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Commit Graph

498 Commits

Author SHA1 Message Date
David S. Miller
2397849baa [PATCH] tcp: Cache inetpeer in timewait socket, and only when necessary.
Since it's guarenteed that we will access the inetpeer if we're trying
to do timewait recycling and TCP options were enabled on the
connection, just cache the peer in the timewait socket.

In the future, inetpeer lookups will be context dependent (per routing
realm), and this helps facilitate that as well.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-09 14:56:12 -07:00
David S. Miller
4670fd819e tcp: Get rid of inetpeer special cases.
The get_peer method TCP uses is full of special cases that make no
sense accommodating, and it also gets in the way of doing more
reasonable things here.

First of all, if the socket doesn't have a usable cached route, there
is no sense in trying to optimize timewait recycling.

Likewise for the case where we have IP options, such as SRR enabled,
that make the IP header destination address (and thus the destination
address of the route key) differ from that of the connection's
destination address.

Just return a NULL peer in these cases, and thus we're also able to
get rid of the clumsy inetpeer release logic.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-09 01:25:47 -07:00
Eric Dumazet
a2a385d627 tcp: bool conversions
bool conversions where possible.

__inline__ -> inline

space cleanups

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-17 14:59:59 -04:00
Pavel Emelyanov
292e8d8c85 tcp: Move rcvq sending to tcp_input.c
It actually works on the input queue and will use its read mem
routines, thus it's better to have in in the tcp_input.c file.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-10 23:24:35 -04:00
Eric Dumazet
bd14b1b2e2 tcp: be more strict before accepting ECN negociation
It appears some networks play bad games with the two bits reserved for
ECN. This can trigger false congestion notifications and very slow
transferts.

Since RFC 3168 (6.1.1) forbids SYN packets to carry CT bits, we can
disable TCP ECN negociation if it happens we receive mangled CT bits in
the SYN packet.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Perry Lorier <perryl@google.com>
Cc: Matt Mathis <mattmathis@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Wilmer van der Gaast <wilmer@google.com>
Cc: Ankur Jain <jankur@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Dave Täht <dave.taht@bufferbloat.net>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-04 12:05:27 -04:00
Eric Dumazet
b081f85c29 net: implement tcp coalescing in tcp_queue_rcv()
Extend tcp coalescing implementing it from tcp_queue_rcv(), the main
receiver function when application is not blocked in recvmsg().

Function tcp_queue_rcv() is moved a bit to allow its call from
tcp_data_queue()

This gives good results especially if GRO could not kick, and if skb
head is a fragment.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-02 21:11:11 -04:00
Yuchung Cheng
750ea2bafa tcp: early retransmit: delayed fast retransmit
Implementing the advanced early retransmit (sysctl_tcp_early_retrans==2).
Delays the fast retransmit by an interval of RTT/4. We borrow the
RTO timer to implement the delay. If we receive another ACK or send
a new packet, the timer is cancelled and restored to original RTO
value offset by time elapsed.  When the delayed-ER timer fires,
we enter fast recovery and perform fast retransmit.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-02 20:56:10 -04:00
Yuchung Cheng
eed530b6c6 tcp: early retransmit
This patch implements RFC 5827 early retransmit (ER) for TCP.
It reduces DUPACK threshold (dupthresh) if outstanding packets are
less than 4 to recover losses by fast recovery instead of timeout.

While the algorithm is simple, small but frequent network reordering
makes this feature dangerous: the connection repeatedly enter
false recovery and degrade performance. Therefore we implement
a mitigation suggested in the appendix of the RFC that delays
entering fast recovery by a small interval, i.e., RTT/4. Currently
ER is conservative and is disabled for the rest of the connection
after the first reordering event. A large scale web server
experiment on the performance impact of ER is summarized in
section 6 of the paper "Proportional Rate Reduction for TCP”,
IMC 2011. http://conferences.sigcomm.org/imc/2011/docs/p155.pdf

Note that Linux has a similar feature called THIN_DUPACK. The
differences are THIN_DUPACK do not mitigate reorderings and is only
used after slow start. Currently ER is disabled if THIN_DUPACK is
enabled. I would be happy to merge THIN_DUPACK feature with ER if
people think it's a good idea.

ER is enabled by sysctl_tcp_early_retrans:
  0: Disables ER

  1: Reduce dupthresh to packets_out - 1 when outstanding packets < 4.

  2: (Default) reduce dupthresh like mode 1. In addition, delay
     entering fast recovery by RTT/4.

Note: mode 2 is implemented in the third part of this patch series.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-02 20:56:10 -04:00
Eric Dumazet
6746960140 ipv6: RTAX_FEATURE_ALLFRAG causes inefficient TCP segment sizing
Quoting Tore Anderson from :
https://bugzilla.kernel.org/show_bug.cgi?id=42572

When RTAX_FEATURE_ALLFRAG is set on a route, the effective TCP segment
size does not take into account the size of the IPv6 Fragmentation
header that needs to be included in outbound packets, causing every
transmitted TCP segment to be fragmented across two IPv6 packets, the
latter of which will only contain 8 bytes of actual payload.

RTAX_FEATURE_ALLFRAG is typically set on a route in response to
receving a ICMPv6 Packet Too Big message indicating a Path MTU of less
than 1280 bytes. 1280 bytes is the minimum IPv6 MTU, however ICMPv6
PTBs with MTU < 1280 are still valid, in particular when an IPv6
packet is sent to an IPv4 destination through a stateless translator.
Any ICMPv4 Need To Fragment packets originated from the IPv4 part of
the path will be translated to ICMPv6 PTB which may then indicate an
MTU of less than 1280.

The Linux kernel refuses to reduce the effective MTU to anything below
1280 bytes, instead it sets it to exactly 1280 bytes, and
RTAX_FEATURE_ALLFRAG is also set. However, the TCP segment size appears
to be set to 1240 bytes (1280 Path MTU - 40 bytes of IPv6 header),
instead of 1232 (additionally taking into account the 8 bytes required
by the IPv6 Fragmentation extension header).

This in turn results in rather inefficient transmission, as every
transmitted TCP segment now is split in two fragments containing
1232+8 bytes of payload.

After this patch, all the outgoing packets that includes a
Fragmentation header all are "atomic" or "non-fragmented" fragments,
i.e., they both have Offset=0 and More Fragments=0.

With help from David S. Miller

Reported-by: Tore Anderson <tore@fud.no>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Tom Herbert <therbert@google.com>
Tested-by: Tore Anderson <tore@fud.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-27 00:03:34 -04:00
Neal Cardwell
900f65d361 tcp: move duplicate code from tcp_v4_init_sock()/tcp_v6_init_sock()
This commit moves the (substantial) common code shared between
tcp_v4_init_sock() and tcp_v6_init_sock() to a new address-family
independent function, tcp_init_sock().

Centralizing this functionality should help avoid drift issues,
e.g. where the IPv4 side is updated without a corresponding update to
IPv6. There was already some drift: IPv4 initialized snd_cwnd to
TCP_INIT_CWND, while the IPv6 side was still initializing snd_cwnd to
2 (in this case it should not matter, since snd_cwnd is also
initialized in tcp_init_metrics(), but the general risks and
maintenance overhead remain).

When diffing the old and new code, note that new tcp_init_sock()
function uses the order of steps from the tcp_v4_init_sock()
implementation (the order is slightly different in
tcp_v6_init_sock()).

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-21 16:36:42 -04:00
Pavel Emelyanov
ee9952831c tcp: Initial repair mode
This includes (according the the previous description):

* TCP_REPAIR sockoption

This one just puts the socket in/out of the repair mode.
Allowed for CAP_NET_ADMIN and for closed/establised sockets only.
When repair mode is turned off and the socket happens to be in
the established state the window probe is sent to the peer to
'unlock' the connection.

* TCP_REPAIR_QUEUE sockoption

This one sets the queue which we're about to repair. The
'no-queue' is set by default.

* TCP_QUEUE_SEQ socoption

Sets the write_seq/rcv_nxt of a selected repaired queue.
Allowed for TCP_CLOSE-d sockets only. When the socket changes
its state the other seq-s are changed by the kernel according
to the protocol rules (most of the existing code is actually
reused).

* Ability to forcibly bind a socket to a port

The sk->sk_reuse is set to SK_FORCE_REUSE.

* Immediate connect modification

The connect syscall initializes the connection, then directly jumps
to the code which finalizes it.

* Silent close modification

The close just aborts the connection (similar to SO_LINGER with 0
time) but without sending any FIN/RST-s to peer.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-21 15:52:25 -04:00
Pavel Emelyanov
370816aef0 tcp: Move code around
This is just the preparation patch, which makes the needed for
TCP repair code ready for use.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-21 15:52:25 -04:00
Neal Cardwell
f4f9f6e75d tcp: restore formatting of macros for tcp_skb_cb sacked field
Commit b82d1bb4 inadvertendly placed unrelated new code between
TCPCB_EVER_RETRANS and TCPCB_RETRANS and the other macros that refer
to the sacked field in the struct tcp_skb_cb (probably because there
was a misleading empty line there). This commit fixes up the
formatting so that all macros related to the sacked field are adjacent
again.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-16 14:38:16 -04:00
Eric Dumazet
95c9617472 net: cleanup unsigned to unsigned int
Use of "unsigned int" is preferred to bare "unsigned" in net tree.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15 12:44:40 -04:00
Eric Dumazet
fd4f2cead6 tcp: RFC6298 supersedes RFC2988bis
Updates some comments to track RFC6298

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: H.K. Jerry Chu <hkchu@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-14 15:24:26 -04:00
Linus Torvalds
ed2d265d12 The following text was taken from the original review request:
"[RFC - PATCH 0/7] consolidation of BUG support code."
 		https://lkml.org/lkml/2012/1/26/525
 --
 
 The changes shown here are to unify linux's BUG support under
 the one <linux/bug.h> file.  Due to historical reasons, we have
 some BUG code in bug.h and some in kernel.h -- i.e. the support for
 BUILD_BUG in linux/kernel.h predates the addition of linux/bug.h,
 but old code in kernel.h wasn't moved to bug.h at that time.  As
 a band-aid, kernel.h was including <asm/bug.h> to pseudo link them.
 
 This has caused confusion[1] and general yuck/WTF[2] reactions.
 Here is an example that violates the principle of least surprise:
 
       CC      lib/string.o
       lib/string.c: In function 'strlcat':
       lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON'
       make[2]: *** [lib/string.o] Error 1
       $
       $ grep linux/bug.h lib/string.c
       #include <linux/bug.h>
       $
 
 We've included <linux/bug.h> for the BUG infrastructure and yet we
 still get a compile fail!  [We've not kernel.h for BUILD_BUG_ON.]
 Ugh - very confusing for someone who is new to kernel development.
 
 With the above in mind, the goals of this changeset are:
 
 1) find and fix any include/*.h files that were relying on the
    implicit presence of BUG code.
 2) find and fix any C files that were consuming kernel.h and
    hence relying on implicitly getting some/all BUG code.
 3) Move the BUG related code living in kernel.h to <linux/bug.h>
 4) remove the asm/bug.h from kernel.h to finally break the chain.
 
 During development, the order was more like 3-4, build-test, 1-2.
 But to ensure that git history for bisect doesn't get needless
 build failures introduced, the commits have been reorderd to fix
 the problem areas in advance.
 
 [1]  https://lkml.org/lkml/2012/1/3/90
 [2]  https://lkml.org/lkml/2012/1/17/414
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Merge tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

Pull <linux/bug.h> cleanup from Paul Gortmaker:
 "The changes shown here are to unify linux's BUG support under the one
  <linux/bug.h> file.  Due to historical reasons, we have some BUG code
  in bug.h and some in kernel.h -- i.e.  the support for BUILD_BUG in
  linux/kernel.h predates the addition of linux/bug.h, but old code in
  kernel.h wasn't moved to bug.h at that time.  As a band-aid, kernel.h
  was including <asm/bug.h> to pseudo link them.

  This has caused confusion[1] and general yuck/WTF[2] reactions.  Here
  is an example that violates the principle of least surprise:

      CC      lib/string.o
      lib/string.c: In function 'strlcat':
      lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON'
      make[2]: *** [lib/string.o] Error 1
      $
      $ grep linux/bug.h lib/string.c
      #include <linux/bug.h>
      $

  We've included <linux/bug.h> for the BUG infrastructure and yet we
  still get a compile fail! [We've not kernel.h for BUILD_BUG_ON.] Ugh -
  very confusing for someone who is new to kernel development.

  With the above in mind, the goals of this changeset are:

  1) find and fix any include/*.h files that were relying on the
     implicit presence of BUG code.
  2) find and fix any C files that were consuming kernel.h and hence
     relying on implicitly getting some/all BUG code.
  3) Move the BUG related code living in kernel.h to <linux/bug.h>
  4) remove the asm/bug.h from kernel.h to finally break the chain.

  During development, the order was more like 3-4, build-test, 1-2.  But
  to ensure that git history for bisect doesn't get needless build
  failures introduced, the commits have been reorderd to fix the problem
  areas in advance.

	[1]  https://lkml.org/lkml/2012/1/3/90
	[2]  https://lkml.org/lkml/2012/1/17/414"

Fix up conflicts (new radeon file, reiserfs header cleanups) as per Paul
and linux-next.

* tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
  kernel.h: doesn't explicitly use bug.h, so don't include it.
  bug: consolidate BUILD_BUG_ON with other bug code
  BUG: headers with BUG/BUG_ON etc. need linux/bug.h
  bug.h: add include of it to various implicit C users
  lib: fix implicit users of kernel.h for TAINT_WARN
  spinlock: macroize assert_spin_locked to avoid bug.h dependency
  x86: relocate get/set debugreg fcns to include/asm/debugreg.
2012-03-24 10:08:39 -07:00
Paul Gortmaker
187f1882b5 BUG: headers with BUG/BUG_ON etc. need linux/bug.h
If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any
other BUG variant in a static inline (i.e. not in a #define) then
that header really should be including <linux/bug.h> and not just
expecting it to be implicitly present.

We can make this change risk-free, since if the files using these
headers didn't have exposure to linux/bug.h already, they would have
been causing compile failures/warnings.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-03-04 17:54:34 -05:00
David S. Miller
b4017c5368 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/broadcom/tg3.c

Conflicts in the statistics regression bug fix from 'net',
but happily Matt Carlson originally posted the fix against
'net-next' so I used that to resolve this.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-01 17:57:40 -05:00
Neal Cardwell
ecb9719236 tcp: fix comment for tp->highest_sack
There was an off-by-one error in the comments describing the
highest_sack field in struct tcp_sock. The comments previously claimed
that it was the "start sequence of the highest skb with SACKed
bit". This commit fixes the comments to note that it is the "start
sequence of the skb just *after* the highest skb with SACKed bit".

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-28 15:06:33 -05:00
David S. Miller
dd48dc34fe Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-02-04 16:39:32 -05:00
Arun Sharma
efcdbf24fd net: Disambiguate kernel message
Some of our machines were reporting:

TCP: too many of orphaned sockets

even when the number of orphaned sockets was well below the
limit.

We print a different message depending on whether we're out
of TCP memory or there are too many orphaned sockets.

Also move the check out of line and cleanup the messages
that were printed.

Signed-off-by: Arun Sharma <asharma@fb.com>
Suggested-by: Mohan Srinivasan <mohan@fb.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: David Miller <davem@davemloft.net>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-01 14:41:50 -05:00
Eric Dumazet
a8afca0329 tcp: md5: protects md5sig_info with RCU
This patch makes sure we use appropriate memory barriers before
publishing tp->md5sig_info, allowing tcp_md5_do_lookup() being used from
tcp_v4_send_reset() without holding socket lock (upcoming patch from
Shawn Lu)

Note we also need to respect rcu grace period before its freeing, since
we can free socket without this grace period thanks to
SLAB_DESTROY_BY_RCU

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Shawn Lu <shawn.lu@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-01 02:11:47 -05:00
Eric Dumazet
a915da9b69 tcp: md5: rcu conversion
In order to be able to support proper RST messages for TCP MD5 flows, we
need to allow access to MD5 keys without locking listener socket.

This conversion is a nice cleanup, and shrinks size of timewait sockets
by 80 bytes.

IPv6 code reuses generic code found in IPv4 instead of duplicating it.

Control path uses GFP_KERNEL allocations instead of GFP_ATOMIC.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Shawn Lu <shawn.lu@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-31 12:14:00 -05:00
Eric Dumazet
a2d91241a8 tcp: md5: remove obsolete md5_add() method
We no longer use md5_add() method from struct tcp_sock_af_ops

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-31 12:13:59 -05:00
Glauber Costa
4acb41903b net/tcp: Fix tcp memory limits initialization when !CONFIG_SYSCTL
sysctl_tcp_mem() initialization was moved to sysctl_tcp_ipv4.c
in commit 3dc43e3e4d, since it
became a per-ns value.

That code, however, will never run when CONFIG_SYSCTL is
disabled, leading to bogus values on those fields - causing hung
TCP sockets.

This patch fixes it by keeping an initialization code in
tcp_init(). It will be overwritten by the first net namespace
init if CONFIG_SYSCTL is compiled in, and do the right thing if
it is compiled out.

It is also named properly as tcp_init_mem(), to properly signal
its non-sysctl side effect on TCP limits.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Glauber Costa <glommer@parallels.com>
Cc: David S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/4F22D05A.8030604@parallels.com
[ renamed the function, tidied up the changelog a bit ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-30 12:41:06 -05:00
Vijay Subramanian
ab56222a32 tcp: Replace constants with #define macros
to record the state of SACK/FACK and DSACK for better readability and maintenance.

Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-21 01:03:23 -05:00
Glauber Costa
3dc43e3e4d per-netns ipv4 sysctl_tcp_mem
This patch allows each namespace to independently set up
its levels for tcp memory pressure thresholds. This patch
alone does not buy much: we need to make this values
per group of process somehow. This is achieved in the
patches that follows in this patchset.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: David S. Miller <davem@davemloft.net>
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-12 19:04:11 -05:00
Glauber Costa
180d8cd942 foundations of per-cgroup memory pressure controlling.
This patch replaces all uses of struct sock fields' memory_pressure,
memory_allocated, sockets_allocated, and sysctl_mem to acessor
macros. Those macros can either receive a socket argument, or a mem_cgroup
argument, depending on the context they live in.

Since we're only doing a macro wrapping here, no performance impact at all is
expected in the case where we don't have cgroups disabled.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Reviewed-by: Hiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com>
CC: David S. Miller <davem@davemloft.net>
CC: Eric W. Biederman <ebiederm@xmission.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-12 19:04:10 -05:00
Eric Dumazet
dfd56b8b38 net: use IS_ENABLED(CONFIG_IPV6)
Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-11 18:25:16 -05:00
Neal Cardwell
6b5a5c0dbb tcp: do not scale TSO segment size with reordering degree
Since 2005 (c1b4a7e695)
tcp_tso_should_defer has been using tcp_max_burst() as a target limit
for deciding how large to make outgoing TSO packets when not using
sysctl_tcp_tso_win_divisor. But since 2008
(dd9e0dda66) tcp_max_burst() returns the
reordering degree. We should not have tcp_tso_should_defer attempt to
build larger segments just because there is more reordering. This
commit splits the notion of deferral size used in TSO from the notion
of burst size used in cwnd moderation, and returns the TSO deferral
limit to its original value.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-29 00:29:41 -05:00
Michał Mirosław
c8f44affb7 net: introduce and use netdev_features_t for device features sets
v2:	add couple missing conversions in drivers
	split unexporting netdev_fix_features()
	implemented %pNF
	convert sock::sk_route_(no?)caps

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-16 17:43:10 -05:00
Arjan van de Ven
73cb88ecb9 net: make the tcp and udp file_operations for the /proc stuff const
the tcp and udp code creates a set of struct file_operations at runtime
while it can also be done at compile time, with the added benefit of then
having these file operations be const.

the trickiest part was to get the "THIS_MODULE" reference right; the naive
method of declaring a struct in the place of registration would not work
for this reason.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-01 17:56:14 -04:00
Flavio Leitner
78d81d15b7 TCP: remove TCP_DEBUG
It was enabled by default and the messages guarded
by the define are useful.

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-24 17:36:08 -04:00
Eric Dumazet
318cf7aaa0 tcp: md5: add more const attributes
Now tcp_md5_hash_header() has a const tcphdr argument, we can add more
const attributes to callers.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-24 02:46:04 -04:00
Eric Dumazet
ca35a0ef85 tcp: md5: dont write skb head in tcp_md5_hash_header()
tcp_md5_hash_header() writes into skb header a temporary zero value,
this might confuse other users of this area.

Since tcphdr is small (20 bytes), copy it in a temporary variable and
make the change in the copy.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-24 01:52:35 -04:00
Eric Dumazet
cf533ea53e tcp: add const qualifiers where possible
Adding const qualifiers to pointers can ease code review, and spot some
bugs. It might allow compiler to optimize code further.

For example, is it legal to temporary write a null cksum into tcphdr
in tcp_md5_hash_header() ? I am afraid a sniffer could catch the
temporary null value...

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-21 05:22:42 -04:00
Eric Dumazet
4de075e043 tcp: rename tcp_skb_cb flags
Rename struct tcp_skb_cb "flags" to "tcp_flags" to ease code review and
maintenance.

Its content is a combination of FIN/SYN/RST/PSH/ACK/URG/ECE/CWR flags

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-27 13:25:05 -04:00
Eric Dumazet
b82d1bb4fd tcp: unalias tcp_skb_cb flags and ip_dsfield
struct tcp_skb_cb contains a "flags" field containing either tcp flags
or IP dsfield depending on context (input or output path)

Introduce ip_dsfield to make the difference clear and ease maintenance.
If later we want to save space, we can union flags/ip_dsfield

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-27 02:20:08 -04:00
Eric Dumazet
7a269ffad7 tcp: ECN blackhole should not force quickack mode
While playing with a new ADSL box at home, I discovered that ECN
blackhole can trigger suboptimal quickack mode on linux : We send one
ACK for each incoming data frame, without any delay and eventual
piggyback.

This is because TCP_ECN_check_ce() considers that if no ECT is seen on a
segment, this is because this segment was a retransmit.

Refine this heuristic and apply it only if we seen ECT in a previous
segment, to detect ECN blackhole at IP level.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Jamal Hadi Salim <jhs@mojatatu.com>
CC: Jerry Chu <hkchu@google.com>
CC: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
CC: Jim Gettys <jg@freedesktop.org>
CC: Dave Taht <dave.taht@gmail.com>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-27 00:58:44 -04:00
David S. Miller
8decf86879 Merge branch 'master' of github.com:davem330/net
Conflicts:
	MAINTAINERS
	drivers/net/Kconfig
	drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c
	drivers/net/ethernet/broadcom/tg3.c
	drivers/net/wireless/iwlwifi/iwl-pci.c
	drivers/net/wireless/iwlwifi/iwl-trans-tx-pcie.c
	drivers/net/wireless/rt2x00/rt2800usb.c
	drivers/net/wireless/wl12xx/main.c
2011-09-22 03:23:13 -04:00
Eric Dumazet
e05c82d366 tcp: fix build error if !CONFIG_SYN_COOKIES
commit 946cedccbd (tcp: Change possible SYN flooding messages)
added a build error if CONFIG_SYN_COOKIES=n

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-18 21:48:01 -04:00
Eric Dumazet
765cf9976e tcp: md5: remove one indirection level in tcp_md5sig_pool
tcp_md5sig_pool is currently an 'array' (a percpu object) of pointers to
struct tcp_md5sig_pool. Only the pointers are NUMA aware, but objects
themselves are all allocated on a single node.

Remove this extra indirection to get proper percpu memory (NUMA aware)
and make code simpler.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-17 01:15:46 -04:00
Eric Dumazet
946cedccbd tcp: Change possible SYN flooding messages
"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 <eric.dumazet@gmail.com>
CC: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-15 14:49:43 -04:00
Jerry Chu
9ad7c049f0 tcp: RFC2988bis + taking RTT sample from 3WHS for the passive open side
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 <hkchu@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-08 17:05:30 -07:00
Shan Wei
089c34827e tcp: Remove debug macro of TCP_CHECK_TIMER
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 <shanwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-20 11:10:14 -08:00
David S. Miller
7eb38527c4 tcp: Add reference to initial CWND ietf draft.
Suggested by Alexander Zimmermann

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-05 18:13:45 -08:00
David S. Miller
442b9635c5 tcp: Increase the initial congestion window to 10.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Nandita Dukkipati <nanditad@google.com>
2011-02-02 20:48:47 -08:00
Michał Mirosław
04ed3e741d net: change netdev->features to u32
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 <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-24 15:32:47 -08:00
Nandita Dukkipati
356f039822 TCP: increase default initial receive window.
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 <nanditad@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-20 21:33:00 -08:00
Shan Wei
4c306a9291 net: kill unused macros
These macros never be used, so remove them.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-19 21:59:35 -08:00
Eric Dumazet
bc2ce894e1 tcp: relax tcp_paws_check()
Some windows versions have wrong RFC1323 implementations, with SYN and
SYNACKS messages containing zero tcp timestamps.

We relaxed in commit fc1ad92dfc 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 <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-16 14:08:34 -08:00
Shan Wei
dca9b2404a net: kill unused macros from head file
These macros have been defined for several years since v2.6.12-rc2(tracing by git),
but never be used. So remove them.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-02 13:27:33 -08:00
David S. Miller
ccb7c410dd timewait_sock: Create and use getpeer op.
The only thing AF-specific about remembering the timestamp
for a time-wait TCP socket is getting the peer.

Abstract that behind a new timewait_sock_ops vector.

Support for real IPV6 sockets is not filled in yet, but
curiously this makes timewait recycling start to work
for v4-mapped ipv6 sockets.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-01 18:09:13 -08:00
David S. Miller
3f419d2d48 inet: Turn ->remember_stamp into ->get_peer in connection AF ops.
Then we can make a completely generic tcp_remember_stamp()
that uses ->get_peer() as a helper, minimizing the AF specific
code and minimizing the eventual code duplication when we implement
the ipv6 side of TW recycling.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-30 12:28:06 -08:00
Eric Dumazet
8d987e5c75 net: avoid limits overflow
Robin Holt tried to boot a 16TB machine and found some limits were
reached : sysctl_tcp_mem[2], sysctl_udp_mem[2]

We can switch infrastructure to use long "instead" of "int", now
atomic_long_t primitives are available for free.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reported-by: Robin Holt <holt@sgi.com>
Reviewed-by: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-10 12:12:00 -08:00
stephen hemminger
1b9f409293 tcp: tcp_enter_quickack_mode can be static
Function only used in tcp_input.c

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-29 19:45:36 -07:00
David S. Miller
e40051d134 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/qlcnic/qlcnic_init.c
	net/ipv4/ip_output.c
2010-09-27 01:03:03 -07:00
Alexey Kuznetsov
01f83d6984 tcp: Prevent overzealous packetization by SWS logic.
If peer uses tiny MSS (say, 75 bytes) and similarly tiny advertised
window, the SWS logic will packetize to half the MSS unnecessarily.

This causes problems with some embedded devices.

However for large MSS devices we do want to half-MSS packetize
otherwise we never get enough packets into the pipe for things
like fast retransmit and recovery to work.

Be careful also to handle the case where MSS > window, otherwise
we'll never send until the probe timer.

Reported-by: ツ Leandro Melo de Sales <leandroal@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-15 12:01:44 -07:00
David S. Miller
e548833df8 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/mac80211/main.c
2010-09-09 22:27:33 -07:00
Gerrit Renker
3d5b99ae82 TCP: update initial windows according to RFC 5681
This updates the use of larger initial windows, as originally specified in
RFC 3390, to use the newer IW values specified in RFC 5681, section 3.1.

The changes made in RFC 5681 are:
 a) the setting now is more clearly specified in units of segments (as the
    comments  by John Heffner emphasized, this was not very clear in RFC 3390);
 b) for connections with 1095 < SMSS <= 2190 there is now a change:
    - RFC 3390 says that IW <= 4380,
    - RFC 5681 says that IW = 3 * SMSS <= 6570.

Since RFC 3390 is older and "only" proposed standard, whereas the newer RFC 5681
is already draft standard, it seems preferable to use the newer IW variant.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-30 13:50:44 -07:00
Gerrit Renker
22b71c8f4f tcp/dccp: Consolidate common code for RFC 3390 conversion
This patch consolidates initial-window code common to TCP and CCID-2:
 * TCP uses RFC 3390 in a packet-oriented manner (tcp_input.c) and
 * CCID-2 uses RFC 3390 in packet-oriented manner (RFC 4341).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-30 13:45:26 -07:00
David S. Miller
ad1af0fedb tcp: Combat per-cpu skew in orphan tests.
As reported by Anton Blanchard when we use
percpu_counter_read_positive() to make our orphan socket limit checks,
the check can be off by up to num_cpus_online() * batch (which is 32
by default) which on a 128 cpu machine can be as large as the default
orphan limit itself.

Fix this by doing the full expensive sum check if the optimized check
triggers.

Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
2010-08-25 02:27:49 -07:00
Eric Dumazet
f86586fa48 tcp: sizeof struct tcp_skb_cb is 44
Correct comment stating sizeof(struct tcp_skb_cb) is 36 or 40, since its
44 bytes, since commit 951dbc8ac7 ([IPV6]: Move nextheader offset
to the IP6CB).

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-15 21:41:00 -07:00
Changli Gao
7ba4291007 inet, inet6: make tcp_sendmsg() and tcp_sendpage() through inet_sendmsg() and inet_sendpage()
a new boolean flag no_autobind is added to structure proto to avoid the autobind
calls when the protocol is TCP. Then sock_rps_record_flow() is called int the
TCP's sendmsg() and sendpage() pathes.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
----
 include/net/inet_common.h |    4 ++++
 include/net/sock.h        |    1 +
 include/net/tcp.h         |    8 ++++----
 net/ipv4/af_inet.c        |   15 +++++++++------
 net/ipv4/tcp.c            |   11 +++++------
 net/ipv4/tcp_ipv4.c       |    3 +++
 net/ipv6/af_inet6.c       |    8 ++++----
 net/ipv6/tcp_ipv6.c       |    3 +++
 8 files changed, 33 insertions(+), 20 deletions(-)
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-12 20:21:46 -07:00
Changli Gao
53d3176b28 net: cleanups
remove useless blanks.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
----
 include/net/inet_common.h |   55 ++++-------
 include/net/tcp.h         |  222 +++++++++++++++++-----------------------------
 include/net/udp.h         |   38 +++----
 3 files changed, 123 insertions(+), 192 deletions(-)
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-12 20:21:45 -07:00
Florian Westphal
172d69e63c syncookies: add support for ECN
Allows use of ECN when syncookies are in effect by encoding ecn_ok
into the syn-ack tcp timestamp.

While at it, remove a uneeded #ifdef CONFIG_SYN_COOKIES.
With CONFIG_SYN_COOKIES=nm want_cookie is ifdef'd to 0 and gcc
removes the "if (0)".

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-26 22:00:03 -07:00
Florian Westphal
8c76368174 syncookies: check decoded options against sysctl settings
Discard the ACK if we find options that do not match current sysctl
settings.

Previously it was possible to create a connection with sack, wscale,
etc. enabled even if the feature was disabled via sysctl.

Also remove an unneeded call to tcp_sack_reset() in
cookie_check_timestamp: Both call sites (cookie_v4_check,
cookie_v6_check) zero "struct tcp_options_received", hand it to
tcp_parse_options() (which does not change tcp_opt->num_sacks/dsack)
and then call cookie_check_timestamp().

Even if num_sacks/dsacks were changed, the structure is allocated on
the stack and after cookie_check_timestamp returns only a few selected
members are copied to the inet_request_sock.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-16 14:42:15 -07:00
Changli Gao
a3433f35a5 tcp: unify tcp flag macros
unify tcp flag macros: TCPHDR_FIN, TCPHDR_SYN, TCPHDR_RST, TCPHDR_PSH,
TCPHDR_ACK, TCPHDR_URG, TCPHDR_ECE and TCPHDR_CWR. TCBCB_FLAG_* are replaced
with the corresponding TCPHDR_*.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
----
 include/net/tcp.h                      |   24 ++++++-------
 net/ipv4/tcp.c                         |    8 ++--
 net/ipv4/tcp_input.c                   |    2 -
 net/ipv4/tcp_output.c                  |   59 ++++++++++++++++-----------------
 net/netfilter/nf_conntrack_proto_tcp.c |   32 ++++++-----------
 net/netfilter/xt_TCPMSS.c              |    4 --
 6 files changed, 58 insertions(+), 71 deletions(-)
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-15 11:56:19 -07:00
Tom Herbert
a8b690f98b tcp: Fix slowness in read /proc/net/tcp
This patch address a serious performance issue in reading the
TCP sockets table (/proc/net/tcp).

Reading the full table is done by a number of sequential read
operations.  At each read operation, a seek is done to find the
last socket that was previously read.  This seek operation requires
that the sockets in the table need to be counted up to the current
file position, and to count each of these requires taking a lock for
each non-empty bucket.  The whole algorithm is O(n^2).

The fix is to cache the last bucket value, offset within the bucket,
and the file position returned by the last read operation.   On the
next sequential read, the bucket and offset are used to find the
last read socket immediately without needing ot scan the previous
buckets  the table.  This algorithm t read the whole table is O(n).

The improvement offered by this patch is easily show by performing
cat'ing /proc/net/tcp on a machine with a lot of connections.  With
about 182K connections in the table, I see the following:

- Without patch
time cat /proc/net/tcp > /dev/null

real	1m56.729s
user	0m0.214s
sys	1m56.344s

- With patch
time cat /proc/net/tcp > /dev/null

real	0m0.894s
user	0m0.290s
sys	0m0.594s

Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-07 00:43:42 -07:00
David S. Miller
6811d58fc1 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	include/linux/if_link.h
2010-05-16 22:26:58 -07:00
Eric Dumazet
35790c0421 tcp: fix MD5 (RFC2385) support
TCP MD5 support uses percpu data for temporary storage. It currently
disables preemption so that same storage cannot be reclaimed by another
thread on same cpu.

We also have to make sure a softirq handler wont try to use also same
context. Various bug reports demonstrated corruptions.

Fix is to disable preemption and BH.

Reported-by: Bhaskar Dutta <bhaskie@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-16 00:34:04 -07:00
Flavio Leitner
6c37e5de45 TCP: avoid to send keepalive probes if receiving data
RFC 1122 says the following:
...
  Keep-alive packets MUST only be sent when no data or
  acknowledgement packets have been received for the
  connection within an interval.
...

The acknowledgement packet is reseting the keepalive
timer but the data packet isn't. This patch fixes it by
checking the timestamp of the last received data packet
too when the keepalive timer expires.

Signed-off-by: Flavio Leitner <fleitner@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-27 12:53:25 -07:00
Tom Herbert
aa2ea0586d tcp: fix outsegs stat for TSO segments
Account for TSO segments of an skb in TCP_MIB_OUTSEGS counter.  Without
doing this, the counter can be off by orders of magnitude from the
actual number of segments sent.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-22 16:00:00 -07:00
Eric Dumazet
aa39514516 net: sk_sleep() helper
Define a new function to return the waitqueue of a "struct sock".

static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
	return sk->sk_sleep;
}

Change all read occurrences of sk_sleep by a call to this function.

Needed for a future RCU conversion. sk_sleep wont be a field directly
available.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-20 16:37:13 -07:00
Herbert Xu
bb29624614 inet: Remove unused send_check length argument
inet: Remove unused send_check length argument

This patch removes the unused length argument from the send_check
function in struct inet_connection_sock_af_ops.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Yinghai <yinghai.lu@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-11 15:29:09 -07:00
Mike Galbraith
c839d30a41 net: add scheduler sync hint to tcp_prequeue().
Decreases the odds wakee will suffer from frequent cache misses.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-04 00:53:51 -08:00
Andreas Petlund
7e38017557 net: TCP thin dupack
This patch enables fast retransmissions after one dupACK for
TCP if the stream is identified as thin. This will reduce
latencies for thin streams that are not able to trigger fast
retransmissions due to high packet interarrival time. This
mechanism is only active if enabled by iocontrol or syscontrol
and the stream is identified as thin.

Signed-off-by: Andreas Petlund <apetlund@simula.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-18 15:43:09 -08:00
Andreas Petlund
36e31b0af5 net: TCP thin linear timeouts
This patch will make TCP use only linear timeouts if the
stream is thin. This will help to avoid the very high latencies
that thin stream suffer because of exponential backoff. This
mechanism is only active if enabled by iocontrol or syscontrol
and the stream is identified as thin. A maximum of 6 linear
timeouts is tried before exponential backoff is resumed.

Signed-off-by: Andreas Petlund <apetlund@simula.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-18 15:43:08 -08:00
Andreas Petlund
5aa4b32fc8 net: TCP thin-stream detection
Inline function to dynamically detect thin streams based on
the number of packets in flight. Used to dynamically trigger
thin-stream mechanisms if enabled by ioctl or sysctl.

Signed-off-by: Andreas Petlund <apetlund@simula.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-18 15:43:07 -08:00
Tejun Heo
7d720c3e4f percpu: add __percpu sparse annotations to net
Add __percpu sparse annotations to net.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors.  This patch doesn't affect normal builds.

The macro and type tricks around snmp stats make things a bit
interesting.  DEFINE/DECLARE_SNMP_STAT() macros mark the target field
as __percpu and SNMP_UPD_PO_STATS() macro is updated accordingly.  All
snmp_mib_*() users which used to cast the argument to (void **) are
updated to cast it to (void __percpu **).

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Vlad Yasevich <vladislav.yasevich@hp.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 23:05:38 -08:00
Octavian Purdila
72659ecce6 tcp: account SYN-ACK timeouts & retransmissions
Currently we don't increment SYN-ACK timeouts & retransmissions
although we do increment the same stats for SYN. We seem to have lost
the SYN-ACK accounting with the introduction of tcp_syn_recv_timer
(commit 2248761e in the netdev-vger-cvs tree).

This patch fixes this issue. In the process we also rename the v4/v6
syn/ack retransmit functions for clarity. We also add a new
request_socket operations (syn_ack_timeout) so we can keep code in
inet_connection_sock.c protocol agnostic.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-01-17 19:09:39 -08:00
laurent chavey
31d12926e3 net: Add rtnetlink init_rcvwnd to set the TCP initial receive window
Add rtnetlink init_rcvwnd to set the TCP initial receive window size
advertised by passive and active TCP connections.
The current Linux TCP implementation limits the advertised TCP initial
receive window to the one prescribed by slow start. For short lived
TCP connections used for transaction type of traffic (i.e. http
requests), bounding the advertised TCP initial receive window results
in increased latency to complete the transaction.
Support for setting initial congestion window is already supported
using rtnetlink init_cwnd, but the feature is useless without the
ability to set a larger TCP initial receive window.
The rtnetlink init_rcvwnd allows increasing the TCP initial receive
window, allowing TCP connection to advertise larger TCP receive window
than the ones bounded by slow start.

Signed-off-by: Laurent Chavey <chavey@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-23 14:13:30 -08:00
Krishna Kumar
12d50c46dc tcp: Remove check in __tcp_push_pending_frames
tcp_push checks tcp_send_head and calls __tcp_push_pending_frames,
which again checks tcp_send_head, and this unnecessary check is
done for every other caller of __tcp_push_pending_frames.

Remove tcp_send_head check in __tcp_push_pending_frames and add
the check to tcp_push_pending_frames. Other functions call
__tcp_push_pending_frames only when tcp_send_head would evaluate
to true.

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-23 14:13:28 -08:00
David S. Miller
bb5b7c1126 tcp: Revert per-route SACK/DSACK/TIMESTAMP changes.
It creates a regression, triggering badness for SYN_RECV
sockets, for example:

[19148.022102] Badness at net/ipv4/inet_connection_sock.c:293
[19148.022570] NIP: c02a0914 LR: c02a0904 CTR: 00000000
[19148.023035] REGS: eeecbd30 TRAP: 0700   Not tainted  (2.6.32)
[19148.023496] MSR: 00029032 <EE,ME,CE,IR,DR>  CR: 24002442  XER: 00000000
[19148.024012] TASK = eee9a820[1756] 'privoxy' THREAD: eeeca000

This is likely caused by the change in the 'estab' parameter
passed to tcp_parse_options() when invoked by the functions
in net/ipv4/tcp_minisocks.c

But even if that is fixed, the ->conn_request() changes made in
this patch series is fundamentally wrong.  They try to use the
listening socket's 'dst' to probe the route settings.  The
listening socket doesn't even have a route, and you can't
get the right route (the child request one) until much later
after we setup all of the state, and it must be done by hand.

This stuff really isn't ready, so the best thing to do is a
full revert.  This reverts the following commits:

f55017a93f
022c3f7d82
1aba721eba
cda42ebd67
345cda2fd6
dc343475ed
05eaade278
6a2a2d6bf8

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-15 20:56:42 -08:00
David S. Miller
501706565b Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
	include/net/tcp.h
2009-12-11 17:12:17 -08:00
Linus Torvalds
4ef58d4e2a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits)
  tree-wide: fix misspelling of "definition" in comments
  reiserfs: fix misspelling of "journaled"
  doc: Fix a typo in slub.txt.
  inotify: remove superfluous return code check
  hdlc: spelling fix in find_pvc() comment
  doc: fix regulator docs cut-and-pasteism
  mtd: Fix comment in Kconfig
  doc: Fix IRQ chip docs
  tree-wide: fix assorted typos all over the place
  drivers/ata/libata-sff.c: comment spelling fixes
  fix typos/grammos in Documentation/edac.txt
  sysctl: add missing comments
  fs/debugfs/inode.c: fix comment typos
  sgivwfb: Make use of ARRAY_SIZE.
  sky2: fix sky2_link_down copy/paste comment error
  tree-wide: fix typos "couter" -> "counter"
  tree-wide: fix typos "offest" -> "offset"
  fix kerneldoc for set_irq_msi()
  spidev: fix double "of of" in comment
  comment typo fix: sybsystem -> subsystem
  ...
2009-12-09 19:43:33 -08:00
Damian Lukowski
2f7de5710a tcp: Stalling connections: Move timeout calculation routine
This patch moves retransmits_timed_out() from include/net/tcp.h
to tcp_timer.c, where it is used.

Reported-by: Frederic Leroy <fredo@starox.org>
Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-08 20:56:11 -08:00
Damian Lukowski
07f29bc5bb tcp: Stalling connections: Fix timeout calculation routine
This patch fixes a problem in the TCP connection timeout calculation.
Currently, timeout decisions are made on the basis of the current
tcp_time_stamp and retrans_stamp, which is usually set at the first
retransmission.
However, if the retransmission fails in tcp_retransmit_skb(),
retrans_stamp is not updated and remains zero. This leads to wrong
decisions in retransmits_timed_out() if tcp_time_stamp is larger than
the specified timeout, which is very likely.
In this case, the TCP connection dies after the first attempted
(and unsuccessful) retransmission.

With this patch, tcp_skb_cb->when is used instead, when retrans_stamp
is not available.

This bug has been introduced together with retransmits_timed_out() in
2.6.32, as the number of retransmissions has been used for timeout
decisions before. The corresponding commit was
6fa12c8503 (Revert Backoff [v3]:
Calculate TCP's connection close threshold as a time value.).

Thanks to Ilpo Järvinen for code suggestions and Frederic Leroy for
testing.

Reported-by: Frederic Leroy <fredo@starox.org>
Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-08 20:56:11 -08:00
André Goddard Rosa
af901ca181 tree-wide: fix assorted typos all over the place
That is "success", "unknown", "through", "performance", "[re|un]mapping"
, "access", "default", "reasonable", "[con]currently", "temperature"
, "channel", "[un]used", "application", "example","hierarchy", "therefore"
, "[over|under]flow", "contiguous", "threshold", "enough" and others.

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-04 15:39:55 +01:00
Ilpo Järvinen
8818a9d884 tcp: clear hints to avoid a stale one (nfs only affected?)
Eric Dumazet mentioned in a context of another problem:

"Well, it seems NFS reuses its socket, so maybe we miss some
cleaning as spotted in this old patch"

I've not check under which conditions that actually happens but
if true, we need to make sure we don't accidently leave stale
hints behind when the write queue had to be purged (whether reusing
with NFS can actually happen if purging took place is something I'm
not sure of).

...At least it compiles.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02 22:24:02 -08:00
William Allen Simpson
4957faade1 TCPCT part 1g: Responder Cookie => Initiator
Parse incoming TCP_COOKIE option(s).

Calculate <SYN,ACK> TCP_COOKIE option.

Send optional <SYN,ACK> data.

This is a significantly revised implementation of an earlier (year-old)
patch that no longer applies cleanly, with permission of the original
author (Adam Langley):

    http://thread.gmane.org/gmane.linux.network/102586

Requires:
   TCPCT part 1a: add request_values parameter for sending SYNACK
   TCPCT part 1b: generate Responder Cookie secret
   TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS
   TCPCT part 1d: define TCP cookie option, extend existing struct's
   TCPCT part 1e: implement socket option TCP_COOKIE_TRANSACTIONS
   TCPCT part 1f: Initiator Cookie => Responder

Signed-off-by: William.Allen.Simpson@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02 22:07:26 -08:00
William Allen Simpson
435cf559f0 TCPCT part 1d: define TCP cookie option, extend existing struct's
Data structures are carefully composed to require minimal additions.
For example, the struct tcp_options_received cookie_plus variable fits
between existing 16-bit and 8-bit variables, requiring no additional
space (taking alignment into consideration).  There are no additions to
tcp_request_sock, and only 1 pointer in tcp_sock.

This is a significantly revised implementation of an earlier (year-old)
patch that no longer applies cleanly, with permission of the original
author (Adam Langley):

    http://thread.gmane.org/gmane.linux.network/102586

The principle difference is using a TCP option to carry the cookie nonce,
instead of a user configured offset in the data.  This is more flexible and
less subject to user configuration error.  Such a cookie option has been
suggested for many years, and is also useful without SYN data, allowing
several related concepts to use the same extension option.

    "Re: SYN floods (was: does history repeat itself?)", September 9, 1996.
    http://www.merit.net/mail.archives/nanog/1996-09/msg00235.html

    "Re: what a new TCP header might look like", May 12, 1998.
    ftp://ftp.isi.edu/end2end/end2end-interest-1998.mail

These functions will also be used in subsequent patches that implement
additional features.

Requires:
   TCPCT part 1a: add request_values parameter for sending SYNACK
   TCPCT part 1b: generate Responder Cookie secret
   TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS

Signed-off-by: William.Allen.Simpson@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02 22:07:25 -08:00
William Allen Simpson
519855c508 TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS
Define sysctl (tcp_cookie_size) to turn on and off the cookie option
default globally, instead of a compiled configuration option.

Define per socket option (TCP_COOKIE_TRANSACTIONS) for setting constant
data values, retrieving variable cookie values, and other facilities.

Move inline tcp_clear_options() unchanged from net/tcp.h to linux/tcp.h,
near its corresponding struct tcp_options_received (prior to changes).

This is a straightforward re-implementation of an earlier (year-old)
patch that no longer applies cleanly, with permission of the original
author (Adam Langley):

    http://thread.gmane.org/gmane.linux.network/102586

These functions will also be used in subsequent patches that implement
additional features.

Requires:
   net: TCP_MSS_DEFAULT, TCP_MSS_DESIRED

Signed-off-by: William.Allen.Simpson@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02 22:07:24 -08:00
William Allen Simpson
da5c78c826 TCPCT part 1b: generate Responder Cookie secret
Define (missing) hash message size for SHA1.

Define hashing size constants specific to TCP cookies.

Add new function: tcp_cookie_generator().

Maintain global secret values for tcp_cookie_generator().

This is a significantly revised implementation of earlier (15-year-old)
Photuris [RFC-2522] code for the KA9Q cooperative multitasking platform.

Linux RCU technique appears to be well-suited to this application, though
neither of the circular queue items are freed.

These functions will also be used in subsequent patches that implement
additional features.

Signed-off-by: William.Allen.Simpson@gmail.com
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02 22:07:23 -08:00
William Allen Simpson
e6b4d11367 TCPCT part 1a: add request_values parameter for sending SYNACK
Add optional function parameters associated with sending SYNACK.
These parameters are not needed after sending SYNACK, and are not
used for retransmission.  Avoids extending struct tcp_request_sock,
and avoids allocating kernel memory.

Also affects DCCP as it uses common struct request_sock_ops,
but this parameter is currently reserved for future use.

Signed-off-by: William.Allen.Simpson@gmail.com
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02 22:07:23 -08:00
William Allen Simpson
bee7ca9ec0 net: TCP_MSS_DEFAULT, TCP_MSS_DESIRED
Define two symbols needed in both kernel and user space.

Remove old (somewhat incorrect) kernel variant that wasn't used in
most cases.  Default should apply to both RMSS and SMSS (RFC2581).

Replace numeric constants with defined symbols.

Stand-alone patch, originally developed for TCPCT.

Signed-off-by: William.Allen.Simpson@gmail.com
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-13 20:38:48 -08:00
Eric Dumazet
fd2c3ef761 net: cleanup include/net
This cleanup patch puts struct/union/enum opening braces,
in first line to ease grep games.

struct something
{

becomes :

struct something {

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-04 05:06:25 -08:00
Gilad Ben-Yossef
022c3f7d82 Allow tcp_parse_options to consult dst entry
We need tcp_parse_options to be aware of dst_entry to
take into account per dst_entry TCP options settings

Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-29 01:28:41 -07:00
David S. Miller
b7058842c9 net: Make setsockopt() optlen be unsigned.
This provides safety against negative optlen at the type
level instead of depending upon (sometimes non-trivial)
checks against this sprinkled all over the the place, in
each and every implementation.

Based upon work done by Arjan van de Ven and feedback
from Linus Torvalds.

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-30 16:12:20 -07:00
Ilpo Järvinen
0b6a05c1db tcp: fix ssthresh u16 leftover
It was once upon time so that snd_sthresh was a 16-bit quantity.
...That has not been true for long period of time. I run across
some ancient compares which still seem to trust such legacy.
Put all that magic into a single place, I hopefully found all
of them.

Compile tested, though linking of allyesconfig is ridiculous
nowadays it seems.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-15 01:30:10 -07:00
Wu Fengguang
aa1330766c tcp: replace hard coded GFP_KERNEL with sk_allocation
This fixed a lockdep warning which appeared when doing stress
memory tests over NFS:

	inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.

	page reclaim => nfs_writepage => tcp_sendmsg => lock sk_lock

	mount_root => nfs_root_data => tcp_close => lock sk_lock =>
			tcp_send_fin => alloc_skb_fclone => page reclaim

David raised a concern that if the allocation fails in tcp_send_fin(), and it's
GFP_ATOMIC, we are going to yield() (which sleeps) and loop endlessly waiting
for the allocation to succeed.

But fact is, the original GFP_KERNEL also sleeps. GFP_ATOMIC+yield() looks
weird, but it is no worse the implicit sleep inside GFP_KERNEL. Both could
loop endlessly under memory pressure.

CC: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
CC: David S. Miller <davem@davemloft.net>
CC: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-02 23:45:45 -07:00
Damian Lukowski
5152fc7de3 RTO connection timeout: coding style fixes and comments
This patch affects the retransmits_timed_out() function.

Changes:
1) Variables have more meaningful names
2) retransmits_timed_out() has an introductionary comment.
3) Small coding style changes.

Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-01 17:40:47 -07:00
Damian Lukowski
6fa12c8503 Revert Backoff [v3]: Calculate TCP's connection close threshold as a time value.
RFC 1122 specifies two threshold values R1 and R2 for connection timeouts,
which may represent a number of allowed retransmissions or a timeout value.
Currently linux uses sysctl_tcp_retries{1,2} to specify the thresholds
in number of allowed retransmissions.

For any desired threshold R2 (by means of time) one can specify tcp_retries2
(by means of number of retransmissions) such that TCP will not time out
earlier than R2. This is the case, because the RTO schedule follows a fixed
pattern, namely exponential backoff.

However, the RTO behaviour is not predictable any more if RTO backoffs can be
reverted, as it is the case in the draft
"Make TCP more Robust to Long Connectivity Disruptions"
(http://tools.ietf.org/html/draft-zimmermann-tcp-lcd).

In the worst case TCP would time out a connection after 3.2 seconds, if the
initial RTO equaled MIN_RTO and each backoff has been reverted.

This patch introduces a function retransmits_timed_out(N),
which calculates the timeout of a TCP connection, assuming an initial
RTO of MIN_RTO and N unsuccessful, exponentially backed-off retransmissions.

Whenever timeout decisions are made by comparing the retransmission counter
to some value N, this function can be used, instead.

The meaning of tcp_retries2 will be changed, as many more RTO retransmissions
can occur than the value indicates. However, it yields a timeout which is
similar to the one of an unpatched, exponentially backing off TCP in the same
scenario. As no application could rely on an RTO greater than MIN_RTO, there
should be no risk of a regression.

Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-01 02:45:47 -07:00
Damian Lukowski
f1ecd5d9e7 Revert Backoff [v3]: Revert RTO on ICMP destination unreachable
Here, an ICMP host/network unreachable message, whose payload fits to
TCP's SND.UNA, is taken as an indication that the RTO retransmission has
not been lost due to congestion, but because of a route failure
somewhere along the path.
With true congestion, a router won't trigger such a message and the
patched TCP will operate as standard TCP.

This patch reverts one RTO backoff, if an ICMP host/network unreachable
message, whose payload fits to TCP's SND.UNA, arrives.
Based on the new RTO, the retransmission timer is reset to reflect the
remaining time, or - if the revert clocked out the timer - a retransmission
is sent out immediately.
Backoffs are only reverted, if TCP is in RTO loss recovery, i.e. if
there have been retransmissions and reversible backoffs, already.

Changes from v2:
1) Renaming of skb in tcp_v4_err() moved to another patch.
2) Reintroduced tcp_bound_rto() and __tcp_set_rto().
3) Fixed code comments.

Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-01 02:45:42 -07:00
Eric Dumazet
df19a62677 tcp: keepalive cleanups
Introduce keepalive_probes(tp) helper, and use it, like 
keepalive_time_when(tp) and keepalive_intvl_when(tp)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-28 23:48:54 -07:00
John Dykstra
e3afe7b75e tcp: Fix MD5 signature checking on IPv4 mapped sockets
Fix MD5 signature checking so that an IPv4 active open
to an IPv6 socket can succeed.  In particular, use the
correct address family's signature generation function
for the SYN/ACK.

Reported-by:   Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: John Dykstra <john.dykstra1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 07:49:07 -07:00
David S. Miller
22f6dacdfc Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	include/net/tcp.h
2009-05-08 02:48:30 -07:00
Eric Dumazet
7aedec2ad5 tcp: tcp_prequeue() can use keyed wakeups
We can avoid waking up tasks not interested in receive notifications,
using wake_up_interruptible_poll() instead of wake_up_interruptible()

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-07 14:52:28 -07:00
Eric Dumazet
f5f8d86b23 tcp: tcp_prequeue() cleanup
Small cleanup patch to reduce line lengths, before a change in
tcp_prequeue().

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-07 14:52:26 -07:00
Satoru SATOH
0c266898b4 tcp: Fix tcp_prequeue() to get correct rto_min value
tcp_prequeue() refers to the constant value (TCP_RTO_MIN) regardless of
the actual value might be tuned. The following patches fix this and make
tcp_prequeue get the actual value returns from tcp_rto_min().

Signed-off-by: Satoru SATOH <satoru.satoh@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-04 11:11:01 -07:00
Florian Westphal
a0f82f64e2 syncookies: remove last_synq_overflow from struct tcp_sock
last_synq_overflow eats 4 or 8 bytes in struct tcp_sock, even
though it is only used when a listening sockets syn queue
is full.

We can (ab)use rx_opt.ts_recent_stamp to store the same information;
it is not used otherwise as long as a socket is in listen state.

Move linger2 around to avoid splitting struct mtu_probe
across cacheline boundary on 32 bit arches.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-20 02:25:26 -07:00
Ilpo Järvinen
797108d134 tcp: add helper for counter tweaking due mid-wq change
We need full-scale adjustment to fix a TCP miscount in the next
patch, so just move it into a helper and call for that from the
other places.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-02 16:31:44 -07:00
Ilpo Järvinen
0c54b85f28 tcp: simplify tcp_current_mss
There's very little need for most of the callsites to get
tp->xmit_goal_size updated. That will cost us divide as is,
so slice the function in two. Also, the only users of the
tp->xmit_goal_size are directly behind tcp_current_mss(),
so there's no need to store that variable into tcp_sock
at all! The drop of xmit_goal_size currently leaves 16-bit
hole and some reorganization would again be necessary to
change that (but I'm aiming to fill that hole with u16
xmit_goal_size_segs to cache the results of the remaining
divide to get that tso on regression).

Bring xmit_goal_size parts into tcp.c

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-15 20:09:54 -07:00
Ilpo Järvinen
c887e6d2d9 tcp: consolidate paws check
Wow, it was quite tricky to merge that stream of negations
but I think I finally got it right:

check & replace_ts_recent:
(s32)(rcv_tsval - ts_recent) >= 0                  => 0
(s32)(ts_recent - rcv_tsval) <= 0                  => 0

discard:
(s32)(ts_recent - rcv_tsval)  > TCP_PAWS_WINDOW    => 1
(s32)(ts_recent - rcv_tsval) <= TCP_PAWS_WINDOW    => 0

I toggled the return values of tcp_paws_check around since
the old encoding added yet-another negation making tracking
of truth-values really complicated.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-15 20:09:52 -07:00
Hantzis Fotis
ee7537b63a tcp: tcp_init_wl / tcp_update_wl argument cleanup
The above functions from include/net/tcp.h have been defined with an
argument that they never use. The argument is 'u32 ack' which is never
used inside the function body, and thus it can be removed. The rest of
the patch involves the necessary changes to the function callers of the
above two functions.

Signed-off-by: Hantzis Fotis <xantzis@ceid.upatras.gr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02 22:42:02 -08:00
Ilpo Järvinen
cabeccbd17 tcp: kill eff_sacks "cache", the sole user can calculate itself
Also fixes insignificant bug that would cause sending of stale
SACK block (would occur in some corner cases).

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02 03:00:16 -08:00
Ilpo Järvinen
758ce5c8d1 tcp: add helper for AI algorithm
It seems that implementation in yeah was inconsistent to what
other did as it would increase cwnd one ack earlier than the
others do.

Size benefits:

  bictcp_cong_avoid |  -36
  tcp_cong_avoid_ai |  +52
  bictcp_cong_avoid |  -34
  tcp_scalable_cong_avoid |  -36
  tcp_veno_cong_avoid |  -12
  tcp_yeah_cong_avoid |  -38

= -104 bytes total

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02 03:00:15 -08:00
Herbert Xu
bf296b125b tcp: Add GRO support
This patch adds the TCP-specific portion of GRO.  The criterion for
merging is extremely strict (the TCP header must match exactly apart
from the checksum) so as to allow refragmentation.  Otherwise this
is pretty much identical to LRO, except that we support the merging
of ECN packets.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-15 23:43:36 -08:00
Eric Dumazet
dd24c00191 net: Use a percpu_counter for orphan_count
Instead of using one atomic_t per protocol, use a percpu_counter
for "orphan_count", to reduce cache line contention on
heavy duty network servers. 

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 21:17:14 -08:00
Eric Dumazet
1748376b66 net: Use a percpu_counter for sockets_allocated
Instead of using one atomic_t per protocol, use a percpu_counter
for "sockets_allocated", to reduce cache line contention on
heavy duty network servers. 

Note : We revert commit (248969ae31
net: af_unix can make unix_nr_socks visbile in /proc),
since it is not anymore used after sock_prot_inuse_add() addition

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 21:16:35 -08:00
Ilpo Järvinen
8eecaba900 tcp: tcp_limit_reno_sacked can become static
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 13:45:29 -08:00
Ilpo Järvinen
832d11c5cd tcp: Try to restore large SKBs while SACK processing
During SACK processing, most of the benefits of TSO are eaten by
the SACK blocks that one-by-one fragment SKBs to MSS sized chunks.
Then we're in problems when cleanup work for them has to be done
when a large cumulative ACK comes. Try to return back to pre-split
state already while more and more SACK info gets discovered by
combining newly discovered SACK areas with the previous skb if
that's SACKed as well.

This approach has a number of benefits:

1) The processing overhead is spread more equally over the RTT
2) Write queue has less skbs to process (affect everything
   which has to walk in the queue past the sacked areas)
3) Write queue is consistent whole the time, so no other parts
   of TCP has to be aware of this (this was not the case with
   some other approach that was, well, quite intrusive all
   around).
4) Clean_rtx_queue can release most of the pages using single
   put_page instead of previous PAGE_SIZE/mss+1 calls

In case a hole is fully filled by the new SACK block, we attempt
to combine the next skb too which allows construction of skbs
that are even larger than what tso split them to and it handles
hole per on every nth patterns that often occur during slow start
overshoot pretty nicely. Though this to be really useful also
a retransmission would have to get lost since cumulative ACKs
advance one hole at a time in the most typical case.

TODO: handle upwards only merging. That should be rather easy
when segment is fully sacked but I'm leaving that as future
work item (it won't make very large difference anyway since
this current approach already covers quite a lot of normal
cases).

I was earlier thinking of some sophisticated way of tracking
timestamps of the first and the last segment but later on
realized that it won't be that necessary at all to store the
timestamp of the last segment. The cases that can occur are
basically either:
  1) ambiguous => no sensible measurement can be taken anyway
  2) non-ambiguous is due to reordering => having the timestamp
     of the last segment there is just skewing things more off
     than does some good since the ack got triggered by one of
     the holes (besides some substle issues that would make
     determining right hole/skb even harder problem). Anyway,
     it has nothing to do with this change then.

I choose to route some abnormal looking cases with goto noop,
some could be handled differently (eg., by stopping the
walking at that skb but again). In general, they either
shouldn't happen at all or are rare enough to make no difference
in practice.

In theory this change (as whole) could cause some macroscale
regression (global) because of cache misses that are taken over
the round-trip time but it gets very likely better because of much
less (local) cache misses per other write queue walkers and the
big recovery clearing cumulative ack.

Worth to note that these benefits would be very easy to get also
without TSO/GSO being on as long as the data is in pages so that
we can merge them. Currently I won't let that happen because
DSACK splitting at fragment that would mess up pcounts due to
sk_can_gso in tcp_set_skb_tso_segs. Once DSACKs fragments gets
avoided, we have some conditions that can be made less strict.

TODO: I will probably have to convert the excessive pointer
passing to struct sacktag_state... :-)

My testing revealed that considerable amount of skbs couldn't
be shifted because they were cloned (most likely still awaiting
tx reclaim)...

[The rest is considering future work instead since I got
repeatably EFAULT to tcpdump's recvfrom when I added
pskb_expand_head to deal with clones, so I separated that
into another, later patch]

...To counter that, I gave up on the fifth advantage:

5) When growing previous SACK block, less allocs for new skbs
   are done, basically a new alloc is needed only when new hole
   is detected and when the previous skb runs out of frags space

...which now only happens of if reclaim is fast enough to dispose
the clone before the SACK block comes in (the window is RTT long),
otherwise we'll have to alloc some.

With clones being handled I got these numbers (will be somewhat
worse without that), taken with fine-grained mibs:

                  TCPSackShifted 398
                   TCPSackMerged 877
            TCPSackShiftFallback 320
      TCPSACKCOLLAPSEFALLBACKGSO 0
  TCPSACKCOLLAPSEFALLBACKSKBBITS 0
  TCPSACKCOLLAPSEFALLBACKSKBDATA 0
    TCPSACKCOLLAPSEFALLBACKBELOW 0
    TCPSACKCOLLAPSEFALLBACKFIRST 1
 TCPSACKCOLLAPSEFALLBACKPREVBITS 318
      TCPSACKCOLLAPSEFALLBACKMSS 1
   TCPSACKCOLLAPSEFALLBACKNOHEAD 0
    TCPSACKCOLLAPSEFALLBACKSHIFT 0
          TCPSACKCOLLAPSENOOPSEQ 0
  TCPSACKCOLLAPSENOOPSMALLPCOUNT 0
     TCPSACKCOLLAPSENOOPSMALLLEN 0
             TCPSACKCOLLAPSEHOLE 12

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24 21:20:15 -08:00
Ilpo Järvinen
e1aa680fa4 tcp: move tcp_simple_retransmit to tcp_input
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24 21:11:55 -08:00
Petr Tesarik
38a7ddffa4 tcp: remove an unnecessary field in struct tcp_skb_cb
The urg_ptr field is not used anywhere and is merely confusing.

Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-13 22:44:11 -08:00
Peter Zijlstra
c57943a1c9 net: wrap sk->sk_backlog_rcv()
Wrap calling sk->sk_backlog_rcv() in a function. This will allow extending the
generic sk_backlog_rcv behaviour.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-07 14:18:42 -07:00
KOVACS Krisztian
a3116ac5c2 tcp: Port redirection support for TCP
Current TCP code relies on the local port of the listening socket
being the same as the destination address of the incoming
connection. Port redirection used by many transparent proxying
techniques obviously breaks this, so we have to store the original
destination port address.

This patch extends struct inet_request_sock and stores the incoming
destination port value there. It also modifies the handshake code to
use that value as the source port when sending reply packets.

Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-01 07:46:49 -07:00
David S. Miller
cd07a8ea0d tcp: Use SKB queue handling interfaces instead of by-hand versions.
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-23 00:50:13 -07:00
David S. Miller
d258b4914b tcp: Use skb_queue_is_last() instead of by-hand version.
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-23 00:34:37 -07:00
David S. Miller
43f59c8939 net: Remove __skb_insert() calls outside of skbuff internals.
This minor cleanup simplifies later changes which will convert
struct sk_buff and friends over to using struct list_head.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-21 21:28:51 -07:00
Ilpo Järvinen
ef9da47c7c tcp: don't clear retransmit_skb_hint when not necessary
Most importantly avoid doing it with cumulative ACK. Not clearing
means that we no longer need n^2 processing in resolution of each
fast recovery.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-20 21:25:15 -07:00
Ilpo Järvinen
0e1c54c2a4 tcp: reorganize retransmit code loops
Both loops are quite similar, so they can be combined
with little effort. As a result, forward_skb_hint becomes
obsolete as well.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-20 21:24:21 -07:00
Ilpo Järvinen
006f582c73 tcp: convert retransmit_cnt_hint to seqno
Main benefit in this is that we can then freely point
the retransmit_skb_hint to anywhere we want to because
there's no longer need to know what would be the count
changes involve, and since this is really used only as a
terminator, unnecessary work is one time walk at most,
and if some retransmissions are necessary after that
point later on, the walk is not full waste of time
anyway.

Since retransmit_high must be kept valid, all lost
markers must ensure that.

Now I also have learned how those "holes" in the
rexmittable skbs can appear, mtu probe does them. So
I removed the misleading comment as well.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-20 21:20:20 -07:00
Ilpo Järvinen
64edc2736e tcp: Partial hint clearing has again become meaningless
Ie., the difference between partial and all clearing doesn't
exists anymore since the SACK optimizations got dropped by
an sacktag rewrite.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-20 21:18:32 -07:00
Gerrit Renker
410e27a49b This reverts "Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/dccp_exp"
as it accentally contained the wrong set of patches. These will be
submitted separately.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-09 13:27:22 +02:00
Gerrit Renker
6224877b2c tcp/dccp: Consolidate common code for RFC 3390 conversion
This patch consolidates the code common to TCP and CCID-2:
 * TCP uses RFC 3390 in a packet-oriented manner (tcp_input.c) and
 * CCID-2 uses RFC 3390 in packet-oriented manner (RFC 4341).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04 07:45:39 +02:00
Adam Langley
33ad798c92 tcp: options clean up
This should fix the following bugs:
  * Connections with MD5 signatures produce invalid packets whenever SACK
    options are included
  * MD5 signatures are counted twice in the MSS calculations

Behaviour changes:
  * A SYN with MD5 + SACK + TS elicits a SYNACK with MD5 + SACK

    This is because we can't fit any SACK blocks in a packet with MD5 + TS
    options. There was discussion about disabling SACK rather than TS in
    order to fit in better with old, buggy kernels, but that was deemed to
    be unnecessary.

  * SYNs with MD5 don't include a TS option

    See above.

Additionally, it removes a bunch of duplicated logic for calculating options,
which should help avoid these sort of issues in the future.

Signed-off-by: Adam Langley <agl@imperialviolet.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-19 00:04:31 -07:00
Adam Langley
49a72dfb88 tcp: Fix MD5 signatures for non-linear skbs
Currently, the MD5 code assumes that the SKBs are linear and, in the case
that they aren't, happily goes off and hashes off the end of the SKB and
into random memory.

Reported by Stephen Hemminger in [1]. Advice thanks to Stephen and Evgeniy
Polyakov. Also includes a couple of missed route_caps from Stephen's patch
in [2].

[1] http://marc.info/?l=linux-netdev&m=121445989106145&w=2
[2] http://marc.info/?l=linux-netdev&m=121459157816964&w=2

Signed-off-by: Adam Langley <agl@imperialviolet.org>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-19 00:01:42 -07:00
Pavel Emelyanov
57ef42d59d mib: put tcp statistics on struct net
Proc temporary uses stats from init_net.

BTW, TCP_XXX_STATS are beautiful (w/o do { } while (0) facing) again :)

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-18 04:02:08 -07:00
Pavel Emelyanov
de0744af1f mib: add net to NET_INC_STATS_BH
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16 20:31:16 -07:00
Pavel Emelyanov
5c52ba170f sock: add net to prot->enter_memory_pressure callback
The tcp_enter_memory_pressure calls NET_INC_STATS, but doesn't
have where to get the net from.

I decided to add a sk argument, not the net itself, only to factor
all the required sock_net(sk) calls inside the enter_memory_pressure 
callback itself.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16 20:28:10 -07:00
Pavel Emelyanov
cf1100a7a4 mib: add net to TCP_ADD_STATS_USER
Now we're done with the TCP_XXX_STATS macros.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16 20:27:38 -07:00
Pavel Emelyanov
74688e487a mib: add net to TCP_DEC_STATS
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16 20:22:46 -07:00
Pavel Emelyanov
63231bddf6 mib: add net to TCP_INC_STATS_BH
Same as before - the sock is always there to get the net from,
but there are also some places with the net already saved on 
the stack.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16 20:22:25 -07:00
Pavel Emelyanov
81cc8a75d9 mib: add net to TCP_INC_STATS
Fortunately (almost) all the TCP code has a sock to get the net from :)

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16 20:22:04 -07:00
Pavel Emelyanov
a9c19329ec tcp: add net to tcp_mib_init
This one sets TCP MIBs after zeroing them, and thus requires
the net.

The existing single caller can use init_net (temporarily).

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16 20:21:42 -07:00
Pavel Emelyanov
f10f84314d mib: drop unused TCP_XXX_STATS macros
TCP_INC_STATS_USER and TCP_ADD_STATS_BH are currently unused.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16 20:21:20 -07:00
Brian Haley
7d06b2e053 net: change proto destroy method to return void
Change struct proto destroy function pointer to return void.  Noticed
by Al Viro.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-14 17:04:49 -07:00
David S. Miller
4ae127d1b6 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/smc911x.c
2008-06-13 20:52:39 -07:00
David S. Miller
ec0a196626 tcp: Revert 'process defer accept as established' changes.
This reverts two changesets, ec3c0982a2
("[TCP]: TCP_DEFER_ACCEPT updates - process as established") and
the follow-on bug fix 9ae27e0adb
("tcp: Fix slab corruption with ipv6 and tcp6fuzz").

This change causes several problems, first reported by Ingo Molnar
as a distcc-over-loopback regression where connections were getting
stuck.

Ilpo Järvinen first spotted the locking problems.  The new function
added by this code, tcp_defer_accept_check(), only has the
child socket locked, yet it is modifying state of the parent
listening socket.

Fixing that is non-trivial at best, because we can't simply just grab
the parent listening socket lock at this point, because it would
create an ABBA deadlock.  The normal ordering is parent listening
socket --> child socket, but this code path would require the
reverse lock ordering.

Next is a problem noticed by Vitaliy Gusev, he noted:

----------------------------------------
>--- a/net/ipv4/tcp_timer.c
>+++ b/net/ipv4/tcp_timer.c
>@@ -481,6 +481,11 @@ static void tcp_keepalive_timer (unsigned long data)
> 		goto death;
> 	}
>
>+	if (tp->defer_tcp_accept.request && sk->sk_state == TCP_ESTABLISHED) {
>+		tcp_send_active_reset(sk, GFP_ATOMIC);
>+		goto death;

Here socket sk is not attached to listening socket's request queue. tcp_done()
will not call inet_csk_destroy_sock() (and tcp_v4_destroy_sock() which should
release this sk) as socket is not DEAD. Therefore socket sk will be lost for
freeing.
----------------------------------------

Finally, Alexey Kuznetsov argues that there might not even be any
real value or advantage to these new semantics even if we fix all
of the bugs:

----------------------------------------
Hiding from accept() sockets with only out-of-order data only
is the only thing which is impossible with old approach. Is this really
so valuable? My opinion: no, this is nothing but a new loophole
to consume memory without control.
----------------------------------------

So revert this thing for now.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-12 16:34:35 -07:00
YOSHIFUJI Hideaki
9501f97229 tcp md5sig: Let the caller pass appropriate key for tcp_v{4,6}_do_calc_md5_hash().
As we do for other socket/timewait-socket specific parameters,
let the callers pass appropriate arguments to
tcp_v{4,6}_do_calc_md5_hash().

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
2008-06-12 03:46:30 +09:00
YOSHIFUJI Hideaki
8d26d76dd4 tcp md5sig: Share most of hash calcucaltion bits between IPv4 and IPv6.
We can share most part of the hash calculation code because
the only difference between IPv4 and IPv6 is their pseudo headers.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
2008-06-12 02:38:20 +09:00
YOSHIFUJI Hideaki
076fb72233 tcp md5sig: Remove redundant protocol argument.
Protocol is always TCP, so remove useless protocol argument.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
2008-06-12 02:38:19 +09:00
YOSHIFUJI Hideaki
7d5d5525bd tcp md5sig: Share MD5 Signature option parser between IPv4 and IPv6.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
2008-06-12 02:38:18 +09:00
Rami Rosen
45d465bc23 ipv4: Remove unused declaration from include/net/tcp.h.
- The tcp_unhash() method in /include/net/tcp.h is no more needed, as the
unhash method in tcp_prot structure is now inet_unhash (instead of
tcp_unhash in the
past); see tcp_prot structure in net/ipv4/tcp_ipv4.c.

- So, this patch removes tcp_unhash() declaration from include/net/tcp.h

Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-10 12:37:42 -07:00
John Heffner
dd9e0dda66 [TCP]: Increase the max_burst threshold from 3 to tp->reordering.
This change is necessary to allow cwnd to grow during persistent
reordering.  Cwnd moderation is applied when in the disorder state
and an ack that fills the hole comes in.  If the hole was greater
than 3 packets, but less than tp->reordering, cwnd will shrink when
it should not have.

Signed-off-by: John Heffner <jheffner@napa.(none)>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-16 02:29:56 -07:00
David S. Miller
df39e8ba56 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/ehea/ehea_main.c
	drivers/net/wireless/iwlwifi/Kconfig
	drivers/net/wireless/rt2x00/rt61pci.c
	net/ipv4/inet_timewait_sock.c
	net/ipv6/raw.c
	net/mac80211/ieee80211_sta.c
2008-04-14 02:30:23 -07:00
Gerrit Renker
7de6c03336 [SKB]: __skb_append = __skb_queue_after
This expresses __skb_append in terms of __skb_queue_after, exploiting that

  __skb_append(old, new, list) = __skb_queue_after(list, old, new).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-14 00:05:09 -07:00
Denis V. Lunev
5f4472c5a6 [TCP]: Remove owner from tcp_seq_afinfo.
Move it to tcp_seq_afinfo->seq_fops as should be.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-13 22:13:53 -07:00
Denis V. Lunev
68fcadd16c [TCP]: Place file operations directly into tcp_seq_afinfo.
No need to have separate never-used variable.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-13 22:13:30 -07:00
Denis V. Lunev
9427c4b36b [TCP]: Move seq_ops from tcp_iter_state to tcp_seq_afinfo.
No need to create seq_operations for each instance of 'netstat'.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-13 22:12:13 -07:00
Denis V. Lunev
a4146b1b2c [TCP]: Replace struct net on tcp_iter_state with seq_net_private.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-13 22:11:14 -07:00
Florian Westphal
4dfc281702 [Syncookies]: Add support for TCP options via timestamps.
Allow the use of SACK and window scaling when syncookies are used
and the client supports tcp timestamps. Options are encoded into
the timestamp sent in the syn-ack and restored from the timestamp
echo when the ack is received.

Based on earlier work by Glenn Griffin.
This patch avoids increasing the size of structs by encoding TCP
options into the least significant bits of the timestamp and
by not using any 'timestamp offset'.

The downside is that the timestamp sent in the packet after the synack
will increase by several seconds.

changes since v1:
 don't duplicate timestamp echo decoding function, put it into ipv4/syncookie.c
 and have ipv6/syncookies.c use it.
 Feedback from Glenn Griffin: fix line indented with spaces, kill redundant if ()

Reviewed-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-10 03:12:40 -07:00
Ilpo Järvinen
882bebaaca [TCP]: tcp_simple_retransmit can cause S+L
This fixes Bugzilla #10384

tcp_simple_retransmit does L increment without any checking
whatsoever for overflowing S+L when Reno is in use.

The simplest scenario I can currently think of is rather
complex in practice (there might be some more straightforward
cases though). Ie., if mss is reduced during mtu probing, it
may end up marking everything lost and if some duplicate ACKs
arrived prior to that sacked_out will be non-zero as well,
leading to S+L > packets_out, tcp_clean_rtx_queue on the next
cumulative ACK or tcp_fastretrans_alert on the next duplicate
ACK will fix the S counter.

More straightforward (but questionable) solution would be to
just call tcp_reset_reno_sack() in tcp_simple_retransmit but
it would negatively impact the probe's retransmission, ie.,
the retransmissions would not occur if some duplicate ACKs
had arrived.

So I had to add reno sacked_out reseting to CA_Loss state
when the first cumulative ACK arrives (this stale sacked_out
might actually be the explanation for the reports of left_out
overflows in kernel prior to 2.6.23 and S+L overflow reports
of 2.6.24). However, this alone won't be enough to fix kernel
before 2.6.24 because it is building on top of the commit
1b6d427bb7 ([TCP]: Reduce sacked_out with reno when purging
write_queue) to keep the sacked_out from overflowing.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Reported-by: Alessandro Suardi <alessandro.suardi@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-07 22:33:07 -07:00
Florian Westphal
2051f11fb8 [TCP]: Shrink syncookie_secret by 8 byte.
the first u32 copied from syncookie_secret is overwritten by the
minute-counter four lines below.  After adjusting the destination
address, the size of syncookie_secret can be reduced accordingly.

AFAICS, the only other user of syncookie_secret[] is the ipv6
syncookie support.  Because ipv6 syncookies only grab 44 bytes from
syncookie_secret[], this shouldn't affect them in any way.

With fixes from Glenn Griffin.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Glenn Griffin <ggriffin.kernel@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-23 22:21:28 -07:00
Patrick McManus
ec3c0982a2 [TCP]: TCP_DEFER_ACCEPT updates - process as established
Change TCP_DEFER_ACCEPT implementation so that it transitions a
connection to ESTABLISHED after handshake is complete instead of
leaving it in SYN-RECV until some data arrvies. Place connection in
accept queue when first data packet arrives from slow path.

Benefits:
  - established connection is now reset if it never makes it
   to the accept queue

 - diagnostic state of established matches with the packet traces
   showing completed handshake

 - TCP_DEFER_ACCEPT timeouts are expressed in seconds and can now be
   enforced with reasonable accuracy instead of rounding up to next
   exponential back-off of syn-ack retry.

Signed-off-by: Patrick McManus <mcmanus@ducksong.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-21 16:33:01 -07:00
Daniel Lezcano
6f8b13bcb3 [NETNS][IPV6] tcp6 - make proc per namespace
Make the proc for tcp6 to be per namespace.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-21 04:14:45 -07:00
Daniel Lezcano
f40c8174d3 [NETNS][IPV4] tcp - make proc handle the network namespaces
This patch, like udp proc, makes the proc functions to take care of
which namespace the socket belongs.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-21 04:13:54 -07:00
Glenn Griffin
c6aefafb7e [TCP]: Add IPv6 support to TCP SYN cookies
Updated to incorporate Eric's suggestion of using a per cpu buffer
rather than allocating on the stack.  Just a two line change, but will
resend in it's entirety.

Signed-off-by: Glenn Griffin <ggriffin.kernel@gmail.com>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
2008-03-04 15:18:21 +09:00
Denis V. Lunev
9b0f976f27 [INET]: Remove struct net_proto_family* from _init calls.
struct net_proto_family* is not used in icmp[v6]_init, ndisc_init,
igmp_init and tcp_v4_init. Remove it.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-02-29 11:13:15 -08:00
Ilpo Järvinen
cea14e0ed6 [TCP]: Uninline tcp_is_cwnd_limited
net/ipv4/tcp_cong.c:
  tcp_reno_cong_avoid |  -65
 1 function changed, 65 bytes removed, diff: -65

net/ipv4/arp.c:
  arp_ignore |   -5
 1 function changed, 5 bytes removed, diff: -5

net/ipv4/tcp_bic.c:
  bictcp_cong_avoid |  -57
 1 function changed, 57 bytes removed, diff: -57

net/ipv4/tcp_cubic.c:
  bictcp_cong_avoid |  -61
 1 function changed, 61 bytes removed, diff: -61

net/ipv4/tcp_highspeed.c:
  hstcp_cong_avoid |  -63
 1 function changed, 63 bytes removed, diff: -63

net/ipv4/tcp_hybla.c:
  hybla_cong_avoid |  -85
 1 function changed, 85 bytes removed, diff: -85

net/ipv4/tcp_htcp.c:
  htcp_cong_avoid |  -57
 1 function changed, 57 bytes removed, diff: -57

net/ipv4/tcp_veno.c:
  tcp_veno_cong_avoid |  -52
 1 function changed, 52 bytes removed, diff: -52

net/ipv4/tcp_scalable.c:
  tcp_scalable_cong_avoid |  -61
 1 function changed, 61 bytes removed, diff: -61

net/ipv4/tcp_yeah.c:
  tcp_yeah_cong_avoid |  -75
 1 function changed, 75 bytes removed, diff: -75

net/ipv4/tcp_illinois.c:
  tcp_illinois_cong_avoid |  -54
 1 function changed, 54 bytes removed, diff: -54

net/dccp/ccids/ccid3.c:
  ccid3_update_send_interval |   -7
  ccid3_hc_tx_packet_recv    |   +7
 2 functions changed, 7 bytes added, 7 bytes removed, diff: +0

net/ipv4/tcp_cong.c:
  tcp_is_cwnd_limited |  +88
 1 function changed, 88 bytes added, diff: +88

built-in.o:
 14 functions changed, 95 bytes added, 642 bytes removed, diff: -547

...Again some gcc artifacts visible as well.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 15:01:48 -08:00
Ilpo Järvinen
490d504693 [TCP]: Uninline tcp_set_state
net/ipv4/tcp.c:
  tcp_close_state | -226
  tcp_done        | -145
  tcp_close       | -564
  tcp_disconnect  | -141
 4 functions changed, 1076 bytes removed, diff: -1076

net/ipv4/tcp_input.c:
  tcp_fin               |  -86
  tcp_rcv_state_process | -164
 2 functions changed, 250 bytes removed, diff: -250

net/ipv4/tcp_ipv4.c:
  tcp_v4_connect | -209
 1 function changed, 209 bytes removed, diff: -209

net/ipv4/arp.c:
  arp_ignore |   +5
 1 function changed, 5 bytes added, diff: +5

net/ipv6/tcp_ipv6.c:
  tcp_v6_connect | -158
 1 function changed, 158 bytes removed, diff: -158

net/sunrpc/xprtsock.c:
  xs_sendpages |   -2
 1 function changed, 2 bytes removed, diff: -2

net/dccp/ccids/ccid3.c:
  ccid3_update_send_interval |   +7
 1 function changed, 7 bytes added, diff: +7

net/ipv4/tcp.c:
  tcp_set_state | +238
 1 function changed, 238 bytes added, diff: +238

built-in.o:
 12 functions changed, 250 bytes added, 1695 bytes removed, diff: -1445

I've no explanation why some unrelated changes seem to occur
consistently as well (arp_ignore, ccid3_update_send_interval;
I checked the arp_ignore asm and it seems to be due to some
reordered of operation order causing some extra opcodes to be
generated). Still, the benefits are pretty obvious from the
codiff's results.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 15:01:47 -08:00
Ilpo Järvinen
4828e7f49a [TCP]: Remove TCPCB_URG & TCPCB_AT_TAIL as unnecessary
The snd_up check should be enough. I suspect this has been
there to provide a minor optimization in clean_rtx_queue which
used to have a small if (!->sacked) block which could skip
snd_up check among the other work.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 15:00:23 -08:00
Ilpo Järvinen
90840defab [TCP]: Introduce tcp_wnd_end() to reduce line lengths
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 15:00:22 -08:00
Hideo Aoki
3ab224be6d [NET] CORE: Introducing new memory accounting interface.
This patch introduces new memory accounting functions for each network
protocol. Most of them are renamed from memory accounting functions
for stream protocols. At the same time, some stream memory accounting
functions are removed since other functions do same thing.

Renaming:
	sk_stream_free_skb()		->	sk_wmem_free_skb()
	__sk_stream_mem_reclaim()	->	__sk_mem_reclaim()
	sk_stream_mem_reclaim()		->	sk_mem_reclaim()
	sk_stream_mem_schedule 		->    	__sk_mem_schedule()
	sk_stream_pages()      		->	sk_mem_pages()
	sk_stream_rmem_schedule()	->	sk_rmem_schedule()
	sk_stream_wmem_schedule()	->	sk_wmem_schedule()
	sk_charge_skb()			->	sk_mem_charge()

Removeing
	sk_stream_rfree():	consolidates into sock_rfree()
	sk_stream_set_owner_r(): consolidates into skb_set_owner_r()
	sk_stream_mem_schedule()

The following functions are added.
    	sk_has_account(): check if the protocol supports accounting
	sk_mem_uncharge(): do the opposite of sk_mem_charge()

In addition, to achieve consolidation, updating sk_wmem_queued is
removed from sk_mem_charge().

Next, to consolidate memory accounting functions, this patch adds
memory accounting calls to network core functions. Moreover, present
memory accounting call is renamed to new accounting call.

Finally we replace present memory accounting calls with new interface
in TCP and SCTP.

Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Hideo Aoki <haoki@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 15:00:18 -08:00
YOSHIFUJI Hideaki
9cb5734e5b [TCP]: Convert several length variable to unsigned.
Several length variables cannot be negative, so convert int to
unsigned int.  This also allows us to do sane shift operations
on those variables.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:59:56 -08:00
Ilpo Järvinen
6859d49475 [TCP]: Abstract tp->highest_sack accessing & point to next skb
Pointing to the next skb is necessary to avoid referencing
already SACKed skbs which will soon be on a separate list.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:46 -08:00
Ilpo Järvinen
234b686070 [TCP]: Add tcp_for_write_queue_from_safe and use it in mtu_probe
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:43 -08:00
Ilpo Järvinen
c3a05c6050 [TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoid
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:41 -08:00
Ilpo Järvinen
8512430e55 [TCP]: Move FRTO checks out from write queue abstraction funcs
Better place exists in update_send_head (other non-queue related
adjustments are done there as well) which is the only caller of
tcp_advance_send_head (now that the bogus call from mtu_probe is
gone).

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:05 -08:00
Ilpo Järvinen
68f8353b48 [TCP]: Rewrite SACK block processing & sack_recv_cache use
Key points of this patch are:

  - In case new SACK information is advance only type, no skb
    processing below previously discovered highest point is done
  - Optimize cases below highest point too since there's no need
    to always go up to highest point (which is very likely still
    present in that SACK), this is not entirely true though
    because I'm dropping the fastpath_skb_hint which could
    previously optimize those cases even better. Whether that's
    significant, I'm not too sure.

Currently it will provide skipping by walking. Combined with
RB-tree, all skipping would become fast too regardless of window
size (can be done incrementally later).

Previously a number of cases in TCP SACK processing fails to
take advantage of costly stored information in sack_recv_cache,
most importantly, expected events such as cumulative ACK and new
hole ACKs. Processing on such ACKs result in rather long walks
building up latencies (which easily gets nasty when window is
huge). Those latencies are often completely unnecessary
compared with the amount of _new_ information received, usually
for cumulative ACK there's no new information at all, yet TCP
walks whole queue unnecessary potentially taking a number of
costly cache misses on the way, etc.!

Since the inclusion of highest_sack, there's a lot information
that is very likely redundant (SACK fastpath hint stuff,
fackets_out, highest_sack), though there's no ultimate guarantee
that they'll remain the same whole the time (in all unearthly
scenarios). Take advantage of this knowledge here and drop
fastpath hint and use direct access to highest SACKed skb as
a replacement.

Effectively "special cased" fastpath is dropped. This change
adds some complexity to introduce better coveraged "fastpath",
though the added complexity should make TCP behave more cache
friendly.

The current ACK's SACK blocks are compared against each cached
block individially and only ranges that are new are then scanned
by the high constant walk. For other parts of write queue, even
when in previously known part of the SACK blocks, a faster skip
function is used (if necessary at all). In addition, whenever
possible, TCP fast-forwards to highest_sack skb that was made
available by an earlier patch. In typical case, no other things
but this fast-forward and mandatory markings after that occur
making the access pattern quite similar to the former fastpath
"special case".

DSACKs are special case that must always be walked.

The local to recv_sack_cache copying could be more intelligent
w.r.t DSACKs which are likely to be there only once but that
is left to a separate patch.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:07 -08:00
Ilpo Järvinen
a47e5a988a [TCP]: Convert highest_sack to sk_buff to allow direct access
It is going to replace the sack fastpath hint quite soon... :-)

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:03 -08:00
Jens Axboe
9c55e01c0c [TCP]: Splice receive support.
Support for network splice receive.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:53:31 -08:00
Ilpo Jrvinen
6e42141009 [TCP] MTUprobe: fix potential sk_send_head corruption
When the abstraction functions got added, conversion here was
made incorrectly. As a result, the skb may end up pointing
to skb which got included to the probe skb and then was freed.
For it to trigger, however, skb_transmit must fail sending as
well.

Signed-off-by: Ilpo Jrvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-19 23:24:09 -08:00
Chuck Lever
c1bd24b768 [TCP]: Remove unneeded implicit type cast when calling tcp_minshall_update()
The tcp_minshall_update() function is called in exactly one place, and is
passed an unsigned integer for the mss_len argument.  Make the sign of the
argument match the sign of the passed variable in order to eliminate an
unneeded implicit type cast and a mixed sign comparison in
tcp_minshall_update().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-23 21:27:55 -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
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
6ff03ac355 [TCP]: tcp_packets_out_inc to tcp_output.c (no callers elsewhere)
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:48:28 -07:00
Ilpo Järvinen
e9144bd8da [TCP]: Remove unnecessary wrapper tcp_packets_out_dec
Makes caller side more obvious, there's no need to have
a wrapper for this oneliner!

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:48:27 -07:00
Ilpo Järvinen
e60402d0a9 [TCP]: Move sack_ok access to obviously named funcs & cleanup
Previously code had IsReno/IsFack defined as macros that were
local to tcp_input.c though sack_ok field has user elsewhere too
for the same purpose. This changes them to static inlines as
preferred according the current coding style and unifies the
access to sack_ok across multiple files. Magic bitops of sack_ok
for FACK and DSACK are also abstracted to functions with
appropriate names.

Note:
- One sack_ok = 1 remains but that's self explanary, i.e., it
  enables sack
- Couple of !IsReno cases are changed to tcp_is_sack
- There were no users for IsDSack => I dropped it

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:48:00 -07:00
Ilpo Järvinen
b9c4595bc4 [TCP]: Don't panic if S+L skb is detected
BUG_ON is an overkill. In fact, I was mislead by BUG_TRAP
severity (equals to WARN_ON) which is much lower than BUG_ON's
(that panics).

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:47:59 -07:00
Ilpo Järvinen
1b6d427bb7 [TCP]: Reduce sacked_out with reno when purging write_queue
Previously TCP had a transitional state during which reno
counted segments that are already below the current window into
sacked_out, which is now prevented. In addition, re-try now
the unconditional S+L skb catching.

This approach conservatively calls just remove_sack and leaves
reset_sack() calls alone. The best solution to the whole problem
would be to first calculate the new sacked_out fully (this patch
does not move reno_sack_reset calls from original sites and thus
does not implement this). However, that would require very
invasive change to fastretrans_alert (perhaps even slicing it to
two halves). Alternatively, all callers of tcp_packets_in_flight
(i.e., users that depend on sacked_out) should be postponed
until the new sacked_out has been calculated but it isn't any
simpler alternative.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:47:58 -07:00
Ilpo Järvinen
005903bc3a [TCP]: Left out sync->verify (the new meaning of it) & definify
Left_out was dropped a while ago, thus leaving verifying
consistency of the "left out" as only task for the function in
question. Thus make it's name more appropriate.

In addition, it is intentionally converted to #define instead
of static inline because the location of the invariant failure
is the most important thing to have if this ever triggers. I
think it would have been helpful e.g. in this case where the
location of the failure point had to be based on some quesswork:
    http://lkml.org/lkml/2007/5/2/464
...Luckily the guesswork seems to have proved to be correct.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:47:57 -07:00
Ilpo Järvinen
83ae40885f [TCP]: Add tcp_left_out(tp) "back" to get cleaner looking lines
tp->left_out got removed but nothing came to replace it back
then (users just did addition by themselves), so add function
for users now.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:47:56 -07:00
Ilpo Järvinen
b5860bbac7 [TCP]: Tighten tcp_sock's belt, drop left_out
It is easily calculable when needed and user are not that many
after all.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:47:55 -07:00
Ilpo Järvinen
af610b4ca1 [TCP]: Add tcp_dec_pcount_approx int variant
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:47:54 -07:00
Ilpo Järvinen
bdf1ee5d3b [TCP]: Move code from tcp_ecn.h to tcp*.c and tcp.h & remove it
No other users exist for tcp_ecn.h. Very few things remain in
tcp.h, for most TCP ECN functions callers reside within a
single .c file and can be placed there.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:47:54 -07:00
David S. Miller
f8ab18d2d9 [TCP]: Fix MD5 signature handling on big-endian.
Based upon a report and initial patch by Peter Lieven.

tcp4_md5sig_key and tcp6_md5sig_key need to start with
the exact same members as tcp_md5sig_key.  Because they
are both cast to that type by tcp_v{4,6}_md5_do_lookup().

Unfortunately tcp{4,6}_md5sig_key use a u16 for the key
length instead of a u8, which is what tcp_md5sig_key
uses.  This just so happens to work by accident on
little-endian, but on big-endian it doesn't.

Instead of casting, just place tcp_md5sig_key as the first member of
the address-family specific structures, adjust the access sites, and
kill off the ugly casts.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-28 15:18:35 -07:00
David S. Miller
3516ffb0fe [TCP]: Invoke tcp_sendmsg() directly, do not use inet_sendmsg().
As discovered by Evegniy Polyakov, if we try to sendmsg after
a connection reset, we can do incredibly stupid things.

The core issue is that inet_sendmsg() tries to autobind the
socket, but we should never do that for TCP.  Instead we should
just go straight into TCP's sendmsg() code which will do all
of the necessary state and pending socket error checks.

TCP's sendpage already directly vectors to tcp_sendpage(), so this
merely brings sendmsg() in line with that.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-02 19:42:28 -07:00
Stephen Hemminger
30cfd0baf0 [TCP]: congestion control API pass RTT in microseconds
This patch changes the API for the callback that is done after an ACK is
received. It solves a couple of issues:

  * Some congestion controls want higher resolution value of RTT
    (controlled by TCP_CONG_RTT_SAMPLE flag). These don't really want a ktime, but
    all compute a RTT in microseconds.

  * Other congestion control could use RTT at jiffies resolution.

To keep API consistent the units should be the same for both cases, just the
resolution should change.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-31 02:27:57 -07:00
Stephen Hemminger
16751347a0 [TCP]: remove unused argument to cong_avoid op
None of the existing TCP congestion controls use the rtt value pased
in the ca_ops->cong_avoid interface.  Which is lucky because seq_rtt
could have been -1 when handling a duplicate ack.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-18 01:46:58 -07:00
Pavel Emelianov
e4fd5da39f [TCP]: Consolidate checking for tcp orphan count being too big.
tcp_out_of_resources() and tcp_close() perform the
same checking of number of orphan sockets. Move this
code into common place.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-31 01:23:34 -07:00
Ilpo Järvinen
0ec96822d5 [TCP]: Use S+L catcher only with SACK for now
TCP has a transitional state when SACK is not in use during
which this invariant is temporarily broken. Without SACK,
tcp_clean_rtx_queue does not decrement sacked_out. Therefore
calls to tcp_sync_left_out before sacked_out is again
corrected by tcp_fastretrans_alert can trigger this trap as
sacked_out still has couple of segments that are already out
of window.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-03 03:30:34 -07:00
Ilpo Järvinen
d551e4541d [TCP] FRTO: RFC4138 allows Nagle override when new data must be sent
This is a corner case where less than MSS sized new data thingie
is awaiting in the send queue. For F-RTO to work correctly, a
new data segment must be sent at certain point or F-RTO cannot
be used at all. RFC4138 allows overriding of Nagle at that
point.

Implementation uses frto_counter states 2 and 3 to distinguish
when Nagle override is needed.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-30 00:58:16 -07:00
Ilpo Järvinen
34588b4c04 [TCP]: Catch skb with S+L bugs earlier
SACKED_ACKED and LOST are mutually exclusive with SACK, thus
having their sum larger than packets_out is bug with SACK.
Eventually these bugs trigger traps in the tcp_clean_rtx_queue
with SACK but it's much more informative to do this here.

Non-SACK TCP, however, could get more than packets_out duplicate
ACKs which each increment sacked_out, so it makes sense to do
this kind of limitting for non-SACK TCP but not for SACK enabled
one. Perhaps the author had the opposite in mind but did the
logic accidently wrong way around? Anyway, the sacked_out
incrementer code for non-SACK already deals this issue before
calling sync_left_out so this trapping can be done
unconditionally.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-30 00:57:33 -07:00
Stephen Hemminger
164891aadf [TCP]: Congestion control API update.
Do some simple changes to make congestion control API faster/cleaner.
* use ktime_t rather than timeval
* merge rtt sampling into existing ack callback
  this means one indirect call versus two per ack.
* use flags bits to store options/settings

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:29:45 -07:00
Ilpo Järvinen
9e412ba763 [TCP]: Sed magic converts func(sk, tp, ...) -> func(sk, ...)
This is (mostly) automated change using magic:

sed -e '/struct sock \*sk/ N' -e '/struct sock \*sk/ N'
    -e '/struct sock \*sk/ N' -e '/struct sock \*sk/ N'
    -e 's|struct sock \*sk,[\n\t ]*struct tcp_sock \*tp\([^{]*\n{\n\)|
	  struct sock \*sk\1\tstruct tcp_sock *tp = tcp_sk(sk);\n|g'
    -e 's|struct sock \*sk, struct tcp_sock \*tp|
	  struct sock \*sk|g' -e 's|sk, tp\([^-]\)|sk\1|g'

Fixed four unused variable (tp) warnings that were introduced.

In addition, manually added newlines after local variables and
tweaked function arguments positioning.

$ gcc --version
gcc (GCC) 4.1.1 20060525 (Red Hat 4.1.1-1)
...
$ codiff -fV built-in.o.old built-in.o.new
net/ipv4/route.c:
  rt_cache_flush |  +14
 1 function changed, 14 bytes added

net/ipv4/tcp.c:
  tcp_setsockopt |   -5
  tcp_sendpage   |  -25
  tcp_sendmsg    |  -16
 3 functions changed, 46 bytes removed

net/ipv4/tcp_input.c:
  tcp_try_undo_recovery |   +3
  tcp_try_undo_dsack    |   +2
  tcp_mark_head_lost    |  -12
  tcp_ack               |  -15
  tcp_event_data_recv   |  -32
  tcp_rcv_state_process |  -10
  tcp_rcv_established   |   +1
 7 functions changed, 6 bytes added, 69 bytes removed, diff: -63

net/ipv4/tcp_output.c:
  update_send_head          |   -9
  tcp_transmit_skb          |  +19
  tcp_cwnd_validate         |   +1
  tcp_write_wakeup          |  -17
  __tcp_push_pending_frames |  -25
  tcp_push_one              |   -8
  tcp_send_fin              |   -4
 7 functions changed, 20 bytes added, 63 bytes removed, diff: -43

built-in.o.new:
 18 functions changed, 40 bytes added, 178 bytes removed, diff: -138

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:29:34 -07:00
Andi Kleen
4ac02bab77 [TCP]: Uninline tcp_done().
The function is quite big and has several call sites and nothing
to collapse by compiler optimization on inlining.

Besides it's nicer to read in a in .c file.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:29:25 -07:00
Herbert Xu
604763722c [NET]: Treat CHECKSUM_PARTIAL as CHECKSUM_UNNECESSARY
When a transmitted packet is looped back directly, CHECKSUM_PARTIAL
maps to the semantics of CHECKSUM_UNNECESSARY.  Therefore we should
treat it as such in the stack.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:28:43 -07:00
Arnaldo Carvalho de Melo
aa8223c7bb [SK_BUFF]: Introduce tcp_hdr(), remove skb->h.th
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:25:26 -07:00
David S. Miller
fe067e8ab5 [TCP]: Abstract out all write queue operations.
This allows the write queue implementation to be changed,
for example, to one which allows fast interval searching.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:24:02 -07:00
James Morris
9d729f72dc [NET]: Convert xtime.tv_sec to get_seconds()
Where appropriate, convert references to xtime.tv_sec to the
get_seconds() helper function.

Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:23:32 -07:00
Ilpo Järvinen
3cfe3baaf0 [TCP]: Add two new spurious RTO responses to FRTO
New sysctl tcp_frto_response is added to select amongst these
responses:
	- Rate halving based; reuses CA_CWR state (default)
	- Very conservative; used to be the only one available (=1)
	- Undo cwr; undoes ssthresh and cwnd reductions (=2)

The response with rate halving requires a new parameter to
tcp_enter_cwr because FRTO has already reduced ssthresh and
doing a second reduction there has to be prevented. In addition,
to keep things nice on 80 cols screen, a local variable was
added.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:23:23 -07:00
John Heffner
886236c124 [TCP]: Add RFC3742 Limited Slow-Start, controlled by variable sysctl_tcp_max_ssthresh.
Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:23:19 -07:00
Ilpo Järvinen
46d0de4ed9 [TCP] FRTO: Entry is allowed only during (New)Reno like recovery
This interpretation comes from RFC4138:
    "If the sender implements some loss recovery algorithm other
     than Reno or NewReno [FHG04], the F-RTO algorithm SHOULD
     NOT be entered when earlier fast recovery is underway."

I think the RFC means to say (especially in the light of
Appendix B) that ...recovery is underway (not just fast recovery)
or was underway when it was interrupted by an earlier (F-)RTO
that hasn't yet been resolved (snd_una has not advanced enough).
Thus, my interpretation is that whenever TCP has ever
retransmitted other than head, basic version cannot be used
because then the order assumptions which are used as FRTO basis
do not hold.

NewReno has only the head segment retransmitted at a time.
Therefore, walk up to the segment that has not been SACKed, if
that segment is not retransmitted nor anything before it, we know
for sure, that nothing after the non-SACKed segment should be
either. This assumption is valid because TCPCB_EVER_RETRANS does
not leave holes but each non-SACKed segment is rexmitted
in-order.

Check for retrans_out > 1 avoids more expensive walk through the
skb list, as we can know the result beforehand: F-RTO will not be
allowed.

SACKed skb can turn into non-SACked only in the extremely rare
case of SACK reneging, in this case we might fail to detect
retransmissions if there were them for any other than head. To
get rid of that feature, whole rexmit queue would have to be
walked (always) or FRTO should be prevented when SACK reneging
happens. Of course RTO should still trigger after reneging which
makes this issue even less likely to show up. And as long as the
response is as conservative as it's now, nothing bad happens even
then.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:23:12 -07:00
Ilpo Järvinen
bdaae17da8 [TCP] FRTO: Moved tcp_use_frto from tcp.h to tcp_input.c
In addition, removed inline.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:23:02 -07:00
Frederik Deweerdt
ba7808eac1 [TCP]: remove tcp header from tcp_v4_check (take #2)
The tcphdr struct passed to tcp_v4_check is not used, the following
patch removes it from the parameter list.

This adds the netfilter modifications missing in the patch I sent
for rc3-mm1.

Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-08 12:38:44 -08:00
Gerrit Renker
0d630cc0a6 [TCP]: Use old definition of before
This reverts the new (unambiguous) definition of the TCP `before'
relation. As pointed out in an example by Herbert Xu, there is 
existing code which implicitly requires the old definition in order
to work correctly.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-01-04 12:25:16 -08:00
Gerrit Renker
9a036b9c33 [TCP]: Fix ambiguity in the `before' relation.
While looking at DCCP sequence numbers, I stumbled over a problem with
the following definition of before in tcp.h:

static inline int before(__u32 seq1, __u32 seq2)
{
        return (__s32)(seq1-seq2) < 0;
}

Problem: This definition suffers from an an ambiguity, i.e. always

           before(a, (a + 2^31) % 2^32)) = 1
           before((a + 2^31) % 2^32), a) = 1

         In text: when the difference between a and b amounts to 2^31,
         a is always considered `before' b, the function can not decide.
         The reason is that implicitly 0 is `before' 1 ... 2^31-1 ... 2^31

Solution: There is a simple fix, by defining before in such a way that
          0 is no longer `before' 2^31, i.e. 0 `before' 1 ... 2^31-1
          By not using the middle between 0 and 2^32, before can be made
          unambiguous.
          This is achieved by testing whether seq2-seq1 > 0 (using signed
          32-bit arithmetic).

I attach a patch to codify this. Also the `after' relation is basically
a redefinition of `before', it is now defined as a macro after before.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-22 11:12:01 -08:00
Al Viro
8e5200f540 [NET]: Fix assorted misannotations (from md5 and udplite merges).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:27:16 -08:00
Al Viro
b51655b958 [NET]: Annotate __skb_checksum_complete() and friends.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:23:38 -08:00
Al Viro
6b11687ef0 [NET]: Annotate csum_tcpudp_magic() callers in net/*
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:23:29 -08:00
YOSHIFUJI Hideaki
cfb6eeb4c8 [TCP]: MD5 Signature Option (RFC2385) support.
Based on implementation by Rick Payne.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:22:39 -08:00
Stephen Hemminger
ce7bc3bf15 [TCP]: Restrict congestion control choices.
Allow normal users to only choose among a restricted set of congestion
control choices.  The default is reno and what ever has been configured
as default. But the policy can be changed by administrator at any time.

For example, to allow any choice:
    cp /proc/sys/net/ipv4/tcp_available_congestion_control \
       /proc/sys/net/ipv4/tcp_allowed_congestion_control

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:21:49 -08:00
Stephen Hemminger
3ff825b28d [TCP]: Add tcp_available_congestion_control sysctl.
Create /proc/sys/net/ipv4/tcp_available_congestion_control
that reflects currently available TCP choices.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:21:48 -08:00
Eric Dumazet
72a3effaf6 [NET]: Size listen hash tables using backlog hint
We currently allocate a fixed size (TCP_SYNQ_HSIZE=512) slots hash table for
each LISTEN socket, regardless of various parameters (listen backlog for
example)

On x86_64, this means order-1 allocations (might fail), even for 'small'
sockets, expecting few connections. On the contrary, a huge server wanting a
backlog of 50000 is slowed down a bit because of this fixed limit.

This patch makes the sizing of listen hash table a dynamic parameter,
depending of :
- net.core.somaxconn tunable (default is 128)
- net.ipv4.tcp_max_syn_backlog tunable (default : 256, 1024 or 128)
- backlog value given by user application  (2nd parameter of listen())

For large allocations (bigger than PAGE_SIZE), we use vmalloc() instead of
kmalloc().

We still limit memory allocation with the two existing tunables (somaxconn &
tcp_max_syn_backlog). So for standard setups, this patch actually reduce RAM
usage.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:21:44 -08:00
Wei Yongjun
3687b1dc6f [TCP]: SNMPv2 tcpAttemptFails counter error
Refer to RFC2012, tcpAttemptFails is defined as following:
  tcpAttemptFails OBJECT-TYPE
      SYNTAX      Counter32
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
              "The number of times TCP connections have made a direct
              transition to the CLOSED state from either the SYN-SENT
              state or the SYN-RCVD state, plus the number of times TCP
              connections have made a direct transition to the LISTEN
              state from the SYN-RCVD state."
      ::= { tcp 7 }

When I lookup into RFC793, I found that the state change should occured
under following condition:
  1. SYN-SENT -> CLOSED
     a) Received ACK,RST segment when SYN-SENT state.

  2. SYN-RCVD -> CLOSED
     b) Received SYN segment when SYN-RCVD state(came from LISTEN).
     c) Received RST segment when SYN-RCVD state(came from SYN-SENT).
     d) Received SYN segment when SYN-RCVD state(came from SYN-SENT).

  3. SYN-RCVD -> LISTEN
     e) Received RST segment when SYN-RCVD state(came from LISTEN).

In my test, those direct state transition can not be counted to
tcpAttemptFails.

Signed-off-by: Wei Yongjun <yjwei@nanjing-fnst.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-08-02 13:38:19 -07:00
Herbert Xu
a430a43d08 [NET] gso: Fix up GSO packets with broken checksums
Certain subsystems in the stack (e.g., netfilter) can break the partial
checksum on GSO packets.  Until they're fixed, this patch allows this to
work by recomputing the partial checksums through the GSO mechanism.

Once they've all been converted to update the partial checksum instead of
clearing it, this workaround can be removed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-08 13:34:56 -07:00
Herbert Xu
bcd7611117 [NET]: Generalise TSO-specific bits from skb_setup_caps
This patch generalises the TSO-specific bits from sk_setup_caps by adding
the sk_gso_type member to struct sock.  This makes sk_setup_caps generic
so that it can be used by TCPv6 or UFO.

The only catch is that whoever uses this must provide a GSO implementation
for their protocol which I think is a fair deal :) For now UFO continues to
live without a GSO implementation which is OK since it doesn't use the sock
caps field at the moment.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-30 14:12:08 -07:00
Herbert Xu
576a30eb64 [NET]: Added GSO header verification
When GSO packets come from an untrusted source (e.g., a Xen guest domain),
we need to verify the header integrity before passing it to the hardware.

Since the first step in GSO is to verify the header, we can reuse that
code by adding a new bit to gso_type: SKB_GSO_DODGY.  Packets with this
bit set can only be fed directly to devices with the corresponding bit
NETIF_F_GSO_ROBUST.  If the device doesn't have that bit, then the skb
is fed to the GSO engine which will allow the packet to be sent to the
hardware if it passes the header check.

This patch changes the sg flag to a full features flag.  The same method
can be used to implement TSO ECN support.  We simply have to mark packets
with CWR set with SKB_GSO_ECN so that only hardware with a corresponding
NETIF_F_TSO_ECN can accept them.  The GSO engine can either fully segment
the packet, or segment the first MTU and pass the rest to the hardware for
further segmentation.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-29 16:57:53 -07:00
Herbert Xu
f4c50d990d [NET]: Add software TSOv4
This patch adds the GSO implementation for IPv4 TCP.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-23 02:07:33 -07:00
Herbert Xu
7967168cef [NET]: Merge TSO/UFO fields in sk_buff
Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not
going to scale if we add any more segmentation methods (e.g., DCCP).  So
let's merge them.

They were used to tell the protocol of a packet.  This function has been
subsumed by the new gso_type field.  This is essentially a set of netdev
feature bits (shifted by 16 bits) that are required to process a specific
skb.  As such it's easy to tell whether a given device can process a GSO
skb: you just have to and the gso_type field and the netdev's features
field.

I've made gso_type a conjunction.  The idea is that you have a base type
(e.g., SKB_GSO_TCPV4) that can be modified further to support new features.
For example, if we add a hardware TSO type that supports ECN, they would
declare NETIF_F_TSO | NETIF_F_TSO_ECN.  All TSO packets with CWR set would
have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO
packets would be SKB_GSO_TCPV4.  This means that only the CWR packets need
to be emulated in software.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-23 02:07:29 -07:00
Linus Torvalds
cee4cca740 Merge git://git.infradead.org/hdrcleanup-2.6
* git://git.infradead.org/hdrcleanup-2.6: (63 commits)
  [S390] __FD_foo definitions.
  Switch to __s32 types in joystick.h instead of C99 types for consistency.
  Add <sys/types.h> to headers included for userspace in <linux/input.h>
  Move inclusion of <linux/compat.h> out of user scope in asm-x86_64/mtrr.h
  Remove struct fddi_statistics from user view in <linux/if_fddi.h>
  Move user-visible parts of drivers/s390/crypto/z90crypt.h to include/asm-s390
  Revert include/media changes: Mauro says those ioctls are only used in-kernel(!)
  Include <linux/types.h> and use __uXX types in <linux/cramfs_fs.h>
  Use __uXX types in <linux/i2o_dev.h>, include <linux/ioctl.h> too
  Remove private struct dx_hash_info from public view in <linux/ext3_fs.h>
  Include <linux/types.h> and use __uXX types in <linux/affs_hardblocks.h>
  Use __uXX types in <linux/divert.h> for struct divert_blk et al.
  Use __u32 for elf_addr_t in <asm-powerpc/elf.h>, not u32. It's user-visible.
  Remove PPP_FCS from user view in <linux/ppp_defs.h>, remove __P mess entirely
  Use __uXX types in user-visible structures in <linux/nbd.h>
  Don't use 'u32' in user-visible struct ip_conntrack_old_tuple.
  Use __uXX types for S390 DASD volume label definitions which are user-visible
  S390 BIODASDREADCMB ioctl should use __u64 not u64 type.
  Remove unneeded inclusion of <linux/time.h> from <linux/ufs_fs.h>
  Fix private integer types used in V4L2 ioctls.
  ...

Manually resolve conflict in include/linux/mtd/physmap.h
2006-06-20 15:10:08 -07:00
David S. Miller
35089bb203 [TCP]: Add tcp_slow_start_after_idle sysctl.
A lot of people have asked for a way to disable tcp_cwnd_restart(),
and it seems reasonable to add a sysctl to do that.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:30:53 -07:00
Stephen Hemminger
72dc5b9225 [TCP]: Minimum congestion window consolidation.
Many of the TCP congestion methods all just use ssthresh
as the minimum congestion window on decrease.  Rather than
duplicating the code, just have that be the default if that
handle in the ops structure is not set.

Minor behaviour change to TCP compound.  It probably wants
to use this (ssthresh) as lower bound, rather than ssthresh/2
because the latter causes undershoot on loss.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:29:29 -07:00
Chris Leech
9593782585 [I/OAT]: Add a sysctl for tuning the I/OAT offloaded I/O threshold
Any socket recv of less than this ammount will not be offloaded

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:25:54 -07:00
Chris Leech
0e4b4992b8 [I/OAT]: Rename cleanup_rbuf to tcp_cleanup_rbuf and make non-static
Needed to be able to call tcp_cleanup_rbuf in tcp_input.c for I/OAT

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:25:50 -07:00
Chris Leech
97fc2f0848 [I/OAT]: Structure changes for TCP recv offload to I/OAT
Adds an async_wait_queue and some additional fields to tcp_sock, and a
dma_cookie_t to sk_buff.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:25:48 -07:00
David Woodhouse
62c4f0a2d5 Don't include linux/config.h from anywhere else in include/
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-04-26 12:56:16 +01:00
David S. Miller
0803dbed7a [TCP]: Kill unused extern decl for tcp_v4_hash_connecting()
Noticed by Alan Menegotto.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-31 02:25:46 -08:00
Dmitry Mishin
3fdadf7d27 [NET]: {get|set}sockopt compatibility layer
This patch extends {get|set}sockopt compatibility layer in order to
move protocol specific parts to their place and avoid huge universal
net/compat.c file in the future.

Signed-off-by: Dmitry Mishin <dim@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 22:45:21 -08:00
Rick Jones
15d99e02ba [TCP]: sysctl to allow TCP window > 32767 sans wscale
Back in the dark ages, we had to be conservative and only allow 15-bit
window fields if the window scale option was not negotiated.  Some
ancient stacks used a signed 16-bit quantity for the window field of
the TCP header and would get confused.

Those days are long gone, so we can use the full 16-bits by default
now.

There is a sysctl added so that we can still interact with such old
stacks

Signed-off-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 22:40:29 -08:00
John Heffner
5d424d5a67 [TCP]: MTU probing
Implementation of packetization layer path mtu discovery for TCP, based on
the internet-draft currently found at
<http://www.ietf.org/internet-drafts/draft-ietf-pmtud-method-05.txt>.

Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 17:53:41 -08:00
Stephen Hemminger
40efc6fa17 [TCP]: less inline's
TCP inline usage cleanup:
 * get rid of inline in several places
 * replace __inline__ with inline where possible
 * move functions used in one file out of tcp.h
 * let compiler decide on used once cases

On x86_64: 
   text	   data	    bss	    dec	    hex	filename
3594701	 648348	 567400	4810449	 4966d1	vmlinux.orig
3593133	 648580	 567400	4809113	 496199	vmlinux

On sparc64:
   text	   data	    bss	    dec	    hex	filename
2538278	 406152	 530392	3474822	 350586	vmlinux.ORIG
2536382	 406384	 530392	3473158	 34ff06	vmlinux

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 16:03:49 -08:00
Arnaldo Carvalho de Melo
8639a11e23 [TCP]: Don't use __constant_htonl for a non const arg
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:11:22 -08:00
Arnaldo Carvalho de Melo
6d6ee43e0b [TWSK]: Introduce struct timewait_sock_ops
So that we can share several timewait sockets related functions and
make the timewait mini sockets infrastructure closer to the request
mini sockets one.

Next changesets will take advantage of this, moving more code out of
TCP and DCCP v4 and v6 to common infrastructure.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:10:54 -08:00
Arnaldo Carvalho de Melo
8292a17a39 [ICSK]: Rename struct tcp_func to struct inet_connection_sock_af_ops
And move it to struct inet_connection_sock. DCCP will use it in the
upcoming changesets.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:10:38 -08:00
Stephen Hemminger
31f3426904 [TCP]: More spelling fixes.
From Joe Perches

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-15 15:17:10 -08:00
Stephen Hemminger
6a438bbe68 [TCP]: speed up SACK processing
Use "hints" to speed up the SACK processing. Various forms 
of this have been used by TCP developers (Web100, STCP, BIC)
to avoid the 2x linear search of outstanding segments.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10 17:14:59 -08:00
Stephen Hemminger
caa20d9abe [TCP]: spelling fixes
Minor spelling fixes for TCP code.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10 17:13:47 -08:00