ipv4: Set correct scope in inet_csk_route_*().

RT_CONN_FLAGS(sk) overloads the tos parameter with the RTO_ONLINK bit
when sk has the SOCK_LOCALROUTE flag set. This is only useful for
ip_route_output_key_hash() to eventually adjust the route scope.

Let's drop RTO_ONLINK and set the correct scope directly to avoid this
special case in the future and to allow converting ->flowi4_tos to
dscp_t.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/ipv4/inet_connection_sock.c

@@ -792,7 +792,7 @@ struct dst_entry *inet_csk_route_req(const struct sock *sk,
 	opt = rcu_dereference(ireq->ireq_opt);
 
 	flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
-			   RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
+			   ip_sock_rt_tos(sk), ip_sock_rt_scope(sk),
 			   sk->sk_protocol, inet_sk_flowi_flags(sk),
 			   (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
 			   ireq->ir_loc_addr, ireq->ir_rmt_port,
@@ -830,7 +830,7 @@ struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
 	fl4 = &newinet->cork.fl.u.ip4;
 
 	flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
-			   RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
+			   ip_sock_rt_tos(sk), ip_sock_rt_scope(sk),
 			   sk->sk_protocol, inet_sk_flowi_flags(sk),
 			   (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
 			   ireq->ir_loc_addr, ireq->ir_rmt_port,