Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: 0ce1822c2a08 ("vxlan: add adjacent link to limit depth level")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1606903122-2098-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

While vxlan doesn't need any extra tailroom, the lowerdev might need it. In
that case, copy it over to reduce the chance for additional (re)allocations
in the transmit path.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Link: https://lore.kernel.org/r/20201126125247.1047977-2-sven@narfation.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

It was observed that sending data via batadv over vxlan (on top of
wireguard) reduced the performance massively compared to raw ethernet or
batadv on raw ethernet. A check of perf data showed that the
vxlan_build_skb was calling all the time pskb_expand_head to allocate
enough headroom for:

  min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len
  		+ VXLAN_HLEN + iphdr_len;

But the vxlan_config_apply only requested needed headroom for:

  lowerdev->hard_header_len + VXLAN6_HEADROOM or VXLAN_HEADROOM

So it completely ignored the needed_headroom of the lower device. The first
caller of net_dev_xmit could therefore never make sure that enough headroom
was allocated for the rest of the transmit path.

Cc: Annika Wickert <annika.wickert@exaring.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Tested-by: Annika Wickert <aw@awlnx.space>
Link: https://lore.kernel.org/r/20201126125247.1047977-1-sven@narfation.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

use new helper for netstats settings

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

This reverts commit 546c044c9651e81a16833806feff6b369bb5de33.

Nothing prevents user from sending frames to "external" VxLAN devices.
In fact kernel itself may generate icmp chatter.

This is fine, such frames should be dropped.

The point of the "missing encapsulation" warning was that
frames with missing encap should not make it into vxlan_xmit_one().
And vxlan_xmit() drops them cleanly, so let it just do that.

Without this revert the warning is triggered by the udp_tunnel_nic.sh
test, but the minimal repro is:

$ ip link add vxlan0 type vxlan \
     	      	     group 239.1.1.1 \
		     dev lo \
		     dstport 1234 \
		     external
$ ip li set dev vxlan0 up

[  419.165981] vxlan0: Missing encapsulation instructions
[  419.166551] WARNING: CPU: 0 PID: 1041 at drivers/net/vxlan.c:2889 vxlan_xmit+0x15c0/0x1fc0 [vxlan]

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since commit aab8cc3630e32
("vxlan: add support for underlay in non-default VRF")

vxlan_find_sock() also checks if socket is assigned to the right
level 3 master device when lower device is not in the default VRF.

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

rtnl_configure_link is always checked if < 0 for error code.

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

vxlan_xmit_one() was only called from vxlan_xmit() without rdst and
info was already tested. Emit warning in that function instead

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

small optimization around checking as it's being done in all
receptions

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

call vxlan_remcsum() before md filling in vxlan_rcv()

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