Like many other places, we have to check that the array index is
within allowed limits, or otherwise, a kernel oops and other nastiness
can ensue when we access memory beyond the end of the array.

[ 5954.115381] BUG: unable to handle kernel paging request at 0000004000000000
[ 5954.120014] IP:  __find_logger+0x6f/0xa0
[ 5954.123979]  nf_log_bind_pf+0x2b/0x70
[ 5954.123979]  nfulnl_recv_config+0xc0/0x4a0 [nfnetlink_log]
[ 5954.123979]  nfnetlink_rcv_msg+0x12c/0x1b0 [nfnetlink]
...

The problem goes back to v2.6.30-rc1~1372~1342~31 where nf_log_bind
was decoupled from nf_log_register.

Reported-by: Miguel Di Ciurcio Filho <miguel.filho@gmail.com>,
  via irc.freenode.net/#netfilter
Signed-off-by: NJan Engelhardt <jengelh@medozas.de>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NPatrick McHardy <kaber@trash.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Restore the rcu_dereference() calls in conntrack/expectation notifier
and logger registration/unregistration, but use the _protected variant,
which will be required by the upcoming __rcu annotations.

Based on patch by Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

The CONFIG_PROVE_RCU option discovered a few invalid uses of
rcu_dereference() in netfilter. In all these cases, the code code
intends to check whether a pointer is already assigned when
performing registration or whether the assigned pointer matches
when performing unregistration. The entire registration/
unregistration is protected by a mutex, so we don't need the
rcu_dereference() calls.
Reported-by: NValdis Kletnieks <Valdis.Kletnieks@vt.edu>
Tested-by: NValdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

[  171.925285] BUG: sleeping function called from invalid context at kernel/mutex.c:280
[  171.925296] in_atomic(): 1, irqs_disabled(): 0, pid: 671, name: grep
[  171.925306] 2 locks held by grep/671:
[  171.925312]  #0:  (&p->lock){+.+.+.}, at: [<c10b8acd>] seq_read+0x25/0x36c
[  171.925340]  #1:  (rcu_read_lock){.+.+..}, at: [<c1391dac>] seq_start+0x0/0x44
[  171.925372] Pid: 671, comm: grep Not tainted 2.6.31.6-4-netbook #3
[  171.925380] Call Trace:
[  171.925398]  [<c105104e>] ? __debug_show_held_locks+0x1e/0x20
[  171.925414]  [<c10264ac>] __might_sleep+0xfb/0x102
[  171.925430]  [<c1461521>] mutex_lock_nested+0x1c/0x2ad
[  171.925444]  [<c1391c9e>] seq_show+0x74/0x127
[  171.925456]  [<c10b8c5c>] seq_read+0x1b4/0x36c
[  171.925469]  [<c10b8aa8>] ? seq_read+0x0/0x36c
[  171.925483]  [<c10d5c8e>] proc_reg_read+0x60/0x74
[  171.925496]  [<c10d5c2e>] ? proc_reg_read+0x0/0x74
[  171.925510]  [<c10a4468>] vfs_read+0x87/0x110
[  171.925523]  [<c10a458a>] sys_read+0x3b/0x60
[  171.925538]  [<c1002a49>] syscall_call+0x7/0xb

Fix it by replacing RCU with nf_log_mutex.
Reported-by: N"Yin, Kangkai" <kangkai.yin@intel.com>
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

[  171.925285] BUG: sleeping function called from invalid context at kernel/mutex.c:280
[  171.925296] in_atomic(): 1, irqs_disabled(): 0, pid: 671, name: grep
[  171.925306] 2 locks held by grep/671:
[  171.925312]  #0:  (&p->lock){+.+.+.}, at: [<c10b8acd>] seq_read+0x25/0x36c
[  171.925340]  #1:  (rcu_read_lock){.+.+..}, at: [<c1391dac>] seq_start+0x0/0x44
[  171.925372] Pid: 671, comm: grep Not tainted 2.6.31.6-4-netbook #3
[  171.925380] Call Trace:
[  171.925398]  [<c105104e>] ? __debug_show_held_locks+0x1e/0x20
[  171.925414]  [<c10264ac>] __might_sleep+0xfb/0x102
[  171.925430]  [<c1461521>] mutex_lock_nested+0x1c/0x2ad
[  171.925444]  [<c1391c9e>] seq_show+0x74/0x127
[  171.925456]  [<c10b8c5c>] seq_read+0x1b4/0x36c
[  171.925469]  [<c10b8aa8>] ? seq_read+0x0/0x36c
[  171.925483]  [<c10d5c8e>] proc_reg_read+0x60/0x74
[  171.925496]  [<c10d5c2e>] ? proc_reg_read+0x0/0x74
[  171.925510]  [<c10a4468>] vfs_read+0x87/0x110
[  171.925523]  [<c10a458a>] sys_read+0x3b/0x60
[  171.925538]  [<c1002a49>] syscall_call+0x7/0xb

Fix it by replacing RCU with nf_log_mutex.
Reported-by: N"Yin, Kangkai" <kangkai.yin@intel.com>
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

Now that sys_sysctl is a compatiblity wrapper around /proc/sys
all sysctl strategy routines, and all ctl_name and strategy
entries in the sysctl tables are unused, and can be
revmoed.

In addition neigh_sysctl_register has been modified to no longer
take a strategy argument and it's callers have been modified not
to pass one.

Cc: "David Miller" <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: netdev@vger.kernel.org
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

It's unused.

It isn't needed -- read or write flag is already passed and sysctl
shouldn't care about the rest.

It _was_ used in two places at arch/frv for some reason.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NPatrick McHardy <kaber@trash.net>

Fix regression introduced by 17625274 "netfilter: sysctl support of
logger choice":

BUG: sleeping function called from invalid context at /mnt/s390test/linux-2.6-tip/arch/s390/include/asm/uaccess.h:234
in_atomic(): 1, irqs_disabled(): 0, pid: 3245, name: sysctl
CPU: 1 Not tainted 2.6.30-rc8-tipjun10-02053-g39ae214 #1
Process sysctl (pid: 3245, task: 000000007f675da0, ksp: 000000007eb17cf0)
0000000000000000 000000007eb17be8 0000000000000002 0000000000000000
       000000007eb17c88 000000007eb17c00 000000007eb17c00 0000000000048156
       00000000003e2de8 000000007f676118 000000007eb17f10 0000000000000000
       0000000000000000 000000007eb17be8 000000000000000d 000000007eb17c58
       00000000003e2050 000000000001635c 000000007eb17be8 000000007eb17c30
Call Trace:
(<00000000000162e6> show_trace+0x13a/0x148)
 <00000000000349ea> __might_sleep+0x13a/0x164
 <0000000000050300> proc_dostring+0x134/0x22c
 <0000000000312b70> nf_log_proc_dostring+0xfc/0x188
 <0000000000136f5e> proc_sys_call_handler+0xf6/0x118
 <0000000000136fda> proc_sys_read+0x26/0x34
 <00000000000d6e9c> vfs_read+0xac/0x158
 <00000000000d703e> SyS_read+0x56/0x88
 <0000000000027f42> sysc_noemu+0x10/0x16

Use the nf_log_mutex instead of RCU to fix this.
Reported-and-tested-by: NMaran Pakkirisamy <maranpsamy@in.ibm.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

commit ca735b3a
'netfilter: use a linked list of loggers'
introduced an array of list_head in "struct nf_logger", but
forgot to initialize it in nf_log_register(). This resulted
in oops when calling nf_log_unregister() at module unload time.
Reported-and-tested-by: NMariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Acked-by: NEric Leblond <eric@inl.fr>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

This patchs adds support of modification of the used logger via sysctl.
It can be used to change the logger to module that can not use the bind
operation (ipt_LOG and ipt_ULOG). For this purpose, it creates a
directory /proc/sys/net/netfilter/nf_log which contains a file
per-protocol. The content of the file is the name current logger (NONE if
not set) and a logger can be setup by simply echoing its name to the file.
By echoing "NONE" to a /proc/sys/net/netfilter/nf_log/PROTO file, the
logger corresponding to this PROTO is set to NULL.
Signed-off-by: NEric Leblond <eric@inl.fr>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

This patch modifies the proc output to add display of registered
loggers. The content of /proc/net/netfilter/nf_log is modified. Instead
of displaying a protocol per line with format:
	proto:logger
it now displays:
	proto:logger (comma_separated_list_of_loggers)
NONE is used as keyword if no logger is used.
Signed-off-by: NEric Leblond <eric@inl.fr>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

This patch modifies nf_log to use a linked list of loggers for each
protocol. This list of loggers is read and write protected with a
mutex.

This patch separates registration and binding. To be used as
logging module, a module has to register calling nf_log_register()
and to bind to a protocol it has to call nf_log_bind_pf().
This patch also converts the logging modules to the new API. For nfnetlink_log,
it simply switchs call to register functions to call to bind function and
adds a call to nf_log_register() during init. For other modules, it just
remove a const flag from the logger structure and replace it with a
__read_mostly.
Signed-off-by: NEric Leblond <eric@inl.fr>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

The netfilter subsystem only supports a handful of protocols (much
less than PF_*) and even non-PF protocols like ARP and
pseudo-protocols like PF_BRIDGE. By creating NFPROTO_*, we can earn a
few memory savings on arrays that previously were always PF_MAX-sized
and keep the pseudo-protocols to ourselves.
Signed-off-by: NJan Engelhardt <jengelh@medozas.de>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

and (try to) consistently use u_int8_t for the L3 family.
Signed-off-by: NJan Engelhardt <jengelh@medozas.de>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

The message "nf_log_packet: can't log since no backend logging module loaded
in! Please either load one, or disable logging explicitly" was displayed for
each logged packet when no userspace application is listening to nflog events.
The message seems to warn for a problem with a kernel module missing but as
said before this is not the case. I thus propose to suppress the message (I
don't see any reason to flood the log because a user application has crashed.)
Signed-off-by: NEric Leblond <eric@inl.fr>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This elliminates infamous race during module loading when one could lookup
proc entry without proc_fops assigned.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

  CHECK   net/netfilter/nf_conntrack_expect.c
net/netfilter/nf_conntrack_expect.c:429:13: warning: context imbalance in 'exp_seq_start' - wrong count at exit
net/netfilter/nf_conntrack_expect.c:441:13: warning: context imbalance in 'exp_seq_stop' - unexpected unlock
  CHECK   net/netfilter/nf_log.c
net/netfilter/nf_log.c:105:13: warning: context imbalance in 'seq_start' - wrong count at exit
net/netfilter/nf_log.c:125:13: warning: context imbalance in 'seq_stop' - unexpected unlock
  CHECK   net/netfilter/nfnetlink_queue.c
net/netfilter/nfnetlink_queue.c:363:7: warning: symbol 'size' shadows an earlier one
net/netfilter/nfnetlink_queue.c:217:9: originally declared here
net/netfilter/nfnetlink_queue.c:847:13: warning: context imbalance in 'seq_start' - wrong count at exit
net/netfilter/nfnetlink_queue.c:859:13: warning: context imbalance in 'seq_stop' - unexpected unlock
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Whatever that comment tries to say, I don't get it and it looks like
a leftover from the time when RCU wasn't used properly.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Make all initialized struct seq_operations in net/ const
Signed-off-by: NPhilippe De Muyter <phdm@macqel.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

- rename nf_logging to nf_loggers since its an array of registered loggers

- rename nf_log_unregister_logger() to nf_log_unregister() to make it
  symetrical to nf_log_register() and convert all users
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The spinlock is only used in process context (register/unregister),
switch to a mutex.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the only user of nf_log_unregister_pf (nfnetlink_log) doesn't
check the return value, change it to void and bail out silently when
a non-existant address family is supplied.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Also replace synchronize_net() calls by synchronize_rcu() since the
RCU protected data is also used for sysfs.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Signed-off-by: NHarald Welte <laforge@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Check whether pf is too large in order to prevent array overflow.
Signed-off-by: NHarald Welte <laforge@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds EEXIST to distinguish between the following return values:
0: 	nobody was registered, registration successful
EEXIST:	the exact same handler was already registered, no registration
	required
EBUSY:	somebody else is registered, registration unsuccessful.
Signed-off-by: NHarald Welte <laforge@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a /proc/net/netfilter/nf_queue file, similar to the
recently-added /proc/net/netfilter/nf_log.  It indicates which queue
handler is registered to which protocol family.  This is useful since
there are now multiple queue handlers in the treee (ip[6]_queue,
nfnetlink_queue).
Signed-off-by: NHarald Welte <laforge@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch doesn't introduce any code changes, but merely splits the
core netfilter code into four separate files.  It also moves it from
it's old location in net/core/ to the recently-created net/netfilter/
directory.
Signed-off-by: NHarald Welte <laforge@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>