Now ipv6_gso_segment() is stackable, its relatively easy to
implement GSO/TSO support for SIT tunnels

Performance results, when segmentation is done after tunnel
device (as no NIC is yet enabled for TSO SIT support) :

Before patch :

lpq84:~# ./netperf -H 2002:af6:1153:: -Cc
MIGRATED TCP STREAM TEST from ::0 (::) port 0 AF_INET6 to 2002:af6:1153:: () port 0 AF_INET6
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  16384  16384    10.00      3168.31   4.81     4.64     2.988   2.877

After patch :

lpq84:~# ./netperf -H 2002:af6:1153:: -Cc
MIGRATED TCP STREAM TEST from ::0 (::) port 0 AF_INET6 to 2002:af6:1153:: () port 0 AF_INET6
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  16384  16384    10.00      5525.00   7.76     5.17     2.763   1.840
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Cc: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net_get_random_once is a new macro which handles the initialization
of secret keys. It is possible to call it in the fast path. Only the
initialization depends on the spinlock and is rather slow. Otherwise
it should get used just before the key is used to delay the entropy
extration as late as possible to get better randomness. It returns true
if the key got initialized.

The usage of static_keys for net_get_random_once is a bit uncommon so
it needs some further explanation why this actually works:

=== In the simple non-HAVE_JUMP_LABEL case we actually have ===
no constrains to use static_key_(true|false) on keys initialized with
STATIC_KEY_INIT_(FALSE|TRUE). So this path just expands in favor of
the likely case that the initialization is already done. The key is
initialized like this:

___done_key = { .enabled = ATOMIC_INIT(0) }

The check

                if (!static_key_true(&___done_key))                     \

expands into (pseudo code)

                if (!likely(___done_key > 0))

, so we take the fast path as soon as ___done_key is increased from the
helper function.

=== If HAVE_JUMP_LABELs are available this depends ===
on patching of jumps into the prepared NOPs, which is done in
jump_label_init at boot-up time (from start_kernel). It is forbidden
and dangerous to use net_get_random_once in functions which are called
before that!

At compilation time NOPs are generated at the call sites of
net_get_random_once. E.g. net/ipv6/inet6_hashtable.c:inet6_ehashfn (we
need to call net_get_random_once two times in inet6_ehashfn, so two NOPs):

      71:       0f 1f 44 00 00          nopl   0x0(%rax,%rax,1)
      76:       0f 1f 44 00 00          nopl   0x0(%rax,%rax,1)

Both will be patched to the actual jumps to the end of the function to
call __net_get_random_once at boot time as explained above.

arch_static_branch is optimized and inlined for false as return value and
actually also returns false in case the NOP is placed in the instruction
stream. So in the fast case we get a "return false". But because we
initialize ___done_key with (enabled != (entries & 1)) this call-site
will get patched up at boot thus returning true. The final check looks
like this:

                if (!static_key_true(&___done_key))                     \
                        ___ret = __net_get_random_once(buf,             \

expands to

                if (!!static_key_false(&___done_key))                     \
                        ___ret = __net_get_random_once(buf,             \

So we get true at boot time and as soon as static_key_slow_inc is called
on the key it will invert the logic and return false for the fast path.
static_key_slow_inc will change the branch because it got initialized
with .enabled == 0. After static_key_slow_inc is called on the key the
branch is replaced with a nop again.

=== Misc: ===
The helper defers the increment into a workqueue so we don't
have problems calling this code from atomic sections. A seperate boolean
(___done) guards the case where we enter net_get_random_once again before
the increment happend.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now inet_gso_segment() is stackable, its relatively easy to
implement GSO/TSO support for IPIP

Performance results, when segmentation is done after tunnel
device (as no NIC is yet enabled for TSO IPIP support) :

Before patch :

lpq83:~# ./netperf -H 7.7.9.84 -Cc
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 7.7.9.84 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  16384  16384    10.00      3357.88   5.09     3.70     2.983   2.167

After patch :

lpq83:~# ./netperf -H 7.7.9.84 -Cc
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 7.7.9.84 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  16384  16384    10.00      7710.19   4.52     6.62     1.152   1.687
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to support GSO on IPIP, we need to make
inet_gso_segment() stackable.

It should not assume network header starts right after mac
header.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While implementing GSO/TSO support for IPIP, I found skb_segment()
was assuming network header was immediately following mac header.

Its not really true in the case inet_gso_segment() is stacked :
By the time tcp_gso_segment() is called, network header points
to the inner IP header.

Let's instead assume nothing and pick the current offsets found in
original skb, we have skb_headers_offset_update() helper for that.

Also move the csum_start update inside skb_headers_offset_update()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While working on virtio_net new allocation strategy to increase
payload/truesize ratio, we found that refactoring sk_page_frag_refill()
was needed.

This patch splits sk_page_frag_refill() into two parts, adding
skb_page_frag_refill() which can be used without a socket.

While we are at it, add a minimum frag size of 32 for
sk_page_frag_refill()

Michael will either use netdev_alloc_frag() from softirq context,
or skb_page_frag_refill() from process context in refill_work()
 (GFP_KERNEL allocations)
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Michael Dalton <mwdalton@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

skb_gro_receive() is currently limited to 16 or 17 MSS per GRO skb,
typically 24616 bytes, because it fills up to MAX_SKB_FRAGS frags.

It's relatively easy to extend the skb using frag_list to allow
more frags to be appended into the last sk_buff.

This still builds very efficient skbs, and allows reaching 45 MSS per
skb.

(45 MSS GRO packet uses one skb plus a frag_list containing 2 additional
sk_buff)

High speed TCP flows benefit from this extension by lowering TCP stack
cpu usage (less packets stored in receive queue, less ACK packets
processed)

Forwarding setups could be hurt, as such skbs will need to be
linearized, although its not a new problem, as GRO could already
provide skbs with a frag_list.

We could make the 65536 bytes threshold a tunable to mitigate this.

(First time we need to linearize skb in skb_needs_linearize(), we could
lower the tunable to ~16*1460 so that following skb_gro_receive() calls
build smaller skbs)
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Steinar reported FQ pacing was not working for UDP flows.

It looks like the initial sk->sk_pacing_rate value of 0 was
a wrong choice. We should init it to ~0U (unlimited)

Then, TCA_FQ_FLOW_DEFAULT_RATE should be removed because it makes
no real sense. The default rate is really unlimited, and we
need to avoid a zero divide.
Reported-by: NSteinar H. Gunderson <sesse@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the tasks have been migrated to the cgroup,
there is no need to call task_netprioidx to get
task's cgroup id.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Separate the unreg_list and the close_list in dev_close_many preventing
dev_close_many from permuting the unreg_list.  The permutations of the
unreg_list have resulted in cases where the loopback device is accessed
it has been freed in code such as dst_ifdown.  Resulting in subtle memory
corruption.

This is the second bug from sharing the storage between the close_list
and the unreg_list.  The issues that crop up with sharing are
apparently too subtle to show up in normal testing or usage, so let's
forget about being clever and use two separate lists.

v2: Make all callers pass in a close_list to dev_close_many
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

on x86 system with net.core.bpf_jit_enable = 1

sudo tcpdump -i eth1 'tcp port 22'

causes the warning:
[   56.766097]  Possible unsafe locking scenario:
[   56.766097]
[   56.780146]        CPU0
[   56.786807]        ----
[   56.793188]   lock(&(&vb->lock)->rlock);
[   56.799593]   <Interrupt>
[   56.805889]     lock(&(&vb->lock)->rlock);
[   56.812266]
[   56.812266]  *** DEADLOCK ***
[   56.812266]
[   56.830670] 1 lock held by ksoftirqd/1/13:
[   56.836838]  #0:  (rcu_read_lock){.+.+..}, at: [<ffffffff8118f44c>] vm_unmap_aliases+0x8c/0x380
[   56.849757]
[   56.849757] stack backtrace:
[   56.862194] CPU: 1 PID: 13 Comm: ksoftirqd/1 Not tainted 3.12.0-rc3+ #45
[   56.868721] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012
[   56.882004]  ffffffff821944c0 ffff88080bbdb8c8 ffffffff8175a145 0000000000000007
[   56.895630]  ffff88080bbd5f40 ffff88080bbdb928 ffffffff81755b14 0000000000000001
[   56.909313]  ffff880800000001 ffff880800000000 ffffffff8101178f 0000000000000001
[   56.923006] Call Trace:
[   56.929532]  [<ffffffff8175a145>] dump_stack+0x55/0x76
[   56.936067]  [<ffffffff81755b14>] print_usage_bug+0x1f7/0x208
[   56.942445]  [<ffffffff8101178f>] ? save_stack_trace+0x2f/0x50
[   56.948932]  [<ffffffff810cc0a0>] ? check_usage_backwards+0x150/0x150
[   56.955470]  [<ffffffff810ccb52>] mark_lock+0x282/0x2c0
[   56.961945]  [<ffffffff810ccfed>] __lock_acquire+0x45d/0x1d50
[   56.968474]  [<ffffffff810cce6e>] ? __lock_acquire+0x2de/0x1d50
[   56.975140]  [<ffffffff81393bf5>] ? cpumask_next_and+0x55/0x90
[   56.981942]  [<ffffffff810cef72>] lock_acquire+0x92/0x1d0
[   56.988745]  [<ffffffff8118f52a>] ? vm_unmap_aliases+0x16a/0x380
[   56.995619]  [<ffffffff817628f1>] _raw_spin_lock+0x41/0x50
[   57.002493]  [<ffffffff8118f52a>] ? vm_unmap_aliases+0x16a/0x380
[   57.009447]  [<ffffffff8118f52a>] vm_unmap_aliases+0x16a/0x380
[   57.016477]  [<ffffffff8118f44c>] ? vm_unmap_aliases+0x8c/0x380
[   57.023607]  [<ffffffff810436b0>] change_page_attr_set_clr+0xc0/0x460
[   57.030818]  [<ffffffff810cfb8d>] ? trace_hardirqs_on+0xd/0x10
[   57.037896]  [<ffffffff811a8330>] ? kmem_cache_free+0xb0/0x2b0
[   57.044789]  [<ffffffff811b59c3>] ? free_object_rcu+0x93/0xa0
[   57.051720]  [<ffffffff81043d9f>] set_memory_rw+0x2f/0x40
[   57.058727]  [<ffffffff8104e17c>] bpf_jit_free+0x2c/0x40
[   57.065577]  [<ffffffff81642cba>] sk_filter_release_rcu+0x1a/0x30
[   57.072338]  [<ffffffff811108e2>] rcu_process_callbacks+0x202/0x7c0
[   57.078962]  [<ffffffff81057f17>] __do_softirq+0xf7/0x3f0
[   57.085373]  [<ffffffff81058245>] run_ksoftirqd+0x35/0x70

cannot reuse jited filter memory, since it's readonly,
so use original bpf insns memory to hold work_struct

defer kfree of sk_filter until jit completed freeing

tested on x86_64 and i386
Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

virtio wants to pass in cpumask_of(cpu), make parameter
const to avoid build warnings.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Factor out the code that extracts the ports from skb_flow_dissect and
add a new function skb_flow_get_ports which can be re-used.
Suggested-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Reviewed-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 8ed78166 ("flow_keys: include thoff into flow_keys for
later usage"), we missed that existing code was using nhoff as a
temporary variable that could not always contain transport header
offset.

This is not a problem for TCP/UDP because port offset (@poff)
is 0 for these protocols.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: NNikolay Aleksandrov <nikolay@redhat.com>
Acked-by: NDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When flags IFF_PROMISC and IFF_ALLMULTI are changed, netlink messages are not
consistent. For example, if a multicast daemon is running (flag IFF_ALLMULTI
set in dev->flags but not dev->gflags, ie not exported to userspace) and then a
user sets it via netlink (flag IFF_ALLMULTI set in dev->flags and dev->gflags, ie
exported to userspace), no netlink message is sent.
Same for IFF_PROMISC and because dev->promiscuity is exported via
IFLA_PROMISCUITY, we may send a netlink message after each change of this
counter.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch only prepares the next one, there is no functional change.
Now, __dev_notify_flags() can also be used to notify flags changes via
rtnetlink.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As mentioned in commit afe4fd06 ("pkt_sched: fq: Fair Queue packet
scheduler"), this patch adds a new socket option.

SO_MAX_PACING_RATE offers the application the ability to cap the
rate computed by transport layer. Value is in bytes per second.

u32 val = 1000000;
setsockopt(sockfd, SOL_SOCKET, SO_MAX_PACING_RATE, &val, sizeof(val));

To be effectively paced, a flow must use FQ packet scheduler.

Note that a packet scheduler takes into account the headers for its
computations. The effective payload rate depends on MSS and retransmits
if any.

I chose to make this pacing rate a SOL_SOCKET option instead of a
TCP one because this can be used by other protocols.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A host might need net_secret[] and never open a single socket.

Problem added in commit aebda156
("net: defer net_secret[] initialization")

Based on prior patch from Hannes Frederic Sowa.
Reported-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NHannes Frederic Sowa <hannes@strressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is currently serialization network namespaces exiting and
network devices exiting as the final part of netdev_run_todo does not
happen under the rtnl_lock.  This is compounded by the fact that the
only list of devices unregistering in netdev_run_todo is local to the
netdev_run_todo.

This lack of serialization in extreme cases results in network devices
unregistering in netdev_run_todo after the loopback device of their
network namespace has been freed (making dst_ifdown unsafe), and after
the their network namespace has exited (making the NETDEV_UNREGISTER,
and NETDEV_UNREGISTER_FINAL callbacks unsafe).

Add the missing serialization by a per network namespace count of how
many network devices are unregistering and having a wait queue that is
woken up whenever the count is decreased.  The count and wait queue
allow default_device_exit_batch to wait until all of the unregistration
activity for a network namespace has finished before proceeding to
unregister the loopback device and then allowing the network namespace
to exit.

Only a single global wait queue is used because there is a single global
lock, and there is a single waiter, per network namespace wait queues
would be a waste of resources.

The per network namespace count of unregistering devices gives a
progress guarantee because the number of network devices unregistering
in an exiting network namespace must ultimately drop to zero (assuming
network device unregistration completes).

The basic logic remains the same as in v1.  This patch is now half
comment and half rtnl_lock_unregistering an expanded version of
wait_event performs no extra work in the common case where no network
devices are unregistering when we get to default_device_exit_batch.
Reported-by: NFrancesco Ruggeri <fruggeri@aristanetworks.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Also, remove the same functionality from bonding - it will be already done
for any device that links to its lower/upper neighbour.

The links will be created for dev's kobject, and will look like
lower_eth0 for lower device eth0 and upper_bridge0 for upper device
bridge0.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, we can have only one master upper neighbour, so it would be
useful to create a symlink to it in the sysfs device directory, the way
that bonding now does it, for every device. Lower devices from
bridge/team/etc will automagically get it, so we could rely on it.

Also, remove the same functionality from bonding.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It will be useful to get first/last element.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a possibility to iterate through netdev_adjacent's private, currently
only for lower neighbours.

Add both RCU and RTNL/other locking variants of iterators, and make the
non-rcu variant to be safe from removal.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, even though we can access any linked device, we can't attach
anything to it, which is vital to properly manage them.

To fix this, add a new void *private to netdev_adjacent and functions
setting/getting it (per link), so that we can save, per example, bonding's
slave structures there, per slave device.

netdev_master_upper_dev_link_private(dev, upper_dev, private) links dev to
upper dev and populates the neighbour link only with private.

netdev_lower_dev_get_private{,_rcu}() returns the private, if found.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we have only the RTNL flavour, however we can traverse it while
holding only RCU, so add the RCU search. Add an RCU variant that uses
list_head * as an argument, so that it can be universally used afterwards.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Cong Wang <amwang@redhat.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, we distinguish neighbours (first-level linked devices) from
non-neighbours by the neighbour bool in the netdev_adjacent. This could be
quite time-consuming in case we would like to traverse *only* through
neighbours - cause we'd have to traverse through all devices and check for
this flag, and in a (quite common) scenario where we have lots of vlans on
top of bridge, which is on top of a bond - the bonding would have to go
through all those vlans to get its upper neighbour linked devices.

This situation is really unpleasant, cause there are already a lot of cases
when a device with slaves needs to go through them in hot path.

To fix this, introduce a new upper/lower device lists structure -
adj_list, which contains only the neighbours. It works always in
pair with the all_adj_list structure (renamed from upper/lower_dev_list),
i.e. both of them contain the same links, only that all_adj_list contains
also non-neighbour device links. It's really a small change visible,
currently, only for __netdev_adjacent_dev_insert/remove(), and doesn't
change the main linked logic at all.

Also, add some comments a fix a name collision in
netdev_for_each_upper_dev_rcu() and rework the naming by the following
rules:

netdev_(all_)(upper|lower)_*

If "all_" is present, then we work with the whole list of upper/lower
devices, otherwise - only with direct neighbours. Uninline functions - to
get better stack traces.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Cong Wang <amwang@redhat.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we make use of bool upper when we want to specify if we want to
work with upper/lower list. It's, however, harder to read, debug and
occupies a lot more code.

Fix this by just passing the correct upper/lower_dev_list list_head pointer
instead of bool upper, and work internally with it.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Cong Wang <amwang@redhat.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we always use the first member of the arp_queue to determine
the sender ip address of the arp packet (or in case of IPv6 - source
address of the ndisc packet). This skb is fixed as long as the queue is
not drained by a complete purge because of a timeout or by a successful
response.

If the first packet enqueued on the arp_queue is from a local application
with a manually set source address and the to be discovered system
does some kind of uRPF checks on the source address in the arp packet
the resolving process hangs until a timeout and restarts. This hurts
communication with the participating network node.

This could be mitigated a bit if we use the latest enqueued skb's
source address for the resolving process, which is not as static as
the arp_queue's head. This change of the source address could result in
better recovery of a failed solicitation.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Julian Anastasov <ja@ssi.bg>
Reviewed-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I've been hitting a NULL ptr deref while using netconsole because the
np->dev check and the pointer manipulation in netpoll_cleanup are done
without rtnl and the following sequence happens when having a netconsole
over a vlan and we remove the vlan while disabling the netconsole:
	CPU 1					CPU2
					removes vlan and calls the notifier
enters store_enabled(), calls
netdev_cleanup which checks np->dev
and then waits for rtnl
					executes the netconsole netdev
					release notifier making np->dev
					== NULL and releases rtnl
continues to dereference a member of
np->dev which at this point is == NULL
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The received ARP request type in the Ethernet packet head is ETH_P_ARP other than ETH_P_IP.

[ Bug introduced by commit b7394d24
  ("netpoll: prepare for ipv6") ]
Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 416186fb ("net: Split core bits of netdev_pick_tx
into __netdev_pick_tx") added a bug that disables caching of queue
index in the socket.

This is the source of packet reorders for TCP flows, and
again this is happening more often when using FQ pacing.

Old code was doing

if (queue_index != old_index)
	sk_tx_queue_set(sk, queue_index);

Alexander renamed the variables but forgot to change sk_tx_queue_set()
2nd parameter.

if (queue_index != new_index)
	sk_tx_queue_set(sk, queue_index);

This means we store -1 over and over in sk->sk_tx_queue_mapping
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we're linking upper devices to lower ones, which results in
upside-down relationship: upper devices seeing lower devices via its upper
lists.

Fix this by correctly linking lower devices to the upper ones.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Cong Wang <amwang@redhat.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This function was only used when a packet was sent to another netns. Now, it can
also be used after tunnel encapsulation or decapsulation.

Only skb_orphan() should not be done when a packet is not crossing netns.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This config option is superfluous in that it only guards a call
to neigh_app_ns(). Enabling CONFIG_ARPD by default has no
change in behavior. There will now be call to __neigh_notify()
for each ARP resolution, which has no impact unless there is a
user space daemon waiting to receive the notification, i.e.,
the case for which CONFIG_ARPD was designed anyways.
Suggested-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Joe Perches <joe@perches.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Reviewed-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

nsown_capable is a special case of ns_capable essentially for just CAP_SETUID and
CAP_SETGID.  For the existing users it doesn't noticably simplify things and
from the suggested patches I have seen it encourages people to do the wrong
thing.  So remove nsown_capable.
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

By default, the pfifo_fast queue discipline has been used by default
for all devices. But we have better choices now.

This patch allow setting the default queueing discipline with sysctl.
This allows easy use of better queueing disciplines on all devices
without having to use tc qdisc scripts. It is intended to allow
an easy path for distributions to make fq_codel or sfq the default
qdisc.

This patch also makes pfifo_fast more of a first class qdisc, since
it is now possible to manually override the default and explicitly
use pfifo_fast. The behavior for systems who do not use the sysctl
is unchanged, they still get pfifo_fast

Also removes leftover random # in sysctl net core.
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 8728c544 ("net: dev_pick_tx() fix") and commit
b6fe83e9 ("bonding: refine IFF_XMIT_DST_RELEASE capability")
are quite incompatible : Queue selection is disabled because skb
dst was dropped before entering bonding device.

This causes major performance regression, mainly because TCP packets
for a given flow can be sent to multiple queues.

This is particularly visible when using the new FQ packet scheduler
with MQ + FQ setup on the slaves.

We can safely revert the first commit now that 416186fb
("net: Split core bits of netdev_pick_tx into __netdev_pick_tx")
properly caps the queue_index.
Reported-by: NXi Wang <xii@google.com>
Diagnosed-by: NXi Wang <xii@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Denys Fedorysychenko <nuclearcat@nuclearcat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This function returns the next dev in the dev->upper_dev_list after the
struct list_head **iter position, and updates *iter accordingly. Returns
NULL if there are no devices left.

Caller must hold RCU read lock.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Cong Wang <amwang@redhat.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We already don't need it cause we see every upper/lower device in the list
already.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Cong Wang <amwang@redhat.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>