From 4b095281cacab0b62e7f11d6d8c4a6d49ecaae42 Mon Sep 17 00:00:00 2001
From: Guillaume Nault <gnault@redhat.com>
Date: Mon, 5 Jun 2023 23:55:25 +0200
Subject: [PATCH 1/2] 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 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 1386787eaf1a5..15424dec45842 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/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,

From 6f8a76f8022121f7e4dc9cc29da7fb716b7db45f Mon Sep 17 00:00:00 2001
From: Guillaume Nault <gnault@redhat.com>
Date: Mon, 5 Jun 2023 23:55:30 +0200
Subject: [PATCH 2/2] tcp: Set route scope properly in cookie_v4_check().

RT_CONN_FLAGS(sk) overloads flowi4_tos with the RTO_ONLINK bit when
sk has the SOCK_LOCALROUTE flag set. This allows
ip_route_output_key_hash() to eventually adjust flowi4_scope.

Instead of relying on special handling of the RTO_ONLINK bit, we can
just set the route scope correctly. This will eventually allow to avoid
special interpretation of tos variables and to convert ->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/syncookies.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 26fb97d1d4d9a..dc478a0574cbe 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -418,8 +418,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
 	 * no easy way to do this.
 	 */
 	flowi4_init_output(&fl4, ireq->ir_iif, ireq->ir_mark,
-			   RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, IPPROTO_TCP,
-			   inet_sk_flowi_flags(sk),
+			   ip_sock_rt_tos(sk), ip_sock_rt_scope(sk),
+			   IPPROTO_TCP, inet_sk_flowi_flags(sk),
 			   opt->srr ? opt->faddr : ireq->ir_rmt_addr,
 			   ireq->ir_loc_addr, th->source, th->dest, sk->sk_uid);
 	security_req_classify_flow(req, flowi4_to_flowi_common(&fl4));