Commit Graph

17801 Commits

Author SHA1 Message Date
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
Johannes Berg
207aba6018 mac80211: support IBSS RSN with SW crypto
When software crypto is used, mac80211 will
support IBSS RSN, it doesn't depend on the
driver in that case.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-13 15:23:30 -05:00
Tim Harvey
91f44b0299 mac80211 default tx_last_beacon false (congestion)
The 802.11 spec states that the STA that generated the last Beacon frame shall
be the STA that response to a probe request.  This is important for congestion
reduction when a probe request is received - only 1 node in an adhoc BSS
will transmit a response.  While mac80211 drivers should provide the
tx_last_beacon function to report if they transmitted the last beacon many
do not.  As an attempt to reduce probe response congestion default this
to 0 such that a node not implementing this capability does not contribute
to unnecessary congestion.

In a modern medium sized office environment I see upwards of 100 probe
requests per second received at a given node from various hardware/OS/drivers
doing zeroconf 'active probing' as opposed to passively listening for beacons.
With a modest 10-node adhoc network consisting of drivers that do not implement
this tx_last_beacon feature, I have seen this result in the simultaneous xmit
of probe responses accumulating to 500 probe responses per second because of
collisions which brings the adhoc network to its knees as well as causes
needless congestion.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-13 15:23:29 -05:00
Johannes Berg
f7e0104c1a mac80211: support separate default keys
Add support for split default keys (unicast
and multicast) in mac80211.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-13 15:23:29 -05:00
Johannes Berg
dbd2fd656f cfg80211/nl80211: separate unicast/multicast default TX keys
Allow userspace to specify that a given key
is default only for unicast and/or multicast
transmissions. Only WEP keys are for both,
WPA/RSN keys set here are GTKs for multicast
only. For more future flexibility, allow to
specify all combiations.

Wireless extensions can only set both so use
nl80211; WEP keys (connect keys) must be set
as default for both (but 802.1X WEP is still
possible).

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-13 15:23:28 -05:00
Johannes Berg
897bed8b43 mac80211: clean up RX key checks
Using the default key for "any key set" isn't
quite what we should do. It works, but with the
upcoming changes it makes life unnecessarily
complex, so do something better here and really
check for "any key".

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-13 15:23:28 -05:00
Sven Neumann
01123e2331 cfg80211: update information elements in cached BSS struct
When a cached BSS struct is updated because a new beacon was received,
the code replaces the cached information elements by the IEs from the
new beacon. However it did not update the pub.information_elements
and pub.len_information_elements fields leaving them either pointing
to the old beacon IEs or in an inconsistent state where the data is
replaced by the new beacon IEs but len_information_elements still has
its value from the first beacon.

Fix this by updating the information elements fields if they are
pointing to beacon IEs.

Signed-off-by: Sven Neumann <s.neumann@raumfeld.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-13 15:23:28 -05:00
Bruno Randolf
a7ffac9591 cfg80211: Add antenna availability information
Add a field to wiphy for the hardware to report the availble antennas for
configuration. Only if this is set to something bigger than zero, will the
anntenna configuration ops be executed.

Allthough this could be a simple number of antennas, I defined it as a bitmap
of antennas which are available for configuration, since it's more consistent
with the rest of the antenna API and there could be cases where the
hardware allows only configuration of certain antennas. As it does not make
much of a difference in size or normal usage, I think it's better to be able to
support this, in case the need arises.

The antenna configuration is now also checked against the availabe antennas and
rejected if it does not match.

Signed-off-by: Bruno Randolf <br1@einfach.org>

--
v3:	always apply available antenna mask (for "all" antennas case).

v2:	reject antenna configurations which don't match the available antennas
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-13 15:23:27 -05:00
John W. Linville
1d212aa96e Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem 2010-12-13 15:20:45 -05:00
Eric Dumazet
249fab773d net: add limits to ip_default_ttl
ip_default_ttl should be between 1 and 255

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-13 12:16:14 -08:00
Herton Ronaldo Krzesinski
8808f64171 mac80211: avoid calling ieee80211_work_work unconditionally
On suspend, there might be usb wireless drivers which wrongly trigger
the warning in ieee80211_work_work. If an usb driver doesn't have a
suspend hook, the usb stack will disconnect the device. On disconnect,
a mac80211 driver calls ieee80211_unregister_hw, which calls dev_close,
which calls ieee80211_stop, and in the end calls ieee80211_work_purge->
ieee80211_work_work.

The problem is that this call to ieee80211_work_purge comes after
mac80211 is suspended, triggering the warning even when we don't have
work queued in work_list (the expected case when already suspended),
because it always calls ieee80211_work_work.

So, just call ieee80211_work_work in ieee80211_work_purge if we really
have to abort work. This addresses the warning reported at
https://bugzilla.kernel.org/show_bug.cgi?id=24402

Signed-off-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-13 14:55:08 -05:00
Tim Harvey
c926d006c1 mac80211: Fix NULL-pointer deference on ibss merge when not ready
dev_open will eventually call ieee80211_ibss_join which sets up the
skb used for beacons/probe-responses however it is possible to
receive beacons that attempt to merge before this occurs causing
a null pointer dereference.  Check ssid_len as that is the last
thing set in ieee80211_ibss_join.

This occurs quite easily in the presence of adhoc nodes with hidden SSID's

revised previous patch to check further up based on irc feedback

Signed-off-by: Tim Harvey <harvey.tim@gmail.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-13 14:53:46 -05:00
John W. Linville
10c38c3306 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/padovan/bluetooth-2.6 2010-12-13 14:41:23 -05:00
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
a02e4b7dae ipv6: Demark default hoplimit as zero.
This is for consistency with ipv4.  Using "-1" makes
no sense.

It was made this way a long time ago merely to be consistent
with how the ipv6 socket hoplimit "default" is stored.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-12 21:39:02 -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
abbf46ae0e ipv6: Use ip6_dst_hoplimit() instead of direct dst_metric() calls.
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-12 21:14:46 -08:00
Eric Dumazet
a19faf0250 net: fix skb_defer_rx_timestamp()
After commit c1f19b51d1 (net: support time stamping in phy devices.),
kernel might crash if CONFIG_NETWORK_PHY_TIMESTAMPING=y and
skb_defer_rx_timestamp() handles a packet without an ethernet header.

Fixes kernel bugzilla #24102

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=24102
Reported-and-tested-by: Andrew Watts <akwatts@ymail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 16:20:56 -08:00
Herbert Xu
deef4b522b bridge: Use consistent NF_DROP returns in nf_pre_routing
The nf_pre_routing functions in bridging have collected two
distinct ways of returning NF_DROP over the years, inline and
via goto.  There is no reason for preferring either one.

So this patch arbitrarily picks the inline variant and converts
the all the gotos.

Also removes a redundant comment.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 16:04:53 -08:00
Changli Gao
c053fd96d0 af_packet: use swap() instead of the open coded macro XC()
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 16:02:20 -08:00
Ben Hutchings
e596e6e4d5 ethtool: Report link-down while interface is down
While an interface is down, many implementations of
ethtool_ops::get_link, including the default, ethtool_op_get_link(),
will report the last link state seen while the interface was up.  In
general the current physical link state is not available if the
interface is down.

Define ETHTOOL_GLINK to reflect whether the interface *and* any
physical port have a working link, and consistently return 0 when the
interface is down.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 15:55:23 -08:00
Dan Williams
d9ca676bcb atm: correct sysfs 'device' link creation and parent relationships
The ATM subsystem was incorrectly creating the 'device' link for ATM
nodes in sysfs.  This led to incorrect device/parent relationships
exposed by sysfs and udev.  Instead of rolling the 'device' link by hand
in the generic ATM code, pass each ATM driver's bus device down to the
sysfs code and let sysfs do this stuff correctly.

Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 15:45:05 -08:00
Junchang Wang
a8d764b983 pktgen: adding prefetchw() call
We know for sure pktgen is going to write skb->data right after
*_alloc_skb, causing unnecessary cache misses.

Idea is to add a prefetchw() call to prefetch the first cache line
indicated by skb->data. On systems with Adjacent Cache Line Prefetch,
it's probably two cache lines are prefetched.

With this patch, pktgen on Intel SR1625 server with two E5530
quad-core processors and a single ixgbe-based NIC went from 8.63Mpps
to 9.03Mpps, with 4.6% improvement.

Signed-off-by: Junchang Wang <junchangwang@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 15:36:52 -08:00
Wei Yongjun
40a010395c SCTP: Fix SCTP_SET_PEER_PRIMARY_ADDR to accpet v4mapped address
SCTP_SET_PEER_PRIMARY_ADDR does not accpet v4mapped address, using
v4mapped address in SCTP_SET_PEER_PRIMARY_ADDR socket option will
get -EADDRNOTAVAIL error if v4map is enabled. This patch try to
fix it by mapping v4mapped address to v4 address if allowed.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 15:29:49 -08:00
Tobias Klauser
376d940ee9 inet6: Remove redundant unlikely()
IS_ERR() already implies unlikely(), so it can be omitted here.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 14:57:34 -08:00
Martin Willi
040253c931 xfrm: Traffic Flow Confidentiality for IPv6 ESP
Add TFC padding to all packets smaller than the boundary configured
on the xfrm state. If the boundary is larger than the PMTU, limit
padding to the PMTU.

Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 14:43:59 -08:00
Martin Willi
d979e20f2b xfrm: Traffic Flow Confidentiality for IPv4 ESP
Add TFC padding to all packets smaller than the boundary configured
on the xfrm state. If the boundary is larger than the PMTU, limit
padding to the PMTU.

Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 14:43:59 -08:00
Martin Willi
35d2856b46 xfrm: Add Traffic Flow Confidentiality padding XFRM attribute
The XFRMA_TFCPAD attribute for XFRM state installation configures
Traffic Flow Confidentiality by padding ESP packets to a specified
length.

Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 14:43:58 -08:00
Jiri Pirko
c07224005d net/ipv6/udp.c: fix typo in flush_stack()
skb1 should be passed as parameter to sk_rcvqueues_full() here.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 14:05:09 -08:00
David S. Miller
457de4383e ipv6: Fix 'release_it' logic in tcp_v6_get_peer()
We accidently set it to "true" for the case where we
are using a route bound peer.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 13:16:09 -08:00
Tobias Klauser
4c0833bcd4 bridge: Fix return values of br_multicast_add_group/br_multicast_new_group
If br_multicast_new_group returns NULL, we would return 0 (no error) to
the caller of br_multicast_add_group, which is not what we want. Instead
br_multicast_new_group should return ERR_PTR(-ENOMEM) in this case.
Also propagate the error number returned by br_mdb_rehash properly.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 13:00:39 -08:00
David S. Miller
e91db5cd6f Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 2010-12-10 12:51:02 -08:00
Nicolas Dichtel
5f75a1042f ipv6: fix nl group when advertising a new link
New idev are advertised with NL group RTNLGRP_IPV6_IFADDR, but
should use RTNLGRP_IPV6_IFINFO.
Bug was introduced by commit 8d7a76c9.

Signed-off-by: Wang Xuefu <xuefu.wang@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 12:49:36 -08:00
David S. Miller
eaa7dcde1d Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/net-next-2.6 2010-12-10 11:22:57 -08:00
Martin Lucina
c1249c0aae net: Document the kernel_recvmsg() function
Signed-off-by: Martin Lucina <mato@kotelna.sk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10 11:13:18 -08:00
David S. Miller
1e13f863ca Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6
Conflicts:
	drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
2010-12-10 09:50:47 -08:00
Uwe Kleine-König
a34f0b3139 fix comment typos concerning "consistent"
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-12-10 16:04:28 +01:00
Shan Wei
b7ec19af63 dccp: remove unused macros
Remove macros which have been unused since the initial implementation
(commit 7c657876b6, [DCCP]: Initial
 implementation from Tue Aug 9 20:14:34 2005 -0700).

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-12-10 12:49:23 +01:00
Eric Dumazet
4bc65dd8d8 filter: use size of fetched data in __load_pointer()
__load_pointer() checks data we fetch from skb is included in head
portion, but assumes we fetch one byte, instead of up to four.

This wont crash because we have extra bytes (struct skb_shared_info)
after head, but this can read uninitialized bytes.

Fix this using size of the data (1, 2, 4 bytes) in the test.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09 20:47:04 -08:00
Thomas Egerer
78347c8c6b xfrm: Fix xfrm_state_migrate leak
xfrm_state_migrate calls kfree instead of xfrm_state_put to free
a failed state. According to git commit 553f9118 this can cause
memory leaks.

Signed-off-by: Thomas Egerer <thomas.egerer@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09 20:35:27 -08:00
Eric Dumazet
68835aba4d net: optimize INET input path further
Followup of commit b178bb3dfc (net: reorder struct sock fields)

Optimize INET input path a bit further, by :

1) moving sk_refcnt close to sk_lock.

This reduces number of dirtied cache lines by one on 64bit arches (and
64 bytes cache line size).

2) moving inet_daddr & inet_rcv_saddr at the beginning of sk

(same cache line than hash / family / bound_dev_if / nulls_node)

This reduces number of accessed cache lines in lookups by one, and dont
increase size of inet and timewait socks.
inet and tw sockets now share same place-holder for these fields.

Before patch :

offsetof(struct sock, sk_refcnt) = 0x10
offsetof(struct sock, sk_lock) = 0x40
offsetof(struct sock, sk_receive_queue) = 0x60
offsetof(struct inet_sock, inet_daddr) = 0x270
offsetof(struct inet_sock, inet_rcv_saddr) = 0x274

After patch :

offsetof(struct sock, sk_refcnt) = 0x44
offsetof(struct sock, sk_lock) = 0x48
offsetof(struct sock, sk_receive_queue) = 0x68
offsetof(struct inet_sock, inet_daddr) = 0x0
offsetof(struct inet_sock, inet_rcv_saddr) = 0x4

compute_score() (udp or tcp) now use a single cache line per ignored
item, instead of two.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09 20:05:58 -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
4e085e76cb econet: Fix crash in aun_incoming().
Unconditional use of skb->dev won't work here,
try to fetch the econet device via skb_dst()->dev
instead.

Suggested by Eric Dumazet.

Reported-by: Nelson Elhage <nelhage@ksplice.com>
Tested-by: Nelson Elhage <nelhage@ksplice.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 20:51:15 -08:00
David S. Miller
fe6c791570 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
	net/llc/af_llc.c
2010-12-08 13:47:38 -08:00
John W. Linville
393934c6b5 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6
Conflicts:
	drivers/net/wireless/ath/ath9k/ath9k.h
	drivers/net/wireless/ath/ath9k/main.c
	drivers/net/wireless/ath/ath9k/xmit.c
2010-12-08 16:23:31 -05:00
Ben Greear
2f88675011 mac80211: Show max number of probe tries in debug message.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-08 15:38:44 -05:00
Helmut Schaa
80d7e403c9 mac80211: Apply ht_opmode changes in ieee80211_change_bss
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-08 15:38:43 -05:00
Helmut Schaa
50b12f597b cfg80211: Add new BSS attribute ht_opmode
Add a new BSS attribute to allow hostapd to set the current HT opmode.
Otherwise drivers won't be able to set up protection for HT rates in
AP mode.

Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-08 15:38:43 -05:00
Eric Dumazet
f19872575f tcp: protect sysctl_tcp_cookie_size reads
Make sure sysctl_tcp_cookie_size is read once in
tcp_cookie_size_check(), or we might return an illegal value to caller
if sysctl_tcp_cookie_size is changed by another cpu.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: William Allen Simpson <william.allen.simpson@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 12:34:09 -08:00
Eric Dumazet
ad9f4f50fe tcp: avoid a possible divide by zero
sysctl_tcp_tso_win_divisor might be set to zero while one cpu runs in
tcp_tso_should_defer(). Make sure we dont allow a divide by zero by
reading sysctl_tcp_tso_win_divisor exactly once.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 12:34:08 -08:00