Re: [PATCH net-next] ipv4: Remove RTO_ONLINK.

[Przemek Kitszel <przemyslaw.kitszel@intel.com>]

On 4/10/24 15:14, Guillaume Nault wrote:
> RTO_ONLINK was a flag used in ->flowi4_tos that allowed to alter the
> scope of an IPv4 route lookup. Setting this flag was equivalent to
> specifying RT_SCOPE_LINK in ->flowi4_scope.
> 
> With commit ec20b2830093 ("ipv4: Set scope explicitly in
> ip_route_output()."), the last users of RTO_ONLINK have been removed.
> Therefore, we can now drop the code that checked this bit and stop
> modifying ->flowi4_scope in ip_route_output_key_hash().
> 
> Signed-off-by: Guillaume Nault <gnault@redhat.com>
> ---
>   include/net/route.h |  2 --
>   net/ipv4/route.c    | 14 +-------------
>   2 files changed, 1 insertion(+), 15 deletions(-)
> 
> diff --git a/include/net/route.h b/include/net/route.h
> index 315a8acee6c6..630d1ef6868a 100644
> --- a/include/net/route.h
> +++ b/include/net/route.h
> @@ -35,8 +35,6 @@
>   #include <linux/cache.h>
>   #include <linux/security.h>
>   
> -#define RTO_ONLINK	0x01
> -
>   static inline __u8 ip_sock_rt_scope(const struct sock *sk)
>   {
>   	if (sock_flag(sk, SOCK_LOCALROUTE))
> diff --git a/net/ipv4/route.c b/net/ipv4/route.c
> index c8f76f56dc16..bc6759e07a6f 100644
> --- a/net/ipv4/route.c
> +++ b/net/ipv4/route.c
> @@ -106,9 +106,6 @@
>   
>   #include "fib_lookup.h"
>   
> -#define RT_FL_TOS(oldflp4) \
> -	((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
> -
>   #define RT_GC_TIMEOUT (300*HZ)
>   
>   #define DEFAULT_MIN_PMTU (512 + 20 + 20)
> @@ -498,15 +495,6 @@ void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
>   }
>   EXPORT_SYMBOL(__ip_select_ident);
>   
> -static void ip_rt_fix_tos(struct flowi4 *fl4)
> -{
> -	__u8 tos = RT_FL_TOS(fl4);
> -
> -	fl4->flowi4_tos = tos & IPTOS_RT_MASK;
> -	if (tos & RTO_ONLINK)
> -		fl4->flowi4_scope = RT_SCOPE_LINK;
> -}
> -
>   static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
>   			     const struct sock *sk, const struct iphdr *iph,
>   			     int oif, __u8 tos, u8 prot, u32 mark,
> @@ -2638,7 +2626,7 @@ struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
>   	struct rtable *rth;
>   
>   	fl4->flowi4_iif = LOOPBACK_IFINDEX;
> -	ip_rt_fix_tos(fl4);
> +	fl4->flowi4_tos &= IPTOS_RT_MASK;
>   
>   	rcu_read_lock();
>   	rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>