From a3522a2edb3faf8cb98d38c2a99f5967beef24e2 Mon Sep 17 00:00:00 2001 From: Guillaume Nault Date: Fri, 9 Feb 2024 17:43:37 +0100 Subject: ipv4: Set the routing scope properly in ip_route_output_ports(). Set scope automatically in ip_route_output_ports() (using the socket SOCK_LOCALROUTE flag). This way, callers don't have to overload the tos with the RTO_ONLINK flag, like RT_CONN_FLAGS() does. For callers that don't pass a struct sock, this doesn't change anything as the scope is still set to RT_SCOPE_UNIVERSE when sk is NULL. Callers that passed a struct sock and used RT_CONN_FLAGS(sk) or RT_CONN_FLAGS_TOS(sk, tos) for the tos are modified to use ip_sock_tos(sk) and RT_TOS(tos) respectively, as overloading tos with the RTO_ONLINK flag now becomes unnecessary. In drivers/net/amt.c, all ip_route_output_ports() calls use a 0 tos parameter, ignoring the SOCK_LOCALROUTE flag of the socket. But the sk parameter is a kernel socket, which doesn't have any configuration path for setting SOCK_LOCALROUTE anyway. Therefore, ip_route_output_ports() will continue to initialise scope with RT_SCOPE_UNIVERSE and amt.c doesn't need to be modified. Also, remove RT_CONN_FLAGS() and RT_CONN_FLAGS_TOS() from route.h as these macros are now unused. The objective is to eventually remove RTO_ONLINK entirely to allow converting ->flowi4_tos to dscp_t. This will ensure proper isolation between the DSCP and ECN bits, thus minimising the risk of introducing bugs where TOS values interfere with ECN. Signed-off-by: Guillaume Nault Reviewed-by: David Ahern Link: https://lore.kernel.org/r/dacfd2ab40685e20959ab7b53c427595ba229e7d.1707496938.git.gnault@redhat.com Signed-off-by: Jakub Kicinski --- include/net/route.h | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'include/net') diff --git a/include/net/route.h b/include/net/route.h index 980ab474eabd..d4a0147942f1 100644 --- a/include/net/route.h +++ b/include/net/route.h @@ -37,9 +37,6 @@ #define RTO_ONLINK 0x01 -#define RT_CONN_FLAGS(sk) (RT_TOS(READ_ONCE(inet_sk(sk)->tos)) | sock_flag(sk, SOCK_LOCALROUTE)) -#define RT_CONN_FLAGS_TOS(sk,tos) (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE)) - static inline __u8 ip_sock_rt_scope(const struct sock *sk) { if (sock_flag(sk, SOCK_LOCALROUTE)) @@ -163,8 +160,8 @@ static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi __u8 proto, __u8 tos, int oif) { flowi4_init_output(fl4, oif, sk ? READ_ONCE(sk->sk_mark) : 0, tos, - RT_SCOPE_UNIVERSE, proto, - sk ? inet_sk_flowi_flags(sk) : 0, + sk ? ip_sock_rt_scope(sk) : RT_SCOPE_UNIVERSE, + proto, sk ? inet_sk_flowi_flags(sk) : 0, daddr, saddr, dport, sport, sock_net_uid(net, sk)); if (sk) security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4)); -- cgit v1.2.3