[ Upstream commit 3e673b23b5 ]
Shaochun Chen points out we leak dumper filter state allocations
stored in dump_control->data in case there is an error before netlink sets
cb_running (after which ->done will be called at some point).
In order to fix this, add .start functions and move allocations there.
Same pattern as used in commit 90fd131afc
("netfilter: nf_tables: move dumper state allocation into ->start").
Reported-by: shaochun chen <cscnull@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Doesn't change generated code, but will make it easier to eventually
make the actual trackers themselvers const.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
avoids a pointer and allows struct to be const later on.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When a nf_conntrack_l3/4proto parameter is not on the left hand side
of an assignment, its address is not taken, and it is not passed to a
function that may modify its fields, then it can be declared as const.
This change is useful from a documentation point of view, and can
possibly facilitate making some nf_conntrack_l3/4proto structures const
subsequently.
Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We have several spots that open-code a expect walk, add a helper
that is similar to nf_ct_iterate_destroy/nf_ct_iterate_cleanup.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch removes duplicate rcu_read_lock().
1. IPVS part:
According to Julian Anastasov's mention, contexts of ipvs are described
at: http://marc.info/?l=netfilter-devel&m=149562884514072&w=2, in summary:
- packet RX/TX: does not need locks because packets come from hooks.
- sync msg RX: backup server uses RCU locks while registering new
connections.
- ip_vs_ctl.c: configuration get/set, RCU locks needed.
- xt_ipvs.c: It is a netfilter match, running from hook context.
As result, rcu_read_lock and rcu_read_unlock can be removed from:
- ip_vs_core.c: all
- ip_vs_ctl.c:
- only from ip_vs_has_real_service
- ip_vs_ftp.c: all
- ip_vs_proto_sctp.c: all
- ip_vs_proto_tcp.c: all
- ip_vs_proto_udp.c: all
- ip_vs_xmit.c: all (contains only packet processing)
2. Netfilter part:
There are three types of functions that are guaranteed the rcu_read_lock().
First, as result, functions are only called by nf_hook():
- nf_conntrack_broadcast_help(), pptp_expectfn(), set_expected_rtp_rtcp().
- tcpmss_reverse_mtu(), tproxy_laddr4(), tproxy_laddr6().
- match_lookup_rt6(), check_hlist(), hashlimit_mt_common().
- xt_osf_match_packet().
Second, functions that caller already held the rcu_read_lock().
- destroy_conntrack(), ctnetlink_conntrack_event().
- ctnl_timeout_find_get(), nfqnl_nf_hook_drop().
Third, functions that are mixed with type1 and type2.
These functions are called by nf_hook() also these are called by
ordinary functions that already held the rcu_read_lock():
- __ctnetlink_glue_build(), ctnetlink_expect_event().
- ctnetlink_proto_size().
Applied files are below:
- nf_conntrack_broadcast.c, nf_conntrack_core.c, nf_conntrack_netlink.c.
- nf_conntrack_pptp.c, nf_conntrack_sip.c, nfnetlink_cttimeout.c.
- nfnetlink_queue.c, xt_TCPMSS.c, xt_TPROXY.c, xt_addrtype.c.
- xt_connlimit.c, xt_hashlimit.c, xt_osf.c
Detailed calltrace can be found at:
http://marc.info/?l=netfilter-devel&m=149667610710350&w=2
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for your net-next
tree. This batch contains connection tracking updates for the cleanup
iteration path, patches from Florian Westphal:
X) Skip unconfirmed conntracks in nf_ct_iterate_cleanup_net(), just set
dying bit to let the CPU release them.
X) Add nf_ct_iterate_destroy() to be used on module removal, to kill
conntrack from all namespace.
X) Restart iteration on hashtable resizing, since both may occur at
the same time.
X) Use the new nf_ct_iterate_destroy() to remove conntrack with NAT
mapping on module removal.
X) Use nf_ct_iterate_destroy() to remove conntrack entries helper
module removal, from Liping Zhang.
X) Use nf_ct_iterate_cleanup_net() to remove the timeout extension
if user requests this, also from Liping.
X) Add net_ns_barrier() and use it from FTP helper, so make sure
no concurrent namespace removal happens at the same time while
the helper module is being removed.
X) Use NFPROTO_MAX in layer 3 conntrack protocol array, to reduce
module size. Same thing in nf_tables.
Updates for the nf_tables infrastructure:
X) Prepare usage of the extended ACK reporting infrastructure for
nf_tables.
X) Remove unnecessary forward declaration in nf_tables hash set.
X) Skip set size estimation if number of element is not specified.
X) Changes to accomodate a (faster) unresizable hash set implementation,
for anonymous sets and dynamic size fixed sets with no timeouts.
X) Faster lookup function for unresizable hash table for 2 and 4
bytes key.
And, finally, a bunch of asorted small updates and cleanups:
X) Do not hold reference to netdev from ipt_CLUSTER, instead subscribe
to device events and look up for index from the packet path, this
is fixing an issue that is present since the very beginning, patch
from Xin Long.
X) Use nf_register_net_hook() in ipt_CLUSTER, from Florian Westphal.
X) Use ebt_invalid_target() whenever possible in the ebtables tree,
from Gao Feng.
X) Calm down compilation warning in nf_dup infrastructure, patch from
stephen hemminger.
X) Statify functions in nftables rt expression, also from stephen.
X) Update Makefile to use canonical method to specify nf_tables-objs.
From Jike Song.
X) Use nf_conntrack_helpers_register() in amanda and H323.
X) Space cleanup for ctnetlink, from linzhang.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass down struct netlink_ext_ack as parameter to all of our nfnetlink
subsystem callbacks, so we can work on follow up patches to provide
finer grain error reporting using the new infrastructure that
2d4bc93368 ("netlink: extended ACK reporting") provides.
No functional change, just pass down this new object to callbacks.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
There are several places where we needlesly call nf_ct_iterate_cleanup,
we should instead iterate the full table at module unload time.
This is a leftover from back when the conntrack table got duplicated
per net namespace.
So rename nf_ct_iterate_cleanup to nf_ct_iterate_cleanup_net.
A later patch will then add a non-net variant.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If nf_conntrack_htable_size was adjusted by the user during the ct
dump operation, we may invoke nf_ct_put twice for the same ct, i.e.
the "last" ct. This will cause the ct will be freed but still linked
in hash buckets.
It's very easy to reproduce the problem by the following commands:
# while : ; do
echo $RANDOM > /proc/sys/net/netfilter/nf_conntrack_buckets
done
# while : ; do
conntrack -L
done
# iperf -s 127.0.0.1 &
# iperf -c 127.0.0.1 -P 60 -t 36000
After a while, the system will hang like this:
NMI watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [bash:20184]
NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [iperf:20382]
...
So at last if we find cb->args[1] is equal to "last", this means hash
resize happened, then we can set cb->args[1] to 0 to fix the above
issue.
Fixes: d205dc4079 ("[NETFILTER]: ctnetlink: fix deadlock in table dumping")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch fixes the creation of connection tracking entry from
netlink when synproxy is used. It was missing the addition of
the synproxy extension.
This was causing kernel crashes when a conntrack entry created by
conntrackd was used after the switch of traffic from active node
to the passive node.
Signed-off-by: Eric Leblond <eric@regit.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Not all parameters passed to ctnetlink_parse_tuple() and
ctnetlink_exp_dump_tuple() match the enum type in the signatures of these
functions. Since this is intended change the argument type of to be an
unsigned integer value.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS/OVS fixes for net
The following patchset contains a rather large batch of Netfilter, IPVS
and OVS fixes for your net tree. This includes fixes for ctnetlink, the
userspace conntrack helper infrastructure, conntrack OVS support,
ebtables DNAT target, several leaks in error path among other. More
specifically, they are:
1) Fix reference count leak in the CT target error path, from Gao Feng.
2) Remove conntrack entry clashing with a matching expectation, patch
from Jarno Rajahalme.
3) Fix bogus EEXIST when registering two different userspace helpers,
from Liping Zhang.
4) Don't leak dummy elements in the new bitmap set type in nf_tables,
from Liping Zhang.
5) Get rid of module autoload from conntrack update path in ctnetlink,
we don't need autoload at this late stage and it is happening with
rcu read lock held which is not good. From Liping Zhang.
6) Fix deadlock due to double-acquire of the expect_lock from conntrack
update path, this fixes a bug that was introduced when the central
spinlock got removed. Again from Liping Zhang.
7) Safe ct->status update from ctnetlink path, from Liping. The expect_lock
protection that was selected when the central spinlock was removed was
not really protecting anything at all.
8) Protect sequence adjustment under ct->lock.
9) Missing socket match with IPv6, from Peter Tirsek.
10) Adjust skb->pkt_type of DNAT'ed frames from ebtables, from
Linus Luessing.
11) Don't give up on evaluating the expression on new entries added via
dynset expression in nf_tables, from Liping Zhang.
12) Use skb_checksum() when mangling icmpv6 in IPv6 NAT as this deals
with non-linear skbuffs.
13) Don't allow IPv6 service in IPVS if no IPv6 support is available,
from Paolo Abeni.
14) Missing mutex release in error path of xt_find_table_lock(), from
Dan Carpenter.
15) Update maintainers files, Netfilter section. Add Florian to the
file, refer to nftables.org and change project status from Supported
to Maintained.
16) Bail out on mismatching extensions in element updates in nf_tables.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter updates for your net-next
tree. A large bunch of code cleanups, simplify the conntrack extension
codebase, get rid of the fake conntrack object, speed up netns by
selective synchronize_net() calls. More specifically, they are:
1) Check for ct->status bit instead of using nfct_nat() from IPVS and
Netfilter codebase, patch from Florian Westphal.
2) Use kcalloc() wherever possible in the IPVS code, from Varsha Rao.
3) Simplify FTP IPVS helper module registration path, from Arushi Singhal.
4) Introduce nft_is_base_chain() helper function.
5) Enforce expectation limit from userspace conntrack helper,
from Gao Feng.
6) Add nf_ct_remove_expect() helper function, from Gao Feng.
7) NAT mangle helper function return boolean, from Gao Feng.
8) ctnetlink_alloc_expect() should only work for conntrack with
helpers, from Gao Feng.
9) Add nfnl_msg_type() helper function to nfnetlink to build the
netlink message type.
10) Get rid of unnecessary cast on void, from simran singhal.
11) Use seq_puts()/seq_putc() instead of seq_printf() where possible,
also from simran singhal.
12) Use list_prev_entry() from nf_tables, from simran signhal.
13) Remove unnecessary & on pointer function in the Netfilter and IPVS
code.
14) Remove obsolete comment on set of rules per CPU in ip6_tables,
no longer true. From Arushi Singhal.
15) Remove duplicated nf_conntrack_l4proto_udplite4, from Gao Feng.
16) Remove unnecessary nested rcu_read_lock() in
__nf_nat_decode_session(). Code running from hooks are already
guaranteed to run under RCU read side.
17) Remove deadcode in nf_tables_getobj(), from Aaron Conole.
18) Remove double assignment in nf_ct_l4proto_pernet_unregister_one(),
also from Aaron.
19) Get rid of unsed __ip_set_get_netlink(), from Aaron Conole.
20) Don't propagate NF_DROP error to userspace via ctnetlink in
__nf_nat_alloc_null_binding() function, from Gao Feng.
21) Revisit nf_ct_deliver_cached_events() to remove unnecessary checks,
from Gao Feng.
22) Kill the fake untracked conntrack objects, use ctinfo instead to
annotate a conntrack object is untracked, from Florian Westphal.
23) Remove nf_ct_is_untracked(), now obsolete since we have no
conntrack template anymore, from Florian.
24) Add event mask support to nft_ct, also from Florian.
25) Move nf_conn_help structure to
include/net/netfilter/nf_conntrack_helper.h.
26) Add a fixed 32 bytes scratchpad area for conntrack helpers.
Thus, we don't deal with variable conntrack extensions anymore.
Make sure userspace conntrack helper doesn't go over that size.
Remove variable size ct extension infrastructure now this code
got no more clients. From Florian Westphal.
27) Restore offset and length of nf_ct_ext structure to 8 bytes now
that wraparound is not possible any longer, also from Florian.
28) Allow to get rid of unassured flows under stress in conntrack,
this applies to DCCP, SCTP and TCP protocols, from Florian.
29) Shrink size of nf_conntrack_ecache structure, from Florian.
30) Use TCP_MAX_WSCALE instead of hardcoded 14 in TCP tracker,
from Gao Feng.
31) Register SYNPROXY hooks on demand, from Florian Westphal.
32) Use pernet hook whenever possible, instead of global hook
registration, from Florian Westphal.
33) Pass hook structure to ebt_register_table() to consolidate some
infrastructure code, from Florian Westphal.
34) Use consume_skb() and return NF_STOLEN, instead of NF_DROP in the
SYNPROXY code, to make sure device stats are not fooled, patch
from Gao Feng.
35) Remove NF_CT_EXT_F_PREALLOC this kills quite some code that we
don't need anymore if we just select a fixed size instead of
expensive runtime time calculation of this. From Florian.
36) Constify nf_ct_extend_register() and nf_ct_extend_unregister(),
from Florian.
37) Simplify nf_ct_ext_add(), this kills nf_ct_ext_create(), from
Florian.
38) Attach NAT extension on-demand from masquerade and pptp helper
path, from Florian.
39) Get rid of useless ip_vs_set_state_timeout(), from Aaron Conole.
40) Speed up netns by selective calls of synchronize_net(), from
Florian Westphal.
41) Silence stack size warning gcc in 32-bit arch in snmp helper,
from Florian.
42) Inconditionally call nf_ct_ext_destroy(), even if we have no
extensions, to deal with the NF_NAT_MANIP_SRC case. Patch from
Liping Zhang.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
We should acquire the ct->lock before accessing or modifying the
nf_ct_seqadj, as another CPU may modify the nf_ct_seqadj at the same
time during its packet proccessing.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
After converting to use rcu for conntrack hash, one CPU may update
the ct->status via ctnetlink, while another CPU may process the
packets and update the ct->status.
So the non-atomic operation "ct->status |= status;" via ctnetlink
becomes unsafe, and this may clear the IPS_DYING_BIT bit set by
another CPU unexpectedly. For example:
CPU0 CPU1
ctnetlink_change_status __nf_conntrack_find_get
old = ct->status nf_ct_gc_expired
- nf_ct_kill
- test_and_set_bit(IPS_DYING_BIT
new = old | status; -
ct->status = new; <-- oops, _DYING_ is cleared!
Now using a series of atomic bit operation to solve the above issue.
Also note, user shouldn't set IPS_TEMPLATE, IPS_SEQ_ADJUST directly,
so make these two bits be unchangable too.
If we set the IPS_TEMPLATE_BIT, ct will be freed by nf_ct_tmpl_free,
but actually it is alloced by nf_conntrack_alloc.
If we set the IPS_SEQ_ADJUST_BIT, this may cause the NULL pointer
deference, as the nfct_seqadj(ct) maybe NULL.
Last, add some comments to describe the logic change due to the
commit a963d710f3 ("netfilter: ctnetlink: Fix regression in CTA_STATUS
processing"), which makes me feel a little confusing.
Fixes: 76507f69c4 ("[NETFILTER]: nf_conntrack: use RCU for conntrack hash")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently, ctnetlink_change_conntrack is always protected by _expect_lock,
but this will cause a deadlock when deleting the helper from a conntrack,
as the _expect_lock will be acquired again by nf_ct_remove_expectations:
CPU0
----
lock(nf_conntrack_expect_lock);
lock(nf_conntrack_expect_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by lt-conntrack_gr/12853:
#0: (&table[i].mutex){+.+.+.}, at: [<ffffffffa05e2009>]
nfnetlink_rcv_msg+0x399/0x6a9 [nfnetlink]
#1: (nf_conntrack_expect_lock){+.....}, at: [<ffffffffa05f2c1f>]
ctnetlink_new_conntrack+0x17f/0x408 [nf_conntrack_netlink]
Call Trace:
dump_stack+0x85/0xc2
__lock_acquire+0x1608/0x1680
? ctnetlink_parse_tuple_proto+0x10f/0x1c0 [nf_conntrack_netlink]
lock_acquire+0x100/0x1f0
? nf_ct_remove_expectations+0x32/0x90 [nf_conntrack]
_raw_spin_lock_bh+0x3f/0x50
? nf_ct_remove_expectations+0x32/0x90 [nf_conntrack]
nf_ct_remove_expectations+0x32/0x90 [nf_conntrack]
ctnetlink_change_helper+0xc6/0x190 [nf_conntrack_netlink]
ctnetlink_new_conntrack+0x1b2/0x408 [nf_conntrack_netlink]
nfnetlink_rcv_msg+0x60a/0x6a9 [nfnetlink]
? nfnetlink_rcv_msg+0x1b9/0x6a9 [nfnetlink]
? nfnetlink_bind+0x1a0/0x1a0 [nfnetlink]
netlink_rcv_skb+0xa4/0xc0
nfnetlink_rcv+0x87/0x770 [nfnetlink]
Since the operations are unrelated to nf_ct_expect, so we can drop the
_expect_lock. Also note, after removing the _expect_lock protection,
another CPU may invoke nf_conntrack_helper_unregister, so we should
use rcu_read_lock to protect __nf_conntrack_helper_find invoked by
ctnetlink_change_helper.
Fixes: ca7433df3a ("netfilter: conntrack: seperate expect locking from nf_conntrack_lock")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
First, when creating a new ct, we will invoke request_module to try to
load the related inkernel cthelper. So there's no need to call the
request_module again when updating the ct helpinfo.
Second, ctnetlink_change_helper may be called with rcu_read_lock held,
i.e. rcu_read_lock -> nfqnl_recv_verdict -> nfqnl_ct_parse ->
ctnetlink_glue_parse -> ctnetlink_glue_parse_ct ->
ctnetlink_change_helper. But the request_module invocation may sleep,
so we can't call it with the rcu_read_lock held.
Remove it now.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Conflicts were simply overlapping changes. In the net/ipv4/route.c
case the code had simply moved around a little bit and the same fix
was made in both 'net' and 'net-next'.
In the net/sched/sch_generic.c case a fix in 'net' happened at
the same time that a new argument was added to qdisc_hash_add().
Signed-off-by: David S. Miller <davem@davemloft.net>
This function is now obsolete and always returns false.
This change has no effect on generated code.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We should use proper RCU list APIs to manipulate help->expectations,
as we can dump the conntrack's expectations via nfnetlink, i.e. in
ctnetlink_exp_ct_dump_table(), where only rcu_read_lock is acquired.
So for list traversal, use hlist_for_each_entry_rcu; for list add/del,
use hlist_add_head_rcu and hlist_del_rcu.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
For IPCTNL_MSG_EXP_GET, if the CTA_EXPECT_MASTER attr is specified, then
the NLM_F_DUMP request will dump the expectations related to this
connection tracking.
But we forget to check whether the conntrack has nf_conn_help or not,
so if nfct_help(ct) is NULL, oops will happen:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: ctnetlink_exp_ct_dump_table+0xf9/0x1e0 [nf_conntrack_netlink]
Call Trace:
? ctnetlink_exp_ct_dump_table+0x75/0x1e0 [nf_conntrack_netlink]
netlink_dump+0x124/0x2a0
__netlink_dump_start+0x161/0x190
ctnetlink_dump_exp_ct+0x16c/0x1bc [nf_conntrack_netlink]
? ctnetlink_exp_fill_info.constprop.33+0xf0/0xf0 [nf_conntrack_netlink]
? ctnetlink_glue_seqadj+0x20/0x20 [nf_conntrack_netlink]
ctnetlink_get_expect+0x32e/0x370 [nf_conntrack_netlink]
? debug_lockdep_rcu_enabled+0x1d/0x20
nfnetlink_rcv_msg+0x60a/0x6a9 [nfnetlink]
? nfnetlink_rcv_msg+0x1b9/0x6a9 [nfnetlink]
[...]
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
One CPU is doing ctnetlink_change_helper(), while another CPU is doing
unhelp() at the same time. So even if help->helper is not NULL at first,
the later statement strcmp(help->helper->name, ...) may still access
the NULL pointer.
So we must use rcu_read_lock and rcu_dereference to avoid such _bad_
thing happen.
Fixes: f95d7a46bc ("netfilter: ctnetlink: Fix regression in CTA_HELP processing")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When invoke __nf_conntrack_helper_find, it needs the rcu lock to
protect the helper module which would not be unloaded.
Now there are two caller nf_conntrack_helper_try_module_get and
ctnetlink_create_expect which don't hold rcu lock. And the other
callers left like ctnetlink_change_helper, ctnetlink_create_conntrack,
and ctnetlink_glue_attach_expect, they already hold the rcu lock
or spin_lock_bh.
Remove the rcu lock in functions nf_ct_helper_expectfn_find_by_name
and nf_ct_helper_expectfn_find_by_symbol. Because they return one pointer
which needs rcu lock, so their caller should hold the rcu lock, not in
these two functions.
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add and use nfnl_msg_type() function to replace opencoded nfnetlink
message type. I suggested this change, Arushi Singhal made an initial
patch to address this but was missing several spots.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The expect check function __nf_ct_expect_check() asks the master_help is
necessary. So it is unnecessary to go ahead in ctnetlink_alloc_expect
when there is no help.
Actually the commit bc01befdcf ("netfilter: ctnetlink: add support for
user-space expectation helpers") permits ctnetlink create one expect
even though there is no master help. But the latter commit 3d058d7bc2
("netfilter: rework user-space expectation helper support") disables it
again.
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Mostly simple cases of overlapping changes (adding code nearby,
a function whose name changes, for example).
Signed-off-by: David S. Miller <davem@davemloft.net>
Otherwise, another CPU may access the invalid pointer. For example:
CPU0 CPU1
- rcu_read_lock();
- pfunc = _hook_;
_hook_ = NULL; -
mod unload -
- pfunc(); // invalid, panic
- rcu_read_unlock();
So we must call synchronize_rcu() to wait the rcu reader to finish.
Also note, in nf_nat_snmp_basic_fini, synchronize_rcu() will be invoked
by later nf_conntrack_helper_unregister, but I'm inclined to add a
explicit synchronize_rcu after set the nf_nat_snmp_hook to NULL. Depend
on such obscure assumptions is not a good idea.
Last, in nfnetlink_cttimeout, we use kfree_rcu to free the time object,
so in cttimeout_exit, invoking rcu_barrier() is not necessary at all,
remove it too.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
refcount_t type and corresponding API (see include/linux/refcount.h)
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.
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: Pablo Neira Ayuso <pablo@netfilter.org>
Prior to Linux 4.4, it was usually harmless to send a CTA_HELP attribute
containing the name of the current helper. That is no longer the case:
as of Linux 4.4, if ctnetlink_change_helper() returns an error from
the ct->master check, processing of the request will fail, skipping the
NFQA_EXP attribute (if present).
This patch changes the behavior to improve compatibility with user
programs that expect the kernel interface to work the way it did prior
to Linux 4.4. If a user program specifies CTA_HELP but the argument
matches the current conntrack helper name, ignore it instead of generating
an error.
Signed-off-by: Kevin Cernekee <cernekee@chromium.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The libnetfilter_conntrack userland library always sets IPS_CONFIRMED
when building a CTA_STATUS attribute. If this toggles the bit from
0->1, the parser will return an error. On Linux 4.4+ this will cause any
NFQA_EXP attribute in the packet to be ignored. This breaks conntrackd's
userland helpers because they operate on unconfirmed connections.
Instead of returning -EBUSY if the user program asks to modify an
unchangeable bit, simply ignore the change.
Also, fix the logic so that user programs are allowed to clear
the bits that they are allowed to change.
Signed-off-by: Kevin Cernekee <cernekee@chromium.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
These counters sit in hot path and do show up in perf, this is especially
true for 'found' and 'searched' which get incremented for every packet
processed.
Information like
searched=212030105
new=623431
found=333613
delete=623327
does not seem too helpful nowadays:
- on busy systems found and searched will overflow every few hours
(these are 32bit integers), other more busy ones every few days.
- for debugging there are better methods, such as iptables' trace target,
the conntrack log sysctls. Nowadays we also have perf tool.
This removes packet path stat counters except those that
are expected to be 0 (or close to 0) on a normal system, e.g.
'insert_failed' (race happened) or 'invalid' (proto tracker rejects).
The insert stat is retained for the ctnetlink case.
The found stat is retained for the tuple-is-taken check when NAT has to
determine if it needs to pick a different source address.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for your net-next
tree. Most relevant updates are the removal of per-conntrack timers to
use a workqueue/garbage collection approach instead from Florian
Westphal, the hash and numgen expression for nf_tables from Laura
Garcia, updates on nf_tables hash set to honor the NLM_F_EXCL flag,
removal of ip_conntrack sysctl and many other incremental updates on our
Netfilter codebase.
More specifically, they are:
1) Retrieve only 4 bytes to fetch ports in case of non-linear skb
transport area in dccp, sctp, tcp, udp and udplite protocol
conntrackers, from Gao Feng.
2) Missing whitespace on error message in physdev match, from Hangbin Liu.
3) Skip redundant IPv4 checksum calculation in nf_dup_ipv4, from Liping Zhang.
4) Add nf_ct_expires() helper function and use it, from Florian Westphal.
5) Replace opencoded nf_ct_kill() call in IPVS conntrack support, also
from Florian.
6) Rename nf_tables set implementation to nft_set_{name}.c
7) Introduce the hash expression to allow arbitrary hashing of selector
concatenations, from Laura Garcia Liebana.
8) Remove ip_conntrack sysctl backward compatibility code, this code has
been around for long time already, and we have two interfaces to do
this already: nf_conntrack sysctl and ctnetlink.
9) Use nf_conntrack_get_ht() helper function whenever possible, instead
of opencoding fetch of hashtable pointer and size, patch from Liping Zhang.
10) Add quota expression for nf_tables.
11) Add number generator expression for nf_tables, this supports
incremental and random generators that can be combined with maps,
very useful for load balancing purpose, again from Laura Garcia Liebana.
12) Fix a typo in a debug message in FTP conntrack helper, from Colin Ian King.
13) Introduce a nft_chain_parse_hook() helper function to parse chain hook
configuration, this is used by a follow up patch to perform better chain
update validation.
14) Add rhashtable_lookup_get_insert_key() to rhashtable and use it from the
nft_set_hash implementation to honor the NLM_F_EXCL flag.
15) Missing nulls check in nf_conntrack from nf_conntrack_tuple_taken(),
patch from Florian Westphal.
16) Don't use the DYING bit to know if the conntrack event has been already
delivered, instead a state variable to track event re-delivery
states, also from Florian.
17) Remove the per-conntrack timer, use the workqueue approach that was
discussed during the NFWS, from Florian Westphal.
18) Use the netlink conntrack table dump path to kill stale entries,
again from Florian.
19) Add a garbage collector to get rid of stale conntracks, from
Florian.
20) Reschedule garbage collector if eviction rate is high.
21) Get rid of the __nf_ct_kill_acct() helper.
22) Use ARPHRD_ETHER instead of hardcoded 1 from ARP logger.
23) Make nf_log_set() interface assertive on unsupported families.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
When dumping we already have to look at the entire table, so we might
as well toss those entries whose timeout value is in the past.
We also look at every entry during resize operations.
However, eviction there is not as simple because we hold the
global resize lock so we can't evict without adding a 'expired' list
to drop from later. Considering that resizes are very rare it doesn't
seem worth doing it.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
With stats enabled this eats 80 bytes on x86_64 per nf_conn entry, as
Eric Dumazet pointed out during netfilter workshop 2016.
Eric also says: "Another reason was the fact that Thomas was about to
change max timer range [..]" (500462a9de, 'timers: Switch to
a non-cascading wheel').
Remove the timer and use a 32bit jiffies value containing timestamp until
entry is valid.
During conntrack lookup, even before doing tuple comparision, check
the timeout value and evict the entry in case it is too old.
The dying bit is used as a synchronization point to avoid races where
multiple cpus try to evict the same entry.
Because lookup is always lockless, we need to bump the refcnt once
when we evict, else we could try to evict already-dead entry that
is being recycled.
This is the standard/expected way when conntrack entries are destroyed.
Followup patches will introduce garbage colliction via work queue
and further places where we can reap obsoleted entries (e.g. during
netlink dumps), this is needed to avoid expired conntracks from hanging
around for too long when lookup rate is low after a busy period.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
... so we don't need to touch all of these places when we get rid of the
timer in nf_conn.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently, user can add a conntrack with different l4proto via nfnetlink.
For example, original tuple is TCP while reply tuple is SCTP. This is
invalid combination, we should report EINVAL to userspace.
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
User can use NFQA_EXP to attach expectations to conntracks, but we
forget to put back nf_conntrack_expect when it is inserted successfully,
i.e. in this normal case, expect's use refcnt will be 3. So even we
unlink it and put it back later, the use refcnt is still 1, then the
memory will be leaked forever.
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The conntrack label extension is currently variable-sized, e.g. if
only 2 labels are used by iptables rules then the labels->bits[] array
will only contain one element.
We track size of each label storage area in the 'words' member.
But in nftables and openvswitch we always have to ask for worst-case
since we don't know what bit will be used at configuration time.
As most arches are 64bit we need to allocate 24 bytes in this case:
struct nf_conn_labels {
u8 words; /* 0 1 */
/* XXX 7 bytes hole, try to pack */
long unsigned bits[2]; /* 8 24 */
Make bits a fixed size and drop the words member, it simplifies
the code and only increases memory requirements on x86 when
less than 64bit labels are required.
We still only allocate the extension if its needed.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We already include netns address in the hash and compare the netns pointers
during lookup, so even if namespaces have overlapping addresses entries
will be spread across the expectation table.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We already include netns address in the hash and compare the netns pointers
during lookup, so even if namespaces have overlapping addresses entries
will be spread across the table.
Assuming 64k bucket size, this change saves 0.5 mbyte per namespace on a
64bit system.
NAT bysrc and expectation hash is still per namespace, those will
changed too soon.
Future patch will also make conntrack object slab cache global again.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Once we place all conntracks in the same hash table we must also compare
the netns pointer to skip conntracks that belong to a different namespace.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for your net-next
tree, mostly from Florian Westphal to sort out the lack of sufficient
validation in x_tables and connlabel preparation patches to add
nf_tables support. They are:
1) Ensure we don't go over the ruleset blob boundaries in
mark_source_chains().
2) Validate that target jumps land on an existing xt_entry. This extra
sanitization comes with a performance penalty when loading the ruleset.
3) Introduce xt_check_entry_offsets() and use it from {arp,ip,ip6}tables.
4) Get rid of the smallish check_entry() functions in {arp,ip,ip6}tables.
5) Make sure the minimal possible target size in x_tables.
6) Similar to #3, add xt_compat_check_entry_offsets() for compat code.
7) Check that standard target size is valid.
8) More sanitization to ensure that the target_offset field is correct.
9) Add xt_check_entry_match() to validate that matches are well-formed.
10-12) Three patch to reduce the number of parameters in
translate_compat_table() for {arp,ip,ip6}tables by using a container
structure.
13) No need to return value from xt_compat_match_from_user(), so make
it void.
14) Consolidate translate_table() so it can be used by compat code too.
15) Remove obsolete check for compat code, so we keep consistent with
what was already removed in the native layout code (back in 2007).
16) Get rid of target jump validation from mark_source_chains(),
obsoleted by #2.
17) Introduce xt_copy_counters_from_user() to consolidate counter
copying, and use it from {arp,ip,ip6}tables.
18,22) Get rid of unnecessary explicit inlining in ctnetlink for dump
functions.
19) Move nf_connlabel_match() to xt_connlabel.
20) Skip event notification if connlabel did not change.
21) Update of nf_connlabels_get() to make the upcoming nft connlabel
support easier.
23) Remove spinlock to read protocol state field in conntrack.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
nla_data() is now aligned on a 64-bit area.
A temporary version (nla_put_be64_32bit()) is added for nla_put_net64().
This function is removed in the next patch.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Calm down gcc warnings:
net/netfilter/nf_conntrack_netlink.c:529:15: warning: 'ctnetlink_proto_size' defined but not used [-Wunused-function]
static size_t ctnetlink_proto_size(const struct nf_conn *ct)
^
net/netfilter/nf_conntrack_netlink.c:546:15: warning: 'ctnetlink_acct_size' defined but not used [-Wunused-function]
static size_t ctnetlink_acct_size(const struct nf_conn *ct)
^
net/netfilter/nf_conntrack_netlink.c:556:12: warning: 'ctnetlink_secctx_size' defined but not used [-Wunused-function]
static int ctnetlink_secctx_size(const struct nf_conn *ct)
^
net/netfilter/nf_conntrack_netlink.c:572:15: warning: 'ctnetlink_timestamp_size' defined but not used [-Wunused-function]
static size_t ctnetlink_timestamp_size(const struct nf_conn *ct)
^
So gcc compiles them out when CONFIG_NF_CONNTRACK_EVENTS and
CONFIG_NETFILTER_NETLINK_GLUE_CT are not set.
Fixes: 4054ff4545 ("netfilter: ctnetlink: remove unnecessary inlining")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Many of these functions are called from control plane path. Move
ctnetlink_nlmsg_size() under CONFIG_NF_CONNTRACK_EVENTS to avoid a
compilation warning when CONFIG_NF_CONNTRACK_EVENTS=n.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Florian Westphal