Commit graph

16 commits

Author SHA1 Message Date
Pablo Neira Ayuso 26dfab7216 netfilter: merge nf_iterate() into nf_hook_slow()
nf_iterate() has become rather simple, we can integrate this code into
nf_hook_slow() to reduce the amount of LOC in the core path.

However, we still need nf_iterate() around for nf_queue packet handling,
so move this function there where we only need it. I think it should be
possible to refactor nf_queue code to get rid of it definitely, but
given this is slow path anyway, let's have a look this later.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-03 11:52:59 +01:00
Pablo Neira Ayuso 7034b566a4 netfilter: fix nf_queue handling
nf_queue handling is broken since e3b37f11e6 ("netfilter: replace
list_head with single linked list") for two reasons:

1) If the bypass flag is set on, there are no userspace listeners and
   we still have more hook entries to iterate over, then jump to the
   next hook. Otherwise accept the packet. On nf_reinject() path, the
   okfn() needs to be invoked.

2) We should not re-enter the same hook on packet reinjection. If the
   packet is accepted, we have to skip the current hook from where the
   packet was enqueued, otherwise the packets gets enqueued over and
   over again.

This restores the previous list_for_each_entry_continue() behaviour
happening from nf_iterate() that was dealing with these two cases.
This patch introduces a new nf_queue() wrapper function so this fix
becomes simpler.

Fixes: e3b37f11e6 ("netfilter: replace list_head with single linked list")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-10-20 19:59:59 +02:00
Aaron Conole e3b37f11e6 netfilter: replace list_head with single linked list
The netfilter hook list never uses the prev pointer, and so can be trimmed to
be a simple singly-linked list.

In addition to having a more light weight structure for hook traversal,
struct net becomes 5568 bytes (down from 6400) and struct net_device becomes
2176 bytes (down from 2240).

Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-25 14:38:48 +02:00
Pablo Neira Ayuso 2385eb0c5f netfilter: nf_queue: fix nf_queue_nf_hook_drop()
This function reacquires the rtnl_lock() which is already held by
nf_unregister_hook().

This can be triggered via: modprobe nf_conntrack_ipv4 && rmmod nf_conntrack_ipv4

[  720.628746] INFO: task rmmod:3578 blocked for more than 120 seconds.
[  720.628749]       Not tainted 4.2.0-rc2+ #113
[  720.628752] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  720.628754] rmmod           D ffff8800ca46fd58     0  3578   3571 0x00000080
[...]
[  720.628783] Call Trace:
[  720.628790]  [<ffffffff8152ea0b>] schedule+0x6b/0x90
[  720.628795]  [<ffffffff8152ecb3>] schedule_preempt_disabled+0x13/0x20
[  720.628799]  [<ffffffff8152ff55>] mutex_lock_nested+0x1f5/0x380
[  720.628803]  [<ffffffff81462622>] ? rtnl_lock+0x12/0x20
[  720.628807]  [<ffffffff81462622>] ? rtnl_lock+0x12/0x20
[  720.628812]  [<ffffffff81462622>] rtnl_lock+0x12/0x20
[  720.628817]  [<ffffffff8148ab25>] nf_queue_nf_hook_drop+0x15/0x160
[  720.628825]  [<ffffffff81488d48>] nf_unregister_net_hook+0x168/0x190
[  720.628831]  [<ffffffff81488e24>] nf_unregister_hook+0x64/0x80
[  720.628837]  [<ffffffff81488e60>] nf_unregister_hooks+0x20/0x30
[...]

Moreover, nf_unregister_net_hook() should only destroy the queue for this
netns, not for every netns.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Fixes: 085db2c045 ("netfilter: Per network namespace netfilter hooks.")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-07-23 16:17:58 +02:00
Eric W. Biederman 8405a8fff3 netfilter: nf_qeueue: Drop queue entries on nf_unregister_hook
Add code to nf_unregister_hook to flush the nf_queue when a hook is
unregistered.  This guarantees that the pointer that the nf_queue code
retains into the nf_hook list will remain valid while a packet is
queued.

I tested what would happen if we do not flush queued packets and was
trivially able to obtain the oops below.  All that was required was
to stop the nf_queue listening process, to delete all of the nf_tables,
and to awaken the nf_queue listening process.

> BUG: unable to handle kernel paging request at 0000000100000001
> IP: [<0000000100000001>] 0x100000001
> PGD b9c35067 PUD 0
> Oops: 0010 [#1] SMP
> Modules linked in:
> CPU: 0 PID: 519 Comm: lt-nfqnl_test Not tainted
> task: ffff8800b9c8c050 ti: ffff8800ba9d8000 task.ti: ffff8800ba9d8000
> RIP: 0010:[<0000000100000001>]  [<0000000100000001>] 0x100000001
> RSP: 0018:ffff8800ba9dba40  EFLAGS: 00010a16
> RAX: ffff8800bab48a00 RBX: ffff8800ba9dba90 RCX: ffff8800ba9dba90
> RDX: ffff8800b9c10128 RSI: ffff8800ba940900 RDI: ffff8800bab48a00
> RBP: ffff8800b9c10128 R08: ffffffff82976660 R09: ffff8800ba9dbb28
> R10: dead000000100100 R11: dead000000200200 R12: ffff8800ba940900
> R13: ffffffff8313fd50 R14: ffff8800b9c95200 R15: 0000000000000000
> FS:  00007fb91fc34700(0000) GS:ffff8800bfa00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000100000001 CR3: 00000000babfb000 CR4: 00000000000007f0
> Stack:
>  ffffffff8206ab0f ffffffff82982240 ffff8800bab48a00 ffff8800b9c100a8
>  ffff8800b9c10100 0000000000000001 ffff8800ba940900 ffff8800b9c10128
>  ffffffff8206bd65 ffff8800bfb0d5e0 ffff8800bab48a00 0000000000014dc0
> Call Trace:
>  [<ffffffff8206ab0f>] ? nf_iterate+0x4f/0xa0
>  [<ffffffff8206bd65>] ? nf_reinject+0x125/0x190
>  [<ffffffff8206dee5>] ? nfqnl_recv_verdict+0x255/0x360
>  [<ffffffff81386290>] ? nla_parse+0x80/0xf0
>  [<ffffffff8206c42c>] ? nfnetlink_rcv_msg+0x13c/0x240
>  [<ffffffff811b2fec>] ? __memcg_kmem_get_cache+0x4c/0x150
>  [<ffffffff8206c2f0>] ? nfnl_lock+0x20/0x20
>  [<ffffffff82068159>] ? netlink_rcv_skb+0xa9/0xc0
>  [<ffffffff820677bf>] ? netlink_unicast+0x12f/0x1c0
>  [<ffffffff82067ade>] ? netlink_sendmsg+0x28e/0x650
>  [<ffffffff81fdd814>] ? sock_sendmsg+0x44/0x50
>  [<ffffffff81fde07b>] ? ___sys_sendmsg+0x2ab/0x2c0
>  [<ffffffff810e8f73>] ? __wake_up+0x43/0x70
>  [<ffffffff8141a134>] ? tty_write+0x1c4/0x2a0
>  [<ffffffff81fde9f4>] ? __sys_sendmsg+0x44/0x80
>  [<ffffffff823ff8d7>] ? system_call_fastpath+0x12/0x6a
> Code:  Bad RIP value.
> RIP  [<0000000100000001>] 0x100000001
>  RSP <ffff8800ba9dba40>
> CR2: 0000000100000001
> ---[ end trace 08eb65d42362793f ]---

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-23 06:23:23 -07:00
David S. Miller cfdfab3146 netfilter: Create and use nf_hook_state.
Instead of passing a large number of arguments down into the nf_hook()
entry points, create a structure which carries this state down through
the hook processing layers.

This makes is so that if we want to change the types or signatures of
any of these pieces of state, there are less places that need to be
changed.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-04 12:17:40 -04:00
Joe Perches c1b1203d65 net: misc: Remove extern from function prototypes
There are a mix of function prototypes with and without extern
in the kernel sources.  Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler.  Its use is as unnecessary as
using auto to declare automatic/local variables in a block.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19 19:12:11 -04:00
Michael Wang 1c15b67709 netfilter: pass 'nf_hook_ops' instead of 'list_head' to nf_queue()
Since 'list_for_each_continue_rcu' has already been replaced by
'list_for_each_entry_continue_rcu', pass 'list_head' to nf_queue() as a
parameter can not benefit us any more.

This patch will replace 'list_head' with 'nf_hook_ops' as the parameter of
nf_queue() and __nf_queue() to save code.

Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-09-03 13:52:54 +02:00
Michael Wang 2a6decfd8a netfilter: pass 'nf_hook_ops' instead of 'list_head' to nf_iterate()
Since 'list_for_each_continue_rcu' has already been replaced by
'list_for_each_entry_continue_rcu', pass 'list_head' to nf_iterate() as a
parameter can not benefit us any more.

This patch will replace 'list_head' with 'nf_hook_ops' as the parameter of
nf_iterate() to save code.

Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-09-03 13:52:44 +02:00
Stephen Hemminger 654d0fbdc8 netfilter: cleanup printk messages
Make sure all printk messages have a severity level.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-05-13 15:02:08 +02:00
Jan Engelhardt 76108cea06 netfilter: Use unsigned types for hooknum and pf vars
and (try to) consistently use u_int8_t for the L3 family.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2008-10-08 11:35:00 +02:00
Herbert Xu 3db05fea51 [NETFILTER]: Replace sk_buff ** with sk_buff *
With all the users of the double pointers removed, this patch mops up by
finally replacing all occurances of sk_buff ** in the netfilter API by
sk_buff *.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-15 12:26:29 -07:00
YOSHIFUJI Hideaki 601e68e100 [NETFILTER]: Fix whitespace errors
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-12 11:15:49 -08:00
Patrick McHardy 394f545db6 [NETFILTER]: nf_queue: handle GSO packets
Handle GSO packets in nf_queue by segmenting them before queueing to
avoid breaking GSO in case they get mangled.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22 14:53:55 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Harald Welte f6ebe77f95 [NETFILTER]: split net/core/netfilter.c into net/netfilter/*.c
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: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:51:11 -07:00