The NL_SET_ERR_MSG_MOD macro is used to report a string describing an
error message to userspace via the netlink extended ACK structure. It
should not have a trailing newline.
Add a cocci script which catches cases where the newline marker is
present. Using this script, fix the handful of cases which accidentally
included a trailing new line.
I couldn't figure out a way to get a patch mode working, so this script
only implements context, report, and org.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is not possible to have the MRP and STP running at the same time on the
bridge, therefore add check when enabling the STP to check if MRP is already
enabled. In that case return error.
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We can optimize the fdb convergence when a backup_port is present by not
immediately flushing the entries of the stopped port since traffic for
those entries will flow towards the backup_port.
There are 2 cases specifically that benefit most:
- when the stopped port comes up before the entries expire by themselves
- when there's an external entry refresh and they're kept while the
backup_port is operating (e.g. mlag)
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the bridge device doesn't generate any notifications upon vlan
modifications on itself because it doesn't use the generic bridge
notifications.
With the recent changes we know if anything was modified in the vlan config
thus we can generate a notification when necessary for the bridge device
so add support to br_ifinfo_notify() similar to how other combined
functions are done - if port is present it takes precedence, otherwise
notify about the bridge. I've explicitly marked the locations where the
notification should be always for the port by setting bridge to NULL.
I've also taken the liberty to rearrange each modified function's local
variables in reverse xmas tree as well.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the transition of NO_STP -> KERNEL_STP was fixed by always calling
mod_timer in br_stp_start, it introduced a new regression which causes
the timer to be armed even when the bridge is down, and since we stop
the timers in its ndo_stop() function, they never get disabled if the
device is destroyed before it's upped.
To reproduce:
$ while :; do ip l add br0 type bridge hello_time 100; brctl stp br0 on;
ip l del br0; done;
CC: Xin Long <lucien.xin@gmail.com>
CC: Ivan Vecera <cera@cera.cz>
CC: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Fixes: 6d18c732b9 ("bridge: start hello_timer when enabling KERNEL_STP in br_stp_start")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Current bridge code incorrectly handles starting/stopping of hello and
hold timers during STP enable/disable.
1. Timers are stopped in br_stp_start() during NO_STP->USER_STP
transition. The timers are already stopped in NO_STP state so
this is confusing no-op.
2. During USER_STP->NO_STP transition the timers are started. This
does not make sense and is confusion because the timer should not be
active in NO_STP state.
Cc: davem@davemloft.net
Cc: sashok@cumulusnetworks.com
Cc: stephen@networkplumber.org
Cc: bridge@lists.linux-foundation.org
Cc: lucien.xin@gmail.com
Cc: nikolay@cumulusnetworks.com
Signed-off-by: Ivan Vecera <cera@cera.cz>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit 76b91c32dd ("bridge: stp: when using userspace stp stop
kernel hello and hold timers"), bridge would not start hello_timer if
stp_enabled is not KERNEL_STP when br_dev_open.
The problem is even if users set stp_enabled with KERNEL_STP later,
the timer will still not be started. It causes that KERNEL_STP can
not really work. Users have to re-ifup the bridge to avoid this.
This patch is to fix it by starting br->hello_timer when enabling
KERNEL_STP in br_stp_start.
As an improvement, it's also to start hello_timer again only when
br->stp_enabled is KERNEL_STP in br_hello_timer_expired, there is
no reason to start the timer again when it's NO_STP.
Fixes: 76b91c32dd ("bridge: stp: when using userspace stp stop kernel hello and hold timers")
Reported-by: Haidong Li <haili@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Ivan Vecera <cera@cera.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the fdb garbage collector to a workqueue which fires at least 10
milliseconds apart and cleans chain by chain allowing for other tasks
to run in the meantime. When having thousands of fdbs the system is much
more responsive. Most importantly remove the need to check if the
matched entry has expired in __br_fdb_get that causes false-sharing and
is completely unnecessary if we cleanup entries, at worst we'll get 10ms
of traffic for that entry before it gets deleted.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a __br_set_topology_change helper to set the topology change value.
This can be later extended to add actions when the topology change flag
is set or cleared.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME switchdev attr is actually set
when initializing a bridge port, and when configuring the bridge ageing
time from ioctl/netlink/sysfs.
Add a __set_ageing_time helper to offload the ageing time to physical
switches, and add the SWITCHDEV_F_DEFER flag since it can be called
under bridge lock.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If /sbin/bridge-stp is available on the system, bridge tries to execute
it instead of the kernel implementation when starting/stopping STP.
If anything goes wrong with /sbin/bridge-stp, bridge silently falls back
to kernel STP, making hard to debug userspace STP.
This patch adds a br_stp_call_user helper to start/stop userspace STP
and debug errors from the program: abnormal exit status is stored in the
lower byte and normal exit status is stored in higher byte.
Below is a simple example on a kernel with dynamic debug enabled:
# ln -s /bin/false /sbin/bridge-stp
# brctl stp br0 on
br0: failed to start userspace STP (256)
# dmesg
br0: /sbin/bridge-stp exited with code 1
br0: failed to start userspace STP (256)
br0: using kernel STP
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
br_stp_enable_bridge() does take the br->lock spinlock. Fix its wrongly
pasted comment and use the same as br_stp_disable_bridge().
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove the shared br_log_state function and print the info directly in
br_set_state, where the net_bridge_port state is actually changed.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[I stole this patch from Eric Biederman. He wrote:]
> There is no defined mechanism to pass network namespace information
> into /sbin/bridge-stp therefore don't even try to invoke it except
> for bridge devices in the initial network namespace.
>
> It is possible for unprivileged users to cause /sbin/bridge-stp to be
> invoked for any network device name which if /sbin/bridge-stp does not
> guard against unreasonable arguments or being invoked twice on the
> same network device could cause problems.
[Hannes: changed patch using netns_eq]
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The bridge's ageing time is offloaded to hardware when:
1) A port joins a bridge
2) The ageing time of the bridge is changed
In the first case the ageing time is offloaded as jiffies, but in the
second case it's offloaded as clock_t, which is what existing switchdev
drivers expect to receive.
Fixes: 6ac311ae8b ("Adding switchdev ageing notification on port bridged")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
switchdev drivers need to know the netdev on which the switchdev op was
invoked. For example, the STP state of a VLAN interface configured on top
of a port can change while being member in a bridge. In this case, the
underlying driver should only change the STP state of that particular
VLAN and not of all the VLANs configured on the port.
However, current switchdev infrastructure only passes the port netdev down
to the driver. Solve that by passing the original device down to the
driver as part of the required switchdev object / attribute.
This doesn't entail any change in current switchdev drivers. It simply
enables those supporting stacked devices to know the originating device
and act accordingly.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When NET_SWITCHDEV=n, switchdev_port_attr_set simply returns EOPNOTSUPP.
In this case we should not emit errors and warnings to the kernel log.
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: 0bc05d585d ("switchdev: allow caller to explicitly request
attr_set as deferred")
Fixes: 6ac311ae8b ("Adding switchdev ageing notification on port
bridged")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Configure ageing time to the HW for newly bridged device
CC: Scott Feldman <sfeldma@gmail.com>
CC: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Elad Raz <eladr@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These should be handled only by the respective STP which is in control.
They become problematic for devices with limited resources with many
ports because the hold_timer is per port and fires each second and the
hello timer fires each 2 seconds even though it's global. While in
user-space STP mode these timers are completely unnecessary so it's better
to keep them off.
Also ensure that when the bridge is up these timers are started only when
running with kernel STP.
Signed-off-by: Satish Ashok <sashok@cumulusnetworks.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new argument to br_fdb_delete_by_port which allows to specify a
vid to match when flushing entries and use it in nbp_vlan_delete() to
flush the dynamically learned entries of the vlan/port pair when removing
a vlan from a port. Before this patch only the local mac was being
removed and the dynamically learned ones were left to expire.
Note that the do_all argument is still respected and if specified, the
vid will be ignored.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After the ->set() spinlocks were removed br_stp_set_bridge_priority
was left running without any protection when used via sysfs. It can
race with port add/del and could result in use-after-free cases and
corrupted lists. Tested by running port add/del in a loop with stp
enabled while setting priority in a loop, crashes are easily
reproducible.
The spinlocks around sysfs ->set() were removed in commit:
14f98f258f ("bridge: range check STP parameters")
There's also a race condition in the netlink priority support that is
fixed by this change, but it was introduced recently and the fixes tag
covers it, just in case it's needed the commit is:
af615762e9 ("bridge: add ageing_time, stp_state, priority over netlink")
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Fixes: 14f98f258f ("bridge: range check STP parameters")
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation for being able to propagate port states to e.g: notifiers
or other kernel parts, do not manipulate the port state directly, but
instead use a helper function which will allow us to do a bit more than
just setting the state.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Vlan code may need fdb change when changing mac address of bridge device
even if it is caused by the mac address changing of a bridge port.
Example configuration:
ip link set eth0 address 12:34:56:78:90:ab
ip link set eth1 address aa:bb:cc:dd:ee:ff
brctl addif br0 eth0
brctl addif br0 eth1 # br0 will have mac address 12:34:56:78:90:ab
bridge vlan add dev br0 vid 10 self
bridge vlan add dev eth0 vid 10
We will have fdb entry such that f->dst == NULL, f->vlan_id == 10 and
f->addr == 12:34:56:78:90:ab at this time.
Next, change the mac address of eth0 to greater value.
ip link set eth0 address ee:ff:12:34:56:78
Then, mac address of br0 will be recalculated and set to aa:bb:cc:dd:ee:ff.
However, an entry aa:bb:cc:dd:ee:ff will not be created and we will be not
able to communicate using br0 on vlan 10.
Address this issue by deleting and adding local entries whenever
changing the mac address of the bridge device.
If there already exists an entry that has the same address, for example,
in case that br_fdb_changeaddr() has already inserted it,
br_fdb_change_mac_address() will simply fail to insert it and no
duplicated entry will be made, as it was.
This approach also needs br_add_if() to call br_fdb_insert() before
br_stp_recalculate_bridge_id() so that we don't create an entry whose
dst == NULL in this function to preserve previous behavior.
Note that this is a slight change in behavior where the bridge device can
receive the traffic to the new address before calling
br_stp_recalculate_bridge_id() in br_add_if().
However, it is not a problem because we have already the address on the
new port and such a way to insert new one before recalculating bridge id
is taken in br_device_event() as well.
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit be4f154d5e
bridge: Clamp forward_delay when enabling STP
had a typo when attempting to clamp maximum forward delay.
It is possible to set bridge_forward_delay to be higher then
permitted maximum when STP is off. When turning STP on, the
higher then allowed delay has to be clamed down to max value.
CC: Herbert Xu <herbert@gondor.apana.org.au>
CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Reviewed-by: Veaceslav Falico <vfalico@redhat.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
At some point limits were added to forward_delay. However, the
limits are only enforced when STP is enabled. This created a
scenario where you could have a value outside the allowed range
while STP is disabled, which then stuck around even after STP
is enabled.
This patch fixes this by clamping the value when we enable STP.
I had to move the locking around a bit to ensure that there is
no window where someone could insert a value outside the range
while we're in the middle of enabling STP.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cheers,
Signed-off-by: David S. Miller <davem@davemloft.net>
Keep a STP port path cost value if it was set by a user.
Don't replace it with the link-speed based path cost
whenever the link goes down and comes back up.
Reported-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
And remove no longer used br->flags.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The bridge link detection should follow the operational state
of the lower device, rather than the carrier bit. This allows devices
like tunnels that are controlled by userspace control plane to work
with bridge STP link management.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Reviewed-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use the new bool function ether_addr_equal to add
some clarity and reduce the likelihood for misuse
of compare_ether_addr for sorting.
Done via cocci script:
$ cat compare_ether_addr.cocci
@@
expression a,b;
@@
- !compare_ether_addr(a, b)
+ ether_addr_equal(a, b)
@@
expression a,b;
@@
- compare_ether_addr(a, b)
+ !ether_addr_equal(a, b)
@@
expression a,b;
@@
- !ether_addr_equal(a, b) == 0
+ ether_addr_equal(a, b)
@@
expression a,b;
@@
- !ether_addr_equal(a, b) != 0
+ !ether_addr_equal(a, b)
@@
expression a,b;
@@
- ether_addr_equal(a, b) == 0
+ !ether_addr_equal(a, b)
@@
expression a,b;
@@
- ether_addr_equal(a, b) != 0
+ ether_addr_equal(a, b)
@@
expression a,b;
@@
- !!ether_addr_equal(a, b)
+ ether_addr_equal(a, b)
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now we have:
eth0: link *down*
br0: port 1(eth0) entered *forwarding* state
br_log_state(p) should be called *after* p->state is set
to BR_STATE_DISABLED.
Reported-by: Zilvinas Valinskas <zilvinas@wilibox.com>
Signed-off-by: Paulius Zaleckas <paulius.zaleckas@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To fix this, once the implicit presence of module.h is removed:
net/bridge/br_stp_if.c: In function ‘br_stp_start’:
net/bridge/br_stp_if.c:131: error: implicit declaration of function ‘call_usermodehelper’
net/bridge/br_stp_if.c:131: error: ‘UMH_WAIT_PROC’ undeclared (first use in this function)
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
When STP changes state of interface need to send a new link
message to reflect that change.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Apply restrictions on STP parameters based 802.1D 1998 standard.
* Fixes missing locking in set path cost ioctl
* Uses common code for both ioctl and sysfs
This is based on an earlier patch Sasikanth V but with overhaul.
Note:
1. It does NOT enforce the restriction on the relationship max_age and
forward delay or hello time because in existing implementation these are
set as independant operations.
2. If STP is disabled, there is no restriction on forward delay
3. No restriction on holding time because users use Linux code to act
as hub or be sticky.
4. Although standard allow 0-255, Linux only allows 0-63 for port priority
because more bits are reserved for port number.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/bridge/br_stp_if.c: In function ‘br_stp_recalculate_bridge_id’:
net/bridge/br_stp_if.c:216:3: warning: ‘return’ with no value, in function returning non-void
Signed-off-by: G.Balaji <balajig81@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The mac address of the bridge device may be changed when a new interface
is added to the bridge. If this happens, then the bridge needs to call
the network notifiers to tickle any other systems that care. Since bridge
can be a module, this also means exporting the notifier function.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/bridge//br_stp_if.c:148:66: warning: conversion of
net/bridge//br_stp_if.c:148:66: int to
net/bridge//br_stp_if.c:148:66: int enum umh_wait
net/bridge//netfilter/ebtables.c:1150:30: warning: Using plain integer as NULL pointer
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use one set of macro's for all bridge messages.
Note: can't use netdev_XXX macro's because bridge is purely
virtual and has no device parent.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch hooks up the bridge start/stop and add/delete/disable
port functions to the new multicast module.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Normally, the bridge just chooses the smallest mac address as the
bridge id and mac address of bridge device. But if the administrator
has explictly set the interface address then don't change it.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes CVS keywords that weren't updated for a long time
from comments.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Acked-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rather than using a tri-state integer for the wait flag in
call_usermodehelper_exec, define a proper enum, and use that. I've
preserved the integer values so that any callers I've missed should
still work OK.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: David Howells <dhowells@redhat.com>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Need to tell STP daemon about more events, like any time a
device is added even when it is down.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
This patchset based on work by Aji_Srinivas@emc.com provides allows
spanning tree to be controled from userspace. Like hotplug, it
uses call_usermodehelper when spanning tree is enabled so there
is no visible API change. If call to start usermode STP fails
it falls back to existing kernel STP.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
