Julia Lawall says:

====================
add missing of_node_put

The various for_each device_node iterators performs an of_node_get on each
iteration, so a break out of the loop requires an of_node_put.

The complete semantic patch that fixes this problem is
(http://coccinelle.lip6.fr):

// <smpl>
@r@
local idexpression n;
expression e1,e2;
iterator name for_each_node_by_name, for_each_node_by_type,
for_each_compatible_node, for_each_matching_node,
for_each_matching_node_and_match, for_each_child_of_node,
for_each_available_child_of_node, for_each_node_with_property;
iterator i;
statement S;
expression list [n1] es;
@@

(
(
for_each_node_by_name(n,e1) S
|
for_each_node_by_type(n,e1) S
|
for_each_compatible_node(n,e1,e2) S
|
for_each_matching_node(n,e1) S
|
for_each_matching_node_and_match(n,e1,e2) S
|
for_each_child_of_node(e1,n) S
|
for_each_available_child_of_node(e1,n) S
|
for_each_node_with_property(n,e1) S
)
&
i(es,n,...) S
)

@@
local idexpression r.n;
iterator r.i;
expression e;
expression list [r.n1] es;
@@

 i(es,n,...) {
   ...
(
   of_node_put(n);
|
   e = n
|
   return n;
|
+  of_node_put(n);
?  return ...;
)
   ...
 }

@@
local idexpression r.n;
iterator r.i;
expression e;
expression list [r.n1] es;
@@

 i(es,n,...) {
   ...
(
   of_node_put(n);
|
   e = n
|
+  of_node_put(n);
?  break;
)
   ...
 }
... when != n

@@
local idexpression r.n;
iterator r.i;
expression e;
identifier l;
expression list [r.n1] es;
@@

 i(es,n,...) {
   ...
(
   of_node_put(n);
|
   e = n
|
+  of_node_put(n);
?  goto l;
)
   ...
 }
...
l: ... when != n// </smpl>
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

for_each_available_child_of_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
expression root,e;
local idexpression child;
@@

 for_each_available_child_of_node(root, child) {
   ... when != of_node_put(child)
       when != e = child
(
   return child;
|
+  of_node_put(child);
?  return ...;
)
   ...
 }
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

for_each_compatible_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
expression e;
local idexpression n;
@@

 for_each_compatible_node(n,...) {
   ... when != of_node_put(n)
       when != e = n
(
   return n;
|
+  of_node_put(n);
?  return ...;
)
   ...
 }
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

for_each_available_child_of_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
expression root,e;
local idexpression child;
@@

 for_each_available_child_of_node(root, child) {
   ... when != of_node_put(child)
       when != e = child
(
   return child;
|
+  of_node_put(child);
?  return ...;
)
   ...
 }
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

for_each_available_child_of_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
local idexpression r.n;
expression r,e;
@@

 for_each_available_child_of_node(r,n) {
   ...
(
   of_node_put(n);
|
   e = n
|
+  of_node_put(n);
?  break;
)
   ...
 }
... when != n
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

for_each_child_of_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
local idexpression r.n;
expression r,e;
@@

 for_each_child_of_node(r,n) {
   ...
(
   of_node_put(n);
|
   e = n
|
+  of_node_put(n);
?  break;
)
   ...
 }
... when != n
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

for_each_child_of_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
local idexpression r.n;
expression r,e;
@@

 for_each_child_of_node(r,n) {
   ...
(
   of_node_put(n);
|
   e = n
|
+  of_node_put(n);
?  break;
)
   ...
 }
... when != n
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

gre_gso_segment() chokes if SIT frames were aggregated by GRO engine.

Fixes: 61c1db7f ("ipv6: sit: add GSO/TSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sergei Shtylyov says:

====================
sh_eth: RX buffer alignment fixes

Here's a set of 2 patches against DaveM's 'net.git' repo which are the
fixes to the RX buffer size calculation.

[1/2] sh_eth: fix RX buffer size alignment
[2/2] sh_eth: fix RX buffer size calculation
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The RX buffer size calulation failed to account for the length granularity
(which is now 32 bytes)...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Both  Renesas R-Car and RZ/A1 manuals state that RX buffer  length must be
a multiple of 32 bytes, while the driver  only uses 16 byte granularity...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Claudiu Manoil says:

====================
gianfar: Misc. fixes and updates

Various fixes for some older issues, including having a
MAINTAINERS entry for this driver.
I'd recommend applying them on top of net, thanks.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The Rx BSY error interrupt indicates that a frame was
received and discarded due to lack of buffers, so it's
a rx ring overflow condition and has nothing to do with
with bad rx packets.  Use the right counter.

BSY conditions happen when the SoC is under performance
stress.  Doing *more* work in stress situations by trying
to schedule NAPI is not a good idea as the stressed system
becomes still more stressed.  The Rx interrupt is already
at work making sure the NAPI is scheduled.
So calling gfar_receive() here does not help.  This issue
was present since day 1.
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Under one unusual circumstance it's possible to wrongly set
FILREN without enabling PRSDEP as well in the RCTRL register,
against the hardware specifications.  With the default config
this does not happen because the default Rx offloads (Rx csum
and Rx VLAN) properly enable PRSDEP.  But if anyone disables
all these offloads (via ethtool), we get a wrong configuration
were the Rx flow classification and hashing, and other Filer
based features (e.g. wake-on-filer interrupt) won't work.
This patch fixes the issue.
Also, account for Rx FCB insertion which happens every time
PRSDEP is set.
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RQFCR_AND is duplicated.
Add missing space as well.
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

David Daney says:

====================
net: thunderx: Support pass-2 revision hardware.

With the availability of a new revision of the ThunderX NIC hardware a
few changes to the driver are required.  With these, the driver works
on all currently available hardware revisions.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for ThunderX pass2 CPI and MPI configuration changes.
MPI_ALG is not enabled i.e MCAM parsing is disabled.
Signed-off-by: Thanneeru Srinivasulu <tsrinivasulu@caviumnetworks.com>
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The test for pass-1 silicon was incorrect, it should be for all
revisions less than 8.  Also the revision is already present in the
pci_dev, so there is no need to read and keep a private copy.

Remove rev_id and code to read it from struct nicpf.  Create new
static inline function pass1_silicon() to be used to testing the
silicon version.  Use pass1_silicon() for revision checks, this will
be more widely used in follow on patches.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In some silicon revisions, the soft reset clobbers PCI config space,
so quit doing the reset.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

the returned buffer of register_sysctl() is stored into net_header
variable, but net_header is not used after, and compiler maybe
optimise the variable out, and lead kmemleak reported the below warning

	comm "swapper/0", pid 1, jiffies 4294937448 (age 267.270s)
	hex dump (first 32 bytes):
	90 38 8b 01 c0 ff ff ff 00 00 00 00 01 00 00 00 .8..............
	01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
	backtrace:
	[<ffffffc00020f134>] create_object+0x10c/0x2a0
	[<ffffffc00070ff44>] kmemleak_alloc+0x54/0xa0
	[<ffffffc0001fe378>] __kmalloc+0x1f8/0x4f8
	[<ffffffc00028e984>] __register_sysctl_table+0x64/0x5a0
	[<ffffffc00028eef0>] register_sysctl+0x30/0x40
	[<ffffffc00099c304>] net_sysctl_init+0x20/0x58
	[<ffffffc000994dd8>] sock_init+0x10/0xb0
	[<ffffffc0000842e0>] do_one_initcall+0x90/0x1b8
	[<ffffffc000966bac>] kernel_init_freeable+0x218/0x2f0
	[<ffffffc00070ed6c>] kernel_init+0x1c/0xe8
	[<ffffffc000083bfc>] ret_from_fork+0xc/0x50
	[<ffffffffffffffff>] 0xffffffffffffffff <<end check kmemleak>>

Before fix, the objdump result on ARM64:
0000000000000000 <net_sysctl_init>:
   0:   a9be7bfd        stp     x29, x30, [sp,#-32]!
   4:   90000001        adrp    x1, 0 <net_sysctl_init>
   8:   90000000        adrp    x0, 0 <net_sysctl_init>
   c:   910003fd        mov     x29, sp
  10:   91000021        add     x1, x1, #0x0
  14:   91000000        add     x0, x0, #0x0
  18:   a90153f3        stp     x19, x20, [sp,#16]
  1c:   12800174        mov     w20, #0xfffffff4                // #-12
  20:   94000000        bl      0 <register_sysctl>
  24:   b4000120        cbz     x0, 48 <net_sysctl_init+0x48>
  28:   90000013        adrp    x19, 0 <net_sysctl_init>
  2c:   91000273        add     x19, x19, #0x0
  30:   9101a260        add     x0, x19, #0x68
  34:   94000000        bl      0 <register_pernet_subsys>
  38:   2a0003f4        mov     w20, w0
  3c:   35000060        cbnz    w0, 48 <net_sysctl_init+0x48>
  40:   aa1303e0        mov     x0, x19
  44:   94000000        bl      0 <register_sysctl_root>
  48:   2a1403e0        mov     w0, w20
  4c:   a94153f3        ldp     x19, x20, [sp,#16]
  50:   a8c27bfd        ldp     x29, x30, [sp],#32
  54:   d65f03c0        ret
After:
0000000000000000 <net_sysctl_init>:
   0:   a9bd7bfd        stp     x29, x30, [sp,#-48]!
   4:   90000000        adrp    x0, 0 <net_sysctl_init>
   8:   910003fd        mov     x29, sp
   c:   a90153f3        stp     x19, x20, [sp,#16]
  10:   90000013        adrp    x19, 0 <net_sysctl_init>
  14:   91000000        add     x0, x0, #0x0
  18:   91000273        add     x19, x19, #0x0
  1c:   f90013f5        str     x21, [sp,#32]
  20:   aa1303e1        mov     x1, x19
  24:   12800175        mov     w21, #0xfffffff4                // #-12
  28:   94000000        bl      0 <register_sysctl>
  2c:   f9002260        str     x0, [x19,#64]
  30:   b40001a0        cbz     x0, 64 <net_sysctl_init+0x64>
  34:   90000014        adrp    x20, 0 <net_sysctl_init>
  38:   91000294        add     x20, x20, #0x0
  3c:   9101a280        add     x0, x20, #0x68
  40:   94000000        bl      0 <register_pernet_subsys>
  44:   2a0003f5        mov     w21, w0
  48:   35000080        cbnz    w0, 58 <net_sysctl_init+0x58>
  4c:   aa1403e0        mov     x0, x20
  50:   94000000        bl      0 <register_sysctl_root>
  54:   14000004        b       64 <net_sysctl_init+0x64>
  58:   f9402260        ldr     x0, [x19,#64]
  5c:   94000000        bl      0 <unregister_sysctl_table>
  60:   f900227f        str     xzr, [x19,#64]
  64:   2a1503e0        mov     w0, w21
  68:   f94013f5        ldr     x21, [sp,#32]
  6c:   a94153f3        ldp     x19, x20, [sp,#16]
  70:   a8c37bfd        ldp     x29, x30, [sp],#48
  74:   d65f03c0        ret

Add the possible error handle to free the net_header to remove the
kmemleak warning
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We can't rely on PPPOX_ZOMBIE to decide whether to clear po->pppoe_dev.
PPPOX_ZOMBIE can be set by pppoe_disc_rcv() even when po->pppoe_dev is
NULL. So we have no guarantee that (sk->sk_state & PPPOX_ZOMBIE) implies
(po->pppoe_dev != NULL).
Since we're releasing a PPPoE socket, we want to release the pppoe_dev
if it exists and reset sk_state to PPPOX_DEAD, no matter the previous
value of sk_state. So we can just check for po->pppoe_dev and avoid any
assumption on sk->sk_state.

Fixes: 2b018d57 ("pppoe: drop PPPOX_ZOMBIEs in pppoe_release")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The code currently uses the lightweight dma_wmb barrier before updating
the current descriptor count. Under heavy load, the Tx cleanup routine
was seeing the updated current descriptor count before the updated
descriptor information. As a result, the Tx descriptor was being cleaned
up before it was used because it was not "owned" by the hardware yet,
resulting in a Tx queue hang.

Using the wmb barrier insures that the descriptor is updated before the
descriptor counter preventing the Tx queue hang. For extra insurance,
the Tx cleanup routine is changed to grab the current decriptor count on
entry and uses that initial value in the processing loop rather than
trying to chase the current value.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Very rarely, the KSZ9031 will appear to complete autonegotiation, but
will drop all traffic afterwards.  When this happens, the idle error
count will read 0xFF after autonegotiation completes.  Reset the PHY
when in that state.
Signed-off-by: Nathan Sullivan <nathan.sullivan@ni.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Hannes Frederic Sowa says:

====================
overflow-arith: begin to add support for overflow builtins functions

I add a new header, linux/overflow-arith.h, as the central place to add
overflow and wrap-around checking functions. The reason I am doing so
is that it can make use of compiler supported builtin functions which
can leverage hardware.

As I need this for a fix in the ipv6 stack, which is also included in
this series, I propose to add it sooner than later over Davem's net
tree. This is also the reason why I start slowly with only the one
function I need at this time.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Raw sockets with hdrincl enabled can insert ipv6 extension headers
right into the data stream. In case we need to fragment those packets,
we reparse the options header to find the place where we can insert
the fragment header. If the extension headers exceed the link's MTU we
actually cannot make progress in such a case.

Instead of ending up in broken arithmetic or rounding towards 0 and
entering an endless loop in ip6_fragment, just prevent those cases by
aborting early and signal -EMSGSIZE to user space.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The idea of the overflow-arith.h header is to collect overflow checking
functions in one central place.

If gcc compiler supports the __builtin_overflow_* builtins we use them
because they might give better performance, otherwise the code falls
back to normal overflow checking functions.

The builtin_overflow functions are supported by gcc-5 and clang. The
matter of supporting clang is to just provide a corresponding
CC_HAVE_BUILTIN_OVERFLOW, because the specific overflow checking builtins
don't differ between gcc and clang.

I just provide overflow_usub function here as I intend this to get merged
into net, more functions will definitely follow as they are needed.
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

If alpha is strictly reduced by alpha >> dctcp_shift_g and if alpha is less
than 1 << dctcp_shift_g, then alpha may never reach zero. For example,
given shift_g=4 and alpha=15, alpha >> dctcp_shift_g yields 0 and alpha
remains 15. The effect isn't noticeable in this case below cwnd=137, but
could gradually drive uncongested flows with leftover alpha down to
cwnd=137. A larger dctcp_shift_g would have a greater effect.

This change causes alpha=15 to drop to 0 instead of being decrementing by 1
as it would when alpha=16. However, it requires one less conditional to
implement since it doesn't have to guard against subtracting 1 from 0U. A
decay of 15 is not unreasonable since an equal or greater amount occurs at
alpha >= 240.
Signed-off-by: Andrew G. Shewmaker <agshew@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The error condition -EAGAIN, which is signaled by throw routes, tells
the rules framework to walk on searching for next matches. If the walk
ends and we stop walking the rules with the result of a throw route we
have to translate the error conditions to -ENETUNREACH.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

We don't have fraglist support in TAP_FEATURES. This will lead
software segmentation of gro skb with frag list. Fixes by having
frag list support in TAP_FEATURES.

With this patch single session of netperf receiving were restored from
about 5Gb/s to about 12Gb/s on mlx4.

Fixes a567dd62 ("macvtap: simplify usage of tap_features")
Cc: Vlad Yasevich <vyasevic@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

While transitioning to netdev based vport we broke OVS
feature which allows user to retrieve tunnel packet egress
information for lwtunnel devices.  Following patch fixes it
by introducing ndo operation to get the tunnel egress info.
Same ndo operation can be used for lwtunnel devices and compat
ovs-tnl-vport devices. So after adding such device operation
we can remove similar operation from ovs-vport.

Fixes: 614732ea ("openvswitch: Use regular VXLAN net_device device").
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
Intel Wired LAN Driver Updates 2015-10-22

This series contains fixes to i40e only.

Jesse provides two small fixes for i40e, first fixes counters that were
being displayed incorrectly due to indexing beyond the array of strings
when printing stats.  Then fixed the fact that the driver was printing
a message about not being able to assign VMDq because a lack of MSI-X
vectors, when it was not true.  It was due to a line missing that
initialized a variable.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The recent fix for the vsock sock_put issue used the wrong
initializer for the transport spin_lock causing an issue when
running with lockdep checking.

Testing: Verified fix on kernel with lockdep enabled.
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The driver was printing a message about not being able
to assign VMDq because of a lack of MSI-X vectors.

This was because a line was missing that initialized a variable,
simply a merge error.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The code was setting up stats that were not being initialized.
This caused several counters to be displayed incorrectly, due
to indexing beyond the array of strings when printing stats.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

New device IDs shamelessly lifted from the vendor driver.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

Steffen Klassert says:

====================
pull request (net): ipsec 2015-10-22

1) Fix IPsec pre-encap fragmentation for GSO packets.
   From Herbert Xu.

2) Fix some header checks in _decode_session6.
   We skip the header informations if the data pointer points
   already behind the header in question for some protocols.
   This is because we call pskb_may_pull with a negative value
   converted to unsigened int from pskb_may_pull in this case.
   Skipping the header informations can lead to incorrect policy
   lookups. From Mathias Krause.

3) Allow to change the replay threshold and expiry timer of a
   state without having to set other attributes like replay
   counter and byte lifetime. Changing these other attributes
   may break the SA. From Michael Rossberg.

4) Fix pmtu discovery for local generated packets.
   We may fail dispatch to the inner address family.
   As a reault, the local error handler is not called
   and the mtu value is not reported back to userspace.

Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

741a11d9 ("net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set")
adds the RT6_LOOKUP_F_IFACE flag to make device index mismatch fatal if
oif is given. Hajime reported that this change breaks the Mobile IPv6
use case that wants to force the message through one interface yet use
the source address from another interface. Handle this case by only
adding the flag if oif is set and saddr is not set.

Fixes: 741a11d9 ("net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set")
Cc: Hajime Tazaki <thehajime@gmail.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>