Merge branch 'ipv4-handle-tos-and-scope-properly-for-icmp-redirects-and-pmtu-updates'

Guillaume Nault says:

====================
ipv4: Handle TOS and scope properly for ICMP redirects and PMTU updates

ICMPv4 PMTU and redirect handlers didn't properly initialise the
struct flowi4 they used for route lookups:

  * ECN bits sometimes weren't cleared from ->flowi4_tos.
  * The RTO_ONLINK flag wasn't taken into account for ->flowi4_scope.

In some special cases, this resulted in ICMP redirects and PMTU updates
not being taken into account because fib_lookup() couldn't retrieve the
correct route.
====================

Link: https://lore.kernel.org/r/cover.1647519748.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>