock up. It still does, just
doesn't invoke lockdep warnings all the time.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:22 -07:00
Michael Buesch
05155c83d1 [B43]: Change loglevel of radio-enable message.
Also cleanup the code a bit and remove the inline.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:21 -07:00
Michael Buesch
6b9bafec66 [SSB]: Sparse fixes.
This fixes all Sparse warnings in SSB.
No semantics change.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:21 -07:00
Michael Buesch
4b402c65a3 [SSB]: Use ioreadX() and iowriteX() for PCI.
On a PCI bus use ioreadX() and iowriteX().
We map the I/O space with pci_iomap(), so we must use the correct
accessor functions, too.
readX() and writeX() are not guaranteed to accept the cookie returned
from pci_iomap() (though, it currently works on most architectures).

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:20 -07:00
Michael Buesch
b85b3b7af5 [B43]: Don't lock irq_lock in debugfs txpower adjust
It's not required and the txpower adjustment must not be in atomic.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:20 -07:00
Andrew Morton
90f4dd0f4b [P54PCI]: terminate pci table
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:19 -07:00
Ulrich Kunitz
ababda03e1 [ZD1211RD]: add USB id for Telegent TG54USB WLAN adapter
Reinhard Speyerer reported at 2007-08-10 a new device.

Here are the information strings.

Product: Telegent TG54USB WLAN Adapter
USB ID: 129b:1666
Chip ID: zd1211 chip 129b:1666 v4330 high 00-01-36 RF2959_RF pa0 -----
FCC ID: N89-UW620Z

Signed-off-by: Ulrich Kunitz <kune@deine-taler.de>
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:18 -07:00
Larry Finger
01449c5a46 [BCM43XX]: Change radio hardware switch status printk from debug to regular
Some distros ship bcm43xx with debugging printout disabled. For those
BCM43xx devices with radio on/off switches, this makes it impossible
to know if the radio is on or off. This patch changes a pair of debug
printk's into ordinary printk's. It also changes the message that
prints when the radio is initialized to the off state as the old message
seems to confuse users.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:18 -07:00
Jesper Juhl
fa46081c50 [ZD1211RW]: Don't needlessly initialize variable to NULL in zd_chip
No need to initialize to NULL when variable is never used before
it's assigned the return value of a kmalloc() call.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:17 -07:00
Christian Borntraeger
e24eb521fb [NET]: note that NETIF_F_LLTX is deprecated
Am Freitag, 21. September 2007 schrieb Herbert Xu:
> Please don't use LLTX in new drivers.  We're trying to get rid
> of it since it's
>
> 1) unnecessary;
> 2) causes problems with AF_PACKET seeing things twice.

I suggest to document that LLTX is deprecated.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:17 -07:00
Zhu Yi
1156b2c689 [IWLWIFI]: remove per-file CFLAGS for IWL define
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:16 -07:00
Jamal Hadi Salim
8236632fb3 [NET_SCHED]: explict hold dev tx lock
For N cpus, with full throttle traffic on all N CPUs, funneling traffic
to the same ethernet device, the devices queue lock is contended by all
N CPUs constantly. The TX lock is only contended by a max of 2 CPUS.
In the current mode of operation, after all the work of entering the
dequeue region, we may endup aborting the path if we are unable to get
the tx lock and go back to contend for the queue lock. As N goes up,
this gets worse.

The changes in this patch result in a small increase in performance
with a 4CPU (2xdual-core) with no irq binding. Both e1000 and tg3
showed similar behavior;

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:15 -07:00
Daniel Lezcano
854d8363f3 [NET]: Dynamically allocate the loopback device, part 2.
Doing this makes loopback.c a better example of how to do a
simple network device, and it removes the special case
single static allocation of a struct net_device, hopefully
making maintenance easier.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-By: Kirill Korotaev <dev@sw.ru>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>
2007-10-10 16:52:15 -07:00
Daniel Lezcano
de3cb747ff [NET]: Dynamically allocate the loopback device, part 1.
This patch replaces all occurences to the static variable
loopback_dev to a pointer loopback_dev. That provides the
mindless, trivial, uninteressting change part for the dynamic
allocation for the loopback.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-By: Kirill Korotaev <dev@sw.ru>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:14 -07:00
Johannes Berg
5568296573 [NL80211]: add netlink interface to cfg80211
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:14 -07:00
David S. Miller
0800f17026 [TCP]: Minor coding style fixup.
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:13 -07:00
Ilpo Järvinen
b76892051c [TCP]: Avoid clearing sacktag hint in trivial situations
There's no reason to clear the sacktag skb hint when small part
of the rexmit queue changes. Account changes (if any) instead when
fragmenting/collapsing. RTO/FRTO do not touch SACKED_ACKED bits so
no need to discard SACK tag hint at all.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:12 -07:00
Ilpo Järvinen
c96fd3d461 [TCP]: Enable SACK enhanced FRTO (RFC4138) by default
Most of the description that follows comes from my mail to
netdev (some editing done):

Main obstacle to FRTO use is its deployment as it has to be on
the sender side where as wireless link is often the receiver's
access link. Take initiative on behalf of unlucky receivers and
enable it by default in future Linux TCP senders. Also IETF
seems to interested in advancing FRTO from experimental [1].

How does FRTO help?
===================

FRTO detects spurious RTOs and avoids a number of unnecessary
retransmissions and a couple of other problems that can arise
due to incorrect guess made at RTO (i.e., that segments were
lost when they actually got delayed which is likely to occur
e.g. in wireless environments with link-layer retransmission).
Though FRTO cannot prevent the first (potentially unnecessary)
retransmission at RTO, I suspect that it won't cost that much
even if you have to pay for each bit (won't be that high
percentage out of all packets after all :-)). However, usually
when you have a spurious RTO, not only the first segment
unnecessarily retransmitted but the *whole window*. It goes like
this: all cumulative ACKs got delayed due to in-order delivery,
then TCP will actually send 1.5*original cwnd worth of data in
the RTO's slow-start when the delayed ACKs arrive (basically the
original cwnd worth of it unnecessarily). In case one is
interested in minimizing unnecessary retransmissions e.g. due to
cost, those rexmissions must never see daylight. Besides, in the
worst case the generated burst overloads the bottleneck buffers
which is likely to significantly delay the further progress of
the flow. In case of ll rexmissions, ACK compression often
occurs at the same time making the burst very "sharp edged" (in
that case TCP often loses most of the segments above high_seq
=> very bad performance too). When FRTO is enabled, those
unnecessary retransmissions are fully avoided except for the
first segment and the cwnd behavior after detected spurious RTO
is determined by the response (one can tune that by sysctl).

Basic version (non-SACK enhanced one), FRTO can fail to detect
spurious RTO as spurious and falls back to conservative
behavior. ACK lossage is much less significant than reordering,
usually the FRTO can detect spurious RTO if at least 2
cumulative ACKs from original window are preserved (excluding
the ACK that advances to high_seq). With SACK-enhanced version,
the detection is quite robust.

FRTO should remove the need to set a high lower bound for the
RTO estimator due to delay spikes that occur relatively common
in some environments (esp. in wireless/cellular ones).

[1] http://www1.ietf.org/mail-archive/web/tcpm/current/msg02862.html

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:12 -07:00
Ilpo Järvinen
cd99889c61 [TCP] FRTO: Update sysctl documentation
Since the SACK enhanced FRTO was added, the code has been
under test numerous times so remove "experimental" claim
from the documentation. Also be a bit more verbose about
the usage.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:11 -07:00
Ilpo Järvinen
009a2e3e4e [TCP] FRTO: Improve interoperability with other undo_marker users
Basically this change enables it, previously other undo_marker
users were left with nothing. Reverse undo_marker logic
completely to get it set right in CA_Loss. On the other hand,
when spurious RTO is detected, clear it. Clearing might be too
heavy for some scenarios but seems safe enough starting point
for now and shouldn't have much effect except in majority of
cases (if in any).

By adding a new FLAG_ we avoid looping through write_queue when
RTO occurs.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:11 -07:00
Ilpo Järvinen
7c46a03e67 [TCP]: Cleanup tcp_tso_acked and tcp_clean_rtx_queue
Implements following cleanups:
- Comment re-placement (CodingStyle)
- tcp_tso_acked() local (wrapper-like) variable removal
  (readability)
- __-types removed (IMHO they make local variables jumpy looking
  and just was space)
- acked -> flag (naming conventions elsewhere in TCP code)
- linebreak adjustments (readability)
- nested if()s combined (reduced indentation)
- clarifying newlines added

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:10 -07:00
Ilpo Järvinen
13fcf850cc [TCP]: Move accounting from tso_acked to clean_rtx_queue
The accounting code is pretty much the same, so it's a shame
we do it in two places.

I'm not too sure if added fully_acked check in MTU probing is
really what we want perhaps the added end_seq could be used in
the after() comparison.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:09 -07:00
Ilpo Järvinen
5af4ec236f [TCP]: clear_all_retrans_hints prefixed by tcp_
In addition, fix its function comment spacing.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
2007-10-10 16:52:09 -07:00
Ilpo Järvinen
91fed7a15c [TCP]: Make fackets_out accurate
Substraction for fackets_out is unconditional when snd_una
advances, thus there's no need to do it inside the loop. Just
make sure correct bounds are honored.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:08 -07:00
Ilpo Järvinen
0dde7b5404 [TCP]: Maintain highest_sack accurately to the highest skb
In general, it should not be necessary to call tcp_fragment for
already SACKed skbs, but it's better to be safe than sorry. And
indeed, it can be called from sacktag when a DSACK arrives or
some ACK (with SACK) reordering occurs (sacktag could be made
to avoid the call in the latter case though I'm not sure if it's
worth of the trouble and added complexity to cover such marginal
case).

The collapse case has return for SACKED_ACKED case earlier, so
just WARN_ON if internal inconsistency is detected for some
reason.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:08 -07:00