netdev_wait_allrefs() waits that all references to a device vanishes.

It currently uses a _very_ pessimistic 250 ms delay between each probe.
Some users reported that no more than 4 devices can be dismantled per
second, this is a pretty serious problem for some setups.

Most of the time, a refcount is about to be released by an RCU callback,
that is still in flight because rollback_registered_many() uses a
synchronize_rcu() call instead of rcu_barrier(). Problem is visible if
number of online cpus is one, because synchronize_rcu() is then a no op.

time to remove 50 ipip tunnels on a UP machine :

before patch : real 11.910s
after patch : real 1.250s
Reported-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Reported-by: NOctavian Purdila <opurdila@ixiacom.com>
Reported-by: NBenjamin LaHaise <bcrl@kvack.org>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The patch: "gro: fix different skb headrooms" in its part:
"2) allocate a minimal skb for head of frag_list" is buggy. The copied
skb has p->data set at the ip header at the moment, and skb_gro_offset
is the length of ip + tcp headers. So, after the change the length of
mac header is skipped. Later skb_set_mac_header() sets it into the
NET_SKB_PAD area (if it's long enough) and ip header is misaligned at
NET_SKB_PAD + NET_IP_ALIGN offset. There is no reason to assume the
original skb was wrongly allocated, so let's copy it as it was.

bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=16626
fixes commit: 3d3be433Reported-by: NPlamen Petrov <pvp-lsts@fs.uni-ruse.bg>
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Tested-by: NPlamen Petrov <pvp-lsts@fs.uni-ruse.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a net device is implementing the select_queue callback and is part of
a bridge, frames coming from the bridge already have a tx queue associated
to the socket (introduced in commit a4ee3ce3,
"net: Use sk_tx_queue_mapping for connected sockets"). The call to
sk_tx_queue_get will then return the tx queue used by the bridge instead
of calling the select_queue callback.

In case of mac80211 this broke QoS which is implemented by using the
select_queue callback. Furthermore it introduced problems with rt2x00
because frames with the same TID and RA sometimes appeared on different
tx queues which the hw cannot handle correctly.

Fix this by always calling select_queue first if it is available and only
afterwards use the socket tx queue mapping.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes a lockdep warning:

[  516.287584] =========================================================
[  516.288386] [ INFO: possible irq lock inversion dependency detected ]
[  516.288386] 2.6.35b #7
[  516.288386] ---------------------------------------------------------
[  516.288386] swapper/0 just changed the state of lock:
[  516.288386]  (&qdisc_tx_lock){+.-...}, at: [<c12eacda>] est_timer+0x62/0x1b4
[  516.288386] but this lock took another, SOFTIRQ-unsafe lock in the past:
[  516.288386]  (est_tree_lock){+.+...}
[  516.288386] 
[  516.288386] and interrupts could create inverse lock ordering between them.
...

So, est_tree_lock needs BH protection because it's taken by
qdisc_tx_lock, which is used both in BH and process contexts.
(Full warning with this patch at netdev, 02 Sep 2010.)

Fixes commit: ae638c47
("pkt_sched: gen_estimator: add a new lock")
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Packets entering GRO might have different headrooms, even for a given
flow (because of implementation details in drivers, like copybreak).
We cant force drivers to deliver packets with a fixed headroom.

1) fix skb_segment()

skb_segment() makes the false assumption headrooms of fragments are same
than the head. When CHECKSUM_PARTIAL is used, this can give csum_start
errors, and crash later in skb_copy_and_csum_dev()

2) allocate a minimal skb for head of frag_list

skb_gro_receive() uses netdev_alloc_skb(headroom + skb_gro_offset(p)) to
allocate a fresh skb. This adds NET_SKB_PAD to a padding already
provided by netdevice, depending on various things, like copybreak.

Use alloc_skb() to allocate an exact padding, to reduce cache line
needs:
NET_SKB_PAD + NET_IP_ALIGN

bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=16626

Many thanks to Plamen Petrov, testing many debugging patches !
With help of Jarek Poplawski.
Reported-by: NPlamen Petrov <pvp-lsts@fs.uni-ruse.bg>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
CC: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

>Xin Xiaohui wrote:
> I looked into the code dev_gro_receive(), found the code here:
> if the frags[0] is pulled to 0, then the page will be released,
> and memmove() frags left.
> Is that right? I'm not sure if memmove do right or not, but
> frags[0].size is never set after memove at least. what I think
> a simple way is not to do anything if we found frags[0].size == 0.
> The patch is as followed.
...

This version of the patch fixes the bug directly in memmove.
Reported-by: N"Xin, Xiaohui" <xiaohui.xin@intel.com>
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Although netif_rx() isn't expected to be called in process context with
preemption enabled, it'd better handle this case. And this is why get_cpu()
is used in the non-RPS #ifdef branch. If tree RCU is selected,
rcu_read_lock() won't disable preemption, so preempt_disable() should be
called explictly.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The netpoll_rx_on() check in __napi_gro_receive() skips part of the
"common" GRO_NORMAL path, especially "pull:" in dev_gro_receive(),
where at least eth header should be copied for entirely paged skbs.
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>

This reverts commit 15e83ed7.

As explained by Johannes Berg, the optimization made here is
invalid.  Or, at best, incomplete.

Not only destructor invocation, but conntract entry releasing
must be executed outside of hw IRQ context.

So just checking "skb->destructor" is insufficient.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit ab95bfe0 replaces bridge and macvlan
hooks in __netif_receive_skb(), so dev.c doesn't need to include their headers.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If user misconfigures ingress and causes a redirection loop, don't
overwhelm the log.  This is also a error case so make it unlikely.
Found by inspection, luckily not in real system.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

[ Fix unused local variable build warnings. -DaveM ]
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With conn-track zones and probably with different network
namespaces, the netfilter logic needs to be re-calculated
on packet receive.  If the netfilter logic is not reset,
it will not be recalculated properly.  This patch adds
the nf_reset logic to dev_forward_skb.
Signed-off-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move frags[] at the end of struct skb_shared_info, and make
pskb_expand_head() copy only the used part of it instead of whole array.

This should avoid kmemcheck warnings and speedup pskb_expand_head() as
well, avoiding a lot of cache misses.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add addr_assign_type to struct net_device and expose it via sysfs.
This new attribute has the purpose of giving user-space the ability to
distinguish between different assignment types of MAC addresses.

For example user-space can treat NICs with randomly generated MAC
addresses differently than NICs that have permanent (locally assigned)
MAC addresses.
For the former udev could write a persistent net rule by matching the
device path instead of the MAC address.
There's also the case of devices that 'steal' MAC addresses from slave
devices. In which it is also be beneficial for user-space to be aware
of the fact.

This patch also introduces a helper function to assist adoption of
drivers that generate MAC addresses randomly.
Signed-off-by: NStefan Assmann <sassmann@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It should only be adjusted if ip_summed == CHECKSUM_PARTIAL.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make pskb_expand_head() check ip_summed to make sure csum_start is really
csum_start and not csum before adjusting it.

This fixes a bug I encountered using a Sun Quad-Fast Ethernet card and VLANs.
On my configuration, the sunhme driver produces skbs with differing amounts
of headroom on receive depending on the packet size.  See line 2030 of
drivers/net/sunhme.c; packets smaller than RX_COPY_THRESHOLD have 52 bytes
of headroom but packets larger than that cutoff have only 20 bytes.

When these packets reach the VLAN driver, vlan_check_reorder_header()
calls skb_cow(), which, if the packet has less than NET_SKB_PAD (== 32) bytes
of headroom, uses pskb_expand_head() to make more.

Then, pskb_expand_head() needs to adjust a lot of offsets into the skb,
including csum_start.  Since csum_start is a union with csum, if the packet
has a valid csum value this will corrupt it, which was the effect I observed.
The sunhme hardware computes receive checksums, so the skbs would be created
by the driver with ip_summed == CHECKSUM_COMPLETE and a valid csum field, and
then pskb_expand_head() would corrupt the csum field, leading to an "hw csum
error" message later on, for example in icmp_rcv() for pings larger than the
sunhme RX_COPY_THRESHOLD.

On the basis of the comment at the beginning of include/linux/skbuff.h,
I believe that the csum_start skb field is only meaningful if ip_csummed is
CSUM_PARTIAL, so this patch makes pskb_expand_head() adjust it only in that
case to avoid corrupting a valid csum value.

Please see my more in-depth disucssion of tracking down this bug for
more details if you like:

http://puellavulnerata.livejournal.com/112186.html
http://puellavulnerata.livejournal.com/112567.html
http://puellavulnerata.livejournal.com/112891.html
http://puellavulnerata.livejournal.com/113096.html
http://puellavulnerata.livejournal.com/113591.html

I am not subscribed to this list, so please CC me on replies.
Signed-off-by: NAndrea Shepard <andrea@persephoneslair.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

	Patch to add -EAGAIN error to dropwatch netlink message handling code.
-EAGAIN will be returned anytime userspace attempts to transition the state of
the drop monitor service to a state that its already in.  That allows user space
to detect this condition, so it doesn't wait for a success ACK that will never
arrive.  Tested successfully by me
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use modern this_cpu_xxx() api, saving few bytes on x86
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since struct netdev_queue tx_bytes/tx_packets/tx_dropped are already
protected by _xmit_lock, its easy to convert these fields to u64 instead
of unsigned long.
This completes 64bit stats for devices using them (vlan, macvlan, ...)

Strictly, we could avoid the locking in dev_txq_stats_fold() on 64bit
arches, but its slow path and we prefer keep it simple.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a new networking option to allow hardware time stamps
from PHY devices. When enabled, likely candidates among incoming and
outgoing network packets are offered to the PHY driver for possible
time stamping. When accepted by the PHY driver, incoming packets are
deferred for later delivery by the driver.

The patch also adds phylib driver methods for the SIOCSHWTSTAMP ioctl
and callbacks for transmit and receive time stamping. Drivers may
optionally implement these functions.
Signed-off-by: NRichard Cochran <richard.cochran@omicron.at>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix problem in reading the tx_queue recorded in a socket.  In
dev_pick_tx, the TX queue is read by doing a check with
sk_tx_queue_recorded on the socket, followed by a sk_tx_queue_get.
The problem is that there is not mutual exclusion across these
calls in the socket so it it is possible that the queue in the
sock can be invalidated after sk_tx_queue_recorded is called so
that sk_tx_queue get returns -1, which sets 65535 in queue_index
and thus dev_pick_tx returns 65536 which is a bogus queue and
can cause crash in dev_queue_xmit.

We fix this by only calling sk_tx_queue_get which does the proper
checks.  The interface is that sk_tx_queue_get returns the TX queue
if the sock argument is non-NULL and TX queue is recorded, else it
returns -1.  sk_tx_queue_recorded is no longer used so it can be
completely removed.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When configuring DMVPN (GRE + openNHRP) and a GRE remote
address is configured a kernel Oops is observed.  The
obserseved Oops is caused by a NULL header_ops pointer
(neigh->dev->header_ops) in neigh_update_hhs() when

void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *)
= neigh->dev->header_ops->cache_update;

is executed.  The dev associated with the NULL header_ops is
the GRE interface.  This patch guards against the
possibility that header_ops is NULL.

This Oops was first observed in kernel version 2.6.26.8.
Signed-off-by: NDoug Kehn <rdkehn@yahoo.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit fc6055a5 (net: Introduce skb_orphan_try()) added early
orphaning of skbs.

This unfortunately added a performance regression in skb_tx_hash() in
case of stacked devices (bonding, vlans, ...)

Since skb->sk is now NULL, we cannot access sk->sk_hash anymore to
spread tx packets to multiple NIC queues on multiqueue devices.

skb_tx_hash() in this case only uses skb->protocol, same value for all
flows.

skb_orphan_try() can copy sk->sk_hash into skb->rxhash and skb_tx_hash()
can use this saved sk_hash value to compute its internal hash value.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Avoid two extra instructions in sock_free(), to reload
skb->truesize and skb->sk
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CodingStyle cleanups

EXPORT_SYMBOL should immediately follow the symbol declaration.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Document that dev_get_stats() returns the same stats pointer it was
given.  Remove const qualification from the returned pointer since the
caller may do what it likes with that structure.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit be1f3c2c "net: Enable 64-bit
net device statistics on 32-bit architectures" I redefined struct
net_device_stats so that it could be used in a union with struct
rtnl_link_stats64, avoiding the need for explicit copying or
conversion between the two.  However, this is unsafe because there is
no locking required and no lock consistently held around calls to
dev_get_stats() and use of the statistics structure it returns.

In commit 28172739 "net: fix 64 bit
counters on 32 bit arches" Eric Dumazet dealt with that problem by
requiring callers of dev_get_stats() to provide storage for the
result.  This means that the net_device::stats64 field and the padding
in struct net_device_stats are now redundant, so remove them.

Update the comment on net_device_ops::ndo_get_stats64 to reflect its
new usage.

Change dev_txq_stats_fold() to use struct rtnl_link_stats64, since
that is what all its callers are really using and it is no longer
going to be compatible with struct net_device_stats.

Eric Dumazet suggested the separate function for the structure
conversion.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is a small possibility that a reader gets incorrect values on 32
bit arches. SNMP applications could catch incorrect counters when a
32bit high part is changed by another stats consumer/provider.

One way to solve this is to add a rtnl_link_stats64 param to all
ndo_get_stats64() methods, and also add such a parameter to
dev_get_stats().

Rule is that we are not allowed to use dev->stats64 as a temporary
storage for 64bit stats, but a caller provided area (usually on stack)

Old drivers (only providing get_stats() method) need no changes.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reduces an x86 defconfig text and data ~2k.
text is smaller, data is larger.

$ size vmlinux*
   text	   data	    bss	    dec	    hex	filename
7198862	 720112	1366288	9285262	 8dae8e	vmlinux
7205273	 716016	1366288	9287577	 8db799	vmlinux.device_h

Uses %pV and struct va_format
Format arguments are verified before printk
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reducing real_num_queues needs to flush the qdisc otherwise
skbs with queue_mappings greater then real_num_tx_queues can
be sent to the underlying driver.

The flow for this is,

dev_queue_xmit()
	dev_pick_tx()
		skb_tx_hash()  => hash using real_num_tx_queues
		skb_set_queue_mapping()
	...
	qdisc_enqueue_root() => enqueue skb on txq from hash
...
dev->real_num_tx_queues -= n
...
sch_direct_xmit()
	dev_hard_start_xmit()
		ndo_start_xmit(skb,dev) => skb queue set with old hash

skbs are enqueued on the qdisc with skb->queue_mapping set
0 < queue_mappings < real_num_tx_queues.  When the driver
decreases real_num_tx_queues skb's may be dequeued from the
qdisc with a queue_mapping greater then real_num_tx_queues.

This fixes a case in ixgbe where this was occurring with DCB
and FCoE. Because the driver is using queue_mapping to map
skbs to tx descriptor rings we can potentially map skbs to
rings that no longer exist.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Tested-by: NRoss Brattain <ross.b.brattain@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Many NICs use an indirection table to map an RX flow hash value to one
of an arbitrary number of queues (not necessarily a power of 2).  It
can be useful to remove some queues from this indirection table so
that they are only used for flows that are specifically filtered
there.  It may also be useful to weight the mapping to account for
user processes with the same CPU-affinity as the RX interrupts.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ethtool_op_set_flags() does not check for unsupported flags, and has
no way of doing so.  This means it is not suitable for use as a
default implementation of ethtool_ops::set_flags.

Add a 'supported' parameter specifying the flags that the driver and
hardware support, validate the requested flags against this, and
change all current callers to pass this parameter.

Change some other trivial implementations of ethtool_ops::set_flags to
call ethtool_op_set_flags().
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Reviewed-by: NStanislaw Gruszka <sgruszka@redhat.com>
Acked-by: NJeff Garzik <jgarzik@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is only noticed by people that are not doing everything correct in
the first place.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct ethtool_rxnfc was originally defined in 2.6.27 for the
ETHTOOL_{G,S}RXFH command with only the cmd, flow_type and data
fields.  It was then extended in 2.6.30 to support various additional
commands.  These commands should have been defined to use a new
structure, but it is too late to change that now.

Since user-space may still be using the old structure definition
for the ETHTOOL_{G,S}RXFH commands, and since they do not need the
additional fields, only copy the originally defined fields to and
from user-space.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Cc: stable@kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On a 32-bit machine, info.rule_cnt >= 0x40000000 leads to integer
overflow and the buffer may be smaller than needed.  Since
ETHTOOL_GRXCLSRLALL is unprivileged, this can presumably be used for at
least denial of service.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Cc: stable@kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

use this_cpu_ptr(p) instead of per_cpu_ptr(p, smp_processor_id())
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>