Commit graph

102 commits

Author SHA1 Message Date
Florian Westphal
d157bd7615 netfilter: x_tables: check for size overflow
Ben Hawkes says:
 integer overflow in xt_alloc_table_info, which on 32-bit systems can
 lead to small structure allocation and a copy_from_user based heap
 corruption.

Reported-by: Ben Hawkes <hawkes@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-12 11:55:01 +01:00
Florian Westphal
b9e69e1273 netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.

Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.

When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.

This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.

In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).

Thanks to Eric Biederman, hooks are no longer global, but per namespace.

This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.

We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.

If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.

Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-02 20:05:24 +01:00
Philip Whineray
f13f2aeed1 netfilter: Set /proc/net entries owner to root in namespace
Various files are owned by root with 0440 permission. Reading them is
impossible in an unprivileged user namespace, interfering with firewall
tools. For instance, iptables-save relies on /proc/net/ip_tables_names
contents to dump only loaded tables.

This patch assigned ownership of the following files to root in the
current namespace:

- /proc/net/*_tables_names
- /proc/net/*_tables_matches
- /proc/net/*_tables_targets
- /proc/net/nf_conntrack
- /proc/net/nf_conntrack_expect
- /proc/net/netfilter/nfnetlink_log

A mapping for root must be available, so this order should be followed:

unshare(CLONE_NEWUSER);
/* Setup the mapping */
unshare(CLONE_NEWNET);

Signed-off-by: Philip Whineray <phil@firehol.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-11-25 13:54:09 +01:00
Florian Westphal
2ffbceb2b0 netfilter: remove hook owner refcounting
since commit 8405a8fff3 ("netfilter: nf_qeueue: Drop queue entries on
nf_unregister_hook") all pending queued entries are discarded.

So we can simply remove all of the owner handling -- when module is
removed it also needs to unregister all its hooks.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-16 18:21:39 +02:00
Florian Westphal
dcebd3153e netfilter: add and use jump label for xt_tee
Don't bother testing if we need to switch to alternate stack
unless TEE target is used.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-15 18:18:06 +02:00
Florian Westphal
7814b6ec6d netfilter: xtables: don't save/restore jumpstack offset
In most cases there is no reentrancy into ip/ip6tables.

For skbs sent by REJECT or SYNPROXY targets, there is one level
of reentrancy, but its not relevant as those targets issue an absolute
verdict, i.e. the jumpstack can be clobbered since its not used
after the target issues absolute verdict (ACCEPT, DROP, STOLEN, etc).

So the only special case where it is relevant is the TEE target, which
returns XT_CONTINUE.

This patch changes ip(6)_do_table to always use the jump stack starting
from 0.

When we detect we're operating on an skb sent via TEE (percpu
nf_skb_duplicated is 1) we switch to an alternate stack to leave
the original one alone.

Since there is no TEE support for arptables, it doesn't need to
test if tee is active.

The jump stack overflow tests are no longer needed as well --
since ->stacksize is the largest call depth we cannot exceed it.

A much better alternative to the external jumpstack would be to just
declare a jumps[32] stack on the local stack frame, but that would mean
we'd have to reject iptables rulesets that used to work before.

Another alternative would be to start rejecting rulesets with a larger
call depth, e.g. 1000 -- in this case it would be feasible to allocate the
entire stack in the percpu area which would avoid one dereference.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-15 18:18:06 +02:00
Florian Westphal
98d1bd802c netfilter: xtables: compute exact size needed for jumpstack
The {arp,ip,ip6tables} jump stack is currently sized based
on the number of user chains.

However, its rather unlikely that every user defined chain jumps to the
next, so lets use the existing loop detection logic to also track the
chain depths.

The stacksize is then set to the largest chain depth seen.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-15 18:18:04 +02:00
Eric Dumazet
711bdde6a8 netfilter: x_tables: remove XT_TABLE_INFO_SZ and a dereference.
After Florian patches, there is no need for XT_TABLE_INFO_SZ anymore :
Only one copy of table is kept, instead of one copy per cpu.

We also can avoid a dereference if we put table data right after
xt_table_info. It reduces register pressure and helps compiler.

Then, we attempt a kmalloc() if total size is under order-3 allocation,
to reduce TLB pressure, as in many cases, rules fit in 32 KB.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-06-15 20:19:20 +02:00
Florian Westphal
482cfc3185 netfilter: xtables: avoid percpu ruleset duplication
We store the rule blob per (possible) cpu.  Unfortunately this means we can
waste lot of memory on big smp machines. ipt_entry structure ('rule head')
is 112 byte, so e.g. with maxcpu=64 one single rule eats
close to 8k RAM.

Since previous patch made counters percpu it appears there is nothing
left in the rule blob that needs to be percpu.

On my test system (144 possible cpus, 400k dummy rules) this
change saves close to 9 Gigabyte of RAM.

Reported-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-06-12 14:27:10 +02:00
Joe Perches
861fb1078f netfilter: Use correct return for seq_show functions
Using seq_has_overflowed doesn't produce the right return value.
Either 0 or -1 is, but 0 is much more common and works well when
seq allocation retries.

I believe this doesn't matter as the initial allocation is always
sufficient, this is just a correctness patch.

Miscellanea:

o Don't use strlen, use *ptr to determine if a string
  should be emitted like all the other tests here
o Delete unnecessary return statements

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-05-17 17:25:35 +02:00
Steven Rostedt (Red Hat)
e71456ae98 netfilter: Remove checks of seq_printf() return values
The return value of seq_printf() is soon to be removed. Remove the
checks from seq_printf() in favor of seq_has_overflowed().

Link: http://lkml.kernel.org/r/20141104142236.GA10239@salvia
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: netfilter-devel@vger.kernel.org
Cc: coreteam@netfilter.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-05 14:11:02 -05:00
Rob Jones
772476df70 net/netfilter/x_tables.c: use __seq_open_private()
Reduce boilerplate code by using __seq_open_private() instead of seq_open()
in xt_match_open() and xt_target_open().

Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-26 18:42:29 +02:00
Pablo Neira Ayuso
7926dbfa4b netfilter: don't use mutex_lock_interruptible()
Eric Dumazet reports that getsockopt() or setsockopt() sometimes
returns -EINTR instead of -ENOPROTOOPT, causing headaches to
application developers.

This patch replaces all the mutex_lock_interruptible() by mutex_lock()
in the netfilter tree, as there is no reason we should sleep for a
long time there.

Reported-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Julian Anastasov <ja@ssi.bg>
2014-08-08 16:47:23 +02:00
Eric Dumazet
f6b50824f7 netfilter: x_tables: xt_free_table_info() cleanup
kvfree() helper can make xt_free_table_info() much cleaner.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-06-25 14:52:16 +02:00
Will Deacon
b416c144f4 netfilter: x_tables: fix ordering of jumpstack allocation and table update
During kernel stability testing on an SMP ARMv7 system, Yalin Wang
reported the following panic from the netfilter code:

  1fe0: 0000001c 5e2d3b10 4007e779 4009e110 60000010 00000032 ff565656 ff545454
  [<c06c48dc>] (ipt_do_table+0x448/0x584) from [<c0655ef0>] (nf_iterate+0x48/0x7c)
  [<c0655ef0>] (nf_iterate+0x48/0x7c) from [<c0655f7c>] (nf_hook_slow+0x58/0x104)
  [<c0655f7c>] (nf_hook_slow+0x58/0x104) from [<c0683bbc>] (ip_local_deliver+0x88/0xa8)
  [<c0683bbc>] (ip_local_deliver+0x88/0xa8) from [<c0683718>] (ip_rcv_finish+0x418/0x43c)
  [<c0683718>] (ip_rcv_finish+0x418/0x43c) from [<c062b1c4>] (__netif_receive_skb+0x4cc/0x598)
  [<c062b1c4>] (__netif_receive_skb+0x4cc/0x598) from [<c062b314>] (process_backlog+0x84/0x158)
  [<c062b314>] (process_backlog+0x84/0x158) from [<c062de84>] (net_rx_action+0x70/0x1dc)
  [<c062de84>] (net_rx_action+0x70/0x1dc) from [<c0088230>] (__do_softirq+0x11c/0x27c)
  [<c0088230>] (__do_softirq+0x11c/0x27c) from [<c008857c>] (do_softirq+0x44/0x50)
  [<c008857c>] (do_softirq+0x44/0x50) from [<c0088614>] (local_bh_enable_ip+0x8c/0xd0)
  [<c0088614>] (local_bh_enable_ip+0x8c/0xd0) from [<c06b0330>] (inet_stream_connect+0x164/0x298)
  [<c06b0330>] (inet_stream_connect+0x164/0x298) from [<c061d68c>] (sys_connect+0x88/0xc8)
  [<c061d68c>] (sys_connect+0x88/0xc8) from [<c000e340>] (ret_fast_syscall+0x0/0x30)
  Code: 2a000021 e59d2028 e59de01c e59f011c (e7824103)
  ---[ end trace da227214a82491bd ]---
  Kernel panic - not syncing: Fatal exception in interrupt

This comes about because CPU1 is executing xt_replace_table in response
to a setsockopt syscall, resulting in:

	ret = xt_jumpstack_alloc(newinfo);
		--> newinfo->jumpstack = kzalloc(size, GFP_KERNEL);

	[...]

	table->private = newinfo;
	newinfo->initial_entries = private->initial_entries;

Meanwhile, CPU0 is handling the network receive path and ends up in
ipt_do_table, resulting in:

	private = table->private;

	[...]

	jumpstack  = (struct ipt_entry **)private->jumpstack[cpu];

On weakly ordered memory architectures, the writes to table->private
and newinfo->jumpstack from CPU1 can be observed out of order by CPU0.
Furthermore, on architectures which don't respect ordering of address
dependencies (i.e. Alpha), the reads from CPU0 can also be re-ordered.

This patch adds an smp_wmb() before the assignment to table->private
(which is essentially publishing newinfo) to ensure that all writes to
newinfo will be observed before plugging it into the table structure.
A dependent-read barrier is also added on the consumer sides, to ensure
the same ordering requirements are also respected there.

Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reported-by: Wang, Yalin <Yalin.Wang@sonymobile.com>
Tested-by: Wang, Yalin <Yalin.Wang@sonymobile.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-22 10:11:29 +02:00
Linus Torvalds
20b4fb4852 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS updates from Al Viro,

Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).

7kloc removed.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
  don't bother with deferred freeing of fdtables
  proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
  proc: Make the PROC_I() and PDE() macros internal to procfs
  proc: Supply a function to remove a proc entry by PDE
  take cgroup_open() and cpuset_open() to fs/proc/base.c
  ppc: Clean up scanlog
  ppc: Clean up rtas_flash driver somewhat
  hostap: proc: Use remove_proc_subtree()
  drm: proc: Use remove_proc_subtree()
  drm: proc: Use minor->index to label things, not PDE->name
  drm: Constify drm_proc_list[]
  zoran: Don't print proc_dir_entry data in debug
  reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
  proc: Supply an accessor for getting the data from a PDE's parent
  airo: Use remove_proc_subtree()
  rtl8192u: Don't need to save device proc dir PDE
  rtl8187se: Use a dir under /proc/net/r8180/
  proc: Add proc_mkdir_data()
  proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
  proc: Move PDE_NET() to fs/proc/proc_net.c
  ...
2013-05-01 17:51:54 -07:00
Patrick McHardy
f229f6ce48 netfilter: add my copyright statements
Add copyright statements to all netfilter files which have had significant
changes done by myself in the past.

Some notes:

- nf_conntrack_ecache.c was incorrectly attributed to Rusty and Netfilter
  Core Team when it got split out of nf_conntrack_core.c. The copyrights
  even state a date which lies six years before it was written. It was
  written in 2005 by Harald and myself.

- net/ipv{4,6}/netfilter.c, net/netfitler/nf_queue.c were missing copyright
  statements. I've added the copyright statement from net/netfilter/core.c,
  where this code originated

- for nf_conntrack_proto_tcp.c I've also added Jozsef, since I didn't want
  it to give the wrong impression

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-04-18 20:27:55 +02:00
Al Viro
d9dda78bad procfs: new helper - PDE_DATA(inode)
The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data.  Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:13:32 -04:00
Gao feng
ece31ffd53 net: proc: change proc_net_remove to remove_proc_entry
proc_net_remove is only used to remove proc entries
that under /proc/net,it's not a general function for
removing proc entries of netns. if we want to remove
some proc entries which under /proc/net/stat/, we still
need to call remove_proc_entry.

this patch use remove_proc_entry to replace proc_net_remove.
we can remove proc_net_remove after this patch.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18 14:53:08 -05:00
Jan Engelhardt
5b76c4948f netfilter: x_tables: print correct hook names for ARP
arptables 0.0.4 (released on 10th Jan 2013) supports calling the
CLASSIFY target, but on adding a rule to the wrong chain, the
diagnostic is as follows:

	# arptables -A INPUT -j CLASSIFY --set-class 0:0
	arptables: Invalid argument
	# dmesg | tail -n1
	x_tables: arp_tables: CLASSIFY target: used from hooks
	PREROUTING, but only usable from INPUT/FORWARD

This is incorrect, since xt_CLASSIFY.c does specify
(1 << NF_ARP_OUT) | (1 << NF_ARP_FORWARD).

This patch corrects the x_tables diagnostic message to print the
proper hook names for the NFPROTO_ARP case.

Affects all kernels down to and including v2.6.31.

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-13 12:54:12 +01:00
Paul Gortmaker
3a9a231d97 net: Fix files explicitly needing to include module.h
With calls to modular infrastructure, these files really
needs the full module.h header.  Call it out so some of the
cleanups of implicit and unrequired includes elsewhere can be
cleaned up.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:28 -04:00
Joe Perches
3dbd443983 net: Convert vmalloc/memset to vzalloc
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-09-15 13:59:25 +02:00
David S. Miller
3c709f8fb4 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-3.6
Conflicts:
	drivers/net/benet/be_main.c
2011-05-11 14:26:58 -04:00
Eric Dumazet
5a6351eecf netfilter: fix ebtables compat support
commit 255d0dc340 (netfilter: x_table: speedup compat operations)
made ebtables not working anymore.

1) xt_compat_calc_jump() is not an exact match lookup
2) compat_table_info() has a typo in xt_compat_init_offsets() call
3) compat_do_replace() misses a xt_compat_init_offsets() call

Reported-by: dann frazier <dannf@dannf.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-05-10 09:48:59 +02:00
Eric Dumazet
7f5c6d4f66 netfilter: get rid of atomic ops in fast path
We currently use a percpu spinlock to 'protect' rule bytes/packets
counters, after various attempts to use RCU instead.

Lately we added a seqlock so that get_counters() can run without
blocking BH or 'writers'. But we really only need the seqcount in it.

Spinlock itself is only locked by the current/owner cpu, so we can
remove it completely.

This cleanups api, using correct 'writer' vs 'reader' semantic.

At replace time, the get_counters() call makes sure all cpus are done
using the old table.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-04-04 17:04:03 +02:00
Patrick McHardy
42046e2e45 netfilter: x_tables: return -ENOENT for non-existant matches/targets
As Stephen correctly points out, we need to return -ENOENT in
xt_find_match()/xt_find_target() after the patch "netfilter: x_tables:
misuse of try_then_request_module" in order to properly indicate
a non-existant module to the caller.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-03-14 19:11:44 +01:00
Stephen Hemminger
adb00ae2ea netfilter: x_tables: misuse of try_then_request_module
Since xt_find_match() returns ERR_PTR(xx) on error not NULL,
the macro try_then_request_module won't work correctly here.
The macro expects its first argument will be zero if condition
fails. But ERR_PTR(-ENOENT) is not zero.

The correct solution is to propagate the error value
back.

Found by inspection, and compile tested only.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-03-09 14:14:26 +01:00
Patrick McHardy
14f0290ba4 Merge branch 'master' of /repos/git/net-next-2.6 2011-01-19 23:51:37 +01:00
Thomas Graf
fbabf31e4d netfilter: create audit records for x_tables replaces
The setsockopt() syscall to replace tables is already recorded
in the audit logs. This patch stores additional information
such as table name and netfilter protocol.

Cc: Patrick McHardy <kaber@trash.net>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Thomas Graf <tgraf@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-01-16 18:12:59 +01:00
Eric Dumazet
255d0dc340 netfilter: x_table: speedup compat operations
One iptables invocation with 135000 rules takes 35 seconds of cpu time
on a recent server, using a 32bit distro and a 64bit kernel.

We eventually trigger NMI/RCU watchdog.

INFO: rcu_sched_state detected stall on CPU 3 (t=6000 jiffies)

COMPAT mode has quadratic behavior and consume 16 bytes of memory per
rule.

Switch the xt_compat algos to use an array instead of list, and use a
binary search to locate an offset in the sorted array.

This halves memory need (8 bytes per rule), and removes quadratic
behavior [ O(N*N) -> O(N*log2(N)) ]

Time of iptables goes from 35 s to 150 ms.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2011-01-13 12:05:12 +01:00
Eric Dumazet
83723d6071 netfilter: x_tables: dont block BH while reading counters
Using "iptables -L" with a lot of rules have a too big BH latency.
Jesper mentioned ~6 ms and worried of frame drops.

Switch to a per_cpu seqlock scheme, so that taking a snapshot of
counters doesnt need to block BH (for this cpu, but also other cpus).

This adds two increments on seqlock sequence per ipt_do_table() call,
its a reasonable cost for allowing "iptables -L" not block BH
processing.

Reported-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McHardy <kaber@trash.net>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2011-01-10 20:11:38 +01:00
Changli Gao
f68c53015c netfilter: unregister nf hooks, matches and targets in the reverse order
Since we register nf hooks, matches and targets in order, we'd better
unregister them in the reverse order.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-04 22:24:12 +02:00
Eric Dumazet
7489aec8ee netfilter: xtables: stackptr should be percpu
commit f3c5c1bfd4 (netfilter: xtables: make ip_tables reentrant)
introduced a performance regression, because stackptr array is shared by
all cpus, adding cache line ping pongs. (16 cpus share a 64 bytes cache
line)

Fix this using alloc_percpu()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-By: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-05-31 16:41:35 +02:00
Xiaotian Feng
c936e8bd1d netfilter: don't xt_jumpstack_alloc twice in xt_register_table
In xt_register_table, xt_jumpstack_alloc is called first, later
xt_replace_table is used. But in xt_replace_table, xt_jumpstack_alloc
will be used again. Then the memory allocated by previous xt_jumpstack_alloc
will be leaked. We can simply remove the previous xt_jumpstack_alloc because
there aren't any users of newinfo between xt_jumpstack_alloc and
xt_replace_table.

Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jan Engelhardt <jengelh@medozas.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Acked-By: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-05-31 16:41:09 +02:00
Jan Engelhardt
d97a9e47ba netfilter: x_tables: move sleeping allocation outside BH-disabled region
The jumpstack allocation needs to be moved out of the critical region.
Corrects this notice:

BUG: sleeping function called from invalid context at mm/slub.c:1705
[  428.295762] in_atomic(): 1, irqs_disabled(): 0, pid: 9111, name: iptables
[  428.295771] Pid: 9111, comm: iptables Not tainted 2.6.34-rc1 #2
[  428.295776] Call Trace:
[  428.295791]  [<c012138e>] __might_sleep+0xe5/0xed
[  428.295801]  [<c019e8ca>] __kmalloc+0x92/0xfc
[  428.295825]  [<f865b3bb>] ? xt_jumpstack_alloc+0x36/0xff [x_tables]

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-04-21 14:45:51 +02:00
Patrick McHardy
6291055465 Merge branch 'master' of /repos/git/net-next-2.6
Conflicts:
	Documentation/feature-removal-schedule.txt
	net/ipv6/netfilter/ip6t_REJECT.c
	net/netfilter/xt_limit.c

Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-04-20 16:02:01 +02:00
Jan Engelhardt
f3c5c1bfd4 netfilter: xtables: make ip_tables reentrant
Currently, the table traverser stores return addresses in the ruleset
itself (struct ip6t_entry->comefrom). This has a well-known drawback:
the jumpstack is overwritten on reentry, making it necessary for
targets to return absolute verdicts. Also, the ruleset (which might
be heavy memory-wise) needs to be replicated for each CPU that can
possibly invoke ip6t_do_table.

This patch decouples the jumpstack from struct ip6t_entry and instead
puts it into xt_table_info. Not being restricted by 'comefrom'
anymore, we can set up a stack as needed. By default, there is room
allocated for two entries into the traverser.

arp_tables is not touched though, because there is just one/two
modules and further patches seek to collapse the table traverser
anyhow.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-04-19 16:05:10 +02:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Jan Engelhardt
d6b00a5345 netfilter: xtables: change targets to return error code
Part of the transition of done by this semantic patch:
// <smpl>
@ rule1 @
struct xt_target ops;
identifier check;
@@
 ops.checkentry = check;

@@
identifier rule1.check;
@@
 check(...) { <...
-return true;
+return 0;
 ...> }

@@
identifier rule1.check;
@@
 check(...) { <...
-return false;
+return -EINVAL;
 ...> }
// </smpl>

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2010-03-25 16:55:49 +01:00
Jan Engelhardt
bd414ee605 netfilter: xtables: change matches to return error code
The following semantic patch does part of the transformation:
// <smpl>
@ rule1 @
struct xt_match ops;
identifier check;
@@
 ops.checkentry = check;

@@
identifier rule1.check;
@@
 check(...) { <...
-return true;
+return 0;
 ...> }

@@
identifier rule1.check;
@@
 check(...) { <...
-return false;
+return -EINVAL;
 ...> }
// </smpl>

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2010-03-25 16:55:24 +01:00
Jan Engelhardt
fd0ec0e621 netfilter: xtables: consolidate code into xt_request_find_match
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2010-03-25 15:02:19 +01:00
Jan Engelhardt
d2a7b6bad2 netfilter: xtables: make use of xt_request_find_target
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2010-03-25 15:02:19 +01:00
Jan Engelhardt
be91fd5e32 netfilter: xtables: replace custom duprintf with pr_debug
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2010-03-18 14:20:07 +01:00
Florian Westphal
3e5e524ffb netfilter: CONFIG_COMPAT: allow delta to exceed 32767
with 32 bit userland and 64 bit kernels, it is unlikely but possible
that insertion of new rules fails even tough there are only about 2000
iptables rules.

This happens because the compat delta is using a short int.
Easily reproducible via "iptables -m limit" ; after about 2050
rules inserting new ones fails with -ELOOP.

Note that compat_delta included 2 bytes of padding on x86_64, so
structure size remains the same.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-02-15 18:17:10 +01:00
Jan Engelhardt
739674fb7f netfilter: xtables: constify args in compat copying functions
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2010-02-15 16:59:28 +01:00
Jan Engelhardt
b402405d71 netfilter: xtables: print details on size mismatch
Print which revision has been used and which size are which
(kernel/user) for easier debugging.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2010-02-15 16:59:28 +01:00
Patrick McHardy
a8c28d0515 Merge branch 'master' of git://dev.medozas.de/linux 2010-02-10 17:56:46 +01:00
Jan Engelhardt
e3eaa9910b netfilter: xtables: generate initial table on-demand
The static initial tables are pretty large, and after the net
namespace has been instantiated, they just hang around for nothing.
This commit removes them and creates tables on-demand at runtime when
needed.

Size shrinks by 7735 bytes (x86_64).

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2010-02-10 17:50:47 +01:00
Jan Engelhardt
2b95efe7f6 netfilter: xtables: use xt_table for hook instantiation
The respective xt_table structures already have most of the metadata
needed for hook setup. Add a 'priority' field to struct xt_table so
that xt_hook_link() can be called with a reduced number of arguments.

So should we be having more tables in the future, it comes at no
static cost (only runtime, as before) - space saved:
6807373->6806555.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2010-02-10 17:13:33 +01:00
Alexey Dobriyan
42107f5009 netfilter: xtables: symmetric COMPAT_XT_ALIGN definition
Rewrite COMPAT_XT_ALIGN in terms of dummy structure hack.
Compat counters logically have nothing to do with it.
Use ALIGN() macro while I'm at it for same types.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-02-10 15:03:27 +01:00