History log of /net/openvswitch/flow.c
Revision Date Author Comments
25ef1328a03c72a7285883d5b337c4b602476ecd 17-Oct-2014 Pravin B Shelar <pshelar@nicira.com> openvswitch: Set flow-key members.

This patch adds missing memset which are required to initialize
flow key member. For example for IP flow we need to initialize
ip.frag for all cases.

Found by inspection.

This bug is introduced by commit 0714812134d7dcadeb7ecfbfeb18788aa7e1eaac
("openvswitch: Eliminate memset() from flow_extract").

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
389f48947a5a37ea283de520abb742d42174edb0 17-Oct-2014 Li RongQing <roy.qing.li@gmail.com> openvswitch: fix a use after free

pskb_may_pull() called by arphdr_ok can change skb->data, so put the arp
setting after arphdr_ok to avoid the use the freed memory

Fixes: 0714812134d7d ("openvswitch: Eliminate memset() from flow_extract.")
Cc: Jesse Gross <jesse@nicira.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
f5796684069e0c71c65bce6a6d4766114aec1396 04-Oct-2014 Jesse Gross <jesse@nicira.com> openvswitch: Add support for Geneve tunneling.

The Openvswitch implementation is completely agnostic to the options
that are in use and can handle newly defined options without
further work. It does this by simply matching on a byte array
of options and allowing userspace to setup flows on this array.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Singed-off-by: Ansis Atteka <aatteka@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Thomas Graf <tgraf@noironetworks.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
f0b128c1e2cc33ad104daf0f51a51e34f7763c5f 04-Oct-2014 Jesse Gross <jesse@nicira.com> openvswitch: Wrap struct ovs_key_ipv4_tunnel in a new structure.

Currently, the flow information that is matched for tunnels and
the tunnel data passed around with packets is the same. However,
as additional information is added this is not necessarily desirable,
as in the case of pointers.

This adds a new structure for tunnel metadata which currently contains
only the existing struct. This change is purely internal to the kernel
since the current OVS_KEY_ATTR_IPV4_TUNNEL is simply a compressed version
of OVS_KEY_ATTR_TUNNEL that is translated at flow setup.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
0714812134d7dcadeb7ecfbfeb18788aa7e1eaac 04-Oct-2014 Jesse Gross <jesse@nicira.com> openvswitch: Eliminate memset() from flow_extract.

As new protocols are added, the size of the flow key tends to
increase although few protocols care about all of the fields. In
order to optimize this for hashing and matching, OVS uses a variable
length portion of the key. However, when fields are extracted from
the packet we must still zero out the entire key.

This is no longer necessary now that OVS implements masking. Any
fields (or holes in the structure) which are not part of a given
protocol will be by definition not part of the mask and zeroed out
during lookup. Furthermore, since masking already uses variable
length keys this zeroing operation automatically benefits as well.

In principle, the only thing that needs to be done at this point
is remove the memset() at the beginning of flow. However, some
fields assume that they are initialized to zero, which now must be
done explicitly. In addition, in the event of an error we must also
zero out corresponding fields to signal that there is no valid data
present. These increase the total amount of code but very little of
it is executed in non-error situations.

Removing the memset() reduces the profile of ovs_flow_extract()
from 0.64% to 0.56% when tested with large packets on a 10G link.

Suggested-by: Pravin Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
971427f353f3c42c8dcef62e7124440df68eb809 16-Sep-2014 Andy Zhou <azhou@nicira.com> openvswitch: Add recirc and hash action.

Recirc action allows a packet to reenter openvswitch processing.
currently openvswitch lookup flow for packet received and execute
set of actions on that packet, with help of recirc action we can
process/modify the packet and recirculate it back in openvswitch
for another pass.

OVS hash action calculates 5-tupple hash and set hash in flow-key
hash. This can be used along with recirculation for distributing
packets among different ports for bond devices.
For example:
OVS bonding can use following actions:
Match on: bond flow; Action: hash, recirc(id)
Match on: recirc-id == id and hash lower bits == a;
Action: output port_bond_a

Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
8c8b1b83fcdd0f05e1f66ed6f8a2e831d5d374a2 16-Sep-2014 Pravin B Shelar <pshelar@nicira.com> openvswitch: Use tun_key only for egress tunnel path.

Currently tun_key is used for passing tunnel information
on ingress and egress path, this cause confusion. Following
patch removes its use on ingress path make it egress only parameter.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Andy Zhou <azhou@nicira.com>
83c8df26a3b654871c0503fcf6eac61777e12ea1 16-Sep-2014 Pravin B Shelar <pshelar@nicira.com> openvswitch: refactor ovs flow extract API.

OVS flow extract is called on packet receive or packet
execute code path. Following patch defines separate API
for extracting flow-key in packet execute code path.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Andy Zhou <azhou@nicira.com>
8c6b00c816191ded80d1ccd5164b53168255ec15 17-Aug-2014 Andreea-Cristina Bernat <bernat.ada@gmail.com> net/openvswitch/flow.c: Replace rcu_dereference() with rcu_access_pointer()

The "rcu_dereference()" call is used directly in a condition.
Since its return value is never dereferenced it is recommended to use
"rcu_access_pointer()" instead of "rcu_dereference()".
Therefore, this patch makes the replacement.

The following Coccinelle semantic patch was used:
@@
@@

(
if(
(<+...
- rcu_dereference
+ rcu_access_pointer
(...)
...+>)) {...}
|
while(
(<+...
- rcu_dereference
+ rcu_access_pointer
(...)
...+>)) {...}
)

Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ad55200734c65a3ec5d0c39d6ea904008baea536 07-May-2014 Ben Pfaff <blp@nicira.com> openvswitch: Fix tracking of flags seen in TCP flows.

Flow statistics need to take into account the TCP flags from the packet
currently being processed (in 'key'), not the TCP flags matched by the
flow found in the kernel flow table (in 'flow').

This bug made the Open vSwitch userspace fin_timeout action have no effect
in many cases.
This bug is introduced by commit 88d73f6c411ac2f0578 (openvswitch: Use
TCP flags in the flow key for stats.)

Reported-by: Len Gao <leng@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
86ec8dbae27e5fa2b5d54f10f77286d9ef55732a 05-May-2014 Jarno Rajahalme <jrajahalme@nicira.com> openvswitch: Fix ovs_flow_stats_get/clear RCU dereference.

For ovs_flow_stats_get() using ovsl_dereference() was wrong, since
flow dumps call this with RCU read lock.

ovs_flow_stats_clear() is always called with ovs_mutex, so can use
ovsl_dereference().

Also, make the ovs_flow_stats_get() 'flow' argument const to make
later patches cleaner.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
bb6f9a708d4067713afae2e9eb2637f6b4c01ecb 05-May-2014 Jarno Rajahalme <jrajahalme@nicira.com> openvswitch: Clarify locking.

Remove unnecessary locking from functions that are always called with
appropriate locking.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Thomas Graf <tgraf@redhat.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
1139e241ec436b9e9610c7a33ac5c6657f87fda1 05-May-2014 Jarno Rajahalme <jrajahalme@nicira.com> openvswitch: Compact sw_flow_key.

Minimize padding in sw_flow_key and move 'tp' top the main struct.
These changes simplify code when accessing the transport port numbers
and the tcp flags, and makes the sw_flow_key 8 bytes smaller on 64-bit
systems (128->120 bytes). These changes also make the keys for IPv4
packets to fit in one cache line.

There is a valid concern for safety of packing the struct
ovs_key_ipv4_tunnel, as it would be possible to take the address of
the tun_id member as a __be64 * which could result in unaligned access
in some systems. However:

- sw_flow_key itself is 64-bit aligned, so the tun_id within is
always
64-bit aligned.
- We never make arrays of ovs_key_ipv4_tunnel (which would force
every
second tun_key to be misaligned).
- We never take the address of the tun_id in to a __be64 *.
- Whereever we use struct ovs_key_ipv4_tunnel outside the
sw_flow_key,
it is in stack (on tunnel input functions), where compiler has full
control of the alignment.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
88d73f6c411ac2f057829b93b3cf202ee551f6cb 27-Mar-2014 Jarno Rajahalme <jrajahalme@nicira.com> openvswitch: Use TCP flags in the flow key for stats.

We already extract the TCP flags for the key, might as well use that
for stats.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
63e7959c4b9bd6f791061c460a22d9ee32ae2240 27-Mar-2014 Jarno Rajahalme <jrajahalme@nicira.com> openvswitch: Per NUMA node flow stats.

Keep kernel flow stats for each NUMA node rather than each (logical)
CPU. This avoids using the per-CPU allocator and removes most of the
kernel-side OVS locking overhead otherwise on the top of perf reports
and allows OVS to scale better with higher number of threads.

With 9 handlers and 4 revalidators netperf TCP_CRR test flow setup
rate doubles on a server with two hyper-threaded physical CPUs (16
logical cores each) compared to the current OVS master. Tested with
non-trivial flow table with a TCP port match rule forcing all new
connections with unique port numbers to OVS userspace. The IP
addresses are still wildcarded, so the kernel flows are not considered
as exact match 5-tuple flows. This type of flows can be expected to
appear in large numbers as the result of more effective wildcarding
made possible by improvements in OVS userspace flow classifier.

Perf results for this test (master):

Events: 305K cycles
+ 8.43% ovs-vswitchd [kernel.kallsyms] [k] mutex_spin_on_owner
+ 5.64% ovs-vswitchd [kernel.kallsyms] [k] __ticket_spin_lock
+ 4.75% ovs-vswitchd ovs-vswitchd [.] find_match_wc
+ 3.32% ovs-vswitchd libpthread-2.15.so [.] pthread_mutex_lock
+ 2.61% ovs-vswitchd [kernel.kallsyms] [k] pcpu_alloc_area
+ 2.19% ovs-vswitchd ovs-vswitchd [.] flow_hash_in_minimask_range
+ 2.03% swapper [kernel.kallsyms] [k] intel_idle
+ 1.84% ovs-vswitchd libpthread-2.15.so [.] pthread_mutex_unlock
+ 1.64% ovs-vswitchd ovs-vswitchd [.] classifier_lookup
+ 1.58% ovs-vswitchd libc-2.15.so [.] 0x7f4e6
+ 1.07% ovs-vswitchd [kernel.kallsyms] [k] memset
+ 1.03% netperf [kernel.kallsyms] [k] __ticket_spin_lock
+ 0.92% swapper [kernel.kallsyms] [k] __ticket_spin_lock
...

And after this patch:

Events: 356K cycles
+ 6.85% ovs-vswitchd ovs-vswitchd [.] find_match_wc
+ 4.63% ovs-vswitchd libpthread-2.15.so [.] pthread_mutex_lock
+ 3.06% ovs-vswitchd [kernel.kallsyms] [k] __ticket_spin_lock
+ 2.81% ovs-vswitchd ovs-vswitchd [.] flow_hash_in_minimask_range
+ 2.51% ovs-vswitchd libpthread-2.15.so [.] pthread_mutex_unlock
+ 2.27% ovs-vswitchd ovs-vswitchd [.] classifier_lookup
+ 1.84% ovs-vswitchd libc-2.15.so [.] 0x15d30f
+ 1.74% ovs-vswitchd [kernel.kallsyms] [k] mutex_spin_on_owner
+ 1.47% swapper [kernel.kallsyms] [k] intel_idle
+ 1.34% ovs-vswitchd ovs-vswitchd [.] flow_hash_in_minimask
+ 1.33% ovs-vswitchd ovs-vswitchd [.] rule_actions_unref
+ 1.16% ovs-vswitchd ovs-vswitchd [.] hindex_node_with_hash
+ 1.16% ovs-vswitchd ovs-vswitchd [.] do_xlate_actions
+ 1.09% ovs-vswitchd ovs-vswitchd [.] ofproto_rule_ref
+ 1.01% netperf [kernel.kallsyms] [k] __ticket_spin_lock
...

There is a small increase in kernel spinlock overhead due to the same
spinlock being shared between multiple cores of the same physical CPU,
but that is barely visible in the netperf TCP_CRR test performance
(maybe ~1% performance drop, hard to tell exactly due to variance in
the test results), when testing for kernel module throughput (with no
userspace activity, handful of kernel flows).

On flow setup, a single stats instance is allocated (for the NUMA node
0). As CPUs from multiple NUMA nodes start updating stats, new
NUMA-node specific stats instances are allocated. This allocation on
the packet processing code path is made to never block or look for
emergency memory pools, minimizing the allocation latency. If the
allocation fails, the existing preallocated stats instance is used.
Also, if only CPUs from one NUMA-node are updating the preallocated
stats instance, no additional stats instances are allocated. This
eliminates the need to pre-allocate stats instances that will not be
used, also relieving the stats reader from the burden of reading stats
that are never used.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
23dabf88abb48a866fdb19ee08ebcf1ddd9b1840 27-Mar-2014 Jarno Rajahalme <jrajahalme@nicira.com> openvswitch: Remove 5-tuple optimization.

The 5-tuple optimization becomes unnecessary with a later per-NUMA
node stats patch. Remove it first to make the changes easier to
grasp.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
8c63ff09bddf944ab0033fea97aacfadfffa76de 18-Feb-2014 Joe Perches <joe@perches.com> openvswitch: Use ether_addr_copy

It's slightly smaller/faster for some architectures.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
4f647e0a3c37b8d5086214128614a136064110c3 27-Mar-2014 Flavio Leitner <fbl@redhat.com> openvswitch: fix a possible deadlock and lockdep warning

There are two problematic situations.

A deadlock can happen when is_percpu is false because it can get
interrupted while holding the spinlock. Then it executes
ovs_flow_stats_update() in softirq context which tries to get
the same lock.

The second sitation is that when is_percpu is true, the code
correctly disables BH but only for the local CPU, so the
following can happen when locking the remote CPU without
disabling BH:

CPU#0 CPU#1
ovs_flow_stats_get()
stats_read()
+->spin_lock remote CPU#1 ovs_flow_stats_get()
| <interrupted> stats_read()
| ... +--> spin_lock remote CPU#0
| | <interrupted>
| ovs_flow_stats_update() | ...
| spin_lock local CPU#0 <--+ ovs_flow_stats_update()
+---------------------------------- spin_lock local CPU#1

This patch disables BH for both cases fixing the deadlocks.
Acked-by: Jesse Gross <jesse@nicira.com>

=================================
[ INFO: inconsistent lock state ]
3.14.0-rc8-00007-g632b06a #1 Tainted: G I
---------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
swapper/0/0 [HC0[0]:SC1[5]:HE1:SE0] takes:
(&(&cpu_stats->lock)->rlock){+.?...}, at: [<ffffffffa05dd8a1>] ovs_flow_stats_update+0x51/0xd0 [openvswitch]
{SOFTIRQ-ON-W} state was registered at:
[<ffffffff810f973f>] __lock_acquire+0x68f/0x1c40
[<ffffffff810fb4e2>] lock_acquire+0xa2/0x1d0
[<ffffffff817d8d9e>] _raw_spin_lock+0x3e/0x80
[<ffffffffa05dd9e4>] ovs_flow_stats_get+0xc4/0x1e0 [openvswitch]
[<ffffffffa05da855>] ovs_flow_cmd_fill_info+0x185/0x360 [openvswitch]
[<ffffffffa05daf05>] ovs_flow_cmd_build_info.constprop.27+0x55/0x90 [openvswitch]
[<ffffffffa05db41d>] ovs_flow_cmd_new_or_set+0x4dd/0x570 [openvswitch]
[<ffffffff816c245d>] genl_family_rcv_msg+0x1cd/0x3f0
[<ffffffff816c270e>] genl_rcv_msg+0x8e/0xd0
[<ffffffff816c0239>] netlink_rcv_skb+0xa9/0xc0
[<ffffffff816c0798>] genl_rcv+0x28/0x40
[<ffffffff816bf830>] netlink_unicast+0x100/0x1e0
[<ffffffff816bfc57>] netlink_sendmsg+0x347/0x770
[<ffffffff81668e9c>] sock_sendmsg+0x9c/0xe0
[<ffffffff816692d9>] ___sys_sendmsg+0x3a9/0x3c0
[<ffffffff8166a911>] __sys_sendmsg+0x51/0x90
[<ffffffff8166a962>] SyS_sendmsg+0x12/0x20
[<ffffffff817e3ce9>] system_call_fastpath+0x16/0x1b
irq event stamp: 1740726
hardirqs last enabled at (1740726): [<ffffffff8175d5e0>] ip6_finish_output2+0x4f0/0x840
hardirqs last disabled at (1740725): [<ffffffff8175d59b>] ip6_finish_output2+0x4ab/0x840
softirqs last enabled at (1740674): [<ffffffff8109be12>] _local_bh_enable+0x22/0x50
softirqs last disabled at (1740675): [<ffffffff8109db05>] irq_exit+0xc5/0xd0

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&(&cpu_stats->lock)->rlock);
<Interrupt>
lock(&(&cpu_stats->lock)->rlock);

*** DEADLOCK ***

5 locks held by swapper/0/0:
#0: (((&ifa->dad_timer))){+.-...}, at: [<ffffffff810a7155>] call_timer_fn+0x5/0x320
#1: (rcu_read_lock){.+.+..}, at: [<ffffffff81788a55>] mld_sendpack+0x5/0x4a0
#2: (rcu_read_lock_bh){.+....}, at: [<ffffffff8175d149>] ip6_finish_output2+0x59/0x840
#3: (rcu_read_lock_bh){.+....}, at: [<ffffffff8168ba75>] __dev_queue_xmit+0x5/0x9b0
#4: (rcu_read_lock){.+.+..}, at: [<ffffffffa05e41b5>] internal_dev_xmit+0x5/0x110 [openvswitch]

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G I 3.14.0-rc8-00007-g632b06a #1
Hardware name: /DX58SO, BIOS SOX5810J.86A.5599.2012.0529.2218 05/29/2012
0000000000000000 0fcf20709903df0c ffff88042d603808 ffffffff817cfe3c
ffffffff81c134c0 ffff88042d603858 ffffffff817cb6da 0000000000000005
ffffffff00000001 ffff880400000000 0000000000000006 ffffffff81c134c0
Call Trace:
<IRQ> [<ffffffff817cfe3c>] dump_stack+0x4d/0x66
[<ffffffff817cb6da>] print_usage_bug+0x1f4/0x205
[<ffffffff810f7f10>] ? check_usage_backwards+0x180/0x180
[<ffffffff810f8963>] mark_lock+0x223/0x2b0
[<ffffffff810f96d3>] __lock_acquire+0x623/0x1c40
[<ffffffff810f5707>] ? __lock_is_held+0x57/0x80
[<ffffffffa05e26c6>] ? masked_flow_lookup+0x236/0x250 [openvswitch]
[<ffffffff810fb4e2>] lock_acquire+0xa2/0x1d0
[<ffffffffa05dd8a1>] ? ovs_flow_stats_update+0x51/0xd0 [openvswitch]
[<ffffffff817d8d9e>] _raw_spin_lock+0x3e/0x80
[<ffffffffa05dd8a1>] ? ovs_flow_stats_update+0x51/0xd0 [openvswitch]
[<ffffffffa05dd8a1>] ovs_flow_stats_update+0x51/0xd0 [openvswitch]
[<ffffffffa05dcc64>] ovs_dp_process_received_packet+0x84/0x120 [openvswitch]
[<ffffffff810f93f7>] ? __lock_acquire+0x347/0x1c40
[<ffffffffa05e3bea>] ovs_vport_receive+0x2a/0x30 [openvswitch]
[<ffffffffa05e4218>] internal_dev_xmit+0x68/0x110 [openvswitch]
[<ffffffffa05e41b5>] ? internal_dev_xmit+0x5/0x110 [openvswitch]
[<ffffffff8168b4a6>] dev_hard_start_xmit+0x2e6/0x8b0
[<ffffffff8168be87>] __dev_queue_xmit+0x417/0x9b0
[<ffffffff8168ba75>] ? __dev_queue_xmit+0x5/0x9b0
[<ffffffff8175d5e0>] ? ip6_finish_output2+0x4f0/0x840
[<ffffffff8168c430>] dev_queue_xmit+0x10/0x20
[<ffffffff8175d641>] ip6_finish_output2+0x551/0x840
[<ffffffff8176128a>] ? ip6_finish_output+0x9a/0x220
[<ffffffff8176128a>] ip6_finish_output+0x9a/0x220
[<ffffffff8176145f>] ip6_output+0x4f/0x1f0
[<ffffffff81788c29>] mld_sendpack+0x1d9/0x4a0
[<ffffffff817895b8>] mld_send_initial_cr.part.32+0x88/0xa0
[<ffffffff817691b0>] ? addrconf_dad_completed+0x220/0x220
[<ffffffff8178e301>] ipv6_mc_dad_complete+0x31/0x50
[<ffffffff817690d7>] addrconf_dad_completed+0x147/0x220
[<ffffffff817691b0>] ? addrconf_dad_completed+0x220/0x220
[<ffffffff8176934f>] addrconf_dad_timer+0x19f/0x1c0
[<ffffffff810a71e9>] call_timer_fn+0x99/0x320
[<ffffffff810a7155>] ? call_timer_fn+0x5/0x320
[<ffffffff817691b0>] ? addrconf_dad_completed+0x220/0x220
[<ffffffff810a76c4>] run_timer_softirq+0x254/0x3b0
[<ffffffff8109d47d>] __do_softirq+0x12d/0x480

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
f9b8c4c8baded129535d82d74df8e87a7a369f54 20-Mar-2014 Ben Pfaff <blp@nicira.com> openvswitch: Correctly report flow used times for first 5 minutes after boot.

The kernel starts out its "jiffies" timer as 5 minutes below zero, as
shown in include/linux/jiffies.h:

/*
* Have the 32 bit jiffies value wrap 5 minutes after boot
* so jiffies wrap bugs show up earlier.
*/
#define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ))

The loop in ovs_flow_stats_get() starts out with 'used' set to 0, then
takes any "later" time. This means that for the first five minutes after
boot, flows will always be reported as never used, since 0 is greater than
any time already seen.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
04382a3303c22b0c536fbd0c94c1f012f2b8ed60 16-Feb-2014 Jarno Rajahalme <jrajahalme@nicira.com> openvswitch: Read tcp flags only then the tranport header is present.

Only the first IP fragment can have a TCP header, check for this.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
e298e505700604c97e6a9edb21cebb080bdb91f6 30-Oct-2013 Pravin B Shelar <pshelar@nicira.com> openvswitch: Per cpu flow stats.

With mega flow implementation ovs flow can be shared between
multiple CPUs which makes stats updates highly contended
operation. This patch uses per-CPU stats in cases where a flow
is likely to be shared (if there is a wildcard in the 5-tuple
and therefore likely to be spread by RSS). In other situations,
it uses the current strategy, saving memory and allocation time.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
5eb26b156e29eadcc21f73fb5d14497f0db24b86 23-Oct-2013 Jarno Rajahalme <jrajahalme@nicira.com> openvswitch: TCP flags matching support.

tcp_flags=flags/mask
Bitwise match on TCP flags. The flags and mask are 16-bit num‐
bers written in decimal or in hexadecimal prefixed by 0x. Each
1-bit in mask requires that the corresponding bit in port must
match. Each 0-bit in mask causes the corresponding bit to be
ignored.

TCP protocol currently defines 9 flag bits, and additional 3
bits are reserved (must be transmitted as zero), see RFCs 793,
3168, and 3540. The flag bits are, numbering from the least
significant bit:

0: FIN No more data from sender.

1: SYN Synchronize sequence numbers.

2: RST Reset the connection.

3: PSH Push function.

4: ACK Acknowledgement field significant.

5: URG Urgent pointer field significant.

6: ECE ECN Echo.

7: CWR Congestion Windows Reduced.

8: NS Nonce Sum.

9-11: Reserved.

12-15: Not matchable, must be zero.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
df23e9f642830f10c505c8a3d57772ad1238c701 23-Oct-2013 Jarno Rajahalme <jrajahalme@nicira.com> openvswitch: Widen TCP flags handling.

Widen TCP flags handling from 7 bits (uint8_t) to 12 bits (uint16_t).
The kernel interface remains at 8 bits, which makes no functional
difference now, as none of the higher bits is currently of interest
to the userspace.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
e64457191a259537bbbfaebeba9a8043786af96f 04-Oct-2013 Pravin B Shelar <pshelar@nicira.com> openvswitch: Restructure datapath.c and flow.c

Over the time datapath.c and flow.c has became pretty large files.
Following patch restructures functionality of component into three
different components:

flow.c: contains flow extract.
flow_netlink.c: netlink flow api.
flow_table.c: flow table api.

This patch restructures code without changing logic.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
3bf4b5b11d381fed6a94a7e487e01c8b3bc436b9 07-Sep-2013 Daniel Borkmann <dborkman@redhat.com> net: ovs: flow: fix potential illegal memory access in __parse_flow_nlattrs

In function __parse_flow_nlattrs(), we check for condition
(type > OVS_KEY_ATTR_MAX) and if true, print an error, but we do
not return from this function as in other checks. It seems this
has been forgotten, as otherwise, we could access beyond the
memory of ovs_key_lens, which is of ovs_key_lens[OVS_KEY_ATTR_MAX + 1].
Hence, a maliciously prepared nla_type from user space could access
beyond this upper limit.

Introduced by 03f0d916a ("openvswitch: Mega flow implementation").

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Andy Zhou <azhou@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
0d40f75bdab241868c0eb6f97aef9f8b3a66f7b3 05-Sep-2013 Jesse Gross <jesse@nicira.com> openvswitch: Fix alignment of struct sw_flow_key.

sw_flow_key alignment was declared as " __aligned(__alignof__(long))".
However, this breaks on the m68k architecture where long is 32 bit in
size but 16 bit aligned by default. This aligns to the size of a long to
ensure that we can always do comparsions in full long-sized chunks. It
also adds an additional build check to catch any reduction in alignment.

CC: Andy Zhou <azhou@nicira.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
5828cd9a68873df1340b420371c02c47647878fb 27-Aug-2013 Andy Zhou <azhou@nicira.com> openvswitch: optimize flow compare and mask functions

Make sure the sw_flow_key structure and valid mask boundaries are always
machine word aligned. Optimize the flow compare and mask operations
using machine word size operations. This patch improves throughput on
average by 15% when CPU is the bottleneck of forwarding packets.

This patch is inspired by ideas and code from a patch submitted by Peter
Klausler titled "replace memcmp() with specialized comparator".
However, The original patch only optimizes for architectures
support unaligned machine word access. This patch optimizes for all
architectures.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
02237373b1c61a09a4db329545e39cffc48910d5 22-Aug-2013 Andy Zhou <azhou@nicira.com> openvswitch: Rename key_len to key_end

Key_end is a better name describing the ending boundary than key_len.
Rename those variables to make it less confusing.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
a175a723301a8a4a9fedf9ce5b8ca586e7a97b40 22-Aug-2013 Joe Stringer <joe@wand.net.nz> openvswitch: Add SCTP support

This patch adds support for rewriting SCTP src,dst ports similar to the
functionality already available for TCP/UDP.

Rewriting SCTP ports is expensive due to double-recalculation of the
SCTP checksums; this is performed to ensure that packets traversing OVS
with invalid checksums will continue to the destination with any
checksum corruption intact.

Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Signed-off-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
03f0d916aa0317592dda11bd17c7357858719b6c 08-Aug-2013 Andy Zhou <azhou@nicira.com> openvswitch: Mega flow implementation

Add wildcarded flow support in kernel datapath.

Wildcarded flow can improve OVS flow set up performance by avoid sending
matching new flows to the user space program. The exact performance boost
will largely dependent on wildcarded flow hit rate.

In case all new flows hits wildcard flows, the flow set up rate is
within 5% of that of linux bridge module.

Pravin has made significant contributions to this patch. Including API
clean ups and bug fixes.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
76a66c7e7f6bec35bbdb0ca91db327c7c56d8c45 31-Jul-2013 Pravin B Shelar <pshelar@nicira.com> openvswitch: Use non rcu hlist_del() flow table entry.

Flow table destroy is done in rcu call-back context. Therefore
there is no need to use rcu variant of hlist_del().

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
42415c90ceaf50c792e29823e359463bc6d4ee05 31-Jul-2013 Pravin B Shelar <pshelar@nicira.com> openvswitch: Use correct type while allocating flex array.

Flex array is used to allocate hash buckets which is type struct
hlist_head, but we use `struct hlist_head *` to calculate
array size. Since hlist_head is of size pointer it works fine.

Following patch use correct type.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
a3e82996a8874c4cfe8c7f1be4d552018d8cba7e 18-Jun-2013 Pravin B Shelar <pshelar@nicira.com> openvswitch: Optimize flow key match for non tunnel flows.

Following patch adds start offset for sw_flow-key, so that we can
skip tunneling information in key for non-tunnel flows.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
7d5437c709ded4f152cb8b305d17972d6707f20c 18-Jun-2013 Pravin B Shelar <pshelar@nicira.com> openvswitch: Add tunneling interface.

Add ovs tunnel interface for set tunnel action for userspace.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
74f84a5726c7d08c27745305e67474b8645c541d 18-Jun-2013 Pravin B Shelar <pshelar@nicira.com> openvswitch: Copy individual actions.

Rather than validating actions and then copying all actiaons
in one block, following patch does same operation in single pass.
This validate and copy action one by one. This is required for
ovs tunneling patch.

This patch does not change any functionality.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
93d8fd1514b6862c3370ea92be3f3b4216e0bf8f 13-Jun-2013 Pravin B Shelar <pshelar@nicira.com> openvswitch: Simplify interface ovs_flow_metadata_from_nlattrs()

This is not functional change, this is just code cleanup.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
b34df5e805a6e98cae0bc5bc80c1b52d9ff811de 13-Jun-2013 Pravin B Shelar <pshelar@nicira.com> openvswitch: make skb->csum consistent with rest of networking stack.

Following patch keeps skb->csum correct across ovs.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
34d94f2102fb361030569eb983751ed80742f6e9 03-Jun-2013 Lorand Jakab <lojakab@cisco.com> openvswitch: fix variable names in comment

Signed-off-by: Lorand Jakab <lojakab@cisco.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
32686a9d2988516788cfcc402e1355c1eba1186a 29-Mar-2013 Thomas Graf <tgraf@suug.ch> openvswitch: Use nla_memcpy() to memcpy() data from attributes

Less error prone as it takes into account the length of both the
destination buffer and the source attribute and documents when
data is copied from an attribute.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Jesse Gross <jesse@nicira.com>
e5c5d22e8dcf7c2d430336cbf8e180bd38e8daf1 28-Mar-2013 Simon Horman <horms@verge.net.au> net: add ETH_P_802_3_MIN

Add a new constant ETH_P_802_3_MIN, the minimum ethernet type for
an 802.3 frame. Frames with a lower value in the ethernet type field
are Ethernet II.

Also update all the users of this value that David Miller and
I could find to use the new constant.

Also correct a bug in util.c. The comparison with ETH_P_802_3_MIN
should be >= not >.

As suggested by Jesse Gross.

Compile tested only.

Cc: David Miller <davem@davemloft.net>
Cc: Jesse Gross <jesse@nicira.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Bart De Schuymer <bart.de.schuymer@pandora.be>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: linux-bluetooth@vger.kernel.org
Cc: netfilter-devel@vger.kernel.org
Cc: bridge@lists.linux-foundation.org
Cc: linux-wireless@vger.kernel.org
Cc: linux1394-devel@lists.sourceforge.net
Cc: linux-media@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: dev@openvswitch.org
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
d3e1101c9b75574e68380b5cb10c9395fd8855de 27-Mar-2013 Hong Zhiguo <honkiko@gmail.com> openvswitch: correct an invalid BUG_ON

table->count is uint32_t

Signed-off-by: Hong Zhiguo <honkiko@gmail.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
b67bfe0d42cac56c512dd5da4b1b347a23f4b70a 28-Feb-2013 Sasha Levin <sasha.levin@oracle.com> hlist: drop the node parameter from iterators

I'm not sure why, but the hlist for each entry iterators were conceived

list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

- Fix up the actual hlist iterators in linux/list.h
- Fix up the declaration of other iterators based on the hlist ones.
- A very small amount of places were using the 'node' parameter, this
was modified to use 'obj->member' instead.
- Coccinelle didn't handle the hlist_for_each_entry_safe iterator
properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
<+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
17b682a04841233f827073b327c6533e478dfcd4 19-Feb-2013 Rich Lane <rlane@bigswitch.com> openvswitch: Fix parsing invalid LLC/SNAP ethertypes

Before this patch, if an LLC/SNAP packet with OUI 00:00:00 had an
ethertype less than 1536 the flow key given to userspace in the upcall
would contain the invalid ethertype (for example, 3). If userspace
attempted to insert a kernel flow for this key it would be rejected
by ovs_flow_from_nlattrs.

This patch allows OVS to pass the OFTest pktact.DirectBadLlcPackets.

Signed-off-by: Rich Lane <rlane@bigswitch.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
39c7caebc94e851f58b84b54659156dd30522e8e 26-Nov-2012 Ansis Atteka <aatteka@nicira.com> openvswitch: add skb mark matching and set action

This patch adds support for skb mark matching and set action.

Signed-off-by: Ansis Atteka <aatteka@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
c0618533815d8d92b270f03c11042ea53a8045d2 02-Nov-2012 Mehak Mahajan <mmahajan@nicira.com> openvswitch: Process RARP packets with ethertype 0x8035 similar to ARP packets.

With this commit, OVS will match the data in the RARP packets having
ethertype 0x8035, in the same way as the data in the ARP packets.

Signed-off-by: Mehak Mahajan <mmahajan@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
d04d382980c86bdee9960c3eb157a73f8ed230cc 30-Oct-2012 Mehak Mahajan <mmahajan@nicira.com> openvswitch: Store flow key len if ARP opcode is not request or reply.

We currently only extract the ARP payload if the opcode indicates
that it is a request or reply. However, we also only set the
key length in these situations even though it should still be
possible to match on the opcode. There's no real reason to
restrict the ARP opcode since all have the same format so this
simply removes the check.

Signed-off-by: Mehak Mahajan <mmahajan@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
15eac2a74277bc7de68a7c2a64a7c91b4b6f5961 23-Aug-2012 Pravin B Shelar <pshelar@nicira.com> openvswitch: Increase maximum number of datapath ports.

Use hash table to store ports of datapath. Allow 64K ports per switch.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
80f0fd8a7f18af78dd26bf94230e89c3ae82d4ba 26-Aug-2012 Wei Yongjun <yongjun_wei@trendmicro.com.cn> openvswitch: using kfree_rcu() to simplify the code

The callback function of call_rcu() just calls a kfree(), so we
can use kfree_rcu() instead of call_rcu() + callback function.

spatch with a semantic match is used to found this problem.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
caf2ee14bbc2c6bd73cf0decf576007e0239a482 04-May-2012 Raju Subramanian <rsubramanian@nicira.com> openvswitch: Replace Nicira Networks.

Replaced all instances of Nicira Networks(, Inc) to Nicira, Inc.

Signed-off-by: Raju Subramanian <rsubramanian@nicira.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
c55177e3e1e8a89d9d810d95ac18cb104865322c 03-Apr-2012 Jesse Gross <jesse@nicira.com> openvswitch: Enable retrieval of TCP flags from IPv6 traffic.

We currently check that a packet is IPv4 and TCP before fetching the
TCP flags. This enables fetching from IPv6 packets as well.

Reported-by: Michael Mao <mmao@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
bf32fecdc1851ad9ca960f56771b798d17c26cf1 02-Apr-2012 Jesse Gross <jesse@nicira.com> openvswitch: Add length check when retrieving TCP flags.

When collecting TCP flags we check that the IP header indicates that
a TCP header is present but not that the packet is actually long
enough to contain the header. This adds a check to prevent reading
off the end of the packet.

In practice, this is only likely to result in reading of bad data and
not a crash due to the presence of struct skb_shared_info at the end
of the packet.

Signed-off-by: Jesse Gross <jesse@nicira.com>
028d6a6767456d6c84a72d3451f19fe7ca7b47db 30-Mar-2012 David S. Miller <davem@davemloft.net> openvswitch: Stop using NLA_PUT*().

These macros contain a hidden goto, and are thus extremely error
prone and make code hard to audit.

Signed-off-by: David S. Miller <davem@davemloft.net>
2b2d465631db59c144f537a9bef47a883c55d670 16-Jan-2012 Shan Wei <davidshan@tencent.com> net: kill duplicate included header

For net part, remove duplicate included header.

Signed-off-by: Shan Wei <davidshan@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ccb1352e76cff0524e7ccb2074826a092dd13016 26-Oct-2011 Jesse Gross <jesse@nicira.com> net: Add Open vSwitch kernel components.

Open vSwitch is a multilayer Ethernet switch targeted at virtualized
environments. In addition to supporting a variety of features
expected in a traditional hardware switch, it enables fine-grained
programmatic extension and flow-based control of the network.
This control is useful in a wide variety of applications but is
particularly important in multi-server virtualization deployments,
which are often characterized by highly dynamic endpoints and the need
to maintain logical abstractions for multiple tenants.

The Open vSwitch datapath provides an in-kernel fast path for packet
forwarding. It is complemented by a userspace daemon, ovs-vswitchd,
which is able to accept configuration from a variety of sources and
translate it into packet processing rules.

See http://openvswitch.org for more information and userspace
utilities.

Signed-off-by: Jesse Gross <jesse@nicira.com>