Allocate enough space so as not to force the outgoing net device to do
skb_realloc_headroom().

Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

pktgen_thread_worker() doesn't need to wait for kthread_stop(), it
can simply exit. Just pktgen_create_thread() and pg_net_exit() should
do get_task_struct()/put_task_struct(). kthread_stop(dead_thread) is
fine.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

pktgen_thread_worker() is obviously racy, kthread_stop() can come
between the kthread_should_stop() check and set_current_state().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Jan Stancek <jstancek@redhat.com>
Reported-by: Marcelo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/pktgen.c:2672:43: warning: incorrect type in assignment (different base types)
net/core/pktgen.c:2672:43:    expected unsigned short [unsigned] [short] [usertype] <noident>
net/core/pktgen.c:2672:43:    got restricted __be16 [usertype] protocol

Let's use proper struct ethhdr instead of hard coding everything.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Giving /proc/net/pktgen/pgctrl an invalid command just returns shell
success and prints a warning in dmesg.  This is not very useful for
shell scripting, as it can only detect the error by parsing dmesg.

Instead return -EINVAL when the command is unknown, as this provides
userspace shell scripting a way of detecting this.

Also bump version tag to 2.75, because (1) reading /proc/net/pktgen/pgctrl
output this version number which would allow to detect this small
semantic change, and (2) because the pktgen version tag have not been
updated since 2010.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Too many spaces were introduced in commit 63adc6fb ("pktgen: cleanup
checkpatch warnings"), thus misaligning "src_min:" to other columns.

Fixes: 63adc6fb

 ("pktgen: cleanup checkpatch warnings")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

pkt_gen->last_ok was not set properly, so after the first burst
pktgen instead of allocating new packet, will reuse old one, advance
eth_type_trans further, which would mean the stack will be seeing very
short bogus packets.

Fixes: 62f64aed

 ("pktgen: introduce xmit_mode '<start_xmit|netif_receive>'")
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce xmit_mode 'netif_receive' for pktgen which generates the
packets using familiar pktgen commands, but feeds them into
netif_receive_skb() instead of ndo_start_xmit().

Default mode is called 'start_xmit'.

It is designed to test netif_receive_skb and ingress qdisc
performace only. Make sure to understand how it works before
using it for other rx benchmarking.

Sample script 'pktgen.sh':
\#!/bin/bash
function pgset() {
  local result

  echo $1 > $PGDEV

  result=`cat $PGDEV | fgrep "Result: OK:"`
  if [ "$result" = "" ]; then
    cat $PGDEV | fgrep Result:
  fi
}

[ -z "$1" ] && echo "Usage: $0 DEV" && exit 1
ETH=$1

PGDEV=/proc/net/pktgen/kpktgend_0
pgset "rem_device_all"
pgset "add_device $ETH"

PGDEV=/proc/net/pktgen/$ETH
pgset "xmit_mode netif_receive"
pgset "pkt_size 60"
pgset "dst 198.18.0.1"
pgset "dst_mac 90:e2:ba:ff:ff:ff"
pgset "count 10000000"
pgset "burst 32"

PGDEV=/proc/net/pktgen/pgctrl
echo "Running... ctrl^C to stop"
pgset "start"
echo "Done"
cat /proc/net/pktgen/$ETH

Usage:
$ sudo ./pktgen.sh eth2
...
Result: OK: 232376(c232372+d3) usec, 10000000 (60byte,0frags)
  43033682pps 20656Mb/sec (20656167360bps) errors: 10000000

Raw netif_receive_skb speed should be ~43 million packet
per second on 3.7Ghz x86 and 'perf report' should look like:
  37.69%  kpktgend_0   [kernel.vmlinux]  [k] __netif_receive_skb_core
  25.81%  kpktgend_0   [kernel.vmlinux]  [k] kfree_skb
   7.22%  kpktgend_0   [kernel.vmlinux]  [k] ip_rcv
   5.68%  kpktgend_0   [pktgen]          [k] pktgen_thread_worker

If fib_table_lookup is seen on top, it means skb was processed
by the stack. To benchmark netif_receive_skb only make sure
that 'dst_mac' of your pktgen script is different from
receiving device mac and it will be dropped by ip_rcv

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Allow flag NO_TIMESTAMP to turn timestamping on again, like other flags,
with a negation of the flag like !NO_TIMESTAMP.

Also document the option flag NO_TIMESTAMP.

Fixes: afb84b62

 ("pktgen: add flag NO_TIMESTAMP to disable timestamping")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The check for hrtimer_active() after starting the timer is
pointless. If the timer is inactive it has expired already and
therefor the task pointer is already NULL.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20150414203503.165258315@linutronix.de


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Trying to use burst capability (aka xmit_more) on a virtual device
like bonding is not supported.

For example, skb might be queued multiple times on a qdisc, with
various list corruptions.

Fixes: 38b2cf29

 ("net: pktgen: packet bursting via skb->xmit_more")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Spelling errors caught by codespell.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes two issues in UDP checksum computation in pktgen.

First, the pseudo-header uses the source and destination IP
addresses. Currently, the ports are used for IPv4.

Second, the UDP checksum covers both header and data.  So we need to
generate the data earlier (move pktgen_finalize_skb up), and compute
the checksum for UDP header + data.

Fixes: c26bf4a5

 ("pktgen: Add UDPCSUM flag to support UDP checksums")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

The proc_remove() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch demonstrates the effect of delaying update of HW tailptr.
(based on earlier patch by Jesper)

burst=1 is the default. It sends one packet with xmit_more=false
burst=2 sends one packet with xmit_more=true and
        2nd copy of the same packet with xmit_more=false
burst=3 sends two copies of the same packet with xmit_more=true and
        3rd copy with xmit_more=false

Performance with ixgbe (usec 30):
burst=1  tx:9.2 Mpps
burst=2  tx:13.5 Mpps
burst=3  tx:14.5 Mpps full 10G line rate

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the more common pr_warn.
Realign arguments.

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

Then testing the TX limits of the stack, then it is useful to
be-able to disable the do_gettimeofday() timetamping on every packet.

This implements a pktgen flag NO_TIMESTAMP which will disable this
call to do_gettimeofday().

The performance change on (my system E5-2695) with skb_clone=0, goes
from TX 2,423,751 pps to 2,567,165 pps with flag NO_TIMESTAMP. Thus,
the cost of do_gettimeofday() or saving is approx 23 nanosec.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For now it will always be false.

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

That way we don't have to audit every call site to make sure it is
doing this properly.

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

Replace occurences of skb_get_queue_mapping() and follow-up
netdev_get_tx_queue() with an actual helper function.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

The if_lock()/if_unlock() in next_to_run() adds a significant
overhead, because its called for every packet in busy loop of
pktgen_thread_worker().  (Thomas Graf originally pointed me
at this lock problem).

Removing these two "LOCK" operations should in theory save us approx
16ns (8ns x 2), as illustrated below we do save 16ns when removing
the locks and introducing RCU protection.

Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30:
 (single CPU performance, ixgbe 10Gbit/s, E5-2630)
 * Prev   : 5684009 pps --> 175.93ns (1/5684009*10^9)
 * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9)
 * Diff   : +588195 pps --> -16.50ns

To understand this RCU patch, I describe the pktgen thread model
below.

In pktgen there is several kernel threads, but there is only one CPU
running each kernel thread.  Communication with the kernel threads are
done through some thread control flags.  This allow the thread to
change data structures at a know synchronization point, see main
thread func pktgen_thread_worker().

Userspace changes are communicated through proc-file writes.  There
are three types of changes, general control changes "pgctrl"
(func:pgctrl_write), thread changes "kpktgend_X"
(func:pktgen_thread_write), and interface config changes "etcX@N"
(func:pktgen_if_write).

Userspace "pgctrl" and "thread" changes are synchronized via the mutex
pktgen_thread_lock, thus only a single userspace instance can run.
The mutex is taken while the packet generator is running, by pgctrl
"start".  Thus e.g. "add_device" cannot be invoked when pktgen is
running/started.

All "pgctrl" and all "thread" changes, except thread "add_device",
communicate via the thread control flags.  The main problem is the
exception "add_device", that modifies threads "if_list" directly.

Fortunately "add_device" cannot be invoked while pktgen is running.
But there exists a race between "rem_device_all" and "add_device"
(which normally don't occur, because "rem_device_all" waits 125ms
before returning). Background'ing "rem_device_all" and running
"add_device" immediately allow the race to occur.

The race affects the threads (list of devices) "if_list".  The if_lock
is used for protecting this "if_list".  Other readers are given
lock-free access to the list under RCU read sections.

Note, interface config changes (via proc) can occur while pktgen is
running, which worries me a bit.  I'm assuming proc_remove() takes
appropriate locks, to assure no writers exists after proc_remove()
finish.

I've been running a script exercising the race condition (leading me
to fix the proc_remove order), without any issues.  The script also
exercises concurrent proc writes, while the interface config is
getting removed.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Avoid calling set_current_state() inside the busy-loop in
pktgen_thread_worker().  In case of pkt_dev->delay, then it is still
used/enabled in pktgen_xmit() via the spin() call.

The set_current_state(TASK_INTERRUPTIBLE) uses a xchg, which implicit
is LOCK prefixed.  I've measured the asm LOCK operation to take approx
8ns on this E5-2630 CPU.  Performance increase corrolate with this
measurement.

Performance data with CLONE_SKB==100000, rx-usecs=30:
 (single CPU performance, ixgbe 10Gbit/s, E5-2630)
 * Prev:  5454050 pps --> 183.35ns (1/5454050*10^9)
 * Now:   5684009 pps --> 175.93ns (1/5684009*10^9)
 * Diff:  +229959 pps -->  -7.42ns

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Similarly to commit 43279500

 ("packet: respect devices with
LLTX flag in direct xmit"), we can basically apply the very same
to pktgen. This will help testing against LLTX devices such as
dummy driver (or others), which only have a single netdevice txq
and would otherwise require locking their txq from pktgen side
while e.g. in dummy case, we would not need any locking. Fix this
by making use of HARD_TX_{UN,}LOCK API, so that NETIF_F_LLTX will
be respected.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Similarly as in commit 8e2f1a63

 ("packet: fix packet_direct_xmit
for BQL enabled drivers"), we test for __QUEUE_STATE_STACK_XOFF bit
in pktgen's xmit, which would not fully fill the device's TX ring for
BQL drivers that use netdev_tx_sent_queue(). Fix is to use, similarly
as we do in packet sockets, netif_xmit_frozen_or_drv_stopped() test.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The documentation misses a few of the supported flags. Fix this. Also
respect the dependency to CONFIG_XFRM for the IPSEC flag.

Cc: Fan Du <fan.du@windriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 'out' label is just a relict from previous times as pgctrl_write()
had multiple error paths. Get rid of it and simply return right away
on errors.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If a privileged user writes an empty string to /proc/net/pktgen/pgctrl
the code for stripping the (then non-existent) '\n' actually writes the
zero byte at index -1 of data[]. The then still uninitialized array will
very likely fail the command matching tests and the pr_warning() at the
end will therefore leak stack bytes to the kernel log.

Fix those issues by simply ensuring we're passed a non-empty string as
the user API apparently expects a trailing '\n' for all commands.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use ether_addr_copy instead of memcpy(a, b, ETH_ALEN) to
save some cycles on arm and powerpc.

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

0-DAY kernel build testing backend reported below error:
All error/warnings:

   net/core/pktgen.c: In function 'pktgen_if_write':
>> >> net/core/pktgen.c:1487:10: error: 'struct pktgen_dev' has no member named 'spi'
>> >> net/core/pktgen.c:1488:43: error: 'struct pktgen_dev' has no member named 'spi'

Fix this by encapuslating the code with CONFIG_XFRM.

Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

CC: Fan Du <fan.du@windriver.com>
CC: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

If user run pktgen plus ipsec by using spi, show spi value
properly when cat /proc/net/pktgen/ethX

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

Introduce xfrm_state_lookup_byspi to find user specified by custom
from "pgset spi xxx". Using this scheme, any flow regardless its
saddr/daddr could be transform by SA specified with configurable
spi.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

IPsec tunnel mode encapuslation needs to set outter ip header
with right protocol/ttl/id value with regard to skb->dst->child.

Looking up a rt in a standard way is absolutely wrong for every
packet transmission. In a simple way, construct a dst by setting
neccessary information to make tunnel mode encapuslation working.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

User could set specific SPI value to arm pktgen flow with IPsec
transformation, instead of looking up SA by sadr/daddr. The reaseon
to do so is because current state lookup scheme is both slow and, most
important of all, in fact pktgen doesn't need to match any SA state
addresses information, all it needs is the SA transfromation shell to
do the encapuslation.

And this option also provide user an alternative to using pktgen
test existing SA without creating new ones.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

so /proc/net/xfrm_stat could give user clue about what's
wrong in this process.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

xfrm_state lock protects its state, i.e., VALID/DEAD and statistics,
not the transforming procedure, as both mode/type output functions
are reentrant.

Another issue is state lock can be used in BH context when state timer
alarmed, after transformation in pktgen, update state statistics acquiring
state lock should disabled BH context for a moment. Otherwise LOCKDEP
critisize this:

[   62.354339] pktgen: Packet Generator for packet performance testing. Version: 2.74
[   62.655444]
[   62.655448] =================================
[   62.655451] [ INFO: inconsistent lock state ]
[   62.655455] 3.13.0-rc2+ #70 Not tainted
[   62.655457] ---------------------------------
[   62.655459] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[   62.655463] kpktgend_0/2764 [HC0[0]:SC0[0]:HE1:SE1] takes:
[   62.655466]  (&(&x->lock)->rlock){+.?...}, at: [<ffffffffa00886f6>] pktgen_thread_worker+0x1796/0x1860 [pktgen]
[   62.655479] {IN-SOFTIRQ-W} state was registered at:
[   62.655484]   [<ffffffff8109a61d>] __lock_acquire+0x62d/0x1d70
[   62.655492]   [<ffffffff8109c3c7>] lock_acquire+0x97/0x130
[   62.655498]   [<ffffffff81774af6>] _raw_spin_lock+0x36/0x70
[   62.655505]   [<ffffffff816dc3a3>] xfrm_timer_handler+0x43/0x290
[   62.655511]   [<ffffffff81059437>] __tasklet_hrtimer_trampoline+0x17/0x40
[   62.655519]   [<ffffffff8105a1b7>] tasklet_hi_action+0xd7/0xf0
[   62.655523]   [<ffffffff81059ac6>] __do_softirq+0xe6/0x2d0
[   62.655526]   [<ffffffff8105a026>] irq_exit+0x96/0xc0
[   62.655530]   [<ffffffff8177fd0a>] smp_apic_timer_interrupt+0x4a/0x60
[   62.655537]   [<ffffffff8177e96f>] apic_timer_interrupt+0x6f/0x80
[   62.655541]   [<ffffffff8100b7c6>] arch_cpu_idle+0x26/0x30
[   62.655547]   [<ffffffff810ace28>] cpu_startup_entry+0x88/0x2b0
[   62.655552]   [<ffffffff81761c3c>] rest_init+0xbc/0xd0
[   62.655557]   [<ffffffff81ea5e5e>] start_kernel+0x3c4/0x3d1
[   62.655583]   [<ffffffff81ea55a8>] x86_64_start_reservations+0x2a/0x2c
[   62.655588]   [<ffffffff81ea569f>] x86_64_start_kernel+0xf5/0xfc
[   62.655592] irq event stamp: 77
[   62.655594] hardirqs last  enabled at (77): [<ffffffff810ab7f2>] vprintk_emit+0x1b2/0x520
[   62.655597] hardirqs last disabled at (76): [<ffffffff810ab684>] vprintk_emit+0x44/0x520
[   62.655601] softirqs last  enabled at (22): [<ffffffff81059b57>] __do_softirq+0x177/0x2d0
[   62.655605] softirqs last disabled at (15): [<ffffffff8105a026>] irq_exit+0x96/0xc0
[   62.655609]
[   62.655609] other info that might help us debug this:
[   62.655613]  Possible unsafe locking scenario:
[   62.655613]
[   62.655616]        CPU0
[   62.655617]        ----
[   62.655618]   lock(&(&x->lock)->rlock);
[   62.655622]   <Interrupt>
[   62.655623]     lock(&(&x->lock)->rlock);
[   62.655626]
[   62.655626]  *** DEADLOCK ***
[   62.655626]
[   62.655629] no locks held by kpktgend_0/2764.
[   62.655631]
[   62.655631] stack backtrace:
[   62.655636] CPU: 0 PID: 2764 Comm: kpktgend_0 Not tainted 3.13.0-rc2+ #70
[   62.655638] Hardware name: innotek GmbH VirtualBox, BIOS VirtualBox 12/01/2006
[   62.655642]  ffffffff8216b7b0 ffff88001be43ab8 ffffffff8176af37 0000000000000007
[   62.655652]  ffff88001c8d4fc0 ffff88001be43b18 ffffffff81766d78 0000000000000000
[   62.655663]  ffff880000000001 ffff880000000001 ffffffff8101025f ffff88001be43b18
[   62.655671] Call Trace:
[   62.655680]  [<ffffffff8176af37>] dump_stack+0x46/0x58
[   62.655685]  [<ffffffff81766d78>] print_usage_bug+0x1f1/0x202
[   62.655691]  [<ffffffff8101025f>] ? save_stack_trace+0x2f/0x50
[   62.655696]  [<ffffffff81099f8c>] mark_lock+0x28c/0x2f0
[   62.655700]  [<ffffffff810994b0>] ? check_usage_forwards+0x150/0x150
[   62.655704]  [<ffffffff8109a67a>] __lock_acquire+0x68a/0x1d70
[   62.655712]  [<ffffffff81115b09>] ? irq_work_queue+0x69/0xb0
[   62.655717]  [<ffffffff810ab7f2>] ? vprintk_emit+0x1b2/0x520
[   62.655722]  [<ffffffff8109cec5>] ? trace_hardirqs_on_caller+0x105/0x1d0
[   62.655730]  [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen]
[   62.655734]  [<ffffffff8109c3c7>] lock_acquire+0x97/0x130
[   62.655741]  [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen]
[   62.655745]  [<ffffffff81774af6>] _raw_spin_lock+0x36/0x70
[   62.655752]  [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen]
[   62.655758]  [<ffffffffa00886f6>] pktgen_thread_worker+0x1796/0x1860 [pktgen]
[   62.655766]  [<ffffffffa0087a79>] ? pktgen_thread_worker+0xb19/0x1860 [pktgen]
[   62.655771]  [<ffffffff8109cf9d>] ? trace_hardirqs_on+0xd/0x10
[   62.655777]  [<ffffffff81775410>] ? _raw_spin_unlock_irq+0x30/0x40
[   62.655785]  [<ffffffff8151faa0>] ? e1000_clean+0x9d0/0x9d0
[   62.655791]  [<ffffffff81094310>] ? __init_waitqueue_head+0x60/0x60
[   62.655795]  [<ffffffff81094310>] ? __init_waitqueue_head+0x60/0x60
[   62.655800]  [<ffffffffa0086f60>] ? mod_cur_headers+0x7f0/0x7f0 [pktgen]
[   62.655806]  [<ffffffff81078f84>] kthread+0xe4/0x100
[   62.655813]  [<ffffffff81078ea0>] ? flush_kthread_worker+0x170/0x170
[   62.655819]  [<ffffffff8177dc6c>] ret_from_fork+0x7c/0xb0
[   62.655824]  [<ffffffff81078ea0>] ? flush_kthread_worker+0x170/0x170

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

commit a553e4a6

 ("[PKTGEN]: IPSEC support")
tried to support IPsec ESP transport transformation for pktgen, but acctually
this doesn't work at all for two reasons(The orignal transformed packet has
bad IPv4 checksum value, as well as wrong auth value, reported by wireshark)

- After transpormation, IPv4 header total length needs update,
  because encrypted payload's length is NOT same as that of plain text.

- After transformation, IPv4 checksum needs re-caculate because of payload
  has been changed.

With this patch, armmed pktgen with below cofiguration, Wireshark is able to
decrypted ESP packet generated by pktgen without any IPv4 checksum error or
auth value error.

pgset "flag IPSEC"
pgset "flows 1"

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>