History log of /net/ipv4/inetpeer.c
Revision Date Author Comments
a7f26b7e1ee73ac9e766c430fea5af658d839954 09-Sep-2014 Willem de Bruijn <willemb@google.com> inet: remove dead inetpeer sequence code

inetpeer sequence numbers are no longer incremented, so no need to
check and flush the tree. The function that increments the sequence
number was already dead code and removed in in "ipv4: remove unused
function" (068a6e18). Remove the code that checks for a change, too.

Verifying that v4_seq and v6_seq are never incremented and thus that
flush_check compares bp->flush_seq to 0 is trivial.

The second part of the change removes flush_check completely even
though bp->flush_seq is exactly !0 once, at initialization. This
change is correct because the time this branch is true is when
bp->root == peer_avl_empty_rcu, in which the branch and
inetpeer_invalidate_tree are a NOOP.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
73f156a6e8c1074ac6327e0abd1169e95eb66463 02-Jun-2014 Eric Dumazet <edumazet@google.com> inetpeer: get rid of ip_id_count

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
is about 20.

4) If server deals with many tcp flows, we have a high probability of
not finding the inet_peer, allocating a fresh one, inserting it in
the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
851bdd11ca8b855ee946f50dac0850a4bec875c9 25-Apr-2014 xiao jin <jin.xiao@intel.com> inetpeer_gc_worker: trivial cleanup

Do not initialize list twice.
list_replace_init() already takes care of initializing list.
We don't need to initialize it with LIST_HEAD() beforehand.

Signed-off-by: xiao jin <jin.xiao@intel.com>
Reviewed-by: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
4e857c58efeb99393cba5a5d0d8ec7117183137c 17-Mar-2014 Peter Zijlstra <peterz@infradead.org> arch: Mass conversion of smp_mb__*()

Mostly scripted conversion of the smp_mb__* barriers.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
068a6e183484b1c619025da502a6fbfa53c50991 28-Dec-2013 Stephen Hemminger <stephen@networkplumber.org> ipv4: remove unused function

inetpeer_invalidate_family defined but never used

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
0c9a67d2ed028e0edd3260abafef4f1efd91aa5a 23-Dec-2013 Weilong Chen <chenweilong@huawei.com> ipv4: fix checkpatch error "space prohibited"

Signed-off-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
703133de331a7a7df47f31fb9de51dc6f68a9de8 19-Sep-2013 Ansis Atteka <aatteka@nicira.com> ip: generate unique IP identificator if local fragmentation is allowed

If local fragmentation is allowed, then ip_select_ident() and
ip_select_ident_more() need to generate unique IDs to ensure
correct defragmentation on the peer.

For example, if IPsec (tunnel mode) has to encrypt large skbs
that have local_df bit set, then all IP fragments that belonged
to different ESP datagrams would have used the same identificator.
If one of these IP fragments would get lost or reordered, then
peer could possibly stitch together wrong IP fragments that did
not belong to the same datagram. This would lead to a packet loss
or data corruption.

Signed-off-by: Ansis Atteka <aatteka@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bc9259a8bae9e814fc1f775a1b3effa13e6ad330 27-Sep-2012 Nicolas Dichtel <nicolas.dichtel@6wind.com> inetpeer: fix token initialization

When jiffies wraps around (for example, 5 minutes after the boot, see
INITIAL_JIFFIES) and peer has just been created, now - peer->rate_last can be
< XRLIM_BURST_FACTOR * timeout, so token is not set to the maximum value, thus
some icmp packets can be unexpectedly dropped.

Fix this case by initializing last_rate to 60 seconds in the past.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
203b42f7317494ae5e5efc7be6fb7f29c927f102 21-Aug-2012 Tejun Heo <tj@kernel.org> workqueue: make deferrable delayed_work initializer names consistent

Initalizers for deferrable delayed_work are confused.

* __DEFERRED_WORK_INITIALIZER()
* DECLARE_DEFERRED_WORK()
* INIT_DELAYED_WORK_DEFERRABLE()

Rename them to

* __DEFERRABLE_WORK_INITIALIZER()
* DECLARE_DEFERRABLE_WORK()
* INIT_DEFERRABLE_WORK()

This patch doesn't cause any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
5943634fc5592037db0693b261f7f4bea6bb9457 10-Jul-2012 David S. Miller <davem@davemloft.net> ipv4: Maintain redirect and PMTU info in struct rtable again.

Maintaining this in the inetpeer entries was not the right way to do
this at all.

Signed-off-by: David S. Miller <davem@davemloft.net>
81166dd6fa8eb780b2132d32fbc77eb6ac04e44e 10-Jul-2012 David S. Miller <davem@davemloft.net> tcp: Move timestamps from inetpeer to metrics cache.

With help from Lin Ming.

Signed-off-by: David S. Miller <davem@davemloft.net>
da55737467c1c3bc02271039c088171d82e0796f 20-Jun-2012 Eric Dumazet <edumazet@google.com> inetpeer: inetpeer_invalidate_tree() cleanup

No need to use cmpxchg() in inetpeer_invalidate_tree() since we hold
base lock.

Also use correct rcu annotations to remove sparse errors
(CONFIG_SPARSE_RCU_POINTER=y)

net/ipv4/inetpeer.c:144:19: error: incompatible types in comparison
expression (different address spaces)
net/ipv4/inetpeer.c:149:20: error: incompatible types in comparison
expression (different address spaces)
net/ipv4/inetpeer.c:595:10: error: incompatible types in comparison
expression (different address spaces)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
b48c80ece973e9eddb042f6685b482b261ff0d47 10-Jun-2012 David S. Miller <davem@davemloft.net> inet: Add family scope inetpeer flushes.

This implementation can deal with having many inetpeer roots, which is
a necessary prerequisite for per-FIB table rooted peer tables.

Each family (AF_INET, AF_INET6) has a sequence number which we bump
when we get a family invalidation request.

Each peer lookup cheaply checks whether the flush sequence of the
root we are using is out of date, and if so flushes it and updates
the sequence number.

Signed-off-by: David S. Miller <davem@davemloft.net>
c0efc887dcadbdbfe171f028acfab9c7c00e9dde 10-Jun-2012 David S. Miller <davem@davemloft.net> inet: Pass inetpeer root into inet_getpeer*() interfaces.

Otherwise we reference potentially non-existing members when
ipv6 is disabled.

Signed-off-by: David S. Miller <davem@davemloft.net>
56a6b248eb345c1948ee60bf426de1ff7dd81509 10-Jun-2012 David S. Miller <davem@davemloft.net> inet: Consolidate inetpeer_invalidate_tree() interfaces.

We only need one interface for this operation, since we always know
which inetpeer root we want to flush.

Signed-off-by: David S. Miller <davem@davemloft.net>
c3426b47190d7c6785230c91a706fd42208b4120 10-Jun-2012 David S. Miller <davem@davemloft.net> inet: Initialize per-netns inetpeer roots in net/ipv{4,6}/route.c

Instead of net/ipv4/inetpeer.c

Signed-off-by: David S. Miller <davem@davemloft.net>
c8a627ed06d6d49bf65015a2185c519335c4c83f 08-Jun-2012 Gao feng <gaofeng@cn.fujitsu.com> inetpeer: add namespace support for inetpeer

now inetpeer doesn't support namespace,the information will
be leaking across namespace.

this patch move the global vars v4_peers and v6_peers to
netns_ipv4 and netns_ipv6 as a field peers.

add struct pernet_operations inetpeer_ops to initial pernet
inetpeer data.

and change family_to_base and inet_getpeer to support namespace.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
55432d2b543a4b6dfae54f5c432a566877a85d90 05-Jun-2012 Eric Dumazet <edumazet@google.com> inetpeer: fix a race in inetpeer_gc_worker()

commit 5faa5df1fa2024 (inetpeer: Invalidate the inetpeer tree along with
the routing cache) added a race :

Before freeing an inetpeer, we must respect a RCU grace period, and make
sure no user will attempt to increase refcnt.

inetpeer_invalidate_tree() waits for a RCU grace period before inserting
inetpeer tree into gc_list and waking the worker. At that time, no
concurrent lookup can find a inetpeer in this tree.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ac3f48de09d8f4b73397047e413fadff7f65cfa7 06-Mar-2012 Steffen Klassert <steffen.klassert@secunet.com> route: Remove redirect_genid

As we invalidate the inetpeer tree along with the routing cache now,
we don't need a genid to reset the redirect handling when the routing
cache is flushed.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
5faa5df1fa2024bd750089ff21dcc4191798263d 06-Mar-2012 Steffen Klassert <steffen.klassert@secunet.com> inetpeer: Invalidate the inetpeer tree along with the routing cache

We initialize the routing metrics with the values cached on the
inetpeer in rt_init_metrics(). So if we have the metrics cached on the
inetpeer, we ignore the user configured fib_metrics.

To fix this issue, we replace the old tree with a fresh initialized
inet_peer_base. The old tree is removed later with a delayed work queue.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
10ec1bb7e9eb462548f14dd53c73e927a3ddf31c 17-Jan-2012 Dan Carpenter <dan.carpenter@oracle.com> inetpeer: initialize ->redirect_genid in inet_getpeer()

kmemcheck complains that ->redirect_genid doesn't get initialized.
Presumably it should be set to zero.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
747465ef7a082033e086dedc8189febfda43b015 16-Jan-2012 Eric Dumazet <eric.dumazet@gmail.com> net: fix some sparse errors

make C=2 CF="-D__CHECK_ENDIAN__" M=net

And fix flowi4_init_output() prototype for sport

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
6e5714eaf77d79ae1c8b47e3e040ff5411b717ec 04-Aug-2011 David S. Miller <davem@davemloft.net> net: Compute protocol sequence numbers and fragment IDs using MD5.

Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation. So the periodic
regeneration and 8-bit counter have been removed. We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.

Reported-by: Dan Kaminsky <dan@doxpara.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
87c48fa3b4630905f98268dde838ee43626a060c 22-Jul-2011 Eric Dumazet <eric.dumazet@gmail.com> ipv6: make fragment identifications less predictable

IPv6 fragment identification generation is way beyond what we use for
IPv4 : It uses a single generator. Its not scalable and allows DOS
attacks.

Now inetpeer is IPv6 aware, we can use it to provide a more secure and
scalable frag ident generator (per destination, instead of system wide)

This patch :
1) defines a new secure_ipv6_id() helper
2) extends inet_getid() to provide 32bit results
3) extends ipv6_select_ident() with a new dest parameter

Reported-by: Fernando Gont <fernando@gont.com.ar>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
6d1a3e042f55861a785527a35a6f1ab4217ee810 11-Jul-2011 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: kill inet_putpeer race

We currently can free inetpeer entries too early :

[ 782.636674] WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (f130f44c)
[ 782.636677] 1f7b13c100000000000000000000000002000000000000000000000000000000
[ 782.636686] i i i i u u u u i i i i u u u u i i i i u u u u u u u u u u u u
[ 782.636694] ^
[ 782.636696]
[ 782.636698] Pid: 4638, comm: ssh Not tainted 3.0.0-rc5+ #270 Hewlett-Packard HP Compaq 6005 Pro SFF PC/3047h
[ 782.636702] EIP: 0060:[<c13fefbb>] EFLAGS: 00010286 CPU: 0
[ 782.636707] EIP is at inet_getpeer+0x25b/0x5a0
[ 782.636709] EAX: 00000002 EBX: 00010080 ECX: f130f3c0 EDX: f0209d30
[ 782.636711] ESI: 0000bc87 EDI: 0000ea60 EBP: f0209ddc ESP: c173134c
[ 782.636712] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[ 782.636714] CR0: 8005003b CR2: f0beca80 CR3: 30246000 CR4: 000006d0
[ 782.636716] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[ 782.636717] DR6: ffff4ff0 DR7: 00000400
[ 782.636718] [<c13fbf76>] rt_set_nexthop.clone.45+0x56/0x220
[ 782.636722] [<c13fc449>] __ip_route_output_key+0x309/0x860
[ 782.636724] [<c141dc54>] tcp_v4_connect+0x124/0x450
[ 782.636728] [<c142ce43>] inet_stream_connect+0xa3/0x270
[ 782.636731] [<c13a8da1>] sys_connect+0xa1/0xb0
[ 782.636733] [<c13a99dd>] sys_socketcall+0x25d/0x2a0
[ 782.636736] [<c149deb8>] sysenter_do_call+0x12/0x28
[ 782.636738] [<ffffffff>] 0xffffffff

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
4b9d9be839fdb7dcd7ce7619a623fd9015a50cda 08-Jun-2011 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: remove unused list

Andi Kleen and Tim Chen reported huge contention on inetpeer
unused_peers.lock, on memcached workload on a 40 core machine, with
disabled route cache.

It appears we constantly flip peers refcnt between 0 and 1 values, and
we must insert/remove peers from unused_peers.list, holding a contended
spinlock.

Remove this list completely and perform a garbage collection on-the-fly,
at lookup time, using the expired nodes we met during the tree
traversal.

This removes a lot of code, makes locking more standard, and obsoletes
two sysctls (inet_peer_gc_mintime and inet_peer_gc_maxtime). This also
removes two pointers in inet_peer structure.

There is still a false sharing effect because refcnt is in first cache
line of object [were the links and keys used by lookups are located], we
might move it at the end of inet_peer structure to let this first cache
line mostly read by cpus.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Andi Kleen <andi@firstfloor.org>
CC: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
686a7e32ca7fdd819eb9606abd3db52b77d1479f 26-May-2011 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: fix race in unused_list manipulations

Several crashes in cleanup_once() were reported in recent kernels.

Commit d6cc1d642de9 (inetpeer: various changes) added a race in
unlink_from_unused().

One way to avoid taking unused_peers.lock before doing the list_empty()
test is to catch 0->1 refcnt transitions, using full barrier atomic
operations variants (atomic_cmpxchg() and atomic_inc_return()) instead
of previous atomic_inc() and atomic_add_unless() variants.

We then call unlink_from_unused() only for the owner of the 0->1
transition.

Add a new atomic_add_unless_return() static helper

With help from Arun Sharma.

Refs: https://bugzilla.kernel.org/show_bug.cgi?id=32772

Reported-by: Arun Sharma <asharma@fb.com>
Reported-by: Maximilian Engelhardt <maxi@daemonizer.de>
Reported-by: Yann Dupont <Yann.Dupont@univ-nantes.fr>
Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
66944e1c5797562cebe2d1857d46dff60bf9a69e 12-Apr-2011 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: reduce stack usage

On 64bit arches, we use 752 bytes of stack when cleanup_once() is called
from inet_getpeer().

Lets share the avl stack to save ~376 bytes.

Before patch :

# objdump -d net/ipv4/inetpeer.o | scripts/checkstack.pl

0x000006c3 unlink_from_pool [inetpeer.o]: 376
0x00000721 unlink_from_pool [inetpeer.o]: 376
0x00000cb1 inet_getpeer [inetpeer.o]: 376
0x00000e6d inet_getpeer [inetpeer.o]: 376
0x0004 inet_initpeers [inetpeer.o]: 112
# size net/ipv4/inetpeer.o
text data bss dec hex filename
5320 432 21 5773 168d net/ipv4/inetpeer.o

After patch :

objdump -d net/ipv4/inetpeer.o | scripts/checkstack.pl
0x00000c11 inet_getpeer [inetpeer.o]: 376
0x00000dcd inet_getpeer [inetpeer.o]: 376
0x00000ab9 peer_check_expire [inetpeer.o]: 328
0x00000b7f peer_check_expire [inetpeer.o]: 328
0x0004 inet_initpeers [inetpeer.o]: 112
# size net/ipv4/inetpeer.o
text data bss dec hex filename
5163 432 21 5616 15f0 net/ipv4/inetpeer.o

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Scot Doyle <lkml@scotdoyle.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Reviewed-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
4e75db2e8ff2c97762e87f61f54d7cdeaab1a6b0 14-Mar-2011 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: should use call_rcu() variant

After commit 7b46ac4e77f3224a (inetpeer: Don't disable BH for initial
fast RCU lookup.), we should use call_rcu() to wait proper RCU grace
period.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
46af31800b6916c92fffa529dc3c357008da957d 09-Mar-2011 Hiroaki SHIMODA <shimoda.hiroaki@gmail.com> ipv4: Fix PMTU update.

On current net-next-2.6, when Linux receives ICMP Type: 3, Code: 4
(Destination unreachable (Fragmentation needed)),

icmp_unreach
-> ip_rt_frag_needed
(peer->pmtu_expires is set here)
-> tcp_v4_err
-> do_pmtu_discovery
-> ip_rt_update_pmtu
(peer->pmtu_expires is already set,
so check_peer_pmtu is skipped.)
-> check_peer_pmtu

check_peer_pmtu is skipped and MTU is not updated.

To fix this, let check_peer_pmtu execute unconditionally.
And some minor fixes
1) Avoid potential peer->pmtu_expires set to be zero.
2) In check_peer_pmtu, argument of time_before is reversed.
3) check_peer_pmtu expects peer->pmtu_orig is initialized as zero,
but not initialized.

Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
7b46ac4e77f3224a1befe032c77f1df31d1b42c4 08-Mar-2011 David S. Miller <davem@davemloft.net> inetpeer: Don't disable BH for initial fast RCU lookup.

If modifications on other cpus are ok, then modifications to
the tree during lookup done by the local cpu are ok too.

Signed-off-by: David S. Miller <davem@davemloft.net>
65e8354ec13a45414045084166cb340c0d7ffe8a 04-Mar-2011 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: seqlock optimization

David noticed :

------------------
Eric, I was profiling the non-routing-cache case and something that
stuck out is the case of calling inet_getpeer() with create==0.

If an entry is not found, we have to redo the lookup under a spinlock
to make certain that a concurrent writer rebalancing the tree does
not "hide" an existing entry from us.

This makes the case of a create==0 lookup for a not-present entry
really expensive. It is on the order of 600 cpu cycles on my
Niagara2.

I added a hack to not do the relookup under the lock when create==0
and it now costs less than 300 cycles.

This is now a pretty common operation with the way we handle COW'd
metrics, so I think it's definitely worth optimizing.
-----------------

One solution is to use a seqlock instead of a spinlock to protect struct
inet_peer_base.

After a failed avl tree lookup, we can easily detect if a writer did
some changes during our lookup. Taking the lock and redo the lookup is
only necessary in this case.

Note: Add one private rcu_deref_locked() macro to place in one spot the
access to spinlock included in seqlock.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ddd4aa424b866a08ceba7ddf38e61542c91b93a0 10-Feb-2011 David S. Miller <davem@davemloft.net> inetpeer: Add redirect and PMTU discovery cached info.

Validity of the cached PMTU information is indicated by it's
expiration value being non-zero, just as per dst->expires.

The scheme we will use is that we will remember the pre-ICMP value
held in the metrics or route entry, and then at expiration time
we will restore that value.

In this way PMTU expiration does not kill off the cached route as is
done currently.

Redirect information is permanent, or at least until another redirect
is received.

Signed-off-by: David S. Miller <davem@davemloft.net>
7a71ed899e77cc822abb863e24a422dcf7e9fa33 09-Feb-2011 David S. Miller <davem@davemloft.net> inetpeer: Abstract address representation further.

Future changes will add caching information, and some of
these new elements will be addresses.

Since the family is implicit via the ->daddr.family member,
replicating the family in ever address we store is entirely
redundant.

Signed-off-by: David S. Miller <davem@davemloft.net>
92d8682926342d2b6aa5b2ecc02221e00e1573a0 05-Feb-2011 David S. Miller <davem@davemloft.net> inetpeer: Move ICMP rate limiting state into inet_peer entries.

Like metrics, the ICMP rate limiting bits are cached state about
a destination. So move it into the inet_peer entries.

If an inet_peer cannot be bound (the reason is memory allocation
failure or similar), the policy is to allow.

Signed-off-by: David S. Miller <davem@davemloft.net>
144001bddcb4db62c2261f1d703d835851031577 27-Jan-2011 David S. Miller <davem@davemloft.net> inetpeer: Mark metrics as "new" in fresh inetpeer entries.

Set the RTAX_LOCKED metric to INETPEER_METRICS_NEW (basically,
all ones) on fresh inetpeer entries.

This way code can determine if default metrics have been loaded
in from a routing table entry already.

Signed-off-by: David S. Miller <davem@davemloft.net>
3408404a4c2a4eead9d73b0bbbfe3f225b65f492 24-Jan-2011 David S. Miller <davem@davemloft.net> inetpeer: Use correct AVL tree base pointer in inet_getpeer().

Family was hard-coded to AF_INET but should be daddr->family.

This fixes crashes when unlinking ipv6 peer entries, since the
unlink code was looking up the base pointer properly.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8790ca172a1550949804a2ad59ccea310f680c9f 02-Dec-2010 David S. Miller <davem@davemloft.net> inetpeer: Kill use of inet_peer_address_t typedef.

They are verboten these days.

Signed-off-by: David S. Miller <davem@davemloft.net>
b3419363808f2481b24a817f491878e1795db4c7 30-Nov-2010 David S. Miller <davem@davemloft.net> ipv6: Add infrastructure to bind inet_peer objects to routes.

They are only allowed on cached ipv6 routes.

Signed-off-by: David S. Miller <davem@davemloft.net>
021e9299113363cc1b713f86b2cba30b8e6cb5dd 30-Nov-2010 David S. Miller <davem@davemloft.net> inetpeer: Add v6 peers tree, abstract root properly.

Add the ipv6 peer tree instance, and adapt remaining
direct references to 'v4_peers' as needed.

Signed-off-by: David S. Miller <davem@davemloft.net>
026630450244b8f8d1baf54548be0800aa1823ed 30-Nov-2010 David S. Miller <davem@davemloft.net> inetpeer: Abstract address comparisons.

Now v4 and v6 addresses will both work properly.

Signed-off-by: David S. Miller <davem@davemloft.net>
b534ecf1cd26f094497da6ae28a6ab64cdbe1617 30-Nov-2010 David S. Miller <davem@davemloft.net> inetpeer: Make inet_getpeer() take an inet_peer_adress_t pointer.

And make an inet_getpeer_v4() helper, update callers.

Signed-off-by: David S. Miller <davem@davemloft.net>
582a72da9a41be9227dc931d728ae2906880a589 30-Nov-2010 David S. Miller <davem@davemloft.net> inetpeer: Introduce inet_peer_address_t.

Currently only the v4 aspect is used, but this will change.

Signed-off-by: David S. Miller <davem@davemloft.net>
98158f5a853cafd33b254ae0eacc0dd69f90b93b 30-Nov-2010 David S. Miller <davem@davemloft.net> inetpeer: Abstract out the tree root accesses.

Instead of directly accessing "peer", change to code to
operate using a "struct inet_peer_base *" pointer.

This will facilitate the addition of a seperate tree for
ipv6 peer entries.

Signed-off-by: David S. Miller <davem@davemloft.net>
b914c4ea929a4ba6fb97967800dc473c31552b98 26-Oct-2010 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: __rcu annotations

Adds __rcu annotations to inetpeer
(struct inet_peer)->avl_left
(struct inet_peer)->avl_right

This is a tedious cleanup, but removes one smp_wmb() from link_to_pool()
since we now use more self documenting rcu_assign_pointer().

Note the use of RCU_INIT_POINTER() instead of rcu_assign_pointer() in
all cases we dont need a memory barrier.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
317fe0e6c5dc9448bcef41a2e31fecfd3dba7f55 16-Jun-2010 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: restore small inet_peer structures

Addition of rcu_head to struct inet_peer added 16bytes on 64bit arches.

Thats a bit unfortunate, since old size was exactly 64 bytes.

This can be solved, using an union between this rcu_head an four fields,
that are normally used only when a refcount is taken on inet_peer.
rcu_head is used only when refcnt=-1, right before structure freeing.

Add a inet_peer_refcheck() function to check this assertion for a while.

We can bring back SLAB_HWCACHE_ALIGN qualifier in kmem cache creation.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
5f2f89209500623ccb4713ec4af7de86fd30a9e4 16-Jun-2010 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: do not use zero refcnt for freed entries

Followup of commit aa1039e73cc2 (inetpeer: RCU conversion)

Unused inet_peer entries have a null refcnt.

Using atomic_inc_not_zero() in rcu lookups is not going to work for
them, and slow path is taken.

Fix this using -1 marker instead of 0 for deleted entries.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
aa1039e73cc2cf834e99c09d2033d5d2675357b9 15-Jun-2010 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: RCU conversion

inetpeer currently uses an AVL tree protected by an rwlock.

It's possible to make most lookups use RCU

1) Add a struct rcu_head to struct inet_peer

2) add a lookup_rcu_bh() helper to perform lockless and opportunistic
lookup. This is a normal function, not a macro like lookup().

3) Add a limit to number of links followed by lookup_rcu_bh(). This is
needed in case we fall in a loop.

4) add an smp_wmb() in link_to_pool() right before node insert.

5) make unlink_from_pool() use atomic_cmpxchg() to make sure it can take
last reference to an inet_peer, since lockless readers could increase
refcount, even while we hold peers.lock.

6) Delay struct inet_peer freeing after rcu grace period so that
lookup_rcu_bh() cannot crash.

7) inet_getpeer() first attempts lockless lookup.
Note this lookup can fail even if target is in AVL tree, but a
concurrent writer can let tree in a non correct form.
If this attemps fails, lock is taken a regular lookup is performed
again.

8) convert peers.lock from rwlock to a spinlock

9) Remove SLAB_HWCACHE_ALIGN when peer_cachep is created, because
rcu_head adds 16 bytes on 64bit arches, doubling effective size (64 ->
128 bytes)
In a future patch, this is probably possible to revert this part, if rcu
field is put in an union to share space with rid, ip_id_count, tcp_ts &
tcp_ts_stamp. These fields being manipulated only with refcnt > 0.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
d6cc1d642de9284cb26488ea390d915b50ee2504 14-Jun-2010 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: various changes

Try to reduce cache line contentions in peer management, to reduce IP
defragmentation overhead.

- peer_fake_node is marked 'const' to make sure its not modified.
(tested with CONFIG_DEBUG_RODATA=y)

- Group variables in two structures to reduce number of dirtied cache
lines. One named "peers" for avl tree root, its number of entries, and
associated lock. (candidate for RCU conversion)

- A second one named "unused_peers" for unused list and its lock

- Add a !list_empty() test in unlink_from_unused() to avoid taking lock
when entry is not unused.

- Use atomic_dec_and_lock() in inet_putpeer() to avoid taking lock in
some cases.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2c1409a0a2b88585ec0c03f1de0aafa178c56313 12-Nov-2009 Eric Dumazet <eric.dumazet@gmail.com> inetpeer: Optimize inet_getid()

While investigating for network latencies, I found inet_getid() was a
contention point for some workloads, as inet_peer_idlock is shared
by all inet_getid() users regardless of peers.

One way to fix this is to make ip_id_count an atomic_t instead
of __u16, and use atomic_add_return().

In order to keep sizeof(struct inet_peer) = 64 on 64bit arches
tcp_ts_stamp is also converted to __u32 instead of "unsigned long".

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
d9319100c1ad7d0ed4045ded767684ad25670436 03-Nov-2008 Jianjun Kong <jianjun@zeuux.org> net: clean up net/ipv4/ah4.c esp4.c fib_semantics.c inet_connection_sock.c inetpeer.c ip_output.c

Signed-off-by: Jianjun Kong <jianjun@zeuux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
0b040829952d84bf2a62526f0e24b624e0699447 11-Jun-2008 Adrian Bunk <bunk@kernel.org> net: remove CVS keywords

This patch removes CVS keywords that weren't updated for a long time
from comments.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
d71209ded2ba6010070d02005384897c59859d00 13-Nov-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Use list_head-s in inetpeer.c

The inetpeer.c tracks the LRU list of inet_perr-s, but makes
it by hands. Use the list_head-s for this.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
fc7b93800b48324667e218a4b6b784b853cf4dd7 21-Jul-2007 Patrick McHardy <kaber@trash.net> [IPV4]: Fix inetpeer gcc-4.2 warnings

CC net/ipv4/inetpeer.o
net/ipv4/inetpeer.c: In function 'unlink_from_pool':
net/ipv4/inetpeer.c:297: warning: the address of 'stack' will always evaluate as 'true'
net/ipv4/inetpeer.c:297: warning: the address of 'stack' will always evaluate as 'true'
net/ipv4/inetpeer.c: In function 'inet_getpeer':
net/ipv4/inetpeer.c:409: warning: the address of 'stack' will always evaluate as 'true'
net/ipv4/inetpeer.c:409: warning: the address of 'stack' will always evaluate as 'true'

"Fix" by checking for != NULL.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
20c2df83d25c6a95affe6157a4c9cac4cf5ffaac 20-Jul-2007 Paul Mundt <lethal@linux-sh.org> mm: Remove slab destructors from kmem_cache_create().

Slab destructors were no longer supported after Christoph's
c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been
BUGs for both slab and slub, and slob never supported them
either.

This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
243bbcaa09e8482aa28065cbc2eb99f0ca2fc8d6 07-Mar-2007 Eric Dumazet <dada1@cosmosbay.com> [IPV4]: Optimize inet_getpeer()

1) Some sysctl vars are declared __read_mostly

2) We can avoid updating stack[] when doing an AVL lookup only.

lookup() macro is extended to receive a second parameter, that may be NULL
in case of a pure lookup (no need to save the AVL path). This removes
unnecessary instructions, because compiler knows if this _stack parameter is
NULL or not.

text size of net/ipv4/inetpeer.o is 2063 bytes instead of 2107 on x86_64

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
cd354f1ae75e6466a7e31b727faede57a1f89ca5 14-Feb-2007 Tim Schmielau <tim@physik3.uni-rostock.de> [PATCH] remove many unneeded #includes of sched.h

After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
e18b890bb0881bbab6f4f1a6cd20d9c60d66b003 07-Dec-2006 Christoph Lameter <clameter@sgi.com> [PATCH] slab: remove kmem_cache_t

Replace all uses of kmem_cache_t with struct kmem_cache.

The patch was generated using the following script:

#!/bin/sh
#
# Replace one string by another in all the kernel sources.
#

set -e

for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
quilt add $file
sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
mv /tmp/$$ $file
quilt refresh
done

The script was run like this

sh replace kmem_cache_t "struct kmem_cache"

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
4663afe2c848e2abc8791202beecf40684f13eb4 13-Oct-2006 Eric Dumazet <dada1@cosmosbay.com> [NET]: reduce sizeof(struct inet_peer), cleanup, change in peer_check_expire()

1) shrink struct inet_peer on 64 bits platforms.
53576d9b995605a9edc7414b900a9218c8f23b1f 27-Sep-2006 Al Viro <viro@zeniv.linux.org.uk> [IPV4]: inetpeer annotations

This one is interesting - we use net-endian value as search key, but
order the tree by *host-endian* comparisons of keys. OK since we only
care about lookups. Annotated inet_getpeer() and friends.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
e5d679f33900c71d1a76ba07c5b04055abd34480 27-Aug-2006 Alexey Dobriyan <adobriyan@gmail.com> [NET]: Use SLAB_PANIC

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
7466d90f858ad89dda6f47b744e0a839937907a3 10-Jul-2006 Herbert Xu <herbert@gondor.apana.org.au> [IPV4] inetpeer: Get rid of volatile from peer_total

The variable peer_total is protected by a lock. The volatile marker
makes no sense. This shaves off 20 bytes on i386.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
09a626600b437d91f6b13ade5c7c4b374893c54e 09-Jan-2006 Kris Katterjohn <kjak@users.sourceforge.net> [NET]: Change some "if (x) BUG();" to "BUG_ON(x);"

This changes some simple "if (x) BUG();" statements to "BUG_ON(x);"

Signed-off-by: Kris Katterjohn <kjak@users.sourceforge.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
89cee8b1cbb9dac40c92ef1968aea2b45f82fd18 14-Dec-2005 Herbert Xu <herbert@gondor.apana.org.au> [IPV4]: Safer reassembly

Another spin of Herbert Xu's "safer ip reassembly" patch
for 2.6.16.

(The original patch is here:
http://marc.theaimsgroup.com/?l=linux-netdev&m=112281936522415&w=2
and my only contribution is to have tested it.)

This patch (optionally) does additional checks before accepting IP
fragments, which can greatly reduce the possibility of reassembling
fragments which originated from different IP datagrams.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arthur Kepner <akepner@sgi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8d06afab73a75f40ae2864e6c296356bab1ab473 09-Sep-2005 Ingo Molnar <mingo@elte.hu> [PATCH] timer initialization cleanup: DEFINE_TIMER

Clean up timer initialization by introducing DEFINE_TIMER a'la
DEFINE_SPINLOCK. Build and boot-tested on x86. A similar patch has been
been in the -RT tree for some time.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ba89966c1984513f4f2cc0a6c182266be44ddd03 26-Aug-2005 Eric Dumazet <dada1@cosmosbay.com> [NET]: use __read_mostly on kmem_cache_t , DEFINE_SNMP_STAT pointers

This patch puts mostly read only data in the right section
(read_mostly), to help sharing of these data between CPUS without
memory ping pongs.

On one of my production machine, tcp_statistics was sitting in a
heavily modified cache line, so *every* SNMP update had to force a
reload.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
20380731bc2897f2952ae055420972ded4cd786e 16-Aug-2005 Arnaldo Carvalho de Melo <acme@mandriva.com> [NET]: Fix sparse warnings

Of this type, mostly:

CHECK net/ipv6/netfilter.c
net/ipv6/netfilter.c:96:12: warning: symbol 'ipv6_netfilter_init' was not declared. Should it be static?
net/ipv6/netfilter.c:101:6: warning: symbol 'ipv6_netfilter_fini' was not declared. Should it be static?

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
0742fd53a3774781255bd1e471e7aa2e4a82d5f7 10-Aug-2005 Adrian Bunk <bunk@stusta.de> [IPV4]: possible cleanups

This patch contains the following possible cleanups:
- make needlessly global code static
- #if 0 the following unused global function:
- xfrm4_state.c: xfrm4_state_fini
- remove the following unneeded EXPORT_SYMBOL's:
- ip_output.c: ip_finish_output
- ip_output.c: sysctl_ip_default_ttl
- fib_frontend.c: ip_dev_find
- inetpeer.c: inet_peer_idlock
- ip_options.c: ip_options_compile
- ip_options.c: ip_options_undo
- net/core/request_sock.c: sysctl_max_syn_backlog

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
1344a41637114485fac7afa1505bce2ff862807a 23-Aug-2005 Dave Johnson <djohnson+linux-kernel@sw.starentnetworks.com> [IPV4]: Fix negative timer loop with lots of ipv4 peers.

From: Dave Johnson <djohnson+linux-kernel@sw.starentnetworks.com>

Found this bug while doing some scaling testing that created 500K inet
peers.

peer_check_expire() in net/ipv4/inetpeer.c isn't using inet_peer_gc_mintime
correctly and will end up creating an expire timer with less than the
minimum duration, and even zero/negative if enough active peers are
present.

If >65K peers, the timer will be less than inet_peer_gc_mintime, and with
>70K peers, the timer duration will reach zero and go negative.

The timer handler will continue to schedule another zero/negative timer in
a loop until peers can be aged. This can continue for at least a few
minutes or even longer if the peers remain active due to arriving packets
while the loop is occurring.

Bug is present in both 2.4 and 2.6. Same patch will apply to both just
fine.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 17-Apr-2005 Linus Torvalds <torvalds@ppc970.osdl.org> Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!