Pass a dscp_t variable to ip_route_input_noref(), instead of a plain
u8, to prevent accidental setting of ECN bits in ->flowi4_tos.
Callers of ip_route_input_noref() to consider are:
* arp_process() in net/ipv4/arp.c. This function sets the tos
parameter to 0, which is already a valid dscp_t value, so it
doesn't need to be adjusted for the new prototype.
* ip_route_input(), which already has a dscp_t variable to pass as
parameter. We just need to remove the inet_dscp_to_dsfield()
conversion.
* ipvlan_l3_rcv(), bpf_lwt_input_reroute(), ip_expire(),
ip_rcv_finish_core(), xfrm4_rcv_encap_finish() and
xfrm4_rcv_encap(), which get the DSCP directly from IPv4 headers
and can simply use the ip4h_dscp() helper.
While there, declare the IPv4 header pointers as const in
ipvlan_l3_rcv() and bpf_lwt_input_reroute().
Also, modify the declaration of ip_route_input_noref() in
include/net/route.h so that it matches the prototype of its
implementation in net/ipv4/route.c.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/a8a747bed452519c4d0cc06af32c7e7795d7b627.1727807926.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
66fb6386d3