When a helper module is unloaded all conntracks refering to it have their
helper pointer NULLed out, leading to lots of races. In most places this
can be fixed by proper use of RCU (they do already check for != NULL,
but in a racy way), additionally nf_conntrack_expect_related needs to
bail out when no helper is present.
Also remove two paranoid BUG_ONs in nf_conntrack_proto_gre that are racy
and not worth fixing.
Signed-off-by: Patrick McHarrdy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the helper module is removed for a master connection that has a
fulfilled expectation, but has already timed out and got removed from
the hash tables, nf_conntrack_helper_unregister can't find the master
connection to unset the helper, causing a use-after-free when the
expected connection is destroyed and releases the last reference to
the master.
The helper destroy callback was introduced for the PPtP helper to clean
up expectations and expected connections when the master connection
times out, but doing this from destroy_conntrack only works for
unfulfilled expectations since expected connections hold a reference
to the master, preventing its destruction. Move the destroy callback to
the timeout function, which fixes both problems.
Reported/tested by Gabor Burjan <buga@buvoshetes.hu>.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some helpers (eg. ftp) assume that private area in conntrack is
filled with zero. It should be cleared when helper is changed.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The destructor per conntrack is unnecessary, then this replaces it with
system wide destructor.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now it uses jhash, but using jhash2 would be around 3-4 times faster
(on P4).
Signed-off-by: Sami Farin <safari-netfilter@safari.iki.fi>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove ugly special-casing of nf_conntrack_l4proto_generic, all it
wants is its sysctl tables registered, so do that explicitly in an
init function and move the remaining protocol initialization and
cleanup code to nf_conntrack_proto.c as well.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the quite common 'skb->nh.raw - skb->data' sequence.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The nf_conntrack_netlink config option is named CONFIG_NF_CT_NETLINK,
but multiple files use CONFIG_IP_NF_CONNTRACK_NETLINK or
CONFIG_NF_CONNTRACK_NETLINK for ifdefs.
Fix this and reformat all CONFIG_NF_CT_NETLINK ifdefs to only use a line.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix {nf,ip}_ct_iterate_cleanup unconfirmed list handling:
- unconfirmed entries can not be killed manually, they are removed on
confirmation or final destruction of the conntrack entry, which means
we might iterate forever without making forward progress.
This can happen in combination with the conntrack event cache, which
holds a reference to the conntrack entry, which is only released when
the packet makes it all the way through the stack or a different
packet is handled.
- taking references to an unconfirmed entry and using it outside the
locked section doesn't work, the list entries are not refcounted and
another CPU might already be waiting to destroy the entry
What the code really wants to do is make sure the references of the hash
table to the selected conntrack entries are released, so they will be
destroyed once all references from skbs and the event cache are dropped.
Since unconfirmed entries haven't even entered the hash yet, simply mark
them as dying and skip confirmation based on that.
Reported and tested by Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
NF_CT_STAT_INC assumes rcu_read_lock in nf_hook_slow disables
preemption as well, making it legal to use __get_cpu_var without
disabling preemption manually. The assumption is not correct anymore
with preemptable RCU, additionally we need to protect against softirqs
when not holding nf_conntrack_lock.
Add NF_CT_STAT_INC_ATOMIC macro, which disables local softirqs,
and use where necessary.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace preempt_{enable,disable} based RCU by proper use of the
RCU API and add missing rcu_read_lock/rcu_read_unlock calls in
all paths not obviously only used within packet process context
(nfnetlink_conntrack).
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use rcu_assign_pointer/rcu_dereference for ip_ct_attach pointer instead
of self-made RCU and use rcu_read_lock to make sure the conntrack module
doesn't disappear below us while calling it, since this function can be
called from outside the netfilter hooks.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace all uses of kmem_cache_t with struct kmem_cache.
The patch was generated using the following script:
#!/bin/sh
#
# Replace one string by another in all the kernel sources.
#
set -e
for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
quilt add $file
sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
mv /tmp/$$ $file
quilt refresh
done
The script was run like this
sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix non-ANSI function declaration:
net/netfilter/nf_conntrack_core.c:1096:25: warning: non-ANSI function declaration of function 'nf_conntrack_flush'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
- move EXPORT_SYMBOL next to exported symbol
- use EXPORT_SYMBOL_GPL since this is what the original code used
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add nf_conntrack port of the PPtP conntrack/NAT helper. Since there seems
to be no IPv6-capable PPtP implementation the helper only support IPv4.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add NAT support for nf_conntrack. Joint work of Jozsef Kadlecsik,
Yasuyuki Kozakai, Martin Josefsson and myself.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some helpers (namely H.323) manually assign further helpers to expected
connections. This is not possible with nf_conntrack anymore since we
need to know whether a helper is used at allocation time.
Handle the helper assignment centrally, which allows to perform the
correct allocation and as a nice side effect eliminates the need
for the H.323 helper to fiddle with nf_conntrack_lock.
Mid term the allocation scheme really needs to be redesigned since
we do both the helper and expectation lookup _twice_ for every new
connection.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Resync with Al Viro's ip_conntrack annotations and fix a missed
spot in ip_nat_proto_icmp.c.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Only update the conntrack timer if there's been at least HZ jiffies since
the last update. Reduces the number of del_timer/add_timer cycles from one
per packet to one per connection per second (plus once for each state change
of a connection)
Should handle timer wraparounds and connection timeout changes.
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Remove the usage of ASSERT_READ_LOCK/ASSERT_WRITE_LOCK in nf_conntrack,
it didn't do anything, it was just an empty define and it uglified the code.
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Add some more sanity checks when registering/unregistering l3/l4 protocols.
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Rename 'struct nf_conntrack_protocol' to 'struct nf_conntrack_l4proto' in
order to help distinguish it from 'struct nf_conntrack_l3proto'. It gets
rather confusing with 'nf_conntrack_protocol'.
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Place rarely written variables in the read-mostly section by using
__read_mostly
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This patch splits out L3/L4 protocol handling into its own file
nf_conntrack_proto.c
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This patch splits out the event cache into its own file
nf_conntrack_ecache.c
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This patch splits out handling of helpers into its own file
nf_conntrack_helper.c
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This patch splits out expectation handling into its own file
nf_conntrack_expect.c
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
All users of __{ip,nf}_conntrack_expect_find() don't expect that
it increments the reference count of expectation.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The found helper cannot be assigned to conntrack after unlocking
nf_conntrack_lock. This tries to find helper to assign again.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add missing unlock in get_next_corpse() in nf_conntrack. It was missed
during the removal of listhelp.h . Also remove an unneeded use of
nf_ct_tuplehash_to_ctrack() in the same function.
Should be applied before 2.6.19 is released.
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
On SMP environments the maximum number of conntracks can be overpassed
under heavy stress situations due to an existing race condition.
CPU A CPU B
atomic_read() ...
early_drop() ...
... atomic_read()
allocate conntrack allocate conntrack
atomic_inc() atomic_inc()
This patch moves the counter incrementation before the early drop stage.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Kill listhelp.h and use the list.h functions instead.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change some netfilter tunables to __read_mostly. Also fixed some
incorrect file reference comments while I was in there.
(this will be my last __read_mostly patch unless someone points out
something else that needs it)
Signed-off-by: Brian Haley <brian.haley@hp.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a secmark field to IP and NF conntracks, so that security markings
on packets can be copied to their associated connections, and also
copied back to packets as required. This is similar to the network
mark field currently used with conntrack, although it is intended for
enforcement of security policy rather than network policy.
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a flag in a connection status to have a non updated timeout.
This permits to have connection that automatically die at a given
time.
Signed-off-by: Eric Leblond <eric@inl.fr>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
If nf_ct_l3proto_find_get() fails to get the refcount of
nf_ct_l3proto_generic, nf_ct_l3proto_put() will drop the refcount
too far.
This gets rid of '.me = THIS_MODULE' of nf_ct_l3proto_generic so that
nf_ct_l3proto_find_get() doesn't try to get refcount of it.
It's OK because its symbol is usable until nf_conntrack.ko is unloaded.
This also kills unnecessary NULL pointer check as well.
__nf_ct_proto_find() allways returns non-NULL pointer.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
