This patch moves neigh_setup and hard_start_xmit into the network device ops
structure. For bisection, fix all the previously converted drivers as well.
Bonding driver took the biggest hit on this.

Added a prefetch of the hard_start_xmit in the fast path to try and reduce
any impact this would have.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order for the network device ops get_stats call to be immutable, the handling
of the default internal network device stats block has to be changed. Add a new
helper function which replaces the old use of internal_get_stats.

Note: change return code to make it clear that the caller should not
go changing the returned statistics.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch changes the network device internal API to move adminstrative
operations out of the network device structure and into a separate structure.

This patch involves some hackery to maintain compatablity between the
new and old model, so all 300+ drivers don't have to be changed at once.
For drivers that aren't converted yet, the netdevice_ops virt function list
still resides in the net_device structure. For old protocols, the new
net_device_ops are copied out to the old net_device pointers.

After the transistion is completed the nag message can be changed to
an WARN_ON, and the compatiablity code can be made configurable.

Some function pointers aren't moved:
* destructor can't be in net_device_ops because
  it may need to be referenced after the module is unloaded.
* neighbor setup is manipulated in a couple of places that need special
  consideration
* hard_start_xmit is in the fast path for transmit.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Technically, patch changes format for modules, but I think nobody cares.

	-86dd          :ipv6:ipv6_rcv+0x0
	+86dd          ipv6_rcv+0x0/0x400 [ipv6]
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I was recently hunting a bug that occurred in network namespace
cleanup.  In looking at the code it became apparrent that we have
and will continue to have cases where if we have anything going
on in a network namespace there will be assumptions that the
loopback device is present.   Things like sending igmp unsubscribe
messages when we bring down network devices invokes the routing
code which assumes that at least the loopback driver is present.

Therefore to avoid magic initcall ordering hackery that is hard
to follow and hard to get right insert a call to register the
loopback device directly from net_dev_init().    This guarantes
that the loopback device is the first device registered and
the last network device to go away.

But do it carefully so we register the loopback device after
we clear dev_boot_phase.
Signed-off-by: NEric W. Biederman <ebiederm@maxwell.aristanetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit ae33bc40.

I have been tracking for a while a case where when the
network namespace exits the cleanup gets stck in an
endless precessess of:

unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3

It turns out that if you listen on a multicast address an unsubscribe
packet is sent when the network device goes down.   If you shutdown
the network namespace without carefully cleaning up this can trigger
the unsubscribe packet to be sent over the loopback interface while
the network namespace is going down.

All of which is fine except when we drop the packet and forget to
free it leaking the skb and the dst entry attached to.  As it
turns out the dst entry hold a reference to the idev which holds
the dev and keeps everything from being cleaned up.  Yuck!

By fixing my earlier thinko and add the needed kfree_skb and everything
cleans up beautifully. 
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I was recently hunting a bug that occurred in network namespace
cleanup.  In looking at the code it became apparrent that we have
and will continue to have cases where if we have anything going
on in a network namespace there will be assumptions that the
loopback device is present.   Things like sending igmp unsubscribe
messages when we bring down network devices invokes the routing
code which assumes that at least the loopback driver is present.

Therefore to avoid magic initcall ordering hackery that is hard
to follow and hard to get right insert a call to register the
loopback device directly from net_dev_init().    This guarantes
that the loopback device is the first device registered and
the last network device to go away.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When physical devices are inside of network namespace and that
network namespace terminates we can not make them go away.  We
have to keep them and moving them to the initial network namespace
is the best we can do.

For virtual devices left in a network namespace that is exiting
we have no need to preserve them and we now have the infrastructure
that allows us to delete them.  So delete virtual devices when we
exit a network namespace.  Keeping the necessary user space clean up
after a network namespace exits much more tractable.
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Acked-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The changes to deliver hardware accelerated VLAN packets to packet
sockets (commit bc1d0411) caused a warning for non-NAPI drivers.
The __vlan_hwaccel_rx() function is called directly from the drivers
RX function, for non-NAPI drivers that means its still in RX IRQ
context:

[   27.779463] ------------[ cut here ]------------
[   27.779509] WARNING: at kernel/softirq.c:136 local_bh_enable+0x37/0x81()
...
[   27.782520]  [<c0264755>] netif_nit_deliver+0x5b/0x75
[   27.782590]  [<c02bba83>] __vlan_hwaccel_rx+0x79/0x162
[   27.782664]  [<f8851c1d>] atl1_intr+0x9a9/0xa7c [atl1]
[   27.782738]  [<c0155b17>] handle_IRQ_event+0x23/0x51
[   27.782808]  [<c015692e>] handle_edge_irq+0xc2/0x102
[   27.782878]  [<c0105fd5>] do_IRQ+0x4d/0x64

Split hardware accelerated VLAN reception into two parts to fix this:

- __vlan_hwaccel_rx just stores the VLAN TCI and performs the VLAN
  device lookup, then calls netif_receive_skb()/netif_rx()

- vlan_hwaccel_do_receive(), which is invoked by netif_receive_skb()
  in softirq context, performs the real reception and delivery to
  packet sockets.
Reported-and-tested-by: NRamon Casellas <ramon.casellas@cttc.es>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch gets about 1.25% back on tbench regression.

My change to NAPI for multiqueue support changed the time limit on
network receive processing.  Under sustained loads like tbench, this
can cause the receiver to reschedule prematurely. 
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To make testing of the network namespace simpler allow
the network namespace code and the sysfs code to be
compiled and run at the same time.  To do this only
virtual devices are allowed in the additional network
namespaces and those virtual devices are not placed
in the kobject tree.

Since virtual devices don't actually do anything interesting
hardware wise that needs device management there should
be no loss in keeping them out of the kobject tree and
by implication sysfs.  The gain in ease of testing
and code coverage should be significant.

Changelog:

v2: As pointed out by Benjamin Thery it only makes sense to call
    device_rename in the initial network namespace for now.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NBenjamin Thery <benjamin.thery@bull.net>
Tested-by: NSerge Hallyn <serue@us.ibm.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

My change

    commit e2a6b852
    net: Enable TSO if supported by at least one device

didn't do what was intended because the netdev_compute_features
function was designed for conjunctions.  So what happened was that
it would simply take the TSO status of the last constituent device.

This patch extends it to support both conjunctions and disjunctions
under the new name of netdev_increment_features.

It also adds a new function netdev_fix_features which does the
sanity checking that usually occurs upon registration.  This ensures
that the computation doesn't result in an illegal combination
since this checking is absent when the change is initiated via
ethtool.

The two users of netdev_compute_features have been converted.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If changename notifier returns an error code, it gets incorrectly
cleared during rollback so the error is never returned to the user.
Found while testing similar code for MTU changes.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some code here depends on CONFIG_KMOD to not try to load
protocol modules or similar, replace by CONFIG_MODULES
where more than just request_module depends on CONFIG_KMOD
and and also use try_then_request_module in ebtables.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Benjamin Thery tracked down a bug that explains many instances
of the error

unregister_netdevice: waiting for %s to become free. Usage count = %d

It turns out that netdev_run_todo can dead-lock with itself if
a second instance of it is run in a thread that will then free
a reference to the device waited on by the first instance.

The problem is really quite silly.  We were trying to create
parallelism where none was required.  As netdev_run_todo always
follows a RTNL section, and that todo tasks can only be added
with the RTNL held, by definition you should only need to wait
for the very ones that you've added and be done with it.

There is no need for a second mutex or spinlock.

This is exactly what the following patch does.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jesper Dangaard Brouer <hawk@comx.dk> reported a bug when setting a VLAN
device down that is in promiscous mode:

When the VLAN device is set down, the promiscous count on the real
device is decremented by one by vlan_dev_stop(). When removing the
promiscous flag from the VLAN device afterwards, the promiscous
count on the real device is decremented a second time by the
vlan_change_rx_flags() callback.

The root cause for this is that the ->change_rx_flags() callback is
invoked while the device is down. The synchronization is meant to mirror
the behaviour of the ->set_rx_mode callbacks, meaning the ->open function
is responsible for doing a full sync on open, the ->close() function is
responsible for doing full cleanup on ->stop() and ->change_rx_flags()
is meant to do incremental changes while the device is UP.

Only invoke ->change_rx_flags() while the device is UP to provide the
intended behaviour.
Tested-by: NJesper Dangaard Brouer <jdb@comx.dk>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add more docbook comments to network device functions and cleanup
the comments.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dev_change_name and netdev_drivername should use const char on
parameters that are read-only input values. The strcpy to newname is
not needed since newname is not used later in function.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes the potentially allocated ifalias when the (new) given alias is empty.

E.g. when setting

echo "" > /sys/class/net/eth0/ifalias
Signed-off-by: NOliver Hartkopp <oliver@hartkopp.net>
Acked-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch add support for keeping an additional character alias
associated with an network interface. This is useful for maintaining
the SNMP ifAlias value which is a user defined value. Routers use this
to hold information like which circuit or line it is connected to. It
is just an arbitrary text label on the network device.

There are two exposed interfaces with this patch, the value can be
read/written either via netlink or sysfs.

This could be maintained just by the snmp daemon, but it is more
generally useful for other management tools, and the kernel is good
place to act as an agreed upon interface to store it.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently simple_tx_hash is hashing inside of udp fragments.  As a result
packets are getting getting sent to all queues when they shouldn't be.
This causes a serious performance regression which can be seen by sending
UDP frames larger than mtu on multiqueue devices.  This change will make
it so that fragments are hashed only as IP datagrams w/o any protocol
information.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As it stands users of netdev_compute_features (e.g., bridges/bonding)
will only enable TSO if all consituent devices support it.  This
is unnecessarily pessimistic since even on devices that do not
support hardware TSO and SG, emulated TSO still performs to a par
with TSO off.

This patch enables TSO if at least on constituent device supports
it in hardware.

The direct beneficiaries will be virtualisation that uses bridging
since this means that TSO will always be enabled for communication
from the host to the guests.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net_tx_action() can skip __QDISC_STATE_SCHED bit clearing while qdisc
is neither ran nor rescheduled, which may cause endless loop in
dev_deactivate().
Reported-by: NDenys Fedoryshchenko <denys@visp.net.lb>
Tested-by: NDenys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If dev_deactivate() is trying to quiesce the queue, it
is theoretically possible for another cpu to livelock
trying to process that queue.  This happens because
dev_deactivate() grabs the queue spinlock as it checks
the queue state, whereas net_tx_action() does a trylock
and reschedules the qdisc if it hits the lock.

This breaks the livelock by adding a check on
__QDISC_STATE_DEACTIVATED to net_tx_action() when
the trylock fails.

Based upon feedback from Herbert Xu and Jarek Poplawski.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Noticed by Jarek Poplawski.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change handling of the __QDISC_STATE_SCHED flag in net_tx_action() to
enable proper control in dev_deactivate(). Now, if this flag is seen
as unset under root_lock means a qdisc can't be netif_scheduled.
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This new state lets dev_deactivate() mark a qdisc as having been
deactivated.

dev_queue_xmit() and ing_filter() check for this bit and do not
try to process the qdisc if the bit is set.

dev_deactivate() polls the qdisc after setting the bit, waiting
for both __QDISC_STATE_RUNNING and __QDISC_STATE_SCHED to clear.

This isn't perfect yet, but subsequent changesets will make it so.
This part is just one piece of the puzzle.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a packet_type specifies an active slave to bonding and not just any
interface, allow it to receive frames that came in on that interface.
Signed-off-by: NJoe Eykholt <jre@nuovasystems.com>
Signed-off-by: NJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Allow a packet_type that specifies the exact device to receive
even on an inactive bonding slave devices.  This is important for some
L2 protocols such as LLDP and FCoE.  This can eventually be used
for the bonding special cases as well.
Signed-off-by: NJoe Eykholt <jre@nuovasystems.com>
Signed-off-by: NJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Otherwise subsequent changes need multiple return values.
Signed-off-by: NJoe Eykholt <jre@nuovasystems.com>
Signed-off-by: NJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Patrick McHardy <kaber@trash.net> noticed that it would be nice to
handle NET_XMIT_BYPASS by NET_XMIT_SUCCESS with an internal qdisc flag
__NET_XMIT_BYPASS and to remove the mapping from dev_queue_xmit().

David Miller <davem@davemloft.net> spotted a serious bug in the first
version of this patch.
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Avoid the overhead of atomic increment/decrement on each received packet.
This helps performance of non-NAPI devices (like loopback).
Use cleanup function to walk queue on each cpu and clean out any
left over packets.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a netdevice does not support hardware GSO, allowing the stack to
use GSO anyway and then splitting the GSO skb into MSS-sized pieces
as it is handed to the netdevice for transmitting is likely still
a win as far as throughput and/or CPU usage are concerned, since it
reduces the number of trips through the output path.

This patch enables the use of GSO on any netdevice that supports SG.
If a GSO skb is then sent to a netdevice that supports SG but does not
support hardware GSO, net/core/dev.c:dev_hard_start_xmit() will take
care of doing the necessary GSO segmentation in software.
Signed-off-by: NLennert Buytenhek <buytenh@marvell.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon a bug report by Jeff Kirsher.

Don't use qdisc_root_lock() in these cases as the root
qdisc could have been changed, and we'd thus lock the
wrong object.

Tested by Emil S Tantilov who confirms that this seems
to fix the problem.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When support for multiple TX queues were added, the
netif_tx_lock() routines we converted to iterate over
all TX queues and grab each queue's spinlock.

This causes heartburn for lockdep and it's not a healthy
thing to do with lots of TX queues anyways.

So modify this to use a top-level lock and a "frozen"
state for the individual TX queues.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bug report from Steven Jan Springl:

	Issuing the following command causes a kernel oops:
		tc qdisc add dev eth0 handle ffff: ingress

The problem mostly stems from all of the special case handling of
ingress qdiscs.

So, to fix this, do the grafting operation the same way we do for TX
qdiscs.  Which means that dev_activate() and dev_deactivate() now do
the "qdisc_sleeping <--> qdisc" transitions on dev->rx_queue too.

Future simplifications are possible now, mainly because it is
impossible for dev_queue->{qdisc,qdisc_sleeping} to be NULL.  There
are NULL checks all over to handle the ingress qdisc special case
that used to exist before this commit.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Removes legacy reinvent-the-wheel type thing. The generic
machinery integrates much better to automated debugging aids
such as kerneloops.org (and others), and is unambiguous due to
better naming. Non-intuively BUG_TRAP() is actually equal to
WARN_ON() rather than BUG_ON() though some might actually be
promoted to BUG_ON() but I left that to future.

I could make at least one BUILD_BUG_ON conversion.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It isn't helping anything and we aren't going to be able to change all
the drivers that do queue wakeups in strange situations.

Just letting a noop_qdisc get scheduled will work because when
qdisc_run() executes via net_tx_work() it will simply find no packets
pending when it makes the ->dequeue() call in qdisc_restart.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>