I'm trying to use the TCP_MAXSEG option to setsockopt() to set the MSS
for both sides of a bidirectional connection.

man tcp says: "If this option is set before connection establishment, it
also changes the MSS value announced to the other end in the initial
packet."

However, the kernel only uses the MTU/route cache to set the advertised
MSS. That means if I set the MSS to, say, 500 before calling connect(),
I will send at most 500-byte packets, but I will still receive 1500-byte
packets in reply.

This is a bug, either in the kernel or the documentation.

This patch (applies to latest net-2.6) reduces the advertised value to
that requested by the user as long as setsockopt() is called before
connect() or accept(). This seems like the behavior that one would
expect as well as that which is documented.

I've tried to make sure that things that depend on the advertised MSS
are set correctly.
Signed-off-by: NTom Quetchenbach <virtualphtn@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If lost skb is sacked, we might have nothing to retransmit
as high as the retransmit_high is pointing to, so place
it lower to avoid unnecessary walking.

This is mainly for the case where high L'ed skbs gets sacked.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most importantly avoid doing it with cumulative ACK. However,
since we have lost_cnt_hint in the picture as well needing
adjustments, it's not as trivial as dealing with
retransmit_skb_hint (and cannot be done in the all place we
could trivially leave retransmit_skb_hint untouched).

With the previous patch, this should mostly remove O(n^2)
behavior while cumulative ACKs start flowing once rexmit
after a lossy round-trip made it through.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This doesn't much sense here afaict, probably never has. Since
fragmenting and collapsing deal the hints by themselves, there
should be very little reason for the rexmit loop to do that.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The validity of the retransmit_high must then be ensured
if no L'ed skb exits!

This makes a minor change to behavior, we now have to
iterate the head to find out that the loop terminates.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Because lost counter no longer requires tuning, this is
trivial to remove (the tuning wouldn't have been too
hard either) because no "new" retransmittable skb appeared
below retransmit_skb_hint when SACKing for sure.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I suspect it might have been related to the changed amount
of lost skbs, which was counted by retransmit_cnt_hint that
got changed.

The place for this clearing was very illogical anyway,
it should have been after the LOST-bit clearing loop to
make any sense.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This useful because we'd need to verifying soon in many places
which makes things slightly more complex than it used to be.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change __contant_htons() to htons() in the IPVS code when not in an
initializer.

-Brian
Signed-off-by: NBrian Haley <brian.haley@hp.com>
Acked-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

This teaches sparse that the following are not problems:

make C=1
  CHECK   net/ipv4/ipvs/ip_vs_ctl.c
net/ipv4/ipvs/ip_vs_ctl.c:1793:14: warning: context imbalance in 'ip_vs_info_seq_start' - wrong count at exit
net/ipv4/ipvs/ip_vs_ctl.c:1842:13: warning: context imbalance in 'ip_vs_info_seq_stop' - unexpected unlock
Acked-by: NSven Wegener <sven.wegener@stealer.net>
Acked-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

ip_vs_conn_new expects a union nf_inet_addr as the type for its address
parameters, not a plain integer.

This problem was detected by sparse.

make C=1
  CHECK   net/ipv4/ipvs/ip_vs_core.c
net/ipv4/ipvs/ip_vs_core.c:469:9: warning: Using plain integer as NULL pointer
Acked-by: NSven Wegener <sven.wegener@stealer.net>
Acked-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

Jumping to out unlocks __ip_vs_svc_lock, but that lock is not taken until
after code that may jump to out.

This problem was detected by sparse.

make C=1
  CHECK   net/ipv4/ipvs/ip_vs_ctl.c
net/ipv4/ipvs/ip_vs_ctl.c:1332:2: warning: context imbalance in 'ip_vs_edit_service' - unexpected unlock
Acked-by: NSven Wegener <sven.wegener@stealer.net>
Acked-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

as it accentally contained the wrong set of patches. These will be
submitted separately.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>

Instead of duplicating the fields, integrate a user stats structure into
the kernel stats structure. This is more robust when the members are
changed, because they are now automatically kept in sync.
Signed-off-by: NSven Wegener <sven.wegener@stealer.net>
Reviewed-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

Instead of checking the value in include/net/ip_vs.h, we can just
restrict the range in our Kconfig file. This will prevent values outside
of the range early.
Signed-off-by: NSven Wegener <sven.wegener@stealer.net>
Reviewed-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

Remove an incorrect ip_route_me_harder() that was probably a result of
merging my IPv6 patches with the local client patches. With this, IPv6+NAT
are working again.
Signed-off-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

Now that LVS can load balance locally generated traffic, packets may come
from the loopback device and thus may have a partial checksum.

The existing code allows for the case where there is no checksum at all for
TCP, however Herbert Xu has confirmed that this is not legal.
Signed-off-by: NSimon Horman <horms@verge.net.au>
Acked-by: NJulius Volz <juliusv@google.com>

How to reproduce ?
 - create a network namespace
 - use tcp protocol and get timewait socket
 - exit the network namespace
 - after a moment (when the timewait socket is destroyed), the kernel
   panics.

# BUG: unable to handle kernel NULL pointer dereference at
0000000000000007
IP: [<ffffffff821e394d>] inet_twdr_do_twkill_work+0x6e/0xb8
PGD 119985067 PUD 11c5c0067 PMD 0
Oops: 0000 [1] SMP
CPU 1
Modules linked in: ipv6 button battery ac loop dm_mod tg3 libphy ext3 jbd
edd fan thermal processor thermal_sys sg sata_svw libata dock serverworks
sd_mod scsi_mod ide_disk ide_core [last unloaded: freq_table]
Pid: 0, comm: swapper Not tainted 2.6.27-rc2 #3
RIP: 0010:[<ffffffff821e394d>] [<ffffffff821e394d>]
inet_twdr_do_twkill_work+0x6e/0xb8
RSP: 0018:ffff88011ff7fed0 EFLAGS: 00010246
RAX: ffffffffffffffff RBX: ffffffff82339420 RCX: ffff88011ff7ff30
RDX: 0000000000000001 RSI: ffff88011a4d03c0 RDI: ffff88011ac2fc00
RBP: ffffffff823392e0 R08: 0000000000000000 R09: ffff88002802a200
R10: ffff8800a5c4b000 R11: ffffffff823e4080 R12: ffff88011ac2fc00
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000041cbd940(0000) GS:ffff8800bff839c0(0000)
knlGS:0000000000000000
CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000007 CR3: 00000000bd87c000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 0, threadinfo ffff8800bff9e000, task
ffff88011ff76690)
Stack: ffffffff823392e0 0000000000000100 ffffffff821e3a3a
0000000000000008
0000000000000000 ffffffff821e3a61 ffff8800bff7c000 ffffffff8203c7e7
ffff88011ff7ff10 ffff88011ff7ff10 0000000000000021 ffffffff82351108
Call Trace:
<IRQ> [<ffffffff821e3a3a>] ? inet_twdr_hangman+0x0/0x9e
[<ffffffff821e3a61>] ? inet_twdr_hangman+0x27/0x9e
[<ffffffff8203c7e7>] ? run_timer_softirq+0x12c/0x193
[<ffffffff820390d1>] ? __do_softirq+0x5e/0xcd
[<ffffffff8200d08c>] ? call_softirq+0x1c/0x28
[<ffffffff8200e611>] ? do_softirq+0x2c/0x68
[<ffffffff8201a055>] ? smp_apic_timer_interrupt+0x8e/0xa9
[<ffffffff8200cad6>] ? apic_timer_interrupt+0x66/0x70
<EOI> [<ffffffff82011f4c>] ? default_idle+0x27/0x3b
[<ffffffff8200abbd>] ? cpu_idle+0x5f/0x7d


Code: e8 01 00 00 4c 89 e7 41 ff c5 e8 8d fd ff ff 49 8b 44 24 38 4c 89 e7
65 8b 14 25 24 00 00 00 89 d2 48 8b 80 e8 00 00 00 48 f7 d0 <48> 8b 04 d0
48 ff 40 58 e8 fc fc ff ff 48 89 df e8 c0 5f 04 00
RIP [<ffffffff821e394d>] inet_twdr_do_twkill_work+0x6e/0xb8
RSP <ffff88011ff7fed0>
CR2: 0000000000000007

This patch provides a function to purge all timewait sockets related
to a network namespace. The timewait sockets life cycle is not tied with
the network namespace, that means the timewait sockets stay alive while
the network namespace dies. The timewait sockets are for avoiding to
receive a duplicate packet from the network, if the network namespace is
freed, the network stack is removed, so no chance to receive any packets
from the outside world. Furthermore, having a pending destruction timer
on these sockets with a network namespace freed is not safe and will lead
to an oops if the timer callback which try to access data belonging to 
the namespace like for example in:
	inet_twdr_do_twkill_work
		-> NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITED);

Purging the timewait sockets at the network namespace destruction will:
 1) speed up memory freeing for the namespace
 2) fix kernel panic on asynchronous timewait destruction
Signed-off-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Acked-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is standard to use ipv6_addr_copy() to fill in
the in6 element of a union nf_inet_addr snet.

Thanks to Julius Volz for pointing this out.

Cc: Brian Haley <brian.haley@hp.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>
Acked-by: NJulius Volz <juliusv@google.com>

Sorry, this was my error.
Thanks to Julius Volz for pointing it out.
Signed-off-by: NSimon Horman <horms@verge.net.au>
Acked-by: NJulius Volz <juliusv@google.com>

We can't use non-local link-local addresses for destinations, without
knowing the interface on which we can reach the address. Reject them for
now.
Signed-off-by: NSven Wegener <sven.wegener@stealer.net>
Acked-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

They are only used in this file, so they should be static
Signed-off-by: NSven Wegener <sven.wegener@stealer.net>
Acked-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

Like the other code in this function does.
Signed-off-by: NSven Wegener <sven.wegener@stealer.net>
Acked-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

We want a pointer to it, not the value casted to a pointer.
Signed-off-by: NSven Wegener <sven.wegener@stealer.net>
Acked-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

This allows IPVS to load balance IPv6 connections made by a local process.
For example a proxy server running locally.

External client --> pound:443 -> Local:443 --> IPVS:80 --> RealServer

This is an extenstion to the IPv4 work done in this area
by Siim Põder and Malcolm Turnbull.

Cc: Siim Põder <siim@p6drad-teel.net>
Cc: Malcolm Turnbull <malcolm@loadbalancer.org>
Signed-off-by: NSimon Horman <horms@verge.net.au>

This allows IPVS to load balance connections made by a local process.
For example a proxy server running locally.

External client --> pound:443 -> Local:443 --> IPVS:80 --> RealServer
Signed-off-by: NSiim Põder <siim@p6drad-teel.net>
Signed-off-by: NMalcolm Turnbull <malcolm@loadbalancer.org>
Signed-off-by: NSimon Horman <horms@verge.net.au>

Allow adding IPv6 services through the genetlink interface and add checks
to see if the chosen scheduler is supported with IPv6 and whether the
supplied prefix length is sane. Make sure the service count exported via
the sockopt interface only counts IPv4 services.
Signed-off-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

Register the previously defined or adapted netfilter hook functions for
IPv6 as PF_INET6 hooks.
Signed-off-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

Adjust various debug outputs to use the new *_BUF macro variants for
correct output of v4/v6 addresses.
Signed-off-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

Add __ip_vs_addr_is_local_v6() to find out if an IPv6 address belongs to a
local interface. Use this function to decide whether to set the
IP_VS_CONN_F_LOCALNODE flag for IPv6 destinations.
Signed-off-by: NVince Busam <vbusam@google.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>