Commit graph

16141 commits

Author SHA1 Message Date
Johannes Berg
83a5cbf73a mac80211: defer TX agg session teardown to work
Since we want the code to be able to sleep
in the future, it must not be called from
the timer directly. To achieve that, simply
call the function drivers would call, and
also use RCU in the timer to get the struct
so we don't need to rely on the spinlock in
the future.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:28 -04:00
Johannes Berg
a93e364430 mac80211: change RX aggregation locking
To prepare for allowing drivers to sleep in
ampdu_action, change the locking in the RX
aggregation code to use a mutex, so that it
would already allow drivers to sleep. But
explicitly disable BHs around the callback
for now since the TX part cannot yet sleep,
and drivers' locking might require it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:28 -04:00
Johannes Berg
f955ebb447 mac80211: fix RX aggregation timer
I noticed that when there was _no_ traffic at
all on a given aggregation session, it would
never time out. This won't happen unless you
forced creating a session, but fix it anyway.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:28 -04:00
Johannes Berg
7c3b1dd8f4 mac80211: defer RX agg session teardown to work
Since we want the code to be able to sleep
in the future, it must not be called from
the timer directly. To prepare, move it out
into the aggregation work.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:28 -04:00
Johannes Berg
67c282c00c mac80211: move BA session work
Move the block-ack session works into common
code, since it will be needed for RX agg too
in the next patches.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:27 -04:00
Johannes Berg
0ab337032a mac80211: make TX aggregation start/stop request async
When the driver or rate control requests starting
or stopping an aggregation session, that currently
causes a direct callback into the driver, which
could potentially cause locking problems. Also,
the functions need to be callable from contexts
that cannot sleep, and thus will interfere with
making the ampdu_action callback sleeping.

To address these issues, add a new work item for
each station that will process any start or stop
requests out of line.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:27 -04:00
Johannes Berg
a6a67db2bc mac80211: refcount aggregation queue stop
mac80211 currently maintains the ampdu_lock to
avoid starting a queue due to one aggregation
session while another aggregation session needs
the queue stopped.

We can do better, however, and instead refcount
the queue stops for this particular purpose,
thus removing the need for the lock. This will
help making ampdu_action able to sleep.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:27 -04:00
Johannes Berg
5d22c89b9b mac80211: remove non-irqsafe aggregation callbacks
The non-irqsafe aggregation start/stop done
callbacks are currently only used by ath9k_htc,
and can cause callbacks into the driver again.
This might lead to locking issues, which will
only get worse as we modify locking. To avoid
trouble, remove the non-irqsafe versions and
change ath9k_htc to use those instead.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:27 -04:00
Johannes Berg
a622ab72b4 mac80211: use RCU for TX aggregation
Currently we allocate some memory for each TX
aggregation session and additionally keep a
state bitmap indicating the state it is in.
By using RCU to protect the pointer, moving
the state into the structure and some locking
trickery we can avoid locking when the TX agg
session is fully operational.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:27 -04:00
Johannes Berg
a87f736d94 mac80211: use RCU for RX aggregation
Currently we allocate some memory for each RX
aggregation session and additionally keep a
flag indicating whether or not it is valid.
By using RCU to protect the pointer and making
sure that the memory is fully set up before it
becomes visible to the RX path, we can remove
the need for the bool that indicates validity,
as well as for locking on the RX path since it
is always synchronised against itself, and we
can guarantee that all other modifications are
done when the structure is not visible to the
RX path.

The net result is that since we remove locking
requirements from the RX path, we can in the
future use any kind of lock for the setup and
teardown code paths.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:27 -04:00
Johannes Berg
c1475ca99e mac80211: move aggregation callback processing
This moves the aggregation callback processing
to the per-sdata skb queue and a work function
rather than the tasklet.

Unfortunately, this means that it extends the
pkt_type hack to that skb queue. However, it
will enable making ampdu_action API changes
gradually, my current plan is to get rid of
this again by forcing drivers to only return
from ampdu_action() when everything is done,
thus removing the callbacks completely.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:27 -04:00
Johannes Berg
344eec67c7 mac80211: move blockack stop due to fragmentation
There's a corner case where we receive a fragmented
frame during a blockack session, in which case we
will terminate that session. To simplify future work
in this area that will culminate in allowing the
driver callbacks for aggregation to sleep, move the
processing of this case out of the RX path into the
interface work.

This will simplify future work because the new place
for this code doesn't require that the function will
always be atomic, which the RX path needs.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:27 -04:00
Johannes Berg
bed7ee6e44 mac80211: always process blockack action from workqueue
To prepare for making the ampdu_action callback
sleep, make mac80211 always process blockack
action frames from the skb queue. This gets rid
of the current special case for managed mode
interfaces as well.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:26 -04:00
Johannes Berg
77a121c3a8 mac80211: pull mgmt frame rx into rx handler
Some code is duplicated between ibss, mesh and
managed mode regarding the queueing of management
frames. Since all modes now use a common skb
queue and a common work function, we can pull
the queueing code into the rx handler directly
and remove the duplicated length checks etc.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:26 -04:00
Johannes Berg
36b3a628a4 mac80211: common work skb freeing
All the management processing functions free the
skb after they are done, so this can be done in
the new common code instead.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:39:26 -04:00
Johannes Berg
1fa57d0173 mac80211: use common work function
Even with the previous patch, IBSS, managed
and mesh modes all attach their own work
function to the shared work struct, which
means some duplicated code. Change that to
only have a frame processing function and a
further work function for each of them and
share some common code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:38:17 -04:00
Johannes Berg
64592c8fc0 mac80211: use common work struct
IBSS, managed and mesh modes all have their
own work struct, and in the future we want
to also use it in other modes to process
frames from the now common skb queue.

This also makes the skb queue and work safe
to use from other interface types.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:38:17 -04:00
Johannes Berg
35f20c14a1 mac80211: use common skb queue
IBSS, managed and mesh modes all have an
skb queue, and in the future we want to
also use it in other modes, so make them
all use a common skb queue already.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:38:17 -04:00
Johannes Berg
2a419056c1 mac80211: simplify station/aggregation code
A number of places use RCU locking for accessing
the station list, even though they do not need
to. Use mutex locking instead to prepare for the
locking changes I want to make. The mlme code is
also using a WLAN_STA_DISASSOC flag that has the
same meaning as WLAN_STA_BLOCK_BA, so use that.

While doing so, combine places where we loop
over stations twice, and optimise away some of
the loops by checking if the hardware supports
aggregation at all first.

Also fix a more theoretical race condition: right
now we could resume, set up an aggregation session,
and right after tear it down again due to the code
that is needed for hardware reconfiguration here.
Also mark add a comment to that code marking it as
a workaround.

Finally, remove a pointless aggregation disabling
loop when an interface is stopped, directly after
that we remove all stations from it which will also
disable all aggregation sessions that may still be
active, and does so in a race-free way unlike the
current loop that doesn't block new sessions.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:38:16 -04:00
Johannes Berg
9d38d85de0 cfg80211/mac80211: allow action frame TX/RX in IBSS
When in IBSS mode, currently action frame TX and RX
cannot be used. Allow using it to talk to any peer,
or for public action frames. Also, while at it,
restructure the code in mac80211 to make it easier
to add this for other interface types in the future.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-14 15:38:16 -04:00
Shan Wei
0b041f8d1e netfilter: defrag: kill unused work parameter of frag_kfree_skb()
The parameter (work) is unused, remove it.
Reported from Eric Dumazet.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-14 16:30:47 +02:00
Shan Wei
841a5940eb netfilter: defrag: remove one redundant atomic ops
Instead of doing one atomic operation per frag, we can factorize them.
Reported from Eric Dumazet.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-14 16:28:23 +02:00
Shan Wei
c86ee67c7c netfilter: kill redundant check code in which setting ip_summed value
If the returned csum value is 0, We has set ip_summed with
CHECKSUM_UNNECESSARY flag in __skb_checksum_complete_head().

So this patch kills the check and changes to return to upper
caller directly.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-14 16:20:02 +02:00
Eric Dumazet
f5c5440d40 netfilter: nfnetlink_log: RCU conversion, part 2
- must use atomic_inc_not_zero() in instance_lookup_get()

- must use hlist_add_head_rcu() instead of hlist_add_head()

- must use hlist_del_rcu() instead of hlist_del()

- Introduce NFULNL_COPY_DISABLED to stop lockless reader from using an
instance, before we do final instance_put() on it.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-14 16:15:23 +02:00
Eric Dumazet
e8d15e6460 net: rxhash already set in __copy_skb_header
No need to copy rxhash again in __skb_clone()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-13 17:16:54 -07:00
John Fastabend
e897082fe7 net: fix deliver_no_wcard regression on loopback device
deliver_no_wcard is not being set in skb_copy_header.
In the skb_cloned case it is not being cleared and
may cause the skb to be dropped when the loopback device
pushes it back up the stack.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-13 17:12:40 -07:00
Ben Hutchings
0b5c25e8ac irttp: Print device parameters and statistics as unsigned
Device statistics have type unsigned long and several of the
device-specific parameters printed here have type __u32.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-12 18:18:33 -07:00
Ben Hutchings
be1f3c2c02 net: Enable 64-bit net device statistics on 32-bit architectures
Use struct rtnl_link_stats64 as the statistics structure.

On 32-bit architectures, insert 32 bits of padding after/before each
field of struct net_device_stats to make its layout compatible with
struct rtnl_link_stats64.  Add an anonymous union in net_device; move
stats into the union and add struct rtnl_link_stats64 stats64.

Add net_device_ops::ndo_get_stats64, implementations of which will
return a pointer to struct rtnl_link_stats64.  Drivers that implement
this operation must not update the structure asynchronously.

Change dev_get_stats() to call ndo_get_stats64 if available, and to
return a pointer to struct rtnl_link_stats64.  Change callers of
dev_get_stats() accordingly.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-12 15:51:22 -07:00
Daniel Turull
43d28b6515 pktgen: increasing transmission granularity
This patch increases the granularity of the rate generated by pktgen.
The previous version of pktgen uses micro seconds (udelay) resolution when it
was delayed causing gaps in the rates. It is changed to nanosecond (ndelay).
Now any rate is possible.

Also it allows to set, the desired rate in Mb/s or packets per second.

The documentation has been updated.

Signed-off-by: Daniel Turull <daniel.turull@gmail.com>
Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-11 18:37:09 -07:00
Eric Dumazet
0c78a92fbd econet: fix locking
econet lacks proper locking. It holds econet_lock only when inserting or
deleting an entry in econet_sklist, not during lookups.

- convert econet_lock from rwlock to spinlock

- use econet_lock in ec_listening_socket() lookup

- use appropriate sock_hold() / sock_put() to avoid corruptions.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-11 18:37:08 -07:00
Eric Dumazet
c7de2cf053 pkt_sched: gen_kill_estimator() rcu fixes
gen_kill_estimator() API is incomplete or not well documented, since
caller should make sure an RCU grace period is respected before
freeing stats_lock.

This was partially addressed in commit 5d944c640b
(gen_estimator: deadlock fix), but same problem exist for all
gen_kill_estimator() users, if lock they use is not already RCU
protected.

A code review shows xt_RATEEST.c, act_api.c, act_police.c have this
problem. Other are ok because they use qdisc lock, already RCU
protected.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-11 18:37:08 -07:00
David S. Miller
62522d36d7 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-06-11 13:32:31 -07:00
David S. Miller
14599f1e34 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6
Conflicts:
	drivers/net/wireless/wl12xx/wl1271.h
	drivers/net/wireless/wl12xx/wl1271_cmd.h
2010-06-11 11:34:06 -07:00
Changli Gao
d8d1f30b95 net-next: remove useless union keyword
remove useless union keyword in rtable, rt6_info and dn_route.

Since there is only one member in a union, the union keyword isn't useful.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-10 23:31:35 -07:00
Daniel Turull
07a0f0f07a pktgen: Fix accuracy of inter-packet delay.
This patch correct a bug in the delay of pktgen. 
It makes sure the inter-packet interval is accurate.

Signed-off-by: Daniel Turull <daniel.turull@gmail.com>
Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-10 23:08:11 -07:00
Eric Dumazet
ae638c47dc pkt_sched: gen_estimator: add a new lock
gen_kill_estimator() / gen_new_estimator() is not always called with
RTNL held.

net/netfilter/xt_RATEEST.c is one user of these API that do not hold
RTNL, so random corruptions can occur between "tc" and "iptables".

Add a new fine grained lock instead of trying to use RTNL in netfilter.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-10 22:53:52 -07:00
Eric Dumazet
592fcb9dfa ip: ip_ra_control() rcu fix
commit 66018506e1 (ip: Router Alert RCU conversion) introduced RCU
lookups to ip_call_ra_chain(). It missed proper deinit phase :
When ip_ra_control() deletes an ip_ra_chain, it should make sure
ip_call_ra_chain() users can not start to use socket during the rcu
grace period. It should also delay the sock_put() after the grace
period, or we risk a premature socket freeing and corruptions, as
raw sockets are not rcu protected yet.

This delay avoids using expensive atomic_inc_not_zero() in
ip_call_ra_chain().

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-10 22:47:08 -07:00
John Fastabend
597a264b1a net: deliver skbs on inactive slaves to exact matches
Currently, the accelerated receive path for VLAN's will
drop packets if the real device is an inactive slave and
is not one of the special pkts tested for in
skb_bond_should_drop().  This behavior is different then
the non-accelerated path and for pkts over a bonded vlan.

For example,

vlanx -> bond0 -> ethx

will be dropped in the vlan path and not delivered to any
packet handlers at all.  However,

bond0 -> vlanx -> ethx

and

bond0 -> ethx

will be delivered to handlers that match the exact dev,
because the VLAN path checks the real_dev which is not a
slave and netif_recv_skb() doesn't drop frames but only
delivers them to exact matches.

This patch adds a sk_buff flag which is used for tagging
skbs that would previously been dropped and allows the
skb to continue to skb_netif_recv().  Here we add
logic to check for the deliver_no_wcard flag and if it
is set only deliver to handlers that match exactly.  This
makes both paths above consistent and gives pkt handlers
a way to identify skbs that come from inactive slaves.
Without this patch in some configurations skbs will be
delivered to handlers with exact matches and in others
be dropped out right in the vlan path.

I have tested the following 4 configurations in failover modes
and load balancing modes.

# bond0 -> ethx

# vlanx -> bond0 -> ethx

# bond0 -> vlanx -> ethx

# bond0 -> ethx
            |
  vlanx -> --

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-10 22:23:34 -07:00
Eric Dumazet
00d9d6a185 ipv6: fix ICMP6_MIB_OUTERRORS
In commit 1f8438a853 (icmp: Account for ICMP out errors), I did a typo
on IPV6 side, using ICMP6_MIB_OUTMSGS instead of ICMP6_MIB_OUTERRORS

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-09 18:39:27 -07:00
Eric Dumazet
96b52e61be ipv6: mcast: RCU conversions
- ipv6_sock_mc_join() : doesnt touch dev refcount

- ipv6_sock_mc_drop() : doesnt touch dev/idev refcounts

- ip6_mc_find_dev() becomes ip6_mc_find_dev_rcu() (called from rcu),
                    and doesnt touch dev/idev refcounts

- ipv6_sock_mc_close() : doesnt touch dev/idev refcounts

- ip6_mc_source() uses ip6_mc_find_dev_rcu()

- ip6_mc_msfilter() uses ip6_mc_find_dev_rcu()

- ip6_mc_msfget() uses ip6_mc_find_dev_rcu()

- ipv6_dev_mc_dec(), ipv6_chk_mcast_addr(),
  igmp6_event_query(), igmp6_event_report(),
  mld_sendpack(), igmp6_send() dont touch idev refcount

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-09 18:06:14 -07:00
Eric Dumazet
cfa087f689 icmp: RCU conversion in icmp_address_reply()
- rcu_read_lock() already held by caller
- use __in_dev_get_rcu() instead of in_dev_get() / in_dev_put()
- remove goto out;

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-09 18:06:13 -07:00
David S. Miller
ebedb22d2b Merge branch 'num_rx_queues' of git://kernel.ubuntu.com/rtg/net-2.6 2010-06-09 16:28:25 -07:00
Dan Carpenter
aea34e7ae7 caif: fix a couple range checks
The extra ! character means that these conditions are always false.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-09 16:18:53 -07:00
Jiri Pirko
88e7594a97 phonet: use call_rcu for phonet device free
Use call_rcu rather than synchronize_rcu.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-09 16:14:25 -07:00
Tim Gardner
08c801f8d4 net: Print num_rx_queues imbalance warning only when there are allocated queues
BugLink: http://bugs.launchpad.net/bugs/591416

There are a number of network drivers (bridge, bonding, etc) that are not yet
receive multi-queue enabled and use alloc_netdev(), so don't print a
num_rx_queues imbalance warning in that case.

Also, only print the warning once for those drivers that _are_ multi-queue
enabled.

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
2010-06-09 13:46:03 -06:00
David S. Miller
327723edeb Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 2010-06-09 11:13:23 -07:00
Eric Dumazet
bed1be2086 netfilter: nfnetlink_log: RCU conversion
- instances_lock becomes a spinlock
- lockless lookups

While nfnetlink_log probably not performance critical, using less
rwlocks in our code is always welcomed...

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-09 18:14:58 +02:00
Eric Dumazet
c463ac9723 netfilter: nfnetlink_queue: some optimizations
- Use an atomic_t for id_sequence to avoid a spin_lock/spin_unlock pair

- Group highly modified struct nfqnl_instance fields together

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-09 18:07:06 +02:00
Eric Dumazet
144ad2a6c5 netfilter: ip6_queue: rwlock to spinlock conversion
Converts queue_lock rwlock to a spinlock.

(readlocked part can be changed by reads of integer values)

One atomic operation instead of four per ipq_enqueue_packet() call.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-09 16:25:08 +02:00
Sven Wegener
aea9d711f3 ipvs: Add missing locking during connection table hashing and unhashing
The code that hashes and unhashes connections from the connection table
is missing locking of the connection being modified, which opens up a
race condition and results in memory corruption when this race condition
is hit.

Here is what happens in pretty verbose form:

CPU 0					CPU 1
------------				------------
An active connection is terminated and
we schedule ip_vs_conn_expire() on this
CPU to expire this connection.

					IRQ assignment is changed to this CPU,
					but the expire timer stays scheduled on
					the other CPU.

					New connection from same ip:port comes
					in right before the timer expires, we
					find the inactive connection in our
					connection table and get a reference to
					it. We proper lock the connection in
					tcp_state_transition() and read the
					connection flags in set_tcp_state().

ip_vs_conn_expire() gets called, we
unhash the connection from our
connection table and remove the hashed
flag in ip_vs_conn_unhash(), without
proper locking!

					While still holding proper locks we
					write the connection flags in
					set_tcp_state() and this sets the hashed
					flag again.

ip_vs_conn_expire() fails to expire the
connection, because the other CPU has
incremented the reference count. We try
to re-insert the connection into our
connection table, but this fails in
ip_vs_conn_hash(), because the hashed
flag has been set by the other CPU. We
re-schedule execution of
ip_vs_conn_expire(). Now this connection
has the hashed flag set, but isn't
actually hashed in our connection table
and has a dangling list_head.

					We drop the reference we held on the
					connection and schedule the expire timer
					for timeouting the connection on this
					CPU. Further packets won't be able to
					find this connection in our connection
					table.

					ip_vs_conn_expire() gets called again,
					we think it's already hashed, but the
					list_head is dangling and while removing
					the connection from our connection table
					we write to the memory location where
					this list_head points to.

The result will probably be a kernel oops at some other point in time.

This race condition is pretty subtle, but it can be triggered remotely.
It needs the IRQ assignment change or another circumstance where packets
coming from the same ip:port for the same service are being processed on
different CPUs. And it involves hitting the exact time at which
ip_vs_conn_expire() gets called. It can be avoided by making sure that
all packets from one connection are always processed on the same CPU and
can be made harder to exploit by changing the connection timeouts to
some custom values.

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Cc: stable@kernel.org
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-09 16:10:57 +02:00