RCU api had been completed and rcu_access_pointer() or
rcu_dereference_protected() are better than generic
rcu_dereference_raw()
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove the artificial HZ latency on arp resolution.

Instead of firing a timer in one jiffy (up to 10 ms if HZ=100), lets
send the ARP message immediately.

Before patch :

# arp -d 192.168.20.108 ; ping -c 3 192.168.20.108
PING 192.168.20.108 (192.168.20.108) 56(84) bytes of data.
64 bytes from 192.168.20.108: icmp_seq=1 ttl=64 time=9.91 ms
64 bytes from 192.168.20.108: icmp_seq=2 ttl=64 time=0.065 ms
64 bytes from 192.168.20.108: icmp_seq=3 ttl=64 time=0.061 ms

After patch :

$ arp -d 192.168.20.108 ; ping -c 3 192.168.20.108
PING 192.168.20.108 (192.168.20.108) 56(84) bytes of data.
64 bytes from 192.168.20.108: icmp_seq=1 ttl=64 time=0.152 ms
64 bytes from 192.168.20.108: icmp_seq=2 ttl=64 time=0.064 ms
64 bytes from 192.168.20.108: icmp_seq=3 ttl=64 time=0.074 ms
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dev->real_num_tx_queues is correctly set already in alloc_netdev_mqs.
Signed-off-by: NJiri Pirko <jpirko@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Followup of commit f2c31e32 (fix NULL dereferences in
check_peer_redir()).

We need to make sure dst neighbour doesnt change in dst_ifdown().

Fix some sparse errors.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation.  So the periodic
regeneration and 8-bit counter have been removed.  We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.
Reported-by: NDan Kaminsky <dan@doxpara.com>
Tested-by: NWilly Tarreau <w@1wt.eu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// </smpl>
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since skb_copy_bits() is called from assembly, add a fat comment to make
clear we should think twice before changing its prototype.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pktgen attempts to transmit shared skbs to net devices, which can't be used by
some drivers as they keep state information in skbs.  This patch adds a flag
marking drivers as being able to handle shared skbs in their tx path.  Drivers
are defaulted to being unable to do so, but calling ether_setup enables this
flag, as 90% of the drivers calling ether_setup touch real hardware and can
handle shared skbs.  A subsequent patch will audit drivers to ensure that the
flag is set properly
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Reported-by: NJiri Pirko <jpirko@redhat.com>
CC: Robert Olsson <robert.olsson@its.uu.se>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Alexey Dobriyan <adobriyan@gmail.com>
CC: David S. Miller <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: NArun Sharma <asharma@fb.com>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

No need to use int, its uses are boolean.
May save a few bytes one day.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As reported by Ben Greer and Froncois Romieu. The code path in
the netif_carrier code leads it to try and disable
a late workqueue to reenable it immediately
netif_carrier_on
-> linkwatch_fire_event
   -> linkwatch_schedule_work
      -> cancel_delayed_work
         -> del_timer_sync

If __cancel_delayed_work is used instead then there is no
problem of waiting for running linkwatch_event.

There is a race between linkwatch_event running re-scheduling
but it is harmless to schedule an extra scan of the linkwatch queue.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some drivers (ab)use the ethtool_ops::get_regs operation to expose
only a hardware revision ID.  Commit
a77f5db3 ('ethtool: Allocate register
dump buffer with vmalloc()') had the side-effect of breaking these, as
vmalloc() returns a null pointer for size=0 whereas kmalloc() did not.

For backward-compatibility, allow zero-length dumps again.
Reported-by: NKalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Cc: stable@kernel.org [2.6.37+]
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are two problems:
1) "n" was allocated with alloc_skb() so we should free it with
   kfree_skb() instead of regular kfree().
2) We return the freed pointer instead of NULL.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dst_{get,set}_neighbour()
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This will get us closer to being able to do "neigh stuff"
completely independent of the underlying dst_entry for
protocols (ipv4/ipv6) that wish to do so.

We will also be able to make dst entries neigh-less.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is always dev_queue_xmit().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It's just taking on one of two possible values, either
neigh_ops->output or dev_queue_xmit().  And this is purely depending
upon whether nud_state has NUD_CONNECTED set or not.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It's always dev_queue_xmit().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that hh_cache entries are embedded inside of neighbour
entries, their lifetimes and accesses are now synchronous
to that of the encompassing neighbour object.

Therefore we don't need to hook up the blackhole op to
hh_output on destroy.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The same information and more can be obtained by using ethtool
with ETHTOOL_GFEATURES.
Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is not used anywhere except net/core/dev.c now.
Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

vlan_features contains features inherited from underlying device.
NETIF_SOFT_FEATURES are not inherited but belong to the vlan device
itself (ensured in vlan_dev_fix_features()).
Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that there is a one-to-one correspondance between neighbour
and hh_cache entries, we no longer need:

1) dynamic allocation
2) attachment to dst->hh
3) refcounting

Initialization of the hh_cache entry is indicated by hh_len
being non-zero, and such initialization is always done with
the neighbour's lock held as a writer.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This never, ever, happens.

Neighbour entries are always tied to one address family, and therefore
one set of dst_ops, and therefore one dst_ops->protocol "hh_type"
value.

This capability was blindly imported by Alexey Kuznetsov when he wrote
the neighbour layer.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

We need to make sure the multiplier is odd.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

And mask the hash function result by simply shifting
down the "->hash_shift" most significant bits.

Currently which bits we use is arbitrary since jhash
produces entropy evenly across the whole hash function
result.

But soon we'll be using universal hashing functions,
and in those cases more entropy exists in the higher
bits than the lower bits, because they use multiplies.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch clears tx zero-copy flag as needed.
Signed-off-by: NShirley Ma <xma@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds userspace buffers support in skb shared info. A new
struct skb_ubuf_info is needed to maintain the userspace buffers
argument and index, a callback is used to notify userspace to release
the buffers once lower device has done DMA (Last reference to that skb
has gone).

If there is any userspace apps to reference these userspace buffers,
then these userspaces buffers will be copied into kernel. This way we
can prevent userspace apps from holding these userspace buffers too long.

Use destructor_arg to point to the userspace buffer info; a new tx flags
SKBTX_DEV_ZEROCOPY is added for zero-copy buffer check.
Signed-off-by: NShirley Ma <xma@...ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Just add GSO to vlan_features initialization, and update comments.

When we set offload features, vlan_dev_fix_features() will do more check.
In vlan_dev_fix_features(), final features is decided by
features of real device and vlan_features of real device.
Signed-off-by: NShan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NLauro Ramos Venancio <lauro.venancio@openbossa.org>
Signed-off-by: NAloisio Almeida Jr <aloisio.almeida@openbossa.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Too trivial to live.

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

Unused symbols waste space.

Commit 0e34e931
"(netpoll: add generic support for bridge and bonding devices)"
added the symbol more than a year ago with the promise of "future use".

Because it is so far unused, remove it for now.
It can be easily readded if or when it actually needs to be used.

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

IPV6, unlike IPV4, doesn't have a routing cache.

Routing table entries, as well as clones made in response
to route lookup requests, all live in the same table.  And
all of these things are together collected in the destination
cache table for ipv6.

This means that routing table entries count against the garbage
collection limits, even though such entries cannot ever be reclaimed
and are added explicitly by the administrator (rather than being
created in response to lookups).

Therefore it makes no sense to count ipv6 routing table entries
against the GC limits.

Add a DST_NOCOUNT destination cache entry flag, and skip the counting
if it is set.  Use this flag bit in ipv6 when adding routing table
entries.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a change sequence counter to each net namespace
which is bumped whenever a netdevice is added or removed from
the list. If such a change occurred while a link dump took place,
the dump will have the NLM_F_DUMP_INTR flag set in the first
message which has been interrupted and in all subsequent messages
of the same dump.

Note that links may still be modified or renamed while a dump is
taking place but we can guarantee for userspace to receive a
complete list of links and not miss any.

Testing:
I have added 500 VLAN netdevices to make sure the dump is split
over multiple messages. Then while continuously dumping links in
one process I also continuously deleted and re-added a dummy
netdevice in another process. Multiple dumps per seconds have
had the NLM_F_DUMP_INTR flag set.

I guess we can wait for Johannes patch to hit net-next via the
wireless tree.  I just wanted to give this some testing right away.
Signed-off-by: NThomas Graf <tgraf@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are enough instances of this:

    iph->frag_off & htons(IP_MF | IP_OFFSET)

that a helper function is probably warranted.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds 2 tracepoints to get a status of a socket receive queue
and related parameter.

One tracepoint is added to sock_queue_rcv_skb. It records rcvbuf size
and its usage. The other tracepoint is added to __sk_mem_schedule and
it records limitations of memory for sockets and current usage.

By using these tracepoints we're able to know detailed reason why kernel
drop the packet.
Signed-off-by: NSatoru Moriya <satoru.moriya@hds.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a tracepoint to __udp_queue_rcv_skb to get the
return value of ip_queue_rcv_skb. It indicates why kernel drops
a packet at this point.

ip_queue_rcv_skb returns following values in the packet drop case:

rcvbuf is full                 : -ENOMEM
sk_filter returns error        : -EINVAL, -EACCESS, -ENOMEM, etc.
__sk_mem_schedule returns error: -ENOBUF
Signed-off-by: NSatoru Moriya <satoru.moriya@hds.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ethernet MAC drivers based on phylib (but not using NAPI) can
enable hardware time stamping in phy devices by calling netif_rx()
conditionally based on a call to skb_defer_rx_timestamp().

This commit exports that function so that drivers calling it may
be compiled as modules.
Signed-off-by: NRichard Cochran <richard.cochran@omicron.at>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The network stack provides the function, skb_clone_tx_timestamp().
Ethernet MAC drivers can call this via the transmit time stamping
hook, skb_tx_timestamp(). This commit exports the clone function so
that drivers using it can be compiled as modules.
Signed-off-by: NRichard Cochran <richard.cochran@omicron.at>
Signed-off-by: NDavid S. Miller <davem@conan.davemloft.net>