linux-stable/include/uapi
Stefano Brivio b4d3069783 vxlan: Allow configuration of DF behaviour
Allow users to set the IPv4 DF bit in outgoing packets, or to inherit its
value from the IPv4 inner header. If the encapsulated protocol is IPv6 and
DF is configured to be inherited, always set it.

For IPv4, inheriting DF from the inner header was probably intended from
the very beginning judging by the comment to vxlan_xmit(), but it wasn't
actually implemented -- also because it would have done more harm than
good, without handling for ICMP Fragmentation Needed messages.

According to RFC 7348, "Path MTU discovery MAY be used". An expired RFC
draft, draft-saum-nvo3-pmtud-over-vxlan-05, whose purpose was to describe
PMTUD implementation, says that "is a MUST that Vxlan gateways [...]
SHOULD set the DF-bit [...]", whatever that means.

Given this background, the only sane option is probably to let the user
decide, and keep the current behaviour as default.

This only applies to non-lwt tunnels: if an external control plane is
used, tunnel key will still control the DF flag.

v2:
- DF behaviour configuration only applies for non-lwt tunnels, move DF
  setting to if (!info) block in vxlan_xmit_one() (Stephen Hemminger)

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-08 17:13:08 -08:00
..
asm-generic TTY/Serial patches for 4.20-rc1 2018-10-29 10:42:20 -07:00
drm Add out-bridge support 2018-10-04 10:40:54 +10:00
linux vxlan: Allow configuration of DF behaviour 2018-11-08 17:13:08 -08:00
misc ocxl: Add an IOCTL so userspace knows what OCXL features are available 2018-06-03 20:40:32 +10:00
mtd ubi: expose the volume CRC check skip flag 2018-08-15 00:25:21 +02:00
rdma IB/mlx5: Allow scatter to CQE without global signaled WRs 2018-10-17 11:25:41 -04:00
scsi scsi: ufs: fix integer type usage in uapi header 2018-10-15 22:44:30 -04:00
sound Merge branch 'for-linus' into for-next 2018-10-04 07:53:06 +02:00
video
xen xen/gntdev: Add initial support for dma-buf UAPI 2018-07-26 23:05:14 -04:00