Commit Graph

1725 Commits

Author SHA1 Message Date
Alexey Dobriyan
59c9940ed0 netns xfrm: per-netns MIBs
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 17:59:52 -08:00
Alexey Dobriyan
4fb236bac9 netns xfrm: AH/ESP in netns!
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 17:59:27 -08:00
Alexey Dobriyan
fbda33b2b8 netns xfrm: ->get_saddr in netns
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 17:56:49 -08:00
Alexey Dobriyan
c5b3cf46ea netns xfrm: ->dst_lookup in netns
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 17:51:25 -08:00
Alexey Dobriyan
db983c1144 netns xfrm: KM reporting in netns
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 17:51:01 -08:00
Alexey Dobriyan
ddcfd79680 netns xfrm: dst garbage-collecting in netns
Pass netns pointer to struct xfrm_policy_afinfo::garbage_collect()

	[This needs more thoughts on what to do with dst_ops]
	[Currently stub to init_net]

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 17:37:23 -08:00
Alexey Dobriyan
52479b623d netns xfrm: lookup in netns
Pass netns to xfrm_lookup()/__xfrm_lookup(). For that pass netns
to flow_cache_lookup() and resolver callback.

Take it from socket or netdevice. Stub DECnet to init_net.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 17:35:18 -08:00
Alexey Dobriyan
221df1ed33 netns xfrm: state lookup in netns
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 17:30:50 -08:00
Alexey Dobriyan
673c09be45 netns xfrm: add struct xfrm_state::xs_net
To avoid unnecessary complications with passing netns around.

* set once, very early after allocating
* once set, never changes

For a while create every xfrm_state in init_net.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 17:15:16 -08:00
Ingo Molnar
55205d400e ipv6: fix warning in net/ipv6/ip6_flowlabel.c
this warning:

  net/ipv6/ip6_flowlabel.c: In function ‘ipv6_flowlabel_opt’:
  net/ipv6/ip6_flowlabel.c:467: warning: ‘err’ may be used uninitialized in this function

triggers because GCC does not recognize the (correct) error flow
between fl_create() and 'err'.

Annotate it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 16:50:30 -08:00
Alexey Dobriyan
fb7e06748c xfrm: remove useless forward declarations
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 01:05:54 -08:00
Alexey Dobriyan
6daad37230 ah4/ah6: remove useless NULL assignments
struct will be kfreed in a moment, so...

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 01:05:09 -08:00
Alexey Dobriyan
be77e59307 net: fix tunnels in netns after ndo_ changes
dev_net_set() should be the very first thing after alloc_netdev().

"ndo_" changes turned simple assignment (which is OK to do before netns
assignment) into quite non-trivial operation (which is not OK, init_net was
used). This leads to incomplete initialisation of tunnel device in netns.

BUG: unable to handle kernel NULL pointer dereference at 00000004
IP: [<c02efdb5>] ip6_tnl_exit_net+0x37/0x4f
*pde = 00000000 
Oops: 0000 [#1] PREEMPT DEBUG_PAGEALLOC
last sysfs file: /sys/class/net/lo/operstate

Pid: 10, comm: netns Not tainted (2.6.28-rc6 #1) 
EIP: 0060:[<c02efdb5>] EFLAGS: 00010246 CPU: 0
EIP is at ip6_tnl_exit_net+0x37/0x4f
EAX: 00000000 EBX: 00000020 ECX: 00000000 EDX: 00000003
ESI: c5caef30 EDI: c782bbe8 EBP: c7909f50 ESP: c7909f48
 DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
Process netns (pid: 10, ti=c7908000 task=c7905780 task.ti=c7908000)
Stack:
 c03e75e0 c7390bc8 c7909f60 c0245448 c7390bd8 c7390bf0 c7909fa8 c012577a
 00000000 00000002 00000000 c0125736 c782bbe8 c7909f90 c0308fe3 c782bc04
 c7390bd4 c0245406 c084b718 c04f0770 c03ad785 c782bbe8 c782bc04 c782bc0c
Call Trace:
 [<c0245448>] ? cleanup_net+0x42/0x82
 [<c012577a>] ? run_workqueue+0xd6/0x1ae
 [<c0125736>] ? run_workqueue+0x92/0x1ae
 [<c0308fe3>] ? schedule+0x275/0x285
 [<c0245406>] ? cleanup_net+0x0/0x82
 [<c0125ae1>] ? worker_thread+0x81/0x8d
 [<c0128344>] ? autoremove_wake_function+0x0/0x33
 [<c0125a60>] ? worker_thread+0x0/0x8d
 [<c012815c>] ? kthread+0x39/0x5e
 [<c0128123>] ? kthread+0x0/0x5e
 [<c0103b9f>] ? kernel_thread_helper+0x7/0x10
Code: db e8 05 ff ff ff 89 c6 e8 dc 04 f6 ff eb 08 8b 40 04 e8 38 89 f5 ff 8b 44 9e 04 85 c0 75 f0 43 83 fb 20 75 f2 8b 86 84 00 00 00 <8b> 40 04 e8 1c 89 f5 ff e8 98 04 f6 ff 89 f0 e8 f8 63 e6 ff 5b 
EIP: [<c02efdb5>] ip6_tnl_exit_net+0x37/0x4f SS:ESP 0068:c7909f48
---[ end trace 6c2f2328fccd3e0c ]---

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-23 17:26:26 -08:00
Eric Dumazet
c25eb3bfb9 net: Convert TCP/DCCP listening hash tables to use RCU
This is the last step to be able to perform full RCU lookups
in __inet_lookup() : After established/timewait tables, we
add RCU lookups to listening hash table.

The only trick here is that a socket of a given type (TCP ipv4,
TCP ipv6, ...) can now flight between two different tables
(established and listening) during a RCU grace period, so we
must use different 'nulls' end-of-chain values for two tables.

We define a large value :

#define LISTENING_NULLS_BASE (1U << 29)

So that slots in listening table are guaranteed to have different
end-of-chain values than slots in established table. A reader can
still detect it finished its lookup in the right chain.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-23 17:22:55 -08:00
Qinghuang Feng
cf005b1d0e net: remove redundant argument comments
Remove redundant argument comments in files of net/*

Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-21 17:15:03 -08:00
Eric Dumazet
9db66bdcc8 net: convert TCP/DCCP ehash rwlocks to spinlocks
Now TCP & DCCP use RCU lookups, we can convert ehash rwlocks to spinlocks.

/proc/net/tcp and other seq_file 'readers' can safely be converted to 'writers'.

This should speedup writers, since spin_lock()/spin_unlock()
only use one atomic operation instead of two for write_lock()/write_unlock()

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20 20:39:09 -08:00
Stephen Hemminger
1326c3d5a4 ipv6: convert tunnels to net_device_ops
Like IPV4, convert the tunnel virtual devices to use net_device_ops.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20 20:33:56 -08:00
Stephen Hemminger
007c3838d9 ipmr: convert ipmr virtual interface to net_device_ops
Convert to new network device ops interface.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20 20:28:35 -08:00
David S. Miller
6ab33d5171 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/ixgbe/ixgbe_main.c
	include/net/mac80211.h
	net/phonet/af_phonet.c
2008-11-20 16:44:00 -08:00
Alexey Dobriyan
5ece6c2ddd net: fix tiny output corruption of /proc/net/snmp6
Because "name" is static, it can be occasionally be filled with
somewhat garbage if two processes read /proc/net/snmp6.

Also, remove useless casts and "-1" -- snprintf() correctly terminates it's
output.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20 04:20:10 -08:00
Benjamin Thery
eedd726efb ipv6: use seq_release_private for ip6mr.c /proc entries
In ip6mr.c, /proc entries /proc/net/ip6_mr_cache and /proc/net/ip6_mr_vif
are opened with seq_open_private(), thus seq_release_private() should be 
used to release them.
Should fix a small memory leak.

Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20 04:16:12 -08:00
Eric Dumazet
5caea4ea70 net: listening_hash get a spinlock per bucket
This patch prepares RCU migration of listening_hash table for
TCP/DCCP protocols.

listening_hash table being small (32 slots per protocol), we add
a spinlock for each slot, instead of a single rwlock for whole table.

This should reduce hold time of readers, and writers concurrency.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20 00:40:07 -08:00
Stephen Hemminger
5bc3eb7e2f ip: convert to net_device_ops for ioctl
Convert to net_device_ops function table pointer for ioctl.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-19 22:42:41 -08:00
Joe Perches
07f0757a68 include/net net/ - csum_partial - remove unnecessary casts
The first argument to csum_partial is const void *
casts to char/u8 * are not necessary

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-19 15:44:53 -08:00
David S. Miller
198d6ba4d7 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/isdn/i4l/isdn_net.c
	fs/cifs/connect.c
2008-11-18 23:38:23 -08:00
Eric Dumazet
3ab5aee7fe net: Convert TCP & DCCP hash tables to use RCU / hlist_nulls
RCU was added to UDP lookups, using a fast infrastructure :
- sockets kmem_cache use SLAB_DESTROY_BY_RCU and dont pay the
  price of call_rcu() at freeing time.
- hlist_nulls permits to use few memory barriers.

This patch uses same infrastructure for TCP/DCCP established
and timewait sockets.

Thanks to SLAB_DESTROY_BY_RCU, no slowdown for applications
using short lived TCP connections. A followup patch, converting
rwlocks to spinlocks will even speedup this case.

__inet_lookup_established() is pretty fast now we dont have to
dirty a contended cache line (read_lock/read_unlock)

Only established and timewait hashtable are converted to RCU
(bind table and listen table are still using traditional locking)

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-16 19:40:17 -08:00
Eric Dumazet
88ab1932ea udp: Use hlist_nulls in UDP RCU code
This is a straightforward patch, using hlist_nulls infrastructure.

RCUification already done on UDP two weeks ago.

Using hlist_nulls permits us to avoid some memory barriers, both
at lookup time and delete time.

Patch is large because it adds new macros to include/net/sock.h.
These macros will be used by TCP & DCCP in next patch.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-16 19:39:21 -08:00
Brian Haley
6e093d9dff ipv6: routing header fixes
This patch fixes two bugs:

1. setsockopt() of anything but a Type 2 routing header should return
EINVAL instead of EPERM.  Noticed by Shan Wei
(shanwei@cn.fujitsu.com).

2. setsockopt()/sendmsg() of a Type 2 routing header with invalid
length or segments should return EINVAL.  These values are statically
fixed in RFC 3775, unlike the variable Type 0 was.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-12 22:59:21 -08:00
Alexey Dobriyan
6bb3ce25d0 net: remove struct dst_entry::entry_size
Unused after kmem_cache_zalloc() conversion.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-11 17:25:22 -08:00
David S. Miller
7e452baf6b Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/message/fusion/mptlan.c
	drivers/net/sfc/ethtool.c
	net/mac80211/debugfs_sta.c
2008-11-11 15:43:02 -08:00
Benjamin Thery
87b30a6530 ipv6: fix ip6_mr_init error path
The order of cleanup operations in the error/exit section of ip6_mr_init()
is completely inversed. It should be the other way around.
Also a del_timer() is missing in the error path.

Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-10 16:34:11 -08:00
David S. Miller
167c6274c3 Merge branch 'davem-next' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6 2008-11-07 01:37:16 -08:00
David S. Miller
9eeda9abd1 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/wireless/ath5k/base.c
	net/8021q/vlan_core.c
2008-11-06 22:43:03 -08:00
Brian Haley
305d552acc bonding: send IPv6 neighbor advertisement on failover
This patch adds better IPv6 failover support for bonding devices,
especially when in active-backup mode and there are only IPv6 addresses
configured, as reported by Alex Sidorenko.

- Creates a new file, net/drivers/bonding/bond_ipv6.c, for the
   IPv6-specific routines.  Both regular bonds and VLANs over bonds
   are supported.

- Adds a new tunable, num_unsol_na, to limit the number of unsolicited
   IPv6 Neighbor Advertisements that are sent on a failover event.
   Default is 1.

- Creates two new IPv6 neighbor discovery functions:

   ndisc_build_skb()
   ndisc_send_skb()

   These were required to support VLANs since we have to be able to
   add the VLAN id to the skb since ndisc_send_na() and friends
   shouldn't be asked to do this.  These two routines are basically
   __ndisc_send() split into two pieces, in a slightly different order.

- Updates Documentation/networking/bonding.txt and bumps the rev of bond
   support to 3.4.0.

On failover, this new code will generate one packet:

- An unsolicited IPv6 Neighbor Advertisement, which helps the switch
   learn that the address has moved to the new slave.

Testing has shown that sending just the NA results in pretty good
behavior when in active-back mode, I saw no lost ping packets for example.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-11-06 00:49:37 -05:00
Benjamin Thery
e3ec6cfc26 ipv6: fix run pending DAD when interface becomes ready
With some net devices types, an IPv6 address configured while the
interface was down can stay 'tentative' forever, even after the interface
is set up. In some case, pending IPv6 DADs are not executed when the
device becomes ready.

I observed this while doing some tests with kvm. If I assign an IPv6 
address to my interface eth0 (kvm driver rtl8139) when it is still down
then the address is flagged tentative (IFA_F_TENTATIVE). Then, I set
eth0 up, and to my surprise, the address stays 'tentative', no DAD is
executed and the address can't be pinged.

I also observed the same behaviour, without kvm, with virtual interfaces
types macvlan and veth.

Some easy steps to reproduce the issue with macvlan:

1. ip link add link eth0 type macvlan
2. ip -6 addr add 2003::ab32/64 dev macvlan0
3. ip addr show dev macvlan0
   ... 
   inet6 2003::ab32/64 scope global tentative
   ...
4. ip link set macvlan0 up
5. ip addr show dev macvlan0
   ...
   inet6 2003::ab32/64 scope global tentative
   ...
   Address is still tentative

I think there's a bug in net/ipv6/addrconf.c, addrconf_notify():
addrconf_dad_run() is not always run when the interface is flagged IF_READY.
Currently it is only run when receiving NETDEV_CHANGE event. Looks like
some (virtual) devices doesn't send this event when becoming up.

For both NETDEV_UP and NETDEV_CHANGE events, when the interface becomes
ready, run_pending should be set to 1. Patch below.

'run_pending = 1' could be moved below the if/else block but it makes 
the code less readable.

Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-05 01:43:57 -08:00
Andreas Steffen
79654a7698 xfrm: Have af-specific init_tempsel() initialize family field of temporary selector
While adding MIGRATE support to strongSwan, Andreas Steffen noticed that
the selectors provided in XFRM_MSG_ACQUIRE have their family field
uninitialized (those in MIGRATE do have their family set).

Looking at the code, this is because the af-specific init_tempsel()
(called via afinfo->init_tempsel() in xfrm_init_tempsel()) do not set
the value.

Reported-by: Andreas Steffen <andreas.steffen@strongswan.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
2008-11-04 14:49:19 -08:00
Alexey Dobriyan
6d9f239a1e net: '&' redux
I want to compile out proc_* and sysctl_* handlers totally and
stub them to NULL depending on config options, however usage of &
will prevent this, since taking adress of NULL pointer will break
compilation.

So, drop & in front of every ->proc_handler and every ->strategy
handler, it was never needed in fact.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-03 18:21:05 -08:00
Wei Yongjun
0856f93958 udp: Fix the SNMP counter of UDP_MIB_INERRORS
UDP packets received in udpv6_recvmsg() are not only IPv6 UDP packets, but
also have IPv4 UDP packets, so when do the counter of UDP_MIB_INERRORS in
udpv6_recvmsg(), we should check whether the packet is a IPv6 UDP packet
or a IPv4 UDP packet.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-02 23:52:46 -08:00
Wei Yongjun
f26ba17511 udp: Fix the SNMP counter of UDP_MIB_INDATAGRAMS
If UDP echo is sent to xinetd/echo-dgram, the UDP reply will be received
at the sender. But the SNMP counter of UDP_MIB_INDATAGRAMS will be not
increased, UDP6_MIB_INDATAGRAMS will be increased instead.

  Endpoint A                      Endpoint B
  UDP Echo request ----------->
  (IPv4, Dst port=7)
                   <----------    UDP Echo Reply
                                  (IPv4, Src port=7)

This bug is come from this patch cb75994ec3.

It do counter UDP[6]_MIB_INDATAGRAMS until udp[v6]_recvmsg. Because
xinetd used IPv6 socket to receive UDP messages, thus, when received
UDP packet, the UDP6_MIB_INDATAGRAMS will be increased in function
udpv6_recvmsg() even if the packet is a IPv4 UDP packet.

This patch fixed the problem.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-02 23:52:45 -08:00
Eric Dumazet
920a46115c udp: multicast packets need to check namespace
Current UDP multicast delivery is not namespace aware.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-01 21:22:23 -07:00
Nicolas Dichtel
7e3a42a12c xfrm6: handling fragment
RFC4301 Section 7.1 says:

"7.1.  Tunnel Mode SAs that Carry Initial and Non-Initial Fragments

     All implementations MUST support tunnel mode SAs that are configured
     to pass traffic without regard to port field (or ICMP type/code or
     Mobility Header type) values.  If the SA will carry traffic for
     specified protocols, the selector set for the SA MUST specify the
     port fields (or ICMP type/code or Mobility Header type) as ANY.  An
     SA defined in this fashion will carry all traffic including initial
     and non-initial fragments for the indicated Local/Remote addresses
     and specified Next Layer protocol(s)."

But for IPv6, fragment is treated as a protocol.  This change catches
protocol transported in fragmented packet.  In IPv4, there is no
problem.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-01 21:12:07 -07:00
Harvey Harrison
673d57e723 net: replace NIPQUAD() in net/ipv4/ net/ipv6/
Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u
can be replaced with %pI4

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-31 00:53:57 -07:00
Harvey Harrison
5b095d9892 net: replace %p6 with %pI6
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29 12:52:50 -07:00
Harvey Harrison
4b7a4274ca net: replace %#p6 format specifier with %pi6
gcc warns when using the # modifier with the %p format specifier,
so we can't use this to omit the colons when needed, introduces
%pi6 instead.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29 12:50:24 -07:00
Eric Dumazet
96631ed16c udp: introduce sk_for_each_rcu_safenext()
Corey Minyard found a race added in commit 271b72c7fa
(udp: RCU handling for Unicast packets.)

 "If the socket is moved from one list to another list in-between the
 time the hash is calculated and the next field is accessed, and the
 socket has moved to the end of the new list, the traversal will not
 complete properly on the list it should have, since the socket will
 be on the end of the new list and there's not a way to tell it's on a
 new list and restart the list traversal.  I think that this can be
 solved by pre-fetching the "next" field (with proper barriers) before
 checking the hash."

This patch corrects this problem, introducing a new
sk_for_each_rcu_safenext() macro.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29 11:19:58 -07:00
Eric Dumazet
271b72c7fa udp: RCU handling for Unicast packets.
Goals are :

1) Optimizing handling of incoming Unicast UDP frames, so that no memory
 writes should happen in the fast path.

 Note: Multicasts and broadcasts still will need to take a lock,
 because doing a full lockless lookup in this case is difficult.

2) No expensive operations in the socket bind/unhash phases :
  - No expensive synchronize_rcu() calls.

  - No added rcu_head in socket structure, increasing memory needs,
  but more important, forcing us to use call_rcu() calls,
  that have the bad property of making sockets structure cold.
  (rcu grace period between socket freeing and its potential reuse
   make this socket being cold in CPU cache).
  David did a previous patch using call_rcu() and noticed a 20%
  impact on TCP connection rates.
  Quoting Cristopher Lameter :
   "Right. That results in cacheline cooldown. You'd want to recycle
    the object as they are cache hot on a per cpu basis. That is screwed
    up by the delayed regular rcu processing. We have seen multiple
    regressions due to cacheline cooldown.
    The only choice in cacheline hot sensitive areas is to deal with the
    complexity that comes with SLAB_DESTROY_BY_RCU or give up on RCU."

  - Because udp sockets are allocated from dedicated kmem_cache,
  use of SLAB_DESTROY_BY_RCU can help here.

Theory of operation :
---------------------

As the lookup is lockfree (using rcu_read_lock()/rcu_read_unlock()),
special attention must be taken by readers and writers.

Use of SLAB_DESTROY_BY_RCU is tricky too, because a socket can be freed,
reused, inserted in a different chain or in worst case in the same chain
while readers could do lookups in the same time.

In order to avoid loops, a reader must check each socket found in a chain
really belongs to the chain the reader was traversing. If it finds a
mismatch, lookup must start again at the begining. This *restart* loop
is the reason we had to use rdlock for the multicast case, because
we dont want to send same message several times to the same socket.

We use RCU only for fast path.
Thus, /proc/net/udp still takes spinlocks.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29 02:11:14 -07:00
Eric Dumazet
645ca708f9 udp: introduce struct udp_table and multiple spinlocks
UDP sockets are hashed in a 128 slots hash table.

This hash table is protected by *one* rwlock.

This rwlock is readlocked each time an incoming UDP message is handled.

This rwlock is writelocked each time a socket must be inserted in
hash table (bind time), or deleted from this table (close time)

This is not scalable on SMP machines :

1) Even in read mode, lock() and unlock() are atomic operations and
 must dirty a contended cache line, shared by all cpus.

2) A writer might be starved if many readers are 'in flight'. This can
 happen on a machine with some NIC receiving many UDP messages. User
 process can be delayed a long time at socket creation/dismantle time.

This patch prepares RCU migration, by introducing 'struct udp_table
and struct udp_hslot', and using one spinlock per chain, to reduce
contention on central rwlock.

Introducing one spinlock per chain reduces latencies, for port
randomization on heavily loaded UDP servers. This also speedup
bindings to specific ports.

udp_lib_unhash() was uninlined, becoming to big.

Some cleanups were done to ease review of following patch
(RCUification of UDP Unicast lookups)

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29 01:41:45 -07:00
Harvey Harrison
0c6ce78abf net: replace uses of NIP6_FMT with %p6
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-28 23:02:31 -07:00
Harvey Harrison
b071195deb net: replace all current users of NIP6_SEQFMT with %#p6
The define in kernel.h can be done away with at a later time.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-28 16:05:40 -07:00
Alexey Dobriyan
def8b4faff net: reduce structures when XFRM=n
ifdef out
* struct sk_buff::sp		(pointer)
* struct dst_entry::xfrm	(pointer)
* struct sock::sk_policy	(2 pointers)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-28 13:24:06 -07:00