Commit Graph

258 Commits

Author SHA1 Message Date
David S. Miller dbbe68bb12 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-01-04 11:57:25 -08:00
Joel Sing 9fc3bbb4a7 ipv4/route.c: respect prefsrc for local routes
The preferred source address is currently ignored for local routes,
which results in all local connections having a src address that is the
same as the local dst address. Fix this by respecting the preferred source
address when it is provided for local routes.

This bug can be demonstrated as follows:

 # ifconfig dummy0 192.168.0.1
 # ip route show table local | grep local.*dummy0
 local 192.168.0.1 dev dummy0  proto kernel  scope host  src 192.168.0.1
 # ip route change table local local 192.168.0.1 dev dummy0 \
     proto kernel scope host src 127.0.0.1
 # ip route show table local | grep local.*dummy0
 local 192.168.0.1 dev dummy0  proto kernel  scope host  src 127.0.0.1

We now establish a local connection and verify the source IP
address selection:

 # nc -l 192.168.0.1 3128 &
 # nc 192.168.0.1 3128 &
 # netstat -ant | grep 192.168.0.1:3128.*EST
 tcp        0      0 192.168.0.1:3128        192.168.0.1:33228 ESTABLISHED
 tcp        0      0 192.168.0.1:33228       192.168.0.1:3128  ESTABLISHED

Signed-off-by: Joel Sing <jsing@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-04 11:35:12 -08:00
David S. Miller 17f7f4d9fc Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/ipv4/fib_frontend.c
2010-12-26 22:37:05 -08:00
Eric Dumazet fc75fc8339 ipv4: dont create routes on down devices
In ip_route_output_slow(), instead of allowing a route to be created on
a not UPed device, report -ENETUNREACH immediately.

# ip tunnel add mode ipip remote 10.16.0.164 local
10.16.0.72 dev eth0
# (Note : tunl1 is down)
# ping -I tunl1 10.1.2.3
PING 10.1.2.3 (10.1.2.3) from 192.168.18.5 tunl1: 56(84) bytes of data.
(nothing)
# ./a.out tunl1
# ip tunnel del tunl1
Message from syslogd@shelby at Dec 22 10:12:08 ...
  kernel: unregister_netdevice: waiting for tunl1 to become free.
Usage count = 3

After patch:
# ping -I tunl1 10.1.2.3
connect: Network is unreachable

Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-25 20:05:31 -08:00
David S. Miller 6561a3b12d ipv4: Flush per-ns routing cache more sanely.
Flush the routing cache only of entries that match the
network namespace in which the purge event occurred.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
2010-12-20 10:37:19 -08:00
David S. Miller d33e455337 net: Abstract default MTU metric calculation behind an accessor.
Like RTAX_ADVMSS, make the default calculation go through a dst_ops
method rather than caching the computation in the routing cache
entries.

Now dst metrics are pretty much left as-is when new entries are
created, thus optimizing metric sharing becomes a real possibility.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-14 13:01:14 -08:00
David S. Miller 0dbaee3b37 net: Abstract default ADVMSS behind an accessor.
Make all RTAX_ADVMSS metric accesses go through a new helper function,
dst_metric_advmss().

Leave the actual default metric as "zero" in the real metric slot,
and compute the actual default value dynamically via a new dst_ops
AF specific callback.

For stacked IPSEC routes, we use the advmss of the path which
preserves existing behavior.

Unlike ipv4/ipv6, DecNET ties the advmss to the mtu and thus updates
advmss on pmtu updates.  This inconsistency in advmss handling
results in more raw metric accesses than I wish we ended up with.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-13 12:52:14 -08:00
David S. Miller 323e126f0c ipv4: Don't pre-seed hoplimit metric.
Always go through a new ip4_dst_hoplimit() helper, just like ipv6.

This allowed several simplifications:

1) The interim dst_metric_hoplimit() can go as it's no longer
   userd.

2) The sysctl_ip_default_ttl entry no longer needs to use
   ipv4_doint_and_flush, since the sysctl is not cached in
   routing cache metrics any longer.

3) ipv4_doint_and_flush no longer needs to be exported and
   therefore can be marked static.

When ipv4_doint_and_flush_strategy was removed some time ago,
the external declaration in ip.h was mistakenly left around
so kill that off too.

We have to move the sysctl_ip_default_ttl declaration into
ipv4's route cache definition header net/route.h, because
currently net/ip.h (where the declaration lives now) has
a back dependency on net/route.h

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-12 22:08:17 -08:00
David S. Miller 5170ae824d net: Abstract RTAX_HOPLIMIT metric accesses behind helper.
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-12 21:35:57 -08:00
David S. Miller defb3519a6 net: Abstract away all dst_entry metrics accesses.
Use helper functions to hide all direct accesses, especially writes,
to dst_entry metrics values.

This will allow us to:

1) More easily change how the metrics are stored.

2) Implement COW for metrics.

In particular this will help us put metrics into the inetpeer
cache if that is what we end up doing.  We can make the _metrics
member a pointer instead of an array, initially have it point
at the read-only metrics in the FIB, and then on the first set
grab an inetpeer entry and point the _metrics member there.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
2010-12-09 10:46:36 -08:00
David S. Miller b534ecf1cd inetpeer: Make inet_getpeer() take an inet_peer_adress_t pointer.
And make an inet_getpeer_v4() helper, update callers.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-30 11:54:19 -08:00
Changli Gao 5811662b15 net: use the macros defined for the members of flowi
Use the macros defined for the members of flowi to clean the code up.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-17 12:27:45 -08:00
David S. Miller c753796769 ipv4: Make rt->fl.iif tests lest obscure.
When we test rt->fl.iif against zero, we're seeing if it's
an output or an input route.

Make that explicit with some helper functions.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-11 17:07:48 -08:00
Eric Dumazet 72cdd1d971 net: get rid of rtable->idev
It seems idev field in struct rtable has no special purpose, but adding
extra atomic ops.

We hold refcounts on the device itself (using percpu data, so pretty
cheap in current kernel).

infiniband case is solved using dst.dev instead of idev->dev

Removal of this field means routing without route cache is now using
shared data, percpu data, and only potential contention is a pair of
atomic ops on struct neighbour per forwarded packet.

About 5% speedup on routing test.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-11 10:29:40 -08:00
Eric Dumazet 1c31720a74 ipv4: add __rcu annotations to routes.c
Add __rcu annotations to :
        (struct dst_entry)->rt_next
        (struct rt_hash_bucket)->chain

And use appropriate rcu primitives to reduce sparse warnings if
CONFIG_SPARSE_RCU_POINTER=y

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-27 11:37:31 -07:00
Eric Dumazet 27b75c95f1 net: avoid RCU for NOCACHE dst
There is no point using RCU for dst we allocate for a very short time
(used once).

Change dst_release() to take DST_NOCACHE into account, but also change
skb_dst_set_noref() to force a refcount increment for such dst.

This is a _huge_ gain, because we dont waste memory to store xx thousand
of dsts. Instead of queueing them to RCU, we can free them instantly.

CPU caches can stay hot, re-using same memory blocks to hold temporary
dsts.

Note : remove unneeded smp_mb__before_atomic_dec(); in dst_release(),
since atomic_dec_return() implies a full memory barrier.

Stress test, 160.000.000 udp frames sent, IP route cache disabled
(DDOS).

Before:

real    0m38.091s
user    0m13.189s
sys     7m53.018s

After:

real	0m29.946s
user	0m12.157s
sys	7m40.605s

For reference, if IP route cache was enabled :

real	0m32.030s
user	0m10.521s
sys	8m15.243s

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-20 03:02:23 -07:00
Andy Walls 27a954bd56 IPv4: route.c: Change checks against 0xffffffff to ipv4_is_lbcast()
Change a few checks against the hardcoded broadcast address,
0xffffffff, to ipv4_is_lbcast().  Remove some existing checks
using ipv4_is_lbcast() that are now obviously superfluous.

Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-18 07:22:50 -07:00
Eric Dumazet fc66f95c68 net dst: use a percpu_counter to track entries
struct dst_ops tracks number of allocated dst in an atomic_t field,
subject to high cache line contention in stress workload.

Switch to a percpu_counter, to reduce number of time we need to dirty a
central location. Place it on a separate cache line to avoid dirtying
read only fields.

Stress test :

(Sending 160.000.000 UDP frames,
IP route cache disabled, dual E5540 @2.53GHz,
32bit kernel, FIB_TRIE, SLUB/NUMA)

Before:

real    0m51.179s
user    0m15.329s
sys     10m15.942s

After:

real	0m45.570s
user	0m15.525s
sys	9m56.669s

With a small reordering of struct neighbour fields, subject of a
following patch, (to separate refcnt from other read mostly fields)

real	0m41.841s
user	0m15.261s
sys	8m45.949s

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-11 13:06:53 -07:00
Dimitris Michailidis 8391d07b80 ipv4: Remove leftover rcu_read_unlock calls from __mkroute_output()
Commit "fib: RCU conversion of fib_lookup()" removed rcu_read_lock() from
__mkroute_output but left a couple of calls to rcu_read_unlock() in there.
This causes lockdep to complain that the rcu_read_unlock() call in
__ip_route_output_key causes a lock inbalance and quickly crashes the
kernel. The below fixes this for me.

Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-08 10:51:08 -07:00
Eric Dumazet ebc0ffae5d fib: RCU conversion of fib_lookup()
fib_lookup() converted to be called in RCU protected context, no
reference taken and released on a contended cache line (fib_clntref)

fib_table_lookup() and fib_semantic_match() get an additional parameter.

struct fib_info gets an rcu_head field, and is freed after an rcu grace
period.

Stress test :
(Sending 160.000.000 UDP frames on same neighbour,
IP route cache disabled, dual E5540 @2.53GHz,
32bit kernel, FIB_HASH) (about same results for FIB_TRIE)

Before patch :

real	1m31.199s
user	0m13.761s
sys	23m24.780s

After patch:

real	1m5.375s
user	0m14.997s
sys	15m50.115s

Before patch Profile :

13044.00 15.4% __ip_route_output_key vmlinux
 8438.00 10.0% dst_destroy           vmlinux
 5983.00  7.1% fib_semantic_match    vmlinux
 5410.00  6.4% fib_rules_lookup      vmlinux
 4803.00  5.7% neigh_lookup          vmlinux
 4420.00  5.2% _raw_spin_lock        vmlinux
 3883.00  4.6% rt_set_nexthop        vmlinux
 3261.00  3.9% _raw_read_lock        vmlinux
 2794.00  3.3% fib_table_lookup      vmlinux
 2374.00  2.8% neigh_resolve_output  vmlinux
 2153.00  2.5% dst_alloc             vmlinux
 1502.00  1.8% _raw_read_lock_bh     vmlinux
 1484.00  1.8% kmem_cache_alloc      vmlinux
 1407.00  1.7% eth_header            vmlinux
 1406.00  1.7% ipv4_dst_destroy      vmlinux
 1298.00  1.5% __copy_from_user_ll   vmlinux
 1174.00  1.4% dev_queue_xmit        vmlinux
 1000.00  1.2% ip_output             vmlinux

After patch Profile :

13712.00 15.8% dst_destroy             vmlinux
 8548.00  9.9% __ip_route_output_key   vmlinux
 7017.00  8.1% neigh_lookup            vmlinux
 4554.00  5.3% fib_semantic_match      vmlinux
 4067.00  4.7% _raw_read_lock          vmlinux
 3491.00  4.0% dst_alloc               vmlinux
 3186.00  3.7% neigh_resolve_output    vmlinux
 3103.00  3.6% fib_table_lookup        vmlinux
 2098.00  2.4% _raw_read_lock_bh       vmlinux
 2081.00  2.4% kmem_cache_alloc        vmlinux
 2013.00  2.3% _raw_spin_lock          vmlinux
 1763.00  2.0% __copy_from_user_ll     vmlinux
 1763.00  2.0% ip_output               vmlinux
 1761.00  2.0% ipv4_dst_destroy        vmlinux
 1631.00  1.9% eth_header              vmlinux
 1440.00  1.7% _raw_read_unlock_bh     vmlinux

Reference results, if IP route cache is enabled :

real	0m29.718s
user	0m10.845s
sys	7m37.341s

25213.00 29.5% __ip_route_output_key   vmlinux
 9011.00 10.5% dst_release             vmlinux
 4817.00  5.6% ip_push_pending_frames  vmlinux
 4232.00  5.0% ip_finish_output        vmlinux
 3940.00  4.6% udp_sendmsg             vmlinux
 3730.00  4.4% __copy_from_user_ll     vmlinux
 3716.00  4.4% ip_route_output_flow    vmlinux
 2451.00  2.9% __xfrm_lookup           vmlinux
 2221.00  2.6% ip_append_data          vmlinux
 1718.00  2.0% _raw_spin_lock_bh       vmlinux
 1655.00  1.9% __alloc_skb             vmlinux
 1572.00  1.8% sock_wfree              vmlinux
 1345.00  1.6% kfree                   vmlinux

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-05 20:39:38 -07:00
David S. Miller 21a180cda0 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/ipv4/Kconfig
	net/ipv4/tcp_timer.c
2010-10-04 11:56:38 -07:00
Eric Dumazet c7d4426a98 net: introduce DST_NOCACHE flag
While doing stress tests with IP route cache disabled, and multi queue
devices, I noticed a very high contention on one rwlock used in
neighbour code.

When many cpus are trying to send frames (possibly using a high
performance multiqueue device) to the same neighbour, they fight for the
neigh->lock rwlock in order to call neigh_hh_init(), and fight on
hh->hh_refcnt (a pair of atomic_inc/atomic_dec_and_test())

But we dont need to call neigh_hh_init() for dst that are used only
once. It costs four atomic operations at least, on two contended cache
lines, plus the high contention on neigh->lock rwlock.

Introduce a new dst flag, DST_NOCACHE, that is set when dst was not
inserted in route cache.

With the stress test bench, sending 160000000 frames on one neighbour,
results are :

Before patch:

real	2m28.406s
user	0m11.781s
sys	36m17.964s


After patch:

real	1m26.532s
user	0m12.185s
sys	20m3.903s

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-03 22:17:54 -07:00
Eric Dumazet 0197aa38df ipv4: rcu conversion in ip_route_output_slow
ip_route_output_slow() is enclosed in an rcu_read_lock() protected
section, so that no references are taken/released on device, thanks to
__ip_dev_find() & dev_get_by_index_rcu()

Tested with ip route cache disabled, and a stress test :

Before patch:

elapsed time :

real	1m38.347s
user	0m11.909s
sys	23m51.501s

Profile:

13788.00 22.7% ip_route_output_slow [kernel]
 7875.00 13.0% dst_destroy          [kernel]
 3925.00  6.5% fib_semantic_match   [kernel]
 3144.00  5.2% fib_rules_lookup     [kernel]
 3061.00  5.0% dst_alloc            [kernel]
 2276.00  3.7% rt_set_nexthop       [kernel]
 1762.00  2.9% fib_table_lookup     [kernel]
 1538.00  2.5% _raw_read_lock       [kernel]
 1358.00  2.2% ip_output            [kernel]

After patch:

real	1m28.808s
user	0m13.245s
sys	20m37.293s

10950.00 17.2% ip_route_output_slow [kernel]
10726.00 16.9% dst_destroy          [kernel]
 5170.00  8.1% fib_semantic_match   [kernel]
 3937.00  6.2% dst_alloc            [kernel]
 3635.00  5.7% rt_set_nexthop       [kernel]
 2900.00  4.6% fib_rules_lookup     [kernel]
 2240.00  3.5% fib_table_lookup     [kernel]
 1427.00  2.2% _raw_read_lock       [kernel]
 1157.00  1.8% kmem_cache_alloc     [kernel]

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-30 21:16:06 -07:00
Eric Dumazet dd28d1a0b5 ipv4: __mkroute_output() speedup
While doing stress tests with a disabled IP route cache, I found
__mkroute_output() was touching three times in_device atomic refcount.

Use RCU to touch it once to reduce cache line ping pongs.

Before patch

time to perform the test
real	1m42.009s
user	0m12.545s
sys	25m0.726s

Profile :

16109.00 26.4% ip_route_output_slow   vmlinux
 7434.00 12.2% dst_destroy            vmlinux
 3280.00  5.4% fib_rules_lookup       vmlinux
 3252.00  5.3% fib_semantic_match     vmlinux
 2622.00  4.3% fib_table_lookup       vmlinux
 2535.00  4.1% dst_alloc              vmlinux
 1750.00  2.9% _raw_read_lock         vmlinux
 1532.00  2.5% rt_set_nexthop         vmlinux

After patch

real	1m36.503s
user	0m12.977s
sys	23m25.608s

14234.00 22.4% ip_route_output_slow   vmlinux
 8717.00 13.7% dst_destroy            vmlinux
 4052.00  6.4% fib_rules_lookup       vmlinux
 3951.00  6.2% fib_semantic_match     vmlinux
 3191.00  5.0% dst_alloc              vmlinux
 1764.00  2.8% fib_table_lookup       vmlinux
 1692.00  2.7% _raw_read_lock         vmlinux
 1605.00  2.5% rt_set_nexthop         vmlinux

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-30 17:59:30 -07:00
Ulrich Weber 7e1b33e5ea ipv6: add IPv6 to neighbour table overflow warning
IPv4 and IPv6 have separate neighbour tables, so
the warning messages should be distinguishable.

[ Add a suitable message prefix on the ipv4 side as well -DaveM ]

Signed-off-by: Ulrich Weber <uweber@astaro.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-27 15:02:18 -07:00
Eric Dumazet 83180af0b0 net: fix rcu use in ip_route_output_slow
__in_dev_get_rtnl(dev_out) is called while RTNL is not held, thus
triggers a lockdep fault.

At this point, we only perform a raw test of dev_out->ip_ptr being NULL,
we dont need to make sure ip_ptr cant changed right after.

We can use rcu_dereference_raw() for this.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-26 19:04:07 -07:00
Eric Dumazet a02cec2155 net: return operator cleanup
Change "return (EXPR);" to "return EXPR;"

return is not a function, parentheses are not required.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-23 14:33:39 -07:00
David S. Miller e548833df8 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/mac80211/main.c
2010-09-09 22:27:33 -07:00
Jianzhao Wang ae2688d59b net: blackhole route should always be recalculated
Blackhole routes are used when xfrm_lookup() returns -EREMOTE (error
triggered by IKE for example), hence this kind of route is always
temporary and so we should check if a better route exists for next
packets.
Bug has been introduced by commit d11a4dc18b.

Signed-off-by: Jianzhao Wang <jianzhao.wang@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-08 14:35:43 -07:00
Eric Dumazet 49e8ab03eb net: build_ehash_secret() and rt_bind_peer() cleanups
Now cmpxchg() is available on all arches, we can use it in
build_ehash_secret() and rt_bind_peer() instead of using spinlocks.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-20 00:50:16 -07:00
Eric Dumazet 963bfeeeec net: RTA_MARK addition
Add a new rt attribute, RTA_MARK, and use it in
rt_fill_info()/inet_rtm_getroute() to support following commands :

ip route get 192.168.20.110 mark NUMBER
ip route get 192.168.20.108 from 192.168.20.110 iif eth1 mark NUMBER
ip route list cache [192.168.20.110] mark NUMBER

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-22 13:46:21 -07:00
Eric Dumazet 4bc2f18ba4 net/ipv4: EXPORT_SYMBOL cleanups
CodingStyle cleanups

EXPORT_SYMBOL should immediately follow the symbol declaration.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-12 12:57:54 -07:00
Eric Dumazet 317fe0e6c5 inetpeer: restore small inet_peer structures
Addition of rcu_head to struct inet_peer added 16bytes on 64bit arches.

Thats a bit unfortunate, since old size was exactly 64 bytes.

This can be solved, using an union between this rcu_head an four fields,
that are normally used only when a refcount is taken on inet_peer.
rcu_head is used only when refcnt=-1, right before structure freeing.

Add a inet_peer_refcheck() function to check this assertion for a while.

We can bring back SLAB_HWCACHE_ALIGN qualifier in kmem cache creation.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-16 11:55:39 -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
Eric Dumazet ed7865a47d ipv4: avoid two atomic ops in ip_rt_redirect()
in_dev_get() -> __in_dev_get_rcu() in a rcu protected function.

[ Fix build with CONFIG_IP_ROUTE_VERBOSE disabled. -DaveM ]

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-07 21:49:44 -07:00
Eric Dumazet 4736022844 ipv4: RCU changes in __mkroute_input()
Avoid two atomic ops on output device refcount

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-03 20:01:51 -07:00
Eric Dumazet 96d362202b ipv4: RCU conversion of ip_route_input_slow/ip_route_input_mc
Avoid two atomic ops on struct in_device refcount per incoming packet,
if slow path taken, (or route cache disabled)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-03 03:18:19 -07:00
Eric Dumazet b5f7e75547 ipv4: add LINUX_MIB_IPRPFILTER snmp counter
Christoph Lameter mentioned that packets could be dropped in input path
because of rp_filter settings, without any SNMP counter being
incremented. System administrator can have a hard time to track the
problem.

This patch introduces a new counter, LINUX_MIB_IPRPFILTER, incremented
each time we drop a packet because Reverse Path Filter triggers.

(We receive an IPv4 datagram on a given interface, and find the route to
send an answer would use another interface)

netstat -s | grep IPReversePathFilter
    IPReversePathFilter: 21714

Reported-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-03 03:18:19 -07:00
Eric Dumazet 27f39c73e6 net: Use __this_cpu_inc() in fast path
This patch saves 224 bytes of text on my machine.

__this_cpu_inc() generates a single instruction, using no scratch
registers :

  65 ff 04 25 a8 30 01 00      incl   %gs:0x130a8

instead of :

  48 c7 c2 80 30 01 00         mov    $0x13080,%rdx
  65 48 8b 04 25 88 ea 00 00   mov    %gs:0xea88,%rax
  83 44 10 28 01               addl   $0x1,0x28(%rax,%rdx,1)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-31 00:24:01 -07:00
Eric Dumazet 407eadd996 net: implements ip_route_input_noref()
ip_route_input() is the version returning a refcounted dst, while
ip_route_input_noref() returns a non refcounted one.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-17 17:18:51 -07:00
Eric Dumazet 7fee226ad2 net: add a noref bit on skb dst
Use low order bit of skb->_skb_dst to tell dst is not refcounted.

Change _skb_dst to _skb_refdst to make sure all uses are catched.

skb_dst() returns the dst, regardless of noref bit set or not, but
with a lockdep check to make sure a noref dst is not given if current
user is not rcu protected.

New skb_dst_set_noref() helper to set an notrefcounted dst on a skb.
(with lockdep check)

skb_dst_drop() drops a reference only if skb dst was refcounted.

skb_dst_force() helper is used to force a refcount on dst, when skb
is queued and not anymore RCU protected.

Use skb_dst_force() in __sk_add_backlog(), __dev_xmit_skb() if
!IFF_XMIT_DST_RELEASE or skb enqueued on qdisc queue, in
sock_queue_rcv_skb(), in __nf_queue().

Use skb_dst_force() in dev_requeue_skb().

Note: dst_use_noref() still dirties dst, we might transform it
later to do one dirtying per jiffies.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-17 17:18:50 -07:00
Neil Horman 3ee943728f ipv4: remove ip_rt_secret timer (v4)
A while back there was a discussion regarding the rt_secret_interval timer.
Given that we've had the ability to do emergency route cache rebuilds for awhile
now, based on a statistical analysis of the various hash chain lengths in the
cache, the use of the flush timer is somewhat redundant.  This patch removes the
rt_secret_interval sysctl, allowing us to rely solely on the statistical
analysis mechanism to determine the need for route cache flushes.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-08 01:57:52 -07:00
Eric Dumazet 0eae88f31c net: Fix various endianness glitches
Sparse can help us find endianness bugs, but we need to make some
cleanups to be able to more easily spot real bugs.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-20 19:06:52 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Pavel Emelyanov 6a2bad70d5 ipv4: Restart rt_intern_hash after emergency rebuild (v2)
The the rebuild changes the genid which in turn is used at
the hash calculation. Thus if we don't restart and go on with
inserting the rt will happen in wrong chain.

(Fixed Neil's comment about the index passed into the rt_intern_hash)

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-26 20:57:35 -07:00
Pavel Emelyanov b35ecb5d40 ipv4: Cleanup struct net dereference in rt_intern_hash
There's no need in getting it 3 times and gcc isn't smart enough
to understand this himself.

This is just a cleanup before the fix (next patch).

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-26 20:57:35 -07:00
Guenter Roeck 5e016cbf6c ipv4: Don't drop redirected route cache entry unless PTMU actually expired
TCP sessions over IPv4 can get stuck if routers between endpoints
do not fragment packets but implement PMTU instead, and we are using
those routers because of an ICMP redirect.

Setup is as follows

       MTU1    MTU2   MTU1
    A--------B------C------D

with MTU1 > MTU2. A and D are endpoints, B and C are routers. B and C
implement PMTU and drop packets larger than MTU2 (for example because
DF is set on all packets). TCP sessions are initiated between A and D.
There is packet loss between A and D, causing frequent TCP
retransmits.

After the number of retransmits on a TCP session reaches tcp_retries1,
tcp calls dst_negative_advice() prior to each retransmit. This results
in route cache entries for the peer to be deleted in
ipv4_negative_advice() if the Path MTU is set.

If the outstanding data on an affected TCP session is larger than
MTU2, packets sent from the endpoints will be dropped by B or C, and
ICMP NEEDFRAG will be returned. A and D receive NEEDFRAG messages and
update PMTU.

Before the next retransmit, tcp will again call dst_negative_advice(),
causing the route cache entry (with correct PMTU) to be deleted. The
retransmitted packet will be larger than MTU2, causing it to be
dropped again.

This sequence repeats until the TCP session aborts or is terminated.

Problem is fixed by removing redirected route cache entries in
ipv4_negative_advice() only if the PMTU is expired.

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-21 20:55:13 -07:00
Timo Teräs d11a4dc18b ipv4: check rt_genid in dst_check
Xfrm_dst keeps a reference to ipv4 rtable entries on each
cached bundle. The only way to renew xfrm_dst when the underlying
route has changed, is to implement dst_check for this. This is
what ipv6 side does too.

The problems started after 87c1e12b5e
("ipsec: Fix bogus bundle flowi") which fixed a bug causing xfrm_dst
to not get reused, until that all lookups always generated new
xfrm_dst with new route reference and path mtu worked. But after the
fix, the old routes started to get reused even after they were expired
causing pmtu to break (well it would occationally work if the rtable
gc had run recently and marked the route obsolete causing dst_check to
get called).

Signed-off-by: Timo Teras <timo.teras@iki.fi>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-19 21:00:41 -07:00
Vitaliy Gusev 858a18a6a2 route: Fix caught BUG_ON during rt_secret_rebuild_oneshot()
route: Fix caught BUG_ON during rt_secret_rebuild_oneshot()

Call rt_secret_rebuild can cause BUG_ON(timer_pending(&net->ipv4.rt_secret_timer)) in
add_timer as there is not any synchronization for call rt_secret_rebuild_oneshot()
for the same net namespace.

Also this issue affects to rt_secret_reschedule().

Thus use mod_timer enstead.

Signed-off-by: Vitaliy Gusev <vgusev@openvz.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-16 14:15:47 -07:00
Eric Dumazet 9837638727 net: fix route cache rebuilds
We added an automatic route cache rebuilding in commit 1080d709fb
but had to correct few bugs. One of the assumption of original patch,
was that entries where kept sorted in a given way.

This assumption is known to be wrong (commit 1ddbcb005c gave an
explanation of this and corrected a leak) and expensive to respect.

Paweł Staszewski reported to me one of his machine got its routing cache
disabled after few messages like :

[ 2677.850065] Route hash chain too long!
[ 2677.850080] Adjust your secret_interval!
[82839.662993] Route hash chain too long!
[82839.662996] Adjust your secret_interval!
[155843.731650] Route hash chain too long!
[155843.731664] Adjust your secret_interval!
[155843.811881] Route hash chain too long!
[155843.811891] Adjust your secret_interval!
[155843.858209] vlan0811: 5 rebuilds is over limit, route caching
disabled
[155843.858212] Route hash chain too long!
[155843.858213] Adjust your secret_interval!

This is because rt_intern_hash() might be fooled when computing a chain
length, because multiple entries with same keys can differ because of
TOS (or mark/oif) bits.

In the rare case the fast algorithm see a too long chain, and before
taking expensive path, we call a helper function in order to not count
duplicates of same routes, that only differ with tos/mark/oif bits. This
helper works with data already in cpu cache and is not be very
expensive, despite its O(N^2) implementation.

Paweł Staszewski sucessfully tested this patch on his loaded router.

Reported-and-tested-by: Paweł Staszewski <pstaszewski@itcare.pl>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-08 10:45:31 -08:00