net: ipv4: Simplify the allocation of slab caches in inet_initpeers

commit 0a31bd5f2bbb ("KMEM_CACHE(): simplify slab cache creation")
introduces a new macro.
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240130092255.73078-1-chentao@kylinos.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

inetpeer: Fix data-races around sysctl.

While reading inetpeer sysctl variables, they can be changed
concurrently. So, we need to add READ_ONCE() to avoid data-races.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inetpeer: use div64_ul() and clamp_val() calculate inet_peer_threshold

In inet_initpeers(), struct inet_peer on IA32 uses 128 bytes in nowdays.
Get rid of the cascade and use div64_ul() and clamp_val() calculate that
will not need to be adjusted in the future as suggested by Eric Dumazet.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Yejune Deng <yejune.deng@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inetpeer: fix data-race in inet_putpeer / inet_putpeer

We need to explicitely forbid read/store tearing in inet_peer_gc()
and inet_putpeer().

The following syzbot report reminds us about inet_putpeer()
running without a lock held.

BUG: KCSAN: data-race in inet_putpeer / inet_putpeer

write to 0xffff888121fb2ed0 of 4 bytes by interrupt on cpu 0:
inet_putpeer+0x37/0xa0 net/ipv4/inetpeer.c:240
ip4_frag_free+0x3d/0x50 net/ipv4/ip_fragment.c:102
inet_frag_destroy_rcu+0x58/0x80 net/ipv4/inet_fragment.c:228
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch+0x256/0x5b0 kernel/rcu/tree.c:2157
rcu_core+0x369/0x4d0 kernel/rcu/tree.c:2377
rcu_core_si+0x12/0x20 kernel/rcu/tree.c:2386
__do_softirq+0x115/0x33f kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0xbb/0xe0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:536 [inline]
smp_apic_timer_interrupt+0xe6/0x280 arch/x86/kernel/apic/apic.c:1137
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
native_safe_halt+0xe/0x10 arch/x86/kernel/paravirt.c:71
arch_cpu_idle+0x1f/0x30 arch/x86/kernel/process.c:571
default_idle_call+0x1e/0x40 kernel/sched/idle.c:94
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x1af/0x280 kernel/sched/idle.c:263

write to 0xffff888121fb2ed0 of 4 bytes by interrupt on cpu 1:
inet_putpeer+0x37/0xa0 net/ipv4/inetpeer.c:240
ip4_frag_free+0x3d/0x50 net/ipv4/ip_fragment.c:102
inet_frag_destroy_rcu+0x58/0x80 net/ipv4/inet_fragment.c:228
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch+0x256/0x5b0 kernel/rcu/tree.c:2157
rcu_core+0x369/0x4d0 kernel/rcu/tree.c:2377
rcu_core_si+0x12/0x20 kernel/rcu/tree.c:2386
__do_softirq+0x115/0x33f kernel/softirq.c:292
run_ksoftirqd+0x46/0x60 kernel/softirq.c:603
smpboot_thread_fn+0x37d/0x4a0 kernel/smpboot.c:165
kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 4b9d9be839fd ("inetpeer: remove unused list")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: use a dedicated counter for icmp_v4 redirect packets

According to the algorithm described in the comment block at the
beginning of ip_rt_send_redirect, the host should try to send
'ip_rt_redirect_number' ICMP redirect packets with an exponential
backoff and then stop sending them at all assuming that the destination
ignores redirects.
If the device has previously sent some ICMP error packets that are
rate-limited (e.g TTL expired) and continues to receive traffic,
the redirect packets will never be transmitted. This happens since
peer->rate_tokens will be typically greater than 'ip_rt_redirect_number'
and so it will never be reset even if the redirect silence timeout
(ip_rt_redirect_silence) has elapsed without receiving any packet
requiring redirects.

Fix it by using a dedicated counter for the number of ICMP redirect
packets that has been sent by the host

I have not been able to identify a given commit that introduced the
issue since ip_rt_send_redirect implements the same rate-limiting
algorithm from commit 1da177e4c3f4 ("Linux-2.6.12-rc2")

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inetpeer: fix uninit-value in inet_getpeer

syzbot/KMSAN reported that p->dtime was read while it was
not yet initialized in :

delta = (__u32)jiffies - p->dtime;
if (delta < ttl || !refcount_dec_if_one(&p->refcnt))
gc_stack[i] = NULL;

This is a false positive, because the inetpeer wont be erased
from rb-tree if the refcount_dec_if_one(&p->refcnt) does not
succeed. And this wont happen before first inet_putpeer() call
for this inetpeer has been done, and ->dtime field is written
exactly before the refcount_dec_and_test(&p->refcnt).

The KMSAN report was :

BUG: KMSAN: uninit-value in inet_peer_gc net/ipv4/inetpeer.c:163 [inline]
BUG: KMSAN: uninit-value in inet_getpeer+0x1567/0x1e70 net/ipv4/inetpeer.c:228
CPU: 0 PID: 9494 Comm: syz-executor5 Not tainted 4.16.0+ #82
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x185/0x1d0 lib/dump_stack.c:53
kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
__msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
inet_peer_gc net/ipv4/inetpeer.c:163 [inline]
inet_getpeer+0x1567/0x1e70 net/ipv4/inetpeer.c:228
inet_getpeer_v4 include/net/inetpeer.h:110 [inline]
icmpv4_xrlim_allow net/ipv4/icmp.c:330 [inline]
icmp_send+0x2b44/0x3050 net/ipv4/icmp.c:725
ip_options_compile+0x237c/0x29f0 net/ipv4/ip_options.c:472
ip_rcv_options net/ipv4/ip_input.c:284 [inline]
ip_rcv_finish+0xda8/0x16d0 net/ipv4/ip_input.c:365
NF_HOOK include/linux/netfilter.h:288 [inline]
ip_rcv+0x119d/0x16f0 net/ipv4/ip_input.c:493
__netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
__netif_receive_skb net/core/dev.c:4627 [inline]
netif_receive_skb_internal+0x49d/0x630 net/core/dev.c:4701
netif_receive_skb+0x230/0x240 net/core/dev.c:4725
tun_rx_batched drivers/net/tun.c:1555 [inline]
tun_get_user+0x6d88/0x7580 drivers/net/tun.c:1962
tun_chr_write_iter+0x1d4/0x330 drivers/net/tun.c:1990
do_iter_readv_writev+0x7bb/0x970 include/linux/fs.h:1776
do_iter_write+0x30d/0xd40 fs/read_write.c:932
vfs_writev fs/read_write.c:977 [inline]
do_writev+0x3c9/0x830 fs/read_write.c:1012
SYSC_writev+0x9b/0xb0 fs/read_write.c:1085
SyS_writev+0x56/0x80 fs/read_write.c:1082
do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x455111
RSP: 002b:00007fae0365cba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 000000000000002e RCX: 0000000000455111
RDX: 0000000000000001 RSI: 00007fae0365cbf0 RDI: 00000000000000fc
RBP: 0000000020000040 R08: 00000000000000fc R09: 0000000000000000
R10: 000000000000002e R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000658 R14: 00000000006fc8e0 R15: 0000000000000000

Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188
kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314
kmem_cache_alloc+0xaab/0xb90 mm/slub.c:2756
inet_getpeer+0xed8/0x1e70 net/ipv4/inetpeer.c:210
inet_getpeer_v4 include/net/inetpeer.h:110 [inline]
ip4_frag_init+0x4d1/0x740 net/ipv4/ip_fragment.c:153
inet_frag_alloc net/ipv4/inet_fragment.c:369 [inline]
inet_frag_create net/ipv4/inet_fragment.c:385 [inline]
inet_frag_find+0x7da/0x1610 net/ipv4/inet_fragment.c:418
ip_find net/ipv4/ip_fragment.c:275 [inline]
ip_defrag+0x448/0x67a0 net/ipv4/ip_fragment.c:676
ip_check_defrag+0x775/0xda0 net/ipv4/ip_fragment.c:724
packet_rcv_fanout+0x2a8/0x8d0 net/packet/af_packet.c:1447
deliver_skb net/core/dev.c:1897 [inline]
deliver_ptype_list_skb net/core/dev.c:1912 [inline]
__netif_receive_skb_core+0x314a/0x4a80 net/core/dev.c:4545
__netif_receive_skb net/core/dev.c:4627 [inline]
netif_receive_skb_internal+0x49d/0x630 net/core/dev.c:4701
netif_receive_skb+0x230/0x240 net/core/dev.c:4725
tun_rx_batched drivers/net/tun.c:1555 [inline]
tun_get_user+0x6d88/0x7580 drivers/net/tun.c:1962
tun_chr_write_iter+0x1d4/0x330 drivers/net/tun.c:1990
do_iter_readv_writev+0x7bb/0x970 include/linux/fs.h:1776
do_iter_write+0x30d/0xd40 fs/read_write.c:932
vfs_writev fs/read_write.c:977 [inline]
do_writev+0x3c9/0x830 fs/read_write.c:1012
SYSC_writev+0x9b/0xb0 fs/read_write.c:1085
SyS_writev+0x56/0x80 fs/read_write.c:1082
do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: make kmem caches as __ro_after_init

All kmem caches aren't reallocated once set up.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inetpeer: speed up inetpeer_invalidate_tree()

As measured in my prior patch ("sch_netem: faster rb tree removal"),
rbtree_postorder_for_each_entry_safe() is nice looking but much slower
than using rb_next() directly, except when tree is small enough
to fit in CPU caches (then the cost is the same)

From: Eric Dumazet <edumazet@google.com>

Signed-off-by: David S. Miller <davem@davemloft.net>

inetpeer: fix RCU lookup() again

My prior fix was not complete, as we were dereferencing a pointer
three times per node, not twice as I initially thought.

Fixes: 4cc5b44b29a9 ("inetpeer: fix RCU lookup()")
Fixes: b145425f269a ("inetpeer: remove AVL implementation in favor of RB tree")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inetpeer: fix RCU lookup()

Excess of seafood or something happened while I cooked the commit
adding RB tree to inetpeer.

Of course, RCU rules need to be respected or bad things can happen.

In this particular loop, we need to read *pp once per iteration, not
twice.

Fixes: b145425f269a ("inetpeer: remove AVL implementation in favor of RB tree")
Reported-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inetpeer: remove AVL implementation in favor of RB tree

As discussed in Faro during Netfilter Workshop 2017, RB trees can be
used with RCU, using a seqlock.

Note that net/rxrpc/conn_service.c is already using this.

This patch converts inetpeer from AVL tree to RB tree, since it allows
to remove private AVL implementation in favor of shared RB code.

$ size net/ipv4/inetpeer.before net/ipv4/inetpeer.after
text data bss dec hex filename
3195 40 128 3363 d23 net/ipv4/inetpeer.before
1562 24 0 1586 632 net/ipv4/inetpeer.after

The same technique can be used to speed up
net/netfilter/nft_set_rbtree.c (removing rwlock contention in fast path)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: convert inet_peer.refcnt from atomic_t to refcount_t

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
This conversion requires overall +1 on the whole
refcounting scheme.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add helper function to compare inetpeer addresses

tcp_metrics and inetpeer both have functions to compare inetpeer
addresses. Consolidate into 1 version.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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>

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>

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>

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>

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>

ipv4: fix checkpatch error "space prohibited"

Signed-off-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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>

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>

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>

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>

tcp: Move timestamps from inetpeer to metrics cache.

With help from Lin Ming.

Signed-off-by: David S. Miller <davem@davemloft.net>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

inetpeer: Kill use of inet_peer_address_t typedef.

They are verboten these days.

Signed-off-by: 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>

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>

inetpeer: Abstract address comparisons.

Now v4 and v6 addresses will both work properly.

Signed-off-by: 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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

[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>

[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>

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>

[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>

[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>

[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>

[NET]: reduce sizeof(struct inet_peer), cleanup, change in peer_check_expire()

1) shrink struct inet_peer on 64 bits platforms.

[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>

[NET]: Use SLAB_PANIC

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[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>

[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>

[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>

[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>

[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>

[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>

[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>

[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>

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!